Different levels of fasting and 2-hour plasma glucose in relation to risk of the metabolic syndrome in individuals with normal glucose tolerance

Abstract

Objective To compare the prevalence of metabolic syndrome (MS) and levels of its components between different fasting plasma glucose(FPG) and 2-hour plasma glucose (2 h PG) after 75 g oral glucose tolerance test(OGTT) in a Chinese cohort with normoglycemia. Methods A diabetes survey was conducted in 2438 individuals aged 25-74 years who lived in Zhanshan Community, Qingdao in 2002. A total of 2109 subjects had complete data on height, weight, blood pressure, waist, body mass index (BMI), FPG, 2 h PG, total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and fasting insulin (FINS). 1341 participants with normoglycemia (FPG FPG). General linear model and Chi-square test were used for statistics. Logistic regression analysis was used to evaluate the odds ratio of having MS. Results The proportion of individuals in subgroup A and B was 42.3% (564/1341) and 57.9% (777/1341), respectively. Compared with individuals in subgroup A, those in subgroup B had higher BMI, waist, systolic blood pressure, diastolic blood pressure, FINS, TG, and Non-HDL-C (P<0.05), after adjusting for age and sex. The prevalence of MS was higher in subgroup B(19.1% (149/777)) than in subgroup A (14.7% (83/564)), the differences were statistically significant(χ2=3.91, P<0.05). Subgroup B was independently associated with increased risk for having MS in a multi-covariate logistic regression model(OR: 1.32, 95% CI: 1.02-1.74). The prevalence of MS was higher in the upper vs bottom quartile of 2 h PG (21.3% vs 11.5%, χ2=12.8, P<0.05). Conclusion Within normoglycemic range, individuals whose 2 h PG levels did not return to below the FPG have higher risk for MS than those did. This should be addressed in identifying high risk population for cardiovascular disease. Key words: Metabolic syndrome; Cardiovascular disease; Glucose tolerance test; Fasting plasma glucose; Two-hour plasma glucose