U-shaped association between dietary calcium density intake during adolescence and hypertension in adulthood-a 20-y longitudinal nationwide study in China

Background and aims We assessed longitudinal association between calcium intake during adolescence and hypertension in adulthood. Methods and results Longitudinal study data of 1611 participants from the China Health and Nutrition Survey during 1991-2011 were used. On average they were followed for 11.4 years. Dietary calcium intake during adolescence was assessed based on three 24-hour dietary recalls collected in each visit/survey between 1991 and 2009 (seven waves). The intake was recoded into quartiles. Cumulative mean±SD calcium intake was 199.9±144.8 mg/1000 kcal/day during adolescence. In total 102 participants had hypertension in adulthood (97 men and 5 women). There was a clear U-shaped association between adolescence calcium intake quartiles and adulthood hypertension: across the quartiles, hypertension prevalence was 6.7%, 4.0%, 5.2% and 9.5%, respectively. After adjustment for potential confounders including weight status and dietary pattern, odds ratios (OR, 95%CI) for hypertension were 2.32 (95%CI 1.07-5.00) for lowest quartile, 1.00 (reference), 1.34 (95%CI 0.61-2.97), and 3.10 (95%CI 1.49-6.46) across the quartiles. Conclusions Lower or higher calcium intake during adolescence was associated with hypertension in adulthood independent of weight status and dietary pattern.