The importance of the adiponectin and leptin relationship in in utero and infant growth

Abstract

Adiponectin is an adipocyte-derived, insulin-sensitizing, and anti-inflammatory cytokine that circulates in concentrations a thousand-fold greater than those of leptin or insulin. Leptin is a fat cell derived, 16 kDa protein that acts centrally to signal long-term energy stores to the brain and induces satiety by stimulating anorexigenic and inhibiting orexigenic neuropeptides. Adiponectin is measurable in cord serum by the 24th week of gestation, and concentrations rise 20-fold to term. Cord blood adiponectin values are significantly higher than those found in children and adults, in whom concentrations are inversely related to fat mass and body mass index, and, in contrast, correlate positively to birth weight, body mass index, and weight to length ratio. Umbilical cord leptin correlates positively with birth weight across the spectrum of fetal growth patterns. While placenta can secrete adiponectin, most of the adipokine appears to originate from fetal brown adipose tissue that forms by 14 weeks gestation. High molecular weight adiponectin, the presumed active isoform, correlates with leptin concentrations in cord blood. Lower leptin values in cord blood from small for gestational age babies may play a role in programming catch-up growth during infancy, while low levels of adiponectin in small for gestational age infants may contribute to childhood obesity and insulin resistance. The ratio of total adiponectin to leptin has been shown to correlate positively with weight gain from birth to mid-infancy.