Cardiovascular disease risk factors in 5-year-old urban South African children - The birth to ten study

Background. A birth cohort study, the Birth to Ten (BTT) study, commenced in the greater Johannesburg/Soweto metropole in South Africa in 1990. The overall BTT project collected antenatal, birth and early development information on these children as well as information that could help identify factors related to the emergence of risk of cardiovascular diseases (CVDs) in children. Objective. To determine CVD risk profiles and their determinants in 5-year-old children living in an urban environment in South Africa. Methods. Demographic and birth characteristics were collected on a sample of 964 5-year-oids whose parents agreed for blood samples to be taken from their children. The children's height and weight were measured using standardised procedures; blood pressure (BP) was measured with a Dinamap Vital Signs Monitor, and a nonfasting blood sample was drawn for lipid determinations. Information on exposure to tobacco smoke and additional health-related data were obtained by interview. Results. No differences were found between the birth weight and gestational age of the 5-year-old CVD participants and the remainder of the children studied at birth. The systolic BP was significantly different between ethnic groups, with the BF of the black children significantly higher than that of the Indian and white children, while the diastolic BP of black children was also the highest. White children had the highest mean total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels, significantly higher than those in the black community. The coloured children's TC level was also significantly lower than that of the whites, while the LDLC level of the Indian children was significantly higher than that of the blacks. Overall, 64% of the children were exposed to environmental tobacco smoke (ETS), with the white group having the lowest rate (45% exposed to ETS). The coloured children were most frequently exposed to ETS, with 40.6% having primary caregivers who smoked; of these children 42% lived in homes with two or more smokers. Conclusions. Tobacco control legislation will protect South Africans against tobacco sales promotions. This will be the first step towards increasing the priority of chronic disease prevention, health promotion and appropriate care for chronic diseases and their risk factors on the South African health policy agenda. The groups of children that were studied carried differing but significant levels of CVD risk. This suggests that the promotion of a healthy lifestyle should start in childhood, and should target the risk factors found in each group.