Citation Nr: 1312563 Decision Date: 04/16/13 Archive Date: 05/02/13 DOCKET NO. 07-06 535A ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in New Orleans, Louisiana THE ISSUE Entitlement to service connection for hypertension, to include as due to herbicide exposure and/or as secondary to service-connected diabetes mellitus. REPRESENTATION Veteran represented by: The American Legion ATTORNEY FOR THE BOARD April Maddox, Counsel INTRODUCTION The Veteran served on active duty from November 1965 to November 1967. This matter comes before the Board of Veterans' Appeals (Board) on appeal from August 2005 and May 2009 rating decisions issued by the Department of Veterans Affairs (VA) Regional Office (RO) in New Orleans, Louisiana. Specifically, the August 2005 rating decision denied service connection for hypertension as secondary to herbicide exposure. The May 2009 rating decision denied service connection for hypertension as secondary to diabetes mellitus. The Veteran perfected appeals as to both decisions. In November 2010, the Board remanded the matter to the agency of original jurisdiction (AOJ) for additional development. As will be discussed herein, the Board finds that the AOJ substantially complied with the remand orders such that no further action is necessary in this regard. See D'Aries v. Peake, 22 Vet. App. 97, 105 (2008); Dyment v. West, 13 Vet. App. 141, 146-47 (1999) (remand not required under Stegall v. West, 11 Vet. App. 268 (1998), where the Board's remand instructions were substantially complied with), aff'd, Dyment v. Principi, 287 F.3d 1377 (2002). Most recently, in January 2013, the case was referred to the Veterans Health Administration (VHA) for an expert medical opinion. An opinion was obtained and in February 2013 a copy of this opinion was sent to the Veteran and his representative. The Board notes that, in addition to the paper claims file, there is a Virtual VA paperless claims file. A review of the documents in such file reveals VA treatment records dated from December 2010 through November 2011 which were considered by the AOJ in the most recent December 2011 supplemental statement of the case. The remainder of the documents in the file are either duplicative of the evidence in the paper claims file or are irrelevant to the issue on appeal. FINDINGS OF FACT 1. The Veteran served in the Republic of Vietnam during the Vietnam Era. 2. Hypertension is not related to any disease, injury, or incident of service, did not manifest within one year of service discharge, and was not caused or aggravated by a service-connected disability. CONCLUSION OF LAW Hypertension was not incurred in or aggravated by the Veteran's active duty military service, may not be presumed to have been incurred in or aggravated by such service, and is not proximately due to or the result of a service-connected disability. 38 U.S.C.A. §§ 1110, 1112, 1113, 1131, 5103, 5103A, 5107 (West 2002); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309, 3.310 (2006), (2012). REASONS AND BASES FOR FINDINGS AND CONCLUSION I. VA's Duties to Notify and Assist The Veterans Claims Assistance Act of 2000 (VCAA) and implementing regulations impose obligations on VA to provide claimants with notice and assistance. 38 U.S.C.A. §§ 5102, 5103, 5103A, 5107 (West 2002 & Supp. 2012); 38 C.F.R §§ 3.102, 3.156(a), 3.159, 3.326(a) (2012). Proper VCAA notice must inform the claimant of any information and evidence not of record (1) that is necessary to substantiate the claim; (2) that VA will seek to provide; and (3) that the claimant is expected to provide. 38 U.S.C.A. § 5103(a); 38 C.F.R. § 3.159(b)(1). In Dingess/Hartman v. Nicholson, 19 Vet. App. 473 (2006), the United States Court of Appeals for Veterans Claims (Court) held that the VCAA notice requirements of 38 U.S.C.A. § 5103(a) and 38 C.F.R. § 3.159(b) apply to all five elements of a service connection claim. Those five elements include: 1) Veteran status; 2) existence of a disability; 3) a connection between the Veteran's service and the disability; 4) degree of disability; and 5) effective date of the disability. In Pelegrini v. Principi, 18 Vet. App. 112 (2004), the Court held that a VCAA notice, as required by 38 U.S.C.A. § 5103(a), must be provided to a claimant before the initial unfavorable AOJ decision on the claim for VA benefits. In the instant case, the Board finds that VA has satisfied its duty to notify under the VCAA. Specifically, a May 2005 letter, sent prior to the initial August 2005 rating decision that denied the Veteran's claim on a direct and presumptive basis, advised the Veteran of the evidence and information necessary to substantiate his service connection claim on a direct and presumptive basis as well as his and VA's respective responsibilities in obtaining such evidence and information. Additionally, March 2007 and December 2008 letters, sent prior to the initial May 2009 rating decision that denied the Veteran's claim on a secondary basis, advised the Veteran of the evidence and information necessary to substantiate his service connection claim on a secondary basis as well as his and VA's respective responsibilities in obtaining such evidence and information. Additionally, the May 2007 and December 2008 letters advised him of the information and evidence necessary to establish a disability rating and an effective date in accordance with Dingess/Hartman, supra. To the extent that the timing of any notice is deficient, the United States Court of Appeals for the Federal Circuit has held that VA could cure such a timing problem by readjudicating the Veteran's claim following a compliant VCAA notification letter. Mayfield v. Nicholson, 444 F. 3d 1328, 1333-34 (Fed. Cir. 2006). The Court clarified that the issuance of a statement of the case could constitute a readjudication of the Veteran's claim. See Prickett v. Nicholson, 20 Vet. App. 370 (2006). In the instant case, after all of the VCAA letters were provided to the Veteran, his claim was readjudicated in June 2009 statements of the case, and July 2009 and December 2011 supplemental statements of the case. Therefore, any defect with respect to the timing of the VCAA notice has been cured. In addition, the duty to assist the Veteran has also been satisfied in this case. The Veteran's service treatment records as well as all identified and available post-service VA and private medical records are of record and were reviewed by both the RO and the Board in connection with the Veteran's claim. The Veteran has not identified any outstanding records that are pertinent to his appeal. He was also provided the opportunity to testify at a hearing before the Board although he declined to do so. The Veteran was afforded a VA examination in December 2010 with respect to the issue decided herein; however, as the examiner could not offer an opinion regarding whether the Veteran's hypertension was aggravated by a service-connected disability without resort to speculation, the Board referred the case to the Veterans Health Administration (VHA) for an expert medical opinion with respect to such aspect of his claim. The Board finds that the opinions of record are adequate to decide the issue as they are predicated on a review of the claims file, which includes the Veteran's statements, his service treatment records, and post-service treatment records. Additionally, the opinions proffered considered all of the pertinent evidence of record, to include the statements of the Veteran, and provided a complete rationale, relying on and citing to the records reviewed. Therefore, the Board finds that the opinions are adequate to decide the Veteran's case as the examiners offered clear conclusions with supporting data as well as a reasoned medical explanation connecting the two. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008); Stefl v. Nicholson, 21 Vet.App. 120, 124 (2007) ("[A]medical opinion ... must support its conclusion with an analysis that the Board can consider and weigh against contrary opinions"). In November 2010, the Board remanded the case for additional development, to include obtaining outstanding VA treatment records dated from July 2009 to the present and affording the Veteran a VA examination in order to determine the current nature and etiology of his hypertension, which was accomplished in December 2010. While the December 2010 VA examiner did not offer an adequate opinion, the February 2013 VHA opinion is adequate to decide the case. Therefore, the Board finds that the AOJ has substantially complied with the November 2010 remand directives such that no further action is necessary in this regard. See D'Aries, supra. Thus, the Board finds that VA has fully satisfied the duty to assist. In the circumstances of this case, additional efforts to assist or notify the Veteran in accordance with the VCAA would serve no useful purpose. See Soyini v. Derwinski, 1 Vet. App. 540, 546 (1991) (strict adherence to requirements of the law does not dictate an unquestioning, blind adherence in the face of overwhelming evidence in support of the result in a particular case; such adherence would result in unnecessarily imposing additional burdens on VA with no benefit flowing to the appellant); Sabonis v. Brown, 6 Vet. App. 426, 430 (1994) (remands which would only result in unnecessarily imposing additional burdens on VA with no benefit flowing to the appellant are to be avoided). VA has satisfied its duty to inform and assist the Veteran at every stage in this case, at least insofar as any errors committed were not harmful to the essential fairness of the proceeding. Therefore, he will not be prejudiced as a result of the Board proceeding to the merits of his claim. II. Analysis This appeal arises out of the Veteran's assertion that hypertension is related to his service with the United States Marine Corps from November 1965 to November 1967. Specifically, the Veteran argues that this condition is due to his presumed exposure to herbicides or as secondary to either his service-connected diabetes mellitus. Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by service. 38 U.S.C.A. § 1110; 38 C.F.R. § 3.303(a). Service connection may also be granted for any disease diagnosed after discharge, when all of the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). Direct service connection may not be granted without evidence of a current disability; in-service incurrence or aggravation of a disease or injury; and a nexus between the claimed in-service disease or injury and the present disease or injury. 38 U.S.C.A. § 1112; 38 C.F.R. § 3.304. See also Caluza v. Brown, 7 Vet. App. 498, 506 (1995) aff'd, 78 F.3d 604 (Fed. Cir. 1996) [(table)]. Additionally, for Veterans who have served 90 days or more of active service during a war period or after December 31, 1946, certain chronic disabilities, such as cardiovascular-renal disease, including hypertension, are presumed to have been incurred in service if manifest to a compensable degree within one year of discharge from service. 38 U.S.C.A. §§ 1101, 1112; 38 C.F.R. §§ 3.307, 3.309. Alternatively, when a disease at 38 C.F.R. § 3.309(a) is not shown to be chronic during service or the one year presumptive period, service connection may also be established by showing continuity of symptomatology after service. See 38 C.F.R. § 3.303(b). The use of continuity of symptoms to establish service connection is limited only to those diseases listed at 38 C.F.R. § 3.309(a). Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). Service connection may be established on a secondary basis for a disability which is proximately due to or the result of service-connected disease or injury. 38 C.F.R. § 3.310(a). Establishing service connection on a secondary basis requires evidence sufficient to show (1) that a current disability exists and (2) that the current disability was either (a) proximately caused by or (b) proximately aggravated by a service-connected disability. Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc). The Board notes that the provisions of 38 C.F.R. § 3.310 were amended during the pendency of the Veteran's appeal, effective October 10, 2006; however, the new provisions state that service connection may not be awarded on the basis of aggravation without establishing a pre-aggravation baseline level of disability and comparing it to the current level of disability. 38 C.F.R. § 3.310(b). Although the stated intent of the change was merely to implement the requirements of Allen, supra, the Board finds that the new provisions amount to a substantive change to the manner in which 38 C.F.R. § 3.310 has been applied by VA in Allen-type cases since 1995. Consequently, the Board will apply the older version of 38 C.F.R. § 3.310, which is more favorable to the Veteran as it does not require the establishment of a baseline level of disability before an award of service connection may granted. See generally, Kuzma v. Principi, 341 F.3d 1327 (Fed. Cir. 2003); VAOPGCPREC 7-2003. VA regulations provide that a Veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the Vietnam era, namely from February 28, 1961, to May 7, 1975, shall be presumed to have been exposed during such service to an herbicide agent, unless there is affirmative evidence to establish that the Veteran was not exposed to any such agent during that service. 38 C.F.R. § 3.307(a)(6)(iii). The Board notes that the Veteran's service personnel records reflect service in Vietnam during the relevant time period. As such, the Board finds that the Veteran is presumed to have been exposed to herbicides coincident with service in the Republic of Vietnam. If a Veteran was exposed to an herbicide agent during active service, presumptive service connection is warranted for numerous disorders; however, hypertension is not included on such list. 38 C.F.R. § 3.309(e), as amended, 75 Fed. Reg. 53,203 (August 31, 2010). In this regard, VA's Secretary has determined that a presumption of service connection based on exposure to herbicides used in the Republic of Vietnam during the Vietnam era is not warranted for any condition for which the Secretary has not specifically determined a presumption of service connection is warranted. See 68 Fed. Reg. 27,630 (May 20, 2003). Lay testimony is competent to establish the presence of observable symptomatology and "may provide sufficient support for a claim of service connection." Layno v. Brown, 6 Vet. App. 465, 469 (1994). When a condition may be diagnosed by its unique and readily identifiable features, the presence of the disorder is not a determination "medical in nature" and is capable of lay observation. In such cases, the Board is within its province to weigh that testimony and to make a credibility determination as to whether that evidence supports a finding of service incurrence and continuity of symptomatology sufficient to establish service connection. See Barr v. Nicholson, 21 Vet. App. 303 (2007). Lay evidence can be competent and sufficient to establish a diagnosis of a condition when (1) a layperson is competent to identify the medical condition, (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant. 38 U.S.C.A. § 5107; 38 C.F.R. § 3.102; see also Gilbert v. Derwinski, 1 Vet. App. 49 (1990). The Veteran's service treatment records are negative for hypertension during service. Examination reports prior to and during service show the following blood pressure readings: 118/84 (February 1965), 120/80 (November 1965), and 132/80 (November 1967). These reports also show a normal heart. Additionally, there is no evidence of hypertension within one year after service. The earliest treatment records in the claims file are dated in September 2003. These records show a history of both diabetes and hypertension. During an August 2005 VA examination the reported that he had first been diagnosed with diabetes in the 1980's. Moreover, as discussed herein, the VA examiners place the onset of hypertension in 1972 at the earliest. Pursuant to the November 2010 Board remand, the Veteran was afforded a VA hypertension examination in December 2010. During this examination the Veteran reported that he was first diagnosed with hypertension during an insurance physical sometime between 1972 and 1975 and that the diagnosis was confirmed at that time by his family physician. He was begun on medication for hypertension at that time and had continued on medication since that time. The Veteran felt that he was taking more medication and higher doses now to control his hypertension now than he did at the onset. The examiner indicated that the first recorded glucose reading in VA treatment records is dated in October 2005 which indicated the presence of diabetes. No prior glucose readings were available so the examiner did not know for sure when the diabetes began but indicated that diabetes was obviously present in October 2005. The examiner also stated that the Veteran was first found to have stage two diabetic nephropathy in April 2008. According to the Veteran's history, he was first diagnosed with hypertension sometime between 1972 and 1975. The examiner indicated that, for diabetes to be the cause of hypertension, there must be the presence of diabetic nephropathy. In the Veteran's case, the hypertension was found five to eight years after his discharge from military service. Thus, the Veteran did not have hypertension during his military service. The earliest evidence of diabetic nephropathy is April 2008. Prior to that date testing in October 2005 was negative for diabetic nephropathy. Thus, the first appearance of diabetic nephropathy was 33 to 36 years after the onset of hypertension in the period from 1972 to 1975. Thus, the examiner opined that, on the basis of the above rationale, hypertension onset was five to eight years after release from military service and was 33 to 36 years prior to the appearance of diabetic nephropathy. Thus, the onset of hypertension is after release from service and is many years prior to the presence of diabetic nephropathy. It therefore did not originate in service, is not due to the Veteran's service-connected diabetes, and is not etiologically related to the Veteran's military service. With regard to whether the hypertension is aggravated by the Veteran's service-connected diabetes mellitus the examiner wrote that he would have to resort to mere speculation to resolve this question. In the February 2013 VHA opinion, the examiner (a nephrologist) was asked if it was at least as likely as not that the Veteran's hypertension was aggravated (i.e., permanently increased in severity beyond the natural progress of the disease) by his diabetes mellitus. The examiner was also asked to discuss the impact the Veteran's diabetic nephropathy had on his hypertension, if any, and his contention that he had to increase his medication for hypertension since his diabetes diagnosis. The examiner noted that the Veteran had a history of hypertension, type 2 diabetes mellitus, nephrolithiasis, hyperlipidemia, osteoarthritis, gout, and posttraumatic stress disorder. He also had a history of nephrolithiasis and hypogonadism. The Veteran was on active duty in the military from November 1965 to November 1967. During this time period, he served in Vietnam and was exposed to herbicides. The Veteran was service connected for diabetes mellitus, ostensibly as a result of his herbicide exposure, as well as neuropathy and erectile dysfunction as a result of his service-connected diabetes. The examiner noted that a review of the Veteran's medical records indicated that the Veteran received a diagnosis of hypertension in the early to mid-1970s during an insurance physical examination. It was more difficult to determine the date of onset of his type 2 diabetes mellitus, but he was being treated with a medication for diabetes (glipizide) in November 2003 and glucose levels from August 2005 were reportedly elevated at 166 mg/dl. Moreover, a urinalysis from October 2005 revealed glucose in his urine, which was slightly suggestive of diabetes mellitus. Because the medical records prior to this time were scant, it was difficult to know with certainty, but, taken together, the examiner noted that the data was consistent with an onset of diabetes mellitus in the early 2000s, some 25 years after his diagnosis of hypertension. The examiner indicated that he was asked to review the available medical records to determine the role his service-connected diabetes mellitus had in aggravating the Veteran's high blood pressure control as well as comment on the potential impact of diabetic nephropathy on hypertension. Based on these issues, the examiner indicated that the pertinent questions were: 1) Can the development of diabetes mellitus aggravate blood pressure control?, 2) What is the role of diabetic nephropathy in worsening systemic hypertension?, and 3) Is there evidence that the Veteran's blood pressure was more difficult to control after the development of diabetes mellitus which, in turn, would be consistent with the notion that diabetes aggravated the Veteran's hypertension? With regard to the first two questions, the examiner noted that there was strong experimental evidence that diabetes mellitus might promote the development of high blood pressure. In this regard, the endothelium produces substances that "relax" blood vessels and decreases systemic blood pressure under normal conditions. Diabetes mellitus promotes endothelial dysfunction and decreases generation of these vasodilator substances. One of the best characterized of these vessel relaxing agents is nitric oxide (NO), and there is strong experimental evidence in humans and animal models that production of NO is decreased in diabetes. In animals, inhibition of NO generation either pharmacologically or by genetic manipulations causes a large increase in systemic blood pressure. While it is difficult to prove, it is, therefore, possible that diabetes might aggravate blood pressure control, even in the absence of other diabetic complications (for a review of this topic see Nat Rev Nephrol 7:36, 2011). Complications of diabetes mellitus may further impair blood pressure regulation. In this regard, the development of diabetic nephropathy is a particularly severe complication of diabetes mellitus and is frequently associated with evidence of endothelial dysfunction as well as the development of hypertension. The elevated blood pressure in diabetic nephropathy is likely the result of both endothelial dysfunction as well as salt and water retention as the disease progresses. Endothelial dysfunction is associated with the development of microvascular complication so diabetes, which includes neuropathy, retinopathy, and nephropathy. With regard to these complications, the Veteran is currently service-connected for neuropathy and review of his medical records indicates non-proliferative diabetic retinopathy by an eye examination in October 2008. He, therefore, also had diabetic eye disease. Based on the available data, however, it was difficult for the examiner to make a diagnosis of diabetic nephropathy in the Veteran. In the absence of a kidney biopsy, the diagnosis of diabetic nephropathy was supported by the following criteria: 1) Diabetes of sufficient duration to develop the complication (10 years in type 1 diabetes but may be somewhat less in type 2 diabetes due to the difficulty in establishing the exact onset of the disease), 2) The associated between diabetic kidney disease and the development of diabetic retinopathy, and 3) The development of large amounts of protein in the urine termed macroalbuminuria (more than trace ,which can often be seen in normals with a concentrated urine). As the nephropathy progresses, the disease process is associated with a loss of the kidney's ability to filter the blood (usually detected by an increase in serum creatinine or a decrease in glomerular filtration rate [GFR]). By the examiner's review of the available data, the Veteran met at least two of the criteria for the development of diabetic kidney disease (retinopathy and sufficient duration of diabetes). The data available with regard to the Veteran's proteinuria was limited but included the following urinalysis records: 1) Negative urine protein in October 2005, 2) Trace urine protein with a highly concentrated urine in April and September 2008, and 3) Trace urine protein recorded in the medical records with no measurement of urine concentration. Consistent with low levels of proteinuria during this time period, the Veteran had urinary albumin levels within the normal reference range for this laboratory of 4.5, 4.8, and 6.9 milligrams (mg) albumin/gram creatinine in 2005, 2007, and 2008, respectively. He also had little evidence of significant deterioration in his renal function as of 2010 with serum creatinine values in the 0.9 to 1.1 mg/dl range and an estimated GFR (eGFR) of 90.7 ml/min. The examiner indicated that it would be helpful to have additional information to determine if the Veteran had developed evidence of significant proteinuria in the last one to two years but, based on the available data, the examiner could not make a diagnosis of diabetic kidney disease in the Veteran, although he was clearly at high risk for the development of this complication. To determine if there was evidence that the Veteran's blood pressure was more difficult to control after the development of diabetes (question #3), the examiner reviewed the available records for: 1) blood pressure measurements during clinic visits, 2) changes in his blood pressure medications, and 3) the development of the hypertension related complication left ventricular hypertrophy. This review revealed: 1) excellent blood pressure control in the 102-136/66-76 range since 2005, and 2) no evidence of left ventricular hypertrophy given an echocardiogram revealing normal contractility and normal ventricular wall thickness in December 2010. The Veteran's anti-hypertensive medications were changed from 12.5 mg hydrochlorothiazide (HCTZ) and 10 mg lisinopril to 25 mg HCTV and 40 mg valsartan because of a complication related to lisinopril treatment (cough). The examiner noted that blood pressure control did not currently appear to be problematic and the examiner could not link the increase in HCTV dosage to poor controlled blood pressure. Thus, the examiner could find no evidence that the Veteran's blood pressure was more difficult to control since the development of diabetes mellitus or evidence that the hypertension related complication left ventricular hypertrophy is associated with the poorly controlled blood pressure. In summary, the examiner found that the Veteran had several microvascular complications that were likely related to his diabetes mellitus including retinopathy and neuropathy. With the caveat that recent laboratory data was not available, the examiner could not make a diagnosis of diabetic nephropathy in the Veteran, although he was at high risk for the development of this serious complication. Lastly, while diabetes has the potential to worsen blood pressure control, based on the available medical records, the examiner found no evidence that the Veteran's diabetes mellitus aggravated the Veteran's blood pressure control based on review of the recorded blood pressure measurements, changes in his medical regimen, or evidence of blood pressure related end-organ damage. The Board finds that the preponderance of the evidence is against service connection for hypertension on a presumptive basis. First, there is no evidence of hypertension within one year after the Veteran's discharge. In this regard, the absolute earliest that the VA examiners and the Veteran himself place the onset of hypertension is in 1972, which is five years after his service discharge. Moreover, the Veteran has not alleged a continuity of hypertension symptomatology between the time of his discharge and the diagnosis of such disease. See Walker, supra. Therefore, service connection based on the manifestation of a chronic presumptive disease within one year of service discharge is not warranted. Second, presumptive service connection based on exposure to herbicides is also not warranted. In this regard, while the Veteran served in the Republic of Vietnam during the Vietnam War and is therefore presumed to have been exposed to herbicides during service, hypertension is not a disease for which a presumption based on herbicide exposure is warranted under section 3.309(e). Significantly, in July 2009, the National Academy of Sciences (NAS) issued "Veterans and Agent Orange: Update 2008" (Update 2008). The Secretary, based upon Update 2008 and prior NAS reports, has specifically concluded that a presumption of service connection based on exposure to herbicides in the Republic of Vietnam is not warranted for hypertension. See 75 Fed. Reg. 32540 (June 10, 2008). Notwithstanding the foregoing presumption provisions, the Federal Circuit Court has determined that a claimant is not precluded from establishing service connection with proof of direct causation. Combee v. Brown, 34 F.3d 1039, 1042 (Fed. Cir. 1994). Nevertheless, the claim is also denied on a direct basis. First, there is no evidence of hypertension in service. As above, all service examinations show normal blood pressure readings and a normal heart. Also, there is no history of hypertension until at least 1972, approximately five years after service. Such a lapse of time is a factor for consideration in deciding a service connection claim. Maxson v. Gober, 230 F.3rd 1330, 1333 (Fed. Cir. 2000). Moreover, the December 2010 VA examiner determined that, based on time period in which the Veteran's hypertension manifested (5 to 8 years after discharge), it did not exist in service, did not originate in service, and was not etiologically related to service. As the examiners offered clear conclusions with supporting data as well as reasoned medical explanations connecting the two, the Board accords great probative weight to his opinion. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008); Stefl v. Nicholson, 21 Vet. App. 120, 124 (2007) ("[A]medical opinion ... must support its conclusion with an analysis that the Board can consider and weigh against contrary opinions"). Finally, the Board finds that service connection for hypertension as secondary to diabetes mellitus is not warranted. In this regard, both the December 2010 VA examiner and February 2013 VHA examiner specifically opined that the Veteran's hypertension was not caused by his diabetes mellitus as the Veteran's hypertension predates his service-connected diabetes as well as his diabetic nephropathy by several years. With regard to whether the hypertension is aggravated by the Veteran's service-connected diabetes mellitus, as above, the February 2013 VHA examiner could find no evidence that the Veteran's blood pressure was more difficult to control since the development of diabetes mellitus or evidence that the hypertension related complication left ventricular hypertrophy is associated with the poorly controlled blood pressure. As both VA examiners offered clear conclusions with supporting data as well as reasoned medical explanations connecting the two, the Board accords great probative weight to their opinions. See Nieves-Rodriguez, supra; Stefl, supra. While the Veteran contends that his hypertension is related to military service or secondary to diabetes mellitus, the Board accords his statements regarding the etiology of this disorder little probative value as he is not competent to opine on such a complex medical question. Specifically, where the determinative issue is one of medical causation, only those with specialized medical knowledge, training, or experience are competent to provide evidence on the issue. See Jones v. West, 12 Vet. App. 460, 465 (1999). In this regard, the question of causation and aggravation of hypertension involves a medical subject concerning an internal physical process extending beyond an immediately observable cause-and-effect relationship. As such, the question of etiology in this case may not be competently addressed by lay evidence, and the Veteran's own opinion is nonprobative evidence. See Jandreau, supra; see also Woehlaert v. Nicholson, 21 Vet. App. 456 (2007) (although the claimant is competent in certain situations to provide a diagnosis of a simple condition such as a broken leg or varicose veins, the claimant is not competent to provide evidence as to more complex medical questions). Therefore, based on the foregoing, the Board finds that service connection for hypertension is not warranted on a presumptive, direct, or secondary basis. In reaching this decision, the Board has considered the applicability of the benefit of the doubt doctrine. However, the preponderance of the evidence is against the Veteran's claim of entitlement to service connection hypertension. As such, that doctrine is not applicable in the instant appeal, and his claim must be denied. 38 U.S.C.A. § 5107; 38 C.F.R. § 3.102; Gilbert, supra. ORDER Service connection for hypertension is denied. ____________________________________________ A. JAEGER Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs