Prevalence of Sinusitis Detected by Magnetic Resonance Imaging in Subjects with Dementia or Alzheimer's Disease.

BACKGROUND: It has been reported that periodontitis is associated with Alzheimer's disease. However, the association between paranasal sinusitis and Alzheimer's disease has not been studied, although olfactory dysfunction frequently precedes the progress of dementia or Alzheimer's disease. METHODS: We studied 783 patients (283 men, 500 women; mean age 77.0 ± 7.9 years) who visited the Center for Comprehensive Care and Research on Memory Disorders, National Center for Geriatrics and Gerontology, and 2139 control subjects who participated in a population-based study conducted by the National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA) in Japan. Sinusitis was evaluated using magnetic resonance imaging (MRI) according to the Lund-Mackay scoring system. A sinusitis score of ≥ 4 was classified as positive and a score of ≤ 3 was classified as negative. RESULTS: The prevalence of positive sinusitis was 6.3% in patients with a mini-mental state examination (MMSE) score of < 24 (n = 507), and 5.7% in patients with Alzheimer's disease (n = 280). The rate of positive sinusitis was7.2% in the control group. The prevalence of sinusitis was not significantly different between normal controls and patients with dementia or Alzheimer's disease after adjustments for age and sex. The rate of positive sinusitis was higher in male than in female subjects in both groups. CONCLUSION: The prevalence of sinusitis in patients with Alzheimer's disease or dementia was not higher than in the general population.

Association between polymorphisms in genes encoding methylenetetrahydrofolate reductase and the risk of Ménière's disease.

Folate metabolism is essential for cellular functioning. Despite extensive research on the roles of folate-metabolism-related gene polymorphisms in the pathophysiology of many diseases, such as cardiovascular disease, cancers, and sudden sensorineural hearing loss, little is known about their association with Ménière's disease (MD). The aim of this study was to investigate the effect of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) on the risk of MD in a Japanese population. We examined the C677T and A1298C (rs1801133 and rs1801131) polymorphisms in the MTHFR gene and compared them between 1946 adults (986 men and 960 women) participating in the National Institute for Longevity Sciences Longitudinal Study of Aging and 86 cases of MD. A multiple logistic regression was performed to obtain odds ratios (ORs) for the risk of MD regarding the MTHFR polymorphisms before (model 1) and after (model 2) adjustment for age and sex factors. The OR of MTHFR C677T for the risk of MD was 0.669 (95% confidence interval [CI], 0.479-0.934) in model 1 and 0.680 (95% CI, 0.484-0.954) in model 2. In contrast, the OR of MTHFR A1298C for the risk of MD was 1.503 (95% CI, 1.064-2.123) in model 1 and 1.505 (95% CI, 1.045-2.167) in model 2. Our results imply that the MTHFR C677T and A1298C polymorphisms are associated with the risk of MD.

The effects of aging on distortion-product otoacoustic emissions in adults with normal hearing.

OBJECTIVES: The focus of this study was to determine whether deterioration in cochlear function, as evaluated by distortion-product otoacoustic emission (DPOAE), exists before the elevation of audiometric thresholds occurs during the course of aging. In previous research, variability in normal audiometric thresholds likely contributed to the aging effect on OAE data. Therefore, in selecting subjects, we applied the stringent criterion in pure-tone thresholds (PTT) to limit dispersion among normal-hearing thresholds. DESIGN: We evaluated 331 subjects (136 men and 195 women) of a population-based sample of 2259 adults aged 40 to 82 yr who took part in the Longitudinal Study of Aging. We chose subjects according to the audiometric criterion that thresholds at any of five frequencies, namely 500, 1000, 2000, 4000, and 8000 Hz, did not exceed 15 dB HL. The mean age of our subjects was 48.3 +/- 7.4 yr (range, 41 to 72 yr) in men and 49.6 +/- 7.6 yr (range, 41 to 80 yr) in women. In a univariate analysis, analysis of variance was performed on DPOAE amplitudes and noise estimates at 22 test frequencies, as well as on the PTT. Age groups (40s, 50s, 60s, and above) were considered separately for men and women, without adjustment for any confounding variables. In a multivariate approach, general linear model analyses were performed to focus attention on the impact of age as a continuous variable, and on the influence of PTT on DPOAE levels. The multivariate analysis was conducted separately for men and women. DPOAE amplitudes at nine test frequencies were set as objective variables. Age (continuous variable), PTT at the corresponding test frequency, and interaction between age and PTT at the corresponding test frequency were evaluated as explanatory variables with adjustment for static admittance, history of ear disease (yes = 1), and history of occupational noise exposure (yes = 1). RESULTS: Of the 22 test frequencies, we found a statistically significant difference in DPOAE amplitudes among age groups at four test frequencies in men, ranging from 4761 to 6165 Hz, and at all but the 3088 Hz test frequency in women. Despite the stringent audiometric inclusion criterion, statistically significant differences in the mean PTT among the age groups were observed at 4000 Hz in men and at all five tested frequencies in women. Multivariate analyses demonstrated a significant negative effect of age on DPOAE levels at 1086 Hz f2 frequency in men and at the 1184, 2002, 2185, 4004, and 4358 Hz f2 frequencies in women. Regarding PTT, neither main nor interactive effect on DPOAE amplitude was statistically significant at any of nine test frequencies. The goodness-of-fit of the model, in terms of R2, ranged from 0.05 to 0.11 in men and from 0.11 to 0.18 in women. CONCLUSIONS: The present analyses substantiated the hypothesis DPOAEs deteriorate with age independently of hearing sensitivity. The aging effect on DPOAE measures was observed more in women than in men. We conclude that DPOAE measurements in audiometrical normal-hearing elderly may provide early indications of cochlear damage because of aging.