Relationship of insulin resistance and hyperinsulinemia to blood pressure during pregnancy.

The purpose of our study was to examine the relationship between insulin resistance and blood pressure during pregnancy and to determine to what extent insulin resistance is related to the subsequent development of pregnancy-induced hypertension. The study population consisted of 292 women who had serum insulin, glucose and insulin-glucose ratios determined at 26-28 weeks gestation in a fasting state and 1 hr after a 50-g oral glucose challenge. These were compared with blood pressures at 26-28 weeks gestation and in the late third trimester. A statistically significant correlation exists overall between (1) blood pressure at 26-28 weeks gestation and both fasting insulin and insulin-glucose ratios, as well as (2) systolic blood pressure at term and fasting insulin levels. However, when controlled for confounding variables including body mass index, race and age, no statistically significant relationship remained. The metabolic variables in patients with pregnancy-induced hypertension were not statistically different from the normotensive patients. In conclusion, this study demonstrates that insulin resistance and hyperinsulinemia are not major determinants of blood pressure during pregnancy.