Arterial hypertension in obesity: relationships with hormone and anthropometric parameters

BACKGROUND: Obesity has been recognized as an independent risk factor for arterial hypertension. DESIGN: This study was addressed to identify parameters predictive of 24-h mean systolic and/or diastolic blood pressure levels in obesity. METHODS: A cohort of 180 euthyroid overweight and obese patients, 79 women and 101 men, aged 20-63 years, normotensive (n = 62) or with recently developed hypertension (n = 118), and never treated with antihypertensive drugs, was examined. Waist circumference, fasting insulin, thyroid stimulating hormone (TSH), free thyroxine (FT) FT(3), FT(4), glucose, and lipid (cholesterol, high-density lipoprotein cholesterol and triglyceride) serum concentrations, and 24-h urinary aldosterone and catecholamines were measured. Ambulatory blood pressure monitoring (ABPM) was performed and hypertension was confirmed when 24-h mean systolic blood pressure was ≥125 mmHg and/or 24-h mean diastolic blood pressure was ≥80 mmHg, according to the 2007 European Society of Hypertension and European Society of Cardiology Practice Guidelines for the Management of Arterial Hypertension. RESULTS: 24-h noradrenaline (p < 0.01) and adrenaline (p < 0.05) levels were higher in hypertensive than in normotensive subjects. The odds ratio (OR) was determined by several univariate and multivariate logistic regression analyses to evaluate the predictive factors of high 24-h blood pressure mean values. When subjects with high systolic and/or high diastolic blood pressure levels (n = 118) were compared to individuals with normal systolic and diastolic blood pressure levels (n = 62), multivariate analysis showed an independent association of hypertension with male gender and 24-h noradrenaline levels. When subjects with high systolic blood pressure levels (n = 108) were compared with those with normal systolic blood pressure levels (n = 72), multivariate analysis showed an independent association of high systolic blood pressure with noradrenaline levels. Lastly, when subjects with high diastolic blood pressure levels (n = 87) were compared with those with normal diastolic blood pressure levels (n = 93), multivariate analysis showed an independent negative association between high diastolic blood pressure and body mass index. CONCLUSIONS: the present study shows that diastolic blood pressure is independently and negatively associated with body mass index in normotensive or with recently discovered hypertension overweight and obese subjects, and never treated with antihypertensive drugs. These results suggest that obesity per se is responsible for a decrease in diastolic blood pressure before hypertensive state becomes stable. This study also confirms that male gender and daily noradrenaline production contribute to hypertension, and to higher systolic blood pressure levels in particular.