A new international consensus statement providing evidence-based guidance on smoking cessation for people with type 2 diabetes (T2D) has been issued by a multidisciplinary international panel called the DiaSmokeFree Working Group. 

The central message “is that smoking cessation needs to be treated as an integral part of diabetes management rather than as generic lifestyle advice,” statement co-author Riccardo Polosa, MD, PhD, professor of internal medicine at the University of Catania in Catania, Italy, told Medscape Medical News.

“There is evidence that this is under-prioritized in diabetes care,” he added. “Clinicians understandably focus on glucose, blood pressure, lipids, and medications, while smoking may receive only brief and mostly ineffective advice.”

Smoking is one of the most important modifiable risk factors in people with T2D, yet when we reviewed the existing guidance, we found that major diabetes organizations generally limited their advice to brief recommendations not to smoke, without providing a dedicated, practical pathway for pharmacotherapy, behavioral support, relapse prevention, post-cessation metabolic monitoring, or drug-smoke interactions,” he said.

The DiaSmokeFree Working Group was convened in 2023 by members of CoEHAR, and their 80-page document — “International Consensus Recommendations for Smoking Cessation in Type 2 Diabetes from the DiaSmokeFree Working Group” — was recently published in Diabetes Research and Clinical Practice.

A Comprehensive Look at Smoking and Diabetes

The guideline addresses the epidemiology of smoking, evidence of smoking as a risk factor for T2D, effects of smoking on people with T2D, interventions for smoking cessation including emerging strategies such as GLP-1s and e-cigarettes, barriers to smoking cessation in T2D, and specific health concerns when quitting smoking such as weight gain.

For both patients with and without diabetes, the guidelines suggest that healthcare professionals should routinely ask about smoking habits at every opportunity and discuss possible solutions and that risk assessment tools for diabetes should include smoking status.

For patients with T2D who smoke, smoking cessation should be considered as an important intervention to prevent macrovascular complications, the guidelines suggest.

Recommendations for these patients include the following:

• Offer varenicline as first-line pharmacotherapy, where accessible, to support smoking cessation in people with T2D.
• When varenicline is unavailable or contraindicated, offer nicotine replacement therapy or bupropion for smoking cessation in T2D, noting that the evidence is of moderate certainty and further research is needed to confirm efficacy in this population.
• Offer nonpharmacologic interventions (eg, advice, behavioral counselling, motivational support) to people with T2D who smoke, especially those not ready to quit to build motivation and those intending to quit where expertise and resources exist.
• Prepare patients for transient metabolic changes and arrange early monitoring of glucose, blood pressure, weight, and adverse effects.
• Anticipate drug-smoke interactions and adjust affected medications to reduce hypoglycemia and other adverse outcomes. In particular:
  • Chemicals in tobacco smoke speed up the liver’s breakdown of certain drugs, including pioglitazone, dapagliflozin, and canagliflozin. When the person quits smoking, doses of those drugs may need to be reduced.
  • Coadministration of bupropion or nicotine with metformin or linagliptin can reduce renal clearance and increase plasma concentrations, so those glucose-lowering drug doses may also require adjustment.
• In people with T2D who quit smoking, changes in body weight should be monitored and accompanied by proactive obesity management.
• Glycemic control should be monitored closely, and glucose-lowering medications carefully reviewed in smokers with T2D who quit.
• Integrate cessation pathways into existing diabetes care infrastructures, including automated referrals, electronic prompts, and multidisciplinary coordination.

‘An Important Modifiable Risk Factor’

Asked to comment, Robert Gabbay, MD, PhD, associate professor of medicine at Harvard Medical School in Boston, and former chief scientific and medical officer for the American Diabetes Association, told Medscape Medical News that the document “represents a nice review of the many ways in which smoking is particularly deleterious for people with diabetes.”

The newest information, which is possibly underappreciated, is the section on drug-smoke interactions, Gabbay noted. “It’s unclear how clinically important these are regarding need for medication adjustments,” but it’s good to be aware of them, he said. 

Also asked to comment, Timothy J. Lyons, MD, executive medical director of Diabetes Free South Carolina in Columbia, agreed that the document fulfills an unmet need but said he found it to be long and unwieldy.

“Smoking cessation is a critical part of diabetes management, and recommendations around that can be very helpful. However, this document needs a rewrite to get into something more succinct and readable,” he told Medscape Medical News.

Nonetheless, Gabbay pointed out that “overall, the consensus report continues to remind us that the battle to reduce the number of people with T2D who smoke remains urgent and addressable.”

“Given the baseline increased risk of cardiovascular disease, smoking still represents an important modifiable risk factor,” he concluded.

Polosa reported receiving numerous EU and governmental competitive grants, including U-BIOPRED, AirPROM, and Integral Rheumatology & Immunology Specialists Network. He also reported receiving investigator-initiated grants from the Foundation for a Smoke-Free World and from various pharmaceutical companies, including Pfizer, GlaxoSmithKline, CV Therapeutics, NeuroSearch A/S, and Sandoz. He also reported receiving consultation fees from some of these companies.

Gabbay and Lyons reported having no disclosures.

Miriam E. Tucker is a freelance journalist based in the Washington, DC area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR’s Shots blog, and Diatribe. She is on X @MiriamETucker and BlueSky @miriametucker.bsky.social.