Dr. Jonas Lidfeldt, the study's lead author stated that, smoking may contribute to diabetes by increasing the body's resistance to the blood-sugar-regulating hormone insulin.

He and his colleagues at Lund University in Sweden report their findings in the journal Diabetes Care.

At the start of the study, all of the women, who were between the ages of 50 and 64, had impaired glucose tolerance, often referred to as "pre-diabetes." All were given advice on diet, exercise and smoking to lower their risk of progressing to diabetes.

By the end of the study, 12 percent had developed type 2 diabetes, with women who lived alone being at greater risk-regardless of biological factors like family history of diabetes, blood pressure and cholesterol levels.

However, when smoking habits were factored in, they appeared to explain a large part of the link between living arrangements and diabetes. Also, diet and drinking habits also seemed to play a role, according to the researchers.