SLEEP APNEA SYNDROMES (OBSTRUCTIVE CENTRAL MIXED)

Summary

The Veteran, an Army veteran who served from June 1968 to November 1988, appeals the denial of service connection for obstructive sleep apnea, claimed as secondary to his service-connected diabetes mellitus. The Veteran argued that his diabetes, treated with oral hypoglycemic agents, led to weight gain, which in turn caused his obstructive sleep apnea. The earliest evidence of sleep apnea was a 2008 diagnosis, with no in-service complaints noted. The Veteran's service treatment records showed him entering service at 155 pounds and separating with no record of sleep apnea symptoms. Post-service, his weight increased to 220 pounds by 2008, coinciding with the sleep apnea diagnosis. Two VA examinations were conducted; the first in February 2017 opined a negative nexus for diabetes causing sleep apnea, stating it was less likely than not related and that diabetes does not cause obesity, though it noted obesity as a risk factor. The second VA examination in May 2025 provided negative nexus opinions for several conditions but did not address diabetes or obesity in relation to sleep apnea. The Board found both VA examinations inadequate for failing to address whether diabetes caused obesity, which then caused sleep apnea, and for not considering the medical literature submitted by the Veteran and his private examiner. The Board found a December 2025 private medical opinion highly probative, concluding that the metabolic effects of diabetes and its medications contributed to weight gain, making obesity an intermediate step in the development of sleep apnea. The Board granted service connection for obstructive sleep apnea secondary to diabetes mellitus.

Rationale

Service connection granted secondary to diabetes mellitus; VA examinations found inadequate for failing to address obesity as intermediate step; Private medical opinion found probative, establishing nexus via obesity

Full Decision Text

Citation Nr: A26035783
Decision Date: 04/16/26	Archive Date: 04/16/26

DOCKET NO. 251217-609371
DATE: April 16, 2026

ORDER

Entitlement to service connection for obstructive sleep apnea, as secondary to service-connected diabetes mellitus, is granted.

FINDINGS OF FACT

1. The Veteran's obstructive sleep apnea was not incurred during his military service, did not manifest within one year of separation of service, and is not otherwise etiologically related to active service.

2. The Veteran's obesity is an intermediate step between his obstructive sleep apnea and his service-connected diabetes mellitus.

CONCLUSION OF LAW

The criteria for entitlement to service connection for obstructive sleep apnea, secondary to service-connected diabetes mellitus, are met.  38 U.S.C. §§ 1110, 1131, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310.

REASONS AND BASES FOR FINDING AND CONCLUSION

The Veteran served on active duty in the U.S. Army from June 1968 to November 1988.

This matter comes before the Board of Veterans' Appeals (Board) on appeal from a September 2025 Department of Veterans Affairs (VA) Regional Office (RO) rating decision. Subsequently, the Veteran timely appealed the September 2025 rating decision to the Board on a VA Form 10182, Decision Review Request: Board Appeal (Notice of Disagreement) and requested the evidence submission docket. Based upon the Veteran's selection of the evidence submission docket, the Board may consider: (1) evidence in the record at the time of the September 2025 rating decision; and (2) evidence submitted by the Veteran or his representative within the 90-day period following the receipt of the Veteran's December 2025 VA Form 10182.   

If the Veteran would like the VA to consider any evidence that was submitted that the Board could not consider, the Veteran may file a Supplemental Claim (VA Form 20-0995) and submit or identify this evidence. 38 C.F.R. § 3.2501. If the evidence is new and relevant, VA will issue another decision on the earlier effective date claim, considering the new evidence in addition to the evidence previously considered. Id. Specific instructions for filing a Supplemental Claim are included with this decision.   

Service Connection

Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active military service.  38 U.S.C. § 1110; 38 C.F.R. § 3.303.  Generally, the evidence 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 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).  Service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service.  38 C.F.R. § 3.303(d).

Service connection may also be granted on a secondary basis for a disability that is due to or aggravated by a service-connected disease or injury.  Establishing service connection on a secondary basis requires that there is sufficient evidence to show that (1) a current disability exists and (2) the current disability was either (a) caused by or (b) aggravated by a service-connected disability.  Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc); see also Spicer v. McDonough, 61 F.4th 1360, 1364 (Fed. Cir. 2023) (invalidating the requirement of "proximate cause" and instead holding "but for" causation or aggravation is enough to show entitlement to secondary service connection).  A permanent worsening is not required, as secondary service connection is warranted for any incremental increase in disability or any additional impairment of earning capacity in non-service-connected disabilities resulting from service-connected conditions regardless of its permanence.  Ward v. Wilkie, 31 Vet. App. 233, 239 (2019).

1. Entitlement to service connection for sleep apnea to include as secondary to diabetes mellitus.

The Veteran contends that his service-connected diabetes mellitus contributed to the development of obesity and caused his obstructive sleep apnea.

Obesity is not considered a disease or disability for VA purposes and is not subject to service connection.  See Marcelino v.
ation or aggravation is enough to show entitlement to secondary service connection).  A permanent worsening is not required, as secondary service connection is warranted for any incremental increase in disability or any additional impairment of earning capacity in non-service-connected disabilities resulting from service-connected conditions regardless of its permanence.  Ward v. Wilkie, 31 Vet. App. 233, 239 (2019).

1. Entitlement to service connection for sleep apnea to include as secondary to diabetes mellitus.

The Veteran contends that his service-connected diabetes mellitus contributed to the development of obesity and caused his obstructive sleep apnea.

Obesity is not considered a disease or disability for VA purposes and is not subject to service connection.  See Marcelino v. Shulkin, 29 Vet. App. 155 (2018).  VA's Office of General Counsel (OGC) issued a precedential opinion addressing questions regarding whether obesity may be considered a disease for the purposes of service connection under 38 U.S.C. §§ 1110 and 1131, and whether obesity may be considered a disability for purposes of secondary service connection.  In general, VAOPGCPREC 1-2017 concludes that obesity per se is not a disease or injury for purposes of 38 U.S.C. §§ 1110 and 1131 and, therefore, may not be service connected on a direct or secondary basis.  The opinion further noted that obesity may be an intermediate step between a service-connected disability and a current disability that may be connected on a secondary basis.  To meet this criterion, the Veteran must demonstrate that a previously service-connected disability caused the Veteran to become obese; that obesity was a substantial factor in causing secondary disability; and the secondary disability would not have occurred but for the obesity.  VAOPGCPREC 1-2017 (January 6, 2017).

Turning to the evidence of record, the Veteran's service treatment records (STRs) demonstrate that the Veteran weighed 155 pounds upon entrance. Military records are silent for complaints or symptoms of sleep apnea during service.

Post service private treatment records reflect a diagnostic sleep study with a diagnosis of severe obstructive sleep apnea in 2008. At that time, his weight had increased to 220 pounds, which the Veteran attributes to taking oral hypoglycemic agents for his diabetes mellitus, in particular pioglitazone, which is known to have weight gain as a possible side effect. The Veteran also submitted several medical articles discussing the interrelationship between diabetes mellitus and sleep apnea.

The Veteran was afforded a VA examination for sleep apnea in February 2017. The examiner noted the diagnosis of sleep apnea in 2008. The examiner opined a negative secondary nexus opinion for diabetes mellitus, saying that it was less likely than not that the diabetes mellitus was the cause of the Veteran's sleep apnea. Interestingly, the examiner did state that the Veteran's sleep apnea was due to his obesity and then stated that diabetes mellitus does not cause obesity. No other rationale was given. Also, no aggravation opinion was offered.

During a May 2025 VA examination, the examiner noted the Veteran's report that the symptoms started in about 2008, followed by the diagnosis of obstructive sleep apnea by sleep study. The VA examiner opined negative nexus opinions for secondary causation by hypertension, tinnitus, chronic renal disease, and toxic exposures, although the examiner was not asked for a secondary causation opinion for diabetes mellitus and did not opine on the role of obesity in this setting. As rationale, the examiner gave a brief description of the pathophysiology of sleep apnea followed by a list of risk factors for developing sleep apnea.

In support of his claim, the Veteran submitted a December 2025 private medical opinion by a PA, who opined that the Veteran's sleep apnea is due to his diabetes mellitus, because the disease affected the Veteran's exercise tolerance, stamina, and activity levels, resulting in the Veteran's weight gain. Likewise, he opined that the treatment of the diabetes mellitus with oral hypoglycemics contributed to the Veteran's weight gain. As support he presented multiple medical articles and summarized in detail that obesity may be an intermediate step between the Veteran's service-connected disability and the current disability.

Analysis

At the outset, the Veteran does not claim, nor does the record reflect, that he had any symptoms related to sleep apnea during, or on an ongoing basis, since service. The earliest relevant medical evidence of record indicating the presence of sleep apnea is in 2008, many years after separation from active service.  Moreover, there is no competent evidence of record indicating that the Veteran's sleep apnea was due to active service.

However, the Veteran and his representative assert that his sleep apnea is not directly related to his active duty service
 to the Veteran's weight gain. As support he presented multiple medical articles and summarized in detail that obesity may be an intermediate step between the Veteran's service-connected disability and the current disability.

Analysis

At the outset, the Veteran does not claim, nor does the record reflect, that he had any symptoms related to sleep apnea during, or on an ongoing basis, since service. The earliest relevant medical evidence of record indicating the presence of sleep apnea is in 2008, many years after separation from active service.  Moreover, there is no competent evidence of record indicating that the Veteran's sleep apnea was due to active service.

However, the Veteran and his representative assert that his sleep apnea is not directly related to his active duty service, but that his service-connected diabetes contributed to the development of obesity, which caused his sleep apnea.

Upon review of the relevant evidence, the Board determines that service connection for obstructive sleep apnea, secondary to the Veteran's service-connected diabetes, is warranted.  While VA examiners provided negative nexus opinions in February 2017 and May 2025, the Board finds them to be inadequate, as they do not address whether the Veteran's service-connected diabetes caused the Veteran to become obese, and that the Veteran's sleep apnea would not have occurred but for this obesity.  While the February 2017 VA examiner states that a risk factor of developing obstructive sleep apnea is excess weight, and he acknowledged the Veteran's high BMI, he only noted that his opinion is that diabetes does not cause obesity, rather than provide an opinion as to whether the Veteran's obesity is an intermediate step between his obstructive sleep apnea and his service-connected diabetes. Likewise, the VA examiners did not address the medical literature brought up by both the Veteran and by his private medical opinion. As such, the VA examinations are considered to have low probative value.

The Board finds the December 2025 medical opinion from a private examiner to be highly probative and sufficient to establish service connection for the Veteran's obstructive sleep apnea, as it is competent, credible, and probative, and it is based on a review of the Veteran's claims file and is supported by medical literature and consideration of the Veteran's lay statements.  The private examiner determined that the metabolic effects of the diabetes and side effects of the medications used to treat it prevented the Veteran from being able to exercise and contributed to his weight gain after separation from service, and that his obesity played an intermediate step in the development of his obstructive sleep apnea.  Thus, a nexus is established.

In conclusion, as the Board finds that the Veteran's obesity is an intermediate step between his obstructive sleep apnea and his service-connected diabetes, his claim for service connection for obstructive sleep apnea is granted.

 

 

Thomas L. English

Veterans Law Judge

Board of Veterans' Appeals

Attorney for the Board	Seibert, Andrew L. II

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 applic the examiner stated ability. 38 C.F.R. § 20.1303.