Smoking is associated with an increased risk of type 2 diabetes but a decreased risk of autoimmune diabetes in adults: an 11-year follow-up of incidence of diabetes in the Nord-Tr ndelag study

Abstract

Aims/hypothesis We compared the association between smoking habits and later occurrence of type 2 diabetes on the one hand and between smoking and diabetes with autoimmunity on the other hand. Methods We used data from a prospective study of 11-year cumulative incidence of diabetes in the Nord-Trøndelag Health Survey. Results Confirming previous reports, heavy smoking (≥20 cigarettes per day) carried an increased relative risk (RR) of type 2 diabetes (n=738, RR=1.64, 95% CI: 1.12–2.39). In contrast, smoking reduced the risk of latent autoimmune diabetes in adults (LADA) and of traditional type 1 diabetes (LADA n= 81, RR=0.25, 95% CI: 0.11–0.60; type 1 diabetes, n=18, RR=0.17, 95% CI: 0.04–0.73). Conclusions/interpretations The results indicate that nicotine influences autoimmune processes in human diabetes.