From the Guidelines
Thiazide diuretics are contraindicated in people with diabetes due to their potential to worsen glycemic control and increase the risk of cardiovascular complications. The use of thiazide diuretics in diabetic patients can lead to decreased insulin secretion and increased insulin resistance, resulting in elevated blood glucose levels 1. Additionally, thiazides can cause hypokalemia, which further impairs insulin secretion, and may also increase cholesterol and triglyceride levels, exacerbating cardiovascular risk 1.
Key Considerations
- Thiazide diuretics can raise uric acid levels, potentially triggering gout attacks in diabetic patients 1.
- The American Diabetes Association guidelines recommend alternative antihypertensive medications, such as ACE inhibitors, ARBs, or calcium channel blockers, as first-line treatment for hypertension in patients with type 2 diabetes mellitus 1.
- If a thiazide diuretic must be used, lower doses are recommended with careful monitoring of blood glucose, electrolytes, and lipid profiles 1.
- Regular laboratory testing should be performed within 2-4 weeks of starting therapy and periodically thereafter to assess the impact of thiazide diuretics on glycemic control and cardiovascular risk factors.
Alternative Treatment Options
- ACE inhibitors or ARBs are preferred first-line treatment for hypertension in patients with type 2 diabetes mellitus due to their renoprotective effects and ability to reduce the risk of cardiovascular events 1.
- Calcium channel blockers, such as dihydropyridine agents, may also be used as alternative antihypertensive medications in diabetic patients 1.
- Mineralocorticoid receptor antagonists, such as spironolactone or eplerenone, can be effective antihypertensive agents and are important for morbidity and mortality reduction in patients with left ventricular dysfunction 1.
From the FDA Drug Label
WARNINGS ... Diabetes and Hypoglycemia: Latent diabetes mellitus may become manifest and diabetic patients given thiazides may require adjustment of their insulin dose. Thiazide diuretics, such as hydrochlorothiazide, are not strictly contraindicated for people with diabetes, but they may exacerbate the condition.
- Key points:
- Latent diabetes mellitus may become manifest
- Diabetic patients may require adjustment of their insulin dose 2
From the Research
Thiazide Diuretics and Diabetes
- Thiazide diuretics are not entirely contraindicated for people with diabetes, but their use has been challenged due to associated metabolic adverse events, including new-onset diabetes 3.
- The use of thiazides in patients with prediabetes or type 2 diabetes has been found to result in significant reduction in cardiovascular events, all-cause mortality, and hospitalization for heart failure compared to placebo 3.
- However, thiazide-type diuretics have been found to increase fasting plasma glucose compared with nonthiazide agents or placebo, with higher doses resulting in greater changes in fasting plasma glucose 4.
Glycemic Effects of Thiazide Diuretics
- Thiazide-type diuretics are associated with significant but small adverse glycemic effects in hypertensive patients, with lower doses resulting in less change in fasting plasma glucose 4.
- The combination of thiazides and loop diuretics has been found to improve blood pressure levels and decrease proteinuria in patients with type 2 diabetic kidney disease, without negatively affecting the change in estimated glomerular filtration rate 5.
Concurrent Use of Thiazide Diuretics and Statins
- The concurrent use of thiazide diuretics and statins in patients with diabetes has been found to be associated with diabetes progression, but with less kidney progression and cardiovascular outcomes, and no difference in mortality 6.
- Clinicians should closely monitor diabetes control when thiazides and statins are used concurrently 6.
Therapeutic Roles of Thiazides and Loop Diuretics
- Thiazides and loop diuretics may have a role in blood pressure control and renal protection against chronic kidney disease, although the evidence for their benefits is not yet conclusive 7.
- Recent data suggest that diuretics may be effective in lowering blood pressure and slowing the progression of kidney disease in patients with advanced chronic kidney disease 7.