Citation Nr: 21025695 Decision Date: 04/28/21 Archive Date: 04/28/21 DOCKET NO. 15-32 832 DATE: April 28, 2021 ORDER Entitlement to service connection for diabetes mellitus, to include as secondary to service-connected disabilities, is granted. FINDING OF FACT The probative evidence of record is at least in relative equipoise that the Veteran’s diabetes is related to his service-connected sleep apnea. CONCLUSION OF LAW The criteria for service connection diabetes mellitus have been met. 38 U.S.C. §§ 1110, 1154; 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.310. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty in the United States Air Force from September 1976 to September 1980. In October 2018, the Veteran was provided a hearing with the undersigned Veterans Law Judge and a transcript of the proceeding is of record. The claim was brought before the Board in April 2019 and was remanded for further development. Service Connection Service connection will be granted if the evidence demonstrates that a current disability resulted from an injury or disease incurred in or aggravated by active service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). In order to establish service connection, the record must show competent evidence of three things: (1) a current disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship, i.e., a nexus, between the claimed in-service disease or injury and the current disability. Holton v. Shinseki, 557 F.3d, 1362, 1366 (Fed. Cir. 2009). When considering such a claim for service connection, the Board must consider on a case-by-case basis, the competence and sufficiency of lay evidence offered to support a finding of service connection. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009) (quoting Jandreau v. Nicholson, 492 F.3d 1372, 1377 Fed. Cir. 2007)).  The mere conclusory or generalized lay statements that a service event or illness caused a current disability are insufficient. Waters v. Shinseki, 601 F.3d 1274, 1278 (2010).  Entitlement to Service Connection: Diabetes Mellitus: The Veteran contends that his diabetes is related to his active duty service, to include as secondary to his service-connected disabilities. Service connection on a secondary basis essentially requires evidence sufficient to show: (1) that a current disability exists; and (2) that the current disability was either caused or aggravated by a service-connected disability. 38 C.F.R. § 3.310. Additionally, obesity may be considered as an intermediate step in a causal chain for service connection that can be established on either a causal or aggravation basis. See Walsh v. Wilkie, 32 Vet. App. 300, 306-307 (2020). In October 2020, the Veteran provided an August 2020 private opinion. The physician opined that there is substantial evidence that sleep apnea has both caused and aggravated multiple health conditions in the Veteran, to include diabetes. The physician explained that that medical literature supports a conclusion that by some means, sleep apnea induces metabolic derangements that produce underlying pathophysiologic abnormalities of insulin resistance and impaired glucose tolerance. The physician provided that while doing so, the physiological responses to this insulin resistance and impaired glucose tolerance may, and often does, lead to hyperinsulinemia in response to the insulin resistance with associated weight gain due to the fat storage effects of insulin. The physician additionally explained that weight increases and aggravates sleep apnea, which further aggravates insulin resistance and glucose intolerance with eventual development of type 2 diabetes. The physician noted that once the insulin resistance state begins, it triggers a pernicious cycle of weight gain due to hyperinsulinemia, which further aggravates insulin resistance. The physician clarified that while it is unknown when the cycle began in the Veteran, the probable duration of his sleep apnea had likely started well before his diagnosis of diabetes, and noted that the Veteran was likely in a pre-diabetic state for months to years, which is not unusual for diabetes type 2. The physician lastly addressed the notion that the Veteran’s weight gain is largely associated with his diabetes, noting that although early understanding of type 2 diabetes taught that obesity occurred and brought type 2 diabetes, current understanding of the condition has found that type 2 diabetes occurs in non-obese people as well. The physician further noted that the current concept of the origin of type 2 diabetes is that insulin resistance begins at some unknowable point in time and causes metabolic processes that encourages weight gain despite any obvious dietary indiscretion. Thus, weight gain is often rather slow and by the time type 2 diabetes is fully manifested, the obesity is already present and often blamed for the condition. In October 2020, the Veteran provided another September 2020 opinion from a private physician. The physician opined that there is a greater than 50 percent chance that the Veteran’s diabetes is caused by or significantly more severe as a result of his obstructive sleep apnea. The examiner rationalized that medical literature notes there is a strong association between sleep apnea and diabetes, but also strong evidence of causation. The physician further stated that there is even some evidence that aspects of glucose metabolism can be partially reversed when sleep apnea is effectively treated with CPAP for sufficient time. The physician explained that the available evidence spans from epidemiologic studies to those evaluating the effect of specific physiologic perturbations of sleep apnea on diabetes/glucose metabolism. The physician noted that one study, performed at the University of Chicago, has been cited extensively in medical literature following publication in the highest rated journal in critical care medicine, and it found that HbA1c increased by an average of 1.49 percent, 1.38 percent, and 3.69 percent, respectively in patients with mild, moderate, and severe sleep apnea after adjusting for age, gender, BMI, race, number of antidiabetic mediations, exercise, duration of diabetes, and total sleep time compared with patients without sleep apnea. The physician lastly noted that the authors of the study concluded that in type 2 diabetes patients, “increasing severity of obstructive sleep apnea is associated with poorer glucose control independent of adiposity and other confounders, with effect sizes comparable to those of widely used hypoglycemic drugs.” The Board recognizes that a February 2020 examiner found that the Veteran’s diabetes was not related to his service, or to his service-connected disabilities. However, in applying the benefit of the doubt in favor of the Veteran, the Board finds that the evidence is in relative equipoise that the Veteran’s diabetes is related to his service-connected sleep apnea. Therefore, the Board finds August 2020 and September 2020 private opinions to be of significant probative value in determining the Veteran’s diabetes is related to his service-connected disabilities, to include obesity as an intermediate step.  The Board notes that the probative value of medical opinion evidence is based on the medical experts’ personal examination of the patient, their knowledge, and skill in analyzing the data, and their medical conclusion.  As is true with any piece of evidence, the credibility and weight to be attached to these opinions are within the province of the adjudicator.  Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993).  Here, the private physicians’ showed knowledge of the Veteran’s background and based the opinions on the Veteran’s lay contentions, the physician’s medical knowledge, review of his records, as well as a review of medical literature. Additionally, the physicians provided complete and thorough rationales for the opinions rendered and are consistent with the medical evidence of record.  See Guerrieri v. Brown, 4 Vet. App. 467, 470-71 (1993).  Therefore, the Board concludes that the probative evidence of record is for the claim and the benefit of the doubt doctrine has been applied. See Gilbert v. Derwinski, 1 Vet. App. 49 (1990); Ortiz v. Principi, 274 F.3d 1361 (Fed Cir. 2001). JENNIFER HWA Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board J. Negron, 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.