Weight Gain After Smoking Cessation and Risk of Major Chronic Diseases and Mortality

Berhe W Sahle,Andre M N Renzaho,Wen Chen,Lal B Rawal

doi:10.1001/jamanetworkopen.2021.7044

Abstract

Smoking cessation is frequently followed by weight gain; however, whether weight gain after quitting reduces the health benefits of quitting is unclear. To examine the association between weight change after smoking cessation and the risk of cardiovascular diseases (CVD), type 2 diabetes, cancer, chronic obstructive pulmonary disease (COPD), and all-cause mortality. This cohort study analyzed data from a nationally representative sample of Australian adults aged 18 years or older who were studied between 2006 and 2014. Smoking status and anthropometric measurements were self-reported annually. Cox proportional hazards regressions were used to determine the hazard ratios (HRs) for the association between changes in weight and body mass index (BMI) and the risk of CVD, type 2 diabetes, cancer, COPD, and mortality. Data were analyzed in January 2019. Annual self-reported smoking status; years since quitting. Weight gain after quitting, incident CVD, type 2 diabetes, cancer, COPD, and all-cause mortality. Of a total 16 663 participants (8082 men and 8581 women; mean [SD] age, 43.7 [16.3] years), those who quit smoking had greater increases in weight (mean difference [MD], 3.14 kg; 95% CI, 1.39-4.87) and BMI (MD, 0.82; 95% CI, 0.21-1.44) than continuing smokers. Compared with continuing smokers, the HRs for death were 0.50 (95% CI, 0.36-0.68) among quitters who lost weight, 0.79 (95% CI, 0.51-0.98) among quitters without weight change, 0.33 (95% CI, 0.21-0.51) among quitters who gained 0.1 to 5.0 kg, 0.24 (95% CI, 0.11-0.53) among quitters who gained 5.1 to 10 kg, and 0.36 (95% CI, 0.16-0.82) among quitters who gained more than 10 kg. The HRs for death were 0.61 (95% CI, 0.45-0.83) among quitters who lost BMI, 0.86 (95% CI, 0.51-1.44) among quitters without change in BMI, 0.32 (95% CI, 0.21-0.50) among quitters who gained up to 2 in BMI, and 0.26 (95% CI, 0.16-0.45) among quitters who gained more than 2 in BMI. This cohort study found that smoking cessation was accompanied by a substantial weight gain; however, this was not associated with an increased risk of chronic diseases or an attenuation of the mortality benefit of cessation.

Highlights

IntroductionSmoking cessation reduces the risk of major chronic diseases,[1] increases life expectancy,[1,2] and improves quality of life.[2,3] Despite these significant benefits, smoking cessation is often accompanied by increases in weight and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared).[4,5,6] Several mechanisms have been proposed to explain weight gain after smoking cessation, including removal of the appetite-suppressant effects of nicotine, leading to decreased metabolic rate and increased energy expenditure.[7,8] Previous cohort studies[5,9,10] and meta-analyses of observational studies[4,6] have established that smokers who quit gain significantly more weight and BMI than continuing smokers, there is considerable variability in the amount of weight gain after quitting and it may affect health.Excess weight is an established risk factor for several health problems, including type 2 diabetes, cardiovascular diseases (CVD), some cancers, chronic obstructive pulmonary diseases (COPD), and mortality.[11,12,13,14,15] In a study including more than 10 million participants from 239 prospective studies, all-cause mortality was minimal for persons with BMI between 20 and 25; each 5-unit increase in BMI above 25 was associated with a 49%, 38%, and 19% higher risk of CVD, respiratory disease, and cancer mortality, respectively.[13]
The hazard ratios (HR) for death were 0.50 among quitters who lost weight, 0.79 among quitters without weight change, 0.33 among quitters who gained 0.1 to 5.0 kg, 0.24 among quitters who gained 5.1 to 10 kg, and 0.36 among quitters who gained more than 10 kg
This cohort study found that smoking cessation was accompanied by a substantial weight gain; this was not associated with an increased risk of chronic diseases or an attenuation of the mortality benefit of cessation

Summary

Introduction

Smoking cessation reduces the risk of major chronic diseases,[1] increases life expectancy,[1,2] and improves quality of life.[2,3] Despite these significant benefits, smoking cessation is often accompanied by increases in weight and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared).[4,5,6] Several mechanisms have been proposed to explain weight gain after smoking cessation, including removal of the appetite-suppressant effects of nicotine, leading to decreased metabolic rate and increased energy expenditure.[7,8] Previous cohort studies[5,9,10] and meta-analyses of observational studies[4,6] have established that smokers who quit gain significantly more weight and BMI than continuing smokers, there is considerable variability in the amount of weight gain after quitting and it may affect health.Excess weight is an established risk factor for several health problems, including type 2 diabetes, cardiovascular diseases (CVD), some cancers, chronic obstructive pulmonary diseases (COPD), and mortality.[11,12,13,14,15] In a study including more than 10 million participants from 239 prospective studies, all-cause mortality was minimal for persons with BMI between 20 and 25; each 5-unit increase in BMI above 25 was associated with a 49%, 38%, and 19% higher risk of CVD, respiratory disease, and cancer mortality, respectively.[13]. There is a concern that weight or BMI gain after smoking cessation could increase the risk of chronic diseases and potentially attenuate the benefits of quitting smoking.[4,5,17] among smokers, concern about weight gain after smoking cessation is a frequently cited barrier for not trying to quit or for relapsing after quitting attempts.[18]

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