Kozo Tatara

Serum uric acid and risk for development of hypertension and impaired fasting glucose or Type II diabetes in Japanese male office workers

We examined the association of serum uric acid (SUA) with development of hypertension (blood pressure ≥ 140/90 mmHg and/or medication for hypertension) and impaired fasting glucose (IFG) (a fasting plasma glucose level 6.1–6.9 mmol/l) or Type II (non-insulin-dependent) diabetes (a fasting plasma glucose level ≥ 7.0 mmol/l and/or medication for diabetes) over a 6-year follow-up among 2310 Japanese male office workers aged 35–59 years who did not have hypertension, IFG, Type II diabetes, or past history of cardiovascular disease at study entry. After controlling for potential predictors of hypertension and diabetes, the relative risk for hypertension compared with quintile 1 of SUA level was 1.27 [95% confidence interval (CI): 1.00–1.62] for quintile 2, 1.34 (95% CI: 1.08–1.74) for quintile 3, 1.48 (95% CI: 1.18–1.89) for quintile 4, and 1.58 (95% CI: 1.26–1.99) for quintile 5 (p for trend <0.001). The respective multivariate-adjusted relative risks for IFG or Type II diabetes compared with quintile 1 of SUA level were 1.55 (95% CI: 0.95–2.63), 1.62 (95% CI: 0.98–2.67), 1.61 (95% CI: 1.01–2.58), and 1.78 (95% CI: 1.11–2.85) (p for trend = 0.030). The association between SUA level and risk for hypertension and IFG or Type II diabetes was stronger among men with a body mass index (BMI) <24.2 kg/m2 than among men with a BMI ≥ 24.2 kg/m2, although the absolute risk was greater in more obese men. These results indicate that SUA level is closely associated with an increased risk for hypertension and IFG or Type II diabetes.

Cigarette smoking and risk for impaired fasting glucose and type 2 diabetes in middle-aged Japanese men.

The prevalence of type 2 diabetes in Japan has increased in the past decade, in tandem with the rapid westernization of lifestyle (1). This disorder of impaired insulin secretion and insulin resistance is associated with increased risk for cardiovascular disease, renal disease, and retinopathy (2-4). Although age, family history of diabetes, obesity, alcohol consumption, and reduced physical activity are well-known risk factors for type 2 diabetes (5-12), the association of smoking with development of type 2 diabetes is not well understood. Longitudinal studies from the Netherlands, the United States, and Japan (11-14) have reported that cigarette smoking may be an independent risk factor for type 2 diabetes. However, one study found a monotonic association between cigarette smoking and type 2 diabetes (14), but two found a nonmonotonic association (12, 13). Furthermore, a cohort study in the United Kingdom failed to show an independent association between cigarette smoking and type 2 diabetes (15). These inconclusive results may have resulted in part from ethnic or lifestyle differences in the study samples but also may have been strongly influenced by different methods used to diagnose type 2 diabetes. In the western studies (11, 12, 15), the diagnosis of type 2 diabetes was ascertained by a mailed questionnaire. In one Japanese study (13), type 2 diabetes was diagnosed by measuring the 75-g oral glucose tolerance test in persons with both glucosuria and a fasting plasma glucose level of 6.1 mmol/L (110 mg/dL) or more. In another Japanese study (14), type 2 diabetes was defined according to newer criteria (a fasting plasma glucose level 7.0 mmol/L [126 mg/dL]) (16, 17) or a physician diagnosis of type 2 diabetes. Because the American Diabetes Association (ADA) in 1997 (16) and the World Health Organization (WHO) in 1998 (17) recommended that estimates of diabetes incidence in epidemiologic studies be based on the fasting plasma glucose level, type 2 diabetes can be inexpensively and easily diagnosed in a large population. Using serial annual health examinations at the workplace and the new ADA and WHO criteria (16, 17), we performed a longitudinal population study to prospectively examine the association of cigarette smoking with development of impaired fasting glucose and type 2 diabetes in middle-aged Japanese men. Methods Study Cohort Our study is an ongoing cohort investigation designed to clarify risk factors for major diseases, including hypertension, dyslipidemia, and diabetes, among Japanese male office workers at T Corporation, one of the biggest building contractors in Osaka, Japan. The Industrial Safety and Health Law in Japan requires the employer to conduct annual health examinations of all employees; the employee data, which are anonymous, are available for research with the approval of the employer. To evaluate the association of cigarette smoking with development of impaired fasting glucose and type 2 diabetes, surveillance of the incidence of impaired fasting glucose and type 2 diabetes was conducted between 1994 and 1999. All Japanese male office workers 35 to 59 years of age in May 1994 were invited to complete a survey (n =1581); the participation rate was 99.9% (n =1580). Of 1580 potential participants, 269 (17.0%) were excluded: One hundred six (6.7%) had type 2 diabetes, 67 (4.2%) had impaired fasting glucose, and 114 (7.2%) were taking antihypertensive medication. Thus, the baseline sample consisted of 1311 men. We also excluded 45 men who did not participate in consecutive annual health examinations during follow-up. The final study sample for analysis therefore consisted of 1266 men. Men in whom impaired fasting glucose and type 2 diabetes were found during repeated surveys through May 1999 were defined as having incidental cases of impaired fasting glucose and type 2 diabetes. To determine the incidence of type 2 diabetes, incidental cases of impaired fasting glucose were followed and were considered type 2 diabetes if this condition developed. Fourteen participants who started taking medication for diabetes during the observation period were considered to have incidental cases of type 2 diabetes. Owing to the age range of the study sample, all cases of impaired fasting glucose and type 2 diabetes were diagnosed after 35 years of age and were therefore classified as impaired fasting glucose and type 2 diabetes. Study Design Fasting plasma glucose levels were measured at annual health examinations in May from 1994 to 1999. The participants were asked to fast for at least 8 hours and to avoid smoking and heavy physical activity for more than 2 hours before the examinations. Blood samples were drawn from an antecubital vein. Fasting plasma glucose levels were measured by glucose dehydrogenase spectrophotometry with Olympus AU-5000 equipment in 1994 and Olympus AU-5200 equipment in 1995 to 1999 (Olympus Japan Co., Ltd., Tokyo, Japan) at FALCO Biosystems Tokyo Ltd., Tokyo, Japan. Quality control of the laboratory was maintained by an internal method, and the interassay and intra-assay coefficients of variation for plasma glucose were no more than 3% from 1994 to 1999. Normal fasting glucose, impaired fasting glucose, and type 2 diabetes were defined by using the ADA and WHO criteria (16, 17). Normal fasting glucose was defined as a fasting plasma glucose level less than 6.1 mmol/L (110 mg/dL). Impaired fasting glucose was defined as a fasting plasma glucose level of at least 6.1 but less than 7.0 mmol/L (126 mg/dL). Type 2 diabetes was defined as a fasting plasma glucose level of 7.0 mmol/L or greater or receipt of hypoglycemic medications (because not every participant underwent an oral glucose tolerance test). Annual health examinations included medical history; physical examination; anthropometric measurements; blood pressure measurement; biochemical measurements; and a questionnaire on health-related behaviors, such as smoking, alcohol consumption, and physical activity. Medical history and history of use of prescription drugs were assessed by the examining physicians. Family history of diabetes was defined as a mother, father, sister, or brother with diagnosed diabetes. Body mass index was used as a measure of overall obesity and was calculated as body weight/height 2 (kg/m2). After a 5-minute rest in a quiet room, systolic and diastolic blood pressures were measured on the right arm by using a standard mercury sphygmomanometer. The Olympus AU-5000 spectrophotometer was also used to measure total cholesterol, high-density lipoprotein cholesterol, triglycerides, and uric acid. The hematocrit was determined by using a Sysmex E-4000 autoanalyzer (Toa Medical Electronics Co., Ltd., Tokyo, Japan). With regard to health-related behaviors, the questionnaire asked about smoking habits (never, past, or current smoker); past or current smokers were asked about the number of cigarettes smoked per day and the duration of smoking in years. Current smokers were subdivided into three groups by the number of cigarettes smoked daily: 1 to 20 cigarettes/d, 21 to 30 cigarettes/d, and 31 or more cigarettes/d. A pack-year was defined as smoking 20 cigarettes/d for 1 year. Participants were categorized by number of pack-years into five groups: 0 pack-years, 0.1 to 20.0 pack-years, 20.1 to 30.0 pack-years, 30.1 to 40.0 pack-years, and 40.1 or more pack-years. The questions about alcohol intake included items about the type of alcoholic beverage, the frequency of alcohol consumption per week, and the usual amount consumed daily. Weekly alcohol intake was calculated and converted to daily alcohol consumption (grams of ethanol per day) by using standard Japanese tables. Participants were asked about the type and weekly frequency of leisure-time physical activity. Physical exercise was defined as participation in any physical activity, such as jogging, bicycling, swimming or tennis, that was performed long enough to work up a sweat. Statistical Analysis The chi-square test and one-way analysis of variance were used to analyze the statistical differences among participant characteristics at enrollment according to smoking status. For each participant, person-years of follow-up were calculated from 1) the date of enrollment to the date of diagnosis of impaired fasting glucose or type 2 diabetes or 2) the date of follow-up, whichever came first. The follow-up rate was 95.6% of the total potential person-years of follow-up. Cox proportional-hazards models (18) were used to evaluate the association between smoking status and the development of impaired fasting glucose or type 2 diabetes. Data were adjusted first for age alone, then for the following multiple covariates: age; body mass index; alcohol consumption; physical activity; family history of diabetes; systolic and diastolic blood pressure; levels of fasting plasma glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, and uric acid; and hematocrit. Potential confounding factors were treated as categorical variables: age, body mass index, systolic and diastolic blood pressure, fasting plasma glucose level, total cholesterol level, high-density lipoprotein cholesterol level, triglyceride level, uric acid level, and hematocrit (all graded from 1 through 5 [first through fifth quintiles]); alcohol consumption (graded as 1 [none] or as quartile 1 [grade of 2] to quartile 4 [grade of 5] for drinkers); regular physical exercise (graded from 1 to 3 [hardly ever, once per week, or twice or more per week]); and family history of diabetes (no or yes). The linear trends in risks were evaluated by using the median value for each category of smoking status. Data were analyzed by using the SPSS/PC statistical package (SPSS Inc., Chicago, Illinois). All reported P values are two-tailed; those less than 0.05 were considered statistically significant. Role of the Funding Source The funding agencies did not participate in the collection, analysis,

Declining trends in blood pressure level and the prevalence of hypertension, and changes in related factors in Japan, 1956–1980

Trends in age-specific and age-adjusted blood pressure and the prevalence of hypertension were obtained from the National Nutrition Survey of Japan, 1956-1980. The national trends in the age-adjusted blood pressure of people (30-69 years old) in Japan during the 1956-1980 period show an increasing pattern reaching a peak around 1964 followed by a decreasing pattern. To explore the possible factors which have contributed to the change in blood pressure levels, we analyzed the relationship between the blood pressure and several possible factors, including the rate of treatment for cardiovascular diseases (CVD) for men and women, annual salt and alcohol consumption per captia and body mass index (MBI) for men and women. Only alcohol consumption was considered in the analysis of men because women in Japan still tend to drink relatively little alcohol. In simple descriptive analyses, the increasing trend in the treatment rates of CVD seemed to be related to the decrease in the blood pressure level and in the prevalence rate of hypertension for both men and women. The impact of treatment rate seemed to overcome the adverse influence of the increasing trends in BMI. Recent decrease in salt consumption may account in part for the later period of the decreasing trends in blood pressure level and the prevalence of hypertension. In multiple regression analysis using these time series data, CVD, BMI and alcohol consumption were significantly related to blood pressure level and the prevalence of hypertension, although salt was not significant in these analyses.

Urinary and Fecal Incontinence in a Community‐Residing Older Population in Japan

OBJECTIVE: To estimate the prevalence and risk factors of urinary and fecal incontinence among a community‐residing older population in Japan.

Serum γ-glutamyltransferase and development of impaired fasting glucose or type 2 diabetes in middle-aged Japanese men

Abstract.  Nakanishi N, Nishina K, Li W, Sato M, Suzuki K, Tatara K (Osaka University Graduate School of Medicine, Osaka; and Japan Labor and Welfare Association, Tokyo; Japan). Serum γ‐glutamyltransferase and development of impaired fasting glucose or type 2 diabetes in middle‐aged Japanese men. J Intern Med 2003; 254: 287–295.

Effect of physical exercise on mortality in patients with Parkinson's disease

Public health nurses visited and followed up for more than one year 438 patients with Parkinsons disease living in Osaka. The follow‐up period averaged 4.1 years, during which 71 deaths were observed. The patients were classified according to the degree of physical exercise they performed, and the ratios of observed to expected deaths were calculated. The exercising group showed the lowest ratio of 1.68 (1.45 for patients able to walk independently, and 1.89 for those could not) while all patients exhibited a ratio of 2.47. Multivariate analysis using Coxs proportional hazard model, adjusted for age, sex, walking ability and duration of disease at study entry, showed that, compared with the exercising group, the non‐exercising patients had a hazard ratio of 1.83.

White blood-cell count and the risk of impaired fasting glucose or Type II diabetes in middle-aged Japanese men.

Abstract.Aims/hypothesis: To investigate the association between white blood-cell (WBC) count and the development of diabetes, independent of cigarette smoking. Methods: We examined 2953 Japanese men who were office workers and between 35 and 59 years of age and who did not have impaired fasting glucose (IFG) (a fasting glucose concentration of 6.1–6.9 mmol/l), Type II (non-insulin-dependent) diabetes mellitus (a fasting glucose concentration of ≥ 7.0 mmol/l or more or receipt of hypoglycaemic medication), medication for hypertension, and a history of cardiovascular disease. Fasting glucose concentrations were measured at annual health examinations from May 1994 through May 2000. Results: After controlling for potential predictors of diabetes, the relative risk for IFG or Type II diabetes mellitus compared with a WBC count of less than 5.3 · 109 cells/l was 1.2 (95 %-CI, 0.6–2.3), 1.6 (CI, 0.8–3.1), and 2.5 (CI, 1.2–5.1) among non-smokers (p for trend = 0.009): and 1.0 (CI, 0.4–2.5), 2.3 (CI, 1.0–5.1), and 3.1 (CI, 1.4–7.1) among ex-smokers (p for trend = 0.001) with WBC counts of 5.3–6.1, 6.2–7.2, and 7.3 · 109 cells/l or more, respectively. Among current smokers, the respective multivariate-adjusted relative risks for IFG or Type II diabetes mellitus were 1.1 (CI, 0.6–2.1), 1.4 (CI, 0.8–2.4), and 1.2 (CI, 0.7–2.1) (p for trend = 0.460). Conclusion/hypothesis: Although the selection of a rigorously normoglycaemic cohort might have had an influence on these observations, higher WBC counts seem to predict the development of IFG or Type II diabetes mellitus, primarily in non-smokers. [Diabetologia (2002) 45: 42–48]

Long working hours and risk for hypertension in Japanese male white collar workers

STUDY OBJECTIVE To evaluate the association of long working hours with the risk for hypertension. DESIGN A five year prospective cohort study. SETTING Work site in Osaka, Japan. PARTICIPANTS 941 hypertension free Japanese male white collar workers aged 35–54 years were prospectively examined by serial annual health examinations. Men in whom borderline hypertension and hypertension were found during repeated surveys were defined as incidental cases of borderline hypertension and hypertension. MAIN RESULTS 336 and 88 men developed hypertension above the borderline level and definite hypertension during the 3940 and 4531 person years, respectively. After controlling for potential predictors of hypertension, the relative risk for hypertension above the borderline level, compared with those who worked < 8.0 hours per day, was 0.63 (95% confidence intervals (CI): 0.43, 0.91) for those who worked 10.0–10.9 hours per day and 0.48 (95% CI: 0.31, 0.74) for those who worked ⩾ 11.0 hours per day. The relative risk for definite hypertension, compared with those who worked < 8.0 hours per day, was 0.33 (95% CI: 0.11, 0.95) for those who worked ⩾ 11.0 hours per day. The multivariate adjusted slopes of diastolic blood pressure (DBP) and mean arterial blood pressure (MABP) during five years of follow up decreased as working hours per day increased. From the multiple regression analyses, working hours per day remained as an independent negative factor for the slopes of systolic blood pressure, DBP, and MABP. CONCLUSIONS These results indicate that long working hours are negatively associated with the risk for hypertension in Japanese male white collar workers.

Clustered features of the metabolic syndrome and the risk for increased aortic pulse wave velocity in middle-aged Japanese men.

The association between different features of the metabolic syndrome (MS) (obesity, hyper tension, hypercholesterolemia, low high-density lipoprotein cholesterol level, hypertriglyc eridemia, high fasting plasma glucose level, and hyperuricemia) and the risk for increased aortic pulse wave velocity (PWV) of ≥ 8.0 m/sec was examined in 2431 Japanese men aged 35 to 54 years who were not taking antihypertensive medication. After controlling for age, cigarette smoking, and alcohol intake, the odds ratios for increased aortic PWV in subjects with 1, 2, 3, and ≥ 4 features of the MS, compared with those without features of the MS, were 1.35 (95% Cl, 0.86 to 2.11), 1.90 (95% Cl, 1.18 to 3.06), 1.57 (95% Cl, 0.89 to 2.76), and 2.38 (95% Cl, 1.26 to 4.49), respectively (p for trend = 0.003). A 9-year longitudinal study was also performed to prospectively examine the association between clustered features of the MS and the devel opment of increased aortic PWV in 2073 men without aortic stiffness with a PWV <8.0 m/sec and without antihypertensive medication during the follow-up period. The multivariate-adjusted hazard ratios for the incidence of increased aortic PWV in subjects with 1, 2, 3, and ≥ 4 features of the MS, compared with those without features of the MS, were 1.39 (95% Cl, 1.10 to 1.77), 1.46 (95% Cl, 1.11 to 1.92), 1.75 (95% Cl, 1.27 to 2.40), and 2.22 (95% Cl, 1.52 to 3.25), respec tively (p for trend < 0.001). These results suggest that clustered features of the MS are closely associated with the risk for increased aortic PWV in middle-aged Japanese men.

Cigarette smoking and risk for hearing impairment : A longitudinal study in Japanese male office workers

The association of cigarette smoking with development of hearing impairment (loss of 30 dB at 1000 Hz and 40 dB at 4000 Hz) over a 5-year follow-up was studied in 1554 non–hearing-impaired Japanese male office workers who ranged in age from 30 to 59 years. After controlling for potential predictors of hearing impairment, the relative risk for low-frequency hearing impairment compared with never smokers was 1.12 (95% confidence interval [CI], 0.57 to 2.17) for ever-smokers, 1.21 (95% CI, 0.65 to 2.25) for current smokers of 1 to 20 cigarettes/day, 1.35 (95% CI, 0.70 to 2.61) for current smokers of 21 to 30 cigarettes/day, and 1.82 (95% CI, 0.98 to 3.38) for current smokers of 31 or more cigarettes/day (P for trend = 0.063). The respective multivariate-adjusted relative risks for high-frequency hearing impairment compared with never smokers were 1.70 (95% CI, 0.85 to 3.40), 1.82 (95% CI, 0.92 to 3.59), 2.00 (95% CI, 0.98 to 4.08), and 2.20 (95% CI, 1.09 to 4.42) (P for trend = 0.025). As the number of pack-years of exposure increased, the risk for high-frequency hearing impairment increased in a dose-dependent manner (P for trend = 0.011), but the risk for low-frequency hearing impairment did not (P for trend = 0.172). Our results indicate that cigarette smoking is highly associated with development of high-frequency hearing impairment in Japanese male office workers.