Smoking and Obesity as Risk Factors in Frontotemporal Dementia and Alzheimer's Disease: The HUNT Study.

Few studies have assessed smoking and obesity together as risk factors for frontotemporal dementia (FTD) and Alzheimer's disease (AD).To study smoking and obesity as risk factors for FTD and AD.Ninety patients with FTD and 654 patients with AD were compared with 116 cognitively healthy elderly individuals in a longitudinal design with 15-31 years between measurements of risk factors before the dementia diagnosis.

There were no associations between smoking and FTD (p = 0.218; odds ratio [OR]: 0.990; 95% confidence interval [CI]: 0.975-1.006). There were significant associations between obesity and FTD (p = 0.049; OR: 2.629; 95% CI: 1.003-6.894). There were significant associations between both smoking (p = 0.014; OR: 0.987; 95% CI: 0.977-0.997) and obesity (p = 0.015; OR: 2.679; 95% CI: 1.211-5.928) and AD.

Our findings suggest that obesity is a shared risk factor for FTD and AD, while smoking plays various roles as a risk factor for FTD and AD.