Determinants of normoglycemia and contribution to cardiovascular risk factors in a Chinese population: The Hong Kong Cardiovascular Risk Factor Study

Background: Glucose intolerance is clearly associated with increasing risk of cardiovascular disease, but the association among increasing glycemia and cardiovascular risk factors, angina and coronary heart disease in normoglycemic subjects is less clear, particularly in Chinese. Methods: A total of 2763 subjects were recruited and the prevalence of glucose intolerance investigated, using fasting or 2-h 75-g oral glucose tolerance test (OGTT), glucose levels. Subjects normoglycemic by both criteria were selected and the relationship between glycemia and cardiovascular risk factors investigated using analysis of variance and stepwise multiple linear regression analyses. Results: 1931 (69.9%) subjects were normoglycemic by both tests. After adjustment for age and gender, quartiles of fasting and post-load glucose levels showed a clear positive relationship with cardiovascular risk factors, including obesity, blood pressure and lipid levels (p<0.001 for all). Additionally, other measures of glycemia and insulin resistance also dose-dependently increased with increasing fasting and post-load glucose levels (p<0.001 for all). Stepwise multiple regression showed that in females, age (standardised regression coefficient β (β)=0.23, p<0.001), insulin (β=0.17, p<0.001), waist circumference (β=0.11, p=0.007) were independently associated with fasting glucose levels; and body mass index (β=0.17, p<0.001), age (β=0.15, p<0.001) and triglycerides (β=0.15, p<0.001) were independently associated with post-load glucose levels. In males, age (β=0.19, p<0.001) and insulin (β=0.18, p<0.001) were independently associated with fasting glucose levels; and waist circumference (β=0.17, p<0.001), triglycerides (β=0.16, p<0.001) and insulin (β=0.12, p=0.001) were independently associated with post-load glucose levels.