Objective  To explore the association of smoking amount with the prevalence of type 2 diabetes mellitus (T2DM) among male smokers.

  Methods  We conducted a questionnaire survey, physical examination and laboratory tests among 6 150 residents aged 18 – 79 years and recruited with multistage random sampling in Zhongshan city of Guangdong province between July and December 2016. We adopted restricted cubic spline model and logistic regression to assess the association of smoking amount with T2DM among male smokers.

  Results  The smoking rate in the all participants was 18.24% and that in the male participants was 38.16%. The prevalence of T2DM in the all participants 5.48%, and that in the male smokers 6.13%. The results of multivariate logistic regression analysis revealed that that current smoking was a significant risk factor of T2DM, with the odds ratio OR of 1.45 (95% confidence interval 95% CI: 1.10 – 1.92) after adjusting for age, permanent residence address, marital status, body mass index, education, and average household monthly income and the OR of 1.43 (95% CI: 1.10 – 1.90) after adjusting for age, permanent residence address, marital status, body mass index, education, average household monthly income, and hypertension history. The restrictive cubic spline (RCS) model analysis indicated a non-linear dose-response correlation of number of cigarette smoked per day and smoking index (number of cigarette smoked per day multiplied by year of smoking) with T2DM among male smokers (P < 0.05).

  Conclusion  Smoking amount correlates with the incidence of type 2 diabetes mellitus among male smokers.