Association of Statin Use with Dementia Risk Among Older Adults in Japan: A Nested Case-Control Study Using the LIFE Study.

Background: Previous studies have shown a possible association between statin use and a decreased risk of dementia, but the association has not been sufficiently established, especially in the super-aging society of Japan. Objective: This study aimed to determine the association between statin use and the risk of dementia among Japanese participants aged> =65 years old. Methods: Data from the Longevity Improvement and Fair Evidence (LIFE) Study were utilized, including medical and long-term care (LTC) claim data from 17 municipalities between April 2014 and December 2020. A nested case-control study was conducted with one case matched to five controls based on age, sex, municipality, and year of cohort entry. We used a conditional logistic regression model to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs). Results: This study included 57,302 cases and 283,525 controls, with 59.7% of the participants being woman. After adjusting for potential confounders, statin use was associated with a lower risk of dementia (OR, 0.70; 95% CI: 0.68-0.73) and Alzheimer's disease (OR: 0.66; 95% CI: 0.63-0.69). Compared with non-users, the ORs of dementia were as follows: 1.42 (1.34-1.50) for 1-30 total standardized daily dose (TSDD), 0.91 (0.85-0.98) for 31-90 TSDD, 0.63 (0.58-0.69) for 91-180 TSDD, and 0.33 (0.31-0.36) for >180 TSDD in dose-analysis. Conclusions: Statin use is associated with a reduced risk of dementia and Alzheimer's disease among older Japanese adults. A low cumulative statin dose is associated with an increased risk of dementia, whereas a high cumulative statin dose is a protective factor against dementia.

Statin use and risk of Parkinson's disease among older adults in Japan: a nested case-control study using the Longevity Improvement and Fair Evidence study.

The association between statin use and the risk of Parkinson's disease remains inconclusive, particularly in Japan's super-ageing society. This study aimed to investigate the potential association between statin use and the risk of Parkinson's disease among Japanese participants aged ≥65 years. We used data from the Longevity Improvement and Fair Evidence Study, which included medical and long-term care claim data from April 2014 to December 2020 across 17 municipalities. Using a nested case-control design, we matched one case to five controls based on age, sex, municipality and cohort entry year. A conditional logistic regression model was used to estimate the odds ratios with 95% confidence intervals. Among the 56 186 participants (9397 cases and 46 789 controls), 53.6% were women. The inverse association between statin use and Parkinson's disease risk was significant after adjusting for multiple variables (odds ratio: 0.61; 95% confidence interval: 0.56-0.66). Compared with non-users, the dose analysis revealed varying odds ratios: 1.30 (1.12-1.52) for 1-30 total standard daily doses, 0.77 (0.64-0.92) for 31-90 total standard daily doses, 0.62 (0.52-0.75) for 91-180 total standard daily doses and 0.30 (0.25-0.35) for >180 total standard daily doses. Statin use among older Japanese adults was associated with a decreased risk of Parkinson's disease. Notably, lower cumulative statin doses were associated with an elevated risk of Parkinson's disease, whereas higher cumulative doses exhibited protective effects against Parkinson's disease development.

Dietary Consumption of Antioxidant Vitamins in Relation to Prostate Cancer Risk in Japanese Men: The Japan Public Health Center-based Prospective Study.

BACKGROUND: Many epidemiological studies have investigated dietary intake of antioxidant vitamins in relation to prostate cancer risk in Western countries, but the results are inconsistent. However, few studies have reported this relationship in Asian countries. METHODS: We investigated the association between intake of vitamins, including lycopene, α-carotene, ß-carotene, vitamin C, vitamin E, with prostate cancer risk in the Japan Public Health Center-based Prospective (JPHC) study. 40,720 men without history of cancer finished the food frequency questionnaire (FFQ) and were included in the study. Hazard ratios (HRs) and 95% confidence intervals (CIs) of prostate cancer risk were calculated according to the quintiles of energy-adjusted intake of vitamins using Cox models. RESULTS: After an average of 15.2 years (617,599 person-years in total) of follow-up, 1,386 cases of prostate cancer were identified, including 944 localized cases and 340 advanced cases. No associations were observed in consumption of antioxidant vitamins, including α-carotene, ß-carotene, vitamin C, and vitamin E, and prostate cancer risk. Although higher lycopene intake was associated with increased risk of prostate cancer (highest vs lowest quintile, HR 1.24; 95% CI, 1.04-1.47; P for trend = 0.01), there was a null association of lycopene intake with risk of prostate cancer detected by subjective symptoms (HR 1.12; 95% CI, 0.79-1.58; P for trend = 0.11). CONCLUSION: Our study suggested no association between antioxidant intake of vitamins and prostate cancer risk.

Associations between dairy intake and mortality due to all-cause and cardiovascular disease: the Japan Public Health Center-based prospective study.

BACKGROUND: Some studies have investigated the relation between dairy products and mortality, but with inconsistent results. OBJECTIVE: We examined the association between the consumption of dairy products and the risk of all-cause, cancer-related, and cardiovascular disease (CVD)-related mortality. METHODS: From the Japan Public Health Center-based Prospective (JPHC) study, 43,117 males and 50,193 females with no history of cancer or CVD finished the food frequency questionnaire (FFQ) and were included in the study. Intake of dairy products was assessed using the FFQ and adjusted for total energy by using the residual method. We used multivariate Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for mortality risk in males and females. RESULTS: 14,211 deaths in males and 9547 deaths in females from all causes were identified during an average follow-up of 19.3 years. For males, total dairy consumption was nonlinearly and significantly associated with lower risk of mortality from all causes [the third quartile, HR = 0.87 (0.83, 0.91), the fourth quartile, HR = 0.89 (0.85, 0.94), P for nonlinearity < 0.001] and CVD [the third quartile, HR = 0.77 (0.70, 0.85), the fourth quartile, HR = 0.78 (0.70, 0.86), P for nonlinearity < 0.001]. Milk and fermented milk intake were inversely associated with all-cause and CVD-related mortality in males. Cheese consumption was inversely associated with CVD-related mortality among males. There was no association between total dairy intake and mortality risk among females. CONCLUSION: For Japanese people, consumption of dairy products was associated with a decreased risk of mortality from all-cause and cardiovascular diseases among males.