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The aim of the present study was to determine in adolescents the relationship between insulin levels and body mass index (BMI), body fat distribution, diet, life style and lipid profile. We studied 167 adolescents (68 boys and 99 girls) whose ages ranged from 14 to 17 years. A detailed medical (including pubertal stage) and nutritional record was obtained from each subject. Biochemical measurements included fasting serum insulin, glucose, total cholesterol (TC), triglycerides (Tg), HDL-C, LDL-C and VLDL-C. HOMA insulin resistance (IR) and HOMA beta-cell function (beta-cell) were calculated. Insulin levels were over 84 pmol/L (cut off normal value in our lab) in 56% of the boys and 43% of the girls. Thirty-seven percent of lean adolescents whose BMI was 21.5 +/- 1.9 kg/m2 presented higher fasting insulin levels. HOMA IR, Tg, systolic (SBP) and diastolic blood pressure (DBP) values when compared to a lean normoinsulinemic group. Insulin levels were correlated (p < 0.01) with body mass index. Both boys and girls in the highest BMI quartile (BMI > 24 kg/m2) had significantly higher serum insulin, HOMA beta-cell, and Tg levels, and the lowest HDL-C levels. A high-energy intake rich in saturated fat and low physical activity were found in this lean but metabolically altered adolescents. We conclude that even with a BMI as low as 21 kg/m2 an inappropriate diet and low physical activity might be responsible for the high insulin levels and dislipidemias in adolescents.

To analyze the nutritional and metabolic risk factors for Cardiovascular Diseases (CVD) present in a group of people in the city of Maracaibo a study was performed with 209 volunteers (145 women and 64 men) between 20 and 89 years of age who underwent: a) Anthropometric Evaluation: Body Mass Index (BMI) and Waist-to-Hip Ratio (WHR) and Physical Examination: Systolic (SBP) and Diastolic Blood Pressure (DBP); b) Dietetic Evaluation (24 hours recall), and c) Biochemical Evaluation: Glycemia (GLYC), Triglycerides (TG), Total Cholesterol (CHOL), HDL-C, LDL-C and VLDL-C, applying enzymatic methods. It was also investigated, their Age, Family History of Metabolic Alterations (FHMA), physical activity, smoking habits and alcohol consumption. More than 50% of the individuals showed a BMI > 25; 64% of women showed a WHR value > 0.8; 34 and 28% of men and women respectively had a high fat ingestion (HFI); 36% of men had hypertriglyceridemia and high levels of VLDL-C; 41% of women and 30% of men showed decreased HDL-C. A high frequency of FHMA was found in 85% of women and 78% of men followed by sedentary life in 64% of men and 79% of women. The age significantly (p < 0.05) affected the values for WHR, SBP, DBP, GLYC, CHOL, TG, HDL-C, LDL-C and VLDL-C. The dietetic evaluation showed a diet that was low in calories, high in protein, normal in fat and low in carbohydrates. It is concluded that the population elected for this study might be considered under a high risk for CVD, since both nutritional and metabolic factors, as well as the other risk factors analyzed, were present in a high percentage of the individuals studied.

With the purpose of exploring the glucose and insulin responses to a breakfast composed of a complex carbohydrate (CC) in the form of a "arepa" prepared with precooked corn flour, with or without the addition of protein and fat (CC + P + F), we studied 6 healthy volunteers, ages ranging from 26-50 years and body mass index of 24.5 +/- 1.32. Three tests were performed on each individual: 1) 75 g OGTT, 2) Ingestion of 75 g of CC ("arepa") and 3) Ingestion of 75 g of CC + 6.7 g protein (low fat cheese) and 4 g fat (margarine). Glycemic values (glucose - oxidase method) and insulinemia (radioimmunoassay) were determined at basal, 30, 60, 120, 180 and 240 min. Glucose (GA) and insulin (IA) areas, glycemic index (GI) and insulin/glucose ratio (I/G) were calculated. We found that the "arepa" has a high GI (71.5%) that it is increased, although not significatively to 140% with the addition of protein and fat. Total GA as well as IA obtained for CC and for CC + P + F were similar to OGTT, however the profiles of the glucose and insulin responses during CC and CC + P + F were less abrupt but more prolonged, resulting in a greater I/G ratio for OGTT in comparison with CC or CC + P + F during the initial steps. We conclude that GI of this corn bread ("arepa") is high in comparison to other complex carbohydrates and it is not altered by the addition of protein and fat. This is possibly due to glucose and insulin responses similar to that produced by OGTT.