Negative Impact Of Smoking For Those with Diabetes

Previous research into smoking and diabetes supports the findings of the newly published study report. Numerous studies indicate that smoking worsens the prognosis of patients and it has been shown to increase the incidence of depression. It also increases the risks of coronary heart disease (CHD), increases the possibility of both microvascular and macrovascular complications, and is associated with inflammation, insulin resistance, and dyslipidemia, a disorder of lipoprotein metabolism that increases bad low-density lipoprotein (LDL) cholesterol and decreases the good high-density lipoprotein (HDL) cholesterol in the blood. 

Ironically though, the proof that smoking is a modifiable risk factor does not appear to have made a major impact on diabetic smokers — yet. Generally research (including the latest study) shows that less than half of smokers with diabetes quit. Worse, there is evidence that a large percentage of clinicians and doctors do not warn their diabetic patients about the advisability of stopping or at least cutting down on smoking. 

What Research Tells Us About Smoking And Diabetes

While research studies over the years have tended to have a different focus to one another, it is clear from overall results that never smoking is the best option in terms of helping to avoid type 2 diabetes. 

A relatively early study (1), published by the British Medical Journal in 2000 looked at the risks for type 2 diabetic patients that are associated with glycaemia. The primary concern of researchers related to macrovascular and microvascular complications, but other complications including stroke, were considered. They found that “any end point or deaths related to diabetes and all cause mortality.” So this is a real concern for diabetics quitting smoking.

Another British study (10) published in 2001 attempted to determine whether smoking accelerated the onset of diabetes mellitus and whether quitting cigarettes could reverse diabetes. Data from 709,827 people older than 30, who had been involved in a cancer prevention study, was used. It found that as these people had increased their smoking habits, the rate of diabetes also increased. When they quit, it took five years (for women) and 10 years (for men) to reduce their diabetes rate to that of people who didn’t smoke.

A US study, Diabetic Patients Who Smoke: Are They Different? Published in 2004 (3) highlighted the importance of encouraging diabetics to quite smoking. While relatively few people (under 2,000) were involved in the study, researchers found that diabetic patients who smoke get more depressed than others.

A study by Arshag D Mooradia on the occurrence of dyslipidemia in T2DM, published in 2009 (4) found this disease to be a major risk factor for CVD in patients with type 2 diabetes. He emphasized the major risks of mortality, though did not discuss smoking.

A nine-year study (5) published in 2010 involved 10,892 middle-aged adults who did not have diabetes, but who did smoke. Researchers found that 1,254 of them developed type 2 diabetes and that the highest risk for those who quit because of this, was in the first three years. This tallies with the new study findings.

Another study (6) that focused specifically on smoking and T2DM was published in the Diabetes & Metabolism Journal (dmj) in 2012. Undertaken by Sang Ah Chang in Korea, it covered a wide range of factors linking diabetes and smoking, and quoted many more studies undertaken in various parts of the world. 

A 10-year study in Japan (7) published in 2012 looked at similar issues to the newly published study quoted earlier, including possible risk factors of quitting as well as weight gain. A total of 59,834 diabetic adults were involved in the study, and again, there was found to be an increased risk when they quit. While weight was not an issue, heavier smokers were found to be more at risk.

Another Japanese study published in 2012 (8) looked at the impact of diabetics quitting smoking, and linked this to weight. The study took more than nine years and involved 2,070 non-smokers, smokers, and men who had previously smoked, none of whom had diabetes. A relatively small number (246) developed diabetes and those who quit were found to be at risk in terms of becoming overweight.  

An American study published in 2013 (9) looked at the association of weight change and smoking cessation in adults with cardiovascular disease (CVD), some of whom had diabetes. A major concern was that while smoking reduces the risk of CVD, it often leads to weight gain that is counter-productive, and can itself increase CVD risks. Data was collected between 1984 and 2011 and analyzed over six-year periods in terms of smoking, non-smoking, and quitting. Even though non-smokers tended to gain more weight, diabetics were at greater risk of CVD “events.”

READ Tobacco Health Impact: A Day without Smoking 

As Sang Ah Chang concluded in his research paper (6), it is essential to educate patients attending diabetic clinics about the importance of not smoking cigarettes. It is also vital to encourage programs that help diabetics stop smoking and manage their illness proactively. Forget the Catch 22!