Physical Activity and Bladder Cancer Risk: Findings of the Japan Collaborative Cohort Study

Hang An,Keyang Liu,Kokoro Shirai,Ryo Kawasaki,Akiko Tamakoshi,Hiroyasu Iso 대한암학회 2024 Cancer Research and Treatment Vol.56 No.2

Purpose The association of physical activity with the risk of bladder cancer remains inconsistent among Asian populations. We aimed to examine the association in a large Japanese cohort.Materials and Methods In a population-based prospective cohort study, a total of 50,374 Japanese adults aged 40-79 years without a history of cancer or cardiovascular disease who had information on physical activity from self-administrated questionnaires were used for analysis. We performed Cox proportional hazard models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident bladder cancer after adjusting for several potential confounders.Results During the median 17.5 years of follow-up, 153 incident bladder cancers (116 men and 37 women) were identified. After the multivariable adjustment, HRs (95% CI) of bladder cancer concerning those with recreational sports participation of 1-2 hr/wk, 3-4 hr/wk, and 5 hr/wk and more were 0.67 (0.38-1.20), 0.79 (0.36-1.74), and 0.28 (0.09-0.89), respectively (p for trend=0.017). Compared with mostly sitting at the workplace, occupational physical activity of standing and walking were associated with a lower risk of bladder cancer (HR, 0.53 [95% CI, 0.32 to 0.85]). Hours of daily walking were not associated with the risk. The lower risk of bladder cancer was more evident for recreational sports (HR, 0.33 [95% CI, 0.10 to 1.00]), and for occupational standing and walking activity at work (HR, 0.57 [95% CI, 0.33 to 0.98]) among men.Conclusion Recreational sports participation and occupational physical activity were inversely associated with the risk of bladder cancer among Japanese, especially in men.

Television Viewing Time and Breast Cancer Incidence for Japanese Premenopausal and Postmenopausal Women: The JACC Study

Jinhong Cao,Ehab Salah Eshak,Keyang Liu,Isao Muraki,Renzhe Cui,Hiroyasu Iso,Akiko Tamakoshi 대한암학회 2019 Cancer Research and Treatment Vol.51 No.4

Purpose The evidence on effects of TV viewing time among premenopausal and postmenopausal women for breast cancer risk remains controversial and limited. Materials and Methods A prospective study encompassing 33,276 (17,568 premenopausal, and 15,708 postmenopausal) women aged 40-79 years in whom TV viewing time, menstrual, and reproductive histories were determined by a self-administered questionnaire. The follow-up was from 1988 to 2009 and hazard ratios (HRs) with 95% confidence intervals (CIs) of breast cancer incidence were calculated for longer TV viewing time in reference to shorter TV viewing time by Cox proportional hazard models. Results During 16.8-year median follow-up, we found positive associations between TV viewing time and breast cancer incidence with a borderline significant trend among total women and a significant trend among postmenopausal women. Among total women, the multivariable HRs (95% CIs) for risk of breast cancer in reference to < 1.5 hr/day of TV viewing time were 0.89 (0.59-1.34) for 1.5 to < 3.0 hr/day, 1.19 (0.82-1.74) for 3.0 to < 4.5 hr/day, and 1.45 (0.91-2.32) for  4.5 hr/day (p for trend=0.053) and among postmenopausal women, the corresponding risk estimates were 1.10 (0.42-2.88), 2.54 (1.11-5.80), and 2.37 (0.92-6.10) (p for trend=0.009), respectively. Conclusion Prolonged TV viewing time was associated with increased risk of breast cancer, especially among postmenopausal women.

Television Viewing Time and the Risk of Colorectal Cancer Mortality among Japanese Population: The JACC Study

Yuting Li,Ehab S. Eshak,Renzhe Cui,Kokoro Shirai,Keyang Liu,Hiroyasu Iso,Satoyo Ikehara,Akiko Tamakoshi,Shigekazu Ukawa,JACC Study Group 대한암학회 2021 Cancer Research and Treatment Vol.53 No.2

Purpose Sedentary behavior attributes to the increased risk of some cancers and all-cause mortality. The evidence is limited for the association between television (TV) viewing time, a major sedentary behavior, and risk of colorectal cancer death. We aimed to examine this association in Japanese population. Materials and Methods A prospective cohort study encompassed of 90,834 men and women aged 40-79 years with no prior history of colorectal cancer who completed a self-administered food frequency questionnaire, and provided their TV viewing information. The participants were followed-up from 1988-1990 to the end of 2009. The hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by the Cox proportional hazard regression for risk of colorectal cancer mortality according to TV viewing time. Results During the median 19.1-year follow-up period, we documented 749 (385 men and 364 women) colorectal cancer deaths. The multivariable-adjusted HRs for mortality from colorectal cancer were 1.11 (0.88-1.41) for 1.5 to < 3 hr/day, 1.14 (0.91-1.42) for 3 to < 4.5 hr/day and 1.33 (1.02-1.73) for ≥ 4.5 hr/day in comparison to < 1.5 hr/day TV watching; p-trend=0.038, and that for 1-hour increment in TV viewing time was 1.06 (1.01-1.11). Moreover, the multivariable-adjusted HR (95% CI) of colon cancer for 1-hour increment in TV viewing time was 1.07 (1.02-1.13). Age, body mass index, and level of leisure-physical activity did not show significant effect modifications on the observed associations. Conclusion TV viewing time is associated with the increased risk of colorectal cancer mortality among Japanese population, more specifically colon rather than rectal cancer.

Modifiable Risk Factors for Cardiovascular Disease in Korea and Japan

Ahmed Arafa,Hyeok-Hee Lee,Ehab S. Eshak,Kokoro Shirai,Keyang Liu,Jiaqi Li,Naharin Sultana Anni,Sun Young Shim,Hyeon Chang Kim,Hiroyasu Iso 대한심장학회 2021 Korean Circulation Journal Vol.51 No.8

Cardiovascular disease (CVD) is the leading cause of death and a major contributor to disability worldwide. Since the majority of cardiovascular events are preventable, identification of modifiable CVD risk factors and implementation of primordial prevention strategies should be a public health priority. In this aspect, the American Heart Association declared a strategic goal to reduce total CVD mortality in the US by 20% within 10 years via eliminating 7 major CVD risk factors (hypertension, diabetes, dyslipidemia, cigarette smoking, physical inactivity, obesity, and poor-quality diet) in 2010, and their strategy has been achieving. However, the applicability of similar metrics to prevent CVD among East Asians requires an in-depth investigation of the modifiable CVD risk factors based on national and regional evidence-based findings. Herein, this review article aims to discuss several modifiable risk factors for CVDs, using epidemiological evidence from cohort studies and nationally representative data of 2 East Asian countries: Korea and Japan.

Mechanical Properties and Anchorage Angle Optimization of Rock Mass with a Weak Intercalated Layer

Ke Yang,Xin Lyu,Juejing Fang,Shuai Liu,Zhen Wei,Wenjie Liu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

A weak intercalated layer has gradually become the key problem in roadway surrounding rock control in deep rock stress environment, and the selection of anchorage angle has a great influence on the stability of the intercalated rock. This study aimed to prepare weak intercalated layer-composited specimens with different dip angles and anchorage angles for the uniaxial compression test. The results showed that the strength curve of the composite specimens exhibited a single-peak variation trend of first decreasing and then increasing from 0° to 90° inclination variation, and the strength and strain reached the lowest value at 60° inclination angle. The failure modes of composite specimens with different dip angles could be divided into single splitting failure, coupled shear failure, and single shear failure. The initial strength of the unanchored specimen was basically the same as that of the anchored specimen, and with the increase in anchorage angle, the uniaxial strength first increased and then decreased. The appropriate anchorage angle range was 0° to 30°. Mainly slip deformation of the specimen occurred when the anchorage angle was smaller than 30°, and the deformation of the specimen mainly depended on the material of the bolt when the anchorage angle was larger than 30°. The strength variation model of the composite anchorage specimen was proposed, taking into account the stress of the bolt, the influence of the dip angle of the intercalated layer, and the anchorage angle of the structural plane.