Women who quit smoking may increase their diabetes risk
MedWire News: Women who quit smoking are at an increased risk for developing diabetes, possibly due to the accompanying weight gain often associated with quitting, report researchers.
However, individuals need to gain at least 5 kg before such a risk increase occurs, they say.
As reported in the Archives of Internal Medicine, Juhua Luo (West Virginia University, Morgantown, USA) and team used data from the Women's Health Initiative, a large prospective study, to investigate the relationships among smoking cessation, weight gain, and subsequent diabetes risk.
Data on weight gain and smoking status at baseline and 3 years were available for 107,471 women. The team divided the women into four groups, according to whether they were never smokers, former smokers, continuing smokers, or new quitters who smoked at baseline but had ceased at follow up.
The researchers then followed up these women over a further 8.5 years for incident diabetes and estimated their risk for developing the condition by smoking status across the overall cohort and stratified by weight gain (categorized as <5 or >5kg).
The researchers report that 10,380 (0.97%) of the women had developed diabetes by the end of follow up.
Multivariate analysis revealed that compared with never smokers, the hazard ratios for incident diabetes for former smokers, continuing smokers, and new quitters, were 1.00, 1.20, and 1.43, respectively.
During the first 3 years of follow up, a weight gain of greater than 5 kg occurred in 10.2% of never smokers, 11.6% of former smokers, 12.3% of continuing smokers, and 30.5% of new quitters.
Further analysis revealed that compared with never smokers, the risk for incident diabetes was similar among new quitters and continuing smokers if they had gained less than 5 kg in weight, at hazard ratios (HRs) of 1.17 and 1.16, respectively.
However, among those who gained 5 kg or more, the HR for diabetes was further increased to a significant 1.67 in those who were new quitters, compared with 1.32 in continuing smokers.
The authors say their findings suggest that the increased risk for diabetes associated with quitting is confined to those who gain at least 5 kg.
"Since weight gain after smoking cessation can be prevented by regular moderate physical activity and dietary modification, smokers should not be deterred form quitting by concerns about an increase in the risk for diabetes," they say.
By Sally Robertson