Association of serum calcium and hypertension among adolescents aged 12-17 years in the rural area of Northeast China.

Calcium plays an important role in regulating body homeostasis. Several studies have reported the association between serum calcium and cardiovascular disease in adults. However, studies assessing the relationship between serum calcium and hypertension were limited, especially in subject populations of adolescents. The aim of the present study was to examine the association of serum calcium levels and blood pressure levels among adolescents in the rural area of Northeast China. A total of 2,023 students participated in this study, including 894 boys and 1,129 girls, aged from 12 to 17 years old. We measured the body weight, height, systolic blood pressure (SBP), diastolic blood pressure (DBP), and serum calcium concentrations of all eligible subjects, and the body mass index (BMI) was calculated from body weight and height. Childhood hypertension was defined as SBP and/or DBP ≥95th percentile for age and gender. According to the results of multivariable linear and logistic regression analysis, we found that higher serum calcium levels were positively associated with childhood hypertension. In comparison with serum calcium levels ≤2.37 mmol/L, the multivariable odds ratio (95 % confidence interval) of hypertension among adolescents with serum calcium levels ≥2.53 mmol/L was 1.89 (1.41-2.53; P trend < 0.001). In addition, higher serum calcium levels were also positively associated with average difference in SBP and DBP; the average differences (95 % confidence interval) were 4.22 (2.74-5.83; P trend < 0.001) and 2.23(1.00-3.46; P trend < 0.001), respectively. In conclusion, higher serum calcium concentrations were found to have an association with higher blood pressure levels and higher prevalence of hypertension in the young population.