Changes in activities of daily living, physical fitness, and depressive symptoms after six-month periodic well-rounded exercise programs for older adults living in nursing homes or special nursing facilities

A 6-month, twice weekly, well-rounded exercise program (47 sessions in total) comprised of a combination of aerobic, resistance and flexibility training was provided for institutionalized older adults aged 60 to 93. We analyzed the data of 18 older adults who could stand and had attended more than 10% of the classes (mean participation rate: 54%) to examine changes in activities of daily living (ADL), physical fitness tests and depressive moods. The mean (+/- standard deviation, range) age of the participants was 71.3 (+/- 15.6, 60-93) in men and 85.9 (+/- 5.8, 72-93) in women. Significant improvement in ADL of the hand manipulation domain and borderline significant improvement in ADL of the mobility domain were observed (McNemar test p = 0.011 and 0.072, respectively). A 6-minute walk distance increased significantly from 151.6 m to 236.6 m (p = 0.01, paired t-test), and the result of the Soda Pop test, which tests hand-eye coordination, also improved significantly from 35.2 sec to 25.3 sec (p = 0.01, paired t-test). These findings suggest that such a program could be effective in improving the ADL and physical fitness of the elderly.

Effect of the interaction between mental stress and eating pattern on body mass index gain in healthy Japanese male workers

Background

The effect of the interaction between long-term mental stress and eating habits on weight gain has not been confirmed in humans.

Methods

A population of 1080 healthy Japanese male local government employees without lifestyle-related diseases were studied. Height and weight were measured and perception of mental stress and the frequency of eating to satiety, drinking, smoking, and exercise were surveyed by means of a questionnaire in both 1997 and 2002. Exposure patterns during this 5-year period were classified as low or high. Information on daily food and energy intake was collected in 2002. The effect of the interaction between stress and the frequency of eating to satiety on change in BMI (ΔBMI) during this 5-year period was examined by 2-way analysis of variance (ANOVA) and covariance (ANCOVA) adjusted for age, BMI at baseline, and other lifestyle habits. The association between satiation eating and ΔBMI was compared between participants with high and low levels of stress.

Results

Stress and satiation eating were not significantly mutually correlated. Two-way ANCOVA showed a significant interaction (F = 4.90, P = 0.03) between mental stress and satiation eating. Among participants with a high level of stress, BMI gain was significantly larger in those who ate to satiety than in those who ate moderately, when ΔBMI was unadjusted or adjusted for covariates (adjusted mean [SE]: 0.34 ± 0.06 kg/m² vs. 0.12 ± 0.07 kg/m², P = 0.002). Among participants with a low level of stress no such difference was observed. These results were unchanged after further adjustment for energy intake in 2002.

Conclusion

In this population, eating pattern interacted with long-term mental stress to produce a larger body mass gain in satiation eaters than in moderate eaters among participants with a high level of stress, independent of energy intake or other lifestyle habits.

Uric acid and left ventricular hypertrophy in Japanese men

BACKGROUND

Experimental studies have reported that allopurinol protects hypertensive rats from left ventricular hypertrophy (LVH) with negligible effects on blood pressure (BP). Uric acid (UA) was thought to induce cardiomyocyte growth and interstitial fibrosis of the heart, partly via activation of the renin-angiotensin system. In the present study, the relationship between serum UA levels and electrocardiographically-diagnosed LVH (ECG-LVH) was examined in Japanese men not taking medication for hypertension (HTN), which could confound the association.

METHODS AND RESULTS

A total of 3,305 male workers aged 35-66 years (mean age+/-SD, 48.0+/-7.1) were studied. LVH was defined as meeting the ECG criteria (ie, Sokolow-Lyon voltage and/or Cornell voltage QRS duration product). Subjects were divided into 3 groups by tertile of serum UA level. The highest tertile (UA range 0.39-0.65 mmol/L or 6.6-11.0 mg/dl) had a significantly increased prevalence of LVH compared with the lowest tertile independent of age, body mass index, serum creatinine level, HTN, diabetes and hyperlipidemia (odds ratio 1.58, 95% confidence interval 1.23-2.02, P<0.001). Similar results were obtained in both the normal and high BP subgroups.

CONCLUSIONS

UA concentration independently and positively associated with ECG-LVH in Japanese men.

Multilevel analyses of effects of variation in body mass index on serum lipid concentrations in middle-aged Japanese men

For the effective use of the annual workplace health checkup data, we tried to perform multilevel analyses to explore whether the year-to-year weight variation causes any concurrent effects on the lipid profiles among middle-aged Japanese workers. Subjects were 1939 healthy male workers 40-59 in age from whom serial data of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) were collected during health checkups conducted in the years 1997-2000. The effects of body mass index (BMI) on serum concentrations of those lipids were investigated by statistical analysis with multilevel modeling to distinguish multiple levels of information with individual repeated measurements within individuals. A significant increase of TC and TG, and decrease of HDL-C with BMI increase were confirmed. Subanalyses according to both the baseline BMI status (< 25 kg/m2 or > or =25 kg/m2) and smoking status (never, former, or current) yielded the same BMI-dependent changes of lipid profiles, but obese never smokers failed to show significant effects of BMI on HDL-C concentrations. Multilevel analyses of annual health checkup data linked at individual levels indicated that year-to-year weight variation, though usually in a much narrower range than the between-individual variation, had a strong impact on the corresponding changes of serum concentrations of TC, HDL-C, and TG. This result supports the public health significance of intervention into weight control to prevent the development of atherogenic risks among a healthy workplace population.

[Physical and mental health characteristics of female caregivers]

OBJECTIVE

In Japan, research into physical conditions or illnesses of female caregivers focusing on biological markers in biological materials such as blood and urine has been limited. Therefore, the present study was conducted to clarify the physical and mental characteristics of female caregivers in comparison with the general population, using biological markers and self-answered questionnaires.

METHODS

The subjects were 161 female in-home primary caregivers for persons requiring care at level 3 or more or less than 3 if suffering from dementia (caregiver group). The control group consisted of females matched 1 : 1 in the same decade of life who received medical checkups in K city. The survey period was from December 2005 to April 2007. The methods were self-answered questionnaires, including lifestyle, caregiving conditions, the Pittsburgh Sleep Quality Index (PSQI) and frequency of taking food, and common parameters for lifestyle diseases using blood and urine and blood pressure, taken by trained investigators at the subjects homes.

RESULTS

Average age was 62.8 +/- 11.9 years in the caregiver group and 63.2 +/- 12.4 years in the control group. 46.0% had 5 or more years experience in caregiving and 8.7% had less than 1 year. The required care level most common was 5 at 33.8%, with levels 3 and 4 the next most common. 46.0% of the caregiver group had hypertension, significantly higher than the 34.2% in the control group. The prevalence of glucose intolerance and hypo-HDL-cholesterolemia was also high in the caregiver group, but without significant difference. The caregiver group had lower HDL-cholesterol values than the control group. In lifestyle, the two groups differed in exercise, PSQI, proportion of energy from carbohydrates and estimated 24-hour excretion of sodium (Na) in urine. In particular, it was clear that Na was undesirable for caregiver,s even using urine samples for examination. Although more in the caregiver group described themselves as unhealthy, fewer of them received annual health checkups than in the control group. More in the caregiver group felt stress about their health or aging or depression, with few opportunities for diversion.

CONCLUSIONS

Hypertension, the most important risk factor for brain and cardiovascular disease, is significantly high in caregivers, suggesting the need for preventive measures. Similar findigns were also obtained with other biological markers and more in the caregiver group felt stress about their health or aging or depression, pointing to a nee for health support.

Association between low birth weight and elevated white blood cell count in adulthood within a Japanese population

BACKGROUND

Epidemiological studies have demonstrated the association between low birth weight and increased adulthood risk for cardiovascular and metabolic diseases. However, the precise mechanism underlying the association remains poorly understood. We investigated the association between birth weight and adult white blood cell (WBC) count in a Japanese population.

METHODS AND RESULTS

The subjects were 779 men and 209 women aged 35-64 years. The mean WBC count was 5,283 /microl (SD: 1,326). Birth weight was divided to 6 categories: <2,500, 2,500-<2,800, 2,800-<3,000, 3,000-<3,200, 3,200-<3,500, and >3,500 g. Estimated WBC counts were 5,729, 5,341, 5,301, 5,212, 5,013 and 5,372 for the subjects with birth weights of the above respective categories (p=0.015, trend p=0.016) by one-way analysis of covariance after adjustments for sex, age, height, body mass index (BMI), lifestyles, and chronic diseases. This association was pronounced among the subjects with a BMI <25.0 kg/m2 rather than those with a higher BMI.

CONCLUSIONS

These findings support the idea that part of the association of low birth weight with elevated risk for vascular and metabolic diseases in later life could be mediated by an inflammatory pathway.

Low leptin but high insulin resistance of smokers in Japanese men

AIMS

To investigate the association between smoking and leptin, and to discuss their influence on diabetes in a large-scale study of Japanese men.

METHODS

A cross-sectional study was carried out in 2002. The subjects were 2836 men aged 35-66. Smoking history was investigated in a self-administered questionnaire. Blood leptin, glucose and insulin were measured.

RESULTS

Significant differences in leptin levels and homeostasis model assessment of insulin resistance (HOMA-IR) related to smoking status were observed (P=0.001 and P=0.008, respectively). The multivariate-adjusted geometric means of leptin in current, past and never smokers were 3.88, 4.08 and 4.12 ng/ml, respectively, while the means of HOMA-IR were 1.64, 1.61 and 1.49, respectively. The age-, body mass index-, and other lifestyle-adjusted prevalences of diabetes in current and never smokers were 9.2 and 4.7%, respectively. That of current smokers was significantly higher than in never smokers (P<0.001). The dose-dependent association found between the intensity of smoking and leptin levels in current smokers was statistically significant (P=0.030).

CONCLUSIONS

The present finding may explain in part an association among smoking, leptin levels and diabetes. Smoking is one of the important modifiable risk factors for the prevention of diabetes.

Having more healthy practice was associated with low white blood cell counts in middle-aged Japanese male and female workers

White blood cell (WBC) count is well known to be an independent risk marker for cardiovascular disease. The aim of this study is to examine the relationships of WBC counts to seven health practices including obesity, eating habits, smoking, alcohol intake, sleeping, physical activity, and perceived mental stress, and then clustering the relevant healthy practices. The subjects were 1,492 male and 316 female Japanese workers aged 40 yr and over in 2002. Each of seven health practices from a self-administered questionnaire was categorized as a 'healthy' or 'unhealthy' practice, and WBC counts from fasting blood samples were determined by automated particle counters. The means of age and WBC counts were 49.5 yr and 5,375 cells/microl in men, and 48.6 yr and 4,890 cells/microl in women, respectively. After multivariate adjustments for all health practices and age, the estimated WBC counts were significantly lower in normal weight subjects and never or former smokers (p<0.01). Age-adjusted WBC counts decreased significantly by 204.9+/-23.7 cells/microl (means+/-SE) and 117.6+/-53.2 cells/microl for each increase in one healthy practice (p<0.05), respectively, suggesting that cultivating healthier practices would lead to lower WBC counts. This study recommends modifying unhealthy practice one by one and maintaining healthy practices as an effective strategy for the prevention of atherosclerotic diseases, in addition, to quit smoking or abstain from heavy smoking especially in men is important to prevent the low-grade inflammation.

Development and validity of the Japanese version of body shape silhouette: relationship between self-rating silhouette and measured body mass index

We devised new body shape silhouettes to more accurately reflect Japanese body sizes. Our aim was to assess the association between measured body mass index (BMI) and body size through self-selection of nine figure scales. This study was comprised of 4808 men and 1093 women aged 35-71 years. Subjects were asked to identify the silhouettes that most accurately represent their current body size. BMI was calculated from measured height and weight based on annual health checkups. Spearman's correlation coefficients between silhouette ratings and BMI were 0.73 in men and 0.80 in women. Moreover, mean BMIs increased in value with increasing silhouette numbers in both genders (trend p < 0.01 for both). Simple linear regression models predicting BMI based on silhouette ratings showed a good fit, with silhouette self-selection statistically explaining 54.0% of BMI variance in men and 62.5% in women. Receiver operating curves showed that areas under the characteristics curves were higher than 0.8 for obesity and thinness in both genders. These findings suggest that our scale is a promising tool for examining body size and image among Japanese adults.

Contribution of adipocytokines to low-grade inflammatory state as expressed by circulating C-reactive protein in Japanese men: comparison of leptin and adiponectin

BACKGROUND

Circulating C-reactive protein (CRP) is a marker of inflammation and is associated with the incidence of cardiovascular events. Although it has been known that adiponectin protects, whereas leptin accelerates, the development of atherosclerotic diseases, the comparative strength of their reciprocal effects on circulating CRP remains unclear.

METHODS

We studied a population of 2049 Japanese men aged 35 to 66. For all subjects, multiple regression analysis performed with log-transformed CRP concentration as the dependent variable, and with log-transformed leptin, log-transformed adiponectin, age, BMI, smoking status, and components of metabolic syndrome as independent variables.

RESULTS

Both leptin (positively) and adiponectin (negatively) were significantly and independently associated with CRP concentration. The absolute value of the standardized regression coefficient (st-beta) of leptin (st-beta=0.201) was higher than that of adiponectin (st-beta=-0.082). After subjects were stratified by current BMI level, both of the adipocytokines were significantly associated with CRP concentration among subjects with BMI <25 kg/m(2), whereas only leptin was significantly associated with CRP concentration among subjects with BMI >=25 kg/m(2).

CONCLUSIONS

Both leptin and adiponectin were independently associated with CRP concentration. Leptin was more strongly related to CRP levels than adiponectin was, especially among obese subjects.

Active smoking, passive smoking, and breast cancer risk: findings from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk

BACKGROUND

Evidence is lacking regarding the relationship between cigarette smoking and breast cancer in Japanese women. We examined the association between breast cancer incidence and active and passive smoking in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk.

METHODS

Our study comprised 34,401 women aged 40-79 years who had not been diagnosed previously with breast cancer and who provided information on smoking status at baseline (1988-1990). The subjects were followed from enrollment until December 31, 2001. Cox proportional-hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between breast cancer incidence and tobacco smoke.

RESULTS

During 271,412 person-years of follow-up, we identified 208 incident cases of breast cancer. Active smoking did not increase the risk of breast cancer, with a HR for current smokers of 0.67 (95% CI: 0.32-1.38). Furthermore, an increased risk of breast cancer was not observed in current smokers who smoked a greater number of cigarettes each day. Overall, passive smoking at home or in public spaces was also not associated with an increased risk of breast cancer among nonsmokers. Women who reported passive smoking during childhood had a statistically insignificant increase in risk (HR: 1.24; 95% CI: 0.84-1.85), compared with those who had not been exposed during this time.

CONCLUSION

Smoking may not be associated with an increased risk of breast cancer in this cohort of Japanese women.

Eating fast leads to insulin resistance: findings in middle-aged Japanese men and women

OBJECTIVE

To examine relationships between speed of eating and insulin resistance.

METHODS

Cross-sectional study of 2704 male (mean age and BMI: 48.2 y and 23.3 kg/m(2)) and 761 female (46.3 y and 21.8 kg/m(2)) non-diabetic Japanese civil servants, 75% clerical, and 25% manual laborers, using a two-part questionnaire on life-style factors and diet history with self-assessment of categorical speed of eating and energy intake over a 1-month period. We measured BMI, blood glucose and insulin concentrations and calculated insulin resistance using the homeostasis model assessment of insulin resistance: (HOMA-IR).

RESULTS

BMI correlated with eating rate in both sexes, and with daily energy intake in men. Multiple regression analysis of log HOMA-IR by categorical speed of eating, adjusting for age, energy intake and lifestyle factors showed a statistically significant gradual increase in HOMA-IR with increases in relative eating rate in men (p<0.001, for trend) and in women (p<0.01). Adjusting for BMI, this positive relationship appeared only in men (p=0.03).

CONCLUSIONS

Our results suggest that eating fast is independently associated with insulin resistance in middle-aged Japanese men and women.

Smoking status and adiponectin in healthy Japanese men and women

BACKGROUND

Recent studies promisingly indicate that adiponectin plays an important and fundamental role in the development and progression of metabolic and atherosclerosis disorders. Smoking is known as one of the most important risk factors of atherosclerosis, and its relation with metabolic disorders has also been reported. We therefore investigated the association between cigarette smoking and adiponectin concentration in a large sample of Japanese men and women.

METHOD

The cross-sectional study was carried out in 2002. The subjects were 3260 men and 953 women local government workers aged 35 to 59 in Japan. Lifestyle-related variables including detailed smoking history were inquired in a self-administered questionnaire.

RESULTS

Significant differences in adiponectin levels related to smoking status were observed in both men and women (p=0.001). A dose-dependent association was found between the intensity of smoking and adiponectin levels in current smokers, and was statistically significant in men (p for trend=0.006 in the multivariate-adjusted model). Men who quit smoking for more than 20 years and women for more than 10 years had an adiponectin concentration similar to that observed in non-smokers.

CONCLUSION

We not only revealed that current smoking habit was associated with low adiponectin level but also found a dose-dependent association between smoking intensity and adiponectin level in current smokers. The present finding may provide further evidence of the importance of a causal relationship between smoking status and adiponectin concentrations.

Gender and age differences in lifestyle factors related to hypertension in middle-aged civil service employees

The aim of this study is to identify lifestyle factors related to hypertension in man and woman workers, and to investigate age and gender differences in the relationships of the factors. From 6,000 civil service employees (4,937 men and 1,063 women) aged 40-69 years, information on lifestyle-related factors such as stress, exercise habits, preference for salty taste, alcohol drinking and smoking habits, and body mass index, as well as age and family history of hypertension was obtained through self-administered questionnaires in 1997. Hypertension was defined as either a systolic blood pressure > or = 140 mmHg, a diastolic blood pressure > or = 90 mmHg, or undergoing treatment for hypertension, and was present by 37.0% in men and 19.6% in women. Only body mass index was a significant lifestyle-related risk factor common to both genders with an odds ratio and its 95% confidence interval in parentheses of 2.2 (2.0-2.5) for men and 3.2 (2.3-4.6) for women. Men and women who preferred salty taste showed multivariate adjusted odds ratios of 0.9 (0.8-1.1) and 1.5 (1.1-2.2) for hypertension, respectively. In the stratified subanalysis, women aged 50 years and over had a significant odds ratio of 2.7 (1.5-4.9), whereas women aged 40-49 years and men of all age classes failed to show significant relationships. Salt intake was suggested to be a key factor for hypertension particularly for women after menopause.

Risk factors for first acute myocardial infarction attack assessed by cardiovascular disease registry data in Aichi Prefecture

Recently, in Western countries, metabolic syndrome as well as such classical risk factors as hypertension and smoking has been considered to be closely associated with the occurrence of acute myocardial infarction (AMI). Therefore, we conducted a case-control study to investigate how the co-morbidity of obesity or thinness with hypertension, hyperlipidemia and diabetes mellitus would affect AMI occurrence among Japanese aged 30 to 69. Cases were comprised of 788 patients (590 men and 198 women) registered in the "Aichi Prefecture Cardiovascular Disease Registry Program" during hospitalization due to their first AMI attack. Controls were 2,300 randomly sampled inhabitants (1,142 men and 1,158 women) who responded to the questionnaire survey on lifestyle. We decided BMI < 18.5 as thin, 18.5 < or = BMI < 25.0 as normal, and BMI > or = 25.0 as obese, then divided subjects into six groups according to the presence or absence of histories of the above-mentioned three diseases in connection with their physique. In both sexes, multivariately adjusted odds ratios of first AMI attacks were much higher in groups with such histories (men, 4.14 to approximately 5.07; women, 5.62 to approximately 15.24) than in those without them (men, 0.90 to approximately 1.13; women, 1.54 to approximately 3.03) regardless of physique. Only in women, obesity uncombined with histories was significantly associated with AMI occurrence and not obesity but thinness intensified the association between histories and AMI. Among the six groups, population attributable risk percent was highest in the normal physique group with histories. It was suggested that persons with disease histories should be carefully treated irrespective of the presence or absence of obesity.

Consumption of soy foods and the risk of breast cancer: findings from the Japan Collaborative Cohort (JACC) Study

OBJECTIVE

The association between a lower incidence of breast cancer within the Asian population and the consumption of a diet high in soy has recently been the subject of much attention. To examine whether soy foods really have protective effects against breast cancer and how their influence on breast cancer is modified according to menopausal status, we conducted a population-based, prospective cohort study in Japan.

METHODS

We analyzed the data from the Japan Collaborative Cohort (JACC) Study. From 1988 to 1990, 30,454 women aged 40-79 years, completed a questionnaire on diet and other lifestyle features. Hazard ratios (HRs) were computed to examine the association between soy intake and the risk of breast cancer.

RESULTS

During the mean follow-up of 7.6 years, 145 cases of breast cancer were documented. We found no significant association between the risk of breast cancer and consumption of tofu, boiled beans, and miso soup; the multivariate HRs (95% CI) in the highest category of consumption were 1.14 (0.74-1.77), 0.77 (0.47-1.27) and 1.01 (0.65-1.56), respectively. Only among postmenopausal women, we found no significant associations between soy foods and the risk of breast cancer.

CONCLUSIONS

This prospective study suggests that consumption of soy food has no protective effects against breast cancer. Further large-scale investigations eliciting genetic factors may clarify different roles of various soybean-ingredient foods on the risk of breast cancer.

Dietary fiber and risk of colorectal cancer in the Japan collaborative cohort study

To examine the association of dietary fiber with the risk of colorectal cancer in a population with a high incidence of cancer and a low fiber intake, we analyzed the data from the Japan Collaborative Cohort Study. From 1988 to 1990, 43,115 men and women aged 40 to 79 years completed a questionnaire on dietary and other factors. Intake of dietary fiber was estimated using a food frequency questionnaire. Rate ratios (RR) were computed by fitting proportional hazards models. During the mean follow-up of 7.6 years, 443 colorectal cancer cases were recorded. In all participants, we found a decreasing trend in risk of colorectal cancer with increasing intake of total dietary fiber; the multivariate-adjusted RRs across quartiles were 1.00, 0.96 [95% confidence interval (95% CI), 0.72-1.27], 0.72 (0.53-0.99), and 0.73 (0.51-1.03; P(trend) = 0.028). This trend was exclusively detected for colon cancer: the corresponding RRs were 1.00, 0.90 (95% CI, 0.64-1.26), 0.56 (0.38-0.83), and 0.58 (0.38-0.88; P(trend) = 0.002). The decrease in RRs with increasing intake of dietary fiber was larger in men than in women. No material differences appeared in the strength of associations with the risk between water-soluble and insoluble dietary fiber. For food sources of fiber, bean fiber intake was somewhat inversely correlated with colorectal cancer risk. This prospective study supported potential protective effects of dietary fiber against colorectal cancer, mainly against colon cancer. The role of dietary fiber in the prevention of colorectal cancer seems to remain inconsistent, and further investigations in various populations are warranted. (

Results of the Health Assessment Questionnaire for Japanese patients with systemic sclerosis--measuring functional impairment in systemic sclerosis versus other connective tissue diseases

OBJECTIVE

To evaluate the physical functional impairment in patients with systemic sclerosis (SSc) using the Health Assessment Questionnaire (HAQ) and to estimate the correlation of HAQ scores with the severity of SSc.

METHODS

One hundred and twenty-four outpatients with connective tissue disease, including 50 patients with SSc, were evaluated using the HAQ. Twelve patients were classified as having diffuse cutaneous SSc (dSSc) and 38 limited cutaneous SSc (lSSc). The severity classification and the guidelines for treatment (2004) were applied to Japanese SSc patients in order to evaluate the relationship between HAQ scores and disease activity in patients with multiple organ involvement.

RESULTS

In dSSc the HAQ category scores for eating, walking, grip, activity and the HAQ-disability index (HAQ-DI) showed the greatest deficits in all disease groups. The severity of disease activity correlated significantly with the scores for walking, reach, and the HAQ-DI. The severity of joint, heart, and pulmonary hypertension were correlated independently with the HAQ-DI score by multiple linear regression analysis.

CONCLUSION

Patients with dSSc suffer greater functional impairment than patients with other connective tissue diseases, and improvements in hand use and walking represent very important targets for both drug development and rehabilitation. As improvement in organ involvement (joints, heart as well as pulmonary hypertension) can lead to reduced functional impairment, they constitute an important target for therapy in SSc.

Further inflammatory information on metabolic syndrome by adiponectin evaluation

BACKGROUND

Despite a close association of adiponectin with metabolic syndrome (MetS), its usefulness as an additional MetS factor has not been well investigated.

METHODS

We studied 2327 apparently healthy Japanese male office workers aged 35 to 66 years old and investigated cross-sectionally whether categorization by serum adiponectin distinguished participants' levels of high-sensitivity C-reactive protein (CRP) beyond the conventional MetS.

RESULTS

In a linear regression analysis, adiponectin was associated with CRP independently of all MetS factors (beta=-0.192, P<0.001). Furthermore, a graded decrease in CRP level was observed with elevation of adiponectin in every stratum characterized by the presence or absence of each MetS component (trend P<0.05 in all strata except those of decreased high-density lipoprotein cholesterol or hyperglycemia). Similarly, geometric means of CRP levels (mg/l) decreased as adiponectin increased from the lowest to the highest tertile in all strata classified by the number of MetS components, though a P value did not reach statistical significance in those with 3 MetS components (the stratum of 0 MetS component: 0.41 [95% confidence interval, 0.34-0.49], 0.32 [0.28-0.37] and 0.26 [0.23-0.30], trend P<0.001; 1 component: 0.45 [0.39-0.52], 0.38 [0.34-0.43], and 0.32 [0.28-0.36], trend P<0.001; 2 components: 0.58 [0.50-0.67], 0.51 [0.44-0.60], and 0.46 [0.38-0.55], trend P=0.043; 3 components: 0.80 [0.66-0.96], 0.69 [0.55-0.87], and 0.58 [0.39-0.85], trend P=0.139).

CONCLUSIONS

Adiponectin evaluation provides additional inflammatory information on conventional MetS, supporting the potential of hypoadiponectinemia as an additional MetS component for identifying high-risk individuals for cardiovascular disease.

Adiponectin level and left ventricular hypertrophy in Japanese men

A recent study has demonstrated that adiponectin inhibited hypertrophic signaling in the myocardium of mice, implying that a decrease in the blood adiponectin level could cause cardiac muscle hypertrophy. We hypothesized that a relationship might exist between the serum adiponectin level and electrocardiographically diagnosed left ventricular hypertrophy (ECG-LVH), and we examined this hypothesis by epidemiological study of 2839 Japanese male workers who were not taking medications for hypertension. ECG-LVH was defined as meeting Sokolow-Lyon voltage criteria and/or Cornell voltage-duration product. The subjects were categorized by tertiles of serum adiponectin level, and a multivariate logistic regression analysis was conducted relating left ventricular hypertrophy to adiponectin tertiles adjusting for potential confounding factors. Prevalence of ECG-LVH in the studied sample was 16.7%. Adiponectin ranged from 1.0 to 5.0 microg/mL in the lowest category and from 7.4 to 30.6 microg/mL in the highest. Compared with subjects in the highest adiponectin category, those in the lowest one had a significantly higher prevalence of ECG-LVH independent of age, body mass index, and systolic blood pressure with an odds ratio of 1.50 and a 95% CI of 1.16 to 1.94. Further adjustment for high-density lipoprotein cholesterol, triglyceride, and insulin resistance did not change the association (odds ratio: 1.68; 95% CI: 1.28 to 2.21; P<0.001). Similar results were obtained when different criteria for ECG-LVH were used or when subjects were stratified by blood pressure or body mass index. Adiponectin concentration was inversely and independently associated with ECG-LVH in Japanese men.

Psychological factors and insomnia among male civil servants in Japan

OBJECTIVE

This study aims at assessing the relative impact of psychological factors on insomnia among daytime workers.

BACKGROUND

Insomnia affects 5-45% of non-shift workers, making it a serious public health concern.

METHODS

The study population was 3435 male civil servants aged 35 years and over. A self-administered questionnaire survey was conducted in 2002. Annual health examination data compiled in the same year were also obtained. Insomnia was assessed in three domains: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and poor quality of sleep (PQS). Association of each factor with insomnia was examined by age-adjusted logistic regression models. Factors significantly associated with insomnia in age-adjusted analyses were entered in the stepwise logistic regression models to test the relative impact of each factor.

RESULTS

Prevalence of insomnia was 12.3% (DIS), 20.4% (DMS), and 32% (PQS). In stepwise logistic models, high perceived stress was associated with all types of insomnia with odds ratios (95% confidence interval) of 2.27 (1.58-3.26), 2.15 (1.57-2.95), and 2.96 (2.19-3.99), for DIS, DMS, and PQS, respectively. Poor psychological well-being or not having confidants was also associated with insomnia. Somatic conditions such as illnesses or history of hospitalization were related to DIS and DMS.

CONCLUSIONS

Psychological factors were strongly associated with DIS and PQS after controlling for possible confounders. In dealing with insomnia, such factors must not be neglected.