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Smoking and coronary heart disease in patients with type 2 diabetes mellitus
diabetes research and clinical practice
x x x (2 0 1 7) x x x–xxx
Contents available at ScienceDirect
Diabetes Research and Clinical Practice journal homepage: www.elsevier.com/locat e/dia bre s
Smoking and coronary heart disease in patients with type 2 diabetes mellitus Tomoyuki Kawada Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan
Li et al. evaluated the associations of alcohol consumption, tobacco smoking, hypertension, obesity, depression and sleep duration with coronary heart disease (CHD) development among patients with type 2 diabetes mellitus (T2D) with special reference to the gender differences [1]. By logistic regression analysis, the odds ratios (ORs) (95% confidence intervals (CIs)) of female, older age (65), past smoking, long sleep duration, hypertension, and high cholesterol level were 0.51 (0.35–0.74), 1.95 (1.36–2.79), 1.76 (1.22–2.52), 1.7 (1.05–2.77), 3.49 (2.31–5.29) and 1.76 (1.25–2.48), respectively. There was a gender difference in significant ORs except hypertension. I have some concerns on their study. First, past smoking, not current smoking, was selected as a significant independent variable for predicting CHD in men. Although the authors did not present explanation on this point, I speculate that obesity would become a confounding factor on the association. By univariate analysis, obesity was not selected as a significant variable and it was not used in multivariate analysis. By overviewing the recent metaanalysis [2] and a large prospective study [3], current smoking was significantly associated with cardiovascular events and CHD incidence. In addition, stop smoking showed subsequent lower CHD incidence [3]. Duration of smoking cessation should be considered in combination with obesity. Second, American Diabetes Association recently recommended the lifestyle management in patients with diabetes [4], and tobacco control and alcohol consumption were evaluated as important components. Although intervention of smoking cessation has some difficulty to achieve [5], I strongly recommend patients with T2D to quit smoking to prevent diabetic complications. Finally, Pan et al. conducted a systematic review with meta-analysis and concluded that active and passive smoking were associated with significantly increased risks of T2D [6]. Although the risk of T2D was increased in new quitters,
subsequent decrease of the risk was observed as the time since quitting increased. As smoking relates to the incidence of T2D and T2D complications, urgent action of stop smoking should be considered as a public health problem.
Conflicts of interest None.
R E F E R E N C E S
[1] Li L, Gong S, Xu C, Zhou JY, Wang KS. Sleep duration and smoking are associated with coronary heart disease among US adults with type 2 diabetes: gender differences. Diabetes Res Clin Pract 2017;124:93–101. [2] Pan A, Wang Y, Talaei M, Hu FB. Relation of smoking with total mortality and cardiovascular events among patients with diabetes mellitus: a meta-analysis and systematic review. Circulation 2015;132(19):1795–804. [3] Barengo NC, Teuschl Y, Moltchanov V, Laatikainen T, Jousilahti P, Tuomilehto J. Coronary heart disease incidence and mortality, and all-cause mortality among diabetic and nondiabetic people according to their smoking behavior in Finland. Tob Induc Dis 2017;15:12. [4] American Diabetes Association. Lifestyle management. Diabetes Care 2017;40(Suppl 1):S33–43. [5] Nagrebetsky A, Brettell R, Roberts N, Farmer A. Smoking cessation in adults with diabetes: a systematic review and meta-analysis of data from randomised controlled trials. BMJ Open 2014;4(3):e004107. [6] Pan A, Wang Y, Talaei M, Hu FB, Wu T. Relation of active, passive, and quitting smoking with incident type 2 diabetes: a systematic review and meta-analysis. Lancet Diabetes Endocrinol 2015;3(12):958–67.
http://dx.doi.org/10.1016/j.diabres.2017.09.004 0168-8227/Ó 2017 Elsevier B.V. All rights reserved.
Please cite this article in press as: Kawada <. Smoking and coronary heart disease in patients with type 2 diabetes mellitus. Diabetes Res Clin Pract (2017), http://dx.doi.org/10.1016/j.diabres.2017.09.004
x x x (2 0 1 7) x x x–xxx
Contents available at ScienceDirect
Diabetes Research and Clinical Practice journal homepage: www.elsevier.com/locat e/dia bre s
Smoking and coronary heart disease in patients with type 2 diabetes mellitus Tomoyuki Kawada Department of Hygiene and Public Health, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-Ku, Tokyo 113-8602, Japan
Li et al. evaluated the associations of alcohol consumption, tobacco smoking, hypertension, obesity, depression and sleep duration with coronary heart disease (CHD) development among patients with type 2 diabetes mellitus (T2D) with special reference to the gender differences [1]. By logistic regression analysis, the odds ratios (ORs) (95% confidence intervals (CIs)) of female, older age (65), past smoking, long sleep duration, hypertension, and high cholesterol level were 0.51 (0.35–0.74), 1.95 (1.36–2.79), 1.76 (1.22–2.52), 1.7 (1.05–2.77), 3.49 (2.31–5.29) and 1.76 (1.25–2.48), respectively. There was a gender difference in significant ORs except hypertension. I have some concerns on their study. First, past smoking, not current smoking, was selected as a significant independent variable for predicting CHD in men. Although the authors did not present explanation on this point, I speculate that obesity would become a confounding factor on the association. By univariate analysis, obesity was not selected as a significant variable and it was not used in multivariate analysis. By overviewing the recent metaanalysis [2] and a large prospective study [3], current smoking was significantly associated with cardiovascular events and CHD incidence. In addition, stop smoking showed subsequent lower CHD incidence [3]. Duration of smoking cessation should be considered in combination with obesity. Second, American Diabetes Association recently recommended the lifestyle management in patients with diabetes [4], and tobacco control and alcohol consumption were evaluated as important components. Although intervention of smoking cessation has some difficulty to achieve [5], I strongly recommend patients with T2D to quit smoking to prevent diabetic complications. Finally, Pan et al. conducted a systematic review with meta-analysis and concluded that active and passive smoking were associated with significantly increased risks of T2D [6]. Although the risk of T2D was increased in new quitters,
subsequent decrease of the risk was observed as the time since quitting increased. As smoking relates to the incidence of T2D and T2D complications, urgent action of stop smoking should be considered as a public health problem.
Conflicts of interest None.
R E F E R E N C E S
[1] Li L, Gong S, Xu C, Zhou JY, Wang KS. Sleep duration and smoking are associated with coronary heart disease among US adults with type 2 diabetes: gender differences. Diabetes Res Clin Pract 2017;124:93–101. [2] Pan A, Wang Y, Talaei M, Hu FB. Relation of smoking with total mortality and cardiovascular events among patients with diabetes mellitus: a meta-analysis and systematic review. Circulation 2015;132(19):1795–804. [3] Barengo NC, Teuschl Y, Moltchanov V, Laatikainen T, Jousilahti P, Tuomilehto J. Coronary heart disease incidence and mortality, and all-cause mortality among diabetic and nondiabetic people according to their smoking behavior in Finland. Tob Induc Dis 2017;15:12. [4] American Diabetes Association. Lifestyle management. Diabetes Care 2017;40(Suppl 1):S33–43. [5] Nagrebetsky A, Brettell R, Roberts N, Farmer A. Smoking cessation in adults with diabetes: a systematic review and meta-analysis of data from randomised controlled trials. BMJ Open 2014;4(3):e004107. [6] Pan A, Wang Y, Talaei M, Hu FB, Wu T. Relation of active, passive, and quitting smoking with incident type 2 diabetes: a systematic review and meta-analysis. Lancet Diabetes Endocrinol 2015;3(12):958–67.
http://dx.doi.org/10.1016/j.diabres.2017.09.004 0168-8227/Ó 2017 Elsevier B.V. All rights reserved.
Please cite this article in press as: Kawada <. Smoking and coronary heart disease in patients with type 2 diabetes mellitus. Diabetes Res Clin Pract (2017), http://dx.doi.org/10.1016/j.diabres.2017.09.004