Obésité et facteurs de risque cardio-métabolique chez les adolescents scolarisés dans la wilaya de Jijel

Abstract

Juvenile obesity is a multifactorial progressive pathology, its prevalence is increasing at an alarming rate worldwide. However, their causes are obscure and poorly understood in Algeria. It is a cardiometabolic risk factor, especially if it is associated with metabolic syndrome. Thus, the aim of the present thesis is to estimate the prevalence of general and abdominal obesity in adolescents, to evaluate the cardiometabolic risk determinants related to this epidemic and to study the relationship between uric acid, leptin and insulin with the components of the metabolic syndrome. To attain this objective, an epidemiologicalbiochemical study was conducted between 2014 and 2015. For this, 577 adolescents attending school in the province of Jijel (north-eastern Algeria) aged from 11 to 19 years were recruited to answer the questionnaires and to take their anthropometric measurements and their blood pressure. After 8 to 12 hours of fasting, serum concentrations of glucose, lipids and uric acid were examined in 204 adolescents (23: severe obesity, 75: obesity, 17: overweight and 89: normal weight) and serum concentrations of insulin and leptin in 40 adolescents. The results confirm the heterogeneous nature of obesity, whether in its causes or in its cardio-metabolic consequences. The epidemiological study shows that the prevalence of excess weight (body-mass-index Z-scores ≥1; WHO 2007), general obesity (body-mass-index Z-scores ≥2; WHO 2007) and abdominal (ratio of waist circumference/height ≥0.50) are 18.37%, 5% and 12.13% respectively. The factors influencing excess weight among adolescents are: urban and plain residential area, high socioeconomic status, high birth weight, artificial breastfeeding, childhood weight gain, female sex, puberty, excess weight in family members, bad dietary habits, and physical inactivity. In addition, the biochemical study reveals that obese adolescents are more exposed to abdominal obesity, hypertension, hyperuricemia, hyperleptinemia, hyperinsulinemia and glycolipid abnormalities compared to normoponderals (p ˂ 0.001). According to the International Diabetes Federation (2007), the frequency of metabolic syndrome is 17.4% among excess weight adolescents, while it is not observed among normal weight adolescents (p ˂ 0.001). The high uric acid level is associated with the metabolic syndrome criteria, except for hyperglycemia. The uric acid, leptin and insulin levels are significantly higher in adolescents with metabolic syndrome compared to those without metabolic syndrome. The uric acid level is correlated with leptin level (in girls) and insulin level (in boys), however the molecular explanation of these associations is poorly known to date. The high waist/height ratio, hyperleptinemia, hyperinsulinemia and hyperuricemia are markers of the metabolic syndrome. In conclusion, juvenile obesity is a dominant current issue, its management is a primary objective, given the growth of this pathology and its consequences that it generates on health. The coexistence of obesity and metabolic syndrome are major factors of cardiometabolic risk, hence the early diagnosis of metabolic syndrome in obese adolescents is necessary and