DIFFERENCES IN INSULIN AND SYMPATHETIC RESPONSES TO GLUCOSE-INGESTIONDUE TO FAMILY HISTORY OF HYPERTENSION

To evaluate the relationship of metabolic and neural factors in famili al hypertension, we examined blood pressure (BP), blood glucose, and p lasma insulin and norepinephrine (NE) levels before and every 30 min f or 120 min after glucose ingestion in six groups with 20 subjects each : normotensive subjects (NT) with and without a family history of hype rtension; borderline hypertensive patients (BHT) with and without a fa mily history of hypertension; and established hypertensive patients (E H) with and without a family history of hypertension. The changes in b lood glucose were similar in the six groups, In the subjects with a po sitive family history of hypertension regardless of BP levels, the bas al levels and changes in insulin levels after glucose ingestion were s ignificantly greater than those in the subjects without a family histo ry of hypertension (F = 13.32, P = .0001). In BHT and EH subjects, reg ardless of family history, changes in insulin were greater than in NT (F = 16.00, P = .0001). Basal levels and changes in plasma NE were hig her in BHT and EH (F = 26.55, P = .0001) than NT and changes in plasma NE were greater in subjects with a family history than those in subje cts without a family history (F = 18.32, P = .0001). Thus, abnormal in sulin and NE responses to glucose appear to aggregate in subjects with a history of familial hypertension, regardless of the level of BP. Fu rthermore, the ratio of Delta NE/Delta insulin (changes from basal to peak) in NT and BHT, and in subjects with a family history were signif icantly greater than in EH and in subjects without a family history. T hus, we demonstrated that concomitant abnormalities in the glucose-ins ulin regulatory system and the sympathetic nervous system characterize the early phase in the development of hypertension and these abnormal ities have an apparent genetic basis.