Objective: To assess the metabolic characteristics, body composition, Insulin resistance and energy expenditure in young South Indian males with low and normal birth weight.
Methodology: A population based cohort of 43 low birth weight (<2.5 kg) and 41 normal birth weight (>2.5 kg) subjects born at term was taken from a rural part in the South Indian state of Tamilnadu. Young healthy males aged 18–22 years were recruited. Following informed consent anthropometric data and hyperinsulinemic euglycemic clamp were performed and the M value was calculated. Resting energy expenditure was measured by indirect calorimetry.
DEXA was used for measuring total/regional body composition. Actiheart was used to measure total energy expenditure (TEE).
Results: Data from 84 subjects was analyzed. Anthropometric and clinical characterizations were as follows; BMI: 19.1 (±2.97) kg/m2, waist circumference: 69.8 (±7.92) cm, serum triglycerides: 0.91 (±0.58) mmol/l and HDL: 0.82 (±0.22) mmol/l). There was no significant difference between the normal and low birth weight subjects.
Birth weight was negatively correlating with fat content (r=−0.232; P=0.036), but was significantly correlating with REE (r=0.235; P=0.032) and TEE (r=0.280; P=0.017).
The glucose infusion rate during insulin stimulation (M value) was 11.3 (±3.88) mg/min per kilogram FFM. Correlations between the ‘M’-value and insulin resistance indices is as follows: QUICKI (r=0.344; P=0.001), HOMA (r=−0.351; P=0.016) and Mc Auleys (r=0.389; P=0.007).
Summary: This is the first study where body composition and insulin resistance were simultaneously studied in low/normal birth weight young males. There is a trend showing that low birth weight subjects have more fat content, increased triglycerides and increased insulin resistance. REE and TEE were significantly correlating with birth weight. The lesser the birth weight the less energy expenditure.