Purpose: Essential hypertension is, in some patients, complicated by impairment of insulin-mediated glucose disposal and hyperinsulinemia. Whether this metabolic disturbance is a consequence of the hypertensive process or whether it may precede, and thus possibly promote, the development of hypertension has been unknown.
Subjects and methods: Searching for hereditary or familial defects in hypertension-prone humans, we prospectively investigated insulin sensitivity, plasma insulin and glucose, and serum lipoproteins in normotensive offspring of essential hypertensive as compared with age- and body habitus-matched offspring of normotensive families.
Results: Compared with 78 control subjects, 70 offspring of essential hypertensive parents had similar age (mean +/- SEM: 24 +/- 1 versus 24 +/- 1 years, respectively) and body mass index (22.3 +/- 0.2 versus 22.4 +/- 0.2 kg/m2), a blood pressure of 127/77 +/- 1/1 versus 123/76 +/- 1/1 mm Hg (p less than 0.05 for systolic), and significantly elevated (p less than 0.01 to 0.001) fasting plasma insulin levels (9.9 +/- 0.3 versus 8.6 +/- 0.3 microU/mL), serum total triglycerides (1.03 +/- 0.06 versus 0.83 +/- 0.03 mmol/L), total cholesterol (4.37 +/- 0.08 versus 3.93 +/- 0.07 mmol/L), low-density lipoprotein cholesterol (2.45 +/- 0.08 versus 2.14 +/- 0.07 mmol/L), and total/high-density lipoprotein cholesterol ratio (4.3 +/- 0.1 versus 3.7 +/- 0.1). Insulin sensitivity was lower (9.4 +/- 0.7 versus 13.2 +/- 1.1 x 10(-4) x minute-1/microU/mL, p less than 0.001), while post-glucose-load plasma insulin levels were higher (p less than 0.05) in the 41 offspring of essential hypertensive parents than in the 38 offspring of normotensive parents so investigated.
Conclusion: These findings demonstrate that young normotensive humans in apparently excellent health but with one essential hypertensive parent tend to have an impairment of insulin-mediated glucose disposal, hyperinsulinemia, and dyslipidemia. It follows that a familial trait for essential hypertension seems to coexist commonly with defects in carbohydrate and lipoprotein metabolism that can be detected before or at least at a very early stage of the development of high blood pressure as judged by resting blood pressure measurements.