The Effect Of Diet, Physical Activity And Peroxisome Proliferators Activated Receptors Gamma C161→T Polymorphism On Obesity And Serum Lipid, Glucose In School Children

The prevalence of overweight obesity in school-aged children not only is increasing in the world, but also dramatically in China. Childhood obesity is significantly related with adverse health problems, such as metabolic disorders, dysfunction of heart, lung and development, and psychosocial complications which include low social acceptance, impaired self-consciousness and so on. And childhood obesity is related to obesity in adult life, which may lead to adverse health problems, such as hypertension, cardiovascular disease. It is generally known that the causes of childhood obesity are mainly both genetic and environmental factors, including but not limited dietary and physical activity.ObjectiveThe purposes of this study were to understand the epidemiological characteristics of overweight and obesity of school-aged children, and further study the individual effect of diet, physical activity and PPAR γC161→T polymorphism on childhood obesity and serum lipid profile, glucose, and the interaction between PPAR γC161→T polymorphism and dietary factor, physical activity in order to provide a theoretical basis for target population of surveillance and prevention measures of childhood obesity.MethodA multistage random cluster sampling technique was used. We randomly selected2classes per grade from3to5in6primary schools in a District, Shanghai. Dietary intake was assessed by a3-consecutive day dietary record including2weekdays and1weekend. Information on exercise-related physical activity was collected by a self-made7day physical activity recall questionnaire. Venous blood specimens were drawn after overnight fasting, and total cholesterol (TCH), triglyceride (TG), low-density lipoprotein-cholesterol(LDL) and high-density lipoprotein-cholesterol (HDL), serum glucose, and insulin were measured. PPAR γ C161→T polymorphism was decided by a method of PCR-RFLP after genome DNA was extracted.Result1. Epidemiological characteristics of school-aged overweight and obesity in a District, ShanghaiThe prevalence of overweight and obesity of school-aged children was10.4%and8.9%, respectively, and the prevalence of boys was higher than that of girls(X2=25.506,P＝0.000).2. The factors related to overweight and obesity of school-aged children(1) The association between dietary factors and overweight/obesity of school-aged childrenThe dietary intake of bean and milk was lower in overweight/obesity children compared to normal those, and risk of overweight/obesity was lower in those whose cereal intake was>300g/d comparing with≤300g/d; the dietary total antioxidant activity(TAC) of normal children was7.92±3.36mmol, whereas overweight/obesity was7.38±3.18mmol, the difference was statistically significant, the risk of overweight/obesity in the first quartile of TAC was highest, and TAC was negatively associated with body weight and waist; healthy dietary pattern obtained by factor analysis was protective factor for children overweight/obesity, and risk of the fourth quartile of healthy dietary pattern was lower than that of Q1(OR (95%CI) was0.615(0.387-0.978)).(2) The association between dietary factors and overweight/obesity of school-aged childrenTotal sedentary time≥28h/w significantly increased the odds of being overweight/obesity compared to<28h/w, and risk of those sleep duration decreased≥9h/d compared with<9h/d, meanwhile, sedentary time was negatively, sleep time positively associated with waist, BMI, and bodyweight.(3) The association between life pattern and childhood overweight/obesity Western life pattern, with longer physical duration, western dietary pattern, shorter sleep duration increased the risk of childhood overweight/obesity; but healthy life pattern with longer physical duration, healthy dietary pattern, and shorter sedentary duration was protective factor.(4) The association between PPAR Y C161→T polymorphism and overweight/obesity of school-aged childrenThe interaction between PPAR γ C161→T polymorphism and gender, cereal intake was statistically significant; T allele was risk factor for girls, but not boys; the effect of PPAR γ C161→T polymorphism on children overweight/obesity was no significant in those cereal intake≤300g/d, but T allele is protective factor in those cereal intake>300g/d; T allele was risk factor in the1st quartile of western life pattern.(4) The multivariate analysis of factors influencing on Children overweight and obesity Multivariate logistic regression analysis showed that age, male, lower TAC, longer sedentary time were risk factors for overweight/obesity of school-aged children, whereas healthy dietary pattern, longer sleep time were protective factors; multivariate linear regression analysis showed the factors affecting BMI were age, gender, walk duration, sleep duration, and those affecting body weight and waist were gender, age, walk, sedentary and sleep duration.3. The physical factors related to lipid and serum glucose of school-aged children(1) Age, gender and lipid and serum glucose of school-aged childrenChildren’s lipid and serum glucose increased along with age, but decreased when age was12, HOMA index and insulin concentration increased with age; TG, LDL, LDL/HDL, TCH/HDL, insulin, HOMA index was higher, but HDL lower, in those overweight/obesity compared to normal children.(2) The association between dietary factors and lipid, serum glucose of school-aged childrenDietary intake of carbonhydrate, fiber, plant protein, cereal, fruits, eggs, percent of carbonhydrate of energy was negative associated with lipid and serum glucose of children, and dietary intake of saturated fat acid, mono unsaturated fat acid, the proportion of supper in energy supply, meat&fish was positively associated with lipid and glucose; healthy dietary pattern was negatively associated with serum glucose in total participants, and western dietary pattern was positively associated with serum glucose.(3) The association between physical activity factors and lipid, serum glucose of school-aged childrenThere was a negative association between walk time, walk times, physical time and serum glucose, but a positive one between homework time, sedentary time and serum glucose.(4) The association between life pattern and childhood serum lipid and glucoseThe western life pattern grades were positively associated with insulin concentration and HOMA index, and the healthy one negatively with serum glucose.(5) The association between PPAR γ C161→T polymorphism and lipid, serum glucose of school-aged childrenThose who have T allele had higher TCH compared with others in total and normal weight participants, but those having T allele had higher TG compared to others in overweight/obesity children; the interaction on TG between PPAR γ C161→T polymorphism and gender was significant, those having T allele had higher TCH and TG level compared to others in female children; children with T allele had higher TG in1st quartile of western and healthy life pattern.(5) Multivariate linear regression analysis of factors influencing on lipid and serum glucose of school-aged childrenThe multivariate linear regression analysis showed the factors affecting TCH, TG, serum glucose, HDL, TCH/HDL, insulin were T allele, homework time, age, gender and healthy dietary pattern, age, homework time, age, respectively.Conclusion1. The level of overweight/obesity of school-aged children was very high, and boys were higher than girls in the rate of overweight/obesity2. Male, lower cereal intake, lower dietary TAC, lower healthy dietary pattern points, longer sedentary duration, shorter sleep time, and PPAR γ C161→T polymorphism were risk factors for children overweight and obesity.3. PPAR γ C161→T variant was risk factor of overweight/obesity in the female,1st quartile of western life pattern, and protective factor in those whose ceareal intake was>300g/d. Therefore, our study provided evidence for target population of surveillance of childhood obesity.4. Lower healthy dietary pattern points, longer sedentary duration, shorter physical duration, and PPAR γ C161→T polymorphism was associated with higher serum lipid and glucose.5. Children who had PPAR γ C161→T variant had higher TCH or/and TG level compared with those with CC type in female,1st children of western and healthy life pattern, and this study offered clues for target population of surveillance of childhood serum lipid.