Epidemiologic studies have shown that healthy offspring of hypertensive patients exhibit many features of the metabolic syndrome, such as hyperinsulinemia, insulin resistance, and lipid disorders. Patients with essential hypertension have reduced numbers of insulin receptors. The aim of this study was to examine whether the number of insulin receptors is reduced in the erythrocytes of healthy offspring of hypertensive patients in comparison to the offspring of healthy normotensive subjects. The study population consisted of 25 healthy offspring of patients with essential hypertension (group A) and 28 healthy offspring of healthy normotensive individuals (group B). The two groups were matched for sex, age, and body mass index. Systolic blood pressure (SBP) and diastolic blood pressure (DBP), resting heart rate (HR), plasma insulin levels, and human insulin receptor (hINR) number in erythrocytes were determined in each participant. Mean SBP, DBP, and resting HR were significantly higher in group A than in group B (121 +/- 13 v 110 +/- 10 mm Hg, 78 +/- 6 v 73 +/- 8 mm Hg, and 76 +/- 4 v 72 +/- 6 beats/min; P < .01, P < .05, and P < .01, respectively). Plasma insulin levels were significantly higher, whereas hINR density was significantly lower, in group A than in group B (21 +/- 7 v 15 +/- 6 pIU/mL, P < .01, and 5.6 +/- 1.4 v 6.8 +/- 1.3 receptors x 10(3)/red cell, P < .01, respectively). Our findings suggest that increased SBP, DBP, HR, plasma insulin levels, and decreased erythrocyte hINR density preexist in healthy offspring of patients with essential hypertension.