The Association Between Hyperhidrosis and Dementia: A Community-Based Research

Background: Dementia and hyperhidrosis (HH) are common in the elderly while there is little research to investigate the association between them. Objective: To clarify a possible association between HH and dementia in population of adults >= 65 years old in China. Methods: A cross-sectional survey for elderly adults >= 65 years old was conducted from April to December 2019. A total of 5,958 participants were analyzed after two phases investigation. Goodness-of-fit tests (Pearson and deviance) were used to estimate the dispersion parameter and examine the adequacy of the models. Logistic and linear regression analyses were used to evaluate the association between HH and dementia. Results: The overall prevalence of all-cause dementia was 10.17%, that of dementia with Lewy bodies (DLB) was 1.41%, and HH was 14.97%. Prevalence rates of HH were higher in participants with dementia and DLB. There was a significant positive relationship between HH duration and MMSE score (r = 0.207, p < 0.001, Durbin-Watson test = 1.806). Participants with HH were 1.275 (95% CI: 1.015-1.601, p = 0.037) times to have dementia, and 3.616 (95% CI: 2.267-5.767, p < 0.001) times to suffer from DLB than those without HH. Pearson and deviance chi square tests did not indicate overdispersion (p > 0.05 in the logistic regression models). Conclusion: HH was common in the Chinese population >= 65 years old. It can increase the risk of dementia, particularly in DLB, in the elderly. It is important to improve the awareness of HH among dermatologists and neurologists.