The Epidemical Characteristics And Influencing Factors Of Glucose Dysbolism In Schoolchildren Of Beijing

With the improved living standard and the changes in life style in recent years, overweight and obesity are becoming more often seen in children. Meanwhile, the prevalence of impaired glucose regulation (IGR) caused by obesity, including impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and even type2diabetes mellitus (T2DM) which was generally considered to be a disease of adults, is increasing more obviously than before. Diabetes is closely related to cardiovascular disease (CVD) of adults, and is one of the major risk factors for CVD which has become the leading cause of death in China. The younger the age of onset of IGR and T2DM, the higher the risk of developing into CVD in adulthood. Comparing to the individuals with Type1diabetes mellitus (T1DM), adolescents with T2DM develop complications resulted from T2DM earlier and have higher mortality rate. Therefore, IGR and T2DM in children have been drawn more and more attention and is very important medical research subject with the aim of early diagnosis and treatment, which shall be very helpful to decrease the occurrence of DM and CVD among adults. However, few reports on IGR and T2DM of children have been reported and the population-based studies for children and adolescents have not been investigated in Beijing or all over the country till now. Hence, the present research aims at several interesting points as bellow:(1) To discover the distribution characteristics of fasting capillary blood glucose (FCBG) in schoolchildren aged between6-18years in Beijing, China;(2) To investigate the prevalence of IGR and diabetes, especially T2DM among schoolchildren;(3) To discuss the effects of related risk factors such as gender, age, district, family history of diabetes, obesity and related Abnormal metabolism on IGR and T2DM occurrence and (4) To discuss the classification and characteristics of diabetes based on population.This study is a cross-sectional investigation. Randomized cluster sampling method was used to investigate blood glucose levels as well as risk factors of T2DM among19,431schoolchildren aged between6to18from7districts and counties of Beijing. The sample to be studied was determined according to a two-stage cluster sampling. Some measurements such as height, weight, waist circumference, blood pressure, Tanner stage and fasting capillary blood glucose were performed in the first stage. Referring to the screening standard of fasting capillary blood glucose published by WHO in1999, a fasting hyperglycemia group (FCBG>5.6mmol/L) with476subjects was identified. After subscribing the informed consent,226subjects were tested for fasting plasma glucose (FPG), lipid profile and insulin levels in the second stage for clinical diagnosis. Among those subjects,180of them were given oral glucose tolerance test (OGTT) after eating1.75g/kg glucose. Some of them were considered to have DM and pre-diabetes based on ADA diagnosis and classification of diabetes mellitus. Results of plasma glucose testing were categorized as follows:(1) impaired fasting glucose (IFG) requires a fasting plasma glucose (FPG) level higher than5.6to6.9mmol/L, along with a2-hour glucose level <7.8mmol/L in the glucose-tolerance test and (2) impaired glucose tolerance (IGT) requires a fasting glucose level<5.6mmol/L as well as a2-h oral glucose tolerance test (OGTT) value between7.8to11.0mmol/L. DM was defined as a fasting glucose level over7.0mmol/L or2hr postprandial glucose over11.1mmol/L. Diabetes classification is based on the standard of T2DM screening among children and adolescents proposed by ADA and the diagnosis standard by Dean. The antibody test is also taken into consideration at the same time. Children tested with positive antibody will be more possible to be diagnosed as T1DM.After the statistic analysis of all the data mentioned above some results were obtained as follows:1. Distribution characteristics of FCBG in schoolchildren aged between6-18years in Beijing.(1) There are consistent statistical significant differences (P<0.001) in the FCBG between boys and girls, with boys having higher mean concentrations in all age groups. The trend of changes in FCBG of boys and girls with age is almost the same and showing a bimodal pattern. It was found that their FCBG level increased with age between6to11years old to the first peak value, then decreased to a valley till13years old followed by an increase to another peak at15years old, finally decreased continually till18years old. (2) The mean FCBG levels were4.7±0.5and4.6±0.5mmol/L in children from urban and rural areas, respectively. Both the mean FCBG level and BMI in the children from urban area were significantly higher than those from rural area, with P<0.001.(3) The mean FCBG levels for normal weight, overweight and obese children were4.60±0.51,4.69±0.60and4.71±0.56mmol/L, respectively. The mean FCBG level in obese group is significantly higher than that in normal weight group, with P<0.001.(4) Among all the participants, a total of476(2.45%) had FCBG>5.6mmol/L, including321boys (1.65%) and155girls (0.80%). The ratio of boys to girls was2.1:1, and there are statistical significant differences between genders, with P<0.001.(5) The multivariable logistic regression analysis indicated that family history of diabetes, gender, hypertriglyceridemia, acanthosis nigricans and high blood pressure were significantly associated with FCBG elevation.2. Prevalence situation of IGR and diabetes especially T2DM among schoolchildren.(1) On examination, we identified98cases of hyperglycemia including81cases of IFG,6cases of IGT,6cases combined IFG and IGT,16cases of diabetes. Among the16diabetes cases,14were newly identified including6classified as T1DM,6as T2DM and2as other specific types of diabetes. The other two cases were previously diagnosed and reported from the questionnaire by themselves.(2) The prevalence of IFG, IGT and diabetes among schoolchildren were8.78%o,0.65%o and1.52%o, respectively. The prevalence of diabetes was found to be0.91%o in boys and1.97%o in girls.(3) The total prevalence of T2DM in normal population was0.65%o, the total prevalence of IGR was8.89%o, and the total prevalence of T2DM and IGR was10.41%o.(4) The prevalence of T2DM and IGR was1.1%and0.4%respectively in the children of overweight combined with obese and normal weight. The differences are statistically significant, with P<0.001.(5) The multivariable logistic regression analysis confirmed that the factors of family history of diabetes, hypercholesterolemia, acanthosis nigricans. high blood pressure, abdomen obesity, hypertriglyceridemia and gender were significantly associated with IGR and diabetes.(6) Among the14cases of newly identified diabetes,6were classified as T1DM,6as T2DM which were all girls, and another2were classified as other specific types of diabetes. The ratio of T2DM to T1DM was1to1.Some valuable conclusions as follows could be drawn from the above investigations:(1) The fasting capillary blood glucose level for schoolchildren aged6to18in Beijing was correlated with gender, age, obesity and district.(2) The prevalence of IFG, IGT and T2DM in schoolchildren were8.78%o,0.65%。 and0.65%o, respectively. Our study also shows a high prevalence,8.89%o and10.41%o of pre-diabetes and diabetes among schoolchildren in Beijing.(3) We also found that family history of diabetes, hypercholesterolemia, acanthosis nigricans, high blood pressure, abdomen obesity, hypertriglyceridemia and gender were risk factors for impaired glucose regulation and T2DM in children and adolescents.(4) The proportion of T2DM in children diabetes has been found to increase to50%, which should be paid more attention to.In summary, with the increasing number of obese children, diabetes and pre-diabetes among children are increasing and have shown apparent prevalence trend. Because of the close relationship with some diseases in adulthood such as diabetes and CVD etc, diabetes and prediabetes among children is becoming an important public health problem. The investigation on the prevalence situation and characteristics of impaired glucose regulation of children is very important for preventing and treating the disease. At present, the published data related to glucose metabolism based on population among children are very limited both in domestic and abroad. Besides the distribution of blood glucose, the report determined the prevalence of impaired gulcose regulation and diatetes and discussed their rick factors among children as well, which will provide valuable references for further studies related to glucose metabolism in children and adolescents.