HEREDITY AND OBESITY-ASSOCIATED HYPERTENSION - IMPACT OF HORMONAL CHARACTERISTICS AND LEFT-VENTRICULAR MASS

Objectives: To investigate the influence of heredity on obesity-associ ated hypertension, we evaluated casual and 24-h blood pressure, left v entricular mass and some metabolic and hormonal measurements in normot ensive obese subjects. Design: Healthy, normotensive obese subjects (n = 81) with positive or negative family history of hypertension were s tudied. Both groups were also subdivided according to a positive or a negative family history of obesity. Accordingly, 45 obese subjects had a positive family history of hypertension, 25 of these having a posit ive (subgroup A) and 20 having a negative family history of obesity (s ubgroup B). The other 36 obese subjects had a negative family history of hypertension, 19 of these having a positive (subgroup C) and 17 hav ing a negative family history of obesity (subgroup D). Methods: Casual and 24-h systolic (SBP), diastolic (DBP) and mean blood pressure (MBP ) were evaluated. Serum fasting blood sugar, total cholesterol and tri glycerides levels, urinary excretion of sodium, immunoreactive fasting insulin, plasma ANF levels, plasma renin activity (PRA), plasma aldos terone level, plasma adrenaline and noradrenaline levels and echocardi ographic total left ventricular mass (LVM) and LVM:height ratio were a lso calculated. Results: Twenty-four-hour DBP, 24-h MBP, LVM, LVM:heig ht ratio, total cholesterol and PRA values were significantly higher i n normotensive obese offspring of hypertensive parents than in obese o ffspring of normotensive parents. Twenty-four-hour DBP and MBP, LVM, L VM:height ratio, insulin level, insulin:glucose ratio and PRA were sig nificantly higher in subgroup A than in subgroup B. Fasting blood suga r level, 24-h DBP and MBP, insulin level, insulin:glucose ratio, PRA, noradrenaline, adrenaline and plasma aldosterone levels were significa ntly higher in subgroup C than in subgroup D. Multivariate analysis al so indicated that 24-h MBP and PRA levels were significantly influence d by the association between a positive family history of hypertension and obesity. Conclusions: The present results suggest that a family h istory of obesity might increase the risk of developing hypertension i n obese subjects. An elevated PRA may precede the development of hyper tension in obese subjects who are at risk for developing hypertension.