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Relation between dietary calcium intake with obesity and metabolic alterations in post-pubertal adolescents.

by dos Santos, Luana Caroline

Abstract (Summary)
Introduction: Several nutritional risk factors are related to obesity. Recently, some studies had demonstrated that dietary calcium intake as a negative contributor to adiposity. Clinical and experimental studies demonstrated that a possible mechanism is an increasing intracellular calcium concentration, which in turn act to promote lipogenesis, reduce lipolysis and hyperinsulinemia. Considering the shortage of similar data in adolescents, the present study evaluated the relation between dietary calcium intake with obesity in this population. Methods: Case-control and cross-sectional study, with normal weight (NW) and obese adolescents (OB). Anthropometric (weight and height) and body composition assessment (DXA) was analyzed. Biochemical analysis, included lipid profile, fasting glucose and insulin, as well as leptin and ghrelin. Dietary intake was assessed by a 3-day dietary record. Insulin resistance was calculated by HOMA-IR. Student?s t-tests, Pearson?s correlations, Chi-square or Fisher exact test, ANOVA and Odds-ratio were used to statistical analysis. The dietary calcium intake was adjusted by energy intake with residual nutrient method. Results: 96 post-pubertal adolescents, mean age 16.6(1.3)y were evaluated. Adolescents were divided in two groups paired by age and gender, 47 NW and 49 OB. Mean energy and macronutrients intake were similar between groups. Adjusted calcium intake was statistically higher in NW (692.1±199.5mg vs 585.2±249.9 in GO; p=0.02). A significant lower body fat mass, trunk and periferic fat mass were observed in the highest calcium intake quartile. Furthermore, glucose and insulin concentrations presented a statiscally significant difference between the lowest and highest calcium quartile. Analysis within study groups, showed an inverse association between adjusted calcium with trunk fat (r=-0.287, p=0.04), insulin concentration (r=-0.360, p=0.01), HOMA-IR levels (r=-0.365, p=0.01) and leptin (r=-0.345, p=0.02) in obese group. There was no relation between calcium intake with anthropometry and body composition or biochemical parameters in normal weight. Adolescents girls on highest quartile of calcium intake had significant reduction of obesity chance compared to lowest quartile (OR=0.13; IC95%=0.02-0.78; p=0.01). However, no adiposity protection by calcium intake was observed in boys. Conclusions: The results demonstrated that calcium intake was one factor related to obesity and insulin resistance in post-pubertal adolescents, and calcium intake seems to be a protective factor for obesity in girls, and encourage the recommendation for increase calcium intake in this life stage.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Ligia Araujo Martini; Nágila Raquel Teixeira Damasceno; Ligia Araujo Martini; Isa de Pádua Cintra Sampaio

School:Universidade de São Paulo

School Location:Brazil

Source Type:Master's Thesis

Keywords: calcium intake insulin resistance Obesity

ISBN:

Date of Publication:01/13/2006

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