SAN DIEGO – Adiponectin, a “healthy” hormone secreted from adipose tissue, was higher in adolescent females compared with males, and decreased as body weight increased, a longitudinal cohort analysis demonstrated.

“Low adiponectin levels are associated with metabolic risk, regardless of fat mass and sex,” lead study author Dr. Marcela Reyes said at the annual meeting of the Pediatric Academic Societies. “There is currently a gap in knowledge in factors that determine circulating adiponectin levels.”

In an effort to evaluate the role of infancy exposures (duration of breast feeding and weight-gain velocity) on adolescent adiponectin levels after taking into account gender and fat mass, Dr. Reyes and her associates studied a cohort of 584 normal–birth weight adolescents who were recruited at age 4 months for an iron deficiency preventive trial in Santiago, Chile from 1991 to 1996 and evaluated for cardiovascular risk 16 years later.

Dr. Reyes of the Institute of Nutrition and Food Technology at the University of Chile, Santiago, and her associates prospectively assessed breastfeeding from the age of 4 months and measured weight and height monthly. Adolescent outcomes included body mass index (BMI) z-scores, fat mass, and fasting serum adiponectin levels. The researchers used linear regression to model the effect of short breastfeeding (defined as breastfeeding for shorter than 180 days as the sole source of milk, as recommended by pediatricians) and weight gain in the first 6 months on adolescent adiponectin levels, after controlling for fat mass and gender.

The mean body weight at birth of the 584 adolescents was 3.5 kg, which increased to 8.0 kg at 6 months, with no change in the weight-for-age z-scores; 75% experienced a short exposure to breastfeeding. At age 16 years, their mean adiponectin level was 11.3 mcg/mL and differed by weight status and gender.

Specifically, the mean adiponectin levels among normal weight, overweight, and obese males were 11.06, 8.86, and 7.80 mcg/mL, respectively, while the mean adiponectin levels among normal weight, overweight, and obese females were 13.42, 12.12, and 9.04 mcg/mL, respectively. After the researchers controlled for gender and fat mass in adolescence, they found that shorter breastfeeding and change in weight-for-age z-score were associated with lower adolescent adiponectin levels (a 1.5 mcg/mL decrease in adiponectin levels for shorter breast feeding and a 0.7 mcg/mL decrease for every unit increase of weight-for-age z-score).

“Adiponectin levels are heterogeneous across sex and weight status,” Dr. Reyes concluded. “Earlier first bottle and higher weight gain during the first 6 months of age were associated with lower adiponectin levels in the adolescents.” She characterized the first 1,000 days of life as “a window of opportunity to try to prolong breastfeeding or to deal with rapid weight gain. This could help adolescents have healthier metabolic performance that may carry over into later life.”

The study was funded by the National Institutes of Health. Dr. Reyes reported having no relevant financial disclosures.

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