Association Between Tongue Pressure and Prevalence of Mild Cognitive Impairment in Japan.

OBJECTIVE: Although it has been suggested that a decline in oral function is one of the potential risk factors affecting mild cognitive impairment (MCI), evidence is insufficient to draw clear conclusions. This Japanese cross-sectional study examined the association between tongue pressure (TP) and MCI in middle-aged and older adults aged 36-84 years. METHODS: Study participants were 1019 (368 men and 651 women). TP was evaluated using a TP measurement device. The maximum value of three measurements was used for analysis. MCI was defined as being present if a participant had a Japanese version of the Montreal Cognitive Assessment score of <26. Adjustment was made for age, smoking status, alcohol consumption, leisure-time physical activity, body mass index, hypertension, dyslipidemia, diabetes mellitus, history of depression, number of teeth, employment, education, and household income. RESULTS: The prevalence of MCI was 45.3%. Among women, compared with the lowest tertile of TP, the second and highest tertiles were significantly associated with a lower prevalence of MCI with a clear dose-response relationship; the adjusted odds ratio (95% confidence intervals) in the second and highest tertiles of TP were 0.54 (0.36-0.83) and 0.55 (0.36-0.84), respectively (p for trend = 0.005). In contrast, no statistically significant association was observed between TP and the prevalence of MCI among men. CONCLUSIONS: Our findings suggest that higher TP might be inversely associated with the prevalence of MCI in middle-aged and older Japanese women.

Hearing Impairment and Prevalence of Mild Cognitive Impairment in Japan: Baseline Data From the Aidai Cohort Study in Yawatahama and Uchiko.

OBJECTIVES: Hearing impairment (HI) in midlife may increase the risk of dementia. However, epidemiological research on the association between HI and mild cognitive impairment (MCI) is very limited. DESIGN: The present cross-sectional study investigated the relationship between HI and MCI using baseline data from the Aidai Cohort Study. Study subjects were 995 Japanese adults aged 36 to 84 years. We used the audiometric definition of HI adopted by the World Health Organization, which identifies the speech-frequency pure-tone average hearing thresholds at 0.5, 1, 2, and 4 kHz tones. HI was defined as present when pure-tone average was >25 dB HL in the better hearing ear. MCI was defined as being present when a subject had a Japanese version of the Montreal Cognitive Assessment score of <26. Adjustment was made for age, sex, smoking status, alcohol consumption, leisure time physical activity, hypertension, dyslipidemia, diabetes mellitus, history of depression, body mass index, waist circumference, employment, education, and household income. RESULTS: Among the 995 study subjects, the prevalence values of HI and MCI were 24.3% and 44.5%, respectively. HI was independently positively associated with MCI: the multivariate-adjusted odds ratio (95% confidence interval) was 1.86 (1.32 to 2.62). HI was independently related to a higher prevalence of MCI in those aged 60 to 69 years and those aged 70 years or older: the multivariate-adjusted odds ratios (95% confidence intervals) were 1.64 (1.03 to 2.62) and 2.30 (1.04 to 5.27), respectively. CONCLUSIONS: HI may be associated with a higher prevalence of MCI.