Active and Passive Smoking 'Increase Risk of Type 2 Diabetes'
Active and passive smoking both increase the risk of Type 2 diabetes, a huge review of study data on almost six million people has found.
In those who quit, the risk decreases over time, the research shows.
Scientists pooled together the results of 88 studies which between them had nearly six million participants.
Compared with never smoking, a current habit raised the risk of Type 2 diabetes by 37%. Passive smoking was associated with a 22% increased risk and former smoking with a 14% increased risk.
The findings are published in The Lancet Diabetes & Endocrinology journal.
Professor An Pan, from Huazhong University of Science and Technology in China, and colleagues wrote: "In view of the high prevalence of smoking in many countries and the increasing burden of diabetes worldwide, reducing tobacco use should be prioritised as a key public health strategy, which could potentially contribute to prevention and control of diabetes.''
The authors added that a short-term increased risk of diabetes seen in recent quitters needed to be further investigated.
Writing in a linked comment, five experts led by Professor Naveed Sattar, from the University of Glasgow, said: "As well as being a risk factor for cardiovascular disease and many cancers, smoking should also be regarded as a risk factor for diabetes.
"Patients who smoke should also be informed that stopping smoking and maintaining long-term abstinence will not only lessen their cardiovascular and cancer risks, but over time might also lessen their diabetes risk.''