Mild Weight Gain After Quitting Smoking Raises T2DM Risk in Men with NAFLD, Study Reveals

The study, published in Diabetology & Metabolic Syndrome, found that men with NAFLD who gain weight after quitting smoking are at a significantly higher risk of developing type 2 diabetes.

"Among 1,409 NAFLD patients, those who gained 4 kg or more post-cessation experienced up to a six-fold increase in their risk of T2DM compared to current smokers. Effective weight management is essential for NAFLD patients after quitting smoking to help reduce their risk of developing T2DM," the researchers wrote.

NAFLD, a condition characterized by the accumulation of fat in the liver unrelated to alcohol consumption, has been associated with an increased risk of various metabolic disorders, including type 2 diabetes. Chengfu Xu, Zhejiang Provincial Clinical Research Center for Digestive Diseases, Hangzhou, China, and colleagues aimed to investigate the post-cessation T2DM risk in male NAFLD and NAFLD-free smokers in a 7-year cohort study.

The study included male adults who participated in annual health checkups over seven years. Recent quitters were divided into four groups based on their weight gain during follow-up: <0 kg, 0–1.9 kg, 2.0–3.9 kg, and ≥4.0 kg. Cox proportional hazard models, adjusted for various factors, were employed to calculate hazard ratios (HRs) and evaluate the relationship between post-cessation weight gain and the development of type 2 diabetes in both NAFLD and NAFLD-free individuals.

The study led to the following findings:

• At baseline, the study included 1,409 NAFLD and 5150 NAFLD-free individuals.
• During a total of 39,259 person-years of follow-up, 15.8% NAFLD patients and 12.1% NAFLD-free participants quit smoking, with the corresponding means (standard deviations) of post-cessation weight gain being 2.24 kg and 1.15 kg, respectively.
• Among NAFLD individuals, compared to current smokers, the fully adjusted HRs for incident T2DM were 0.41, 2.39, 4.48, and 6.42 for quitters with weight gains < 0 kg, 0.0–1.9 kg, 2.0–3.9 kg, and ≥ 4.0 kg, respectively.
• For NAFLD-free individuals, we only observed a significant association between post-cessation weight gain ≥ 4.0 kg and the risk of incident T2DM.
• Further analysis revealed that the impact of post-cessation weight gain on T2DM risk was not affected by alcohol consumption or obesity status at baseline.

"The findings showed that mild weight gain following smoking cessation markedly raised the risk of type 2 diabetes in men with NAFLD, but not in those without the condition. Consequently, it is advised that individuals with NAFLD focus on managing their weight after quitting smoking to mitigate their risk of developing T2DM," the researchers concluded.

Reference:

Xie, J., Lin, P., Hou, L. et al. Risk of incident type 2 diabetes in male NAFLD and NAFLD-free smokers: a 7-year post-cessation study. Diabetol Metab Syndr 16, 192 (2024). https://doi.org/10.1186/s13098-024-01435-4