Obesity, independent of diabetes diagnosis, found to increase diabetes risk.
Type 1 diabetes is currently one of the most frequent chronic diseases that develops in children and the cases are increasing annually. Sweden currently has the most type 1 diabetes cases in the world. The causes of type 1 diabetes are poorly understood, but genetic and environmental factors are believed to play a major role. It has also been seen that obesity is rapidly increasing worldwide and many women are obese during pregnancy. Past studies have demonstrated that high BMI prior to pregnancy and weight gain during pregnancy are associated with insulin resistance, obesity, and type 2 diabetes in children. However, limited research is available on this relation in type 1 diabetes.
The following prospective, case-control study aimed to determine how maternal BMI and gestational weight gain affect the risk of type 1 diabetes development in early childhood. The study analyzed 16,179 children ages 0-19 years. Of those, 3,231 children with a type 1 diabetes diagnosis between the years 2000 and 2012 were included from the Swedish National Quality Register for Diabetes in Children (SWEDIABKIDS) and 12,948 control children were included from the Swedish Medical Birth Register (MBR). Diabetes diagnosis was initially determined solely on signs and symptoms and years later further confirmed with diabetic screenings. Children were included in the study if their mothers’ BMI and weight gain was available during pregnancy. Children in the type 1 diabetes group were paired with 4 children in the control group that had the same birth year and day, sex, and birth region in Sweden. Women were placed into one of four groups depending on if they were underweight, normal weight, overweight, or obese.
Results show that mothers of the children with type 1 diabetes diagnosis were more likely to be obese when compared to the mothers of the children in the control group (9% vs 7.7%, P=0.02). Mothers of the diagnosed children were also more likely to have diabetes when compared to the mothers of the children in the control group (2.8% vs 0.8%, P<0.001). Maternal gestational weight gain was not statistically significant between the mothers of the diagnosed children and the mothers of the children in the control group. When comparing the children of the mothers who were not diagnosed with diabetes, results showed that children with diagnoses had more obese mothers compared to the children in the control group (8.8% vs 7.6, P=0.04).
It was also determined that children with obese mothers in early pregnancy had an elevated risk of type 1 diabetes diagnosis (adjusted OR 1.18, 95% CI 1.02, 1.36). Maternal diabetes was found to be the greatest risk factor of type 1 diabetes development in children (adjusted OR 3.31, 95% CI 2.49, 4.40). Although, gestational diabetes increased the risk as well (adjusted OR 1.81, 95% CI 1.08, 3.04). There was a significant difference seen in the ages at which children in the diabetes group developed diabetes in association to maternal BMI (P<0.001). Maternal BMI had a major impact on children who developed diabetes below the age of 10 years but not on children who developed diabetes between the ages of 10 to 14 years.
Overall, the study showed that non-diabetic obese mothers were more likely to have children with type 1 diabetes. Independent of diabetes diagnosis; obese mothers in early pregnancy experienced a significant increase in risk of having children with type 1 diabetes. Maternal obesity was also associated with earlier diabetes diagnosis in children. The highest risk factor for childhood type 1 diabetes onset was maternal diabetes. Although gestational diabetes was found to increase the risk as well. A major strength of the study was the use of the large national registries to obtain data. Limitations include unavailability of paternal obesity, incorrect diagnostic codes could have been entered in the registries, height was self-reported and weight was often self-reported as well, making BMI calculations less accurate.
- Obesity, independent of diabetes diagnosis, increased the risk of having children with type 1 diabetes.
- Maternal obesity increased the risk of having children with an earlier onset of type 1 diabetes.
- Maternal diabetes was associated with the highest risk of having children with type 1 diabetes.
Lindell N, Carlsson A, Josefsson A, et al. Maternal obesity as a risk factor for early childhood type 1 diabetes: a nationwide, prospective, population-based case-control study. Diabetologia. 2017; 0: 1-8.
Graciela Nieto, Pharm. D. Candidate 2018, LECOM School of Pharmacy