Studies on Gas Seepage Characteristics in Different Stress Zones of Bottom Coal in Steeply Inclined and Extra-Thick Coal Seams under Mining Action.

The gas released from the bottom coal of the horizontal slicing mining face in steeply inclined and extra-thick coal seams seriously threatens the safety of the upper slicing mining face. To explore the seepage characteristics of bottom coal gas, the coal deformation and gas permeability evolution law of four coal samples in different stress zones of bottom coal in the working face were analyzed through true triaxial fluid-solid coupling seepage experiments. At the same time, the seepage capacity of bottom coal gas was partitioned according to the field test. The results show the following: (1) The gas permeability of the bottom coal stress concentration zone first decreased and then increased with axial pressure loading and confining pressure unloading. The gas permeability of the bottom coal stress relief zone increased rapidly with decreasing axial pressure and confining pressure. The gas permeability of the bottom coal stress recovery zone gradually decreased with the cyclic loading and unloading of axial pressure and tended to be stabilized. (2) The evolution law of gas permeability in the bottom coal was closely related to the damage and deformation of coal. (3) From the original stress zone to the stress recovery zone, the gas seepage capacity of bottom coal can be divided into four zones, namely, the original seepage zone, the seepage reduction zone, the seepage sharp increase zone, and the seepage reduction zone. The gas seepage capacity in the stress concentration zone was more substantial than that of the stress recovery zone. The results of this study are of great significance for strengthening the dynamic disaster prevention and control of bottom coal gas in the horizontal slicing mining face of steeply inclined and extra-thick coal seams.

Change Law of Lower Limit of Gas Explosion at Ultra-High Temperatures.

During coal seam mining, a large amount of low-concentration mine gas will be produced, and it is the main utilization way to pass it into a thermal storage oxidation device to obtain heat energy. The thermal storage oxidation process is carried out in an ultra-high temperature environment. The excessive gas concentration not only reduces the production efficiency but also presents an explosion hazard. To solve the abovementioned problems, the lower explosion limit of a low-concentration gas at ultra-high temperatures (900-1200 °C) was studied through a self-developed high-temperature explosion experimental device. Fluent software was used to simulate the reaction of a low-concentration gas in a high-temperature environment, and the experimental results were verified according to the maximum explosion pressure. Through analysis and discussion, the following are found: (1) the relationship between the instantaneous explosion pressure of the low-concentration gas and the gas concentration as well as the relationship between the maximum explosion pressure near the lower explosion limit and the gas concentration are in accordance with the Boltzmann function. (2) When the temperature rises from 900 to 1200 °C, the lower limit of gas explosion obtained from experiments is reduced from 2.33 to 1.36%. (3) The lower limit of gas explosion decreases with increasing temperature at ultra-high temperatures and the downward trend slows down, this is similar to the change rule of the lower limit of gas explosion at temperatures below 200 °C. These findings have certain practical significance for improving the utilization efficiency of the low-concentration gas in heat storage oxidation.

Associations of Plasma Amino Acid and Acylcarnitine Profiles with Incident Reduced Glomerular Filtration Rate.

BACKGROUND AND OBJECTIVES: Metabolomics is instrumental in identifying novel biomarkers of kidney function to aid in the prevention and management of CKD. However, data linking the metabolome to incident eGFR are sparse, particularly in Asian populations with different genetic backgrounds and environmental exposures. Therefore, we aimed to investigate the associations of amino acid and acylcarnitine profiles with change in eGFR in a Chinese cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study included 1765 community-living Chinese adults aged 50-70 years with baseline eGFR≥60 ml/min per 1.73 m2. At baseline, 22 amino acids and 34 acylcarnitines in plasma were quantified by gas or liquid chromatography coupled with mass spectrometry. Annual rate of change in eGFR was calculated, and incident eGFR decline was defined as eGFR<60 ml/min per 1.73 m2 by the end of 6 years of follow-up. RESULTS: The mean (SD) unadjusted annual change in eGFR was 2.2±2.0 ml/min per 1.73 m2 and the incidence of reduced eGFR was 16%. After Bonferroni correction, 13 of 56 metabolites were significantly associated with annual eGFR change. After multivariable adjustment of baseline covariates, including baseline eGFR, seven of the 13 metabolites, including cysteine, long-chain acylcarnitines (C14:1OH, C18, C18:2, and C20:4), and other acylcarnitines (C3DC and C10), were significantly associated with incident reduced eGFR (relative risks ranged from 1.16 to 1.25 per SD increment of metabolites; P<3.8E-03 after Bonferroni correction of multiple testing of the 13 metabolites). Moreover, principal component analysis identified two factors, consisting of cysteine and long-chain acylcarnitines, respectively, that were associated with incident reduced eGFR. CONCLUSIONS: Elevated plasma levels of cysteine and a panel of acylcarnitines were associated with a higher incidence of reduced eGFR in Chinese adults, independent of baseline eGFR and other conventional risk factors.

Age at menarche and age at natural menopause in East Asian women: a genome-wide association study.

Age at menarche (AM) and age at natural menopause (ANM) are complex traits with a high heritability. Abnormal timing of menarche or menopause is associated with a reduced span of fertility and risk for several age-related diseases including breast, endometrial and ovarian cancer, cardiovascular disease, and osteoporosis. To identify novel genetic loci for AM or ANM in East Asian women and to replicate previously identified loci primarily in women of European ancestry by genome-wide association studies (GWASs), we conducted a two-stage GWAS. Stage I aimed to discover promising novel AM and ANM loci using GWAS data of 8073 women from Shanghai, China. The Stage II replication study used the data from another Chinese GWAS (n = 1230 for AM and n = 1458 for ANM), a Korean GWAS (n = 4215 for AM and n = 1739 for ANM), and de novo genotyping of 2877 additional Chinese women. Previous GWAS-identified loci for AM and ANM were also evaluated. We identified two suggestive menarcheal age loci tagged by rs79195475 at 10q21.3 (beta = -0.118 years, P = 3.4 × 10-6) and rs1023935 at 4p15.1 (beta = -0.145 years, P = 4.9 × 10-6) and one menopausal age locus tagged by rs3818134 at 22q12.2 (beta = -0.276 years, P = 8.8 × 10-6). These suggestive loci warrant a further validation in independent populations. Although limited by low statistical power, we replicated 19 of the 98 menarche loci and 5 of the 20 menopause loci previously identified in women of European ancestry in East Asian women, suggesting a shared genetic architecture for these two traits across populations.

Nickel exposure and prevalent albuminuria and ß2-microglobulinuria: evidence from a population-based study.

BACKGROUND: High exposure to nickel could induce renal dysfunction in rodents and occupational workers. However, little is known about the effects of non-occupational exposure to nickel on renal health in the general population. We aimed to examine the associations of urinary nickel concentrations with albuminuria and ß2-microglobulinuria in Chinese adults. METHODS: 2115 non-institutionalised Chinese men and women aged 55-76 years from Beijing and Shanghai were included. Urinary nickel concentrations were assessed by inductively coupled plasma mass spectroscopy. Plasma uric acid, urea nitrogen, C reactive protein and urinary albumin, ß2-microglobulin and creatinine were measured. Albuminuria was defined as urinary albumin ≥30 mg/g creatinine, and ß2-microglobulinuria was defined as urinary ß2-microglobulin ≥200 µg/g creatinine. RESULTS: Median concentration of urinary nickel was 3.95 µg/g creatinine (IQR: 2.57-6.71 µg/g creatinine), and prevalence of albuminuria, ß2-microglobulinuria and both albuminuria and ß2-microglobulinuria was 22.1%, 24.5% and 9.7%, respectively. Comparing the highest with the lowest quartile of urinary nickel, the ORs (95% CIs) were 1.99 (1.46 to 2.78) for albuminuria, 1.44 (1.07 to 1.95) for ß2-microglobulinuria, and 2.95 (1.74 to 4.97) for both albuminuria and ß2-microglobulinuria, after adjustment for demographic characteristics, lifestyle behaviours, body mass index, hypertension and diabetes. The association remained significant when further controlling for inflammatory markers or other heavy metals (all p trend <0.05). CONCLUSIONS: This study suggested that urinary nickel levels were positively associated with albuminuria and ß2-microglobulinuria in Chinese men and women, who had relatively low background nickel exposure. More prospective studies are needed to confirm our findings.

Elevated plasma tumor necrosis factor-α receptor 2 and resistin are associated with increased incidence of kidney function decline in Chinese adults.

Adipokines and inflammatory markers have been linked to kidney disease in animal models; however, evidence from prospective human studies is sparse. Recruited from Beijing and Shanghai in 2005, a total number of 2220 non-institutionalized Chinese individuals aged 50-70 years with baseline estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m(2) were prospectively followed for 6 years. Plasma levels of resistin, retinol-binding protein 4 (RBP4), interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-α receptor 2 (TNF-R2) were determined at baseline. Kidney function decrease was assessed by measurements of eGFR over 6 years. Incident-reduced eGFR was defined as the onset of eGFR <60 mL/min/1.73 m(2), according to the Modification of Diet in Renal Disease Study Equation for Chinese. During the 6 years of follow-up, 333 (15.0 %) participants had incident-reduced eGFR. Each 1 standard deviation elevated concentration of resistin [relative risk (RR) 1.10; 95 % CI 1.00-1.24] and TNFR-2 (RR 1.30; 95 % CI 1.13-1.49) at baseline were significantly associated with a higher risk of incident-reduced eGFR. Comparing the highest with the lowest quartiles, the RR of incident-reduced eGFR was 1.43 (95 % CI 1.01-2.03) for resistin and 2.03 (95 % CI 1.41-2.93) for TNF-R2 (both P trend < 0.05) after adjustment for baseline demographic characteristics, lifestyle behaviors, BMI, plasma lipid profile, hypertension, and diabetes. These associations remained significant when further controlling for levels of RBP4, IL-6, and CRP, none of which was significantly associated with the risk of incident-reduced eGFR. In this prospective cohort study, elevated levels of resistin and TNF-R2, but not other adipokines and inflammatory markers, were independently associated with a greater risk of kidney function decline in middle-aged and elderly Chinese.

[Association of single nucleotide polymorphisms of IL-6 gene with longevity in Uyghurs in Xinjiang].

OBJECTIVE: To investigate whether the variations of genes encoding pro-inflammatory cytokines is associated with longevity in Uyghurs in Xinjiang. METHODS: A total of 240 individuals aged ≥90 years from Xinjiang Uyghur Autonomous Region were enrolled between 1999 and 2012 as the longevity group, 92 unrelated individuals from the same area who died naturally at the age of 59-73 in the same period were selected as the control group. Seven single nucleotide polymorphisms (SNPs) of 4 genes (tumor necrosis factor (TNF)-α(rs1800629), IL-6(rs1800796, rs10499563), C-reactive protein (CRP) (rs2808630, rs1205) and IL-1ß(rs1143623, rs16944)) were genotyped. Logistic regression was applied to assess the association between each individual SNP and longevity in case-control analyses. RESULTS: The distribution of C allele of rs1800796 in the longevity group (0.298) was lower than that in the control group (0.435) with statistical significance (P=0.001). The distributions of the other 6 genetic variations between the longevity group and the control group showed no statistically significant differences (all P>0.05). CT genotype of rs1800796 was positively associated with longevity (Padd=0.002, OR=1.983, 95%CI: 1.296-3.023), while no significant association was noted between other genotypes and longevity. CONCLUSIONS: SNP of rs1800796 of IL-6 gene may be significantly associated with longevity in Uyghurs in Xinjiang. CT genotype of rs1800796 is significantly associated with longevity. C allele of rs1800796 may be a negative factor for longevity.

Nickel exposure is associated with the prevalence of type 2 diabetes in Chinese adults.

BACKGROUND: Nickel exposure can induce hyperglycaemia in rodents, but little is known about its association with abnormal glucose metabolism in humans. We aimed to investigate the association of nickel exposure with the prevalence of type 2 diabetes in Chinese adults. METHODS: A total of 2115 non-institutionalized men and women aged 55 to 76 years from Beijing and Shanghai were included, and urinary nickel concentration was assessed by inductively coupled plasma mass spectroscopy. The prevalence of type 2 diabetes was compared across urinary nickel quartiles. Fasting plasma glucose, insulin, lipids, C-reactive protein and glycated haemoglobin A1c, as well as urinary albumin and creatinine were measured. RESULTS: The median concentration of urinary nickel was 3.63 mg/l (interquartile range: 2.29­5.89 mg/l), and the prevalence of diabetes was 35.3% (747 cases/2115 persons). Elevated levels of urinary nickel were associated with higher fasting glucose, glycated haemoglobin A1c, insulin and homeostatic model assessment of insulin resistance (all P<0.01). The odds ratios (95% confidence interval) for diabetes across the increasing urinary nickel quartiles were 1.27 (0.97­1.67), 1.78 (1.36­2.32) and 1.68 (1.29­2.20), respectively (referencing to 1.00), after multivariate adjustment including lifestyle factors, body mass index and family history of diabetes (P for trend <0.001). The association remained unchanged after further controlling for urinary creatinine and C-reactive protein (P for trend <0.001). CONCLUSIONS: Increased urinary nickel concentration is associated with elevated prevalence of type 2 diabetes in humans.

A meta-analysis of genome-wide association studies for adiponectin levels in East Asians identifies a novel locus near WDR11-FGFR2.

Blood levels of adiponectin, an adipocyte-secreted protein correlated with metabolic and cardiovascular risks, are highly heritable. Genome-wide association (GWA) studies for adiponectin levels have identified 14 loci harboring variants associated with blood levels of adiponectin. To identify novel adiponectin-associated loci, particularly those of importance in East Asians, we conducted a meta-analysis of GWA studies for adiponectin in 7827 individuals, followed by two stages of replications in 4298 and 5954 additional individuals. We identified a novel adiponectin-associated locus on chromosome 10 near WDR11-FGFR2 (P = 3.0 × 10(-14)) and provided suggestive evidence for a locus on chromosome 12 near OR8S1-LALBA (P = 1.2 × 10(-7)). Of the adiponectin-associated loci previously described, we confirmed the association at CDH13 (P = 6.8 × 10(-165)), ADIPOQ (P = 1.8 × 10(-22)), PEPD (P = 3.6 × 10(-12)), CMIP (P = 2.1 × 10(-10)), ZNF664 (P = 2.3 × 10(-7)) and GPR109A (P = 7.4 × 10(-6)). Conditional analysis at ADIPOQ revealed a second signal with suggestive evidence of association only after conditioning on the lead SNP (Pinitial = 0.020; Pconditional = 7.0 × 10(-7)). We further confirmed the independence of two pairs of closely located loci (<2 Mb) on chromosome 16 at CMIP and CDH13, and on chromosome 12 at GPR109A and ZNF664. In addition, the newly identified signal near WDR11-FGFR2 exhibited evidence of association with triglycerides (P = 3.3 × 10(-4)), high density lipoprotein cholesterol (HDL-C, P = 4.9 × 10(-4)) and body mass index (BMI)-adjusted waist-hip ratio (P = 9.8 × 10(-3)). These findings improve our knowledge of the genetic basis of adiponectin variation, demonstrate the shared allelic architecture for adiponectin with lipids and central obesity and motivate further studies of underlying mechanisms.

Joint analysis of multiple biomarkers for identifying type 2 diabetes in middle-aged and older Chinese: a cross-sectional study.

OBJECTIVE: Identifying individuals with high risk of type 2 diabetes is important. To evaluate discriminatory ability of multiple biomarkers for type 2 diabetes in a Chinese population. METHODS: Plasma adiponectin, plasminogen activator inhibitor-1, retinol-binding protein 4, resistin, C-reactive protein, interleukin 6 (IL-6), tumour necrosis factor α receptor 2 and ferritin were measured in a population-based sample of 3189 Chinese (1419 men and 1770 women) aged 50-70 years. A weighted biomarkers risk score (BRS) was developed based on the strength of associations of these biomarkers with type 2 diabetes. The discriminatory ability was tested by the area under receiver operating characteristics curve (AUC). RESULTS: Adiponectin, plasminogen activator inhibitor-1, IL-6 and ferritin were independently associated with the prevalence of type 2 diabetes, and they were used to calculate the biomarkers risk score (BRS). After adjustment for the confounding factors, the ORs for type 2 diabetes and impaired fasting glucose with each point increment of BRS were 1.28 (95% CI 1.22 to 1.34) and 1.16 (1.12 to 1.20), respectively. Compared with those in the lowest quintile of the BRS, the participants in the highest quintile have an OR (95% CI) of 6.67 (4.21 to 10.55) for type 2 diabetes. The area under the curve for the BRS and conventional risk factors alone was 0.73 and 0.76, respectively, and substantially increased to 0.81 after combining both BRS and conventional risk factors (p<0.001). CONCLUSIONS: These data suggest that combining multiple biomarkers and conventional risk factors might substantially enhance the ability to identify individuals with type 2 diabetes. More prospective data are warranted to confirm this observation.

Quantitative detection of single amino acid polymorphisms by targeted proteomics.

Single-nucleotide polymorphisms (SNPs) are recognized as one kind of major genetic variants in population scale. However, polymorphisms at the proteome level in population scale remain elusive. In the present study, we named amino acid variances derived from SNPs within coding regions as single amino acid polymorphisms (SAPs) at the proteome level, and developed a pipeline of non-targeted and targeted proteomics to identify and quantify SAP peptides in human plasma. The absolute concentrations of three selected SAP-peptide pairs among 290 Asian individuals were measured by selected reaction monitoring (SRM) approach, and their associations with both obesity and diabetes were further analyzed. This work revealed that heterozygotes and homozygotes with various SAPs in a population could have different associations with particular traits. In addition, the SRM approach allows us for the first time to separately measure the absolute concentration of each SAP peptide in the heterozygotes, which also shows different associations with particular traits.

Associations of amylin with inflammatory markers and metabolic syndrome in apparently healthy Chinese.

BACKGROUND: Cellular and animal studies implicate multiple roles of amylin in regulating insulin action, glucose and lipid metabolisms. However, the role of amylin in obesity related metabolic disorders has not been thoroughly investigated in humans. Therefore, we aimed to evaluate the distribution of circulating amylin and its association with metabolic syndrome (MetS) and explore if this association is influenced by obesity, inflammatory markers or insulin resistance in apparently healthy Chinese. METHODS: A population-based sample of 1,011 Chinese men and women aged 35-54 years was employed to measure plasma amylin, inflammatory markers (C-reactive protein [CRP] and interleukin-6 [IL-6]), insulin, glucose and lipid profiles. MetS was defined according to the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian-Americans. RESULTS: Plasma amylin concentrations were higher in overweight/obese participants than normal-weight counterparts (P<0.001) without sex difference. Circulating amylin was positively associated with CRP, IL-6, BMI, waist circumference, blood pressure, fasting glucose, insulin, amylin/insulin ratio, HOMA-IR, LDL cholesterol and triglycerides, while negatively associated with HDL cholesterol (all P<0.001). After multiple adjustments, the risk of MetS was significantly higher (odds ratio 3.71; 95% confidence interval: 2.53 to 5.46) comparing the highest with the lowest amylin quartile. The association remained significant even further controlling for BMI, inflammatory markers, insulin or HOMA-IR. CONCLUSIONS: Our study suggests that amylin is strongly associated with inflammatory markers and MetS. The amylin-MetS association is independent of established risk factors of MetS, including obesity, inflammatory markers and insulin resistance. The causal role of hyperamylinemia in the development of MetS needs to be confirmed prospectively.

Associations of alcohol consumption with diabetes mellitus and impaired fasting glycemia among middle-aged and elderly Chinese.

BACKGROUND: The U-shaped relationship between alcohol consumption and diabetes mellitus was observed among western populations. However, few studies have systematically evaluated the association in Chinese. We aimed to investigate the associations of alcohol consumption with diabetes mellitus and impaired fasting glycemia (IFG) among middle-aged and elderly Chinese. METHODS: We examined 1,458 men and 1,831 women aged 50 to 70 from Beijing and Shanghai China in a cross-sectional survey. Fasting glucose, adipokines and markers of inflammation were measured. Macronutrients and alcohol consumption were assessed with standardized questionnaires. RESULTS: Compared with abstainers, alcohol consumption was associated with a decreased risk of having diabetes mellitus in women (OR: 0.41, 95%CI: 0.22-0.78) after controlling for socio-demographic factors, physical activity, smoking, family income, family history of cardiovascular disease or diabetes, macronutrients intake, body mass index, and markers of inflammation and adipokines. In men, both low and high alcohol consumptions were associated with increased risks of having combined diabetes and IFG (ORs 1.36 [95%CI: 1.02-1.82] and 1.50 [95%CI: 1.04-2.15], respectively]. In the multivariable stratified analyses among men, moderate drinkers who had drinking days of ≥ 5 days/week had a deceased likelihood (OR: 0.61, 95%CI: 0.37-0.98) and liquor drinkers had an increased likelihood (OR: 1.47, 95%CI: 1.09-1.98) of having combined diabetes and IFG respectively, compared with the abstainers. CONCLUSIONS: An approximately J-shaped association was observed between alcohol consumption and combined diabetes and IFG among men compared with abstainers in Chinese. Whether moderate alcohol intake could help decrease diabetic risk among Chinese people warrants further investigation.

Lifestyle counseling and supplementation with flaxseed or walnuts influence the management of metabolic syndrome.

A healthy lifestyle may ameliorate metabolic syndrome (MetS); however, it remains unclear if incorporating nuts or seeds into lifestyle counseling (LC) has additional benefit. A 3-arm, randomized, controlled trial was conducted among 283 participants screened for MetS using the updated National Cholesterol Education Program Adult Treatment Panel III criteria for Asian Americans. Participants were assigned to a LC on the AHA guidelines, LC + flaxseed (30 g/d) (LCF), or LC + walnuts (30 g/d) (LCW) group. After the 12-wk intervention, the prevalence of MetS decreased significantly in all groups: -16.9% (LC), -20.2% (LCF), and -16.0% (LCW). The reversion rate of MetS, i.e. those no longer meeting the MetS criteria at 12 wk, was not significantly different among groups (LC group, 21.1%; LCF group, 26.6%; and LCW group, 25.5%). However, the reversion rate of central obesity was higher in the LCF (19.2%; P = 0.008) and LCW (16.0%; P = 0.04) groups than in the LC group (6.3%). Most of the metabolic variables (weight, waist circumference, serum glucose, total cholesterol, LDL cholesterol, apolipoprotein (Apo) B, ApoE, and blood pressure) were significantly reduced from baseline in all 3 groups. However, the severity of MetS, presented as the mean count of MetS components, was significantly reduced in the LCW group compared with the LC group among participants with confirmed MetS at baseline (P = 0.045). Our results suggest that a low-intensity lifestyle education program is effective in MetS management. Flaxseed and walnut supplementation may ameliorate central obesity. Further studies with larger sample sizes and of longer duration are needed to examine the role of these foods in the prevention and management of MetS.

A marker of endotoxemia is associated with obesity and related metabolic disorders in apparently healthy Chinese.

OBJECTIVE: Elevated lipopolysaccharide-binding protein (LBP), a marker of subclinical endotoxemia, may be involved in the pathogenesis of obesity and metabolic risk. We aimed to investigate the association between plasma LBP and metabolic disorders in apparently healthy Chinese. RESEARCH DESIGN AND METHODS: A population-based study including 559 overweight/obese (BMI >or=24.0 kg/m(2)) and 500 normal-weight (18.0

Associations of physical activity with inflammatory factors, adipocytokines, and metabolic syndrome in middle-aged and older chinese people.

BACKGROUND: Inflammatory factors, adipocytokines, and the metabolic syndrome are important determinants of cardiometabolic disease. It remains unclear how physical activity is related to these risk factors. Our objective was to investigate single and joint associations of physical activity with inflammatory factors, adipocytokines, and the metabolic syndrome among middle-aged and older Chinese people. METHODS AND RESULTS: A total of 3289 individuals (1458 men, 1831 women) 50 to 70 years of age participated in a population-based cross-sectional survey in Beijing and Shanghai, China. Levels of total physical activity were assessed with the International Physical Activity Questionnaire. High-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-alpha receptor 2, adiponectin, and retinol-binding protein 4 were measured. The metabolic syndrome was defined using the updated National Cholesterol Education Program/Adult Treatment Panel III criteria for Asian Americans. Plasma concentrations of high-sensitivity C-reactive protein were 1.58, 1.74, and 1.27 mg/L (P=0.0138) and of adiponectin were 16.12, 16.20, and 17.21 mg/L (P=0.0078) among individuals with low, medium, and high levels of total physical activity, respectively, with adjustment for potential confounders. In the multivariable-adjusted logistic regression analyses, participants with higher levels of total physical activity had a lower risk of having the metabolic syndrome (odds ratio, 0.68; 95% confidence interval, 0.54 to 0.85; P for trend=0.001) compared with those with lower levels. CONCLUSIONS: Being physically active is associated with a better profile of inflammatory factors and adipocytokines and a reduced risk of having the metabolic syndrome among Chinese people.

Obesity related metabolic abnormalities: distribution and geographic differences among middle-aged and older Chinese populations.

OBJECTIVE: To investigate geographic differences in obesity related metabolic abnormalities in middle-aged and older Chinese people with different levels of adiposity. METHOD: Data from 3289 individuals aged 50-70 years who participated in a cross-sectional survey in 2005 (1641 from northern [Beijing] and 1648 from southern [Shanghai] China) were analyzed. Overweight or obesity and abdominal obesity were classified as body mass index > or =24 kg/m2 and waist circumference > or =90 cm for men and > or =80 cm for women. Metabolic abnormalities (metabolic syndrome, dyslipidemia, hypertension and diabetes) were defined using the NCEP/ATPIII criteria. RESULTS: The overall prevalence of overweight and obesity was 53.4%, and the prevalence of abdominal obesity was 48.0%, respectively. The prevalence of the metabolic abnormalities was significantly higher among obese individuals than their normal weight counterparts. The association between obesity and the higher prevalence of the metabolic abnormalities was more pronounced among people who were overweight or obese in the north, especially for those living in rural areas. CONCLUSION: The prevalence of obesity and associated metabolic abnormalities varies substantially among Chinese people in different geographic region. Individuals who were overweight or obese living in rural areas in the north contribute importantly to the north-south differences in obesity-related metabolic abnormalities among Chinese populations.

Enterolactone inhibits insulin-like growth factor-1 receptor signaling in human prostatic carcinoma PC-3 cells.

Enterolactone, a major metabolite of plant-based lignans, has been shown to inhibit prostate cancer growth and development, but the mechanistic basis for its anticancer activity remains largely unknown. Activation of insulin-like growth factor-1 (IGF-1) receptor (IGF-1R) signaling is critical for prostate cancer cell growth and progression. This study examined whether the growth inhibitory effect of enterolactone was related to changes in the IGF-1/IGF-1R system in PC-3 prostate cancer cells. At nutritionally relevant concentrations (20-60 micromol/L), enterolactone inhibited IGF-1-induced activation of IGF-1R and its downstream AKT and mitogen-activated protein kinase/extracellular-signal regulated kinase signaling pathways. Inhibition of AKT by enterolactone resulted in decreased phosphorylation of its downstream targets, including p70S6K1 and glycogen synthase kinase-3 beta. Enterolactone also inhibited cyclin D1 expression. As a result, enterolactone inhibited proliferation and migration of PC-3 cells. Knockdown of IGF-1R by plasmids with siRNA (si) against IGF-1R mRNA resulted in inhibition of proliferation of PC-3 cells and cell numbers did not differ when the si-IGF-1R groups (cells transfected with plasmids containing siRNA against IGF-1R mRNA) were treated or untreated with enterolactone. These results suggest that enterolactone suppresses proliferation and migration of prostate cancer cells, at least partially, through inhibition of IGF-1/IGF-1R signaling. The finding of this study provides new insights into the molecular mechanisms that enterolactone exerts against prostate cancer.

Effects of a flaxseed-derived lignan supplement on C-reactive protein, IL-6 and retinol-binding protein 4 in type 2 diabetic patients.

Elevated C-reactive protein (CRP), IL-6 and retinol-binding protein 4 (RBP4) levels are associated with insulin resistance and diabetes mellitus. Phytoestrogens (including lignans and isoflavones) may enhance the management of diabetes and are hypothesized to act through inflammation pathways. The present study explored the effects of flaxseed-derived lignan on inflammatory factors and RBP4 concentrations in type 2 diabetics, who have higher levels of these biomarkers. Seventy community-dwelling diabetic patients (twenty-six men and forty-four post-menopausal women) with mild hypercholesterolaemia completed a randomized, double-blind, placebo-controlled, cross-over trial of supplementation with flaxseed-derived lignan capsules (360 mg/d) or placebo for 12 weeks, separated by an 8-week wash-out period. The participants maintained their habitual diets and levels of physical activity. Baseline to follow-up concentrations of CRP increased significantly within the placebo group (1.42 (sem 0.19) v. 1.96 (sem 0.22) mg/l, P < 0.001), but were comparatively unchanged in the lignan-supplemented group (1.67 (sem 0.19) v. 1.90 (sem 0.26) mg/l, P = 0.94); a significant difference was observed between treatments ( - 0.45 (95 % CI - 0.76, - 0.08) mg/l, P = 0.021). This effect was confined to women (P = 0.016), but not observed in men (P = 0.49). No between-treatment differences were found with regard to IL-6 or RBP4; though IL-6 concentrations increased significantly from baseline to follow-up in both groups (P = 0.004 and P < 0.001 following lignan and placebo treatments, respectively). The study suggests that lignan might modulate CRP levels in type 2 diabetics. These results need to be confirmed by further large clinical trials of longer duration.

Associations of inflammatory factors with glycaemic status among middle-aged and older Chinese people.

OBJECTIVE: Low-grade chronic inflammation is associated with risk for type 2 diabetes. We investigated the associations between inflammatory factors and glycaemic status in a middle-aged and older Chinese population. DESIGN: A population-based cross-sectional study of 3289 residents aged 50-70 years from Beijing and Shanghai. MEASUREMENTS: C-reactive protein (CRP), interleukin-6 (IL-6) and soluble tumour necrosis factor alpha-receptor two (sTNFR2) were assayed. RESULTS: Comparing the highest with the lowest quartile of CRP, the odds ratio (OR) of diabetes was significantly higher in women [3.66 (95% CI 2.23-6.03)] than in men [1.51 (0.95-2.41)] (P for interaction = 0.004), while the increased OR for impaired fasting glucose (IFG) was only observed in women [OR 2.03 (1.44-2.84)] (P for interaction = 0.022), after adjustment for age, geographic location, education, lifestyle factors, family history of diabetes, and use of antibiotics, aspirin and lipid-lowering drugs. The multiple-adjusted OR of IL-6 for diabetes was also higher in women [2.95 (1.78-4.90)] than in men [2.23 (1.39-3.59)] (P for interaction = 0.045). sTNFR2 was not associated with diabetes but inversely associated with IFG in men [OR 0.59 (0.41-0.85)] and women [OR 0.78 (0.56-1.09)] (P for interaction = 0.13). In addition, CRP was significantly associated with increased HbA(1c) in both genders within euglycaemia after multiple adjustments. CONCLUSIONS: Inflammatory markers are closely associated with diabetes and IFG in Chinese people. These associations appear to be stronger in women than in men. Furthermore, plasma CRP is positively associated with HbA(1c) even in euglycaemic individuals.