Seasonal variation in blood pressure and visceral fat indices among Lephalale rural children: Ellisras Longitudinal Study (ELS)

Abstract

Hypertension and obesity have been a growing concern globally. Their prevalence continues to escalate, affecting a lot of people, especially in cold seasons. This leads to high mortality in cold seasons due to the increased prevalence of non-communicable diseases. This study investigated seasonal variation in blood pressure and visceral fat indices among the Ellisras (now known as Lephalale) population. The longitudinal study took place in Ellisras, Limpopo Province of South Africa. A total of 1 974 (1033 boys and 941 girls) participants aged 4−18 years enrolled in this study. The protocol of the International Society for the Advancement of Kinanthropometry (ISAK) was followed for all anthropometric measurements. Blood pressure was taken following the procedure of the National High Blood Pressure Education Program’s (NHBPEP) Working Group on Hypertension Control in Children and Adolescents. Obesity and hypertension prevalence was determined using frequency analysis. Cases of elevated systolic blood pressure (BP) weresignificantly higher in spring (6.6%) than in autumn (3.1%) among boys aged 4−7 years in 1999. Hypertension was substantially (p<0.01) more prevalent in spring (12.8%) than autumn (0.8%) among girls aged 4−7 years in 1999. Among boys aged 8−11 years in 2001, obesity (estimated by waist circumference), was markedly (p<0.01) higher in autumn (8.9%) than spring (1.3%). Obesity measured by waist-to-hip ratio, was significantly (p<0.01) more preponderant in autumn (95.5%) than spring (84.2%) among girls aged 8−11 in 1999. Age-related seasonal variation in blood pressure and visceral fat indices was evident in Lephalale rural population of boys and girls.