Improvement of glucose tolerance and lowering of glycohemoglobin and serum lipid concentrations after discontinuation of antihypertensive drug therapy.

Diuretic-based antihypertensive drug therapy causes a disturbance in glucose tolerance and in serum lipid and lipoprotein concentrations. To determine the reversibility of the glucose intolerance and to identify mechanisms of the metabolic alterations, we examined a short glucose tolerance test and insulin, glycohemoglobin and lipid concentrations during the supervised withdrawal of long-term drug therapy in 35 patients with primary hypertension. An average of 7 weeks after stopping drugs, glucose tolerance and glycohemoglobin improved, total cholesterol decreased 18 mg/dl, triglyceride decreased 27 mg/dl, and the ratio of total to high-density lipoprotein cholesterol decreased (p less than 0.01 for all variables vs treatment values). The changes in lipid concentrations from the treated to untreated state correlated with the changes in glycohemoglobin and indexes of glucose metabolism. The findings suggest that insulin resistance develops during drug therapy and disturbs both glucose and lipid metabolism. Attention to these alterations may provide directions for further control of atherosclerotic complications during the treatment of hypertension.