Towards a simple marker of hepato-visceral adiposity and insulin resistance: The Z-score change from weight-at-birth to BMI-in-childhood.
Insulin resistance and hepato-visceral (central) fat excess are thought to contribute to an earlier timing of adrenarche/pubarche and puberty/menarche; this earlier timing in turn relates often to a mismatch between prenatal and postnatal weight gain, which can be estimated by calculating the Z-score change from birth weight (BW) to body mass index (BMI) in childhood. We tested the hypothesis that this calculation may serve as a proxy of insulin resistance and hepato-visceral adiposity in prepuberty by reappraising a cohort of children (mean age, 8.5 years), born appropriate- (AGA, n = 41) or small-for-gestational age (SGA, n = 45), followed since birth (n = 76) or since the age of 3 years (n = 10). Assessments included anthropometry; fasting glucose and insulin; liver volume; and hepatic fat, subcutaneous fat, and visceral fat in the abdominal region (by magnetic resonance imaging [MRI]). Z-score change BW-BMI closely associated to central fat (R = 0.74; P < .0001) and insulin resistance (R = 0.71; P < .0001). These results suggest that Z-score change BW-BMI could be viewed as a simple candidate-marker for hepato-visceral adiposity and insulin resistance in prepubertal children.