Incidence of diabetes in patients with schizophrenia: a population-based study.

OBJECTIVE

To detect the incidence of diabetes in patients with schizophrenia in Taiwan.

METHODS

The National Health Research Institute provided a database of 1 million random subjects for study, from which we drew a random sample of 617 068 subjects aged 18 years and older in the year 2000. Subjects who had at least one service claim during this year, with a primary diagnosis of schizophrenia, diabetes, or with a prescription for treatment of diabetes, were identified. We compared initial diagnosis of diabetes between patients with schizophrenia and the general population in 2000. We also followed a cohort of subjects with schizophrenia from 2000 to 2005.

RESULTS

The incidence of diabetes was higher in patients with schizophrenia than in the general population (1.46% and 1.12%, respectively; OR 1.47; 95% CI 1.09 to 1.97) in 2000. Compared with the general population, patients with schizophrenia showed a higher incidence of diabetes in the group aged 18 to 29 years; among females; among those with insurance of more than US$1281; among those living in the northern region; and among those residing in urban areas. The average annual incidence of diabetes in patients with schizophrenia was 1.84% from 2000 to 2005. Higher incidence of diabetes in patients with schizophrenia was associated with increased age, females, hypertension, and hyperlipidemia.

CONCLUSIONS

Patients with schizophrenia had a higher incidence of diabetes for the youngest adult age group and for females than for the general population. Increased age, females, hypertension, and hyperlipidemia were risk factors of diabetes in patients with schizophrenia.