Analysis of relationship between fasting blood sugar levels and insulin resistance

Objective To analyze the relationship between different fasting blood sugar levels and insulin resistance and to explore the rationality of adult impaired fasting blood glucose cut point downward.Methods The grouping control study was adopted and the population receiving physical examination in the Physical Examination Center of Yancheng City No.1 People's Hospital in Jiangsu Province from January 2008 to January 2009 were selected as the study subjects.The subjects were divided into four groups according to the fasting blood sugar level.Basic physical examination and the oral glucose tolerance test were conducted and the 2-hour plasma glucose(2 h PG) was mea sured.The homeostasis model assessment insulin resistance index(HOMA-IR) and the homeostasis model assessment islet beta-cell function(HOMA-B) were calculated using the homeostasis model assessment(HOMA).The relationship between the fasting blood sugar level and the insulin resistance was investigated using analysis of variance and partial correlation analysis.Results With the increase of fasting blood glucose,body mass index(BMI),waist circumference(WC),triglyceride(TG),fasting insulin(FINS),2 h PG gradually increased,with statistically significant difference with the fasting plasma glucose 5.6 mmol/L group(P 0.05),but the 6.1 mmol/L≤FPG7.0 mmol/L group and the 5.6 mmol/L≤ FPG6.1 mmol/L group were not significantly different in BMI,WC,TG,FINS and 2 h PG(P 0.05).Partical correlation analysis showed that the imparied fasting blood glucose under the new cut point(5.6 mmol/L ≤FPG7.0 mmol/L) was in significant positive correlation to HOMA-IR(r = 0.52,P 0.01) but in negative correlation to HOMA-B(r =-0.34,P 0.01).Conclusion The population with FPG from 5.6 to 6.1 mmol/L has already undergone obvious insulin resistance and islet B cell hypofunction and is a high-risk population of type 2 diabetes(T2DM),thus the down-regu lation of cut point is rational.Impaired fasting blood glucose under new cut point is in significant positive correlation to HOMA-IR but in negative correlation to HOMA-B.Insulin resistance is an independent risk factor for impaired fasting blood glucose.