Sufferers of type 2 diabetes mellitus (T2DM) who quit smoking are likely to see a temporary deterioration in their glycaemic control which could last up to three years, according to new research.
The research team, led by Dr Deborah Lycett of Coventry University and funded by the NIHR School for Primary Care Research (SPCR) examined the primary care records of 10,692 adult smokers with T2DM over six years to investigate whether or not quitting was associated with altered diabetes control.
The study found that in the 3,131 (29%) people who quit and remained abstinent for at least one year, HbA1c – which is an average measurement indicating how well the body is controlling blood glucose levels2 – increased by 2.3mmol/mol (0.21%) before decreasing gradually as abstinence continued (the higher the HbA1c level, the greater the risk of developing diabetes-related complications). In the same period, 5,831 (55%) continual smokers – who did not change their smoking status during the study – experienced a more gradual increase in HbA1c, such that HbA1c levels in quitters became comparable with the levels seen in continual smokers three years after quitting.
The researchers used a regression model which examined each cohort with and without weight change data, concluding that weight changes often associated with quitting smoking did not significantly alter the association between smoking cessation and HbA1c levels.
Lycett from Coventry University's faculty of health and life sciences is quoted as saying: "Knowing that deterioration in blood glucose control occurs around the time of stopping smoking helps to prepare those with diabetes and their clinicians to be proactive in tightening their glycaemic control during this time.
"Stopping smoking is crucial for preventing complications that lead to early death in those with diabetes. So people with diabetes should continue to make every effort to stop smoking, and at the same time they should expect to take extra care to keep their blood glucose well controlled and maximise the benefits of smoking cessation."
[link url="http://www.coventry.ac.uk/primary-news/study-links-quitting-smoking-with-deterioration-in-diabetes-control/?theme=main"]University of Coventry material[/link]
[link url="http://www.thelancet.com/journals/landia/article/PIIS2213-8587(15)00082-0/abstract"]The Lancet Diabetes and Endocrinology article summary[/link]