Citation Nr: 21063879 Decision Date: 10/18/21 Archive Date: 10/18/21 DOCKET NO. 19-17 772 DATE: October 18, 2021 REMANDED Service connection for obstructive sleep apnea (OSA) as secondary to type II diabetes mellitus (DM II) is remanded. REASONS FOR REMAND The Veteran honorably served in the Navy from May 1965 to September 1973. This matter is before the Board of Veterans Appeals (Board) on appeal from a January 2019 rating decision. The Veteran testified at a July 2021 hearing before the undersigned Veterans Law Judge (VLJ) and a transcript is of record. The Veteran's contention is that his OSA diagnosis is proximately due to or aggravated by his service-connected DM II. Here, the Board finds that the October 2018 VA medical opinion addressing these contentions was inadequate. It is well established that medical opinions addressing a secondary service connection theory of entitlement must address the issue of causation and aggravation. See El-Amin v. Shinseki, 26 Vet. App. 136 (2012). Although the examiner provided an opinion as to proximate causation, he did not provide an opinion as to possible aggravation of OSA by service-connected DM II. The matters are REMANDED for the following action: 1. Associate any outstanding VA or private treatment records with the claims file. 2. Obtain an opinion from a physician or other qualified medical professional that opines as to the following: Whether it is at least as likely as not that the Veteran's OSA is aggravated by his service-connected DM II? *Note that aggravation means any incremental increase in disability in non-service-connected disabilities (i.e., any additional impairment of earning capacity) resulting from service-connected conditions). The examiner is asked to provide the underlying reasons for all opinions expressed and is reminded that the term "as likely as not" does not mean "within the realm of medical possibility," but rather that the evidence of record is so evenly divided that, in the examiner's expert opinion, it is as medically sound to find in favor of the proposition as against it. Jennifer White Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Kyle McKone 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 This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.