Thiazide diuretics (TD) are recommended as first-line therapy in uncomplicated hypertension by several professional organizations. However, they also may pose a risk of glucose metabolism abnormalities in certain individuals. Early studies showed TD cause a small increase in fasting glucose. These effects may be related to exacerbation of insulin resistance as insulin blood levels increased. It could be postulated that long-term use may result in a higher risk of developing diabetes. This was not seen in the Systolic Hypertension in the Elderly study which used low doses of chlorthalidone but an increase in the odds of developing diabetes was demonstrated for chlorthalidone in comparison to lisinopril or amlodipine in the ALLHAT study. Nonetheless, in ALLHAT there was no increased risk of adverse cardiovascular outcomes. In addition, use of chlorthalidone in the ALLHAT study in patients with pre-existing diabetes maintained the same advantage in lower stroke rate versus lisinopril and lower heart failure rate versus amlodipine or lisinopril. Other factors that may play a role in thiazide-induced glucose elevation are potassium levels and weight. In a meta-analysis of 59 trials a correlation existed for lower potassium levels and higher fasting glucose. Epidemiological studies suggest that elevated BMI and the level of pre-thiazide fasting glucose predict glucose elevation and new onset diabetes after thiazide therapy. Patients with a BMI over 32.3 kg/m2 had a 6.5% risk of developing diabetes. Whether co-administration of a thiazide diuretic with other classes of antihypertensives modulates the glucose alteration remains unknown. Studies suggest combination with valsartan may reduce the effect perhaps by conserving potassium. Practical implications of these observations would suggest reserving thiazide diuretics to later stages in treatment for patients who are obese, particularly if they have fasting blood glucoses in the pre-diabetic range. However, for the majority of patients thiazide diuretics remain an excellent choice given their long track record of safety and beneficial long-term cardiovascular outcomes.
|Translated title of the contribution||Glucose metabolism in hypertension patients|
|Number of pages||4|
|State||Published - Oct 1 2016|
- Thiazide diuretics
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