Newborn size, infant and childhood growth, and body composition and cardiovascular disease risk factors at the age of 6 years: the Pune Maternal Nutrition Study

Abstract

Objective: To study associations of size and body proportions at birth, and growth during infancy and childhood, to body composition and cardiovascular disease (CVD) risk factors at the age of 6 years.

Design: The Pune Maternal Nutrition Study, a prospective population-based study of maternal nutrition and CVD risk in rural Indian children.

Methods: Body composition and CVD risk factors measured in 698 children at 6 years were related to body proportions and growth from birth.

Measurements: Anthropometry was performed every 6 months from birth. At 6 years, fat and lean mass (dual X-ray absorptiometry) and CVD risk factors (insulin resistance, blood pressure, glucose tolerance, plasma lipids) were measured.

Results: Compared with international references (NCHS, WHO) the children were short, light and thin (mean weight <-1.0 s.d. at all ages). Larger size and faster growth in all body measurements from birth to 6 years predicted higher lean and fat mass at 6 years. Weight and height predicted lean mass more strongly than fat mass, mid-upper arm circumference (MUAC) predicted them both approximately equally and skinfolds predicted only fat mass. Neither birthweight nor the 'thin-fat' newborn phenotype, was related to CVD risk factors. Smaller MUAC at 6 months predicted higher insulin resistance (P<0.001) but larger MUAC at 1 year predicted higher systolic blood pressure (P<0.001). After infancy, higher weight, height, MUAC and skinfolds, and faster growth of all these parameters were associated with increased CVD risk factors.

Conclusions: Slower muscle growth in infancy may increase insulin resistance but reduce blood pressure. After infancy larger size and faster growth of all body measurements are associated with a more adverse childhood CVD risk factor profile. These rural Indian children are growing below international 'norms' for body size and studies are required in other populations to determine the generalizability of the findings.

Figure 1. Pune Maternal Nutrition Study

Figure 2. Partial correlation coefficients (adjusted for age and sex) between size measurements from birth to 6 years and CVD risk factors measured at 6 years. (Those outside the shaded band are statistically significant, p<0.05)

Figure 3. Mean sex-specific within-cohort size SD scores from birth to 6 years for children above the top quartile for systolic blood pressure and HOMA-R at 6 years

Asterisks denote the statistical significance of the difference between SD scores of children above the top quartile for blood pressure or HOMA-R and the rest of the cohort; * p<0.05; ** p<0.01

Figure 4. Mean and 95% confidence intervals for SD change in fat and lean mass at 6 years per SD increase in size measurements (weight, height, MUAC, subscapular skinfold) at all ages from birth to 6 years

Figure 5. Mean and 95% confidence intervals for change in systolic BP and percentage change in HOMA-R at 6 years per SD increase in size measurements at all ages from birth to 6 years