Cigarette smoking and risk of albuminuria in patients with type 2 diabetes: a systematic review and meta-analysis of observational studies.

BACKGROUND

The aim of this study was to assess the effects of smoking on albuminuria risk in adults with type 2 diabetes mellitus (T2DM).

METHODS

A literature search was conducted using MEDLINE, EMBASE, and China National Knowledge Infrastructure from the established date to October 2017. Summary relative risks (SRR) and 95% confidence intervals (CI) were computed utilizing a random effect inverse variance method.

RESULTS

This meta-analysis included a total of 19 relevant observational studies (four prospective cohort, seven case-control, and eight cross-sectional studies), reporting 105,031 participants and 23,366 albuminuria events. Compared with never-smokers with T2DM, the SRRs of albuminuria were 1.43 (95% CIs 1.27-1.61) for ever-smokers, 2.61 (95% CIs 1.86-3.64) for current smokers, and 1.86 (95% CIs 1.37-2.52) for former smokers. Considerable heterogeneity was observed among these studies, and study design was a significant modifier for this association. There were significantly elevated risk associations for microalbuminuria (SRRs = 1.24, 95% CIs 1.05-1.46) and for macroalbuminuria (SRRs = 1.65, 95% CIs 1.03-2.66), respectively.

CONCLUSIONS

Our systematic review and meta-analysis indicates that cigarette smoking might be a potential factor for the development of albuminuria in adults with T2DM. Future studies are required to investigate the association between smoking cessation and intensity and incident albuminuria in adults with T2DM.