Phenotypical Classification of Type 2 Diabetes Mellitus

Obesity is believed to be the major contributing factor for type 2 diabetes. Obese subjects have 2-3 fold higher risk of developing type 2 diabetes. Obesity in type 2 diabetes increases the risk of hypertension, dyslipidemia and cardiovascular diseases. The current study was aimed to classify type 2 diabetic patients phenotypically based on the obesity indices and to study the prevalence of each phenotype. Methodology: This study included 336 type 2 diabetic patients who attended Kasturba Medical College Hospital, Mangalore. Their waist circumference and body mass index were measured. Based on these measurements they were classified into four phenotypes as follows: Generalized obesity: high values of waist circumference and body mass index. Truncal obesity: high values of waist circumference and normal body mass index. Non-obesity: Normal values of waist circumference and body mass index. The details of glycaemic index, anti-diabetic drug usage, and diabetic complications exhibited were collected from case records. Results: 71% (n=238) of type 2 diabetic patients had generalized obesity, 16% (n=54) of type 2 diabetic patients had truncal obesity, and 13% (n=44) of type 2 diabetic patients were non-obese/lean. There was no significant difference in the HbA1c level between obese and non-obese diabetics. Conclusion: Among the three phenotypes of type 2 diabetes, generalized obesity appears to be the highly prevalent phenotype.