LEPTIN LEVELS DISTRIBUTION AND ETHNIC-BACKGROUND IN 2 POPULATIONS FROM CHILE - CAUCASIAN AND MAPUCHE GROUPS

OBJECTIVE: Leptin, the product of the human ob gene is increased in ob ese individuals, suggesting resistance to its effect. We examined the relationship of serum leptin levels with respect to obesity, gender an d insulin levels in two populations with different ethnic compositions in Chile. METHODS: Leptin and insulin levels were determined by radio immunoassay (RIA) and correlated with body mass index (BMI), gender an d ethnic background. 79 Caucasian subjects from Santiago and 65 Mapuch e natives from the Araucania region, Chile, were included in this stud y. RESULTS: Leptin concentrations in obese subjects were significantly increased in both ethnic groups in relation to lean status: Caucasian and Mapuche obese 19.3+/-11.6 and 10.1+/-5.8 (P<0.001), respectively vs Caucasian and Mapuche lean 10.4+/- 5.8 and 4.7 +/- 2.9 (P < 0.001, respectively). When we compared Mapuche and Caucasian groups, similar leptin levels were observed among the males of the two populations in both metabolic states (lean and obese). In contrast, the leptin level distributions between women showed a marked difference, having a minor value in the Mapuche women with a comparable value with the male grou p in this ethnic population. CONCLUSIONS: The leptin concentrations ar e associated with obesity in both ethnic groups in Chile. However, the leptin levels between the Mapuche natives were significantly decrease d compared to the Caucasian group. The gender distribution does not se em to be important in the Mapuche natives. The ethnic composition seem s to be important in the leptin distribution in the analysed populatio ns.