DOES LEPTIN LEVELS AFFECT CARDIOMETABOLIC FACTORS INDEPENDENTLY OF ADIPOSITY IN OBESE BRAZILIAN CHILDREN? Maria Edna Melo 1,2,3, Clarissa TH Fujiwara 1, Heidi Lui Reinhardt 1,2,3, Alfredo Halpern 3, Marcio C Mancini 1,2,3 1 Liga de Obesidade Infantil, 2 Laboratório de Carboidratos e Radioimunoensaio/LIM 18, 3 Group of Obesity and Metabolic Syndrome, Hospital das Clinicas, Faculty of Medicine, University of Sao Paulo; Sao Paulo, Brazil BACKGROUND: Increased body mass index (BMI) and waist circumference (WC) are related to cardiometabolic risk (CMR) factors. Studies assessing if leptin independently affects CMR factors are controversial. Some studies assert that leptin is not an independent factor of adiposity affecting CMR and others affirm that it predicts a worsening of the CMR features independently of obesity. It is well known that leptin is synthesized in white adipose tissue, and correlates with its level. Therefore, because BMI is not a precise measure of fat mass (FM), it is possible that even after adjusting the associations between leptin and CMR factors for BMI, residual confounding by adiposity could persist. CONCLUSION: In conclusion, though some studies assert that leptin is an independent factor adversely affecting CMR factors, our study suggests that leptin adjusted for FM does not have a regulatory role for CMR in obese Brazilian children and adolescents. METHODS: Seventy-five subjects (42 girls and 33 boys) aged 12.2  2.6 years ( ) were submitted to anthropometric (BMI z-score, WC), body composition (FM and fat-free mass [FFM] percentage assessed by bioelectrical impedance analyzer) and CMR profile (fasting insulin and glucose levels, 120-minute insulin and glucose response to an oral glucose tolerance test [OGTT], HOMA-IR, blood pressure [BP] and lipid profile). Pearson correlation was used to determine associations between continuous variables. REFERENCES 1. Feitosa ACR et. Al. Relação entre o perfil metabólico e níveis de leptina em indivíduos obesos. Arq Bras Endocrinol Metab (1): Liuzzi A et al., Serum leptin concentration in moderate and severe obesity: relationship with clinical, anthropometric and metabolic factors Int J Obes Relat Metab Disord. 1999; 23(10): García-Lorda Pet al. Leptin concentrations do not correlate with fat mass nor with metabolic risk factors in morbidly obese females. Diabetes Nutr Metab. 2001;14(6): Huang KCet al. Plasma leptin is associated with insulin resistance independent of age, body mass index, fat mass, lipids, and pubertal development in nondiabetic adolescents. Int J Obes Relat Metab Disord. 200;28(4): OBJECTIVES: To evaluate the relationship between leptin levels and leptin levels adjusted for FM and anthropometric, body composition and CMR profile in a cohort of obese Brazilian children and adolescents. RESULTS: RESULTS: Clinical and metabolic features are on Tables 1 and 2. Leptin levels were positively related to WC measurement at the midpoint (WC-MP) between lowest rib and iliac crest and to WC at the iliac crest (WC-IC), and negatively related to FFM percentage (Fig. 1 and Tab. 3). Leptin levels were also related to insulin levels, HOMA-IR, 120-minute glucose response and 120-minute insulin response to an OGTT (Fig. 1 and Tab. 3). All correlations were lost when the analysis was performed with leptin levels adjusted for FM (Tab. 30., Average ± SD Weight (kg)79.1 ± 21.0 Height (percentil)86.5 ± 44.4 BMI (kg/m 2 )32.6 ± 5.7 Z-IMC2.3 ± 0.3 WC – MP (cm)100.7 ± 13.4 WC – IC (cm)104.1 ± 13.6 SBP (percentil)71.6 ± 22.8 DBP (percentil)75.2 ± Fat mass (%)37.9 ± 4.5 Free-fat mass (%)61.9 ± 4.6 Average ± SD Glucose (mg/dl)85.1 ± 12.0 Insulin (mUI/ml)18.2 ± 15.3 Glucose T120’114.7 ± 20.8 Insulin T120’92.7 ± 55.7 HOMA-IR(0.6 – 28.0) Cholesterol (mg/dl)157.2 ± 28.5 HDL Cholesterol44.6 ± 7.9 LDL Cholesterol92.4 ± 25.8 Triglycerides (mg/dl)101.4 ± 48.5 Leptin (ng/ml)34.9 ± 23.4 Leptin/FM (kg)1.2 ± 0.7 Insulin (mUI/ml) Leptin (ng/ml) HOMA-IR Leptin (ng/ml) 120-min Glucose (mg/dl) 120-min Insulin (mUI/ml) LeptinLeptin/FM rprp WC-MP WC-IC SBPp DBPp FM (%) FFM (%) Glucose 0’ Insulin 0’ Glucose 120’0.689< Insulin 120’0.599< HOMA-IR Cholesterol HDLc LDLc Triglycerides Supported by: FAPESP 2008/ PO2-268 Table 1. Clinical Features of the patients Table 2. Metabolic Features of the Patients Waist circumference - midpoint (cm) Free-fat mass (%) Leptin (ng/ml) Waist circumference - iliac crest (cm) Figure 1. Positive correlations between leptin and clinical and metabolic parameters. Table 3. Positive correlations with leptin and lost after adjustment to fat mass. Financial Disclosure Statement: authors have no financial relationship to disclose within the past 12 months relevant to this presentation. r=0.358 p=0.017 r=0.323 p=0.030 r= p=0.036 r=0.439 p=0.002 r=0.409 p=0.005 r=0.689 P<0.001 r=0.599 P<0.001