[Blood pressure levels in young students. Correlation between body mass and metabolic and hemodynamic factors].

Blood pressure (BP) levels were measured in 450 students (mean age 20.8 +/- .11 years old) and were correlated with different parameters. Prevalence of arterial hypertension was, according to the JNC-V, 13% in males and 3% in females. The correlations between Body Mass Index (BMI) and BP levels were statistically significant either in males and females. Mean BP (MBP) increased 1.17 mmHg per unit of increase of BMI in males and 0.97 mmHg in females. According to the BP levels proposed by the JNC-V the male individuals were classified in three groups: optimal BP (OBP), high normal BP (HNBP) and hypertensives stage 1 (Hypert.). These groups had different BMI; OBP: 22.74 +/- 2; HNBP 24.4 +/- 0.48; Hypert. 25.06 +/- 0.66 kg/m2 (P < 0.05 Hypert. and HNBP as regards PAO; HNBP and Hypert. were not statistically different). Samples of each of these groups were taken in order to analyze other parameters such as: cardiac index (CI), total peripheral resistance (TPR), plasma glucose, plasma insulin, glucose/insulin ratio and intracellular pH in platelets. No significant differences were found in the three groups as regards plasma glucose, plasma insulin and glucose/insulin ratio. The different BP levels among the groups were due to an increase in CI: OBP 3.25 +/- 0.13; HNBP 3.76 +/- 0.2; Hypert. 4.76 +/- 36 ml/min/m2 (P < 0.05) but with TPR numerically "normal": OBP: 2139 +/- 106; HNBP 2170 +/- 114; Hypert. 1858 +/- 146 dynes sec. cm-5 m2 (NS). The intracellular pH in platelets was: 7.15 +/- 0.07 in the OBP, 7.21 +/- 0.05 in the HNBP and 7.33 +/- 0.04 in the Hypert. (P < 0.05 in the Hypert. as regards the PAO). The increase of the pHi in the Hypert. suggests hyperactive Na+/H+ exchanger.