'Thinfat' phenotype in newborns.

OBJECTIVE: The objectives of the study was to know whether the 'thinfat' phenotype exists in newborns, in Central Karnataka and to correlate various factors that contribute to this peculiar phenotype, with emphasis on genetic and maternal environmental factors. METHODS: For 1000 consecutive singleton term newborns, weight, length, head, mid arm, abdominal circumferences, biceps and subscapular skinfolds were measured at birth and compared with measurements of white Caucasian babies born in Southampton UK and Mysore babies at birth. RESULTS: The Davangere babies were significantly smaller in all measurements at birth (p < 0.001) compared to Southampton babies. The deficit varied according to the measurements; It was greatest for birth weight (-1.6 SD, CI -3.0, -0.2), mid arm circumference (-2.0 SD, CI -3.3, -0.8), head circumference (-1.8 SD, CI -3.1, -0.5) and least for length (-0.4 SD, CI -1.9, 1.1) and subscapular skin fold (-0.3 SD, CI -0.25, -0.12). Predictors of skinfold thickness were maternal body mass index (p < 0.05), maternal mid arm circumference (p < 0.001) and consanguinity (p < 0.05). CONCLUSION: Despite being small, truncal adiposity was present in Davangere neonates confirming the 'thinfat' phenotype. The role of consanguinity in other words, the role of genes, is important in determining this 'thinfat' phenotype in newborns.