The diabetes drug dulaglutide (Trulicity) may significantly lower a woman's risk of substantial weight gain after she has given up smoking, according to a study.

Dulaglutide is known to mimic the effects of the hormone GLP-1 which is naturally produced in the gut in response to food, helping to regulate the amount of glucose in the blood and weight gain.

Women seem to be five times as likely as men to put on a lot of weight after they quit smoking, suggests the data, published in the open-access journal BMJ Nutrition Prevention and Health.

Women also seem to have higher smoking relapse rates than men. And it's been suggested that one of the possible explanations for this is that they may be more concerned about the risk of major weight gain in the wake of quitting, although there's no solid evidence for this, said researchers from the University Hospital Basel in Switzerland.

"Our data suggest that an adjunct dulaglutide treatment could be particularly useful for patients facing a high risk of substantial weight gain after smoking cessation, such as women," said Fabienne Baur, from the Department of Endocrinology, Diabetology and Metabolism, at the University

"Another target group could be individuals of both genders who failed several cessation attempts due to weight gain," Baur added.

A previously published clinical trial showed that compared with dummy treatment, dulaglutide significantly reduced weight gain in those who had given up smoking. But it's not clear if this weight loss is gender specific.

Therefore, the researchers re-analysed the data from this trial to see if there were any gender differences in weight lost or gained in the 12 weeks after trying to quit smoking.

The new trial included 255 adults, 155 of whom were women. The average age ranged from 42 to 44 and the number of cigarettes smoked daily averaged 20 for a period of between 19 and 22 years.

Trial participants were randomly assigned to receive either once weekly jabs of 1.5 mg/0.5 ml dulaglutide or 0.5 ml dummy treatment, plus the smoking cessation drug varenicline 2 mg/day and behavioural counselling for a period of 12 weeks.

After 12 weeks, women on dulaglutide lost around 1-2 kilos compared with weight gain of around 2-2.5 kilos for women in the dummy treatment group.

Men taking dulaglutide shed just over half a kilo compared with weight gain of around 2 kilos among those in the dummy treatment group.

But surprisingly, the positive effects of dulaglutide on weight had no impact on short-term quit rates in either men or women, which were relatively high in both: 98 (63 per cent) in women and 65 (65 per cent) in men (65 per cent), the researchers said.

The risk of weight gain after stopping smoking may change over time or depend on other factors, such as the degree of nicotine dependence or age, the researchers cautioned.