Citation Nr: 21070451 Decision Date: 11/24/21 Archive Date: 11/24/21 DOCKET NO. 16-58 635A DATE: November 24, 2021 ORDER Entitlement to a kidney disorder is denied. Entitlement to service connection for obstructive sleep apnea, to include as due to the Veteran's service-connected disabilities, is denied. Entitlement to service connection for diabetes mellitus II (DMII), to include as due to the Veteran's service-connected disabilities, is denied. FINDINGS OF FACT 1. The record of evidence does not support a finding that the Veteran has a kidney disorder during the appeal period. 2. The preponderance of the evidence is against a finding that the obstructive sleep apnea is etiologically related to any service-connected disability. 3. The preponderance of the evidence is against a finding that the DMII is etiologically related to any service-connected disability. CONCLUSIONS OF LAW 1. The criteria for entitlement to service connection for a kidney disorder have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. § 3.303, 3.310. 2. The criteria for entitlement to service connection for obstructive sleep apnea due to service-connected disabilities have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. § 3.303, 3.310. 3. The criteria for entitlement to service connection for DMII due to service-connected disabilities have not been met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. § 3.303, 3.310. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from June 1979 to August 1987, with additional Reserve service. This case comes before the Board of Veterans' Appeals (Board) on appeal from May 2017 and May 2018 rating decisions of the Department of Veteran Affairs (VA) Regional Office (RO). The Veteran testified before the undersigned Veterans Law Judge in a June 2020 hearing. These issues, along with a separate claim of entitlement to service connection for a left shoulder disability, were previously before the Board in December 2020. Service connection for the left shoulder disability was granted, and the remaining issues were remanded for further development. In a December 2021 rating decision, the RO effectuated that grant with a 20 percent evaluation effective December 31, 2014. This represents a full grant of the benefits sought, and this issue is no longer in appellate status. See Grantham v. Brown, 114 F. 3d 1156, 1158 (Fed. Cir. 1997). The development for the present issues was completed, and the case has since been returned to the Board for appellate review. Service Connection Service connection may be granted for a disability resulting from disease or injury incurred in or aggravated by active service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, a Veteran 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 - the so-called "nexus" requirement. Holton v. Shinseki, 557 F.3d 1362, 1366 (Fed. Cir. 2009) (quoting Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004)). Service connection may be granted for any disease initially 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). Service connection may also be granted on a secondary basis for disability which is proximately due to or the result of service-connected disease or injury, or for additional disability resulting from the aggravation of a nonservice-connected disability by a service-connected disability. 38 C.F.R. § 3.310 (2018); Allen v. Brown, 7 Vet. App. 439, 448 (1995) (en banc). In addition, service connection for certain chronic diseases may be established on a presumptive basis by showing that the condition manifested to a degree of 10 percent or more within one year from the date of separation from service. 38 U.S.C. §§ 1101, 1112, 1113, 1131, 1137; 38 C.F.R. §§ 3.307, 3.309(a); Fountain v. McDonald, 27 Vet. App. 258, 271-72 (2015). Although the disease need not be diagnosed within the presumptive period, it must be shown, by acceptable lay or medical evidence, that there were characteristic manifestations of the disease to the required degree during that time. 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309(a). Additionally, for certain chronic diseases with potential onset during service, there is required a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time. If chronicity in service is not established, a showing of continuity of symptoms after discharge may support the claim. 38 C.F.R. §§ 3.303(b), 3.309; Walker v. Shinseki, 708 F.3d 1331 (Fed. Cir. 2013). 1. Entitlement to a kidney disorder The Veteran alleged at the June 2020 Board hearing that they have a kidney disorder which began during service and has existed since that time. October 1982 service treatment records (STRs) indicate a history of one to two years of dark yellow urine post-intercourse, with no other urinary symptoms, and note proteinuria and hematuria. November 1982 STRs indicate microscopic hematuria and proteinuria. On a May 1985 Report of Medical History, the Veteran endorsed a history of kidney stones or blood in the urine. April 1987 STRs note intermittent proteinuria since 1981. A May 1987 nephrology consultation indicates that the Veteran declined a percutaneous procedure to determine a diagnosis, but that they would follow up on the renal function in 6 to 12 months. The Veteran first applied for service connection for a kidney disorder upon separation from active duty, and underwent a VA examination in December 1987. There, the Veteran repeated their history of proteinuria and treatment of kidney problems during service, and that they had been told that the kidney would not get any worse or any better. The examiner noted that the Veteran was told it was a chronic interstitial nephritis or chronic glomerular disease of unknown etiology, and that the Veteran had declined to do a renal biopsy because of the small likelihood of finding any treatable pathology. The examiner concurred with the assessment that the condition was likely chronic interstitial disease or chronic glomerular disease of unknown origin that was asymptomatic at the moment with no evidence of progression between 1981 and the present, and no other remarkable findings. The claim of entitlement to service connection was denied in February 1988 based on no findings of a urologic pathology. A new VA medical opinion was obtained in February 1988. There, the examiner noted that in 1981 the Veteran had a sudden onset of severe backache with dark yellow urine, and that it was noted at the time that they had microscopic hematuria, protein, and some pyuria. Intermittent examinations over the years had been done, and the backache intermittently continued. The examiner explained that the backache was not related to the kidney situation, and that the Veteran had had no urinary symptoms such as frequency, dysuria, gross hematuria, or urinary incontinence. The examiner opined that there is a likelihood of glomerular or chronic tubular nephritis, but that it is unlikely that a diagnosis would actually be found. The examiner recommended that in the absence of symptoms but the presence of intermittent urinary findings, and the nebulous conclusions by nephrologists, periodic examinations should be performed on an annual basis if there is no symptomatology to further evaluate and elucidate the nebulous renal problem and its clinical significance. The Veteran has repeatedly asserted continued kidney problems, although the record is absent a diagnosis of a kidney disorder during the present appeal period. March 2013 VA treatment records note that kidney function was within normal limits. A June 2015 erectile dysfunction VA examination found no renal dysfunction. August 2015 VA treatment records found no change in urine output or color, dysuria, or flank pain. May 2017 VA treatment records indicate that kidney function had creatinine in good range, that urine did not reveal any macroscopic protein loss, and that microalbumin was negative. June 2017 VA treatment records note that the last kidney function labs were within normal limits and that they did not recommend referral to a nephrologist. August 2017 VA treatment continue to note that kidney lab work was within normal limits. The Veteran underwent a VA examination in December 2017 where the examiner noted the findings of intermittent hematuria and proteinuria while in service, associated with bilateral flank pain, and foul-smelling urine. The Veteran reported that their last episode was in December 2016, that they currently had bilateral flank pain, and that there were no episodes in the prior 3 years. The examiner noted that BUN, creatinine, and EGFR were all normal. In providing their medical opinion, the examiner stated that it is at least as likely as not that the claimed condition incurred in service, explaining that the Veteran did not have a diagnosis of hematuria or proteinuria prior to military service. The examiner stated that the specific etiology of chronic kidney disease is unclear, and recommended further evaluation to determine the cause of hematuria, proteinuria, and current flank pain. In January 2018, the RO requested an addendum medical opinion to clarify if there is a diagnosis of a chronic kidney condition, as hematuria and protein uria are merely lab findings. A new medical opinion was issued, indicating that while the Veteran has a history of abnormal labs, current lab values showed that the kidney function was normal, and that there was no diagnosis of a kidney disorder. As such, the examiner determined that a nexus was not established. April 2018 VA treatment records note the Veteran's reports of being unable to take non-steroidal anti-inflammatory drugs due to their kidney condition, but the examiner was unable to find any information regarding kidney damage in the Veteran. There, the Veteran also reported that their kidneys were managed outside VA. At the June 2020 Board hearing, the Veteran reported that they were being treated to keep their EGFR higher, but that they were not currently diagnosed with anything. They explained that their urine was brown in December 2016, and that their private treating physician instructed that they no longer take aspirin, naproxen, or Meloxicam. The Veteran asserted that their EGFR levels indicates that they are just above stage 3 kidney disease, but still not at a high enough level to warrant treatment. VA treatment records indicate that the Veteran sought private treatment for the kidney condition, and the December 2020 Board decision remanded in part to obtain those records. The RO sent the Veteran a letter in December 2020 requesting that they identify and authorize those records for release. The Veteran did not reply to this letter, or submit any additional private treatment records (PTRs). The duty to assist a claimant is not a one-way street, and in the instant case, the Veteran must cooperate by responding to the RO's request for authorization to request records to the full extent in the development of the claim. See Wood v. Derwinski, 1 Vet. App. 406 (1991) (noting that VA's duty to assist is a two-way street, and the Veteran cannot wait passively in those situations where their assistance to VA is necessary). As the Veteran did not cooperate with the development of this claim, the Board will proceed with adjudication based on the records present in the claims file. Based on the preponderance of the evidence above, the Board finds that service connection for a kidney disorder is not warranted. As noted by the January 2018 addendum VA medical opinion, hematuria and proteinuria are lab findings, and not an actual diagnosis. VA treatment records have consistently noted that kidney function has been within normal limits throughout the appeal period. Although the Veteran has asserted that they have "stage 3 kidney disease," this is not reflected by the record, and the Veteran has not submitted any evidence to support such a finding. And while the December 1987 VA medical opinion noted a likely diagnosis of chronic interstitial disease or chronic glomerular disease, and the February 1988 VA medical opinion noted a likelihood of glomerular or chronic tubular nephritis, these do not reflect a current diagnosis during the appeal period. The requirement for service connection that there be a current disability is satisfied when the disability is shown at the time of the claim or during the pendency of the claim, even though the disability subsequently resolves. McClain v. Nicholson, 21 Vet. App. 319 (2007). The Board affords the January 2018 addendum VA medical opinion great probative value as it reflects careful consideration of the record, and is supported by a well-reasoned rationale. A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 301 (2008). The Board affords the December 2017 VA medical opinion low probative value as it is based on lab findings, and not an actual diagnosis. Regarding the Veteran's statements that they have a current kidney disorder, the Board recognizes that lay witnesses may, in some circumstances, opine on questions of diagnosis and etiology. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. Sept. 14, 2009) (Board's categorical statement that "a valid medical opinion" was required to establish nexus, and that a layperson was "not competent" to provide testimony as to nexus because she was a layperson, conflicts with Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007)). However, while the Veteran is competent to provide their lay description of symptoms, they are not competent to diagnose or opine on medical etiology for complex medical questions requiring specific medical knowledge and training. See Rucker v. Brown, 10 Vet. App. 67, 74 (1997) (stating that a lay person is not competent to diagnose or make a competent nexus opinion about a disorder as complex as cancer). This case involves complex medical matters and requires specific testing to confirm a diagnosis. The question of whether the Veteran has a current kidney disorder requires objective medical evidence, which, in this case, according to the most probative evidence of record (the January 2018 addendum VA medical opinion), is absent. Accordingly, the first element of service connection the presence of a current disability is not met, and the claim of entitlement to service connection for kidney disorder is denied. In reaching this decision the Board considered the doctrine of reasonable doubt, however, as the preponderance of the evidence is against the Veteran's claim, the doctrine is not for application. Gilbert v. Derwinski, 1 Vet. App. 49 (1990). 2. Entitlement to service connection for obstructive sleep apnea, to include as due to the Veteran's service-connected disabilities The Veteran alleges that sleep apnea began during service and has existed since that time. First, the Board finds that there is a current disability. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). September 2015 VA treatment records indicate a diagnosis of severe obstructive sleep apnea. Accordingly, the first element of service connection is met. Second, the Board finds that there was an in-service event, injury or disease. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). The Veteran's STRs are silent for any complaints of or treatment for sleep apnea. On the various reports of medical history, the Veteran generally denied frequent trouble sleeping, except for the May 1985 report, as well as the June 1992 report for the Veteran's post active-duty Reserve service. A November 2015 statement from a fellow servicemember and former roommate indicated that they observed the Veteran snoring, choking, gagging, and vomiting in their sleep. Also, in November 2015, the Veteran's spouse submitted a stating asserting that they began dating in 1987 prior to separation, and that the Veteran snored all the time and had sleep issues from the start of the relationship. They also indicated that they have some medical training, but did not provide any further detail, and suggested that the Veteran most likely had sleep apnea during service. At the June 2020 Board hearing, the Veteran asserted that they were overweight while in service, and had been on a weight management program. A May 1985 report of medical examination does indicate that the Veteran was 74 inches tall and weight 214 pounds. A July 1987 report notes that the Veteran was 230 pounds. The Board finds these statements competent as they are capable of lay observation. 38 U.S.C. § 1154(a) (2012); The Board finds these statements credible as they are corroborated by the Veteran's STRs. Washington v. Nicholson, 19 Vet. App. 362, 368 (2005) (noting that a lay witness is competent to report to factual matters of which he or she has first-hand knowledge); Caluza v. Brown, 7 Vet. App. 498, 511 (1995) (noting that the credibility of a witness may be impeached by a showing of interest, bias, inconsistent statements, consistency with other evidence), aff'd, 78 F.3d 604 (Fed. Cir. 1996). At the June 2020 Board hearing, the Veteran also asserted that the sleep apnea may be related to the service-connected hypertension, gastroesophageal reflux disease (GERD), and posttraumatic stress disorder (PTSD). Accordingly, the second element of service connection is met. Third, the Board finds that the evidence of record does not support a finding that the sleep apnea is related to active service. In February 2021 the RO obtained a VA medical opinion based on a review of the records. The examiner provided a negative nexus opinion, explaining that the STRs are silent for a diagnosis of sleep apnea or subjective complaints of snoring, hypersomnolence, grasping in sleep, or periods of cessation of breathing during sleep. The examiner stated that the Veteran was not diagnosed with sleep apnea until 2015, approximately 28 years following separation. The examiner explained that obstructive sleep apnea usually begins with snoring due to airway obstructions at the level of the soft palate, uvula, tonsils, and tongue, and occurs when the muscles in the back of the throat relax too much to allow normal breathing. The examiner stated that the six main risk factors for the development of sleep apnea include age, gender, obesity, craniofacial and upper airway abnormalities, with obesity being the strongest risk factor. Regarding obesity, the examiner reiterated that obesity does not cause obstructive sleep apnea, but rather is a risk factor for the development, along with other risk factors. The examiner explained that there are many people with obstructive sleep apnea who are not obese, and many that are obese do not have sleep apnea. The examiner opined that obesity is not an absolute factor for the development of sleep apnea, and similarly, snoring is not an objective finding for a diagnosis of sleep apnea. Acknowledging the lay statements of witnessing the Veteran's apneic episodes during service, the examiner explained that a diagnosis of obstructive sleep apnea requires five or more predominantly obstructive respiratory events per hour of sleep, and these witnessed apneas by the Veteran's spouse and roommate are not diagnostic of obstructive sleep apnea. Accordingly, the examiner opined that less likely than not that the obesity was a substantial factor for causing sleep apnea, and it is less likely than not that the sleep apnea would not have occurred but for the obesity since non-obese people have obstructive sleep apnea as well, and multiple risk factors are associated with the development. Regarding secondary service connection, the examiner provided detailed medical descriptions of each of the Veteran's service-connected disabilities, to include PTSD, lumbosacral strain, chronic prostatitis, migraines, sinusitis, radiculopathy of the bilateral lower extremities, tinnitus, bilateral eye conjunctivitis, left shoulder impingement syndrome, GERD, erectile dysfunction, rhinitis, and hypertension. The examiner explained that there is a lack of a pathophysiological relationship between each of these conditions, and emphasizing the etiology of obstructive sleep apnea above, the examiner opined that it is therefore less likely than not that they caused or aggravated the sleep apnea. In July 2021, the Veteran underwent a VA examination where the examiner provided a negative nexus opinion. The examiner explained that sleep apnea was not incurred in or etiologically related to service. The examiner stated that the records failed to reveal any evidence to suggest or support that the sleep apnea diagnosed nearly three decades following separation were incident to service given the significant interval history. The examiner explained that while the risk factors include being male, aging, and obesity, these are not causal but simply risk factors which would not automatically result in the development of obstructive sleep apnea, which is considered a multifactorial condition. Regarding obesity, the examiner explained that while the Veteran's obesity had its genesis during service well before any said service-connected disability would have had influence on their weight, to include aggravation. The examiner noted that the mass body index (BMI) was 32% at separation, but that the Veteran had not been administratively separated for failing to meet height weight standards despite their body habitus while serving on active duty. The examiner explained that the obesity was already present at the time the service-connected disabilities had been established as primary injuries incurred while in active duty. The examiner stated that the obesity had not taken a different clinical course because of the service-connected disabilities, given that it was already present while on active duty before being rated for the primary injuries incident to service. In regard to the Veteran's weight as the cause of the obstructive sleep apnea, the examiner explained that it is not possible to clearly determine the exact cause of weight gain with absolute certainty since it is a condition that is multifactorial in nature and etiology. The examiner explained that while it is possible that some medications for the service-connected PTSD contributed to weight gain, by themselves they would not be responsible for obesity given that the Veteran was overweight at the time of enlistment and throughout service. The examiner stated that morbid obesity is caused by lifestyle and genetics, with the most important factor being calorie consumption and energy expenditure. The examiner explained that given the Veteran's incremental increase in the BMI since separation representing a 28-year period, this represents a volitional weight gain. The examiner stated that weight gain in males is due to the transition from active lifestyle to a more sedentary one, and is expected to have a continual rise in weight until the sixth decade of life, which is also attributed to a decrease in testosterone. While dietary preferences influence weight gain, it is not possible to ascertain daily consumption habits without resort to speculation, although it is certain that the Veteran is exceeding daily intake requirements resulting in a surplus caloric state. The examiner explained that medical literature fails to reveal any causal or pathophysiologic etiology of the service-connected PTSD and sleep apnea, and that there is no evidence that the PTSD caused or aggravated the sleep apnea. The examiner also opined that the other service-connected disabilities are unlikely to have contributed significantly to the weight gain. For PTSD, GERD, and hypertension in particular, there would need to be determined an event, condition, or characteristic without which the disease would not have occurred and must precede effect. On these grounds, the examiner opined that it is less likely than not that the service-connected disabilities caused or aggravated the obesity. Regarding secondary service connection, the examiner explained that there are no publications or scientific literature which would support a causal relationship between hypertension and GERD, and obstructive sleep apnea due to those specific conditions. The examiner stated that it is generally not accepted or supported that these would result in or worsen sleep apnea. Regarding PTSD, the examiner explained that there is no rationale which would support PTSD as an etiological cause of sleep apnea. The examiner stated that an association or risk factor is simply not strong enough given the pathophysiology of sleep apnea is well understood, and that records do not support any causal relationship, or aggravation of the sleep apnea. The examiner explained that while there is a statistical correlation between combat soldiers and obstructive sleep apnea and other sleep disturbances, no causal link is identified. Sleep apnea is a multifactorial condition associated with upper airway obstruction and decreased central respiratory drive. The examiner identified primary risk factors to include male gender, obesity, and advancing age, and stated that mental disorders are not a recognized risk factor for sleep apnea. Regarding a possible connection between allergic rhinitis and sinusitis, the examiner again described that the important risk factors for obstructive sleep apnea are age, male gender, obesity, and craniofacial or upper airway soft tissue abnormalities. Rhinosinusitis refers to inflammation and swelling of the nasal passages and sinuses which are located in the forehead and cheek area, and can interrupt sleep, but does not cause blockage of the throat. The examiner noted a 2016 study stating that there was no definite correlation between obstructive sleep apnea and sinusitis, and that chronic rhinosinusitis patients with comorbid obstructive sleep apnea need to treat the sleep apnea with effective therapeutic measures targeting sleep apnea. The examiner explained that while both conditions affect sleep, independently of each other, there is nothing to support chronic sinusitis causes obstructive sleep apnea. Therefore, the examiner opined that the literature does not support a causal role of allergic rhinitis and obstructive sleep apnea, and would have developed regardless of the sinusitis and rhinitis. The examiner noted that in addition, if rhinitis were the cause, then treatment would then be considered curative of the sleep apnea, which has not been shown in the medical literature or review of the records. The examiner noted that there are no records which reveal that the obstructive sleep apnea has taken a different clinical course, and that the Veteran is compliant on use of medical devices for the treatment of sleep apnea. The examiner explained that there is no evidence to suggest aggravation or any worsening of the sleep apnea by any service-connected disability. Based on a preponderance of the evidence, the Board finds that the claim of entitlement to service connection for obstructive sleep apnea is not warranted. The Board affords both the February and July 2021 VA medical opinions great probative value. They reflect a thorough review of the evidence and consideration of the Veteran's various lay statements, cite to relevant medical literature, and are supported by well-reasoned rationale and relevant medical evidence. Factors for assessing the probative value of a medical opinion include the thoroughness and detail of the opinion. Prejean v. West, 13 Vet. App. 444, 448-9 (2000). A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez, 22 Vet. App. at 301 (2008). The Board has also considered the Veteran's statements in support of their claim. While the Veteran is competent to report on their symptoms, the Board finds the Veteran not competent to offer an opinion as to whether the obstructive sleep apnea is related to any instance of their service since the record does not indicate that they possess the requisite medical knowledge to offer such an opinion. Specifically, the etiology of such disorders involves a medical subject concerning an internal physical process extending beyond an immediately observable cause-and-effect relationship. Although the Veteran's spouse asserted that they have some medical training, they provided no further information. Therefore, as such is a complex medical question, the Veteran is not competent to offer an opinion as to the etiology of the obstructive sleep apnea, and, consequently, their opinion on such matters is afforded no probative weight. Woehlaert v. Nicholson, 21 Vet. App. 456 (2007). The Board has also considered whether presumptive service connection can be established where there is evidence of continuity of symptomology of a chronic condition since service. See 38 C.F.R. § 3.309. However, sleep apnea is not a chronic condition under 38 C.F.R. § 3.309, and the record of evidence does not show a diagnosis until many years following separation from active-duty service. Therefore, consideration based on presumptive service connection for continuity of symptomatology is not warranted. As there is no other medical opinion or any competent and credible evidence in significant conflict with the VA examiner's opinion, the Board finds that the preponderance of the evidence is against a finding that the Veteran's sleep apnea is related to military service. Accordingly, service connection is denied. Accordingly, service connection is denied. In reaching this decision the Board considered the doctrine of reasonable doubt, however, as the preponderance of the evidence is against the Veteran's claim, the doctrine is not for application. Gilbert, 1 Vet. App. 49. 3. Entitlement to service connection for DMII, to include as due to the Veteran's service-connected disabilities, The Veteran alleges that diabetes is secondary to their service-connected disabilities. First, the Board finds that there is a current disability. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). A July 2021 VA examination confirms a diagnosis of diabetes mellitus II. Accordingly, the first element of service connection is met. Second, the Board finds that there was an in-service injury or disease. See Holton, 557 F.3d at 1366; 38 C.F.R. § 3.303(d). The Veteran's STRs are silent any complaints of or treatment for diabetes. The Veteran asserted at the June 2020 Board hearing that the diabetes is due to the obstructive sleep apnea, which, as noted above, they asserted was a result of obesity due to their service-connected disabilities. Accordingly, the second element of service connection is met. Third, the Board finds that the evidence of record does not support a finding that the diabetes mellitus II is related to active service. In February 2021 the RO obtained a VA medical opinion based on a review of the records. As noted above, the examiner provided detailed medical descriptions of each of the Veteran's service-connected disabilities, to include PTSD, lumbosacral strain, chronic prostatitis, migraines, sinusitis, radiculopathy of the bilateral lower extremities, tinnitus, bilateral eye conjunctivitis, left shoulder impingement syndrome, GERD, erectile dysfunction, rhinitis, and hypertension, in addition to diabetes. The examiner explained that diabetes is an impairment in the way the body regulates and uses sugar as a fuel, and results in too much sugar circulating in the bloodstream. The examiner stated that diabetes is primarily the result of two interrelated problems: 1) the cells in muscle, fat, and liver become resistant to insulin; and 2) because they do not interact in a normal way with insulin, they do not take in enough sugar, or the pancreas is unable to produce enough insulin to manage blood sugar levels. The examiner noted factors that may increase the risk of DMII, to include weight, fat distribution, inactivity, family history, race and ethnicity, blood lipid levels, and age. The examiner explained that obesity is a complex disease involving an excessive amount of body fat, and that it is a medical problem that increases the risk of other diseases, including diabetes. The examiner stated that being obese is not an absolute condition for the development for DMII, although it is a strong risk factor. The examiner opined that it is less likely than not that the diabetes would not have occurred but for the obesity since non-obese people have diabetes as well, and multiple risk factors are associated with the development. The Veteran underwent a VA examination in July 2021 where the examiner provided a negative nexus opinion. The examiner explained that DMII is a condition with risk factors being family history, being overweight, having hypertension, being physically inactive, being 45 years or older, amongst many other contributing factors. The examiner stated that the pathophysiology of DMII is complicated by several factors, to include varying degrees of insulin resistance, relative insulin deficiency as contributing to DMII, each clinical feature can arise due to the combination of genetic or environmental influences, making it difficult to determine the exact cause in any individual with any certainty. The examiner opined that the Veteran's service-connected disabilities do not have any significant contribution to the obesity, and that the obesity is only considered a risk factor which would not be clinically predictable as the cause. The examiner explained that the record fails to reveal any causal relationship between the service-connected disabilities and the diabetes. Regarding aggravation, the examiner explained that the Veteran is managed with a single low maintenance dose medication, and records do not reveal that the diabetes has taken any other clinically predicted course by any service-connected disability. The examiner opined that there are no records to suggest that any service-connected disability has had any deleterious affect on the DMII beyond its natural progression. Specifically, again, regarding obesity, the examiner explained that while the Veteran's obesity had its genesis during service well before any said service-connected disability would have had influence on their weight, to include aggravation. The examiner noted that the mass body index (BMI) was 32% at separation, but that the Veteran had not been administratively separated for failing to meet height weight standards despite their body habitus while serving on active duty. The examiner explained that the obesity was already present at the time the service-connected disabilities had been established as primary injuries incurred while in active duty. The examiner stated that the obesity had not taken a different clinical course because of the service-connected disabilities, given that it was already present while on active duty before being rated for the primary injuries incident to service. Based on a preponderance of the evidence, the Board finds that entitlement to service connection for diabetes mellitus II is not warranted. The Board affords the July 2021 VA medical opinion great probative value. It reflects a thorough review of the evidence, cite to relevant medical literature, and is supported by well-reasoned rationale and relevant medical evidence. Factors for assessing the probative value of a medical opinion include the thoroughness and detail of the opinion. Prejean, 13 Vet. App. at 448-9. A medical examination report must contain not only clear conclusions with supporting data, but also a reasoned medical explanation connecting the two. Nieves-Rodriguez, 22 Vet. App. at 301. The Board affords the February 2021 VA medical opinion less probative value. Although it reflects a thorough review of the evidence, and is supported by well-reasoned rationale and relevant medical evidence, it only discussed whether obesity was a substantial factor in the development of DMII, and did not directly address secondary service connection. The Board has also considered the Veteran's statements in support of their claim. While the Veteran is competent to report on their symptoms, the Board finds the Veteran not competent to offer an opinion as to whether the DMII is related to any instance of their service since the record does not indicate that they possess the requisite medical knowledge to offer such an opinion. Specifically, the etiology of such disorders involves a medical subject concerning an internal physical process extending beyond an immediately observable cause-and-effect relationship. Therefore, as such is a complex medical question, the Veteran is not competent to offer an opinion as to the etiology DMII, and, consequently, their opinion on such matters is afforded no probative weight. Woehlaert, 21 Vet. App. 456. The Board has also considered whether presumptive service connection can be established where there is evidence of continuity of symptomology of a chronic condition since service. See 38 C.F.R. § 3.309. However, although diabetes mellitus is a chronic condition under 38 C.F.R. § 3.309, the record of evidence does not show a diagnosis until many years following separation from active-duty service. Therefore, consideration based on presumptive service connection for continuity of symptomatology is not warranted. As there is no other medical opinion or any competent and credible evidence in significant conflict with the VA examiner's opinion, the Board finds that the preponderance of the evidence is against a finding that the Veteran's DMII is related to military service. Accordingly, service connection is denied. (Continued on the next page) In reaching this decision the Board considered the doctrine of reasonable doubt, however, as the preponderance of the evidence is against the Veteran's claim, the doctrine is not for application. Gilbert, 1 Vet. App. at 49. KELLI A. KORDICH Veterans Law Judge Board of Veterans' Appeals Attorney for the Board J. Rogos 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.