Angiotensin I converting enzyme gene polymorphism and insulin resistance in patients with hypertension.

BACKGROUND: The homozygote deletion (DD) genotype of the angiotensin I converting enzyme (ACE) gene has been shown to be associated with an increased risk of coronary heart disease independent of other risk factors. OBJECTIVE: To investigate the possible association of the insertion/deletion (I/D) polymorphism of the ACE gene with insulin resistance in a Chinese population with and without hypertension. SUBJECTS AND METHODS: The I/D polymorphism of the ACE gene was determined for 361 Chinese including 148 women and 96 men with normal blood pressures and 64 male and 53 female patients with mild-to-moderate hypertension. Insulin resistance was estimated by the insulin suppression test and glucose intolerance evaluated with an oral glucose-tolerance test for all of the subjects. RESULTS: Three hypertensive subgroups with DD, DI and II genotypes having similar ages and body mass indexes presented insignificantly different degrees of glucose intolerance and insulin resistance both among men and among women. Similar results were found for normotensive subjects. In addition, ACE genotypes were not significant predictors of insulin resistance and glucose intolerance either among men or among women after adjustment for age, body mass index, and hypertension. CONCLUSION: The present data indicated that the I/D polymorphism of the ACE gene was not related to insulin resistance for Chinese hypertensive and normotensive subjects. The increased risk of coronary heart disease associated with the DD genotype need not be mediated through the mechanism of insulin resistance and glucose intolerance for Chinese patients with hypertension.