Smoking may promote diabetes in middle-age, older adults

Current and former smoking among middle-age and older adults appear to increase the risk of developing type 2 diabetes (T2D), with compounds other than nicotine underlying the detrimental association between smoking and T2D, as reported in a study.

The study included 36,742 participants who were 56–95 years old (mean age 69.8 years, 55.5 percent men). All patients were followed-up for the incidence of T2D or death through linkage to the Swedish National Patient, Prescribed Drug and Death Registers.

Of the participants, 5.5 percent reported current Swedish snuff (snus) use, 38 percent reported former cigarette smoking, and 9 percent reported current smoking. Those reported former and current cigarette smoking tended to be men, somewhat younger, have lower educational attainment, higher alcohol intake, and more snus use and higher coffee consumption compared with the participants who never smoked.

Participants who smoked at baseline also engaged less in physical activity but were less likely to have overweight or obesity than those who never smoked. Meanwhile, those who used snus were younger, had lower educational attainment, were more likely to be men, had higher alcohol intake and coffee consumption, had lower physically activity, and had higher body mass index compared with participants who had not used snus.

In multivariable Cox proportional hazards regression models, former and current smoking were associated with an increased risk of T2D (hazard ratio [HR], 1.17, 95 percent confidence interval [CI], 1.07–1.29 and HR, 1.57, 95 percent CI, 1.36–1.81, respectively). The risk remained elevated for about 15 years after cessation among participants who quit smoking.

Snus use was also associated with an increased T2D risk (HR, 1.29, 95 percent CI, 0.89–1.86).