Aims/hypothesis  

Epidemiological evidence shows an increasing prevalence of type 2 diabetes in Taiwan. The aim of this study was to assess the yearly incidence for this country during 1992–1996.

Subjects and methods  

Data obtained by telephone interviews of 93,484 diagnosed diabetic patients enrolled in Taiwan’s National Health Insurance programme formed the basis of this study. A total of 36,153 incident cases of type 2 diabetes (17,097 men and 19,056 women) were identified and incidence rates calculated. The trends of obesity and parental diabetes were also evaluated.

Results  

The overall 5-year incidences for men and women were 187.1 and 218.4 per 100,000 population, respectively. The trends from 1992–1996 were increased for all age groups in men and for most age groups in women. A 2.8-fold increase in incidence was observed for the youngest age group (<35 years), in which the increase in incidence was higher than in the older age groups. Men showed a higher fold increase in incidence than did women (3.5 vs 2.1). Obesity at interview increased from 39.2% in 1992 to 47.6% in 1996 (p<0.001) and was significant for all ages. Parental diabetes showed no yearly change when all patients were analysed together, but there was a trend towards a decrease in the youngest age group (<35 years) and a trend towards an increase in the oldest age groups (≥55 years).

Conclusions/interpretation  

An increasing incidence of diagnosed type 2 diabetes was observed for each sex in most age groups in Taiwan, but was most marked in the youngest age group. A parallel increase in obesity was observed with the increasing incidence of diabetes.