Association between consumption of fruits and vegetables in midlife and depressive symptoms in late life: the Singapore Chinese Health Study.

OBJECTIVES: Epidemiological evidence of how midlife intake of fruits and vegetables affects the likelihood of depressive symptoms in late life remains limited and controversial. We examined this association in an Asian cohort. DESIGN: Prospective population-based cohort study. SETTING: Chinese living in Singapore. PARTICIPANTS: A total of 13,738 adults from the Singapore Chinese Health Study. MEASUREMENTS: The consumption of 14 fruits and 25 vegetables were assessed using a validated 165-item food-frequency questionnaire at baseline (1993-1998), when participants were aged 45-74 years (mean age 52.4 years). Depressive symptoms were evaluated using the Geriatric Depression Scale during the third follow-up interviews (2014-2016), when participants were aged 61-96 years (mean age 72.5 years), and depression was defined by ≥5 out of 15 scores. Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: After a mean follow-up of 19.6 years, depressive symptoms were identified among 3,180 participants. Consumption of fruits was inversely associated with the odds of depressive symptoms in a dose-response manner: comparing extreme quartiles, the OR (95% CI) of depressive symptoms was 0.71 (0.63-0.81; P-trend <0.01). Intake of several types of fruits, especially orange, tangerine, banana, papaya and watermelon, was associated with reduced odds, and this inverse association was similar across subgroups of fruits categorized by glycemic index. Conversely, intake of vegetables was not associated with the odds of depressive symptoms. CONCLUSIONS: Our findings support population-based recommendation of having sufficient fruit intake early in life to reduce the likelihood of depressive symptoms in late life.

Reproductive factors and risk of physical frailty among Chinese women living in Singapore.

SETTING: Although age at menopause has been linked to higher risk of physical frailty in later life, little is known about other reproductive factors. OBJECTIVES: Our study aimed to investigate the associations between 1) age at menarche, 2) age at natural menopause, 3) duration of reproductive period, 4) number of children, 5) use of oral contraceptives (OCP), and 6) use of hormone replacement therapy (HRT) with the risk of physical frailty in late life. DESIGN: We used data from 5934 women of the Singapore Chinese Health Study who experienced natural menopause, and participated in the third follow-up interviews when physical frailty was assessed. Logistic regression was used to evaluate association of reproductive factors evaluated during baseline and prior follow-up interviews with physical frailty at follow-up 3. PARTICIPANTS: Community-dwelling Chinese women living in Singapore. Participants had a mean age of 52.6 years at baseline (1993-1998), and a mean age of 72.8 years during the third follow-up (2014-2017). MEASUREMENTS: Sociodemographic characteristics, level of education, smoking history, physical activity, and history of physician-diagnosed comorbidities were collected. Participants' weight and height were self-reported. We used a modified Cardiovascular Health Study phenotype to assess physical frailty. RESULTS: Age at menarche was inversely associated with the likelihood of physical frailty (Ptrend = 0.001); each one-year decrease in age at menarche was associated with a 9% increase (95% CI: 4%-14%) in odds of physical frailty. Age at menopause was also inversely associated with the likelihood of physical frailty (Ptrend = 0.009); every one-year decrease in age at menopause was associated with 2% (0%-4%) increased odds. In the assessment of frailty, younger ages at menarche and menopause were associated with greater likelihood of being in the slowest quintile for timed up-and-go and weakest quintile for handgrip strength. Conversely, duration of reproductive period, parity, and use of oral contraceptives or hormone replacement therapy were not significantly associated with the likelihood of physical frailty. CONCLUSIONS: In our population-based cohort of Chinese women, younger ages at menarche and menopause were associated with higher likelihood of physical frailty in later life.

Low-Carbohydrate Diet Score and Risk of Hepatocellular Carcinoma: Findings from a Prospective Cohort Study.

Limited data are reported on the association between low-carbohydrate diet (LCD) score, a comprehensive measure of dietary pattern according to sources of carbohydrate, fat, and protein, and risk of hepatocellular carcinoma (HCC). We evaluated this score with HCC risk in the Singapore Chinese Health Study, a prospective cohort of 63,275 middle-aged and elderly Chinese living in Singapore and recruited during 1993-1998 period. LCD scores were derived from the semi-quantitative food frequency questionnaire at baseline. A nested case-control study involved 197 HCC cases and 465 controls was also constructed among 28,346 participants who provided blood samples. Cox proportional hazard regression method was used to calculate HRs and 95% confidence intervals (CI) for HCC with different levels of LCD scores. Conditional logistic regression was performed for the case-control study analysis. After 17.6 years of follow-up with 819,573 person-years, 561 participants developed primary HCC. Although there was a null association between total LCD score and HCC risk (HRper-SD increment = 1.07; 95% CI, 0.98-1.16; Ptrend = 0.06), there was a positive association between animal-based LCD and the risk of HCC (HRper-SD increment = 1.11; 95% CI, 1.02-1.21; Ptrend = 0.01). Furthermore, this association was present in both HBsAg-negative and HBsAg-positive individuals in the case-control study. In stratified analysis for the entire cohort, this positive association was only present in those who consumed alcoholic beverages monthly or less frequent but not in weekly or daily drinker (Pinteraction = 0.79). In summary, a diet with lower carbohydrate, higher animal fat and protein was significantly associated with higher risk of HCC among Chinese Singaporeans. PREVENTION RELEVANCE: In a large cohort study of more than 63,000 Chinese Singaporeans, we found that a diet with lower carbohydrate and higher animal fat and protein was associated with increased risk of HCC, suggesting that dietary modification could be an effective strategy in primary prevention to reduce the HCC burden.

Low-Carbohydrate Diet Score and the Risk of Colorectal Cancer: Findings from the Singapore Chinese Health Study.

BACKGROUND: Colorectal cancer is common cancer with a high mortality rate. Low-carbohydrate diet (LCD) score holistically evaluates the LCD pattern from carbohydrate, protein, and fat intake. Epidemiologic data of LCD-colorectal cancer association are sparse. METHODS: We evaluated the associations between LCD (i.e., total, animal- and plant-based) and colorectal cancer risk in the Singapore Chinese Health Study, a population-based prospective cohort study including 61,321 Chinese in Singapore who were 45 to 74 years old at baseline. Cox proportional hazard regression model was used to determine the HRs and respective 95% confidence intervals (CI) for colorectal cancer associated with LCD after adjusting for potential confounders, including age, sex, BMI, physical activity, family history of colorectal cancer, etc. RESULTS: After an average of 19.5 years of follow-up, 2,520 participants developed colorectal cancer (1,608 colon cancer and 912 rectal cancer). Overall, the association between total or plant-based LCD scores with the risk of colorectal, colon, or rectal cancer was null (all Ptrend ≥ 0.28). The animal-based LCD was modestly associated with colon cancer risk (Ptrend = 0.02), but not with rectal cancer. Compared with the lowest quartile, HRs (95% CIs) of colon cancer for quartiles 2, 3, and 4 of animal-based LCD were 1.12 (0.98-1.29), 1.27 (1.10-1.46), and 1.14 (0.99-1.31), respectively. CONCLUSIONS: A low-level carbohydrate diet with a high level of animal protein and fat was associated with a moderate increase in the risk of colon cancer among Chinese Singaporeans. IMPACT: High consumption of animal protein/fat and low consumption of carbohydrates may increase colon cancer risk.

Soluble CD137 and risk of hepatocellular carcinoma: nested case-control studies in cohorts in Shanghai and Singapore.

BACKGROUND: The majority of hepatocellular carcinoma (HCC) cases occur in the presence of cirrhosis. Biomarkers of cirrhosis-associated immune dysfunction such as CD8+ T cell cytokines could aid HCC risk assessment. METHODS: CD8+ T cell cytokines were determined in pre-diagnostic serum in two studies including 315 HCC case-control pairs in the Shanghai Cohort Study (SCS) and 197 pairs in the Singapore Chinese Health Study (SCHS). Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for HCC with levels of five cytokines-soluble CD137 (sCD137), soluble Fas (sFas), perforin, macrophage inflammatory protein 1-beta (MIP-1ß), and tumour necrosis factor alpha (TNF-α). RESULTS: sCD137 levels were significantly higher in HCC cases than controls in both cohorts (Ps < 0.001). Compared with the lowest quartile, multivariable-adjusted ORs (95% CI) of HCC for the highest sCD137 quartile were 3.79 (1.73, 8.30) in the SCS and 3.49 (1.44, 8.48) in the SCHS. The sCD137-HCC association was independent of hepatitis B seropositivity and follow-up time. No other cytokine was consistently associated with HCC risk. CONCLUSION: sCD137 was associated with higher risk of HCC in two studies nested in general population cohorts. sCD137 may be a long-term risk marker of HCC development.

Dietary Nonstarch Polysaccharide Intake and Risk of Colorectal Cancer: Findings from the Singapore Chinese Health Study.

Dietary fiber or non-starch polysaccharides (NSP) may provide protection from CRC development. Epidemiologic studies on the association between dietary fiber and CRC is inconsistent are limited on NSP as a modifiable risk factor. Using the Singapore Chinese Health Study, a population-based prospective cohort of 61,321 cancer-free middle-aged or older Chinese Singaporeans, we examined the association between dietary fiber and NSP intakes and CRC risk. Fiber and NSP intakes at baseline were obtained using a validated semi-quantitative food frequency questionnaire coupled with the Singapore Food Composition Database. Cox proportional hazard regression model was used to estimate the hazard ratios (HRs) and respective 95% confidence intervals (CIs) for CRC associated with dietary fiber and NSP intakes after adjusting for potential confounders. After an average of 17.5 years of follow-up, 2,140 participants developed CRC. NSP was inversely associated with the risk of CRC in a dose-dependent manner whereas dietary fiber was not associated with risk of CRC overall or histologic subtypes. The multivariable-adjusted HRs (95% CIs) of CRC for quartiles 2, 3 and 4 of dietary NSP intake were 0.99 (0.88-1.11), 0.98 (0.87-1.11) and 0.84 (0.73-0.95), respectively, compared with the lowest quartile (P trend =0.006). This inverse association was more apparent for colon cancer (HRQ4 vs. Q1=0.79, 95% CI: 0.67-0.93, P trend =0.003) than rectal cancer (HR Q4 vs. Q1=0.92, 95% CI: 0.74-1.13, P trend =0.53). Our findings suggested that dietary NSP but not fiber is associated with a reduced risk of colon cancer in Chinese Singaporeans. Significance: Non-starch polysaccharides may be beneficial for colorectal cancer primary prevention.

CXCL9 Predicts the Risk of Osteoporotic Hip Fracture in a Prospective Cohort of Chinese Men-A Matched Case-Control Study.

Recent experimental work has identified CXCL9 as a promoter for the differentiation of osteoclast progenitors into osteoclasts, with resultant bone resorption. However, no human study has validated an association between this chemokine and osteoporosis or fracture risk. We conducted a matched case-control study nested in the prospective, population-based Singapore Chinese Health Study. Fifty-five men and 119 women with incident hip fractures, occurring median 6.2 years after blood collection, were matched individually to controls by age at recruitment, sex, and duration of blood storage. Serum chemokines, CXCL9 and CXCL10, were measured using immunoassays. Multivariable conditional logistic regression models that included age at blood collection, body mass index, smoking, and diabetes as covariates were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for association with hip fracture risk. Predictive utility of chemokine for hip fracture risk was examined by comparing area under receiver operating characteristic curves (AUC) between prognostic models with and without the chemokine. Increasing CXCL9 levels were associated with increasing hip fracture risk in men but not in women (pinteraction  = 0.002); comparing extreme quartiles, the OR (95% CI) in the highest quartile was 10.35 (1.90-56.39) in men (ptrend  = 0.002) but 1.46 (0.59-3.60) in women (ptrend  = 0.32). Adding CXCL9 to a prognostic model that already incorporated age and other risk factors improved the AUC (95% CI) from 0.65 (0.55-0.76) to 0.74 (0.65-0.83) for the predictive utility of hip fractures in men but not in women. Conversely, the association between CXCL10 and hip fracture risk was not statistically significant in either sex. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

NAFLD polygenic risk score and risk of hepatocellular carcinoma in an East Asian population.

It is difficult to identify people with nonalcoholic fatty liver disease (NAFLD) who are at high risk for developing hepatocellular carcinoma (HCC). A polygenic risk score (PRS) for hepatic fat (HFC-PRS) derived from non-Asians has been reported to be associated with HCC risk in European populations. However, population-level data of this risk in Asian populations are lacking. Utilizing resources from 24,333 participants of the Singapore Chinese Health Study (SCHS), we examined the relationship between the HFC-PRS and HCC risk. In addition, we constructed and evaluated a NAFLD-related PRS (NAFLD-PRS) with HCC risk in the SCHS. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of HCC incidence with both HFC-PRS and NAFLD-PRS. The HFC-PRS and NAFLD-PRS were highly correlated (Spearman r = 0.79, p < 0.001). The highest quartiles of both the HFC-PRS and the NAFLD-PRS were associated with significantly increased risk of HCC with HR of 2.39 (95% CI 1.51, 3.78) and 1.77 (95% CI 1.15, 2.73), respectively, compared with their respective lowest quartile. Conclusion: The PRS for hepatic fat content or NAFLD may be useful for assessing HCC risk in both Asian and European populations. The findings of this and prior studies support a potential causal role of genetically determined NAFLD in HCC development.

Diabetes and other vascular risk factors in association with the risk of lower extremity amputation in chronic limb-threatening ischemia: a prospective cohort study.

BACKGROUND: Patients with diabetes are at increased risk of developing chronic limb-threatening ischemia (CLTI) due to peripheral arterial disease, and this often results in lower extremity amputation (LEA). Little is known of the interaction between diabetes and other vascular risk factors in affecting the risk of CLTI. METHODS: We investigated the association of diabetes, and its interaction with hypertension, body mass index (BMI) and smoking, with the risk of LEA due to CLTI in the population-based Singapore Chinese Health Study. Participants were interviewed at recruitment (1993-1998) and 656 incident LEA cases were identified via linkage with nationwide hospital database through 2017. Multivariate-adjusted Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% CIs for the associations. RESULTS: The HR (95% CI) for LEA risk was 13.41 (11.38-15.79) in participants with diabetes compared to their counterparts without diabetes, and the risk increased in a stepwise manner with duration of diabetes (P for trend < 0.0001). Hypertension and increased BMI independently increased LEA risk in those without diabetes but did not increase the risk in those with diabetes (P for interaction with diabetes ≤ 0.0006). Conversely, current smoking conferred a risk increment of about 40% regardless of diabetes status. CONCLUSIONS: Although diabetes conferred more than tenfold increase in risk of LEA, hypertension and increased BMI did not further increase LEA risk among those with diabetes, suggesting a common mechanistic pathway for these risk factors. In contrast, smoking may act via an alternative pathway and thus confer additional risk regardless of diabetes status.

Composite dietary antioxidant index and the risk of colorectal cancer: Findings from the Singapore Chinese Health Study.

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.

Composite Score of Healthy Lifestyle Factors and the Risk of Pancreatic Cancer in a Prospective Cohort Study.

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.

Trends of cutaneous basal cell carcinoma, squamous cell carcinoma, and melanoma among the Chinese, Malays, and Indians in Singapore from 1968-2016.

BACKGROUND: Previous analysis showed that the incidence rates of skin cancer in Singapore increased from 1968 to 2006, especially among older Chinese, and particularly for basal cell carcinoma (BCC). OBJECTIVE: We updated the skin cancer incidence rates and time trends among the Chinese, Malays, and Indians in Singapore. METHODS: We analyzed the skin cancer incidence from the nationwide Singapore Cancer Registry from 1968 to 2016. RESULTS: Among 12,692 cases diagnosed from 1968 to 2016, there were 8367 (65.9%) cases of BCC, 3598 (28.3%) of squamous cell carcinoma (SCC), and 727 (5.8%) of melanoma. The mean ages at skin cancer diagnosis were 72.7 years for SCC, 66.9 years for BCC, and 59.8 years for melanoma. Sun-exposed areas accounted for 81.3% of BCCs, 61.6% of SCCs, and 26.7% of melanomas. The age-standardized incidence rate of cutaneous BCC was highest in the Chinese and increased by 2.5 fold over the study period, followed by a lower rate and slower increase in the Malays, and the lowest rate among the Indians. The SCC and melanoma incidences remained low in all 3 ethnicities during this study period. The Chinese had the highest relative risk for developing any skin cancer (P < .0001) compared with those of the Malays and Indians. Most cases of skin cancer were diagnosed at age ≥60, with men showing a higher incidence of SCC compared with that of women. CONCLUSION: Incidence rates of BCC have increased in Singapore, especially among the Chinese, in the past 5 decades. The SCC and melanoma incidence rates remained low and stable.

Quality Diet Index and Risk of Pancreatic Cancer: Findings from the Singapore Chinese Health Study.

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.

Food sources of dietary fibre and risk of total knee replacement related to severe osteoarthritis, the Singapore Chinese Health Study.

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.

Association between Pre-Diagnostic Serum Bile Acids and Hepatocellular Carcinoma: The Singapore Chinese Health Study.

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.

Low frequency variants associated with leukocyte telomere length in the Singapore Chinese population.

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.

Epidemiologic trends of infants with orofacial clefts in a multiethnic country: a retrospective population-based study.

Cleft births surveillance is essential in healthcare and prevention planning. Data are needed in precision medicine to target upstream management for at-risk individuals. This study characterizes Singapore's population-based orofacial cleft topography by ethnicity and gender, and establishes the cleft cohort's infant mortality rate. Data, in the decade 2003 to 2012, were extracted by the National Birth Defects Registry. Trend testing by linear regression was at p < 0.05 significance level. Prevalence per 10,000 for population-based cleft live births was 16.72 with no significant upward trend (p = 0.317). Prevalence rates were 8.77 in the isolated cleft group, 7.04 in the non-isolated cleft group, and 0.91 in the syndromic cleft group. There was significant upward trend in infants with non-isolated clefts (p = 0.0287). There were no significant upward trends in infants with isolated clefts and syndromic clefts. Prevalence rates were sexually dimorphic and ethnic-specific: male 17.72; female 15.78; Chinese group 17.17; Malay group 16.92; Indian group 10.74; and mixed ethnic origins group 21.73. The overall infant mortality rate (IMR) was 4.8% in the cohort of 608 cleft births, which was more than double the population-based IMR of 2.1% in the same period. Infants with non-isolated and syndromic clefts accounted for 96.6% of the deaths.

The association between dietary vitamin B12 and lung cancer risk: findings from a prospective cohort study.

BACKGROUND: Since previous epidemiological studies reported inconsistent associations between dietary vitamin B12 intake and lung cancer risk, more studies are warranted to clarify this association in different populations. METHODS: The association between dietary B12 intake and lung cancer risk was examined in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63 257 Singaporean Chinese men and women, 45-74 years of age at enrollment during 1993-1998 and were followed up for incidence of lung cancer for up to 25 years. Dietary vitamin B12 intake was derived from a validated food frequency questionnaire. Cox proportional hazard regression method was used to estimate hazard ratio and 95% confidence interval (CI) of lung cancer associated with dietary vitamin B12 intake with adjustment for multiple potential confounders. RESULTS: After a mean follow-up of 17.64 years, 2001 study participants developed lung cancer. High levels of vitamin B12 intake were associated with significantly increased risk of lung cancer (Ptrend = 0.03). Compared with the lowest quintile, hazard ratios (95% CIs) of lung cancer for quintile 2, 3, 4, and 5 of vitamin B12 intake were 1.09 (0.95-1.25), 1.11 (0.96-1.28), 1.11 (0.97-1.29) and 1.18 (1.03-1.35), respectively. This positive association was more apparent in men than in women, in adenocarcinoma patients, or in participants with equal or less than 2 years follow-up than those with longer duration of follow-up. CONCLUSION: Higher intake of dietary vitamin B12 was associated with increased risk of lung cancer. This highlights the potential harmful effect of vitamin B12 supplementation for lung cancer.

Leukocyte telomere length, cancer incidence and all-cause mortality among Chinese adults: Singapore Chinese Health Study.

Telomeres play a key role in chromosomal maintenance and stability. To date, few studies have investigated the association of leukocyte telomere length with risk of cancer incidence and all-cause mortality in a large prospective cohort, particularly of the Asian population. Relative telomere lengths in genomic DNA from peripheral blood samples were quantified using a validated quantitative real-time PCR among 26 540 middle-aged or older Chinese adults. Hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer and deaths by quintiles of telomere length were calculated using the Cox proportional hazards regression method with adjustment for age, sex and other potential confounders. After baseline blood collection, 4353 persons developed cancer and 7609 died. Participants with the longest decile of telomeres had a 26% (95% CI: 11%-44%) higher risk of total cancer incidence compared to the shortest decile after controlling for age, sex and other potential founders (Ptrend < .0001). In contrast, longer telomeres were associated with lower risk of all-cause mortality (HR = 0.93; 95% CI: 0.84-1.03), noncancer death (HR = 0.81; 95% CI: 0.71-0.92), specifically, death from chronic obstructive pulmonary disease and pneumonia (HR = 0.79, 95% CI: 0.70-0.89) and digestive diseases (HR = 0.60, 95% CI: 0.42-0.88). Our findings demonstrated that longer telomeres are associated with increased risk of cancer development overall and several common cancer types including breast, rectal, prostate, pancreatic cancer and lung adenocarcinoma. Our study also confirmed that longer telomeres are associated with a reduced risk of noncancer related death.

Composite Score of Healthy Lifestyle Factors and Risk of Hepatocellular Carcinoma: Findings from a Prospective Cohort Study.

BACKGROUND: While the associations between individual lifestyle factors and risk of hepatocellular carcinoma (HCC) have been described previously, their combined impact on HCC risk is unknown. METHODS: The association of a composite score of healthy lifestyle factors, including body mass index, alcohol consumption, cigarette smoking, alternative Mediterranean diet, and sleep duration, and HCC risk was examined in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63,257 Chinese men and women. Cox proportional hazard regression method was used to estimate HR and its 95% confidence interval (CI). Conditional logistic regression method was used to evaluate this composite lifestyle score-HCC risk association among a subset of individuals who tested negative for hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody. RESULTS: After a mean follow-up of 17.7 years, 561 participants developed HCC. Individuals with higher composite scores representing healthier lifestyles (range 0-8) were at significantly lower risk of HCC. Compared with the lowest composite score category (0-4), the HRs (95% CIs) for the composite scores of 5, 6, 7, and 8 were 0.67 (0.62-0.85), 0.61 (0.48-0.77), 0.49 (0.37-0.65), and 0.13 (0.06-0.30), respectively (P trend < 0.0001). A similar inverse association was observed in participants with negative HBsAg and anti-hepatitis C virus (HCV)-negative serology (HR, 0.38; 95% CI, 0.19-0.79; for the highest vs. the lowest category of the composite scores; P trend = 0.001). CONCLUSIONS: Healthy lifestyles protect against HCC development, especially for individuals without hepatitis B virus and HCV infections. IMPACT: This study highlights the importance of a comprehensive lifestyle modification strategy for HCC primary prevention.