Genetic predisposition to Obesity leads to risk of type 2 Diabetes

Genetic Predisposition to Obesity leads to increased risk of type 2 Diabetes
H. Zhao and J. Luan
PubMed
Heather L. Mayer

Obesity is a major risk factor for type 2 diabetes. Recent genetic studies have identified that BMI and risk of obesity are linked to multiple loci. Little information is provided about obesity and its association with type 2 diabetes. Type 2 diabetes results from genetics and environmental factors. It has been determined that being overweight or obese is a major risk factor for type 2 diabetes. The rapid increase in obesity has contributed to the rising prevalence of type 2 diabetes over the last three decades. (Zhao) It is not known whether specific DNA sequences of obesity increase the risk of diabetes because not all obese individuals have type 2 diabetes and vice versa. The goal of this study was to examine the associations of the 12 obesity specific DNA sequences with the risk of developing type 2 diabetes. The methods of this study involved individuals from Norwich between the ages 39-79 who has DNA available for genotyping, the process of examining DNA sequences. Of the individuals, the experimenters excluded any of the participants with missing data about their age, sex and BMI. There were 12 specific DNA sequences that the researchers were looking for with a SNP, single nucleo-tide polymorphism, which is just a sequence of DNA with an error. 20,428 individuals were genotyped at the 12 SNPs. There was a follow up of an average of 12.9 years during which 739 individuals developed type 2 diabetes. A genetic predisposition score was calculated by adding the BMI with the incidence of type 2 diabetes. Of the 12 SNPs, eight showed a trend with increased risk of type 2 diabetes meaning that eight DNA sequences specific to obesity have been shown to be prone to diabetes. The conclusion that the experimenters derived from this study was that the genetic predisposition to obesity leads to increased risk of developing type 2 diabetes which is completely regulated by its “obesity-predisposing effect.” (Zhao)
I found this article to be interesting because with all the commotion about the obesity in American and the prevalence of type 2 diabetes, I have always questioned what caused this relation. Prior to taking a genetics course I most likely would not have grown to appreciate what scientist/researchers can prove or show with examining ones DNA. It is remarkable to know that there are specific sequences in our DNA that can determine a predisposition to a medical condition. From reading this research article I learned that there are specifically 12 SNPs, altered DNA sequences, that are directly correlated with the prevalence of obesity and of those 12 SNPs, 8 of them show a direct correlation with a predisposition to type 2 diabetes. I still question though how with diet regulation and exercise, how a once obese person who becomes lean and fit no longer suffers from type 2diabetes. What is it about losing weight and eating better changes the diabetes if the DNA sequences remain the same?