Smoking cessation may increase diabetes risk

Cigarette smoking is a well-known risk factor for type 2 diabetes, but new research suggests that quitting the habit may actually raise diabetes risk in the short term.

The researchers from Johns Hopkins University suspect that the elevated diabetes risk is related to the extra pounds people typically put on after giving up cigarettes and caution that no one should use the study's results as an excuse to keep smoking.

Study leader Hsin-Chieh ‘Jessica' Yeh, an assistant professor of general internal medicine and epidemiology at the Johns Hopkins School of Medicine, said: ‘The message is don't even start to smoke. If you smoke, give it up. That's the right thing to do. But people have to also watch their weight.'

In the study, researchers found that people who quit smoking have a 70% increased risk of developing type 2 diabetes in the first six years without cigarettes as compared to people who never smoked.

The risks were highest in the first three years after quitting and returned to normal after 10 years.

Among those who continued smoking over that period, the risk was lower, but the chance of developing diabetes was still 30% higher compared with those who never smoked.

The study enrolled 10,892 middle-aged adults, from 1987 to 1989, who did not yet have diabetes. The patients were followed for up to 17 years, and data about diabetes status, glucose levels, weight and more were collected at regular intervals.

Type 2 diabetes is a common disease that interferes with the body's ability to properly use sugar and to regulate and properly use insulin, a substance produced by the pancreas that normally lowers blood sugar during and after eating.

In type 2 diabetes, also known as adult-onset diabetes, the pancreas makes plenty of insulin to help the body when food is eaten, but the body cannot use it normally. The result is excess levels of blood sugar, which, over time, can lead to blindness, kidney failure, nerve damage and heart disease. Overweight people and those with a family history of the disease have an increased risk for developing it, as do smokers, though the causal relationship is unclear.

According to the study, those who smoked the most and those who gained the most weight had the highest likelihood for developing diabetes after they quit.

On average, over the first three years of the study, quitters gained about 8.4 pounds and saw their waist circumferences grow by approximately 1.25 inches.

Yeh and her team said that they want physicians to keep these findings in mind when they are consulting with patients who are giving up cigarettes, especially the heaviest smokers.

They recommend considering counter measures such as lifestyle counselling, aggressive weight management and the use of nicotine-replacement therapy, which seems to blunt the weight gain related to quitting.