Diabetes Secondary to Hypertension

If your hypertension is service connected and you were later diagnosed with diabetes, you can claim the diabetes as secondary to the hypertension. I want to be plain about why this claim is harder than most. The two conditions often show up together, but research does not show that high blood pressure itself causes type 2 diabetes. What it does support is narrower: some blood pressure medicines raise blood sugar and the risk of new diabetes. That medicine route, and aggravation, are usually where this claim is won. If you served where VA presumes herbicide exposure, the Agent Orange presumption is often better than either.

Can hypertension cause diabetes?

People with high blood pressure develop diabetes more often. Whether the blood pressure itself is the cause is a separate question, and the research splits on it.

• In health records of 4.1 million adults with no diabetes or cardiovascular disease at the start (Emdin and colleagues, Journal of the American College of Cardiology, 2015), systolic pressure 20 mm Hg higher was tied to a 58% higher risk of new diabetes. The link grew weaker with age and with higher body mass index.
• A genetic study of 318,664 people of European descent in the UK Biobank (Sun and colleagues, Circulation Research, 2019) found that genetic risk for type 2 diabetes was tied to hypertension, but genetic risk for hypertension showed no relationship with type 2 diabetes (odds ratio 0.96). The authors concluded that the link from hypertension to diabetes is unlikely to be causal, while diabetes may cause hypertension.
• An earlier genetic study of 37,293 people with type 2 diabetes and 125,686 without it (Aikens and colleagues, Diabetes, 2017) found the opposite: each 1 mm Hg of genetically higher systolic pressure was tied to a 2% higher risk of type 2 diabetes.

So high blood pressure and type 2 diabetes travel together, and the genetic studies disagree about whether one causes the other. A claim that says only "my high blood pressure caused my diabetes" asks the examiner to accept the weakest version of the link. The stronger evidence is about treatment.

When blood pressure medicine is the link

Because a blood pressure medicine treats your service-connected hypertension, a medical opinion can tie the diabetes to the hypertension through its treatment. The research is strongest for beta blockers and thiazide diuretics.

• A meta-analysis of 12 trials with 94,492 patients with hypertension (Bangalore and colleagues, American Journal of Cardiology, 2007) found that beta blockers used as first treatment raised the risk of new diabetes by 22% compared with blood pressure medicines other than diuretics. The risk was greater with atenolol, in older patients, and with longer time on beta blockers.
• In the Atherosclerosis Risk in Communities study of 12,550 adults aged 45 to 64 without diabetes (Gress and colleagues, New England Journal of Medicine, 2000), people with hypertension who took beta blockers had a 28% higher risk of diabetes than people with hypertension who took no medicine. People taking thiazide diuretics, ACE inhibitors or calcium channel blockers were not at higher risk.
• In the ALLHAT trial (Barzilay and colleagues, Archives of Internal Medicine, 2006), among participants without diabetes, fasting glucose rose more in two years with chlorthalidone, a thiazide-type diuretic (8.5 mg/dL), than with amlodipine (5.5) or lisinopril (3.5). The odds of new diabetes at two years were lower with lisinopril (0.55) and amlodipine (0.73) than with chlorthalidone.
• In the SHEP trial of 3,790 adults aged 60 or older with isolated systolic hypertension and no diabetes (Shafi and colleagues, Hypertension, 2008), chlorthalidone roughly doubled the adjusted risk of diabetes in the first year compared with placebo (hazard ratio 2.07). Falling potassium explained part of it. After the first year, chlorthalidone was not tied to a higher risk.
• A network meta-analysis of 22 trials with 143,153 participants (Elliott and Meyer, Lancet, 2007) ranked beta blockers and diuretics highest for new diabetes, and angiotensin receptor blockers and ACE inhibitors lowest.
• Dose matters for thiazides. A meta-analysis of 26 trials with 16,162 participants (Zhang and Zhao, Journal of Clinical Hypertension, 2016) found a small average rise in fasting glucose of 4.86 mg/dL. In the trials comparing thiazides with calcium channel blockers, 25 mg a day or less raised it 2.7 mg/dL, against 10.8 mg/dL at higher doses. A meta-analysis of low-dose thiazide trials (Mukete and Rosendorff, Journal of the American Society of Hypertension, 2013) concluded the glucose change did not appear to put patients at clinically significant risk.

So the drug, the dose and the dates matter, and so does timing. In SHEP, thiazide-related diabetes showed up in the first year, while the beta blocker risk in the 2007 review grew with time on the drug.

When your diabetes came first

If you had diabetes before the hypertension or before the medicine, causation will not fit, but aggravation may. In the GEMINI trial of 1,235 adults with hypertension and type 2 diabetes who were already taking an ACE inhibitor or angiotensin receptor blocker (Bakris and colleagues, JAMA, 2004), HbA1c rose 0.15% from baseline on metoprolol tartrate and did not change significantly on carvedilol. A meta-analysis of 13 trials with 720 patients with type 2 diabetes (Lin and colleagues, European Review for Medical and Pharmacological Sciences, 2016) found higher fasting glucose and HbA1c with hydrochlorothiazide. I did not find research showing that high blood pressure itself makes diabetes harder to control; the aggravation evidence is about the medicines.

How VA decides diabetes secondary to hypertension

Secondary service connection is in 38 CFR § 3.310. VA grants it in two ways.

• Caused by. Your service-connected hypertension, including the medicine prescribed for it, caused the diabetes, at least as likely as not.
• Aggravated by. Your diabetes is aggravated by your service-connected hypertension, meaning it would be less severe but for the hypertension (M21-1 V.ii.2.D). VA rates only the part above the baseline level of the diabetes before the aggravation, so the opinion should describe that baseline.

The claim needs a diabetes diagnosis that names the type, service-connected hypertension, and a medical opinion linking the two with reasoning. For the medicine route, add pharmacy records showing each drug, dose and date range, plus glucose and HbA1c results from before and after.

When Agent Orange is the better route

Before you build a secondary claim, check the herbicide presumption. The list in 38 CFR § 3.309(e) includes "Type 2 diabetes (also known as Type II diabetes mellitus or adult-onset diabetes)." Under § 3.307(a)(6), it must reach 10 percent or more at any time after service, and qualifying service includes the Republic of Vietnam, with its offshore waters, from January 9, 1962, to May 7, 1975, plus certain service near the Korean DMZ and on C-123 aircraft. The diabetes VA rating page and the presumptive conditions tool cover who qualifies. VA presumes the link unless affirmative evidence rebuts it (§ 3.307(d)).

If you qualify, the presumption is usually stronger: you need no nexus opinion, and unlike an aggravation grant, VA rates the whole condition. The 2019 genetic study also supports diabetes raising blood pressure more than the reverse, so once diabetes is service connected, hypertension secondary to diabetes may be the stronger pairing. The hypertension VA rating page explains the Agent Orange route for high blood pressure itself.

VA rating for diabetes secondary to hypertension

Diabetes secondary to hypertension is rated like any diabetes, under Diagnostic Code 7913 in 38 CFR § 4.119.

• 100%: "Requiring more than one daily injection of insulin, restricted diet, and regulation of activities (avoidance of strenuous occupational and recreational activities) with episodes of ketoacidosis or hypoglycemic reactions requiring at least three hospitalizations per year or weekly visits to a diabetic care provider, plus either progressive loss of weight and strength or complications that would be compensable if separately evaluated"
• 60%: "Requiring one or more daily injection of insulin, restricted diet, and regulation of activities with episodes of ketoacidosis or hypoglycemic reactions requiring one or two hospitalizations per year or twice a month visits to a diabetic care provider, plus complications that would not be compensable if separately evaluated"
• 40%: "Requiring one or more daily injection of insulin, restricted diet, and regulation of activities"
• 20%: "Requiring one or more daily injection of insulin and restricted diet, or; oral hypoglycemic agent and restricted diet"
• 10%: "Manageable by restricted diet only"

Note (1) to DC 7913 says compensable complications of diabetes are evaluated separately unless they are part of the criteria for 100 percent. The diabetes VA rating page explains the "regulation of activities" requirement that separates 20 from 40 percent, and the diabetes secondary conditions page covers complications you can claim once diabetes is service connected.

VA rates diabetes separately from hypertension, and the ratings combine under 38 CFR § 4.25, larger rating first. A 20 percent diabetes rating and a 10 percent hypertension rating combine to 28, because the 10 percent takes its share of the remaining 80. VA rounds 28 to 30 percent.

An aggravation grant works differently. VA rates only the part above the baseline, and the baseline has to be shown by medical evidence. The text of § 3.310(b) still mentions deducting natural progress, but VA's current manual (M21-1 V.ii.2.D) no longer applies that part. If your diabetes was manageable by restricted diet only (10 percent) before a blood pressure medicine and now needs an oral agent and a restricted diet (20 percent), the aggravation grant is the 10 points above the baseline.

The C&P exam for diabetes secondary to hypertension

The examiner is asked whether your diabetes is at least as likely as not caused by your hypertension and, separately, whether the hypertension aggravated it. An opinion that answers only the first question is inadequate under El-Amin v. Shinseki (2013).

The examiner looks at these records.

• When the diabetes was diagnosed compared with the hypertension diagnosis and the start of each blood pressure medicine
• Your fasting glucose and HbA1c results before and after each medicine started
• Your potassium results if you took a thiazide, since falling potassium explained part of the thiazide risk in SHEP
• Other risk factors, such as weight, age and family history

Unfavorable opinions usually go wrong in one of three ways: they say high blood pressure does not cause diabetes and stop, without asking about the medicine or aggravation; they blame weight or age and ignore a drug known to raise blood sugar; or they cite the one study that found no extra thiazide risk and ignore the trials that did. The Board section below shows how the Board ruled on these appeals. C&P exam prep can help you get ready.

Why diabetes secondary to hypertension claims get denied

These gaps lead to denials.

• The claim rests on high blood pressure alone, with nothing about the medicine.
• The file has no pharmacy record showing the drug, the dose and the dates.
• The diabetes was diagnosed before the medicine started, and no opinion addresses aggravation.
• An opinion answers causation but not aggravation.
• An aggravation opinion has no baseline, such as earlier glucose results or the treatment you needed before the worsening.

Nexus letter for diabetes secondary to hypertension

A strong nexus letter for this claim does six things.

1. States that the doctor reviewed your blood pressure history, medication list with doses and dates, and glucose and HbA1c results.
2. Names the route: the hypertension itself, a specific blood pressure medicine, or both.
3. Gives an opinion on causation: your type 2 diabetes is at least as likely as not caused by your service-connected hypertension, including its treatment.
4. Gives a separate opinion on aggravation: your diabetes is aggravated by your service-connected hypertension, meaning it would be less severe but for the hypertension, and describes the baseline, such as the treatment your diabetes needed before the worsening.
5. Explains the reasoning and cites the research, including the genetic study that found the link from hypertension to diabetes unlikely to be causal.
6. Deals with weight, age and family history directly.

Where these opinions break down is predictable: a conclusion with no reasoning, no drug named, a timeline that does not match the research, or silence on aggravation. Raven Nexus can organize your records and the research into a draft for your doctor to review.

Questions veterans ask about diabetes secondary to hypertension

Can diabetes be secondary to hypertension for VA disability?

Yes, under 38 CFR § 3.310, when your service-connected hypertension or its treatment caused the diabetes or made it worse. The medicine route has the strongest research.

Can blood pressure medicine cause diabetes?

Some can raise the risk. Trials tie beta blockers and thiazide diuretics to more new diabetes than ACE inhibitors or angiotensin receptor blockers, and the thiazide effect is larger at higher doses.

What is the VA rating for diabetes secondary to hypertension?

The same as any diabetes under Diagnostic Code 7913: 10, 20, 40, 60 or 100 percent, combined with your hypertension rating under 38 CFR § 4.25.

Is the Agent Orange presumption better than a secondary claim?

For a veteran who qualifies, usually yes: no nexus opinion is needed, and VA rates the whole condition.

Can I claim hypertension secondary to diabetes instead?

If your diabetes is service connected, yes, and the 2019 genetic study supports that direction more than the reverse. The hypertension secondary conditions page lists other claims built on high blood pressure.

Sources

• 38 CFR § 3.310, secondary service connection, including § 3.310(b) on the baseline; M21-1 V.ii.2.D, aggravation of a nonservice-connected disability by a service-connected one.
• 38 CFR § 4.119, Diagnostic Code 7913, diabetes mellitus, and its notes; 38 CFR § 4.25, combined ratings table.
• 38 CFR § 3.309(e), diseases associated with herbicide exposure; 38 CFR § 3.307(a)(6) and (d).
• El-Amin v. Shinseki, 26 Vet. App. 136 (2013), an opinion must address aggravation.
• Emdin CA, Anderson SG, Woodward M, Rahimi K. Usual Blood Pressure and Risk of New-Onset Diabetes: Evidence From 4.1 Million Adults and a Meta-Analysis of Prospective Studies. Journal of the American College of Cardiology. 2015;66(14):1552-1562. PMID 26429079.
• Sun D, Zhou T, Heianza Y, et al. Type 2 Diabetes and Hypertension. Circulation Research. 2019;124(6):930-937. PMID 30646822.
• Aikens RC, Zhao W, Saleheen D, et al. Systolic Blood Pressure and Risk of Type 2 Diabetes: A Mendelian Randomization Study. Diabetes. 2017;66(2):543-550. PMID 27702834.
• Bangalore S, Parkar S, Grossman E, Messerli FH. A meta-analysis of 94,492 patients with hypertension treated with beta blockers to determine the risk of new-onset diabetes mellitus. American Journal of Cardiology. 2007;100(8):1254-1262. PMID 17920367.
• Gress TW, Nieto FJ, Shahar E, Wofford MR, Brancati FL. Hypertension and antihypertensive therapy as risk factors for type 2 diabetes mellitus. New England Journal of Medicine. 2000;342(13):905-912. PMID 10738048.
• Barzilay JI, Davis BR, Cutler JA, et al. Fasting glucose levels and incident diabetes mellitus in older nondiabetic adults randomized to receive 3 different classes of antihypertensive treatment: a report from ALLHAT. Archives of Internal Medicine. 2006;166(20):2191-2201. PMID 17101936.
• Shafi T, Appel LJ, Miller ER 3rd, Klag MJ, Parekh RS. Changes in serum potassium mediate thiazide-induced diabetes. Hypertension. 2008;52(6):1022-1029. PMID 18981326.
• Elliott WJ, Meyer PM. Incident diabetes in clinical trials of antihypertensive drugs: a network meta-analysis. Lancet. 2007;369(9557):201-207. PMID 17240286.
• Zhang X, Zhao Q. Association of Thiazide-Type Diuretics With Glycemic Changes in Hypertensive Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Clinical Trials. Journal of Clinical Hypertension. 2016;18(4):342-351. PMID 26395424.
• Mukete BN, Rosendorff C. Effects of low-dose thiazide diuretics on fasting plasma glucose and serum potassium: a meta-analysis. Journal of the American Society of Hypertension. 2013;7(6):454-466. PMID 23800570.
• Bakris GL, Fonseca V, Katholi RE, et al. Metabolic effects of carvedilol vs metoprolol in patients with type 2 diabetes mellitus and hypertension: a randomized controlled trial. JAMA. 2004;292(18):2227-2236. PMID 15536109.
• Lin JJ, Chang HC, Ku CT, Chen HY. Hydrochlorothiazide hypertension treatment induced metabolic effects in type 2 diabetes: a meta-analysis of parallel-design RCTs. European Review for Medical and Pharmacological Sciences. 2016;20(13):2926-2934. PMID 27424996.
• Board figures on this page: Claim Raven's read of every Board decision from 2021 to 2026 that it holds, and of every decision since 1992 for the longer view.