Development and tracking of body mass index from preschool age into adolescence in rural South African children: Ellisras Longitudinal Growth and Health Study.

The purpose of this observational prospective cohort study was to investigate the development and tracking of body mass index (BMI) of Ellisras rural children from preschool age into late adolescence from the Ellisras Longitudinal Growth and Health Study. Heights and weights of children were measured according to the standard procedures recommended by the International Society for the Advancement of Kinanthropometry twice a year from 1996 to 2003. In total, 2,225 children--550 preschool and 1,675 primary school--aged 3-10 years (birth cohorts 1993 to 1986) were enrolled at baseline in 1996 and followed through out the eight-year periodic surveys. In 2003, 1,771 children--489 preschool and 1,282 primary school--were still in the study. The prevalence of overweight was significantly higher among girls (range 1.6-15.5%) compared to boys (range 0.3-4.9%) from age 9.1 years to 14.9 years. The prevalence of thinness (severe, moderate, and mild) ranged from 7.1% to 53.7% for preschool children and from 8.0% to 47.6% for primary school children. Both preschool and primary school children showed a significant association between the first measurements of BMI and the subsequent measurement which ranged from B=0.2 (95% confidence interval [CI] 0.1-0.4) to B=0.8 (95% CI 0.6-0.9) for preschool and B=0.2 (95% CI 0.1-0.3) to B=0.7 (95% CI 0.6-0.8) for primary children. A significant tracking of BMI during 4-12 years of life was more consistent for preschool children (B=0.6 (95% CI 0.6-0.7) and for primary school children (B=0.6 (95% CI 0.5-0.6). Investigation of nutritional intake and physical activity patterns will shed light on how healthy these children are and their lifestyle.

Relationship between fat patterns, physical fitness and blood pressure of rural South African children: Ellisras Longitudinal Growth and Health Study.

The present study investigated the relationship between blood pressure (BP), fat patterns and fitness parameters of Ellisras children aged 7-13 years. Furthermore, an assessment of body fat patterns was done to determine the subjects with the highest risk of overweight, hypertension and waist-to-hip ratio above the 90th percentile. Data were collected from 1,817 subjects (938 boys and 879 girls), aged 7-13 years, participating in the Ellisras Longitudinal Study. Anthropometric measurements were taken according to the standard procedure of the International Society for the Advancement of Kinanthropometry. The EUROFIT test items were used to test the physical fitness of 1,192 subjects (634 boys and 558 girls). Obesity was defined using the international recommended cutoff points for body mass index (BMI) in children. Hypertension was defined as the occurrence of BP levels greater or equal to the 95th percentile of height- and sex-adjusted reference levels. The prevalence of hypertension ranged from 1 to 11.4% and that of overweight 0.6-4.6%. Waist girth, BMI, triceps and subscapular skinfold showed significant (P<0.001-0.05) correlation with other fat pattern parameters (r ranging from -0.157 to 0.978) compared with significant correlations (P<0.001-0.05) with BP (r ranging from -0.071 to 0.164). Children with waist girth greater than the 90th percentile are more likely to have multiple risk factors than the children with a waist girth that is less than or equal to the 90th percentile. Longitudinal studies should verify whether changes in waist girth and skinfolds will indicate changes in cardiovascular risk factors during growth.

Somatotype and blood pressure of rural South African children aged 6-13 years: Ellisras longitudinal growth and health study.

BACKGROUND: Physique has been useful in assessing the outcome of underlying growth and maturity processes, which leads to a better understanding of variation in child and adult health. However, a high endomorphy rating has been associated with hypertension in adults, posing a serious threat to their health status, while receiving little attention in children. AIM: The study examined the association between somatotypes, body mass index (BMI) and blood pressure (BP) in 6-13-year-old rural children, in Ellisras, South Africa. SUBJECTS: A total of 1902 subjects (980 boys and 922 girls) aged 6-13 years were studied as part of the Ellisras Longitudinal Study. Height, weight, four skinfold sites, two breadths, and two girths were measured according to the International Society for the Advancement of Kinanthropometry (ISAK). The Heath-Carter method of somatotyping was used, together with internationally recommended cut-off points for BMI in children. Hypertension, defined as the average of three separate BP readings, where the systolic or diastolic BP is greater than or equal to the 95th percentile for age and sex, was determined. RESULTS: The prevalence of hypertension ranges from 1 to 5.8% in boys and 3.4-11.4% in girls. The prevalence of overweight ranges from 1.1 to 2.9% in boys and 0.6-4.6% in girls. Systolic BP and BMI showed a significant positive correlation at age 6 years (r = 0.436) and 10-13 years (r = 0.180-0.246 in boys and r = 0.221-0.271 in girls). Diastolic BP showed an insignificant correlation with the BMI and somatotype components in boys and girls. CONCLUSION: A significant association exists between BP and BMI, and ectomorphy components even after being adjusted for age, gender and height. The need to manage hypertensive individuals is evident in this sample to combat this chronic disease from an early age. Follow-up studies should investigate the relationship between BP and the dietary intake of these children.

The association of fat patterning with blood pressure in rural South African children: the Ellisras Longitudinal Growth and Health Study.

BACKGROUND: Hypertension is one of the major causes of death in developed and underdeveloped nations. Essential hypertension and obesity may have their inception in childhood, with little data in African children to support these findings. Objectives were to determine the prevalence of overweight and hypertension in rural children in South Africa. Additionally, the association between fat-patterning ratios and blood pressure (BP) was investigated. METHODS: Data were collected from 1884 subjects (967 boys and 917 girls), aged 6-13 years, participating in the Ellisras Longitudinal Study. Height; weight; and triceps, biceps, subscapular, and suprailiac skinfolds were measured according to the protocol of the International Society for the Advancement of Kinanthropometry. Skinfold ratio was used as an indicator of the central pattern of body fat. Internationally recommended cut-off points for body mass index (BMI) were used. Hypertension, defined as the average of three separate BP readings where the systolic BP or diastolic BP is >or=95th percentile for age and sex, was determined. RESULTS: The prevalence of hypertension ranged from 1 to 5.8% for boys and 3.1 to 11.4% for girls, and that of overweight from 1.1 to 2.9% for boys and 0.6 to 4.6% for girls. The association between high systolic BP and high BMI was -3.0, while that for high diastolic BP and high BMI was -0.68. CONCLUSIONS: The prevalence of hypertension is evident from the age 6 years for girls, while that of overweight was low. Overweight became evident from the age 10 to 13 years for both sexes. A significant association between high diastolic BP and high BMI was noted, while children with low BMIs were less likely to be hypertensive. Investigating habitual physical activity, fitness and dietary patterns will shed more light on the association of fat patterning and BP in this population.