Citation Nr: 21025668 Decision Date: 04/28/21 Archive Date: 04/28/21 DOCKET NO. 15-29 402 DATE: April 28, 2021 REMANDED Service connection for hypertension, to include as secondary to diabetes mellitus.   REASONS FOR REMAND The Veteran served on active duty from November 1969 to September 1971. He had additional service in the Army Reserve. The case is on appeal from a June 2012 rating decision. Most recently, in a February 2021 decision, the Board remanded the claim for further development. Service connection for hypertension, to include as secondary to diabetes mellitus. The Veteran contends that his hypertension was caused or aggravated by his service-connected diabetes mellitus. Alternatively, he asserts that the disorder is directly related to service, to include herbicide exposure. The Veteran’s service personnel records (SPRs) show that he served in Vietnam and, therefore, his exposure to herbicides is presumed. As noted, the claim for hypertension was remanded by the Board in February 2021 for further development, including a VA opinion to determine the nature and etiology of the Veteran’s hypertension. The Board directed the examiner to opine as to whether the Veteran’s hypertension is directly related to service, to include his exposure to herbicide agents, or alternatively, was proximately caused or aggravated by his service-connected diabetes mellitus. A February 2021 VA opinion was submitted in which the examiner opined the Veteran’s hypertension was not caused or aggravated by his service-connected diabetes mellitus. She stated most adults have no identifiable cause for high blood pressure and it tends to develop gradually over many years. She indicated the Veteran’s risk factors for diabetes mellitus include a history of obesity and tobacco use. She stated the more one weighs, the more blood one needs to supply oxygen and nutrients to the tissues and as the amount of blood flow through the blood vessels increases, so does the pressure on the arterial walls. She reported the chemicals in tobacco can damage the lining of the arterial walls and when the arteries narrow, it leaves less space for blood to flow, increasing the pressure. The physician opined there is no known pathophysiological mechanism in which diabetes causes hypertension and thus, his current hypertension is less likely than not proximately caused by his diabetes mellitus with diabetic nephropathy. With regard to secondary aggravation, the February 2021 examiner found the Veteran’s hypertension was not aggravated beyond its natural progression by his diabetes mellitus. She indicated the Veteran’s records show he is on two medications for his hypertension, a low-dose amlodipine 5 mg by mouth daily and losartan 100 mg by mouth daily. She stated based on such daily medication, as well as his medical records which show consistent blood pressure readings, the Veteran’s hypertension has remained relatively well-controlled over the years. As such, the examiner opined aggravation of the Veteran’s hypertension by his diabetes mellitus has not been exhibited. The Board notes the February 2021 VA examiner’s opinion also includes a discussion regarding the direct service connection theory of entitlement. She indicated the Veteran’s hypertension is not directly related to service, including his exposure to herbicides. She stated there is no known pathophysiological mechanism in which herbicide exposure causes hypertension, and hypertension is not one of the medical conditions presumptively caused by Agent Orange exposure. The Board finds the February 2021 medical opinion provided by a VA physician contained adequate rationale and persuasive evidence in determining the Veteran’s hypertension is not etiologically related to his service-connected diabetes mellitus. However, an addendum opinion is required from the February 2021 examiner with regard to the direct service connection theory of entitlement, including whether the Veteran’s hypertension is related to his in-service herbicide exposure. In November 2018, the National Academy of Sciences (NAS) published a study reflecting that there is now evidence of a positive association between hypertension and exposure to tactical herbicides rather than “limited or suggestive” evidence of an association which was offered previously. In light of this, the Board finds that an additional medical opinion is warranted which considers the November 2018 NAS study. The matters are REMANDED for the following action: Forward the claims file to the VA examiner who provided the February 2021 VA opinion to obtain an addendum opinion to address whether the Veteran’s hypertension is directly related to service, to include herbicide exposure. If this examiner is no longer available, forward the claims file to an appropriate medical profession for an addendum opinion. The examiner should opine as to whether it is at least as likely as not (50 percent or greater probability) that the Veteran’s hypertension had its onset during, or is otherwise related to, service, to include his exposure to herbicides. In answering this question, the examiner is asked to consider the November 2018 NAS study finding sufficient evidence of a positive association between hypertension and exposure to tactical herbicides. RYAN T. KESSEL Veterans Law Judge Board of Veterans’ Appeals Attorney for the Board B. Isaacs, 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.