Hideki Morimoto

Chiba University, Chiba-shi, Chiba-ken, Japan

Are you Hideki Morimoto?

Claim your profile

Publications (7)24.81 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: AIM: The aim of this study was to determine the relationship between the development of diabetes mellitus and high-sensitivity C-reactive protein (HsCRP) adjusted for various potential confounders. METHODS: This 5-year prospective cohort study was conducted at a Japanese steel factory and involved male workers who had received annual health screenings between 2005 and 2010. The 7392 male participants were aged 19-75years. The study endpoint, the development of diabetes mellitus, was defined as HbA(1c) greater or equal to 6.5% or the use of antidiabetic medication. The association between variables was investigated using pooled logistic regression adjusted for various covariates such as age, baseline body mass index (BMI) and increase in BMI from baseline, blood biochemistry, job schedule and job-related stress. RESULTS: The incidence rate of diabetes development per 1000person-years was 13.9. Multivariate analysis showed a significant relationship between the development of diabetes and elevated levels of baseline HsCRP and increases in levels from baseline. The Odds ratios for a 2.9-fold (±1 geometric standard deviation) increase in baseline HsCRP and increase in HsCRP level from baseline were 1.18 [95% confidence interval (CI): 1.03-1.34; P=0.018] and 1.21 (95% CI: 1.03-1.41; P=0.018), respectively. CONCLUSION: The present study has indicated that HsCRP is an independent predictor for the development of diabetes in men, together with various confounders such as BMI, type of job schedule and job-related stress.
    Diabetes & Metabolism 05/2012; · 2.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to examine the dose-response relationships between tobacco or alcohol consumption and the development of diabetes mellitus. An 8-year prospective cohort study was conducted in 8423 male workers who received annual health check-ups between 2002 and 2010 at a Japanese steel company. The endpoints were defined as an HbA(lc)≥6.1% or taking any anti-diabetic medication. The dose-response relationships of tobacco or alcohol consumption were investigated using a proportional hazards regression with time-dependent covariates selected from baseline age, body mass index, mean arterial pressure, total serum cholesterol, aspartate aminotransferase, creatinine and uric acid, shift work or day work, and habitual exercise by stepwise selection method. A positive dose-response relationship between tobacco consumption and the development of diabetes mellitus was observed, with a significantly higher hazard ratio (HR) seen with higher tobacco consumption (11-20 cigarettes/day, HR 1.26 [95% confidence interval (CI), 1.00-1.59], ≥21 cigarettes/day, HR 1.54 [95%CI, 1.20-1.97]). In contrast, we observed a negative dose-response relationship between alcohol consumption and the development of diabetes mellitus, with a significantly lower HR with higher weekly alcohol consumption (7.0-13.9gou/week [154-307g/week], HR 0.73 [95% CI, 0.55-0.97], ≥14.0gou/week [308g/week], HR 0.75 [95% CI, 0.57-0.98]). The results indicated that decreasing tobacco consumption will achieve significant prevention of diabetes mellitus. On the other hand, we observed a significant, negative dose-response relationship between alcohol consumption and the development of diabetes mellitus, in contrast to previous studies that reported a positive relationship in the Japanese population.
    Drug and alcohol dependence 03/2012; 125(3):276-82. · 3.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors estimated the benchmark durations (BMDs) and their 95% lower confidence limit (BMDL) for the reference duration of shiftwork for weight gain. A 14-yr prospective cohort study was conducted in male workers at a Japanese steel company (n = 7254) who had received annual health check-ups between 1991 and 2005. The endpoints in the study were either a 5%, 7.5%, or 10% increase in body mass index (BMI) during the period of observation, compared to the BMI at entry. The association between the duration of shiftwork and weight gain was investigated using multivariate pooled logistic regression analyses with stepwise selection of covariates, including age, BMI measured during the study, drinking and smoking habits, and habitual exercise. The BMDL/BMD for shiftwork in subjects aged in their 40s or ≥50 yrs was estimated using benchmark responses (BMRs) of 5% or 10% and parameters for the duration of shiftwork and other covariates. For workers aged in their 40s, the BMDL/BMD for shiftwork with a BMR of 5% was 18.6/23.0 yrs (≥7.5%) and 16.9/19.4 yrs (≥10%). For workers aged ≥50 yrs, the BMDL/BMD with a BMR of 5% was 22.9/28.2 yrs (≥7.5%) and 20.6/23.6 yrs (≥10%). The reference duration of shiftwork that associated with weight gain was shown to be at least 17 yrs in middle-aged workers. Special attention should be paid to prevent weight gain at an earlier stage and not when this increase in weight has become apparent.
    Chronobiology International 10/2010; 27(9-10):1895-910. · 4.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to calculate the benchmark doses (BMD) and their 95% lower confidence boundary (BMDL) for the threshold number of years of shift work associated with a relative increase in haemoglobin A1c (HbA(1c)), an index of glucose metabolism. A 14-year prospective cohort study was conducted in male workers at a Japanese steel company (n=7104) who had received annual health check-ups between 1991 and 2005. The endpoints were either a 10%, 15%, 20%, 25% or 30% increase in HbA(1c) levels during the observation period, compared to HbA(1c) at entry to the study. The associations between years of shift work and increases in HbA(1c) were investigated using pooled logistic regression, adjusted for age, body mass index, mean arterial pressure, total serum cholesterol, creatinine, alanine aminotransferase, gamma-glutamyl transpeptidase, uric acid, drinking habits, smoking habits and habitual exercise. The BMDL/BMD for years of shift work were calculated using benchmark responses (BMRs) of 5% or 10% and parameters for duration of shift work and other covariates. Assuming a mean age of 53 years in workers aged 50 years or older, the BMDL/BMD for years of shift work with a BMR of 5% were 17.8/23.9 (> or = 15%), 15.7/18.7 (> or = 20%), 18.9/22.7 (> or = 25%) and 25.2/31.7 (> or = 30%). With a BMR of 10%, the respective values were 29.5/39.7 (> or = 15%), 24.3/28.9 (> or = 20%), 27.3/32.7 (> or = 25%) and 34.1/42.9 (> or = 30%). These results suggest that special attention should be paid to middle-aged workers whose years of shift work exceeds these threshold times.
    Occupational and environmental medicine 08/2010; 67(8):532-7. · 3.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to estimate the benchmark doses (BMD) and their 95% lower confidence limits (BMDL) for the threshold number of years of alternating shift work associated with a relative increase in serum total cholesterol level (T-Cho), as an index of lipid metabolism. We conducted a 14-year prospective cohort study among male workers (N=6886) at a Japanese steel company who had received annual health check-ups between 1991 and 2005. The endpoints were either a 20, 25, 30, 35, 40 or 45% increase in T-Cho levels during the observation period, compared to T-Cho at baseline. We investigated the associations between the years of alternating shift work and the relative increases in T-Cho using pooled logistic regression, adjusted for other potential covariates. We estimated the BMDL and BMD for years of alternating shift work among 40-, 50-, or >50-year old subjects using benchmark responses (BMR) of 5 or 10% and parameters for the duration of alternating shift work and other covariates. Assuming a mean age of 44 years among workers in their 40s, the BMDL/BMD for years of alternating shift work with a BMR of 5% were 21.0/28.0 (> or =20%), 21.3/26.1 (> or =25%), 24.1/28.8 (> or =30%), 25.6/29.8 (> or =35%), 27.1/31.5 (> or =40%), and 27.7/32.1 (> or =45%). The threshold number of years of alternating shift work that caused a 5% increase in T-Cho was shown to be > or =21 years among middle-aged workers. Special attention should be paid to influence the process at an earlier stage and not when the risk has already materialized.
    Scandinavian Journal of Work, Environment & Health 03/2010; 36(2):142-9. · 3.10 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Detailed information on the expected physiologic changes after smoking cessation is practically useful to encourage people to stop smoking. Furthermore, weight increase after cessation may affect such physiologic changes. This article aims to evaluate the effect of smoking cessation on annual changes in body weight, blood pressure, and blood biochemistry. This study analyzed the results of annual health examinations from 1991 to 2005 in male Japanese workers in 2009. Subjects classified as stopping smoking (n=445) responded initially as smokers in a self-administered questionnaire (baseline year) and then answered consistently as nonsmokers for 3 subsequent years. Of the 2672 smokers identified in the study, 2403 subjects who had data available for at least 4 successive years were selected as controls. The time course of physiologic and laboratory data was analyzed using a linear mixed model. Data adjusted for age, type of job schedule, drinking and physical activity showed that subjects who stopped smoking had significantly greater increases in weight, BMI, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and uric acid and a greater decrease in hemoglobin in the 3 years following smoking cessation than continuing smokers. Additional adjustment for change in BMI from baseline negated the significant deterioration in systolic and diastolic blood pressure and total cholesterol that occurred following smoking cessation. Increase in body weight, blood pressure, and blood biochemistry can continue for at least 3 years after smoking cessation. This study also indicated that these increases were related to the weight increase that occurred after smoking cessation.
    American journal of preventive medicine 02/2010; 38(2):192-200. · 4.24 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the effect of smoking initiation on annual changes in body weight, blood pressure, and blood biochemistry. This study analyzed the results of annual health examinations from 1991 to 2005 in male Japanese workers. Subjects who started smoking (n=214) initially responded as non-smokers in a self-administered questionnaire (baseline year) and then answered consistently as smokers for 3 subsequent years. Out of 2547 non-smokers, we selected 1589 controls who had data available for at least four successive years. The time course of physiological and laboratory data was analyzed using a linear mixed model. A significant temporal decrease from baseline in body mass index (first year, -0.1 kg/m(2)), diastolic blood pressure (second year, -1.5 mm Hg) and gamma-glutamyl transpeptidase (second year, -3.5 IU/L) was observed for subjects who started smoking. An opposite pattern was observed in non-smokers. On average, those who started smoking had significantly lower body mass index (first year, -0.2 kg/m(2); second year, -0.2 kg/m(2)), systolic blood pressure (second year, -2.1 mm Hg), diastolic blood pressure (second year, -2.0 mm Hg), and gamma-glutamyl transpeptidase (second year, -4.5 IU/L) than non-smokers. In this study, smoking initiation did not yield clinically significant long-term benefits with respect to physiological or biochemical outcomes. These results are important because few studies have tracked these types of changes longitudinally from initiation through 3 years of follow-up.
    Preventive Medicine 04/2009; 48(6):567-71. · 3.50 Impact Factor