Adrienne L Johnson1,2, Naomi C Nystrom3,4, Megan E Piper2, Jessica Cook1,2, Derek L Norton5, Megan Zuelsdorff6,7, Mary F Wyman3, Susan Flowers Benton6,8, Nickolas H Lambrou3, John O'Hara9,10, Nathaniel A Chin6,9, Sanjay Asthana3,6,9,11, Cynthia Carlsson3,6,9,11, Carey E Gleason3,6,9. 1. William S. Middleton Memorial Veterans Hospital, Madison, WI, USA. 2. Center for Tobacco Research and Intervention, University of Wisconsin, Madison, WI, USA. 3. VA Geriatric Research, Education and Clinical Center (GRECC), William S. Middleton Memorial Veterans Hospital, Madison, WI, USA. 4. Department of Human Services - State of Minnesota, Anoka, MN, USA. 5. Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. 6. Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA. 7. School of Nursing, University of Wisconsin, Madison, WI, USA. 8. College of Nursing and Allied Health, Department of Rehabilitation and Disability Studies, Southern University and A&M College, Baton Rouge, LA, USA. 9. Division of Geriatrics, Department of Medicine, University of Wisconsin School of Medicine & Public Health, Madison, WI, USA. 10. Institute of Living/Hartford Hospital, Hartford, CT, USA. 11. Wisconsin Alzheimer's Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
Abstract
BACKGROUND: To fully characterize the risk for dementia associated with cigarette smoking, studies must consider competing risks that hinder the observation of dementia or modify the chance that dementia occurs (i.e., death). Extant research examining the competing risks fails to account for the occurrence of death following dementia, limiting our understanding of the relation between smoking and dementia. OBJECTIVE: Examine the impact of smoking status, lifetime smoking exposure, and duration of abstinence on incident dementia, death following dementia, and death without dementia. METHODS: Multi-state models estimated hazard ratios (HR) for 95% confidence interval (CI) of 10,681 cognitively healthy adults for transition from baseline to dementia, baseline to death, and dementia to death based on smoking status, lifetime cigarette exposure, and abstinence duration. RESULTS: Compared to never smokers, current smokers had increased risk of dementia (HR = 1.66; 95% CI 1.18- 2.32; p = 0.004), and death from baseline (HR = 2.98; 95% CI 2.24- 3.98; p < 0.001) and incident dementia (HR = 1.88; 95% CI 1.08- 3.27; p = 0.03). Pack years increased risk of death from baseline (HR = 1.01; 95% CI 1.00- 1.01; p < 0.001), but not dementia risk (HR = 1.00; 95% CI 1.00- 1.00; p = 0.78) or death following dementia (HR = 1.01; 95% CI 1.00- 1.01; p = 0.05). Recent quitters (quit < 10 years), compared to never smokers, had increased risk of death after baseline (HR = 2.31; 95% CI 1.55- 3.43; p < 0.001), but not dementia (HR = 1.17; 95% CI 0.73- 1.88; p = 0.52) or death following dementia (HR = 1.01; 95% CI 0.42- 2.41; p = 0.99). CONCLUSION: Current smoking increases the risk for dementia and death, but dementia is better attributed to smoking recency than lifetime exposure. Smoking cessation at any age might reduce these risks for cognitively healthy individuals.
BACKGROUND: To fully characterize the risk for dementia associated with cigarette smoking, studies must consider competing risks that hinder the observation of dementia or modify the chance that dementia occurs (i.e., death). Extant research examining the competing risks fails to account for the occurrence of death following dementia, limiting our understanding of the relation between smoking and dementia. OBJECTIVE: Examine the impact of smoking status, lifetime smoking exposure, and duration of abstinence on incident dementia, death following dementia, and death without dementia. METHODS: Multi-state models estimated hazard ratios (HR) for 95% confidence interval (CI) of 10,681 cognitively healthy adults for transition from baseline to dementia, baseline to death, and dementia to death based on smoking status, lifetime cigarette exposure, and abstinence duration. RESULTS: Compared to never smokers, current smokers had increased risk of dementia (HR = 1.66; 95% CI 1.18- 2.32; p = 0.004), and death from baseline (HR = 2.98; 95% CI 2.24- 3.98; p < 0.001) and incident dementia (HR = 1.88; 95% CI 1.08- 3.27; p = 0.03). Pack years increased risk of death from baseline (HR = 1.01; 95% CI 1.00- 1.01; p < 0.001), but not dementia risk (HR = 1.00; 95% CI 1.00- 1.00; p = 0.78) or death following dementia (HR = 1.01; 95% CI 1.00- 1.01; p = 0.05). Recent quitters (quit < 10 years), compared to never smokers, had increased risk of death after baseline (HR = 2.31; 95% CI 1.55- 3.43; p < 0.001), but not dementia (HR = 1.17; 95% CI 0.73- 1.88; p = 0.52) or death following dementia (HR = 1.01; 95% CI 0.42- 2.41; p = 0.99). CONCLUSION: Current smoking increases the risk for dementia and death, but dementia is better attributed to smoking recency than lifetime exposure. Smoking cessation at any age might reduce these risks for cognitively healthy individuals.
Authors: Erin L Abner; Peter T Nelson; Gregory A Jicha; Gregory E Cooper; David W Fardo; Frederick A Schmitt; Richard J Kryscio Journal: J Alzheimers Dis Date: 2019 Impact factor: 4.472
Authors: Lilah Besser; Walter Kukull; David S Knopman; Helena Chui; Douglas Galasko; Sandra Weintraub; Gregory Jicha; Cynthia Carlsson; Jeffrey Burns; Joseph Quinn; Robert A Sweet; Katya Rascovsky; Merilee Teylan; Duane Beekly; George Thomas; Mark Bollenbeck; Sarah Monsell; Charles Mock; Xiao Hua Zhou; Nicole Thomas; Elizabeth Robichaud; Margaret Dean; Janene Hubbard; Mary Jacka; Kristen Schwabe-Fry; Joylee Wu; Creighton Phelps; John C Morris Journal: Alzheimer Dis Assoc Disord Date: 2018 Oct-Dec Impact factor: 2.703