Objective: To investigate the prevalence and incidence of non-insulin dependent diabetes (NIDDM) in China by WHO criteria.
Methods: In the prevalence survey of NIDDM all 110660 participants (55391 men, 53269 women) were inhabitants of Daqing City, the largest oil center in northeast China, accounting for 87.3% of the 25 to 74 aged population in this city. They were screened by measuring two-hour plasma glucose concentrations (PG2 h) after a breakfast containing at least 80 g of carbohydrate, then a standard oral glucose tolerance test (OGTT, 75 g glucose load) was performed in 4209 subjects with PG2 h more than 6.67 mmol/L in this screen. NIDDM and impaired glucose tolerance (IGT) were diagnosed using WHO criteria. Incidence survey was made in 36471 non-diabetics identified in the prevalence survey. Two-hour urine-glucose after breakfast was determined during first screen. The urine-glucose trace or positive subjects were then followed by OGTT. Glucose was measured by glucose oxidation method.
Results and conclusions: In prevalence survey, 630 newly diagnosed NIDDM (296 males, 334 females) and 596 IGT (318 males, 278 females) were found in 110660 (male:female = 55391/53269) studied subjects in addition to 190 previously diagnosed NIDDM. Thus the total prevalence of NIDDM was 7.7/1000, and IGT was 5.5/1000. Standardized to the Chinese population in 1982, the prevalences are 12.6/1000 (95% CI = 12.0/1000-13.3/1000) and 7.7/1000 (95% CI = 7.16/1000-8.19/1000) respectively. In the incidence survey, 191 NIDDM (103 males, 88 females) were diagnosed in the 36471 (male:female = 18801/17670) non-diabetics from 1986 to 1990, thus the annual incidence of NIDDM was 131/100000 (137 males, 125 females). Standardized incidence is 131/100000 (95% CI = 94/100000-168/ 100000). It is estimated that there would be more than 700 thousand new diabetics per year in 24-74 years old Chinese if Chinese population were 1.3 billion in the early 21st century.