Back to BVA DecisionsMIXEDSpecial Benefit TDIU; EARLIER EFFECTIVE DATE Diagnostic Code 7005 Docket No. 211029-194268
ARTERIOSCLEROTIC HEART DISEASE (CORONARY ARTERY DISEASE)
TANYA SMITH · 2025 · Case ID: A25053853
Summary
The veteran, who served from November 1971 to September 1973, appeals multiple denials and seeks an earlier effective date for a granted rating. The Board granted service connection for diabetes mellitus, left and right lower extremity diabetic peripheral neuropathy, erectile dysfunction, and sleep disturbed breathing (sleep apnea). The diabetes mellitus claim was granted secondary to service-connected labile hypertension, with the Board finding the private physician's opinion more probative than the VA examiner's, resolving doubt in the veteran's favor due to the absence of family history and the documented bidirectional causal relationship between hypertension and diabetes. The peripheral neuropathy and erectile dysfunction claims were granted secondary to the newly service-connected diabetes mellitus, supported by both VA and private medical opinions. The sleep apnea claim was granted secondary to service-connected labile hypertension, with the Board finding the private physician's opinion persuasive in establishing the nexus. The claim for an increased rating for coronary artery disease (CAD) to 60 percent, effective prior to February 23, 2021, was denied, as the evidence did not meet the pre-amendment criteria for that rating level, with METs and LVEF results not supporting the higher evaluation. The Board found the evidence persuasively against the claim, making the benefit of the doubt doctrine inapplicable. The claim for Total Disability based on Individual Unemployability (TDIU) was remanded for adjudication after disability ratings and effective dates are assigned for the newly granted conditions.
Rationale
Evidence did not meet pre-amendment criteria for 60% rating; METs levels and LVEF results did not satisfy thresholds; No evidence of left ventricular dysfunction or specific METs/LVEF results supporting 60% rating
Full Decision Text
Citation Nr: A25053853 Decision Date: 06/23/25 Archive Date: 06/23/25 DOCKET NO. 211029-194268 DATE: June 23, 2025 ORDER Prior to February 23, 2021, entitlement to a 60 percent rating for coronary artery disease (CAD) is denied. Entitlement to service connection for diabetes mellitus is granted. Entitlement to service connection for left lower extremity diabetic peripheral neuropathy is granted. Entitlement to service connection for right lower extremity diabetic peripheral neuropathy is granted. Entitlement to service connection for erectile dysfunction is granted. Entitlement to service connection for sleep disturbed breathing, to include sleep apnea, is granted. REMANDED Entitlement to a total disability rating based on individual unemployability due to service-connected disabilities (TDIU) is remanded. FINDINGS OF FACT 1. Prior to February 23, 2021, the Veteran's CAD did not manifest in more than one episode of acute congestive heart failure in the past year, or; a workload of greater than 3.0 METs but not greater than 5.0 METs resulting in dyspnea, fatigue, angina, dizziness, or syncope, or; left ventricular dysfunction with an ejection fraction of 30 to 50 percent. 2. Resolving reasonable doubt in the Veteran's favor, his diabetes mellitus was caused by his service-connected labile hypertension. 3. The Veteran's left lower extremity diabetic peripheral neuropathy was caused by his diabetes mellitus. 4. The Veteran's right lower extremity diabetic peripheral neuropathy was caused by his diabetes mellitus. 5. The Veteran's erectile dysfunction was caused by his diabetes mellitus. 6. The Veteran's sleep disturbed breathing, to include sleep apnea, was caused by his service-connected labile hypertension. CONCLUSIONS OF LAW 1. Prior to February 23, 2021, the criteria for entitlement to a 60 percent rating for CAD have not been met. 38 U.S.C. §§ 1155, 5107, 5110; 38 C.F.R. §§ 3.400, 4.1, 4.3, 4.7, 4.100, 4.104, Diagnostic Code 7005. 2. The criteria for entitlement to service connection for diabetes mellitus have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.310. 3. The criteria for entitlement to service connection for left lower extremity diabetic peripheral neuropathy have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.310. 4. The criteria for entitlement to service connection for right lower extremity diabetic peripheral neuropathy have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.310. 5. The criteria for entitlement to service connection for erectile dysfunction have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.310. 6. The criteria for entitlement to service connection for sleep disturbed breathing, to include sleep apnea, have been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.303, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from November 1971 to September 1973. This matter comes before the Board on appeal from November 2020, March 8, 2021, and March 16, 2021, Regional Office (RO) rating decisions. The Veteran was notified of these decisions in letters dated November 3, 2020, March 9, 2021, and March 17, 2021, respectively. The claims of entitlement to service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, and erectile dysfunction were denied in a December 9, 2019, rating decision. The Veteran was notified of this decision in a letter dated December 11, 2019. In November 2020, the Veteran submitted a VA Form 20-0996, Decision Review Request: Higher-Level Review, in which he requested a Higher-Level Review of the December 2019 decision. In March 2021, the RO issued a Higher-Level Review rating decision that denied service connection for diabetes 9, 2021, and March 17, 2021, respectively. The claims of entitlement to service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, and erectile dysfunction were denied in a December 9, 2019, rating decision. The Veteran was notified of this decision in a letter dated December 11, 2019. In November 2020, the Veteran submitted a VA Form 20-0996, Decision Review Request: Higher-Level Review, in which he requested a Higher-Level Review of the December 2019 decision. In March 2021, the RO issued a Higher-Level Review rating decision that denied service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, and erectile dysfunction. That decision was issued in a letter dated March 9, 2021. On October 29, 2021, the Veteran submitted a VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), on which he listed the March 9, 2021, rating decision notification letter and the denials of service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, and erectile dysfunction. He selected the Evidence Submission Docket. When cases are adjudicated under the evidence submission docket, the Board may only consider (a) the evidence that was of record at the time of the agency of original jurisdiction (AOJ) decision on the issue or issues on appeal, and (b) evidence that was submitted by the appellant or his or her representative with the notice of disagreement (VA Form 10182) or within 90 days following receipt of the notice of disagreement. 38 C.F.R. § 20.303. The first evidentiary window for the claims of entitlement to service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, and erectile dysfunction closes on December 11, 2019, which is the date of the notification letter for the underlying rating decision that was subject to Higher-Level Review. The second evidentiary window spans from October 29, 2021, which is the date on which VA received the VA Form 10182, to January 27, 2022. The claim of entitlement to service connection for sleep apnea was denied by the RO in a January 6, 2020, rating decision. The Veteran was notified of this decision in a letter dated January 8, 2020. In November 2020, the Veteran submitted a VA Form 20-0996, Decision Review Request: Higher-Level Review, in which he requested a Higher-Level Review of the January 2020 decision. In the March 2021 Higher-Level Review rating decision, the RO denied service connection for sleep apnea. That decision was issued in a letter dated March 9, 2021. On the October 29, 2021, VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), the Veteran listed the January 8, 2021, rating decision notification letter and the denial of service connection for sleep apnea. He selected the Evidence Submission Docket. The first evidentiary window for the claim of entitlement to service connection for sleep disturbed breathing, to include sleep apnea, closes on January 8, 2020, which is the date of the notification letter for the underlying rating decision that was subject to Higher-Level Review. The second evidentiary window spans from October 29, 2021, which is the date on which VA received the VA Form 10182, to January 27, 2022. (For reasons that will be addressed below, the issue of "entitlement to service connection for sleep apnea" has been recharacterized as "entitlement to service connection for sleep disturbed breathing, to include sleep apnea.") The claim of entitlement to a TDIU was denied by the RO in a November 2, 2020, rating decision. The Veteran was notified of this decision in a letter dated November 3, 2020. In the October 29, 2021, VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), the Veteran listed the November 3, 2020, rating decision notification letter and the denial of entitlement to a TDIU. He selected the Evidence Submission Docket. The first evidentiary window for the claim of entitlement to a TDIU closes on November 3, 2020, which is the date of the notification letter for the rating decision. The second evidentiary U was denied by the RO in a November 2, 2020, rating decision. The Veteran was notified of this decision in a letter dated November 3, 2020. In the October 29, 2021, VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), the Veteran listed the November 3, 2020, rating decision notification letter and the denial of entitlement to a TDIU. He selected the Evidence Submission Docket. The first evidentiary window for the claim of entitlement to a TDIU closes on November 3, 2020, which is the date of the notification letter for the rating decision. The second evidentiary window spans from October 29, 2021, which is the date on which VA received the VA Form 10182, to January 27, 2022. In a March 16, 2021, rating decision, the RO granted entitlement to a higher rating, increased from 30 percent to 60 percent, effective February 23, 2021. The Veteran was notified of this decision in a letter dated March 17, 2021. In the October 29, 2021, VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), the Veteran listed the March 17, 2021, rating decision notification letter and the CAD claim. He selected the Evidence Submission Docket. In a January 2022 written brief, the Veteran's then-representative specified that the Veteran is requesting entitlement to an earlier effective date for the grant of the 60 percent rating for CAD. The first evidentiary window for the claim of entitlement to an earlier effective date for the grant of a 60 percent rating for CAD closes on March 17, 2021, which is the date of the notification letter for the rating decision. The second evidentiary window spans from October 29, 2021, which is the date on which VA received the VA Form 10182, to January 27, 2022. Earlier Effective Date for Increased Rating Disability ratings are determined by comparing a veteran's symptoms with criteria listed in VA's Schedule for Rating Disabilities, which is based, as far as practically can be determined, on average impairment in earning capacity. 38 U.S.C. § 1155; 38 C.F.R. § Part 4. When there is a question as to which of two ratings to apply, the higher rating will be assigned if the disability picture more nearly approximates the criteria required for that rating; otherwise, the lower rating shall be assigned. 38 C.F.R. § 4.7. "Staged ratings," or different percentage evaluations for separate periods based on the facts found, may also be awarded. Fenderson v. West, 12 Vet. App. 119, 126-7 (1999); Hart v. Mansfield, 21 Vet. App. 505, 509-10 (2007). Caselaw requires the Board to take due consideration that the beneficial effects of medication are discounted unless such effects are otherwise contemplated in a particular diagnostic code. See Ingram v. Collins, No. 23-1798, ___ Vet. App. ___ (2025). Generally, the effective date for an award of service connection and disability compensation is the day following separation from active service, or the date entitlement arose if the claim is received within one year after separation from service; otherwise, for an award based on an original claim, a claim reopened after a final allowance, or a claim for an increase, the effective date will be the date of receipt of the claim or the date entitlement arose, whichever is later. 38 U.S.C. § 5110; 38 C.F.R. § 3.400. Under the AMA, an effective date can be preserved if the claim is continuously pursued by filing an appropriate administrative review option to an AMA decision, generally within one year from when the decision was issued. 38 C.F.R. § 3.2500(c). If an AMA claim is continuously pursued, it will be considered filed as of the date of the first claim in the continuously pursued chain, not the date the most recent request for review was received. 38 C.F.R. § 3.2500(h). For decisions rendered after a Higher-Level Review by the AOJ, continuous pursuit can be established by filing either a supplemental claim or a VA Form 10182. Id. 1. Prior to February 23, 2021, entitlement to a 60 percent rating for CAD is denied. The Board notes that the Veteran has been in continuous pursuit of this claim since September 3, 2019, which .F.R. § 3.2500(c). If an AMA claim is continuously pursued, it will be considered filed as of the date of the first claim in the continuously pursued chain, not the date the most recent request for review was received. 38 C.F.R. § 3.2500(h). For decisions rendered after a Higher-Level Review by the AOJ, continuous pursuit can be established by filing either a supplemental claim or a VA Form 10182. Id. 1. Prior to February 23, 2021, entitlement to a 60 percent rating for CAD is denied. The Board notes that the Veteran has been in continuous pursuit of this claim since September 3, 2019, which is the date on which the Veteran was notified of VA's proposal to reduce his rating from 30 percent to 10 percent. In a December 2019 rating decision, the RO determined that reduction was not proper and continued the 30 percent rating for the Veteran's CAD. He was notified of this decision in a letter dated December 11, 2019. In August 2020, the Veteran filed a VA Form 20-0995, Decision Review Request: Supplemental Claim, on which he identified the CAD issue and cited the December 11, 2019, notification letter. Because this supplemental claim was submitted within one year of the December 2019 CAD rating decision, the issue concerning the appropriate rating for the Veteran's CAD remained open. In December 2020, the RO issued a rating decision that continued the Veteran's 30 percent rating for CAD. He was notified of this decision in a letter dated December 17, 2020. On March 12, 2021, the Veteran submitted a VA Form 20-0995, Decision Review Request: Supplemental Claim, in which he cited the CAD claim and the prior decision date of December 17, 2020. Because this supplemental claim was submitted within one year of the December 2020 CAD rating decision, the issue concerning the appropriate rating for the Veteran's CAD remained open. The March 16, 2021, rating decision increased the CAD rating from 30 percent to 60 percent effective February 23, 2021. This effective date was assigned based on "the date [of] the Pharmacological Nuclear Stress Test ... because you continuously pursued your clam." The Veteran was notified of this decision in a letter dated March 17, 2021. The October 29, 2021, VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement), listed the CAD claim and cited the March 17, 2021, rating decision notification letter. In a January 25, 2022, statement, the Veteran's then-representative specified that the Veteran was requesting an earlier effective date for the grant of the increased, 60 percent rating. Given the Veteran's continuous pursuit of this claim, the Board will consider whether a 60 percent rating is warranted as early as September 3, 2019. Effective November 14, 2021, VA amended the rating criteria for arteriosclerotic heart disease (coronary artery disease) under 38 C.F.R. § 4.104, Diagnostic Code 7005. 86 Fed. Reg. 54089 (Sep. 30, 2021). This amended regulation applies to all applications for benefits received by VA or that are pending before the agency of original jurisdiction on or after November 14, 2021. In the case at hand, the rating period closes prior to November 14, 2021. Therefore, only the pre-amendment rating criteria apply. Prior to November 14, 2021, under 38 C.F.R. § 4.104, Diagnostic Code 7005, for arteriosclerotic heart disease (coronary artery disease), a 10 percent rating is warranted where a workload of greater than 7.0 metabolic equivalents (METs) but not greater than 10.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; continuous medication is required. A 30 percent rating is warranted where a workload of greater than 5.0 METs but not greater than 7.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; there is cardiac hypertrophy or dilatation on electrocardiogram, echocardiogram, or X-ray. A 60 percent rating is warranted where there is more than one episode of acute congestive heart failure in the past year, or; a workload of greater than 3.0 METs but not greater than 5. 10.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; continuous medication is required. A 30 percent rating is warranted where a workload of greater than 5.0 METs but not greater than 7.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; there is cardiac hypertrophy or dilatation on electrocardiogram, echocardiogram, or X-ray. A 60 percent rating is warranted where there is more than one episode of acute congestive heart failure in the past year, or; a workload of greater than 3.0 METs but not greater than 5.0 METs results in dyspnea, fatigue, angina, dizziness, or syncope, or; left ventricular dysfunction with an ejection fraction of 30 to 50 percent. A 100 percent rating is warranted where there is chronic congestive heart failure, or; a workload of 3.0 METs or less results in dyspnea, fatigue, angina, dizziness, or syncope, or; left ventricular dysfunction with an ejection fraction of less than 30 percent. Under the pre-amendment rating criteria, one MET is the energy cost of standing quietly at rest and represents an oxygen uptake of 3.5 milliliters per kilogram of body weight per minute. 38 C.F.R. § 4.104, Note (2). When the level of METs at which dyspnea, fatigue, angina, dizziness, or syncope develops is required for evaluation, and a laboratory determination of METs by exercise testing cannot be done for medical reasons, an estimation by a medical examiner of the level of activity (expressed in METs and supported by specific examples, such as slow stair climbing or shoveling snow) that results in dyspnea, fatigue, angina, dizziness, or syncope may be used. Id. For the purposes of a 60 percent evaluation, the pre-amendment rating criteria do not require a separate showing of left ventricular dysfunction in addition to an ejection fraction of 30 to 50 percent. Otero-Castro v. Principi, 16 Vet. App. 375, 382 (2002). Additionally, the phrase "30 to 50 percent" means 30 percent through 50 percent. Id. at 380. For the purposes of a 100 percent evaluation, the pre-amendment rating criteria do not require a separate showing of left ventricular dysfunction in addition to an ejection fraction of less than 30 percent. See id. at 382. In an October 2019 statement written in response to the proposal to reduce his CAD rating from 30 percent to 10 percent, the Veteran disputed VA's assertion that he has had "5 years of sustained improvement" noting that "I cannot perform miniscule activities without having to discontinue because of low stamina and energy!". The Veteran underwent a VA heart conditions examination in April 2019 and underwent a Transthoracic Echocardiogram in May 2019. The resulting May 2019 examination report notes that the Veteran "still reports intermittent SOB [shortness of breath] and fatigue with some exertional activities even though he works out daily. He stated this SOB and fatigue can occur even without exertion. He is being [seen] by cardiology for monitoring and treatment." It was noted that the Veteran uses several medications to control his heart condition. The examiner noted that the Veteran does not have congestive heart failure. The report notes that the echocardiogram noted a left ventricular ejection fracture (LVEF) of 65 percent, and wall motion and wall thickness were normal. The echocardiogram report itself notes that "The left ventricular diastolic function is normal. LVEF is 65-70%." It was noted that a METs test had been performed in June 2015 and that his METs level had been 11.1. At the time of the April 2019 VA examination, it was noted that the METs testing could not be completed. Instead, an interview-based METs test was conducted, and it was estimated that the Veteran's METs level was greater than 7 METs to 10 METs. At that level, he reported experiencing dyspnea and fatigue. The Veteran's heart condition impacted his ability to work in that the "Veteran's dyspnea and fatigue with exertional activity such as climbing stairs quickly, moderate bicycling, sawing wood, jogging (6 mph) increases cardiac symptoms and these activities lead to poor tolerance for general physical work." that his METs level had been 11.1. At the time of the April 2019 VA examination, it was noted that the METs testing could not be completed. Instead, an interview-based METs test was conducted, and it was estimated that the Veteran's METs level was greater than 7 METs to 10 METs. At that level, he reported experiencing dyspnea and fatigue. The Veteran's heart condition impacted his ability to work in that the "Veteran's dyspnea and fatigue with exertional activity such as climbing stairs quickly, moderate bicycling, sawing wood, jogging (6 mph) increases cardiac symptoms and these activities lead to poor tolerance for general physical work." The Veteran had been retired, but it was estimated that the Veteran would have lost "2-4 weeks work time in the last 12 months." The examiner changed the Veteran's diagnosis from CAD to "s/p CABG with residuals." It was noted that the "Veteran had a triple bypass surgery (CABG) in May 2016." An October 2019 Treadmill ECG Stress Test notes that "The exercise duration was 3:54 minutes and achieved 5.6 METS." Ultimately, the test was terminated due to fatigue and dyspnea. A July 2020 stress test from a private treatment provider notes that the Veteran "exercised for 05 minutes and 42 seconds on a Bruce protocol achieving 7.00 METS." The post stress ejection fraction was 55 percent. The December 2020 VA heart conditions examination report notes that the "Veteran reports he had a stress test 7/28/20 and cardiac catheterization 8/11/20 where he had a stent placed and 2 balloon cuts." It was noted that "Since his last cardiac catheterization his chest pain has improved but his sob has increased." He described current symptoms of "Constant shortness of breath, even at rest, and occasional chest pain." It was noted that the Veteran does not have congestive heart failure. The examination report notes that the May 2019 echocardiogram noted a left ventricular ejection fracture (LVEF) of 65 percent, and wall motion and wall thickness were normal. It was noted that the Veteran underwent an exercise stress test in July 2020, with the results showing a METs level of 7. The Veteran also underwent an interview-based METs test in which the examiner estimated that the Veteran's METs level is greater than 5 to 7 METs, with dyspnea, fatigue, and angina. The examiner stated that "The Veteran's LVEF is the most objective reflection of the current cardiac status." It was noted that the Veteran's heart condition impacts his ability to work in that "Due to his coronary artery disease, coronary artery bypass graft, history of a myocardial infarction, PCI, first degree AV block, and stent and cutting balloon placement veteran can perform light activities or sedentary work only." The examiner noted that the Veteran is retired but estimated that he would have had "0-1 week work time lost in last 12 months." On February 23, 2021, the Veteran underwent a Pharmacological Nuclear Stress Test. The resulting report notes that "The exercise duration ... achieved 3.2 METS." In a January 2022 statement, the Veteran's then-representative stated that the Veteran "respectfully, asserts that he is entitled to a 60 percent evaluation for CAD effective October 7, 2019." Review of the Veteran's VA medical records does not reveal cardiac treatment that assigns a METs number, identifies left ventricular dysfunction, or assigns an LVEF percentage. Based on the above, the Board finds that the evidence does not establish that an effective date prior to February 23, 2021, is warranted for the Veteran's 60 percent CAD rating. The VA examination reports and private testing that is described above, dated as recently as December 2020, reflects findings that do not satisfy the 60 percent criteria. Specifically, these records contain METs results that are greater than 5.0 METs, note no left ventricular dysfunction, and note an LVEF that is greater than 50 percent. There is no factually-ascertainable point between the December 2020 VA examination report and the February 23, 2021, private testing that reflects the presence of left ventricular dysfunction or demonstrates that the METs or LVEF testing results would have satisfied the 60 percent numerical criteria. As noted above, caselaw requires the Board to take due consideration that the beneficial effects of medication are discounted unless such effects are otherwise as December 2020, reflects findings that do not satisfy the 60 percent criteria. Specifically, these records contain METs results that are greater than 5.0 METs, note no left ventricular dysfunction, and note an LVEF that is greater than 50 percent. There is no factually-ascertainable point between the December 2020 VA examination report and the February 23, 2021, private testing that reflects the presence of left ventricular dysfunction or demonstrates that the METs or LVEF testing results would have satisfied the 60 percent numerical criteria. As noted above, caselaw requires the Board to take due consideration that the beneficial effects of medication are discounted unless such effects are otherwise contemplated in a particular diagnostic code. See Ingram v. Collins, No. 23-1798, ___ Vet. App. ___ (2025). In the case at hand, the Veteran takes medication for his CAD. However, the rating criteria of Diagnostic Code 7005 expressly contemplate the ameliorative effects of medication. Specifically, a 10 percent rating is warranted under Diagnostic Code 7005 when continuous medication is required for control. Therefore, the Board need not consider the ameliorative effects of medication in rating the Veteran's CAD. In short, the Board finds that entitlement to an effective date prior to February 23, 2021, for the assignment of the 60 percent rating for the Veterans' CAD is not warranted. Accordingly, the evidence is persuasively against the claim. As there is not an approximate balance of positive and negative evidence, the benefit-of-the-doubt doctrine is not applicable, and the claim must be denied. See 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102. Service Connection Service connection is warranted where the evidence of record establishes that an injury or disease resulting in disability was incurred in the line of duty in the active military service or, if pre-existing such service, was aggravated thereby. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). Service connection may also be granted for any injury or disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease or injury was incurred in service. 38 C.F.R. § 3.303(d). To establish a right to compensation for a present disability, a veteran must show (1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship, or nexus, between the present disability and the disease or injury incurred or aggravated during service. Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). A disability that is proximately due to, or results from, a service-connected disease or injury shall be considered a part of the original condition. 38 C.F.R. § 3.310(a). Secondary service connection on the basis of aggravation is permitted. 38 C.F.R. § 3.310(b). Compensation is payable for that degree of aggravation of a non-service-connected disability caused by a service-connected disability. Allen v. Brown, 7 Vet. App. 439 (1995). 2. Entitlement to service connection for diabetes mellitus is granted. In his September 2019 Supplemental Claim, the Veteran contends that his diabetes mellitus is "secondary to coronary artery disease & hypertension." The December 2019 rating decision notes contains the Favorable Finding that the Veteran has been diagnosed with diabetes mellitus, type II. The Board notes that service connection is in effect for CAD and labile hypertension. (Service connection for hypertension was established in a January 1974 rating decision, while service connection for CAD was established in an August 2004 rating decision.) The Veteran underwent a VA examination in connection with this claim in October 2019. Based on review of the record and interview and examination of the Veteran, the examiner opined that the Veteran's diabetes mellitus is less likely than not proximately due to or the result of the Veteran's service connected CAD and labile hypertension. In her rationale, the examiner noted that the Veteran was diagnosed with diabetes in 1992. She described diabetes mellitus, CAD, and hypertension and noted that "The veteran's [service connected] CAD and labile HTN are not risk factors for developing diabetes. Diabetes is a risk factor for development of CAD and HTN." Along with the October 2021 notice of disagreement, the Veteran submitted an October 2021 opinion from a private physician who provided the following opinion Based on review of the record and interview and examination of the Veteran, the examiner opined that the Veteran's diabetes mellitus is less likely than not proximately due to or the result of the Veteran's service connected CAD and labile hypertension. In her rationale, the examiner noted that the Veteran was diagnosed with diabetes in 1992. She described diabetes mellitus, CAD, and hypertension and noted that "The veteran's [service connected] CAD and labile HTN are not risk factors for developing diabetes. Diabetes is a risk factor for development of CAD and HTN." Along with the October 2021 notice of disagreement, the Veteran submitted an October 2021 opinion from a private physician who provided the following opinion: The diabetes in this individual, from a medical standpoint, is somewhat unusual because there is no family history of such, which is usually expected in typical type II diabetes. This alone serves as a strong indicator that a non-genetic, non-familial factor or cause is present. One immediately evident factor is hypertension. To summarize an extensive array of scientific studies on diabetes and hypertension, a bi-directional causal relationship exists between the two disorders, creating strong, bidirectional correlation. The examiner then discussed causation: Regarding causation, specific mechanisms by which diabetes causes hypertension that have been identified thus far have included hypertension-induced microvascular inflammation worsening the severity of the diabetes overall. The inflammation affects the pancreas beta cells directly and reduced the ability of those cells to secrete insulin on demand, but it primarily contributes to causation of insulin resistance characteristic of type II diabetes by renin-angiotensin system activation that occurs in the hypertension, as well as through platelet aggregation and clotting factor activation by the hypertension with the end products of those processes worsening the severity of the diabetes, (DH3-DH6). Genetic studies have indicated that this dual direction causation and worsening may have the same common or unitary underlying genetic causes underlying both directions, but that does not change the interacting "feedback" causation that results, whereby diabetes worsens or causes the hypertension, and conversely, the hypertension causes or worsens the diabetes. This is what is reflected in statistical studies. The conclusion that emerges from the above considerations and medical studies is that hypertension, particularly if unstable or severe, has strong correlation with initial development and later severity of type II diabetes. Multiple causal routes for nexus have been defined in scientific studies. In this individual, the absence of family history further indicates non-familial, non-genetically determined causation of this type to be present. As a result, more likely than not, the individual's unstable hypertension, which originated in service, was a major originating cause of his diabetes and is a major cause of its current severity beyond what would have been expected otherwise in its natural history. The Board finds these opinions to be highly probative, as they were authored by medical professionals who possess the necessary education, training, or experience to provide competent medical evidence under 38 C.F.R. § 3.159(a)(1). See Cox v. Nicholson, 20 Vet. App. 563 (2007). The VA opinion was based on review of the record and interview and examination of the Veteran, while the private opinion was based on review of the record. Both opinions offer rationales that cite to the facts of the Veteran's case and pertinent medical principles. The Board can find no reason to favor one of these opinions over the other. The Board will therefore resolve reasonable doubt in favor of the Veteran and find that the Veteran's diabetes mellitus was caused by his service-connected labile hypertension. Therefore, entitlement to service connection for diabetes mellitus is granted. 3. Entitlement to service connection for left lower extremity diabetic peripheral neuropathy is granted. 4. Entitlement to service connection for right lower extremity diabetic peripheral neuropathy is granted. 5. Entitlement to service connection for erectile dysfunction is granted. The December 2019 rating decision contains the Favorable Findings that the Veteran has "been diagnosed with a disability. VA examination conducted on October 31, 2019 shows a diagnosis of diabetic peripheral neuropathy, left lower extremity," that he has "been diagnosed with a disability. VA examination conducted on October 31, 2019 shows a diagnosis of diabetic peripheral neuropathy, right lower extremity," and that he has been diagnosed with a disability. VA examination conducted on October 31, 2019 shows that you are diagnosed with erectile dysfunction." The October 2019 VA examiner found that the Veteran has "Diabetic peripheral neuropathy" as "recognized complications of DM [diabetes mellitus]." The examiner also found that the Veteran has "Erectile dysfunction" that is "at least as likely as not ... due to DM." The October 202 2019 shows a diagnosis of diabetic peripheral neuropathy, left lower extremity," that he has "been diagnosed with a disability. VA examination conducted on October 31, 2019 shows a diagnosis of diabetic peripheral neuropathy, right lower extremity," and that he has been diagnosed with a disability. VA examination conducted on October 31, 2019 shows that you are diagnosed with erectile dysfunction." The October 2019 VA examiner found that the Veteran has "Diabetic peripheral neuropathy" as "recognized complications of DM [diabetes mellitus]." The examiner also found that the Veteran has "Erectile dysfunction" that is "at least as likely as not ... due to DM." The October 2021 private medical opinion also found that the Veteran's diabetic peripheral neuropathy of the lower extremities and erectile dysfunction were caused by the Veteran's diabetes mellitus. Service connection has been granted for diabetes mellitus, above. The Board finds that the Veteran's diabetic peripheral neuropathy of the left lower extremity, diabetic peripheral neuropathy of the right lower extremity, and erectile dysfunction were caused by his service-connected diabetes mellitus. Therefore, the claims of entitlement to service connection for diabetic peripheral neuropathy of the left lower extremity, diabetic peripheral neuropathy of the right lower extremity, and erectile dysfunction are granted. 6. Entitlement to service connection for sleep disturbed breathing, to include sleep apnea, is granted. According to a January 2022 statement from the Veteran's then-representative, the Veteran contends that service connection for sleep apnea is warranted secondary to his service-connected hypertension. It cites the October 2021 private medical opinion that was discussed above in connection with the Veteran's diabetes mellitus claim. The January 2020 rating decision contains the Favorable Finding that the Veteran has "been diagnosed with a disability. VA contract exam dated 12-12-2019 shows a diagnosis of obstructive sleep apnea." (This Favorable Finding was again noted in the March 8, 2021, Higher-Level Review rating decision.) The October 2021 private physician's medical opinion determined that "The most appropriate diagnosis for the disturbance of breathing during sleep is sleep disturbed breathing, or SDB," and that "half or more of the causation of the combined total of apneas and hypopneas is central." He also notes that "The basic diagnosis for consideration is SDB, which optimally replaces, but also encompasses, the one used in the records of OSA [obstructive sleep apnea]." With respect to the secondary service connection aspect of this claim, service connection is in effect for the primary disability of labile hypertension. The December 2019 VA examination report contains an etiology opinion that weighs against the Veteran's claim. However, this opinion only provides an etiology opinion with respect to whether the Veteran's sleep apnea was due to his service-connected CAD. It does not address the question of a relationship between the Veteran's sleep apnea and his hypertension. The October 2021 private medical opinion contains a highly detailed discussion of the Veteran's medical history and of pertinent medical principles. Based on these factors, the physician opined that "When the data on the relationship of hypertension to causation of SDB are considered, and all other possible causes of the individual's SDB are analyzed, more likely than not his SDB is the result of his service-connected hypertension, mediated through resultant cerebrovascular damage from the hypertension." The Board finds this opinion to be highly probative, as it was authored by a physician who possesses the necessary education, training, or experience to provide competent medical evidence under 38 C.F.R. § 3.159(a)(1). See Cox v. Nicholson, 20 Vet. App. 563 (2007). The opinion is based on a review of the record and contains a thorough discussion of the facts of the Veteran's case and pertinent medical principles. There is no contradictory medical opinion. Accordingly, the Board finds that the criteria for entitlement to service connection for sleep disrupted breathing, to include sleep apnea, have been met. The benefit is granted. REASONS FOR REMAND 1. Entitlement to a TDIU is remanded. The current decision has granted service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, erectile dysfunction, and sleep disturbed breathing, to include sleep apnea. The Agency of Original Jurisdiction must assign disability ratings and effective dates for these disabilities. Thus, the TDIU claim must be remanded for adjudication following the assignment of disability ratings and effective dates for the service connection claims that have been granted above. The matters are REMANDED for the following action: 1. Assign disability ratings for the Veteran apnea, have been met. The benefit is granted. REASONS FOR REMAND 1. Entitlement to a TDIU is remanded. The current decision has granted service connection for diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, erectile dysfunction, and sleep disturbed breathing, to include sleep apnea. The Agency of Original Jurisdiction must assign disability ratings and effective dates for these disabilities. Thus, the TDIU claim must be remanded for adjudication following the assignment of disability ratings and effective dates for the service connection claims that have been granted above. The matters are REMANDED for the following action: 1. Assign disability ratings for the Veteran's diabetes mellitus, left lower extremity diabetic peripheral neuropathy, right lower extremity diabetic peripheral neuropathy, erectile dysfunction, and sleep disturbed breathing, to include sleep apnea. Then readjudicate the issue of entitlement to a TDIU. TANYA SMITH Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Elizabeth Jalley, Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.