Microalbuminuria in never-treated hypertensives: lack of relationship to hyperinsulinemia and genetic predisposition to hypertension

We evaluated the relationship of microalbuminuria to hyperinsulinemia and family history of hypertension in 92 never-treated essential hypertensives (mean 24-h blood pressure >140 or 90 mm Hg), with positive (F+) or negative (F−) family history of hypertension: 31 had microalbuminuria (MA+) (urinary albumin excretion [UAE], 30 to 300 mg/24 h) and 61 had normal (<30 mg/24 h) UAE (MA−). Glucose and insulin values before and 30, 60, 90, and 120 min after an oral glucose load were measured together with an index of peripheral insulin activity (104/insulin × glucose values at glucose peak). Subjects with and without microalbuminuria did not differ with regard to age, sex, body mass index, and 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic blood pressure were significantly higher in MA+ than MA− patients. The prevalence of positive family history of hypertension was similar between MA+ and MA−, as were fasting and stimulated glucose and insulin values and the index of peripheral insulin activity. Subdividing the patients on the basis of family history of hypertension (59 F+, 33 F−) UAE was not significantly different between F+ and F−. UAE did not correlate with glucose and insulin parameters. From our results, in never-treated hypertensives, microalbuminuria is associated with higher blood pressure values, but is related neither to genetic predisposition to hypertension, nor to hyperinsulinemia; therefore, impaired insulin sensitivity and microalbuminuria are two components of the hypertensive syndrome, largely independent of each other.