Cut-Off Fasting Plasma Glucose Level To Determine Impaired Glucose Metabolism In Obesity

Objective: Our aim was to find out which fasting glucose level should be the cut-off point for impaired glucose metabolism in obese patients. Subjects: 257 patients (195 females, 62 males) whose body mass indexes (BMI) were above 30kg/m² participated in this study. After all cases had underwent a 75gr oral glucose tolerance test (OGTT) the patients were divided into four groups according to their fasting plasma glucose values ( group 1:80-89mg/dl (4.4-4.9mmol/l), group 2:90-99mg/dl (5.0-5.5mmol/l), group 3:100-109mg/dl (5.6-6.0mmol/l), group 4 :110-125mg/dl (6.1-6.9mmol/l) ). According to OGTT results we defined patients as cases who were normal, who had impaired fasting glucose, and who had impaired glucose metabolism (diabetes mellitus and impaired glucose tolerance). Results: No difference was found between age, gender, BMI, systolic and diastolic blood pressure, and lipid profiles of the groups. The number of patients who were diagnosed as impaired glucose metabolism increased apparently in the third group (%50.7) (p<0.05). Mean fasting plasma glucose level of the third group was 104,16±2,73mg/dl (5.78±0,15mmol/l). Although there was no statistically difference between the groups, mean homeostasis model assessment (HOMA) values were above 4 in the third and fourth groups, in the patients who had impaired fasting glucose and impaired glucose metabolism. Conclusion: We think that it is necessary to apply a OGTT to obese patients whose fasting plasma glucose levels are above 104 mg/dl in order to reduce the mortality and morbidity of the cardiovascular diseases.