High-intensity smoking linked to diabetes in black patients

Black men and women who smoke more than one pack of cigarettes a day could be as much as 79 percent more likely to develop diabetes mellitus than those who have never smoked, according to a study published this month in the Journal of the American Heart Association.

Smoking and diabetes, though both risk factors for cardiovascular disease, haven’t always been linked to each other, lead author Wendy B. White, PhD, MPH, and colleagues wrote. Research linking smoking to insulin resistance and diabetes has yielded informative results, albeit inconsistent ones, especially in minority groups.

“Despite evidence that smoking is associated with incident diabetes mellitus in certain ethnic groups, little is known about the association of cigarette smoking with diabetes mellitus in blacks, who are disproportionately affected by obesity and diabetes,” the authors wrote.

Previous studies have identified longer smoking duration and lower cessation rates in black smokers when compared to whites, according to the study, and smoking rates in blacks newly diagnosed with diabetes were “significantly higher” than those in whites in the NHANES II (National Health and Nutrition Examination Study) trial.

White et al. enrolled 2,991 black participants for the Jackson Heart Study, all of whom were diabetes-free at the study’s baseline. Patients were self-classified as either current smokers, past smokers or never smokers, with “high-intensity” smoking amounting to 20 or more cigarettes a day.

The original population pool consisted of 361 current smokers—most of whom consumed between 1 and 10 cigarettes a day—502 past smokers and 2,128 never smokers. Over a follow-up period of eight years, 479 people developed incident diabetes mellitus.

White and her team found that high-intensity smokers were nearly 80 percent more likely to develop diabetes than their non-smoking counterparts after eight years. Participants who self-identified as moderate smokers and those who were past smokers saw similar rates of diabetes, according to the research.

There isn’t a specific target group for smoking cessation campaigns, the authors wrote, but knowledge pulled from this study does give clinicians some insight into a particular at-risk population.

“Although smoking cessation should be encouraged for everyone, certain high-risk groups such as blacks who are disproportionately affected by diabetes mellitus should be targeted for cessation strategies,” they said.