Thèse de doctorat en Épidémiologie
Sous la direction de Serge Hercberg.
Soutenue en 2008
à CNAM .
Pas de résumé disponible.
Pas de résumé disponible.
The Coexistence of Stunting and Obesity in Infants and Young Children in the Eastern Mediterranean Region. Implications for National Nutritional Policies
Nutrition is an essential determinant of the physical, mental, social and spiritual well-being of the child. Malnutrition refers to states of deficiency, excesses or imbalance. The Body mass index (BMI) is only a proxy measure of body fatty mass. The application of a formula of BMI derived from a particular population produces a biased estimate when applied to other ethnic groups. A positive response of an obesity treatment program in children is accompanied by improvement of associated risk such as the metabolic syndrome and insulin resistance. The specific components of a program vary from a setting to another. In spite of its importance, there are few studies and no national or regional programs for obese children in the region of the Eastern-Mediterranean (EMME). Our objectives are to determine the nutritional status of underfives in certain countries in the region, to examine possible relation between common forms, to determine their risk factors, to examine the validity of the use of BMI in obese children including ethnics from EMME, and to estimate the effectiveness of management of obese children in a reference clinic in France. The data of 6 nationally representative surveys (PAPChild, PAPFAM, MICS) of more than 30000 children from 5 countries in EMME (Libya, Syria, Morocco, Djibouti, and Yemen) was used, as well as hospital data of 1114 obese children followed in a specialized clinic in France. Libya had a low prevalence of underweight, wasting, thinness and stunting, and high prevalence of overweight. In the population as a whole, W/H and BMI/A z-score curves were shifted to the right, while H/A z-score curve was shifted to the left. Other countries in the EMME also showed significant rates of stunting (18. 5 % in Libya - 57. 6 % in Yemen) and overweight (8. 9 % in the Yemen - 20. 2 % in Syria). Certain regions in these countries had higher rates of obesity (Halab and Al-Raka in Syria, 31. 5 and 47. 8 % respectively). The countries of EMME face a dual-burden. The risk factors for overweight in Libya include young age, living in the regions of Al-Akhdar or Alzaouia, boys, stunting and housing conditions. Breast feeding for more than six months decreases the risk of overweight. Risk factors for stunting in Libya include living in Al-Akhdar, boys, a low level of paternal education, poor psychosocial stimulation, drinking filtered water, poor garbage disposal, diarrhea and low birth weight. Older age of father and storing water in tanks were protective factors. The etiologic fraction of stunting in obesity at the population level in EMME extends from 7. 49 % to 69. 76 %. The etiologic fraction among those who have stunting is higher rural areas (80. 27 %) and in children older than four years (81. 24 %) in Libya. With the current modes of treatment for obesity in children, only 1/10 will return to normal weight, but a decrease in BMI/A z-score by 0. 5, which has a significant effect on the atherogenic profile and the insulin sensitivity, is possible in more than 2/5 of patients. Most of children seek treatment late (>5 years). Factors associated with poor and/or failure to respond to treatment include age <4 or >11 years at the beginning of management, prolonged duration of obesity, maternal obesity, previous participation in a management program, a high level of glycaemia and abdominal obesity. Stunting and overweight are public health problem in EMME. Risk factors for the higher rates in certain sub-regions need more studies. The results highlight the importance of combining efforts in national programs for overcoming under and overnutrition and the importance of civil engineering, early life factors as home conditions and complementary feeding practices. Interventions should start during the antenatal period. The results emphasize the importance of abdominal fat mass in the validity of the BMI to predict body fat mass and in the failure of management. The relation of this type of obesity with stunting and with high risk of metabolic syndrome as well as its transmission from one to another generation underline the importance of morbidity and mortality due to malnutrition. This gives more arguments for programs as the IYCF and the «life-cycle» concept. Interventions have to be at different levels and must be objectively estimated.