Twins in Guinea-Bissau have a 'thin-fat' body composition compared to singletons

Undernourished Indian babies are paradoxically more adipose compared to European babies. In utero, twins are in a growth restricted environment and share nutritional sources, therefore, they might have a 'thin-fat' body composition compared to singletons. We compared anthropometry of twins (n=209, 97 males) and singletons (n=182, 86 males), using linear mixed-effect models in the Guinea-Bissau Twin Registry at the Bandim Health Project. Twins had lower birth weight (2420 vs 3100 g, p<0.001); and at follow-up, lower height (HAZ mean Z-score difference, -0.21, p=0.055), weight (WAZ -0.73, p=0.024) and BMI (BAZ -0.22, p=0.079) compared to singletons but higher adiposity (skinfolds: 0.33, p=0.001). Twins also had higher fasting (0.38, p<0.001) and 2-hr OGTT glucose concentrations (0.29, p<0.05). Data on prematurity was not available in this cohort. The thin-fat phenotype of Guinea-Bissau twins could suggest that it is a manifestation of early life undernutrition and is not exclusive to Indians. Keywords: Twins, adiposity, thin-fat, early life undernutrition, Guinea-Bissau.