Low birth weight and insulin resistance in mid and late childhood

Low birth weight is associated with adult insulin resistance and diabetes. We conducted this study to correlate low birth weight with insulin resistance in mid and late childhood.

Children whose birth weight records were available were successively enrolled from middle and low socioeconomic status urban schools in western India. 600 children in age groups 5-16 years were screened for availability of recorded birth weight in six schools. Detailed birth records were available for 158 children born full term. Parents of 134 (84.8%) agreed to participate in the study after informed consent. These children were evaluated for various anthropometric indices and fasting blood was obtained for determination of glucose and insulin levels. Insulin resistance was determined using homeostasis model assessment (HOMA) and HOMA-2 formula. Comparative, univariate and multivariate statistical analyses were performed.

The mean age of the children was 10.0 +/- 2.4 years. Maternal diabetes was present in 3 (2.2%). Mean weight at birth was 2.84 +/- 0.61 kg and low birth weight (<2.5 kg) was in 49 children (36.6%). There was no significant statistical difference in current height, weight, body mass index, waist, hip, waist hip ratio, mid upper arm circumference, and systolic and diastolic blood pressure in children born with low or normal birth weight (P >0.10). In low birth weight as compared to normal birthweight children mean fasting blood glucose (80.1 +/- 16.1 vs. 70.1 +/- 14.8 mg/dL; P = 0.042), median (interquartile range) fasting insulin levels (10. 18, 6.08-18.54 vs. 2.12, 0.02-7.45 microU/mL; Mann Whitney U test, p<0.0001), and HOMA-derived insulin resistance (1.88, 1.06-4.52, vs. 0.35, 0.02-1.52, P < 0.0001) were significantly greater. There was a significant negative correlation of birth weight with fasting insulin levels after multifactorial adjustments (partial correlation coefficient r = -0.436, P <0.001). Multivariate conditional logistic regression analysis revealed that birthweight was significant determinant of fasting insulin levels after adjusting for age, gender, body mass index, waist and waist hip ratio (odds ratio 3.82, 95% confidence intervals 1.16-12.63, P = 0.028).

Children born with low birth weight have significantly greater fasting glucose, fasting insulin levels and insulin resistance at mid and late childhood.