Akihiro Toyota

Objective: To examine associations between occupation and overall and site-specific cancer risk in Japan. Methods: We conducted a multicenter, hospital-based matched case–control study using the Inpatient Clinico-Occupational Survey of the Rosai Hospital Group (2005–2023), including 146,994 cancer cases and 278,244 matched controls. Conditional logistic regression was used to estimate sex-specific adjusted odds ratios by occupations. Results: Occupational disparities in cancer risk were observed, with more pronounced associations among men than women. Elevated risks were identified in manual and transport-related occupations, whereas lower risks were observed in selected professional occupations. Site-specific patterns varied by cancer type and sex. Conclusions: Occupation is associated with cancer risk in Japan, showing distinct sex-specific and site-specific patterns. These findings underscore the importance of occupational context in cancer epidemiology and provide a hypothesis-generating framework highlighting behavioral and detection-related factors.

Objectives: To investigate the association between occupation and Parkinson’s disease (PD) risk and whether patients with PD change occupation after onset. Design: A matched case–control study using secondary analysis of the Inpatient Clinico-Occupational Survey of the Rosai Hospital Group in Japan. Setting: A nationwide multicentre inpatient dataset in Japan from 2005 to 2021. Participants: The PD group comprised 2205 inpatients diagnosed with PD (International Statistical Classification of Diseases and Related Health Problems, 10th Revision code G20) and 10 436 matched controls without PD, matched for age, sex, year of admission and hospital. Primary outcome measure: Associations between the longest-held occupation—classified by industry (blue-collar, service, white-collar) and occupational class (blue-collar workers, service workers, professionals, managers)—and PD risk. Secondary outcome measure: Occupations and industries with increased PD risk; occupational changes before and after diagnosis among participants aged <60 years; and associations of PD risk with chemical exposure, smoking status and sex. Results: After adjustment for smoking and alcohol, professionals in the service (OR=2.01, 95% CI 1.24 to 3.25) and white-collar (OR=1.33, 95% CI 1.10 to 1.61) industries had higher PD risk than service workers. Doctors, dentists, veterinarians and pharmacists showed elevated risk. Among 160 PD patients, 47% were unemployed, 20% left voluntarily and 30% continued working after diagnosis. Chemical handling was not associated with PD risk after adjustment of multiple comparisons. Former or current smokers among blue-collar and service workers in blue-collar industry had a decreased risk of PD. Conclusions: Professionals in the service and white-collar industries, particularly those in healthcare occupations, had a higher risk of PD. Approximately 20% became unemployed after diagnosis.

Objectives While there is growing evidence that physical activity reduces the risk of hepatocellular carcinoma (HCC), the impact of occupational physical activity and sedentary behaviour remains unclear. This study aimed to investigate the associations between occupational physical activity and sedentary behaviour and HCC risk. Design Matched case-control study. Setting Nationwide multicentre, hospital-inpatient data set in Japan, from 2005 to 2021. Participants The study included 5625 inpatients diagnosed with HCC and 27 792 matched controls without liver disease or neoplasms. Participants were matched based on sex, age, admission date, and hospital. Primary measures The association between levels of occupational physical activity (low, medium, high) and sedentary time (short, medium, long) with the risk of HCC. Secondary measures Stratification of HCC risk by viral infection status (hepatitis B/C virus), alcohol consumption levels and the presence of metabolic diseases (hypertension, diabetes, dyslipidaemia, obesity). Results High occupational physical activity was not associated with HCC caused by hepatitis B/C virus infection in men. In women, high occupational physical activity was associated with a reduced risk of non-viral HCC, with ORs (95% CIs) of 0.65 (0.45–0.93). Among patients with non-viral HCC, medium occupational physical activity combined with medium alcohol intake further decreased the HCC risk in men with an OR of 0.70 (0.50–0.97), while high occupational physical activity combined with lowest alcohol intake decreased the HCC risk in women with an OR of 0.69 (0.48–0.99). Men and women with medium sedentary time had a lower HCC risk compared with those with long sedentary time, with ORs of 0.88 (0.79–0.98) in men and 0.77 (0.62–0.97) in women, respectively. In patients without viral infection or alcohol use, medium sedentary time reduced the HCC risk associated with fatty liver disease without comorbid metabolic diseases in women. Conclusions High levels of occupational physical activity and/or medium periods of sedentary time are associated with a reduced risk of HCC, particularly non-alcoholic steatohepatitis.

【背景および目的】循環器病対策推進計画で，治療と仕事の両立支援体制の整備が提唱されているが，脳卒中患者の就労状況自体不明な点が多い．【方法】2013年4月から2023年3月までに全国労災病院に救急入院加療された脳卒中患者34,809例の年齢，転帰，退院先，発症時点の就労状況（職業・産業分類，雇用形態）を検討した．【結果】全脳卒中患者のうち形態問わず就労していた者は7,333例（21%）で，病型はくも膜下出血9.8%，脳梗塞64.3%，脳出血26.0%であった．非就労者との比較では出血性脳卒中が多く，特に女性のくも膜下出血が多かった．全年齢で正規雇用者は男性で多いが，30代以降でその性差が著明だった．病型による職種・業種・雇用形態の違いを認めた．64歳未満の両立支援対象者の推計は，正規雇用者で7.2%，非正規雇用者を含めて10.3%であった．【結論】脳卒中患者の早期離職の予防や復職支援の導入が急性期医療機関に望まれる．

Objective: The aim of the study is to develop a job-exposure matrix for sedentary behavior and assess its relationship with noncommunicable diseases. Methods: We constructed a job-exposure matrix using occupational and industry classifications combined with data on daily average sitting durations from 41,718 individuals. This matrix was then applied to a cohort of 706,939 participants in a case-control study to explore the link between sedentary behavior and noncommunicable disease risks. Results: The matrix effectively identified sedentary behavior across different occupational groups. Using the matrix to assess sedentary behavior, associations were found between increased sedentary activity and heightened risks of diabetes, acute myocardial infarction, and endometrial cancer, while a reduced risk was observed for stroke. Conclusions: The job-exposure matrix provides valuable insights into the health impacts of sedentary behavior in the workplace, underscoring significant disease risks associated with prolonged inactivity.

Précis: In this case-control study of the Japanese population, including 3207 glaucoma cases, alcohol consumption patterns such as frequency and quantity showed a positive association with glaucoma prevalence. Purpose: To examine the association between alcohol consumption patterns and glaucoma. Subjects and Methods: This case-control study evaluated 3207 cases with glaucoma and 3207 matched controls. Patients over 40 years of age were included from 1,693,611 patients admitted to 34 hospitals in Japan. Detailed alcohol consumption patterns (drinking frequency, average daily drinks, and total lifetime drinks) were obtained, as well as various confounding factors, including smoking history and lifestyle-related comorbidities. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% CIs for glaucoma prevalence. Results: Drinking frequency showed an association with glaucoma for “a few days/week” (OR, 1.19; 95% CI, 1.03–1.38) and “almost every day/week” (OR, 1.40; 95% CI, 1.18–1.66). Average daily drinks showed an association for “>0–2 drinks/day” (OR, 1.16; 95% CI, 1.03–1.32). Total lifetime drinks showed an association for “>60–90 drink-year” (OR, 1.23; 95% CI, 1.01–1.49) and “>90 drink-year” (OR, 1.23; 95% CI, 1.05–1.44). As alcohol consumption levels differed considerably between men and women, additional analyses were conducted separately for men and women. Among men, drinking frequency of “a few days/week” and “almost every day/week,” average daily drinks of “>0–2 drinks/day” and “>2–4 drinks/day,” and total lifetime drinks of “>60–90 drink-year” and “>90 drink-year” had an association with glaucoma. Conversely, among women, neither drinking frequency, average daily drinks, nor total lifetime drinks were associated. Conclusions: Both the frequency and quantity of alcohol consumption were associated with glaucoma. Further research on gender differences is warranted.

A person’s occupation may increase his/her risk for developing inflammatory bowel disease (IBD). This study investigated the association between risk for later-onset of IBD and both specific occupa...

We aimed to examine whether the number of types of hazardous operations at work experienced through a lifetime is associated with cancer incidence, and additionally examined the combined effects with lifestyle‐related factors. Using a nationwide, multicenter, hospital inpatient dataset (2005‐2015), we conducted a matched case‐control study with 1 149 296 study subjects. We classified the participants into those with none, 1, or 2 or more types of hazardous operation experience, based on information of special medical examinations taken, mandatory in Japan for workers engaged in hazardous operations. Using those with no experience as the reference group, we estimated the odds ratios for cancer incidence (all sites, lung, stomach, colon and rectum, liver, pancreas, bile duct, and bladder) by conditional logistic regression with multiple imputations. We also examined the effects of the combination with hazardous operations and lifestyle‐related factors. We observed increased risks for cancer of all sites, and lung, pancreas, and bladder cancer associated with the experience of hazardous operations. Multivariable‐adjusted ORs (95% CIs) of cancer incidence of all sites were 1 (reference), 1.16 (1.12, 1.21), and 1.17 (1.08, 1.27) for none, 1, and 2 or more types of hazardous operation experience, respectively (P for trend <.001). Potential combined associations of hazardous operations with smoking were observed for lung, pancreas, and bladder cancer, and with diabetes for pancreas cancer. Engaging in hazardous operations at work and in combination with lifestyle‐related factors may increase the risk of cancer. We highlight the potential for those engaged in hazardous work to avoid preventable cancers.

要旨：わが国の脳卒中大規模調査研究は少なく，特にくも膜下出血に関しては全体の6％程度であるため，疫学的に不明な点も多い．代表的な「脳卒中データバンク2015」でさえ，局在明瞭な破裂脳動脈瘤は4,153 例と少ないため，労災病院病職歴調査研究データから局在明瞭な破裂脳動脈瘤3,963 例を抽出し，その特徴を明らかにする目的で分析した．破裂脳動脈瘤は，女性が男性の2 倍多く，平均年齢は男性60.1 歳，女性68.9 歳で，ピークは男性60 歳代，女性70 歳代であった．局在はウィルス脳動脈輪前半が80％を占め，前交通動脈（29％）・中大脳動脈（27％）・内頸動脈周囲（23％）の順で多かった．局在比率は，脳卒中データバンクでは男性で明らかに前交通動脈が多いが，本研究では男女差を認めなかった．男性で中大脳動脈の発症年齢が若い傾向があった．さらに24 時間以内死亡例を抽出すると，中大脳動脈が多く，特に男性で有意であった．詳細解明には全国レベルでの全例調査が望まれる．