Yuanying Li

Incidence of metabolic syndrome according to combinations of lifestyle factors among middle-aged Japanese male workers

OBJECTIVE To examine a combination of healthy lifestyles on the risk of metabolic syndrome (MetS) to inform future interventions. METHODS A total of 1897 men aged 35-60 years participated in an annual health check-up in 2002 and 2005. MetS was defined by AHA/NCEP criteria. Logistic regression analyses were used to estimate age- and BMI-adjusted odds ratios (ORs) of MetS incidence for each healthy lifestyle (regular physical activity, adherence to healthy eating behaviors, not current smoking, and maintaining a stable weight since ones mid-twenties), separately (Model 1) and simultaneously (Model 2). A points system was developed to derive 3-year risk of MetS incidence by assigning a specific point to each healthy lifestyle. RESULTS MetS developed in 285 (15.0%) subjects after the follow-up. The ORs of MetS for each healthy lifestyle ranged from 0.42 to 0.64 (Model 2). Three-year risk of MetS incidence was predicted to differ from 1% to 60% according to the individual point total of the points system. The population-attributable fraction of MetS in subjects whose point total was not in the highest quartile was 71%. CONCLUSION Adherence to healthy lifestyles was associated with a lower risk of MetS among apparently healthy middle-aged Japanese male workers.

Breakfast Skipping is Positively Associated With Incidence of Type 2 Diabetes Mellitus: Evidence From the Aichi Workers’ Cohort Study

BACKGROUND Skipping breakfast has been suspected as a risk factor for type 2 diabetes (T2DM), but the associations are not entirely consistent across ethnicities or sexes, and the issue has not been adequately addressed in the Japanese population. METHODS We followed 4631 participants (3600 men and 1031 women) in a work-site cohort of participants aged 35-66 years in 2002 through 2011 for T2DM development. Frequency of eating breakfast was self-reported and was subsequently dichotomized to breakfast skippers, who eat breakfast 3-5 times/week or less, and to eaters. Cox proportional hazards models were used to adjust for potential confounding factors, including dietary factors, smoking and other lifestyles, body mass index (BMI), and fasting blood glucose (FBG) at baseline. RESULTS During 8.9 years of follow-up, 285 T2DM cases (231 men and 54 women) developed. Compared to participants who reported eating breakfast every day, maximally-adjusted hazard ratios and 95% confidence intervals (CI) of those with the frequency of almost every day and 3-5, 1-2, and 0 days/week were: 1.06 (95% CI, 0.73-1.53), 2.07 (95% CI, 1.20-3.56), 1.37 (95% CI, 0.82-2.29), and 2.12 (95% CI, 1.19-3.76), respectively. In a dichotomized analysis, breakfast skipping was positively associated with T2DM incidence (maximally-adjusted hazard ratio 1.73; 95% CI, 1.24-2.42). The positive associations were found in both men and women, current and non-current smokers, normal weight and overweight (BMI ≥ 25 kg/m(2)), and normal glycemic status and impaired fasting glycemic status (FBG 110 to <126 mg/dL) individuals at baseline (Ps for interaction all >0.05). CONCLUSIONS The present study in middle-aged Japanese men and women suggests that skipping breakfast may increase the risk of T2DM independent of lifestyles and baseline levels of BMI and FBG.Background Skipping breakfast has been suspected as a risk factor for type 2 diabetes (T2DM), but the associations are not entirely consistent across ethnicities or sexes, and the issue has not been adequately addressed in the Japanese population. Methods We followed 4631 participants (3600 men and 1031 women) in a work-site cohort of participants aged 35–66 years in 2002 through 2011 for T2DM development. Frequency of eating breakfast was self-reported and was subsequently dichotomized to breakfast skippers, who eat breakfast 3–5 times/week or less, and to eaters. Cox proportional hazards models were used to adjust for potential confounding factors, including dietary factors, smoking and other lifestyles, body mass index (BMI), and fasting blood glucose (FBG) at baseline. Results During 8.9 years of follow-up, 285 T2DM cases (231 men and 54 women) developed. Compared to participants who reported eating breakfast every day, maximally-adjusted hazard ratios and 95% confidence intervals (CI) of those with the frequency of almost every day and 3–5, 1–2, and 0 days/week were: 1.06 (95% CI, 0.73–1.53), 2.07 (95% CI, 1.20–3.56), 1.37 (95% CI, 0.82–2.29), and 2.12 (95% CI, 1.19–3.76), respectively. In a dichotomized analysis, breakfast skipping was positively associated with T2DM incidence (maximally-adjusted hazard ratio 1.73; 95% CI, 1.24–2.42). The positive associations were found in both men and women, current and non-current smokers, normal weight and overweight (BMI ≥25 kg/m2), and normal glycemic status and impaired fasting glycemic status (FBG 110 to <126 mg/dL) individuals at baseline (Ps for interaction all >0.05). Conclusions The present study in middle-aged Japanese men and women suggests that skipping breakfast may increase the risk of T2DM independent of lifestyles and baseline levels of BMI and FBG.

Inverse relationship of serum adiponectin concentration with type 2 diabetes mellitus incidence in middle-aged Japanese workers: six-year follow-up.

Background It was suggested that inflammation may mediate or modify biological effects of adiponectin. Few studies examined the association between circulating adiponectin levels and type 2 diabetes (T2DM) while controlling for variables related to inflammation. In addition, East Asians were reported to have lower adiponectin levels but higher diabetes prevalence at a given degree of obesity than Caucasians, raising some possibility that the adiponectin–diabetes association may differ by race. Therefore, we prospectively investigated the associations with a number of covariates including C‐reactive protein and smoking status in a cohort of Japanese workers aged 35–66 years.

Positive association between high-sensitivity C-reactive protein and incidence of type 2 diabetes mellitus in Japanese workers: 6-year follow-up

Elevated high‐sensitivity C‐reactive protein (hs‐CRP), a marker of low‐grade systemic inflammation, may be involved in the etiology of type 2 diabetes mellitus (T2DM). However, whether inflammation precedes development of T2DM independent of cigarette smoking and obesity remains to be confirmed.

Independent association of liver fat accumulation with insulin resistance.

BACKGROUND To examine the association of intrahepatic fat with homeostasis model assessment-insulin resistance (HOMA-IR), a marker of insulin resistance, in Japanese adults, and whether intrahepatic fat is associated with insulin resistance independent of waist circumference and other measures of obesity. METHODS Fifty-three individuals aged 37-69 were studied. Spectrum obtained using a 3-T magnetic resonance imager was analysed with LCModel to quantify intrahepatic fat. Blood levels of insulin, glucose and other biochemical markers were obtained after 8h or more fasting. Percent body fat was estimated by a bioelectrical impedance analyzer. HOMA-IR and intrahepatic fat content were log-transformed in the analysis. RESULTS We found a positive correlation between intrahepatic fat and HOMA-IR, which was independent of the anthropometric measures of obesity. In contrast, significant and positive correlations of body mass index, percent body fat, and waist circumference with HOMA-IR were largely explained by their associations with intrahepatic fat. Intrahepatic fat was positively associated with alanine transaminase and triglycerides even after adjustment for HOMA-IR. CONCLUSION Intrahepatic fat was associated with insulin resistance independent of age, sex, and measures of obesity in Japanese adults. Hypertriglyceridemia and liver injury may directly occur subsequent to intrahepatic fat accumulation.

Development of a Risk Equation for the Incidence of Coronary Artery Disease and Ischemic Stroke for Middle-Aged Japanese – Japan Public Health Center-Based Prospective Study –

BACKGROUND Global risk assessment for the prevention of atherosclerotic cardiovascular diseases helps guide the intensity of behavioral and pharmacological interventions. METHODSANDRESULTS The Japan Public Health Center-based prospective (JPHC) Study Cohort II (age range: 40-69 years at baseline in 1993-1994, n=15,672) was used to derive the risk equations for coronary artery disease (CAD) and ischemic stroke incidence via hazard regression. The model discrimination was evaluated by the area under the receiver-operating curve (AUC), and model goodness-of-fit by the Grønnesby-Borgan chi-squared statistic. During a mean of 16.4 years of follow up, 192 incident CAD cases and 552 ischemic stroke cases occurred. Variables selected for the CAD equation were age, sex, current smoking, systolic blood pressure, antihypertensive medication use, diabetes, and high-density lipoprotein cholesterol (HDLC) and non-HDLC. The same variables, except non-HDLC, were selected for the ischemic stroke equation. The equations discriminated incidence reasonably well (AUC: 0.81 for CAD, 0.78 for ischemic stroke). The AUC of the equation applied externally to Cohort I (n=11,598) was also good: 0.77 and 0.76 for CAD and ischemic stroke, respectively. Risk calculator application and color charts to visualize estimated risk according to the combinations of risk factors were prepared. CONCLUSIONS Risk equations were developed to estimate the 10-year probability of CAD and ischemic stroke in Japanese people, using variables that are routinely obtained. (Circ J 2016; 80: 1386-1395).

Serum γ-glutamyltransferase and Mortality due to Cardiovascular Disease in Japanese Men and Women

AIM Whether the association between serum γ-glutamyltransferase (γ-GTP) levels and total cardiovascular disease (CVD) mortality is independent of alcohol drinking in East Asian populations is not well known. We conducted a pooled analysis of Japanese men and women that enabled an analysis restricted to never-drinkers. METHODS A total of 15,987 men and 25,053 women aged 40-79 years, pooled from seven cohort studies throughout Japan, were followed-up to examine sex-specific relationship between serum γ-GTP levels and total CVD mortality. Cox regression model was used that was adjusted for age, smoking status, body mass index, and systolic blood pressure and serum triglyceride, total cholesterol, aspartate aminotransferase, and alanine aminotransferase levels. RESULTS During an average follow-up of 8.7 years, we documented 361 and 340 deaths from total CVD, 146 and 168 from stroke, and 101 and 53 from coronary heart disease (CHD) for men and women, respectively. Among the never-drinkers, hazard ratios (HRs) for mortality for one standard deviation of log-γ-GTP for men were 1.89 (1.00-3.58) for stroke, 1.04 (0.57-1.90) for CHD, and 1.43 (1.04-1.96) for total CVD. For women, HRs were 1.28 (1.06-1.54), 1.81 (1.34-2.44), and 1.30 (1.14-1.49), respectively. CONCLUSION γ-GTP may be a risk factor for total CVD mortality independent of alcohol drinking status in Japanese men and women.

Smoking and Diabetes: Is the Association Mediated by Adiponectin, Leptin, or C-reactive Protein?

Background Although the association between cigarette smoking and risk of type 2 diabetes is well established, its mechanisms are yet to be clarified. This study examined the possible mediating effects of adiponectin, leptin, and C-reactive protein (CRP) concentrations on the smoking-diabetes association. Methods Between 2002 and 2011, we followed 3338 Japanese workers, aged 35–66 years, who were enrolled in the second Aichi workers’ cohort study. We used multivariable-adjusted Cox regression models to determine the hazard ratios and respective 95% confidence intervals (CIs) of the association between smoking status and risk of diabetes. A multiple mediation model with bootstrapping was used to estimate the magnitude and the respective bias-corrected (BC) 95% CIs of the indirect effects of smoking on diabetes through the three biomarkers. Results Relative to never smokers, the risk of diabetes was significantly elevated in current (hazard ratio 1.75, 95% CI 1.25–2.46) and ex-smokers (hazard ratio 1.54, 95% CI 1.07–2.22). The indirect effects of smoking on diabetes through adiponectin levels were statistically significant among light (point estimate 0.033, BC 95% CI 0.005–0.082), moderate (point estimate 0.044, BC 95% CI 0.010–0.094), and heavy smokers (point estimate 0.054, BC 95% CI 0.013–0.113). In contrast, neither the indirect effects of smoking on diabetes through leptin nor CRP levels were significant, as the corresponding BC 95% CIs included zero. Conclusions In our analysis, adiponectin concentration appeared to partially mediate the effect of smoking on diabetes, while leptin and CRP levels did not.

Prospective study of seaweed consumption and thyroid cancer incidence in women: the Japan collaborative cohort study.

Excess intake of iodine is a suspected risk factor for thyroid cancer. Previous epidemiological research from Japan reported that daily intake of seaweed was associated with a four-fold higher risk in postmenopausal women, whereas others reported a null association. A major source of iodine intake in Japan is from edible seaweeds, and it is reported to be among the highest in the world. We examined the association between seaweed intake frequency and the risk of thyroid cancer in women in the Japan Collaborative Cohort Study followed from 1988 to 2009. Seaweed intake, together with other lifestyle-related information was collected using a self-administered questionnaire at baseline. Seaweed intake frequency was categorized as follows: 1–2 times/week or less, 3–4 times/week, and almost daily. Hazard ratios and the 95% confidence intervals of thyroid cancer incidence according to seaweed intake frequency were estimated using Cox proportional hazards regression. During 447 876 person-years of follow-up (n=35 687), 94 new cases of thyroid cancer were identified. The crude incidence rate was 20.9 per 100 000 person-years. The hazard ratio of thyroid cancer in women who consumed seaweed daily compared with women who ate it 1–2 times/week or less was 1.15 (95% confidence interval: 0.69–1.90, P for trend=0.59). Further analyses did not indicate any association between seaweed intake and the risk of thyroid cancer on statistically adjusting for potential confounding variables as well as on stratification by menopausal status. The present study did not find an association between seaweed intake and thyroid cancer incidence in premenopausal or in postmenopausal women.

Profile of Non-communicable Disease Risk Factors Among Young People in Palau

Background Although non-communicable diseases (NCDs) have become the predominant health problems of Palauan society, there have been no comprehensive data on NCD risk factors available to develop effective control strategies. Therefore, the first Palauan national STEPwise approach to risk factor Surveillance (STEPS) was completed in mid-2013 to provide information on its adult population aged 25 to 64 years. This study aims to obtain corresponding data from the younger adults aged 18 to 24 years, who remained to be surveyed. Methods We conducted an epidemiological study, targeting the 18- to 24-year-old age group. A survey station and a mobile team were established to recruit voluntary participants dwelling in Koror. A slightly modified WHO STEPS instrument was used, including a structured questionnaire for behavioral risk factors, physical measurements, and blood tests. Results A total of 356 young people were recruited during the survey. In both sexes, nearly half of the participants were overweight/obese. The prevalence of hypertension was higher in men than in women (17.6% vs 1.7%). Raised blood glucose and impaired fasting glucose were observed in 3.5% and 5.2% of the total participants, respectively. About 36% of the subjects were observed to have raised levels of total cholesterol. More than 70% of the young people were current tobacco users, in terms of all kinds of tobacco products. Conclusions The current survey, for the first time, revealed a high prevalence of NCD risk factors, especially overweight/obesity and tobacco use, among young people in Palau. This indicates that swift measures against NCDs are required even in this young age group.