Liao D, et al. - Via this meta-analysis of prospective cohort studies, researchers—for the first time—assessed the relationship between tobacco smoking and the development of diabetic nephropathy (DN). They analyzed a total of 9 prospective cohort studies, which included > 200,000 participants. Compared with non-smoking participants, current smokers displayed an increased risk of developing DN. According to subgroup analysis, smoking may increase the risk of DN in patients with type 1 diabetes mellitus (T1DM), but does not change the risk in those with type 2 diabetes mellitus. Outcomes, thus, suggested that smoking may be an independent risk factor for DN, especially in patients with T1DM.