Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 416
Filtrar
1.
Int J Cancer ; 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35001362

RESUMO

Colorectal cancer (CRC) is a major contributor to cancer death globally. Several studies showed some protections by certain individual dietary antioxidants against CRC development. Epidemiologic data on the composite dietary antioxidant index (CDAI) in relation to CRC risk are sparse. Using the Singapore Chinese Health Study, an ongoing prospective cohort consisting of 61 321 cancer-free participants aged 45 to 74 years at baseline, a food-based CDAI was calculated according to a previously established and validated method that included six food-sourced antioxidants including vitamins A, C and E, manganese, selenium and zinc. Cox proportional hazard regression method was used to estimate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for CRC associated with various levels of CDAI with adjustment for multiple potential confounders. After an average of 17.5 years of follow-up, 2140 participants developed CRC. HRs (95% CIs) of CRC for quartiles 2, 3 and 4 of CDAI were 0.94 (0.83-1.07), 0.86 (0.75-1.00) and 0.80 (0.66-0.98), respectively, compared to the lowest quartile (Ptrend  = .02). This inverse association between CDAI and CRC risk was more apparent in women or those without a history of diabetes, without family history of CRC, never smokers or overweight/obese individuals. However, none of the heterogeneity tests for the CDAI-CRC risk association reached statistical significance. Our findings suggest that food-based antioxidants may be beneficial for reducing the risk of CRC in the general population.

2.
Int J Epidemiol ; 50(6): 2070-2081, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34999862

RESUMO

BACKGROUND: Little is known about the time course of mortality reduction following smoking cessation in Asians who have smoking behaviours distinct from their Western counterparts. We evaluated the level of reduction in all-cause, cardiovascular disease (CVD) and lung cancer mortality by years since quitting smoking, in Asia. METHODS: Using Cox regression, we analysed individual participant data (n = 709 151) from 16 prospective cohorts conducted in China, Japan, Korea/Singapore, and India/Bangladesh, separately by cohorts. Cohort-specific hazard ratios (HRs) were combined using a random-effects meta-analysis. RESULTS: During a mean follow-up of 12.0 years, 108 287 deaths were ascertained-35 658 from CVD and 7546 from lung cancer. Among Asian men, a dose-response relationship of risk reduction in deaths from all causes, CVD and lung cancer was observed with an increase in years after smoking cessation. Compared with never smokers, however, all-cause and CVD mortality among former smokers remained elevated 10-14 years after quitting [multivariable-adjusted HR (95% confidence interval (CI) = 1.25 (1.13-1.37) and 1.20 (1.02-1.41), respectively]. Lung cancer mortality stayed almost 2-fold higher than among never smokers 15-19 years after smoking cessation [1.97 (1.41-2.73)], particularly among former heavy smokers [2.62 (1.71-4.00)]. Women who quitted for ≥5 years retained a significantly elevated mortality from all causes, CVD and lung cancer. Overall patterns of the cessation-mortality associations were similar across countries. CONCLUSIONS: Our findings suggest that adverse effects of tobacco smoking persist for an extended time period, even for more than two decades, which is beyond the time windows defined in current clinical guidelines for risk assessment of lung cancer and CVD.

3.
Thyroid ; 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-34915752

RESUMO

Background: Although previous meta-analyses have suggested a dose-response relationship between body mass index (BMI) and thyroid cancer risk, limited evidence has been presented about Asian populations. To assess this association among Asian populations, where underweight is more prevalent than in other regions, a pooled analysis from the Asia Cohort Consortium was conducted. Methods: Baseline height and weight were measured in five cohorts and self-reported in eight cohorts. Thyroid cancer incidence was ascertained by linkage to local cancer registries. Cohorts were treated as a stratum in the Cox proportional hazard model to estimate the pooled hazard ratios (HRs) and corresponding confidence intervals (CIs) from the estimates for each cohort. All analyses were stratified by sex. Results: A total of 538,857 men and women from 13 cohorts from mainland China, Korea, Japan, and Singapore were included in the analysis. During a mean of 15.1 years of follow-up, 1132 thyroid cancer cases were ascertained. Using a BMI of 18.5-22.9 kg/m2 as a reference, an elevated risk of thyroid cancer was observed for groups with a BMI between 25 and 29.9 kg/m2 (HR: 1.31, [CI: 0.95-1.80]) and a BMI of 30 kg/m2 and greater (HR: 1.84, [CI: 0.89-3.81]) in men. Thyroid cancer risk was elevated in women with a BMI of 23-24.9 kg/m2 (HR: 1.26, [CI: 1.07-1.48]). The HRs for 5-U increment of BMI showed a linear association among men (HR: 1.25, [CI 1.10-1.55]) but not among women (HR: 1.07, [CI: 0.97-1.18]). Although the overall thyroid cancer risk was lower among underweight men and women, the papillary cancer risk may be elevated among underweight men (HR: 2.24, [CI: 0.75-6.66]). Conclusion: While higher BMI is associated with an elevated risk of thyroid cancer in both men and women, the association of underweight BMI may differ by sex and histological subtype.

4.
JGH Open ; 5(12): 1363-1372, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34950780

RESUMO

Background and Aim: Chronic hepatitis C virus (HCV) infection, long-term alcohol use, cigarette smoking, and obesity are the major risk factors for hepatocellular carcinoma (HCC) in the United States, but the disease risk varies substantially among individuals with these factors, suggesting host susceptibility to and gene-environment interactions in HCC. To address genetic susceptibility to HCC, we conducted a genome-wide association study (GWAS). Methods: Two case-control studies on HCC were conducted in the United States. DNA samples were genotyped using the Illumian microarray chip with over 710 000 single nucleotide polymorphisms (SNPs). We compared these SNPs between 705 HCC cases and 1455 population controls for their associations with HCC and verified our findings in additional studies. Results: In this GWAS, we found that two SNPs were associated with HCC at P < 5E-8 and six SNPs at P < 5E-6 after adjusting for age, sex, and the top three principal components (PCs). Five of the SNPs in chromosome 22q13.31, three in PNPLA3 (rs2281135, rs2896019, and rs4823173) and two in SAMM50 (rs3761472, rs3827385), were replicated in a small US case-control study and a cohort study in Singapore. The associations remained significant after adjusting for body mass index and HCV infection. Meta-analysis of multiple datasets indicated that these SNPs were significantly associated with HCC. Conclusions: SNPs in PNPLA3 and SAMM50 are known risk loci for nonalcoholic fatty liver disease (NAFLD) and are suspected to be associated with HCC. Our GWAS demonstrated the associations of these SNPs with HCC in a US population. Biological mechanisms underlying the relationship remain to be elucidated.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34642175

RESUMO

While the associations between individual lifestyle factors and risk of pancreatic cancer were studied extensively, their combined impact has not been examined. We evaluated the association of a composite score of healthy lifestyle factors, including body mass index, cigarette smoking, the Alternative Healthy Eating Index-2010 (AHEI-2010), sleep duration, and physical activity with pancreatic cancer risk in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63,257 Chinese aged 45 to 74 years at enrollment in 1993 to 1998 with up to 25 years of follow up. Cox proportional hazard regression method was used to estimate HR and its 95% confidence interval (CI) with adjustment for multiple potential confounders. We identified 316 incident pancreatic cancer cases among the cohort participants after a mean 17 years of follow up. Individuals with higher composite scores representing healthier lifestyle were at significantly lower risk of pancreatic cancer. The multivariate-adjusted HRs (95% CIs) of pancreatic cancer incidence for the composite scores 2, 3, 4, 5, 6 to 7 were 0.60 (0.50-0.91), 0.48 (0.32-0.71), 0.45 (0.31-0.67), 0.41 (0.27-0.62), and 0.38 (0.24-0.62), respectively, compared with the scores 0 to 1 (P trend < 0.0001). The inverse association was more apparent among participants without diabetes history and was robust in men and women as well as in alcohol drinkers and nondrinkers. In summary, the association for pancreatic cancer risk was stronger for the aggregated than individual healthy lifestyle factors. These findings suggest that a more comprehensive lifestyle modification strategy would be more effective for prevention of pancreatic cancer than the change of a single lifestyle factor. PREVENTION RELEVANCE: In this large prospective Asian study, we calculated a composite score of healthy lifestyle factors, including body mass index, cigarette smoking, the Alternative Healthy Eating Index-2010 (AHEI-2010), sleep duration, and physical activity and found this composite score was associated with a significant reduction in pancreatic cancer risk, by as much as 62%. This finding suggests that public health programs emphasizing comprehensive lifestyle modification strategy would be more effective for prevention of pancreatic cancer than the change of a single lifestyle factor.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34649958

RESUMO

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has become a major contributor to the rising incidence of hepatocellular carcinoma (HCC) in the United States and other developed countries. Iron, an essential metal primarily stored in hepatocytes, may play a role in the development of NAFLD-related HCC. Epidemiologic data on iron overload without hemochromatosis in relation to HCC are sparse. This study aimed to examine the associations between serum biomarkers of iron and the risk of HCC in patients with NAFLD. METHODS: We identified 18,569 patients with NAFLD using the University of Pittsburgh Medical Center electronic health records from 2004 through 2018. After an average 4.34 years of follow-up, 244 patients developed HCC. Cox proportional hazard regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of HCC incidence associated with elevated levels of iron biomarkers with adjustment for age, sex, race, body mass index, history of diabetes, and tobacco smoking. RESULTS: The HRs (95% CIs) of HCC for clinically defined elevation of serum iron and transferrin saturation were 2.91 (1.34-6.30) and 2.02 (1.22-3.32), respectively, compared with their respective normal range. No statistically significant association was observed for total iron-binding capacity or serum ferritin with HCC risk. CONCLUSIONS: Elevated levels of serum iron and transferrin saturation were significantly associated with increased risk of HCC among patients with NAFLD without hemochromatosis or other major underlying causes of chronic liver diseases. IMPACT: Clinical surveillance of serum iron level may be a potential strategy to identify patients with NAFLD who are at high risk for HCC.

8.
Int J Epidemiol ; 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34468722

RESUMO

BACKGROUND: Accumulating evidence suggests that consuming coffee may lower the risk of death, but evidence regarding tea consumption in Asians is limited. We examined the association between coffee and tea consumption and mortality in Asian populations. METHODS: We used data from 12 prospective cohort studies including 248 050 men and 280 454 women from the Asia Cohort Consortium conducted in China, Japan, Korea and Singapore. We estimated the study-specific association of coffee, green tea and black tea consumption with mortality using Cox proportional-hazards regression models and the pooled study-specific hazard ratios (HRs) using a random-effects model. RESULTS: In total, 94 744 deaths were identified during the follow-up, which ranged from an average of 6.5 to 22.7 years. Compared with coffee non-drinkers, men and women who drank at least five cups of coffee per day had a 24% [95% confidence interval (CI) 17%, 29%] and a 28% (95% CI 19%, 37%) lower risk of all-cause mortality, respectively. Similarly, we found inverse associations for coffee consumption with cardiovascular disease (CVD)-specific and cancer-specific mortality among both men and women. Green tea consumption was associated with lower risk of mortality from all causes, CVD and other causes but not from cancer. The association of drinking green tea with CVD-specific mortality was particularly strong, with HRs (95% CIs) of 0.79 (0.68, 0.91) for men and 0.78 (0.68, 0.90) for women who drank at least five cups per day of green tea compared with non-drinkers. The association between black tea consumption and mortality was weak, with no clear trends noted across the categories of consumption. CONCLUSIONS: In Asian populations, coffee consumption is associated with a lower risk of death overall and with lower risks of death from CVD and cancer. Green tea consumption is associated with lower risks of death from all causes and CVD.

9.
JAMA Netw Open ; 4(9): e2122837, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34477853

RESUMO

Importance: The association between long sleep duration and mortality appears stronger in East Asian populations than in North American or European populations. Objectives: To assess the sex-specific association between sleep duration and all-cause and major-cause mortality in a pooled longitudinal cohort and to stratify the association by age and body mass index. Design, Setting, and Participants: This cohort study of individual-level data from 9 cohorts in the Asia Cohort Consortium was performed from January 1, 1984, to December 31, 2002. The final population included participants from Japan, China, Singapore, and Korea. Mean (SD) follow-up time was 14.0 (5.0) years for men and 13.4 (5.3) years for women. Data analysis was performed from August 1, 2018, to May 31, 2021. Exposures: Self-reported sleep duration, with 7 hours as the reference category. Main Outcomes and Measures: Mortality, including deaths from all causes, cardiovascular disease, cancer, and other causes. Sex-specific hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards regression with shared frailty models adjusted for age and the key self-reported covariates of marital status, body mass index, smoking status, alcohol consumption, physical activity, history of diabetes and hypertension, and menopausal status (for women). Results: For 322 721 participants (mean [SD] age, 54.5 [9.2] years; 178 542 [55.3%] female), 19 419 deaths occurred among men (mean [SD] age of men, 53.6 [9.0] years) and 13 768 deaths among women (mean [SD] age of women, 55.3 [9.2] years). A sleep duration of 7 hours was the nadir for associations with all-cause, cardiovascular disease, and other-cause mortality in both men and women, whereas 8 hours was the mode sleep duration among men and the second most common sleep duration among women. The association between sleep duration and all-cause mortality was J-shaped for both men and women. The greatest association for all-cause mortality was with sleep durations of 10 hours or longer for both men (hazard ratio [HR], 1.34; 95% CI, 1.26-1.44) and women (HR, 1.48; 95% CI, 1.36-1.61). Sex was a significant modifier of the association between sleep duration and mortality from cardiovascular disease (χ25 = 13.47, P = .02), cancer (χ25 = 16.04, P = .007), and other causes (χ25 = 12.79, P = .03). Age was a significant modifier of the associations among men only (all-cause mortality: χ25 = 41.49, P < .001; cancer: χ25 = 27.94, P < .001; other-cause mortality: χ25 = 24.51, P < .001). Conclusions and Relevance: The findings of this cohort study suggest that sleep duration is a behavioral risk factor for mortality in both men and women. Age was a modifier of the association between sleep duration in men but not in women. Sleep duration recommendations in these populations may need to be considered in the context of sex and age.

10.
Mov Disord ; 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34402545

RESUMO

BACKGROUND: Ethnic-specific genetic risk assessment framework for Parkinson's disease (PD) is lacking for the Asian population. OBJECTIVE: We investigated the association of a polygenic risk score (PRS) with PD incidence in a population-based Asian prospective cohort. METHODS: Genetic, dietary, and lifestyle information were prospectively collected from 25,646 participants within the Singapore Chinese Health Study cohort. PRS was constructed with Asian-specific and top genome-wide association study variants. The association between PRS and PD incidence was evaluated with multivariable Cox proportional hazard models, Kaplan-Meier survival analysis, and concordance statistics. RESULTS: A total of 333 incident cases were identified after a follow-up period of more than 20 years. Participants with PRS in the top tertile (hazard ratio [HR], 1.81; 95% confidence interval [CI], 1.37-2.39) and middle tertile (HR, 1.35; 95% CI, 1.00-1.83) are at higher risk of developing PD after adjusting for dietary and lifestyle risk factors, with a shorter time to PD event in a Kaplan-Meier survival analysis (P < 0.001). CONCLUSION: We identified a PRS that was significantly associated with PD incidence in a prospective Chinese cohort after adjusting for dietary and lifestyle factors. © 2021 International Parkinson and Movement Disorder Society.

11.
Cancers (Basel) ; 13(16)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34439128

RESUMO

Small-cell-lung cancer (SCLC) is associated with overexpression of oncogenes including Myc family genes and YAP1 and inactivation of tumor suppressor genes. We performed in-depth proteomic profiling of plasmas collected from 15 individuals with newly diagnosed early stage SCLC and from 15 individuals before the diagnosis of SCLC and compared findings with plasma proteomic profiles of 30 matched controls to determine the occurrence of signatures that reflect disease pathogenesis. A total of 272 proteins were elevated (area under the receiver operating characteristic curve (AUC) ≥ 0.60) among newly diagnosed cases compared to matched controls of which 31 proteins were also elevated (AUC ≥ 0.60) in case plasmas collected within one year prior to diagnosis. Ingenuity Pathway analyses of SCLC-associated proteins revealed enrichment of signatures of oncogenic MYC and YAP1. Intersection of proteins elevated in case plasmas with proteomic profiles of conditioned medium from 17 SCLC cell lines yielded 52 overlapping proteins characterized by YAP1-associated signatures of cytoskeletal re-arrangement and epithelial-to-mesenchymal transition. Among samples collected more than one year prior to diagnosis there was a predominance of inflammatory markers. Our integrated analyses identified novel circulating protein features in early stage SCLC associated with oncogenic drivers.

12.
Cancer Epidemiol Biomarkers Prev ; 30(11): 2068-2078, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34446471

RESUMO

BACKGROUND: Limited research has been conducted on the effect of quality diet index (QDI), which represents a comprehensive assessment of healthy diet quality and quantity, on pancreatic cancer risk in Asian populations. METHODS: Using data from the Singapore Chinese Health Study, a prospective cohort of 63,257 middle-aged or older Chinese men and women, four QDI scores: the Alternative Health Eating Index-2010 (AHEI-2010), the alternate Mediterranean Diet (aMED), the Dietary Approaches to Stop Hypertension (DASH), and the Heathy Diet Indicator (HDI), at baseline were calculated. After 25 years of follow-up, 311 cohort participants developed pancreatic cancer. Cox proportional hazard regression method was used to estimate HR and 95% confidence interval (CI) for pancreatic cancer associated with higher QDI scores. RESULTS: Higher scores of AHEI-2010, aMED, and DASH were significantly associated with lower pancreatic cancer risk (all P trend < 0.05). Compared with the lowest quartile, HRs (95% CIs) of pancreatic cancer for the highest quartiles of AHEI-2010, aMED, and DASH scores were 0.65 (0.46-0.90), 0.57 (0.38-0.85), and 0.66 (0.46-0.95), respectively. These associations were more apparent among men. Overall, there was no statistically significant difference in the QDI-pancreatic cancer risk association between subgroups stratified by levels of body mass index, history of diabetes, and smoking status. CONCLUSIONS: Higher QDI scores were significantly associated with reduced risk of pancreatic cancer. IMPACT: The consistent results across multiple QDIs shows that adherence to a healthy diet may lower pancreatic cancer risk, suggesting that dietary modification may be a promising approach for primary prevention of pancreatic cancer.

13.
Sci Rep ; 11(1): 13805, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226613

RESUMO

Imbalances of blood biomarkers are associated with disease, and biomarkers may also vary non-pathologically across population groups. We described variation in concentrations of biomarkers of one-carbon metabolism, vitamin status, inflammation including tryptophan metabolism, and endothelial and renal function among cancer-free older adults. We analyzed 5167 cancer-free controls aged 40-80 years from 20 cohorts in the Lung Cancer Cohort Consortium (LC3). Centralized biochemical analyses of 40 biomarkers in plasma or serum were performed. We fit multivariable linear mixed effects models to quantify variation in standardized biomarker log-concentrations across four factors: age, sex, smoking status, and body mass index (BMI). Differences in most biomarkers across most factors were small, with 93% (186/200) of analyses showing an estimated difference lower than 0.25 standard-deviations, although most were statistically significant due to large sample size. The largest difference was for creatinine by sex, which was - 0.91 standard-deviations lower in women than men (95%CI - 0.98; - 0.84). The largest difference by age was for total cysteine (0.40 standard-deviation increase per 10-year increase, 95%CI 0.36; 0.43), and by BMI was for C-reactive protein (0.38 standard-deviation increase per 5-kg/m2 increase, 95%CI 0.34; 0.41). For 31 of 40 markers, the mean difference between current and never smokers was larger than between former and never smokers. A statistically significant (p < 0.05) association with time since smoking cessation was observed for 8 markers, including C-reactive protein, kynurenine, choline, and total homocysteine. We conclude that most blood biomarkers show small variations across demographic characteristics. Patterns by smoking status point to normalization of multiple physiological processes after smoking cessation.


Assuntos
Biomarcadores/sangue , Carbono/metabolismo , Inflamação/genética , Rim/metabolismo , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Proteína C-Reativa/genética , Feminino , Humanos , Inflamação/sangue , Inflamação/metabolismo , Inflamação/patologia , Cinurenina/sangue , Masculino , Pessoa de Meia-Idade , Fumar/genética , Abandono do Hábito de Fumar , Vitaminas/sangue
14.
RMD Open ; 7(2)2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34330847

RESUMO

OBJECTIVES: We aimed to evaluate the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe knee osteoarthritis (KOA). METHODS: We used data from the Singapore Chinese Health Study, a prospective cohort study that recruited 63 257 participants aged 45-74 years from 1993 to 1998. At baseline, we assessed diet using a validated 165-item semiquantitative food frequency questionnaire, together with body mass index (BMI) and lifestyle factors. Incident TKR cases were identified via record linkage with nationwide hospital discharge database through 2017. RESULTS: There were 2816 cases of incident TKR due to severe KOA. The total fibre intake at baseline was not associated with the risk of TKR after adjustment for confounders. Among the food sources of fibre, higher intake of legumes was associated with a lower risk of TKR in a dose-dependent manner; compared with those having the lowest quartile intake, HR (95% CI) was 0.86 (0.76, 0.96) for those having the highest quartile intake (p for trend=0.004). This association was consistent after including BMI in the model and homogeneous across BMI categories. The consumption of other fibre sources, namely grain products, nuts and seeds, soy food, fruits and vegetables, was not associated with the risk of TKR. CONCLUSION: Intake of legumes, but not total fibre, was associated with a reduced risk of TKR. Further research is needed to replicate our findings and to evaluate possible biological mechanisms that could explain the effect of dietary legumes on pathogenesis or progression of KOA.


Assuntos
Artroplastia do Joelho , Osteoartrite do Joelho , Artroplastia do Joelho/efeitos adversos , China , Fibras na Dieta , Humanos , Osteoartrite do Joelho/epidemiologia , Osteoartrite do Joelho/etiologia , Osteoartrite do Joelho/cirurgia , Estudos Prospectivos , Singapura/epidemiologia
15.
Cancers (Basel) ; 13(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071196

RESUMO

Hepatocellular carcinoma (HCC) is a commonly diagnosed malignancy with poor prognosis. Rising incidence of HCC may be due to rising prevalence of metabolic dysfunction-associated fatty liver disease, where altered bile acid metabolism may be implicated in HCC development. Thirty-five bile acids were quantified using ultra-performance liquid chromatography triple-quadrupole mass spectrometry assays in pre-diagnostic serum of 100 HCC cases and 100 matched controls from the Singapore Chinese Health Study. Conditional logistic regression was used to assess associations for bile acid levels with risk of HCC. Conjugated primary bile acids were significantly elevated whereas the ratios of secondary bile acids over primary bile acids were significantly lower in HCC cases than controls. The respective odds ratios and 95% confidence intervals of HCC were 6.09 (1.75-21.21) for highest vs. lowest tertile of cholic acid species and 30.11 (5.88-154.31) for chenodeoxycholic acid species. Doubling ratio of taurine-over glycine-conjugated chenodeoxycholic acid was associated significantly with 40% increased risk of HCC whereas doubling ratio of secondary over primary bile acid species was associated with 30-40% reduced risk of HCC. In conclusion, elevated primary bile acids and taurine over glycine-conjugated ratios were strongly associated with HCC risk whereas the ratios of secondary bile acids over primary bile acids were inversely associated with HCC risk.

16.
J Phys Chem B ; 125(23): 6068-6079, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34080429

RESUMO

Investigation of protein self-assembly processes is important for understanding the growth processes of functional proteins as well as disease-causing amyloids. Inside cells, intrinsic molecular fluctuations are so high that they cast doubt on the validity of the deterministic rate-equation approach. Furthermore, the protein environments inside cells are often crowded with other macromolecules, with volume fractions of the crowders as high as 40%. We have developed a stochastic kinetic framework using Gillespie's algorithm for general systems undergoing particle self-assembly, including particularly protein aggregation at the cellular level. The effects of macromolecular crowding are investigated using models built on scaled-particle and transition-state theories. The stochastic kinetic method can be formulated to provide information on the dominating aggregation mechanisms in a method called reaction frequency (or propensity) analysis. This method reveals that the change of scaling laws related to the lag time can be directly related to the change in the frequencies of reaction mechanisms. Further examination of the time evolution of the fibril mass and length quantities unveils that maximal fluctuations occur in the periods of rapid fibril growth and the fluctuations of both quantities can be sensitive functions of rate constants. The presence of crowders often amplifies the roles of primary and secondary nucleation and causes shifting in the relative importance of elongation, shrinking, fragmentation, and coagulation of linear aggregates. We also show a dual effect of changing volume on the halftime of aggregation for ApoC2 which is reduced in the presence of crowders. A comparison of the results of stochastic simulations with those of rate equations gives us information on the convergence relation between them and how the roles of reaction mechanisms change as the system volume is varied.


Assuntos
Amiloide , Agregados Proteicos , Algoritmos , Cinética , Substâncias Macromoleculares , Processos Estocásticos
17.
Int J Epidemiol ; 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34009320

RESUMO

BACKGROUND: Little is known about the time course of mortality reduction following smoking cessation in Asians who have smoking behaviours distinct from their Western counterparts. We evaluated the level of reduction in all-cause, cardiovascular disease (CVD) and lung cancer mortality by years since quitting smoking, in Asia. METHODS: Using Cox regression, we analysed individual participant data (n = 709 151) from 16 prospective cohorts conducted in China, Japan, Korea/Singapore, and India/Bangladesh, separately by cohorts. Cohort-specific hazard ratios (HRs) were combined using a random-effects meta-analysis. RESULTS: During a mean follow-up of 12.0 years, 108 287 deaths were ascertained-35 658 from CVD and 7546 from lung cancer. Among Asian men, a dose-response relationship of risk reduction in deaths from all causes, CVD and lung cancer was observed with an increase in years after smoking cessation. Compared with never smokers, however, all-cause and CVD mortality among former smokers remained elevated 10-14 years after quitting [multivariable-adjusted HR (95% confidence interval (CI) = 1.25 (1.13-1.37) and 1.20 (1.02-1.41), respectively]. Lung cancer mortality stayed almost 2-fold higher than among never smokers 15-19 years after smoking cessation [1.97 (1.41-2.73)], particularly among former heavy smokers [2.62 (1.71-4.00)]. Women who quitted for ≥5 years retained a significantly elevated mortality from all causes, CVD and lung cancer. Overall patterns of the cessation-mortality associations were similar across countries. CONCLUSIONS: Our findings suggest that adverse effects of tobacco smoking persist for an extended time period, even for more than two decades, which is beyond the time windows defined in current clinical guidelines for risk assessment of lung cancer and CVD.

18.
Commun Biol ; 4(1): 519, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941849

RESUMO

The role of low frequency variants associated with telomere length homeostasis in chronic diseases and mortalities is relatively understudied in the East-Asian population. Here we evaluated low frequency variants, including 1,915,154 Asian specific variants, for leukocyte telomere length (LTL) associations among 25,533 Singapore Chinese samples. Three East Asian specific variants in/near POT1, TERF1 and STN1 genes are associated with LTL (Meta-analysis P 2.49×10-14-6.94×10-10). Rs79314063, a missense variant (p.Asp410His) at POT1, shows effect 5.3 fold higher and independent of a previous common index SNP. TERF1 (rs79617270) and STN1 (rs139620151) are linked to LTL-associated common index SNPs at these loci. Rs79617270 is associated with cancer mortality [HR95%CI = 1.544 (1.173, 2.032), PAdj = 0.018] and 4.76% of the association between the rs79617270 and colon cancer is mediated through LTL. Overall, genetically determined LTL is particularly associated with lung adenocarcinoma [HR95%CI = 1.123 (1.051, 1.201), Padj = 0.007]. Ethnicity-specific low frequency variants may affect LTL homeostasis and associate with certain cancers.


Assuntos
Leucócitos/patologia , Neoplasias/epidemiologia , Polimorfismo de Nucleotídeo Único , Homeostase do Telômero , Proteínas de Ligação a Telômeros/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Estudos Transversais , Feminino , Humanos , Leucócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/patologia , Estudos Prospectivos , Singapura/epidemiologia , Adulto Jovem
19.
Nutr Metab Cardiovasc Dis ; 31(6): 1840-1844, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33992511

RESUMO

BACKGROUND AND AIMS: Glycine is involved in a wide range of metabolic pathways and increased circulating glycine is associated with reduced risk of cardio-metabolic diseases in Europeans but the genetic association between circulating glycine and cardiovascular risk is largely unknown in East Asians. METHODS AND RESULTS: We conducted a genome-wide association study (GWAS) in Singaporean Chinese participants and investigated if genetically determined serum glycine were associated with incident coronary artery disease (CAD) (711 cases and 1,246 controls), cardiovascular death (1,886 cases and 21,707 controls) and angiographic CAD severity (as determined by the Modified Gensini score, N = 1,138). CONCLUSION: Our study, a first in East Asians, suggest a protective role of glycine against CAD.


Assuntos
Carbamoil-Fosfato Sintase (Amônia)/genética , Doença da Artéria Coronariana/genética , Glicina/sangue , Polimorfismo de Nucleotídeo Único , /genética , Biomarcadores/sangue , Estudos de Casos e Controles , China/etnologia , Angiografia Coronária , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/etnologia , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Fatores de Risco de Doenças Cardíacas , Humanos , Incidência , Prognóstico , Estudos Prospectivos , Medição de Risco , Singapura/epidemiologia
20.
BMC Cancer ; 21(1): 589, 2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34022824

RESUMO

BACKGROUND: Blood type has been associated with the risk of gastric cancer, but few studies have examined the association with esophageal squamous cell carcinoma (ESCC). METHODS: We conducted a case-control study using genotyping data of Chinese individuals, including cases of 2022 ESCC, 1189 gastric cardia adenocarcinoma, 1161 gastric noncardia adenocarcinoma, and 2696 controls. Genetic blood type was imputed using three single nucleotide polymorphisms. We used logistic regression to examine the association between blood type and the risk of each cancer. RESULTS: Compared to blood type O, the risk of ESCC was significantly elevated for blood type B and AB, with the highest risk for type AB (OR, 95%CI: 1.34, 1.07-1.67). Analysis of genotype suggested that the association of ESCC was from carrying the B allele. Similarly, blood type was significantly associated with gastric noncardia adenocarcinoma (P < 0.001) with risk significantly elevated in type A (1.37, 1.14-1.65) and AB (1.44, 1.10-1.89) compared to type O. Blood type was not associated with gastric cardia adenocarcinoma (P = 0.13). CONCLUSIONS: This study provides novel insights into the association between blood type and the risk of ESCC and restricted previously observed association to only gastric noncardia cancer, providing important evidence to clarify the pattern of association and suggesting mechanisms of action.


Assuntos
Sistema ABO de Grupos Sanguíneos/genética , Adenocarcinoma/epidemiologia , Neoplasias Esofágicas/epidemiologia , Carcinoma de Células Escamosas do Esôfago/epidemiologia , Neoplasias Gástricas/epidemiologia , Adenocarcinoma/sangue , Estudos de Casos e Controles , China/epidemiologia , Neoplasias Esofágicas/sangue , Carcinoma de Células Escamosas do Esôfago/sangue , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Medição de Risco/métodos , Neoplasias Gástricas/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...