The leptin/adiponectin ratio in mid-infancy correlates with weight gain in healthy term infants, but is unrelated to serum insulin concentrations, body mass index, or skin fold thickness

Abstract

Aim: Rapid growth in infancy may be associated with later onset childhood obesity. The aim in this study was to evaluate the relationships of adipokines to growth of infants at 6-10 months of age and to serum insulin, glucose, and auxological parameters of infants and their mothers.

Methods: Thirty-seven healthy term AGA formula fed infants, 21 males, mean age 7.0 +/- 1.2 (SD) months, were evaluated during a nutritional assessment at a county health department. Length, weight, head circumference, waist circumference, mid-arm circumference, and subscapular skin fold and triceps skin fold thickness were determined. Mothers were weighed and their height measured, birth weight recorded from clinic records, and the infant's dietary history reviewed. Following finger stick for assessment of hemoglobin, a bedside blood glucose was determined and 250 microl of additional serum taken for assay of total adiponectin, high molecular weight (HMW) adiponectin (n=12), leptin, and insulin.

Results: The infants' total adiponectin to leptin ratio correlated significantly with the change in body weight from birth to mid-infancy (r = 0.349, p < 0.05). The mean total adiponectin was 34.2 - 16.6 microg/ml (n=37), mean HMW adiponectin 12.2 +/- 9.0 microg/ml (n=12), mean HMW/total adiponectin ratio 34.3 +/- 17.6%, and mean leptin 1.3 +/- 1.2 ng/ml. Neither total nor HMW adiponectin, leptin, nor the leptin/adiponectin ratio, correlated with serum insulin, glucose/insulin ratio, hemoglobin, birth weight, or auxological determinations of the infants or mothers.

Conclusions: As leptin and adiponectin are both insulin sensitizing hormones that change inversely with acquisition of body fat, and the leptin/adiponectin ratio correlates significantly with weight gain in mid-infancy, we postulate that this ratio might provide a marker relating to infantile growth and later adiposity.