Dietary Intakes of Branched Chain Amino Acids and the Incidence of Hypertension: A Population-Based Prospective Cohort Study

Background: Dietary amino acids have been associated with blood pressure (BP) in previous studies; we conducted this study to examine the association between dietary branched chain amino acids (BCAAs) and the incidence of hypertension among participants of the Tehran Lipid and Glucose Study (TLGS). Methods: Analyses were conducted on 4,288 participants aged 20-70 years, who were free of hypertension at baseline (20082011) and were followed for 3 years (2011-2014) to ascertain incident hypertension. Dietary intakes of BCAAs including, valine, leucine, and isoleucine were collected at baseline using the food frequency questionnaire (FFQ). Odds ratio (OR) of hypertension were determined by logistic regression across quartiles of BCAAs, adjusted for sex, age, smoking status, physical activity, body mass index (BMI), diabetes, and some dietary factors. Results: The mean +/- standard deviation for age and BMI of participants (41.9% men) were 39.7 +/- 12.8 years and 26.9 +/- 4.6 kg/m(2), respectively. The median intakes of total BCAAs, valine, leucine, and isoleucine was 17.9, 5.5, 7.8, and 4.5 percentage of total amino acids intake, respectively. We documented 429 (10%) hypertension incident cases. The multivariable adjusted OR for the highest vs lowest quartiles of BCAAs was 1.54 (95% confidence interval (CI): 1.03-2.32; P for trend = 0.05); furthermore, the OR (95% CI) of hypertension for the highest vs the lowest quartile of valine was 1.61 (1.10-2.36; P for trend = 0.009) in the fully adjusted model. However, we found no significant association between leucine and isoleucine with incidence of hypertension. Conclusion: Findings indicated that higher BCAA intake, in particular valine, is associated with higher risk of incident hypertension.