Blood pressure predicts insulin requirement and exogenous insulin is associated with increased blood pressure in women with gestational diabetes mellitus.

Fifty gestational diabetic women were studied to determine the interaction of blood pressure, insulin resistance, and the effect of exogenous insulin on blood pressure response. Gestational diabetes was diagnosed according to the criteria affirmed by the Third International Workshop-Conference on Gestational Diabetes at 20 to 32 weeks' gestation. At diagnosis, all women were placed on a standard diet and performed glucose monitoring on rising and 1 hour after meals. The criteria for initiation of insulin included fasting whole blood finger stick glucose more than 90 mg/dL, ketonuria that could only be cleared by increasing carbohydrate to a level causing postprandial hyperglycemia, or postprandial glucose levels at 1 hour above 140 mg/dL. Of the initial cohort, 28 required insulin to maintain target glycemia. Within this group, there was a significant positive correlation between mean arterial pressures at initiation of therapy for gestational diabetes mellitus and insulin requirement quantified by the amount of insulin required to maintain euglycemia at term (r2 = 0.259; P = 0.006). The initiation of insulin was associated with a significant blood pressure increase in this group when compared with values prior to insulin administration or to values in the group treated with diet alone. These observations are consistent with an interaction of blood pressure and insulin resistance as reflected by insulin requirement in women with gestational diabetes mellitus.