Weight gain in children possible relation to the development of diabetes

Sammanfattning: Background: The prevalence of overweight and obesity among children has increased the last decades and is now defined as a global epidemic disease by the World Health Organization. Also the incidence of type 1 diabetes has increased and there are some hypothesises that argue there is a connection between overweight/obesity and type 1 diabetes.Aim: The general aim of this thesis was to study factors contributing to the development of overweight and obesity among children and to study possible relations to the development of diabetes.Method: All Babies in Southeast Sweden, ABIS, is a prospective cohort study. The study includes all babies who were born in southeast Sweden between Oct 1st 1997 until Oct1st 1999 and the design was to follow them up to school age in ABIS I and to follow them until 14 years in ABIS II, of the eligible 74 % entered the study. The families have answered questionnaires and biological samples were taken mainly from the children at the different time points: birth, 1 year, 2.5 years, 5 years and 8-9 years. In this thesis studies have been made including the whole cohort, but some studies have also been made involving only a part of the children.Results: The prevalence of overweight and obesity among children in the ABIS study was 12.9% overweight and 2.5 % obese at 5 years of age. One risk factor which appeared to have a great impact on the development of overweight and obesity at 5 years of age was the child’s own BMI at an early age and also the heredity for overweight/ obesity and the heredity for type 2 diabetes. If the father had a university degree, the child was less likely to be obese at 5 years of age. Other factors, such as the parents´ age, if the child had any siblings, and if the child lived with a single parent, did not show any significant correlation to the child’s BMI at 5 years of age.Early nutrition has been studied and no correlation could be found between breastfeeding less than 4 months and the development of overweight/obesity at 5 years of age. The parents answered questions about how frequent the child ate different food at 2.5 years and at 5 years. Intake of sweet lemonade was the only single food which was correlated to a higher BMI in 5 years old children. Porridge seemed to be protective against overweight/ obesity. In one of the studies the physical activity was measured by a step counter. The fewer steps the children were taking, the higher BMI and waist circumference they had. Low physical activity was also associated with a higher C-peptide value and decreased insulin sensitivity. Children who spent more time in front of TV/video had a higher fasting blood glucose value.Conclusions: A strong factor for the development of overweight and obesity among children is the child’s own BMI at an early age and also its heredity for overweight/ obesity and the heredity for type 2 diabetes. Early nutrition did not show any obvious correlations with overweight and obesity at 5 year old children. Low physical activity was associated with higher fasting C-peptide value and decreased insulin sensitivity. Low physical activity may cause ?-cell stress which might contribute to an autoimmune process in individuals genetically predisposed to autoimmunity and, thereby, to the increasing incidence of Type 1 diabetes in children.