Doctor of Philosophy, University of California Los Angeles (2013)
Master of Science, National Taiwan University (2005)
Bachelor of Science, National Taiwan University (2003)
Crosstalk between lipids and osteoporosis/fractures
We will investigate whether midlife women with CVD-prone lipid levels (such as high TC, high TG, low HDL-C, or high LDL-C) will have greater subsequent fracture risk, compared to women who do not have CVD-prone lipid levels. Are lipid levels closer to the time of the FMP stronger risk factors for subsequent fracture? Do women with greater chronic inflammation have a higher fracutre risk related to CVD-prone lipid levels, than women with less chronic inflammation?
Stanford, CA, USA
We will investigate whether midlife women with CVD-prone lipid levels (such as high TC, high TG, low HDL-C, or high LDL-C) will have greater subsequent bone loss, compared to women who do not have CVD-prone lipid levels.
Are lipid levels closer to the time of the final menstrual period stronger risk factors for low bone mineral density (BMD) or BMD loss?
Do women with greater chronic inflammation have a higher risk of BMD loss related to CVD-prone lipid levels, than women with less chronic inflammation?
Stanford, CA, USA
One-carbon metabolism (folate metabolism) is considered important in carcinogenesis because of its involvement in DNA synthesis and biological methylation reactions. We investigated the associations of single nucleotide polymorphisms (SNPs) in folate metabolic pathway and the risk of three GI cancers in a population-based case-control study in Taixing City, China, with 218 esophageal cancer cases, 206 stomach cancer cases, 204 liver cancer cases, and 415 healthy population controls. Study participants were interviewed with a standardized questionnaire, and blood samples were collected after the interviews. We genotyped SNPs of the MTHFR, MTR, MTRR, DNMT1, and ALDH2 genes, using PCR-RFLP, SNPlex, or TaqMan assays. To account for multiple comparisons and reduce the chances of false reports, we employed semi-Bayes (SB) shrinkage analysis. After shrinkage and adjusting for potential confounding factors, we found positive associations between MTHFR rs1801133 and stomach cancer (any T versus C/C, SB odds-ratio [SBOR]: 1.79, 95% posterior limits: 1.18, 2.71) and liver cancer (SBOR: 1.51, 95% posterior limits: 0.98, 2.32). There was an inverse association between DNMT1 rs2228612 and esophageal cancer (any G versus A/A, SBOR: 0.60, 95% posterior limits: 0.39, 0.94). In addition, we detected potential heterogeneity across alcohol drinking status for ORs relating MTRR rs1801394 to esophageal (posterior homogeneity P = 0.005) and stomach cancer (posterior homogeneity P = 0.004), and ORs relating MTR rs1805087 to liver cancer (posterior homogeneity P = 0.021). Among non-alcohol drinkers, the variant allele (allele G) of these two SNPs was inversely associated with the risk of these cancers; while a positive association was observed among ever-alcohol drinkers. Our results suggest that genetic polymorphisms related to one-carbon metabolism may be associated with cancers of the esophagus, stomach, and liver. Heterogeneity across alcohol consumption status of the associations between MTR/MTRR polymorphisms and these cancers indicates potential interactions between alcohol drinking and one-carbon metabolic pathway.
View details for DOI 10.1371/journal.pone.0109235
View details for Web of Science ID 000343674800009
View details for PubMedID 25337902
Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors involved in several biological processes such as inflammation, cancer growth, progression and apoptosis that are important in lung and upper aero-digestive tract (UADT) cancer outcomes. Nonetheless, there are no published studies of the relationship between PPARs gene polymorphisms and survival of patients with lung cancer or UADT cancers.1212 cancer patients (611 lung, 303 oral, 100 pharyngeal, 90 laryngeal, and 108 esophageal) were followed for a median duration of 11 years. We genotyped three potentially functional single nucleotide polymorphisms (SNPs) using Taqman - rs3734254 of the gene PPARD and rs10865710 and rs1801282 of the gene PPARG - and investigated their associations with lung and UADT cancer survival using Cox regression. A semi-Bayesian shrinkage approach was used to reduce the potential for false positive findings when examining multiple associations.The variant homozygote CC (vs. TT) of PPARD rs3734254 was inversely associated with mortality of both lung cancer (adjusted hazard ratio [aHR]=0.63, 95% confidence interval [CI]=0.42, 0.96) and UADT cancers (aHR=0.51, 95% CI=0.27, 0.99). Use of the semi-Bayesian shrinkage approach yielded a posterior aHR for lung cancer of 0.66 (95% posterior limits=0.44, 0.98) and a posterior aHR for UADT cancers of 0.58 (95% posterior limits=0.33, 1.03).Our findings suggest that lung-cancer patients with the CC variant of PPARD rs3734254 may have a survival advantage over lung-cancer patients with other gene variants.
View details for DOI 10.1016/j.lungcan.2014.06.014
View details for Web of Science ID 000341902500018
View details for PubMedID 25043640
Although single nucleotide polymorphisms (SNPs) of NBS1 have been associated with susceptibility to lung and upper aerodigestive tract (UADT) cancers, their relations to cancer survival and measures of effect are largely unknown.Using follow-up data from 611 lung cancer cases and 601 UADT cancer cases from a population-based case-control study in Los Angeles, we prospectively evaluated associations of tobacco smoking and 5 NBS1 SNPs with all-cause mortality. Mortality data were obtained from the Social Security Death Index. We used Cox regression to estimate adjusted hazard ratios (HR) for main effects and ratios of hazard ratios (RHR) derived from product terms to assess hazard ratio variations by each SNP. Bayesian methods were used to account for multiple comparisons.We observed 406 (66 %) deaths in lung cancer cases and 247 (41 %) deaths in UADT cancer cases with median survival of 1.43 and 1.72 years, respectively. Ever tobacco smoking was positively associated with mortality for both cancers. We observed an upward dose-response association between smoking pack-years and mortality in UADT squamous cell carcinoma. The adjusted HR relating smoking to mortality in non-small cell lung cancer (NSCLC) was greater for cases with the GG genotype of NBS1 rs1061302 than for cases with AA/AG genotypes (semi-Bayes adjusted RHR = 1.97; 95 % limits = 1.14, 3.41).A history of tobacco smoking at cancer diagnosis was associated with mortality among patients with lung cancer or UADT squamous cell carcinoma. The HR relating smoking to mortality appeared to vary with the NBS1 rs1061302 genotype among NSCLC cases.
View details for DOI 10.1007/s10552-013-0303-0
View details for Web of Science ID 000329351700002
View details for PubMedID 24166361
This study was conducted to compare the risk of recurrent hospitalization for major gastrointestinal (GI) complications (peptic ulcer, bleeding, and perforation) in patients at high GI risk who require ongoing antiplatelet therapy (aspirin [acetylsalicylic acid] or clopidogrel) with or without proton pump inhibitors (PPIs).This population-based, retrospective cohort study employed data from the Taiwanese National Health Insurance database (January 2001 through December 2006) for patients who had a history of hospitalization for GI complications before the initiation of antiplatelet therapy with aspirin or clopidogrel. Recurrent hospitalizations for major GI complications were analyzed using a Cox proportional hazards model, with adjustment for age, sex, ulcer-related medical history, ulcer-related risk factors, and use of ulcer-related medications during follow-up. The propensity score method was applied to adjust for selection bias.The analysis included data from 14,627 patients (12,001 receiving aspirin, 2626 receiving clopidogrel). The incidence of recurrent hospitalization for major GI complications was 0.125 per person-year in aspirin users, 0.103 per person-year in users of aspirin plus a PPI, 0.128 per person-year in clopidogrel users, and 0.152 per person-year in users of clopidogrel plus a PPI. Among aspirin users, those taking PPIs had a significantly lower adjusted risk of hospitalization for major GI complications than did non-PPI users (hazard ratio [HR] = 0.76; 95% CI, 0.64-0.91). Use of a PPI was not associated with a significant risk reduction among clopidogrel users (HR = 1.08; 95% CI, 0.89-1.33). An adjusted survival curve for the risk of recurrent hospitalization for major GI complications indicated that the risk increased numerically faster in clopidogrel users compared with those using aspirin plus a PPI, although the mean drug cost per person-year was 5.08 times higher in clopidogrel users than in users of aspirin plus a PPI.In this analysis in patients at high GI risk who were receiving antiplatelet therapy for the secondary prevention of cardiovascular events, aspirin plus a PPI was associated with a reduced risk of recurrent hospitalization for major GI complications. This was not the case for clopidogrel plus a PPI.
View details for DOI 10.1016/j.clinthera.2009.09.005
View details for Web of Science ID 000271043100014
View details for PubMedID 19843493