Blood pressure and its associated factors among primary school children in suburban Selangor, Malaysia: A cross-sectional survey

BACKGROUND: Little is known about the relationship of blood pressure (BP) with adiposity indicators, dietary habits, physical activity, and sleep in school children in Malaysia. We aimed to study about the distribution of BP and its associated factors in primary school children.
MATERIALS AND METHODS: A survey was carried out on a random sample of 335 children in five primary schools. BP was measured with a mercury sphygmomanometer. Anthropometry was done by standard methods. Demographic information, dietary habits, physical activity, and duration of sleep were collected by interviews. World Health Organization classification based on body mass index (BMI) and waist circumference (WC) cut-offs were used to define overweight/obesity. Elevated BP was defined according to US reference standards.
RESULTS: A total 335 children (144 boys and 191 girls) were examined. Their mean age was 9.18 years (standard deviation [SD] = 0.28). Overall mean systolic blood pressure (SBP) and mean diastolic blood pressure (DBP) were 99.32 mmHg (SD = 10.79) and 67.11 mmHg (SD = 10.76), respectively. Mean BMI and WC were 16.39 (SD = 3.58) and 57.77 cm (SD = 8.98), respectively. The prevalence of pre-hypertension was 12.23% (95% confidence intervals [CIs] 8.73, 15.75) and hypertension was 13.4% (95% CIs 9.78, 17.09). Mean SBP and DBP was higher among overweight and obese children than normal children. By multivariate linear regression analyses, BMI (β = 0.250, P = 0.049) and WC (β = 0.308, P = 0.015) were positively associated with SBP; age (β = 0.111, P = 0.017), BMI (β = 0.320, P = 0.012) were positively associated with DBP but total (weekly) hours of sleep (β = -0.095, P = 0.037) was negatively associated with DBP.
CONCLUSION: BP was associated with BMI and WC. Health promotion activities should be initiated in primary schools.
KEYWORDS: Blood pressure; body mass index; cross-sectional survey; obesity; school children; waist circumference