Daytime napping and the risk of gastric cancer: the JACC Study.

BACKGROUND: Gastric cancer is a major cause of morbidity and mortality in Japan and worldwide. Emerging literature has suggested unfavorable health outcomes associated with daytime napping. Herein, we aimed to investigate the association between daytime napping and the risk of gastric cancer among Japanese people. METHODS: This prospective cohort study included 49,037 participants, aged 40-79 years, from the Japan Collaborative Cohort Study (JACC Study). Participants with positive cancer history and those who reported night or rotational shift work were excluded. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident gastric cancer among daytime nappers. RESULTS: Within 650,040 person-years (median = 13.7 years) of follow-up, 1,164 participants developed gastric cancer. Daytime napping was associated with the increased risk of gastric cancer in the multivariable-adjusted model: HR (95% CI) = 1.14 (1.01, 1.29). The excess risk did not significantly differ across sexes, age groups (<65 and ≥65 years), and employment status (employed and unemployed) (p-interactions > 0.40). However, sleep duration modified this effect: HRs (95% CIs) = 1.66 (1.23, 2.23) in sleep duration ≤6 h/night versus 1.06 (0.93, 1.21) in sleep duration >6 h/night (p-interaction = 0.006). CONCLUSION: Daytime napping was associated with increased gastric cancer risk, especially among those who reported short sleep duration.

Fatty Liver Index as a proxy for non-alcoholic fatty liver disease and the risk of stroke and coronary heart disease: The Suita Study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in developed countries, but its role in predicting cardiovascular disease (CVD) needs further investigation. Herein, we studied the association between NAFLD and the risk of CVD, stroke, and coronary heart disease (CHD) among Japanese people. METHODS: This prospective cohort study analyzed data from 2,517 men and 3,958 women, aged 30-84 years, who were registered in the Suita Study. NAFLD was defined as Fatty Liver Index (FLI) ≥ 60. Cox proportional hazard models were applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident CVD, stroke, and CHD events by baseline FLI. The results were adjusted for age, smoking, alcohol consumption, hypertension, diabetes, lipid profile, chronic kidney disease, and cardiac murmur or valvular diseases. RESULTS: Within 16.6 years of median follow-up, 590 participants developed CVD (346 stroke events and 244 CHD events). Women with NAFLD (FLI ≥ 60) showed a higher risk of CVD and stroke: HRs (95% CIs) = 1.69 (1.16, 2.46) and 2.06 (1.31, 3.24), respectively. Besides, women in the fourth and fifth (highest) FLI quintiles showed a higher risk of CVD and stroke than those in the third (middle) quintile: HRs (95% CIs) = 1.60 (1.08, 2.36) and 1.67 (1.13, 2.45) for CVD and 1.73 (1.07, 2.79) and 1.90 (1.18, 3.05) for stroke, respectively. No corresponding associations were detected in men. NAFLD was not associated with CHD risk in either sex. CONCLUSIONS: NAFLD, diagnosed by FLI, was associated with a higher risk of CVD and stroke in Japanese women. From a preventive perspective, women with NAFLD should be targeted for CVD screenings and interventions.

The association between stair climbing and modifiable cardiovascular disease risk factors: the Suita Study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardiovascular benefits. This study aimed to investigate the association between stair climbing and numerous modifiable cardiovascular disease (CVD) risk factors. METHODS: In this cross-sectional study, we used data from 7282 Japanese people (30-84 years) residing in Suita City, Osaka. CVD risk factors and stair climbing frequency were assessed during the Suita Study health examination. Logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (95% CIs) for CVD risk factors across stair climbing frequencies. RESULTS: After adjustment for age, sex, lifestyle, and medical conditions, stair climbing >60% of the time, compared to <20% of the time, was inversely associated with obesity, smoking, physical inactivity, and stress: ORs (95% CIs) = 0.63 (0.53, 0.75), 0.81 (0.69, 0.96), 0.48 (0.41, 0.55), and 0.67 (0.58, 0.78), respectively (p-trends < 0.05). CONCLUSION: Stair climbing was inversely associated with obesity, smoking, physical inactivity, and stress; suggesting a potential role for cardiovascular disease prevention.

Liver enzymes and the risk of stroke among the general Japanese population: a prospective cohort study.

BACKGROUND: Stroke is a major cause of morbidity and mortality. Liver enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transpeptidase (GGT), are markers of liver diseases with potential cardiovascular implications. OBJECTIVE: This study aimed to investigate the prospective association between liver enzymes and stroke risk. METHODS: We analyzed data from 3,379 men and 4,007 women without cardiovascular disease and registered in the Suita Study; a Japanese population-based prospective cohort study. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) of stroke risk were estimated per quintiles of ALT, AST, and GGT in men and women. RESULTS: Within a median follow-up period of 16.7 years, 438 incident stroke events were diagnosed. In men, compared to the second quintiles, the fifth (highest) quintiles of liver enzymes showed increased stroke risks: HRs (95% CIs) = 2.07 (1.35, 3.18) in ALT, 1.66 (1.10, 2.53) in AST, and 1.76 (1.11, 2.81) in GGT. The associations did not change with cerebral infarction risk: HRs (95% CIs) = 2.09 (1.24, 3.50) in ALT, 1.84 (1.11, 3.06) in AST, and 1.74 (1.00, 3.04) in GGT, respectively. The lowest ALT, AST, and GGT quintiles tended to show increased stroke and cerebral infarction risks, yet these associations were statistically insignificant. No such associations were shown in women. CONCLUSION: Elevated ALT, AST, and GGT levels were associated with increased stroke and cerebral infarction risks among Japanese men.

Fatty Liver Index and the Risk of Atrial Fibrillation in a General Japanese Population　- The Suita Study.

BACKGROUND: Atrial fibrillation (AF) is the most diagnosed arrhythmia in clinical settings. The fatty liver index (FLI) is a marker of liver steatosis with potential cardiovascular implications. This study investigated whether FLI could predict the risk of AF.Methods and Results: We used data from the Suita Study, a Japanese population-based prospective cohort study. A total of 2,346 men and 3,543 women, aged 30-84 years, without prevalent AF were included and followed up. The diagnosis of AF was established during follow-up using electrocardiograms, hospital records, and death certificates. FLI was assessed during a baseline health checkup. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for incident AF per FLI quintile and log-transformed FLI. Within a median 14.5 years of follow-up, 142 men and 105 women developed AF. Compared with women in the third (middle) FLI quintile, women in the first (lowest), fourth, and fifth (highest) quintiles showed a higher risk of AF, with multivariable-adjusted HRs of 2.37 (95% CI 1.06-5.31), 2.60 (95% CI 1.30-5.17), and 2.04 (95% CI 1.00-4.18), respectively. No corresponding associations were observed in men. The change in log-transformed FLI was not associated with the risk of AF in either sex. CONCLUSIONS: A U-shaped association between FLI and AF risk was detected in Japanese women. FLI could be a screening tool to detect women at high risk of developing AF.

Vitamin K Intake and Risk of Lung Cancer: The Japan Collaborative Cohort Study.

BACKGROUND: Limited reports from prospective human studies investigated the possible role of vitamin K in the development of lung cancer although vitamin K's anticarcinogenic activities were verified from several in vitro and in vivo studies. We investigated the associations between total vitamin K intake from food and the development of lung cancer based on this large prospective cohort study. METHODS: A validated food frequency questionnaire was used to examine vitamin K intake among 42,166 (16,341 men and 25,825 women) at the Japan Collaborative Cohort Study's baseline (1988-1990). Hazard ratios (HRs) and 95% confidence intervals (CIs) of incident lung cancer were calculated using the Cox proportional hazard regression method based on vitamin K consumption quartiles. RESULTS: 430 cases (308 males and 122 women) of lung cancer were documented during a total of 564,127 person-years of follow-up (median follow-up, 14.6 years). Vitamin K consumption was shown to be inversely related to lung cancer risk; the multivariable hazard ratio [HR] for the highest versus lowest quartiles was 0.67 (95% confidence interval [CI], 0.46-0.96; P for trend = 0.010). This relationship appears to be stronger in males (HR 0.62; 95% CI, 0.40-0.96; P for trend = 0.016) than in females (HR 0.82; 95% CI, 0.42-1.61; P for trend = 0.39) (P for interaction = 0.012), and in ever smokers (HR 0.57; 95% CI, 0.36-0.91; P for trend = 0.006) than in never smokers (HR 0.79; 95% CI, 0.40-1.55; P for trend = 0.37) (P for interaction = 0.30). The individuals' age, body mass index, or alcohol consumption status had no effect on the observed connection. CONCLUSION: Vitamin K consumption reduces the risk of lung cancer. More research is needed to clarify the molecular processes behind this connection.

Daytime napping and risk of liver cancer: A large population-based prospective cohort study.

INTRODUCTION AND OBJECTIVES: Liver cancer is a major cause of morbidity and mortality in Japan and worldwide. Daytime napping is a common behavior, especially among older adults, that was related in previous research to unfavorable health conditions. Herein, we investigated the association between daytime napping and liver cancer risk. MATERIALS AND METHODS: In this prospective cohort study, data from 51,185 participants aged 40-79 years and registered in the Japan Collaborative Cohort Study (JACC Study) were analyzed. Incident cases of liver cancer were diagnosed using cancer registries, hospital records, and death certificates. Daytime napping was assessed using the JACC baseline self-administered questionnaire. We used the Cox regression to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of incident liver cancer among participants in the age categories of the 40s, 50s, 60s, and 70s who reported daytime napping compared with their counterparts who did not. RESULTS: Within 669,734 person-years of follow-up, 341 participants developed liver cancer. Daytime napping was associated with a higher risk of liver cancer among participants who were in their 60s and 70s of age after adjusting for sex: HRs (95% CIs) 1.88 (1.35-2.61) and 1.96 (1.18-3.26), lifestyle and medical history: 1.76 (1.27-2.47) and 1.82 (1.07-3.09), and history of liver diseases: 1.66 (1.18-2.34) and 1.72 (1.01-2.94), respectively. No associations were detected among participants from the 40s and 50s age groups. CONCLUSIONS: Daytime napping was associated with a higher risk of liver cancer among older adults.

Effect of different sintering protocols on the fracture strength of 3-unit monolithic gradient zirconia fixed partial dentures: An in vitro study.

STATEMENT OF PROBLEM: Strength-gradient zirconia combining 3 zirconia formulations with different flexural strengths has been reported to have outstanding mechanical properties. However, data concerning the effect of different sintering protocols on the fracture strength of 3-unit monolithic gradient zirconia fixed partial dentures (FPDs) are sparse. PURPOSE: The purpose of this in vitro study was to test the effect of different sintering protocols on the fracture strength of 3-unit monolithic gradient zirconia FPDs. MATERIAL AND METHODS: Two custom-made stainless-steel master dies were designed to replicate a mandibular right second premolar and second molar prepared to receive a 3-unit monolithic zirconia FPD. Thirty monolithic zirconia FPDs were milled from gradient zirconia blanks and allocated to 3 groups (n=10) according to the sintering protocols: high-speed sintering, speed sintering, and conventional sintering. The FPDs were cemented onto the corresponding dies with traditional glass ionomer cement. All FPDs were cyclic loaded (600 000 cycles/49 N/1.7 Hz) in a mastication simulator. Fracture load measurements for each FPD were determined by using a universal testing machine. Scanning electron microscopy (SEM) at ×80 magnification was used to examine a fractured FPD from each group. A representative specimen from each group was examined with SEM at ×30 000 magnification to determine the grain size. One-way ANOVA, pair-wise Tukey honestly significant difference (HSD), and Pearson correlation tests were used for statistical analysis of the data (α=.05). RESULTS: The high-speed sintered FPDs recorded the highest statistically significant fracture load mean ±standard deviation value (2526 ±300 N), followed by the speed sintered FPDs (2136 ±127 N), while the lowest statistically significant fracture load mean value was recorded with the conventionally sintered FPDs (1361 ±181 N) (P<.001). In addition, the mean ±standard deviation grain size values were 488 ±272 nm for the high-speed sintered specimen, 578 ±409 nm for the speed sintered specimen, and 832 ±551 nm for the conventionally sintered specimen (P<.001). A significant negative correlation was found between fracture strength and grain size among the 3 groups. CONCLUSIONS: The fracture strength of 3-unit monolithic gradient zirconia FPDs sintered by using a high-speed protocol was significantly higher than that of speed and conventionally sintered FPDs (P<.001). The high-speed sintering protocol reduced the mean grain size of gradient zirconia FPDs compared with that of both speed and conventional sintering protocols.

Stress distribution and fracture resistance of green reprocessed polyetheretherketone (PEEK) single implant crown restorations compared to unreprocessed PEEK and Zirconia: an in-vitro study.

BACKGROUND: It is unclear which crown materials are optimum to disperse the generated stresses around dental implants. The objective of this study is to assess stress distribution and fracture resistance of green reprocessed Polyetheretherketone (PEEK) in comparison to un-reprocessed PEEK and zirconia single implant crown restorations. METHODS: Twenty crowns (n = 20) were obtained, five from zirconia and fifteen from pressed PEEK that were subdivided into 3 groups of five specimens each (n = 5) according to weight% of reprocessed material used. A 100% new PEEK was used for the first group, 50% new and 50% reprocessed PEEK were used for the second group, and a 100% reprocessed PEEK was used for the third group. Epoxy resin model with dental implant in the second mandibular premolar was constructed with strain gauges located mesially and distally to the implant to record strain while a load of 100 N was applied with 0.5 mm/min then specimens of all groups were vertically loaded till failure in a universal testing machine at cross head speed 1 mm/min. Data was statistically analyzed by using One-way Analysis of Variance (ANOVA) followed by Post-hoc test when ANOVA test is significant. RESULTS: No significant difference between strain values of tested groups (p = 0.174) was noticed. However, a significant difference between fracture resistance values was noticed where the zirconia group recorded a significantly higher value (p < 0.001). CONCLUSIONS: Implant restorative materials with different moduli of elasticity have similar effects regarding stresses distributed through dental implant and their surrounding bone. Reprocessed PEEK implant restorations transmit similar stresses to dental implant and surrounding bone as non-reprocessed PEEK and zirconia restorations. Zirconia failed at higher load values than all tested PEEK restorations but all can be safely used in the posterior area as crown restorations for single implants. CLINICAL RELEVANCE: Applying "green dentistry" principles may extend to include reprocessing of pressed PEEK restorative materials without affecting the material's shock absorption properties.

Stair climbing and the incidence of atherosclerotic cardiovascular disease: a population-based prospective cohort study.

BACKGROUND: Stair climbing is a readily available form of physical activity with potential cardioprotective merits. Herein, we investigated the association between stair climbing and atherosclerotic cardiovascular disease (ASCVD) incidence among Japanese people. METHODS: This prospective cohort study used data from 7,282 participants, aged 30-84 years, registered in the Suita Study and free from stroke and ischemic heart disease (IHD). Standard approaches were used to detect incident ASCVD events, including cerebral infarction and IHD, during follow-up. Stair climbing was assessed using a baseline questionnaire. We applied the Cox regression to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of incident ASCVD for climbing stairs in 20-39%, 40-59%, and ≥60% compared to <20% of the time. We adjusted the regression models for age, sex, body mass index, smoking, alcohol consumption, physical activity, hypertension, diabetes, atrial fibrillation, lipid profile, chronic kidney disease, and history of cardiac murmur or valvular diseases. RESULTS: A total of 536 new ASCVD events were detected within a median follow-up period of 16.6 years. In the age- and sex-adjusted model, stair climbing 20-39%, 40-59%, and ≥60% of the time was associated with lower ASCVD incidence: HRs (95% CIs) = 0.72 (0.56, 0.92), 0.86 (0.68, 1.08), and 0.78 (0.61, 0.99), respectively (p-trend = 0.020). The corresponding associations were attenuated after adjusting for lifestyle and clinical factors: HRs (95% CIs) = 0.74 (0.58, 0.95), 0.90 (0.71, 1.13), and 0.89 (0.69, 1.13), respectively (p-trend = 0.152). CONCLUSION: Frequent stair climbing was associated with lower ASCVD incidence; however, this association was partly explained by lifestyle and clinical factors of participants.

Life satisfaction and the risk of atherosclerotic cardiovascular disease in the general Japanese population: the Suita Study.

BACKGROUND: Atherosclerotic cardiovascular disease (ASCVD) is a major cause of morbidity and mortality. Life satisfaction is a measure of mental health with a potential cardioprotective role. This study aimed to investigate the association between life satisfaction and ASCVD risk in the general Japanese population. METHOD: We used data from 6,877 people (30-84 years) registered in the Suita Study, a Japanese population-based prospective cohort study. All participants were free from stroke and coronary heart disease (CHD) at baseline. Then, participants were followed up for incident ASCVD, including cerebral infarction and CHD. Cox proportional hazards models were used to calculate the hazard ratio (HR) and 95% confidence interval (95% CI) of incident ASCVD according to life satisfaction. RESULTS: Within 102,545 person-years (median follow-up = 16.6 years), 482 incident ASCVD events were identified. In the age- and sex-adjusted model, being very satisfied, rather satisfied, or not sure, compared to being dissatisfied with life, showed a lower risk of ASCVD: HR (95% CI) = 0.55 (0.41, 0.74), 0.67 (0.50, 0.89), and 0.57 (0.36, 0.88), respectively (p-trend < 0.001). The associations remained consistent after adjusting for stress and unfortunate events: HR (95% CI) = 0.57 (0.42, 0.77), 0.68 (0.50, 0.91), and 0.54 (0.35, 0.84), respectively (p-trend < 0.001). The results did not vary between cerebral infarction and CHD: HR (95% CI) for being very satisfied with life = 0.58 (0.37, 0.91) and 0.55 (0.36, 0.84), respectively. CONCLUSION: Life satisfaction was inversely associated with the risk of ASCVD in the investigated general Japanese population.

Alcohol consumption and the risk of heart failure: the Suita Study and meta-analysis of prospective cohort studies.

BACKGROUND: Alcohol consumption is a modifiable lifestyle, but its role in heart failure (HF) development is controversial. Herein, we investigated the prospective association between alcohol consumption and HF risk. METHODS: A total of 2,712 participants (1,149 men and 1,563 women) from the Suita Study were followed up every two years. Cox regression was applied to calculate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of HF risk for heavy drinking (≥46 g/day in men or ≥23 g/day in women) and never drinking compared to light drinking (<23 g/day in men or <11.5 g/day in women). Then, we combined the results of the Suita Study with those from other eligible prospective cohort studies in a meta-analysis using the random-effects model. RESULTS: In the Suita Study, within a median follow-up period of 8 years, 319 HF cases (162 in men and 157 in women) were detected. In men, but not women, never and heavy drinking carried a higher risk of HF than light drinking: HRs (95% CIs) = 1.65 (1.00, 2.73) and 2.14 (1.26, 3.66), respectively. Alike, the meta-analysis showed a higher risk of HF among heavy drinkers: HR (95% CI) = 1.37 (1.15, 1.62) and abstainers: HR (95% CI) = 1.18 (1.02, 1.37). CONCLUSION: We indicated a J-shaped association between alcohol consumption and HF risk among Japanese men. The results of the meta-analysis came in line with the Suita Study. Heavy-drinking men should be targeted for lifestyle modification interventions.

Development of new scores for atherosclerotic cardiovascular disease using specific medical examination items: the Suita Study.

BACKGROUND: We previously developed risk models predicting stroke, coronary heart disease (CHD), and cardiovascular disease (CVD) among Japanese people from the Suita Study. Yet, applying these models at the national level was challenging because some of the included risk factors differed from those collected in the Japanese governmental health check-ups, such as Tokutei-Kenshin. We, therefore, conducted this study to develop new risk models for stroke, CHD, and atherosclerotic CVD (ASCVD), based on data from the Suita Study. The new models used traditional cardiovascular risk factors similar to those in the Japanese governmental health check-ups. METHODS: We included 7,413 participants, aged 30-84 years, initially free from stroke and CHD. All participants received baseline health examinations, including a questionnaire assessing their lifestyle and medical history, medical examination, and blood and urine analysis. The risk factors of stroke, CHD, and ASCVD (cerebral infarction or CHD) were determined using the multivariable-adjusted Cox regression. The models' performance was assessed using the C-statistics for discrimination and the Hosmer-Lemeshow for calibration. We also developed three simple scores (zero to 100) that could predict the 10-year incidence of stroke, CHD, and ASCVD. RESULTS: Within 110,428 person-years (median follow-up = 16.6 years), 410 stroke events, 288 CHD events, and 527 ASCVD events were diagnosed. Age, smoking, hypertension, and diabetes were associated with stroke, CHD, and ASCVD risk. Men and those with decreased high-density lipoproteins or increased low-density lipoproteins showed a higher risk of CHD and ASCVD. Urinary proteins were associated with an increased risk of stroke and ASCVD. The C-statistic values of the risk models were >0.750 and the p-values of goodness-of-fit were >0.30. The 10-year incidence of stroke, CVD, and ASCVD events was 3.8%, 3.5%, and 5.7% for scores 45-54, 10.3%, 11.8%, and 19.6% for scores 65-74, and 27.7%, 23.5%, and 60.5% for scores ≥85, respectively. CONCLUSIONS: We developed new Suita risk models for stroke, CHD, and ASCVD using variables similar to those in the Japanese governmental health check-ups. We also developed new risk scores to predict incident stroke, CHD, and ASCVD within 10 years.

Developing a Stroke Risk Prediction Model Using Cardiovascular Risk Factors: The Suita Study.

INTRODUCTION: Stroke remains a major cause of death and disability in Japan and worldwide. Detecting individuals at high risk for stroke to apply preventive approaches is recommended. This study aimed to develop a stroke risk prediction model among urban Japanese using cardiovascular risk factors. METHODS: We followed 6,641 participants aged 30-79 years with neither a history of stroke nor coronary heart disease. The Cox proportional hazard model estimated the risk of stroke incidence adjusted for potential confounders at the baseline survey. The model's performance was assessed using the receiver operating characteristic curve and the Hosmer-Lemeshow statistics. The internal validity of the risk model was tested using derivation and validation samples. Regression coefficients were used for score calculation. RESULTS: During a median follow-up duration of 17.1 years, 372 participants developed stroke. A risk model including older age, current smoking, increased blood pressure, impaired fasting blood glucose and diabetes, chronic kidney disease, and atrial fibrillation predicted stroke incidence with an area under the curve = 0.76 and p value of the goodness of fit = 0.21. This risk model was shown to be internally valid (p value of the goodness of fit in the validation sample = 0.64). On a risk score from 0 to 26, the incidence of stroke for the categories 0-5, 6-7, 8-9, 10-11, 12-13, 14-15, and 16-26 was 1.1%, 2.1%, 5.4%, 8.2%, 9.0%, 13.5%, and 18.6%, respectively. CONCLUSION: We developed a new stroke risk model for the urban general population in Japan. Further research to determine the clinical practicality of this model is required.

Dairy intake and the risk of pancreatic cancer: the Japan Collaborative Cohort Study (JACC Study) and meta-analysis of prospective cohort studies.

Dairy product intake was suggested to reduce the risk of gastrointestinal cancers. This study investigated the association between dairy product intake and the risk of pancreatic cancer (PAC) using a prospective cohort study and meta-analysis of prospective cohort studies. First, we included 59 774 people aged 40-79 years from the Japan Collaborative Cohort Study (JACC Study). The Cox regression was used to compute the hazard ratios (HR) and 95 % CI of incident PAC for individuals who reported the highest intakes of milk, cheese and yogurt compared with not consuming the corresponding dairy products. Then, we combined our results with those from other four prospective cohort studies that were eligible after searching several databases, in a meta-analysis, using the fixed-effects model before evaluating publication bias and heterogeneity across studies. In the JACC Study, the highest v. no intakes of milk, cheese and yogurt were not associated with the reduced risk of PAC after a median follow-up of 13·4 years: HR (95 % CI) = 0·93 (0·64, 1·33), 0·91 (0·51, 1·62) and 0·68 (0·38, 1·21), respectively. The results did not significantly change in the meta-analysis: 0·95 (0·82, 1·11) for milk, 1·16 (0·87, 1·55) for cheese and 0·91 (0·79, 1·05) for yogurt. The meta-analysis showed no signs of publication bias or heterogeneity across studies. To conclude, consumption of milk, cheese and yogurt was not associated with the risk of PAC either in the JACC Study or the meta-analysis.

Playing a musical instrument and the risk of dementia among older adults: a systematic review and meta-analysis of prospective cohort studies.

BACKGROUND: Engaging in leisure activities was suggested to protect older adults from dementia. However, the association between playing a musical instrument and the risk of dementia is not well-established. This study aimed to investigate this association in older adults using a systematic review and meta-analysis of prospective cohort studies. METHODS: Pooled hazard ratio (HR) and 95% confidence interval (CI) of having dementia for older adults playing a musical instrument were calculated using the random-effects model. We performed the I2 statistic to detect heterogeneity across studies and the test for funnel plot asymmetry to assess publication bias. The risk of bias assessment was conducted using the modified Newcastle-Ottawa Scale. RESULTS: A total of three prospective cohort studies were found eligible: two from the U.S. and one from Japan. Playing a musical instrument, in the meta-analysis, was significantly associated with a decreased risk of dementia (HR = 0.64; 95% CI: 0.41, 0.98) among older adults. No signs of significant heterogeneity across studies (I2 = 23.3% and p-heterogeneity = 0.27) or publication bias (z= -1.3 and p-publication bias = 0.18) were identified. CONCLUSION: Playing a musical instrument was associated with a decreased risk of dementia among older adults. Older adults should be encouraged to engage in leisure activities, especially playing musical instruments.

Association Between White Blood Cell Count and Atrial Fibrillation Risk　- A Population-Based Prospective Cohort Study.

BACKGROUND: The incidence and prevalence of atrial fibrillation (AF) are increasing. The white blood cell (WBC) count is an indicator of systemic inflammation and is related to increased cardiovascular disease risk. Using data from the Suita Study, we investigated the association between WBC count and AF risk in the general Japanese population.Methods and Results: This prospective cohort study included 6,884 people, aged 30-84 years, with no baseline AF. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for AF incidence by WBC count quintile. Within a median follow-up period of 14.6 years, 312 AF cases were diagnosed. Compared with the lowest WBC count quintile, the highest quintile was associated with an increased AF risk (HR 1.57; 95% CI 1.07-2.29). The association was more pronounced among women than men (HR 2.16 [95% CI 1.10-4.26] and 1.55 [95% CI 0.99-2.44], respectively; P interaction=0.07), and among current than non-smokers (HR 4.66 [95% CI 1.89-11.50] and 1.61 [95% CI 1.01-2.57], respectively; P interaction=0.20). For each 1.0×109-cells/L increment in WBC count, AF risk increased by 9% in men (9% in non-smokers, 10% in current smokers) and 20% in women (13% in non-smokers, 32% in current smokers). CONCLUSIONS: A higher WBC count was positively associated with an elevated AF risk in the general Japanese population, especially in women who smoked.

QRS transitional zone rotations and the risk of atrial fibrillation: the Suita Study.

ECG screening can detect people at risk of developing atrial fibrillation (AF). Recent literature indicated that QRS transitional zone rotations could predict several cardiovascular events. Herein, we investigated the association between QRS transitional zone rotations and the future risk of AF. This prospective cohort study included 6794 participants (3178 men and 3616 women), aged 30-84 years, from the urban Japanese city of Suita. QRS transitional zone rotations were diagnosed by ECG during baseline, while AF was diagnosed by ECG, hospital records, and checkups during follow-up. The Cox regression was used to compute the sex-specified hazard ratios (HRs) and 95% confidence intervals (CIs) of incident AF for participants with counterclockwise and clockwise QRS transitional zone rotations compared to those with normal rotation. Within a median follow-up period of 14.6 years, 311 participants (206 men and 105 women) developed AF. Counterclockwise rotation was associated with the reduced risk of AF among men, but not women, in the age-adjusted model: HR (95% CI) = 0.66 (0.44, 0.98) and the multivariable-adjusted model: HR (95% CI) = 0.65 (0.43, 0.97). Clockwise rotation was not associated with AF risk in either sex. To the best of our knowledge, this is the first study to indicate that counterclockwise rotation could be associated with the reduced risk of AF in men. More studies are needed to confirm our findings and elucidate possible mechanisms.

Chronic exposure to nitrate in drinking water and the risk of bladder cancer: a meta-analysis of epidemiological evidence.

OBJECTIVE: This study aimed to assess the association between chronic exposure to nitrate in drinking water and the risk of bladder cancer. STUDY DESIGN: Meta-analysis. METHODS: After a systematic retrieval of eligible epidemiological studies, pooled odds ratios (ORs) with 95% confidence intervals (CIs) of bladder cancer for people in the highest vs the lowest categories of nitrate exposure were calculated using the fixed- or random-effects model. We conducted two separate meta-analyses, one considering nitrate exposure as nitrate concentration in drinking water and the other one as daily nitrate intake from drinking water. RESULTS: A total of five studies (three case-control and two cohort studies) were included. The pooled OR (95% CI) of bladder cancer for the highest vs the lowest category of nitrate concentration in drinking water was 0.98 (0.60, 1.57), and daily nitrate intake from drinking water was 1.00 (0.69, 1.45). Both meta-analyses showed high heterogeneity across studies (I2 = 80.8% and 65.0%, respectively). Removing studies with the high risk of bias increased the risk and reduced the heterogeneity: [(nitrate concentration in drinking water: 1.36 (1.03, 1.79), I2 = 0.0%) and (daily nitrate intake from drinking water: 1.14 (0.90, 1.46), I2 = 8.4%)]. CONCLUSION: The current epidemiological evidence failed to establish a conclusive relationship between chronic exposure to nitrate in drinking water and the risk of bladder cancer. While no association and high heterogeneity across studies were detected in the two meta-analyses, removing studies with the high risk of bias increased the risk and dissolved the heterogeneity.

The effect of mechanical and chemo-mechanical temporary cement cleaning methods on shear bond strength with self-adhesive resin cement (an in-vitro study).

BACKGROUND: Adhesive tooth-colored restorations are strongly dependent on the substrate surface cleanliness to allow intimate contact between resin cement and dentin surface, so several methods were adopted for the total cleaning of temporary cement residues. This study aimed to assess the effect of mechanical and chemo-mechanical cleaning methods of temporary cement on the immediate shear bond strength of self-adhesive resin cement to dentin surface. METHODS: Forty freshly extracted lower first premolars were cut to expose a flat dentin surface. Discs of temporary crown composite resin material were constructed and cemented to the flat dentin surface using resin-based and non-eugenol temporary cement then stored at room temperature in distilled water. Dividing of samples into two groups according to the method of temporary cement cleaning. Group I (n = 20) mechanical cleaning using the rotary instrument, and group II (n = 20) chemo-mechanical cleaning using chlorhexidine-containing scrub. CAD/CAM reinforced Composite discs were bonded to the dentin surface using self-adhesive composite resin cement, then measurement of shear bond strength was done using a universal testing machine. Further analysis of failure mode after debonding was performed by Scanning electron microscope. RESULTS: No statistically significant difference was found between the mean shear bond strength of the two cleaning methods (P-value = 0.636). Regardless of the cleaning method, the group cemented with resin-based temporary cement showed statistically significantly higher mean shear bond strength than non-eugenol temporary cement (P-value = 0.048). CONCLUSION: Both cleaning methods (mechanical and chemo-mechanical) applied in this study were effective in cleaning temporary cement remnants from the dentin substrate surface with statistically significant differences between results of shear bond strength with significantly higher values recorded with resin-based temporary cement.