ABSTRACT
Objective: to assess the amount of salt intake among normotensive [NT] and prehypertensive [PHT] subjects and to determine whether the association between salt intake and blood pressure is correlated with body weight and waist circumference [WC] or is independent
Methods: a total of 806 NT and PHT subjects from Isfahan Healthy Heart Program [IHHP] were enrolled in the study. A standard questionnaire was used to assess sociodemographic characteristics. The amount of salt intake was measured by the 24-hour urine collection method. Blood pressure, height, weight, and WC were measured based on standard protocols
Results: the mean ages [+/- SD] of NT and PHT subjects were 35.9 [+/- 11.9] and 44.7 [+/- 12.5] years, respectively [P < 0.001]. The mean values of body mass index [BMI] and WC were greater among PHT than NT subjects [BMI: 27.9 +/- 3.8 vs. 25.1 +/- 4.3 kg/m2; P < 0.001 and WC: 90.2 +/- 8.6 vs. 81.2 +/- 11.2 cm; P < 0.001, respectively]. PHT subjects had higher amount of salt intake than NT ones [10.3 +/- 6.2 vs. 12.7 +/- 7.1 g/d, respectively; P = 0.003]. Odds ratio [OR] for being PHT increased significantly across the tertils of salt intake in crude model and sociodemographic- adjusted model. Further adjustment for BMI and WC values weakened the OR for being PHT and showed nonsignificant trend [OR [and 95% CI] for BMI across tertiles of salt intake: 1, 1.26 [0.59 2.69], 1.89 [0.93 3.81]; P = 0.063 and OR [and 95% CI] for WC across tertiles of salt intake: 1, 1.22 [0.58 2.57], 1.79[0.89 3.56]; P = 0.082]
Conclusion: the findings of this study suggest that the association between salt intake and blood pressure is related to body weight and WC