Cardiovascular Risk Factors and their Relationship with Endothelial Dysfunction in Rural and Urban South African Children

Abstract

Background: Endothelial dysfunction is known to be an initiator to the development and progression of atherosclerotic cardiovascular disease (CVD). However, there is paucity o knowledge on its relationship with cardiovascular risk factors in children. More so, some of these cardiovascular risk factors are known to be influenced by feeding habits and life style changes which often vary between rural and urban settings. This study was aimed to investigate the relationship between cardiovascular risk factors and endothelial function in rural and urban children. Methods: A cross-sectional study on 6-9 years old children in randomly selected rural and urban schools of the Eastern Cape Province of South Arica was conducted. General anthropometric indices were measured followed by blood pressure (BP) measurements. The pulse wave velocity (PWV) was measured using a Vicorder. Urine sample was collected for the determination of albumin, creatinine, asymmetric dimethylarginine (ADMA), 8-hydroxy-2deoxyguanosine (8-OHdG) and thiobarbituric acid reactive substance (TBARS). Albumin to creatinine ratio (ACR) was calculated.Results: Children from urban settings (10.8%) had a higher prevalence of overweight/obesity than their rural counterparts (8.5%) while the prevalence of elevated/high blood pressure was higher in rural children (23.2%) than in urban children (19.0%). Diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) significantly (p<0.005) increased with increasing quartiles of PWV. ADMA positively associated with HR in rural girls and showed a weak risk for elevated SBP and MAP. Body mass index (BMI) increased with increasing PWV and predicted endothelial dysfunction. 8-OHdG significantly (p<0.005) increased with increasing quartiles of ADMA and positively correlated with ADMA. Creatinine, albumin and ACR significantly (p<0.005) increased with increasing ADMA and ADMA associated positively with creatinine. Conclusion: Endothelial dysfunction was associated with obesity, high blood pressure, oxidative stress and microalbuminuria in children, and this relationship varied between rural and urban children.