Type 2 Diabetes Secondary to Sleep Apnea Claim Guide
Type 2 Diabetes (VA diagnostic code 7913) is sometimes claimed as secondary to service-connected Sleep Apnea (code 6847) under 38 CFR 3.310. We analyzed published Board of Veterans' Appeals decisions on that pairing; here is what they show. It is an encyclopedic reference, not a forecast.
The Numbers, from 1.9M Appeals
We analyzed the Board's published decisions and found type 2 diabetes (DC 7913) claimed as secondary to sleep apnea (DC 6847) is a small but documented claim pool that wins clearly more often than it loses once it reaches a merits decision.
How those 198 issues came out
ICD-10 Diagnosis Codes for Type 2 Diabetes
The ICD-10 diagnosis codes most commonly used for DC 7913, Type 2 Diabetes (the kind on your medical records, decision letter, or C&P exam report). VA rates the disability and its residuals, not the diagnosis itself, so coding can vary.
What a secondary claim on this pairing needs
Under 38 CFR 3.310 a secondary claim turns on three elements:
- A current diagnosis: a medical diagnosis of type 2 diabetes (the secondary).
- A service-connected primary: Sleep Apnea, already service-connected (the primary). A 0% primary still counts.
- A medical nexus: a medical opinion linking the type 2 diabetes to the sleep apnea, showing the primary caused or aggravated it.
See the Secondary Claim guide for the caused-versus-aggravated split, and the Nexus Letter guide for what makes the medical opinion strong.
Why type 2 diabetes is claimed secondary to sleep apnea
Whether that medical link exists in any one case is a medical question decided on that case's own evidence (the nexus).
Caused By vs Aggravated By: What the Board Found
The outcome split above counts whole issues. This section goes one layer deeper. Under 38 CFR § 3.310 a secondary claim can be won two ways: the sleep apnea caused the type 2 diabetes (§ 3.310(a)), or it aggravated an existing type 2 diabetes (§ 3.310(b)). Every grant rests on one or the other, so the numbers below divide up the granted claims only.
Direct causation is the route that carries most grants here: 85% of them found the sleep apnea caused the type 2 diabetes, the rest found aggravation. A practical consequence for the nexus opinion: it should address both routes, because a medical opinion that only argues causation leaves the aggravation theory, a separate legal basis, on the table. See the caused-vs-aggravated guide for how the two theories differ.
On the other side: in 18 denied claims the Board looked at this pairing and found no link, meaning it decided the sleep apnea neither caused nor worsened the type 2 diabetes. That is a separate group from the grants above, counted here so the picture is not one-sided.
We analyzed published Board decisions on this pairing to build this split. The grant split covers granted claims only; denied, remanded, and dismissed claims are not in it. Descriptive of the published record, not a prediction.
What VA Looks For: Tests, Records, and Diagnostic Codes
The record VA actually reviews centers on a small set of documents. We analyzed published Board decisions on these claims and ranked the records that appeared most often:
- A medical nexus opinion: the one record VA weighs most on a secondary claim, a doctor's statement linking your type 2 diabetes to your service-connected sleep apnea and naming the mechanism.
- Herbicide (Agent Orange) presumption addressed
- Restricted diet or oral agents documented
- Regulation of activities addressed
- Insulin requirement documented
- Diabetic complications claimed as secondary
- A1C or glucose readings in the record
The diagnostic code involved: DC 7913 (Type 2 Diabetes). The rating levels for this code are in the rating section below.
Records ranked by how often published Board decisions cited them. The exam that captures most of this is covered in the C&P Exam section below. Source: Board of Veterans' Appeals decisions, RateMyVSO analysis.
The Evidence That Wins Type 2 Diabetes Secondary Claims
What veterans who win this pairing actually put in the file, and why each piece moves the claim.
- Sleep study with your AHI score: This shows how severe your sleep apnea is and how many times a night your breathing stopped. The more episodes, the stronger your case that low oxygen was hurting your blood sugar control. Get the date of this test so it can be lined up against your diabetes records.
- HbA1c and fasting glucose results over time: Pull these from your medical record going back as far as you can, before and after your sleep apnea diagnosis. If your blood sugar got worse or became harder to control around the time your apnea started (or went untreated), that timing is some of your strongest evidence.
- Weight records from the date your sleep apnea was service connected to today: This one matters a lot. If the VA sees your weight went up, they may say obesity, not sleep apnea, caused your diabetes. If your weight stayed steady but your blood sugar still got worse, that helps prove sleep apnea acted directly on your body, not just through weight gain.
- CPAP compliance and blood sugar response after you started using it: If your HbA1c improved after you got on CPAP and started using it regularly, that is powerful proof your untreated apnea was part of what was driving your diabetes.
- Insulin resistance testing, if you have it (HOMA-IR or fasting insulin levels): This measures the actual mechanism, sleep apnea making your body resistant to insulin. It matters most if this got worse while your weight held steady, because it breaks the argument that weight was the only factor.
- A nexus letter that uses the right words and your actual numbers: The letter needs to say plainly that it is "at least as likely as not" that your sleep apnea caused or aggravated your diabetes. It should use your real dates and lab values, not just talk about diabetes and sleep apnea in general. Soft words like "can cause" or "may contribute" are not enough and get denied.
- The letter should cover both causation and aggravation: Your sleep apnea may have caused your diabetes, or it may have made an existing diabetes worse. These are two different legal doors. A strong letter addresses both, so you are not shut out if the VA argues one doesn't apply to you.
- A doctor's explanation of your own case, not general research: Studies on sleep apnea and diabetes in the population are useful background, but the VA wants to know what happened in YOUR body. The best letters walk through your personal timeline: when you were diagnosed, how your labs changed, and how CPAP affected you.
Evidence Cited in Published Diabetes (type 2) Decisions
We analyzed 49,872 published Board decisions involving diabetes (type 2) for condition-specific evidence, counting only case-specific mentions (boilerplate recitations excluded). "Favorable" is the share of decisions citing that evidence where every issue was granted or the outcome was mixed; the baseline across all these decisions is 54.8%. Evidence appearing in a decision does not mean it decided the case. Descriptive of the published record, not a prediction.
Detected by phrase-reading the decision text with condition-specific vocabularies. Source: Board of Veterans' Appeals decisions, RateMyVSO analysis.
Board Grants on This Pairing, Dissected
The Board has granted service connection for diabetes mellitus, type II, as secondary to sleep apnea in several published decisions. These decisions are not binding on other claims, but they show the kind of evidence that persuaded the Board. Each case turned on a medical opinion that explained, in detail, how sleep apnea or the sleep loss and obesity that come with it can lead to diabetes.
Private doctor's literature review beats no VA opinion at all Citation A26033939 (April 13, 2026), Hearing docket
The record: The Veteran was already service connected for insomnia and obstructive sleep apnea. VA treatment records from 2012 onward documented diabetes mellitus, type II, linked by providers to obesity. No VA medical opinion addressed the secondary theory. A June 2024 private medical doctor reviewed the file and relevant medical literature and opined that the Veteran's diabetes was at least as likely as not caused by lack of sleep from his insomnia, anxiety, and sleep apnea. The doctor explained that lack of sleep causes insulin sensitivity problems, disrupted glucose metabolism, and hormonal imbalances.
Why it won: The Board found the private opinion adequate because the doctor reviewed the record, discussed the medical literature, and gave supporting rationale. Since there was no VA opinion at all, the private opinion stood as the only, and therefore most probative, evidence of record.
Sleep specialist's opinion outweighs an inadequate VA opinion Citation A26026837 (March 25, 2026), Hearing docket
The record: A private examiner, a Board-Certified Sleep Medicine Specialist and Diplomate of the American Board of Sleep Medicine, opined in September 2022 that the Veteran's diabetes was caused by his service-connected sleep apnea, explaining that sleep apnea "causes metabolic changes that result in diabetes." A February 2021 VA opinion was negative. The Veteran also gave hearing testimony that a doctor had linked his diabetes to his sleep apnea.
Why it won: The Board called the rationale in the positive opinion "modest," but found it, combined with the Veteran's competent hearing testimony and the current diagnosis, persuasive. The Board rejected the negative VA opinion because it "impermissibly relies on lack of evidence" rather than actually addressing the Veteran's case.
Obesity as the bridge between sleep apnea and diabetes Citation A26000680 (January 5, 2026), Direct Review docket
The record: The Veteran was already service connected for sleep apnea caused by in-service obesity. A private nurse practitioner (DNP) opined that the Veteran's diabetes was more likely than not caused by his service-connected sleep apnea and morbid obesity, citing medical literature showing obesity and sleep apnea are both major risk factors for type 2 diabetes. Two VA examiners disagreed, one relying on a presumptive-exposure standard that did not apply, the other giving only a conclusory statement.
Why it won: The Board applied the obesity-as-intermediate-step doctrine from Walsh v. Wilkie and VAOGCPREC 1-2017. Because the sleep apnea had already been linked to in-service obesity, and the private opinion tied that obesity to the diabetes, the chain was satisfied. The Board found both VA opinions inadequate because they failed to address obesity as an intermediate step and did not discuss the Veteran's individual facts.
Private opinion that engages with sleep science wins over a "no medical literature" VA denial Citation A25085446 (October 2, 2025), Evidence Submission docket
The record: A July 2023 VA examiner opined against a link, reasoning that there was insufficient medical literature connecting sleep apnea and diabetes. The Veteran submitted medical literature describing sleep apnea's association with insulin resistance and glucose intolerance independent of obesity. A July 2024 private physician reviewed that literature and the Veteran's history and opined that severe, long-untreated sleep apnea can aggravate glucose metabolism through sleep fragmentation and hypoxia, and found this was likely the case for the Veteran.
Why it won: The Board found the VA opinion inadequate because it relied on an absence of general literature without discussing the Veteran's own facts, and because it failed to separately address aggravation. The private opinion applied the literature to the Veteran's specific circumstances, which the Board found established the needed nexus.
An uncontradicted aggravation opinion is enough for the benefit of the doubt Citation A25069076 (August 14, 2025), Evidence docket
The record: A private physician opined in March 2023 that it was at least as likely as not that the Veteran's diabetes mellitus had been aggravated beyond its natural progression by sleep apnea. A March 2022 VA opinion found diabetes was not caused by sleep apnea, but that opinion never addressed aggravation. The Veteran also submitted medical treatise evidence on the sleep apnea and diabetes relationship.
Why it won: Because the VA opinion never addressed aggravation, it did not contradict the private opinion on that theory. The Board found the private opinion, combined with the treatise evidence, was enough to reach at least an approximate balance of evidence, and applied the benefit of the doubt in the Veteran's favor.
What the Board Said in Recent Grants
These are the Board's own words, quoted from the findings in 5 recent granted decisions on this pairing. Each sentence is the finding the grant rested on, not a summary of it. Click a citation to read the full decision.
“The Veteran's diabetes mellitus, type II, is proximately due to the lack of sleep caused by his service-connected insomnia disorder and obstructive sleep apnea.”
“The evidence of record persuasively demonstrates that the Veteran's diabetes mellitus, type II is caused and/or aggravated by his now service-connected obstructive sleep apnea.”
“The evidence is persuasive that the Veteran's diabetes mellitus type 2 was caused by his service-connected sleep apnea by way of obesity.”
“The most probative evidence establishes that the Veteran's diabetes mellitus is secondary to his obstructive sleep apnea”
“There is competent evidence indicating that hypertension and diabetes mellitus type 2 have been aggravated by sleep apnea.”
Quoted from published Board decisions on this pairing, most recent first. Descriptive of the published record, not a prediction about any individual claim. Search the full decisions in BVA Decision Search.
Why VA Denies, and How the Board Answered
The rationales below are the ones VA examiners actually used against this pairing in the published record, each paired with the Board's response.
- Read the left column first: if a VA opinion in your file uses one of these arguments, that is the reasoning your own evidence has to meet.
- The right column is the counter: it shows how the Board actually answered that argument, with the decision cited.
- A rationale appearing here is not a verdict: the same argument won some cases and lost others, on different records.
| VA examiner's rationale | How the Board answered it |
|---|---|
| Medical literature does not support obstructive sleep apnea as a cause of diabetes mellitus, based on a general review of medical literature without tying it to the Veteran's facts. | The Board found this a proper basis to deny where the opposing positive opinion also lacked case-specific rationale and only described general population effects. The negative opinion was found more probative because it applied current medical knowledge to the claim (A24079111, November 29, 2024). |
| Diabetes is caused by insulin resistance, and there is no mechanism by which inactivity or lack of exercise causes insulin resistance; the Veteran's diabetes is more likely tied to poor diet and obesity unconnected to his service-connected disabilities. | The Board found this opinion sufficient despite some deficiencies, because no competent evidence rebutted the insulin-resistance explanation and the record showed the Veteran's obesity was more likely related to diet than to physical limitations from his service-connected conditions (A24056334, September 13, 2024). |
| There is a lack of a known pathophysiologic relationship between sleep apnea and diabetes, correlation in observational studies does not establish causation, and the Veteran's extreme obesity is a separate, well-known cause of his diabetes. | The Board gave this opinion greater weight than the Veteran's lay statements, finding the examiner's rationale addressed the relevant medical literature and considered the Veteran's own obesity as an alternate explanation (A21011898, July 13, 2021). |
| A thorough review of medical literature found no established causal relationship between diabetes and sleep apnea, and diabetes was diagnosed before the Veteran's sleep apnea, undercutting any aggravation theory. | The Board found this addendum opinion adequate and persuasive because it addressed direct, secondary, and toxic-exposure theories individually, with specific reference to onset dates and to the literature the Veteran had submitted (24023943, June 18, 2024). |
| Insulin resistance, genetics, and lifestyle are the recognized causes of type 2 diabetes, and sleep apnea does not cause the insulin resistance that leads to diabetes; a later addendum found no aggravation either, since there is no significant pathological connection between sleep apnea and diabetes. | The Board treated the two VA opinions together as probative because they were based on accurate medical history and gave clear conclusions with supporting data, and found a treatise submitted by the representative too general because it was not tied to the Veteran's own case (23048429, September 5, 2023). |
If Granted: How Type 2 Diabetes Is Rated
The VA assigns one of these percentages based on what your medical record documents. Plain-language summary of the rating criteria at 38 CFR; the controlling text is the regulation itself.
| Rating | What the record has to show for DC 7913, Type 2 Diabetes |
|---|---|
| 100% | You need multiple daily insulin injections, must follow a strict diet, and have to avoid strenuous work or recreational activities. Your diabetes must be severe enough to cause ketoacidosis (dangerous buildup of acids in blood) or hypoglycemic reactions (dangerously low blood sugar) that require either three or more hospitalizations per year or weekly visits to a diabetes specialist. Additionally, you must be experiencing either progressive weight loss and weakening, or have diabetes-related complications serious enough that they would qualify for their own separate VA disability ratings if evaluated individually. |
| 60% | You need daily insulin shots, must follow a strict diet, and have to limit your activities because of your diabetes. Your blood sugar goes dangerously high (ketoacidosis) or dangerously low (hypoglycemic reactions) often enough that you're hospitalized 1-2 times per year or need to see your diabetes doctor twice a month, and you also have other diabetes-related health problems that affect your body. |
| 40% | You need to take insulin shots at least once every day to control your blood sugar, follow a special diet with restrictions on what you can eat, and limit or modify your daily activities because of your diabetes. This level means your diabetes requires daily medical management through injections and significantly affects how you live your life. |
| 20% | You need to take at least one insulin shot every day and follow a special diet to control your diabetes, OR you take diabetes pills (oral hypoglycemic agents - medications like metformin or glipizide that help lower blood sugar) along with following a restricted diet. Either of these treatment combinations shows your diabetes requires daily medication management beyond just diet and exercise alone. |
| 10% | You can control your diabetes just by following a special diet without needing any medications like insulin or pills. Your blood sugar levels stay within acceptable ranges as long as you stick to eating the right foods and avoiding others, but you don't require any medical treatment beyond dietary changes. |
Do's and Don'ts
Every item below comes from a pattern in the decisions on this pairing, not from general claim advice.
- Get a private opinion that discusses medical literature and explains how it applies specifically to your own history, not just the general population.
- Ask the examiner to address both causation and aggravation separately, since the Board has found opinions inadequate when they only cover one.
- Submit medical literature alongside a doctor's opinion that applies it to your case, since literature alone tends to get little weight.
- If you have obesity connected to a service-connected condition, ask the opinion to explain that obesity as the link between the service-connected condition and your diabetes.
- Report your onset of symptoms and any doctor's statements you remember at a hearing, since the Board has treated that testimony as competent and probative evidence.
- Don't rely on an opinion that only says there is "insufficient medical literature" without discussing your own facts, the Board has called that rationale inadequate on its own.
- Don't submit a medical article by itself with no doctor's opinion applying it to your case, the Board has given standalone articles low weight.
- Don't expect a conclusory statement like "his back limited his movement, which led to diabetes" to carry weight without an explanation of the mechanism.
- Don't assume aggravation is covered just because causation was addressed, the Board has sent claims back or ruled against them when aggravation was never analyzed.
- Don't ignore the timeline, the Board has weighed heavily against aggravation claims when the diabetes was diagnosed before the sleep apnea.
Quick Checklist Before You File
- Service connection already in place for Sleep Apnea, and a current medical diagnosis of type 2 diabetes.
- Diagnostic testing, imaging, or clinical records documenting the type 2 diabetes, whatever your provider used to diagnose and track it.
- A nexus opinion, whenever possible from a doctor familiar with type 2 diabetes, stating it is at least as likely as not caused or aggravated by the sleep apnea, and naming the mechanism rather than just the conclusion.
- Lay statements: spouse, family, friends, or battle buddies describing what they've witnessed or noticed.
- Your STRs and any VA opinions already in the file on either condition. If a VA opinion already went against you, your submitted opinion or statement should address its specific reasoning.
For the mechanics of filing itself, see the Standard Claim Guide and the Fully Developed Claim Guide.
The Claims Process, Step by Step
A secondary claim moves through the same pipeline as any other. Understanding who does what helps you know who to contact and what to expect.
- You file the claim, naming Sleep Apnea as the service-connected primary and type 2 diabetes as secondary. Directly with VA, through VA.gov, or with an accredited representative's help.
- VA assigns a Veteran Service Representative (VSR) to develop the claim: gather your service treatment records, VA and private medical records, and order a C&P exam if needed.
- The C&P exam is conducted, usually with the examiner asked to address the specific secondary theory (causation and aggravation both).
- The file goes to a Rating Veteran Service Representative (RVSR), the "rater," who weighs the medical evidence and decides service connection and, if granted, the rating percentage.
- VA issues the decision letter stating the outcome and the reasoning.
- If denied or under-rated, you choose an appeal lane, Supplemental Claim, Higher-Level Review, or a Board appeal, covered below.
Who's who: VSO vs. VSR vs. Rater vs. C&P Examiner
Your VSO
An accredited representative, agent, or attorney. Not a VA employee. Helps prepare and file, and can represent you on appeal. Has no authority to decide your claim.
VSR
VA staff who develops the claim: gathers records and schedules the exam. Does not decide the rating.
Rater (RVSR)
VA staff who reviews the complete file and makes the actual decision on service connection and percentage.
C&P Examiner
Conducts the exam and, where asked, gives a nexus opinion. Does not decide the claim, but the opinion's reasoning and legal framing carry real weight.
For the full walkthrough, see Inside Your Claim and Claim Stages.
DBQs and Your C&P Exam
A Disability Benefits Questionnaire (DBQ) is the standardized form the examiner completes for your condition. See the DBQ Guide for how these forms work and whether a private DBQ from your own doctor can be submitted instead of relying solely on a VA exam. For what to expect and how to prepare, see the C&P Exam Prep Guide, and be specific about how your type 2 diabetes symptoms relate to your sleep apnea timeline, treatment, and any aggravation, that is the detail a nexus opinion relies on.
Reading Your Decision Letter, and What to Do If Denied
Your decision letter has a narrative "reasons and bases" section and a codesheet with the rating and effective date. See the Reading Your Decision Letter Guide or use the Letter Interpreter tool to decode your own letter. If denied, you have three main lanes:
- Supplemental Claim: refile with new and relevant evidence, such as a nexus opinion that addresses the mechanism and the specific VA rationale you're rebutting. See Supplemental Claim Guide.
- Higher-Level Review (HLR): a senior reviewer looks at the same evidence again, useful if the denial rested on a legal error. See HLR Guide.
- Board Appeal: your case goes to a Veterans Law Judge, with a direct review, evidence, or hearing docket. See Board Appeal Guide.
Not sure which lane fits? See the Appeals decision guide for a side-by-side comparison.
After You Win: Maintaining Your Rating
Keep documentation of ongoing treatment, follow-up evaluations, and any updated diagnostic testing for your type 2 diabetes on file, this protects you if VA schedules a future reexamination. See Protect Your Rating for when a rating becomes protected and Future Reexaminations for what triggers one. If your type 2 diabetes worsens, see the Rating Increase Guide.
Frequently Asked Questions
Does Sleep Apnea have to be highly rated to support a type 2 diabetes secondary claim?
No. 38 CFR 3.310 looks at whether the service-connected Sleep Apnea caused or aggravated the type 2 diabetes, not at how severe the Sleep Apnea rating is. Even a 0% service-connected primary can anchor a secondary claim.
What do the percentages on this page mean?
They are the historical outcomes of 198 published Board decisions on this exact pairing: 40% granted, 16% denied, 43% remanded. They describe decided appeals already on record. They do not predict what would happen in any individual case.
RateMyVSO. Educational resource. Not affiliated with the U.S. Department of Veterans Affairs. Not legal advice. All RateMyVSO tools are free. Find a VSO representative for personalized guidance.