Got Diabetes? Quit Smoking, but Take Care

Type 2 diabetes patients should quit smoking but may need to manage blood sugar more carefully afterward

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) If you smoke, quit! If you're a smoker who has diabetes, however, you may need to more closely monitor your blood sugar after you quit.

New research from Coventry University in the UK found that diabetes patients who quit smoking could have more trouble keeping their blood sugar under control for several years after they quit. The authors of this study said patients should be proactive about their blood sugar during the first few years after quitting smoking.

Lead study author Dr. Deborah Lycett, of Coventry University's Faculty of Health and Life Sciences, said in a press release, "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."

Dr. Lycett and colleagues looked at records of more than 10,600 smokers who also had type 2 diabetes for a six-year period. Of these patients, 3,131 were able to stop smoking completely.

In type 2 diabetes, patients' bodies cannot properly respond to insulin, a hormone that regulates blood sugar. Without proper treatment, this can lead to high blood sugar levels and later kidney and heart disease, among other health problems.

Average blood sugar in people with diabetes is measured by a lab test called the HbA1c. At the end of the first year, the HbA1c of people who quit smoking increased 0.21 percent.

Study patients who did not quit smoking also had an increase in HbA1c, but it took them three years to increase 0.21 percent.

Former smokers with type 2 diabetes continued to have problems with blood sugar control for up to three years after quitting.

People who stop smoking often gain weight. Dr. Lycett and team determined that weight changes — which can also affect HbA1c levels — were not a factor in these blood sugar control problems.

Dr. Lycett and team noted that even small drops in HbA1c levels may decrease the risk of heart failure and circulatory changes in people with type 2 diabetes.

This study was published in the April issue of The Lancet Diabetes & Endocrinology.

The National Institute for Health Research School for Primary Care Research funded this study.

All of the authors except Dr. Paul Aveyard and Dr. Linda Nichols received grants from the National Institute for Health Research School for Primary Care Research during this study. Several authors also received grants or fees from Pfizer and Pierre Fabre Laboratories, which make medications used in diabetes treatment.

Review Date: 
April 29, 2015
Last Updated:
May 5, 2015