No abstract

Leptin, the ob gene product, plays an important role in the regulation of body fat mass and weight. In previous studies, it was demonstrated that leptin is detectable in human fetal cord blood as early as at 18 weeks of gestation and that serum leptin concentrations are significantly reduced in small gestational age newborns. In the present study, we investigated whether umbilical and maternal serum leptin concentrations correlate with intrauterine growth retardation (IUGR). In addition, we aimed to determine the relationships between leptin concentration in the maternal and cord blood. We studied 40 newborn infants (21 female and 19 male; gestational age, 38-42 weeks) and their mothers. Of the infants studied, 10 had IUGR. Serum leptin concentrations were measured by radioimmunoassay. All newborns had detectable leptin concentrations. Leptin concentrations were significantly lower in newborns with IUGR and in their mothers (n = 10; 3.53 +/- 1.42 ng/ml, 6.75 +/- 1.47 ng/ml, respectively) than in infants experiencing normal growth and their mothers (n = 30; 5.58 +/- 2.98 ng/ml, 9.85 +/- 6.50 ng/ml, respectively) (p < 0.01 for newborns, p < 0.05 for mothers). There was no significant correlation between umbilical leptin concentration and maternal leptin concentration (r = 0.229; p = 0.155) in all study groups but, significantly, a correlation was observed in the group with IUGR (r = 0.736; p = 0.015). There were no significant correlations between both umbilical and maternal leptin concentrations and parity, delivery type and gestational age. There was a correlation between umbilical leptin concentration and birth weight of newborns (r = 0.383; p = 0.015) but no correlation with body mass index (BMI) of the newborns (r = 0.034; p = 0.834). Maternal leptin concentrations correlated with maternal weight and BMI (r=0.606; p=0.000, r=0.535; p=0.000, respectively). There was no correlation between maternal leptin concentrations and birth weight of the newborns (r=0.179; p=0.269) and with BMI of the newborns (r = 0.146; p = 0.367). There was no gender difference in leptin concentrations in the newborns (n=21; 5.50 +/- 3.37 ng/ml, for females; n = 19; 4.58 +/- 1.98 ng/ml for males) (p = 0.296). In summary, we have shown that IUGR is associated with a decreased leptin concentration in newborns and their mothers. The association between umbilical serum leptin and birth weight in this and other studies suggests a pivotal role of fetal leptin in regulating fetal growth and development.

The results of this study have suggested that change in the leptin content of breast milk during lactation might play a role in the regulation of weight gain in healthy neonates.

No abstract

Cigarette smoking has been implicated in the pathogenesis of ischemic heart disease, emphysema, obstructive lung disease and neoplastic disorders. More than 1000 constituents of smoke, including many oxidants, pro-oxidants, free radicals and reducing agents, have been identified. The activities of erythrocyte superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), which are the important components of antioxidant defense system, were measured in 100 healthy volunteers. This study included heavy smokers (consuming cigarettes > or = 20 per day; n=30, group I), light smokers (consuming cigarettes<20 per day; n=30, group II), passive smokers (exposed to cigarette smoke in the indoor environment; n=20, group III), and non-smokers (n=20, the control group). While activities of SOD and CAT in erythro cytes were significantly lower in groups I, II and III than in the control group (p<0.01 for all), mean erythrocyte GSH-Px activity in group III was higher than that in groups l, II and in controls. These results suggest that the increased oxidative stress occurs in smokers, owing to the free radicals present in smoke. It might cause a decrease in antioxidant enzyme activities and oxidant/antioxidant imbalance. We also observed that passive smokers were affected by the environmental smoke to the same extent as active smokers.