Reduced incidence of Type 1 diabetes and Type 2 diabetes in systemic sclerosis: A nationwide cohort study

The purpose of this study is to investigate whether systemic sclerosis is a risk factor for diabetes.

From Taiwan's National Health Insurance Research Database and Registry of Catastrophic Illness database, we enrolled patients with systemic sclerosis and controls. Each systemic sclerosis patient was matched to at most three controls by sex, age, month and year of first diagnosis. Standardized incidence ratio (SIR) of diabetes in systemic sclerosis patients, and 95% confidence interval (95% CI) were calculated. Cox hazard regression was used to calculate the hazard ratio (HR).

A total of 2671 patients with systemic sclerosis and 7769 controls were enrolled. Patients with systemic sclerosis had decreased type 1 diabetes (SIR: 0.18, 95% CI=0.04-0.82). In female groups, systemic sclerosis patients also had lower rates of incident type 1 diabetes (SIR: 0.21, 95% CI=0.05-0.95). Male and female patients with systemic sclerosis both had lower rates of incident type 2 diabetes (SIR: 0.46, 95% CI=0.29-0.72; SIR: 0.41, 95% CI=0.33-0.51, respectively). Systemic sclerosis patients had decreased type 1 diabetes and type 2 diabetes (HR: 0.18, 95% CI=0.04-0.74; HR: 0.42, 95% CI=0.36-0.50, respectively) after adjusting for age and sex.

The results clearly showed that patients with systemic sclerosis had lower incidence of type 1 diabetes and type 2 diabetes compared to control subjects.