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 hazard ratios (HRs) and 95% confidence intervals (CIs) 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; P-trend=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.

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.

ScRNA-Seq Reveals a Distinct Osteogenic Progenitor of Alveolar Bone

The metabolism and remodeling of alveolar bone are the most active among the whole skeletal system, which is related to the biological characteristics and heterogeneity of the bone mesenchymal stromal cells (MSCs). However, there is a lack of systematic description of the heterogeneity of MSC-derived osteoblastic lineage cells as well as their distinct osteogenic differentiation trajectory of alveolar bone. In this study, we constructed a single-cell atlas of the mouse alveolar bone cells through single-cell RNA sequencing (scRNA-seq). Remarkably, by comparing the cell compositions between the alveolar bone and long bone, we uncovered a previously undescribed cell population that exhibits a high expression of protocadherin Fat4 (Fat4⁺ cells) and is specifically enriched around alveolar bone marrow cavities. ScRNA-seq analysis indicated that Fat4⁺ cells may initiate a distinct osteogenic differentiation trajectory in the alveolar bone. By isolating and cultivating Fat4⁺ cells in vitro, we demonstrated that they possess colony-forming, osteogenic, and adipogenic capabilities. Moreover, FAT4 knockdown could significantly inhibit the osteogenic differentiation of alveolar bone MSCs. Furthermore, we revealed that the Fat4⁺ cells exhibit a core transcriptional signature consisting of several key transcription factors, such as SOX6, which are involved in osteogenesis, and further demonstrated that SOX6 is required for the efficient osteogenic differentiation of the Fat4⁺ cells. Collectively, our high-resolution single-cell atlas of the alveolar bone reveals a distinct osteogenic progenitor that may contribute to the unique physiological characteristics of alveolar bone.

Osteoblastic RAR Inhibition Causes VAD-Like Craniofacial Skeletal Deformity

Retinoid signaling disorders cause craniofacial deformity, among which infants with maternal vitamin A deficiency (VAD) exhibited malformation of the eye, nose, palate, and parietal and jaw bone. Previous research uncovered the pathogenesis of eye defect and cleft palate of VAD in mice, but the studies on craniofacial skeletal deformity met obstacles, and the cell/lineage and underlying mechanism remain unclear. The retinoic acid receptor (RAR) is the key transcription factor in retinoid signaling, but individual knockout cannot simulate pathway inhibition. Here, we conditionally expressed dominant-negative RARα mutation (dnRARα) in osteoblasts to specifically inhibit the transcription activity of RAR in mice, which mimics the craniofacial deformities caused by VAD in clinical cases: hypomineralization of cranial bones, mandibular deformity, and clavicular hypoplasia. Furthermore, we performed 3-dimensional reconstruction based on micro-computed tomography and confirmed the abnormalities in the shape, size, and ossification of craniofacial bones due to osteoblastic RAR inhibition. Histological analysis indicated that inhibition of RAR in osteoblasts impaired both bone formation and bone resorption, which was confirmed by transcriptome sequencing of the calvaria. Furthermore, mechanism investigation showed that inhibition of RAR in osteoblasts directly decreased osteoblast differentiation in a cell-autonomous manner by impairing osteogenic gene transcription and also inhibited osteoclast differentiation via osteoblast-osteoclast crosstalk by impairing Rankl transcription. In summary, osteoblastic RAR activity is critical to craniofacial skeletal development, and its dysfunction leads to skeletal deformities mimicking VAD craniofacial defects, providing a new insight for VAD pathogenesis.

Abstract 3015: Soluble CD137 and risk of hepatocellular carcinoma: nested case-control studies in cohorts in Shanghai and Singapore

Background: Chronic inflammation plays a significant role in hepatocellular carcinoma (HCC). With rising incidence and poor prognosis of HCC, identifying relatively less invasive biomarkers, especially inflammatory ones, may improve the assessment and stratification of HCC risk. The objective of our studies was to assess if CD8+ T cell cytokines in pre-diagnostic serum are associated with risk of HCC development.

Methods: We conducted two parallel case-control studies of HCC nested within the Shanghai Cohort Study (SCS) and the Singapore Chinese Health Study (SCHS), two prospective cohorts of 81,000 individuals with 25+ years of follow-up. The serum concentrations of five CD8+ T cell cytokines ─ soluble CD137 (sCD137), soluble Fas (sFas), perforin, macrophage inflammatory protein 1-beta (MIP-1β), and tumor necrosis factor alpha (TNF-α) ─ were determined using Luminex bead-based immunoassay on 315 HCC cases and 315 individually matched controls in the SCS, and on 197 HCC case-control pairs in the SCHS. Conditional logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for HCC with elevated levels of cytokines with adjustment for body mass index, alcohol drinking, cigarette smoking, seropositivity of hepatitis surface antigen (HBsAg), and history of diabetes.

Results: sCD137 levels were statistically significantly higher in HCC cases than controls in both cohorts. Compared with the 1st quartile (Q1) of sCD137, multivariable-adjusted ORs (95% CI) of HCC for the 4th quartile (Q4) were 3.8 (1.7-8.3) in the SCS and 3.5 (1.4 -8.5) in the SCHS (both Ptrend’s < 0.001). Among HBsAg-negative individuals, ORs (95% CIs) for Q2, Q3, & Q4 of sCD137 were 2.7 (1.5-4.9), 2.7 (1.4-5.0), and 4.5 (2.4-8.5), respectively, compared with Q1 (Ptrend < 0.001) in both SCS and SCHS combined. The corresponding ORs (95% CIs) among HBsAg- positive individuals were 21.0 (9.3-47.6), 34.1 (13.8-84.2), and 56.7 (23.3-137.9), respectively, with a P=0.095 for multiplicative interaction. The sCD137-HCC risk association remained constant over different time periods from blood draw to HCC diagnosis: ORs (95% CIs) for Q4 vs. Q1 were 4.7 (1.2-17.5) for <5 years, 3.7 (1.3-10.6) for 5-10 years, and 3.94 (1.6-9.5) for more than 10 years between blood collection and cancer diagnosis. sFas was positively associated with HCC risk in the SCHS but not in the SCS. There was no statistically significant association for perforin, MIP-1β, or TNF-α with HCC risk in either cohort.

Conclusion: These novel and validated findings demonstrated that serum sCD137 levels were significantly elevated many years prior to HCC diagnosis, and had a potential synergistic effect with chronic viral infection on the HCC risk. sCD137 may be developed as a immune monitoring biomarker for risk stratification and assessment, which can lead to early diagnosis and improve prognosis of HCC patients.

Citation Format: Claire E. Thomas, Jennifer J. Adibi, Allison L. Kuipers, Brenda Diergaarde, Hung N. Luu, Aizhen Jin, Woon-Puay Koh, Yu-Tang Gao, Jennifer Adams-Haduch, Renwei Wang, Anna Lokshin, Jaideep Behari, Jian-Min Yuan. Soluble CD137 and risk of hepatocellular carcinoma: nested case-control studies in cohorts in Shanghai and Singapore [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3015.

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-1β), 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.

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 (p_interaction  = 0.002); comparing extreme quartiles, the OR (95% CI) in the highest quartile was 10.35 (1.90-56.39) in men (p_trend  = 0.002) but 1.46 (0.59-3.60) in women (p_trend  = 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).

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 (HR_{Q4 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.

Abstract 3667: Composite dietary antioxidant index and the risk of pancreatic cancer: Findings from a prospective cohort study

Background. Composite Dietary Antioxidant Index (CDAI) is a summary score derived from statistical modeling that ranks an individual’s dietary intake of antioxidants in relation to the overall mean of the study population. Antioxidants may offer a beneficial effect on reducing the risk of pancreatic cancer. No prospective epidemiological study has investigated the association between food-based CDAI (fCDAI) and pancreatic cancer risk.

Methods. The fCDAI score was calculated based on dietary intakes of vitamins A, C, and E, manganese, selenium, and zinc from food but not from dietary supplements, for each participant of the Singapore Chinese Health Study, a population-based prospective epidemiological cohort study consisting of 61,321 Chinese men and women in Singapore aged 45-74 years at baseline enrollment during 1993-1998. Intake of antioxidants was derived from self-reported consumption of food items using a validated semi-quantitative food frequency questionnaire and the Singapore Food Composition Table. Incident cases of cancer, including pancreatic cancer, and death were identified through the linkage analysis with the nationwide Singapore Cancer Registry and the Singapore Registry of Birth and Death, respectively. The Cox proportional hazard regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of pancreatic cancer associated with higher quartiles of fCDAI relative to the lowest quartile with adjustment for multiple potential confounders, including age, sex, dialect group, level of education, smoking status, alcohol consumption, a history of diabetes, sleep duration, physical activity, year of enrollment, and total energy intake.

Results. Overall, 311 participants who were free of cancer at baseline developed pancreatic cancer during an average of 17.7 years of follow-up after baseline assessment of food consumption. Compared with the lowest quartile, the multivariable-adjusted HR of pancreatic cancer for the highest quartile of fCDAI was 0.54 (95% CI: 0.31-.91, P=0.02). This inverse association between the fCDAI and pancreatic cancer risk was more apparent in overweight/obese subjects (HRQ4vsQ1=0.28, 95% CI: 0.13-0.60, Ptrend=0.02), or those without a history of diabetes (HRQ4vsQ1=0.50, 95% CI: 0.29-0.88, Ptrend=0.04). No association was observed between CDAI derived from dietary supplements and the risk of pancreatic cancer.

Conclusions. The inverse association between fCDAI and pancreatic cancer risk supports the notion that overall dietary antioxidants may provide a beneficial effect against the development of pancreatic cancer, specifically overweight/obese individuals and those free of diabetes who may have a long-term persistent dietary pattern. These results highlight the importance of promoting healthy eating for the primary prevention of pancreatic cancer.

Citation Format: Pedram Paragomi, Renwei Wang, Aizhen Jin, Yi-Chuan Yu, Randall E. Brand, Li-Ting Sheng, An Pan, Woon-Puay Koh, Jian-Min Yuan, Hung Luu. Composite dietary antioxidant index and the risk of pancreatic cancer: Findings from a prospective cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3667.

Abstract 3666: Dietary potassium and risk of colorectal cancer: Findings from the Singapore Chinese Cohort Study

Background: Colorectal cancer (CRC) is a commonly diagnosed subtype of cancer with a high mortality rate. Potassium is a necessary trace element in the human boy and is derived mainly from diet. Prior studies found high intakes of potassium was inversely associated with colorectal cancer occurrence in Western population. No such effort has been made in Asian population. Methods: We examined the associations for dietary potassium with the risk of CRC in the Singapore Chinese Health Study (SCHS), a population-based prospective cohort study that includes 61,321 Chinese men and women in Singapore who were 45-74 years of age at baseline. Daily intake of potassium was derived from the self-reported intake of pre-defined food items using a validated semi-quantitative food frequency questionnaire (FFQ) at baseline according to the Singapore Food Composition Table. Cox proportional hazard regression model was used to estimate the hazard ratios (HRs) and respective 95% confidence intervals (CIs) for CRC associated with higher quartile of potassium compared with the lowest quartile with adjustment for potential confounders. Results: After an average of 17.5 years of follow-up, 2,140 participants developed CRC. Dietary potassium was inversely associated with CRC risk. The multivariable-adjusted HR of CRC for the highest relative to the lowest quarter of daily potassium intake was 0.85 (95% CI 0.75-0.96, Ptrend=0.03). The inverse association between high intake of potassium and CRC risk was more apparent among participants with body mass index (BMI) ≥ 23 kg/m2 (HRQ4vsQ1=0.75, 95% CI: 0.63-0.89; Ptrend=0.003) and those with history of type 2 diabetes (HRQ4vsQ1=0.65, 95% CI: 0.42-1.00; Ptrend=0.36).

Conclusions: In a large population-based prospective cohort study of more than 61,000 Chinese Singaporeans, we found inverse associations between dietary potassium intake and CRC risk. Future studies are warranted to elucidate the biological mechanism for the protective effect of potassium on the development of CRC.

Citation Format: Hung N. Luu, Pedram Paragomi, Yi-Chuan Yu, Aizhen Jin, Renwei Wang, Robert E. Schoen, Woon-Puay Koh, Jian-Min Yuan. Dietary potassium and risk of colorectal cancer: Findings from the Singapore Chinese Cohort Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3666.

Abstract 735: Low-carbohydrate diet score and the risk of colorectal cancer: Findings from a prospective cohort study

Background. Colorectal cancer (CRC) is a commonly diagnosed cancer. Glucose intake enhances the secretion of insulin, may contribute to cell growth and proliferation, leading to CRC development. Epidemiologic studies have shown that individuals with diabetes history are at increased risk of CRC. A low-carbohydrate diet, represented by a low-carbohydrate diet (LCD) score, may reduce the risk of diabetes. Yet, little is known about the association between LCD scores and the risk of CRC.

Methods. We evaluated the associations between LCD and CRC risk in the Singapore Chinese Health Study, a population-based prospective cohort study that includes 61,321 Chinese men and women in Singapore who were 45-74 years old at enrollment. Food and dietary supplement consumption were assessed by a validated semi-quantitative food frequency questionnaire. Participants were assigned a score from 0 to 10 according to their rankings by daily intake of calories from carbohydrates, fat and protein, respectively. A score of 0 was assigned to a subject ranked in the highest one-eleventh of calorie intake from carbohydrates or in the lowest one-eleventh of calories from fat or protein, respectively. In contrast, a score of 10 was given to each subject in the lowest one-eleventh of carbohydrate intake or the highest one-eleventh of fat or protein intake. The LCD score for each subject was the sum of the 3 individual ranking scores. The highest possible value was 30, which represented the lowest carbohydrate intake and the highest fat and protein. In addition, animal-based and plant-based LCDs were similarly created from the daily consumption of calories from animal or plant protein and fat, respectively, as well as carbohydrates. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs) for CRC according to higher quartiles of LCD scores with adjustment for potential confounders.

Results. After an average of 17.5 years of follow-up, 2,140 participants developed CRC. Overall, there was a null association between total LCD and CRC risk. A moderate positive association was found for animal-based LCD with CRC risk. The multivariable-adjusted HRs(95%CIs) for CRC in quartiles 2, 3, and 4 of animal-based LCD were 1.12(0.99-1.26), 1.18(1.04-1.33), and 1.11(0.98-1.25)(Ptrend=0.06) compared with the lowest quartile. There were no statistically significant differences in the animal-based LCD and CRC risk in subgroups stratified by sex, body mass index, smoking status, and history of type 2 diabetes.

Conclusions. This large population-based prospective cohort study shows that a high animal-based LCD score, which represented low intake of carbohydrates and high intake of animal protein and fat, was associated with ~10% increased risk of CRC. Our findings suggest that replacing low-carbohydrate food with animal-based food may increase the risk of developing CRC.

Citation Format: Yi-Chuan Yu, Pedram Paragomi, Aizhen Jin, Renwei Wang, Robert E. Schoen, Woon-Puay Koh, Jian-Min Yuan, Hung N. Luu. Low-carbohydrate diet score and the risk of colorectal cancer: Findings from a prospective cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 735.

Abstract 2260: Non-alcoholic fatty liver disease polygenic risk score and risk of hepatocellular carcinoma in an East Asian population

Purpose: It is difficult to identify people with non-alcoholic fatty liver disease (NAFLD) who are at high risk for the development of hepatocellular carcinoma (HCC). A polygenic risk score (PRS) for hepatic fat derived from non-Asians has been reported to be associated with HCC risk in European populations. However, population level data of this risk in non-European populations are lacking.

Methods: Utilizing resources from the Singapore Chinese Health Study (SCHS), we examined the relationship between the previously published hepatic fat PRS (HFC-PRS) and HCC risk. We also constructed and evaluated a NAFLD-related PRS (NAFLD-PRS); the final version included SNPs in similar gene regions as the HFC-PRS but weighted by effect estimates for NAFLD among those with East Asian ancestry. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) of HCC incidence with both HFC-PRS and NAFLD-PRS.

Results: The HFC-PRS and NAFLD-PRS were highly correlated (Spearman r = 0.79, P &lt; 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 to their respective lowest quartile.

Conclusion: The HFC-PRS and the NAFLD-PRS may both be useful in stratifying Asian populations according to their risk of HCC. In addition, the association between the NAFLD-PRS, derived from East Asians, and HCC risk suggests a potential causal role for NAFLD in the development of HCC in this population.

Citation Format: Claire E. Thomas, Brenda Diergaarde, Allison L. Kuipers, Jennifer J. Adibi, Hung N. Luu, Xuling Chang, Rajkumar Dorajoo, Chew-Kiat Heng, Chiea-Chuen Khor, Renwei Wang, Aizhen Jin, Woon-Puay Koh, Jian-Min Yuan. Non-alcoholic fatty liver disease polygenic risk score and risk of hepatocellular carcinoma in an East Asian population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2260.

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.

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 (P_trend  = .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.

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 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.

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.

Abstract 756: The association between serum serine and glycine and related-metabolites with pancreatic cancer in two prospective cohort studies

Background. Serine and glycine play an important role in the folate-dependent one-carbon metabolism. The metabolism of serine and glycine has been shown to be associated with cancer cell proliferation. No prior epidemiologic study has investigated the associations for serum levels of serine, glycine and their related-metabolites with pancreatic cancer risk.

Methods. Two parallel nested case-control studies derived from the Shanghai Cohort Study (with 129 cases and 258 controls) and from the Singapore Chinese Health Study (with 58 cases and 104 controls), respectively, were conducted to examine these associations. Conditional logistic regression method was used to evaluate the associations between serine, glycine and related-matabolites with pancreatic cancer risk, adjusting for potential confounders (i.e., level of education, body mass index, smoking status, alcohol consumption, history of diabetes, serum cotinine concentration, serum pyridoxal 5'-phosphate concentration (PLP), and estimated glomerular filtration rate (eGFR)).

Results. In the two studies combined data, odds ratios and 95% confidence intervals of pancreatic cancer for the highest quartile of serine and glycine were 0.42 (0.23-0.78) and 0.39 (0.21-0.72), respectively, compared with the lowest quartile. No significant association with risk of pancreatic cancer was observed for other serine- or glycine related metabolites including cystathionine, cysteine, and sarcosine.

Conclusion. The novel observation for a statistically significant inverse association for serum serine and glycine with risk of pancreatic cancer supports a protective role of these metabolites in the folate pathway against the development of pancreatic cancer in humans. With the experimental data showing the impact of serine and glycine on gut microbiota composition, [YJM1] our findings suggest that the alteration of gut microbiota may play a contributing role in reducing the risk of pancreatic cancer.

Funding: The Singapore Chinese Health Study was supported by the National Institutes of Health (NIH) of the United States (grants # R01 CA144034 and UM1 CA182876). HN Luu was partially supported by the University of Pittsburgh Medical Center Hillman Cancer Center start-up grant. P Paragomi was supported by the NIH T32CA186873 training grant in cancer epidemiology and prevention. W-P Koh was partially supported by the National Medical Research Council, Singapore (NMRC/CSA/0055/2013).

Citation Format: Hung N. Luu, Renwei Wang, Pedram Paragomi, Joyce Y. Huang, Lesley M. Butler, Øivind Midttun, Arve Ulvik, Aizhen Jin, Yu-Tang Gao, Per M. Ueland, Woon-Puay Koh, Jian-Min Yuan. The association between serum serine and glycine and related-metabolites with pancreatic cancer in two prospective cohort studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 756.

Abstract 748: Conjugated primary bile acids as a biomarker for hepatocellular carcinoma risk in two prospective cohorts

Background: Incidence rates of hepatocellular carcinoma (HCC) has been increasing for several decades in the U.S. Non-alcoholic liver disease (NAFLD) increasingly plays a role in the rising rate of HCC. Experimental data have shown that bile acids, which play key roles in the host-gut microbiota co-metabolism, contribute to the development of NAFLD and HCC. We propose to comprehensively examine the associations of bile acids with risk of HCC in two cohorts.

Methods: Thirty-five bile acids were quantified using the state-of-the-art ultraperformance liquid chromatography triple-quadrupole mass spectrometry assays in serum samples collected, on average, five years prior to diagnosis of 197 HCC and the same number of individually matched controls from the Singapore Chinese Health Study and the Shanghai Cohort Study. Conditional logistic regression was used to assess the associations for major bile acids and their conjugates, and bile acid ratios with the risk of HCC.

Results: Total primary bile acids were significantly elevated whereas the ratio of secondary bile acids over primary bile acids were significantly lower in HCC cases than controls in both cohorts (P's ≤ 0.001). Doubling of tauro- vs. glyco-conjugates of all bile acids, primary bile acids, and specifically chenodeoycholic acid resulted in an increase in HCC risk of 44, 48, and 34% (P = 0.004, &lt;0.001, 0.001) respectively after adjustment for potential confounders.

Conclusion: Primary bile acids, especially tauro-conjugated bile acids were strongly associated with increased risk of HCC risk whereas the secondary vs. primary bile acids ratios were associated with decreased risk of HCC.

Citation Format: Claire Elizabeth Thomas, Hung Luu, Renwei Wang, Guoxiang Xie, Jennifer Adams-Haduch, Aizhen Jin, Woon-Puay Koh, Wei Jia, Jaideep Behari, Jian-Min Yuan. Conjugated primary bile acids as a biomarker for hepatocellular carcinoma risk in two prospective cohorts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 748.

Abstract 854: Dietary quality indexes and risk of pancreatic cancer: Findings from a prospective cohort study

Background. Dietary quality index represents a long-term dietary intake of nutritive and non-nutritive compounds. Therefore, it would be more informative for evaluating the association between dietary intake and health outcomes, including pancreatic cancer, in different populations with distinct dietary habits and patterns. Limited research has been conducted on the effect of dietary quality index (DQI) on pancreatic cancer risk in Asian populations.

Methods. Using data from Singapore Chinese Health Study, a prospective cohort study of 63,257 Chinese men and women aged 45-74 at enrollment during 1993-1998, we created four diet-quality index scores: the Alternative Health Eating Index-2010 (AHEI-2010), alternate Mediterranean Diet (aMED), Dietary Approaches to Stop Hypertension (DASH) and Heathy Diet Indicator (HDI) based on the baseline information collected using validated semi-quantitative food frequency questionnaire. After a mean 17 years of follow-up, 316 participants developed pancreatic cancer. The Cox proportional hazard regression method was used to estimate hazard ratio (HR) and 95% confidence interval (CI) for pancreatic cancer in relation to different levels of these DQI scores.

Results. High scores of AHEI-2010, aMED and DASH were associated with lower risk of pancreatic cancer (all Ptrend&lt;0.05). Compared with the lowest quartile, HRs (95% CIs) of pancreatic cancer for the highest quartiles of AHEI-2010, aMED and DASH were 0.65 (0.46-0.90), 0.60 (0.41-0.89), and 0.69 (0.48-0.98), respectively, after adjustment for age, sex, body mass index, alcohol intake, tobacco smoking, and history of diabetes. We did not find a discernable heterogeneity in these dietary quality indexes-pancreatic cancer risk associations by body mass index levels or status of diabetes or smoking.

Conclusion. High quality diet is significantly associated with reduced risk of pancreatic cancer. The consistent results across different DQIs support the notion that adherence to a healthy diet may lower the risk of pancreatic cancer, suggesting that dietary modification may be a cost-effective approach for primary prevention of pancreatic cancer.

Funding: The Singapore Chinese Health Study was supported by the National Institutes of Health (NIH) of the United States (grants # R01 CA144034 and UM1 CA182876). HN Luu is partially supported by the University of Pittsburgh Medical Center Hillman Cancer Center start-up grant. P Paragomi was supported by the NIH T32CA186873 training grant in cancer epidemiology and prevention; W-P Koh was partially supported by the National Medical Research Council, Singapore (NMRC/CSA/0055/2013).

Citation Format: Hung N. Luu, Pedram Paragomi, Aizhen Jin, Renwei Wang, Nithya Neelakantan, Rob M. van Dam, Randall E. Brand, Woon-Puay Koh, Jian-Min Yuan. Dietary quality indexes and risk of pancreatic cancer: Findings from a prospective cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 854.

FOXO3 Mediates Tooth Movement by Regulating Force-Induced Osteogenesis

The high prevalence of malocclusion and dentofacial malformations means that the demand for orthodontic treatments has been increasing rapidly. As the biological basis of orthodontic treatment, the mechanism of mechanical force-induced alveolar bone remodeling during orthodontic tooth movement (OTM) has become the key scientific issue of orthodontics. It has been demonstrated that bone mesenchymal stem cells (BMSCs) are crucial for bone remodeling and exhibit mechanical sensing properties. Mechanical force can promote osteoblastic differentiation of BMSCs and osteogenesis, but the key factor that mediates mechanical force-induced osteogenesis during OTM remains unclear. In this study, by performing reverse-phase protein arrays on BMSCs exposed to mechanical force, we found that the expression level of forkhead box O3 (FOXO3) was significantly upregulated during the mechanical force-induced osteoblastic differentiation of BMSCs. The number of FOXO3-positive cells was consistently higher on the OTM side as compared with the control side and accompanied by the enhancement of osteogenesis. Remarkably, inhibiting FOXO3 with repaglinide delayed OTM by severely impairing mechanical force-induced bone formation in vivo. Moreover, knockdown of FOXO3 effectively inhibited the mechanical force-induced osteoblastic differentiation of BMSCs, whereas the overexpression of FOXO3 enhanced this effect. Mechanistically, we revealed a novel regulatory model in which FOXO3 promoted osteocalcin transcription by activating its promoter in cooperation with runt-related transcription factor 2 (RUNX2). We collectively obtained the first evidence that FOXO3 is critical for OTM, where it responds to mechanical force and directly regulates downstream osteoblastic differentiation in an efficient manner.

POS1095 FOOD SOURCES OF DIETARY FIBRE AND RISK OF TOTAL KNEE REPLACEMENT RELATED TO SEVERE OSTEOARTHRITIS, THE SINGAPORE CHINESE HEALTH STUDY

Background:

Although fibre intake was inversely associated with the risk of symptomatic knee osteoarthritis (KOA) in a US study, this association was partially confounded by lower body mass index (BMI) in those with higher fibre intake.

Objectives:

We evaluated the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe 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 semi-quantitative food frequency questionnaire, together with BMI and lifestyle factors. Incident TKR cases were identified via record linkage with nationwide hospital discharge database through 2017. We used multivariable Cox regression models to compute hazard ratio (HR) and the corresponding 95% confidence interval (CI) for risk of TKR.

Results:

There were 2,816 cases of incident TKR due to severe KOA. Total fibre intake at baseline was not associated with risk of TKR after adjustment for confounders. Among the food sources of fibre, higher intake of legumes was associated with lower risk of TKR in dose-dependent manner; compared with those having the lowest quartile intake, HR (95% CI) was 0.86 (0.76, 0.96) for the highest quartile (p for trend = 0.004). This association was consistent after including BMI in the model, and homogenous across BMI categories. The consumption of other fibre sources, namely grain products, nuts and seeds, soy food, fruits and vegetables, was not associated with 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 in pathogenesis or progression of KOA.

Table 1.

Hazard ratios (95% confidence intervals) for risk of total knee replacement according to intake of fibre (only shown total fibre and legumes): The Singapore Chinese Health Study (1993-2017).

Quartiles of energy-adjusted food intakeQ1Q2Q3Q4p for trend 1Total fibreMedian, g/day8.559.4312.1917.70Cases/ person-years528/ 275,050712/ 280,456767/ 284,394809/ 287,955Multivariate Model 11.001.08 (0.96, 1.21)1.12 (1.00, 1.26)1.18 (1.05, 1.32)0.003Multivariate Model 21.001.06 (0.95, 1.19)1.09 (0.97, 1.22)1.11 (0.99, 1.24)0.088LegumesMedian, g/day0.110.432.117.01Cases/ person-years638/ 280,170754/ 278,001756/ 280,407668/ 289,275Multivariate Model 11.000.97 (0.87, 1.09)0.95 (0.84, 1.06)0.84 (0.76, 0.94)<0.001Multivariate Model 21.000.98 (0.87, 1.09)0.94 (0.84, 1.06)0.86 (0.77, 0.96)0.004Multivariate Model 31.000.98 (0.87, 1.09)0.95 (0.84, 1.06)0.86 (0.76, 0.96)0.004

1Linear trend was tested by assigning to participants the median value of the quartile and treating this as a continuous variable. 2 The grain products included noodles and pasta, rice, bread and pancakes, breakfast cereals, biscuits and crackers.

Multivariate model 1: adjusted for age at interview, sex, year of interview, total energy intake, dialect, education level

Multivariate model 2: model 1 plus BMI, sitting duration, sleep, physical activity, smoking, history of hypertension, diabetes, coronary artery disease and stroke.

Multivariate model 3: model 2 plus grain products, legumes, nuts and seeds, soy food, fruits and vegetables.

Q = quartile

Disclosure of Interests:

None declared.

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.

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.

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.

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.

Quality diet indexes and risk of hepatocellular carcinoma: Findings from the Singapore Chinese Health Study

There is limited research on the effect of dietary quality on hepatocellular carcinoma (HCC) risk in populations with relatively high risk of HCC. Using data from Singapore Chinese Health Study, a prospective cohort study, of 63 257 Chinese aged 45 to 74, we assessed four diet-quality index (DQI) scores: the Alternative Health Eating Index-2010 (AHEI-2010), Alternate Mediterranean Diet (aMED), Dietary Approaches to Stop Hypertension (DASH) and Heathy Diet Indicator (HDI). We identified 561 incident HCC cases among the cohort participants after a mean of 17.6 years of follow-up. Cox proportional hazard regression model was used to estimate hazard ratio (HR) and 95% confidence interval (CI) for HCC in relation to these DQI scores. Unconditional logistic regression method was used to evaluate the associations between DQIs and HCC risk among a subset of individuals who tested negative for hepatitis B surface antigen (HBsAg). High scores of AHEI-2010, aMED and DASH, representing higher dietary quality, were associated with lower risk of HCC (all P_trend  < .05). Compared with the lowest quartile, HRs (95% CIs) of HCC for the highest quartile of AHEI-2010, aMED and DASH were 0.69 (0.53-0.89), 0.70 (0.52-0.95) and 0.67 (0.51-0.87), respectively. No significant association between HDI and HCC risk was observed. Among HBsAg-negative individuals, similar inverse associations were observed, and the strongest inverse association was for aMED (HR_Q4vsQ1 = 0.46, 95% CI: 0.23-0.94, P_trend = .10). These findings support the notion that adherence to a healthier diet may lower the risk of HCC, suggesting that dietary modification may be an effective approach for primary prevention of HCC.

Dietary Antioxidants and Risk of Parkinson's Disease in the Singapore Chinese Health Study

BACKGROUND

Despite experimental evidence implicating oxidative stress in the pathogenesis of PD, epidemiological studies have provided inconsistent associations between dietary antioxidants and risk of developing PD. Furthermore, no study has been done in any Asian population.

OBJECTIVES

We examined the associations for intake levels of dietary carotenoids (α-carotene, β-carotene, lycopene, β-cryptoxanthin, and lutein) and vitamins (vitamin A, C and E) and the risk of developing PD.

METHODS

We used data from the Singapore Chinese Health Study, a population-based prospective cohort of 63,257 men and women aged 45 to 74 years during enrollment in 1993-1998. Antioxidant intake was derived from a validated semiquantitative food frequency questionnaire. Incident cases were identified through follow-up interviews, hospital records, or PD registries through 31 July 2018. Hazard ratios and corresponding 95% confidence intervals were derived from multivariable Cox proportional hazard regression models with adjustment for other lifestyle and dietary factors.

RESULTS

During an average 19.4 years of follow-up, 544 incident PD cases were identified. No association was found for dietary carotenoids, individually or summed. Hazard ratio comparing highest to lowest quartile for total carotenoids was 0.98 (95% confidence interval: 0.76-1.28; Ptrend = 0.83). There were also no clear dose-dependent associations of dietary vitamins A, C, and E with risk of developing PD (all Ptrend  ≥ 0.10). Sensitive analyses with lag time and excluding supplement use did not materially alter results.

CONCLUSIONS

Intake of dietary antioxidants, such as carotenoids and vitamins, was not associated with the risk of developing PD in Singaporean Chinese. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A prospective evaluation of serum methionine-related metabolites in relation to pancreatic cancer risk in two prospective cohort studies

Deficiencies in methyl donor status may render DNA methylation changes and DNA damage, leading to carcinogenesis. Epidemiological studies reported that higher dietary intake of choline is associated with lower risk of pancreatic cancer, but no study has examined the association of serum choline and its metabolites with risk of pancreatic cancer. Two parallel case-control studies, one nested within the Shanghai Cohort Study (129 cases and 258 controls) and the other within the Singapore Chinese Health Study (58 cases and 104 controls), were conducted to evaluate the associations of baseline serum concentrations of choline, betaine, methionine, total methyl donors (i.e., sum of choline, betaine and methionine), dimethylglycine and trimethylamine N-oxide (TMAO) with pancreatic cancer risk. In the Shanghai cohort, odds ratios and 95% confidence intervals of pancreatic cancer for the highest quartile of choline, betaine, methionine, total methyl donors and TMAO were 0.27 (0.11-0.69), 0.57 (0.31-1.05), 0.50 (0.26-0.96), 0.37 (0.19-0.73) and 2.81 (1.37-5.76), respectively, compared to the lowest quartile. The corresponding figures in the Singapore cohort were 0.85 (0.23-3.17), 0.50 (0.17-1.45), 0.17 (0.04-0.68), 0.33 (0.10-1.16) and 1.42 (0.50-4.04). The inverse associations of methionine and total methyl donors including choline, betaine and methionine with pancreatic cancer risk in both cohorts support that DNA repair and methylation play an important role against the development of pancreatic cancer. In the Shanghai cohort, TMAO, a gut microbiota-derived metabolite of dietary phosphatidylcholine, may contribute to higher risk of pancreatic cancer, suggesting a modifying role of gut microbiota in the dietary choline-pancreatic cancer risk association.

Abstract 4647: Diet quality indexes and risk of hepatocellular carcinoma: Findings from the Singapore Chinese Health Study

Background. There is a limited research on the association between combined dietary measures and liver cancer risk. We investigated the association between the four diet-quality index (DQI) scores, the Alternative Health Eating Index-2010 (AHEI-2010), Alternate Mediterranean Diet (aMED); Dietary Approaches to Stop Hypertension (DASH) and Heathy Diet Indicator (HDI) with liver cancer risk, using data from the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese men and women aged 45-74 at enrollment in 1993-1998 with up to 25 years of follow-up.

Methods. The Cox proportional hazard regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of HCC with each DQI after adjustment for multiple potential confounders. The unconditional logistic regression method was used to evaluate the associations between the DQIs and HCC risk among a subset of individuals who tested negative for hepatitis B surface antigen (HBsAg).

Results. During an average 17.7 years of follow-up, 561 incident HCC cases were identified. High scores of AHEI-2010, aMED and DASH, representing higher dietary quality, were associated with lower risk of HCC (all Ptrend&lt;0.05). Compared with the lowest quartile, HRs (95% CIs) of HCC risk for the highest quartile of AHEI-2010, aMED and DASH were 0.71 (0.55-0.91), 0.73 (0.54-0.98), and 0.68 (0.52-0.89), respectively. These inverse associations were stronger in men than in women. No significant association between HDI and HCC risk was observed. Among HBsAg-negative individuals, similar inverse associations were observed, and the strongest inverse association was for aMED that reached statistically significance level (HRQ4vsQ1=0.48, 95% CI: 0.24-0.98).

Conclusion. Higher scores of AHED, aMED, and DASH were significantly associated with reduced risk of HCC in this Asian population. The findings support the notion that adherence to a healthier diet may lower the risk of HCC, suggesting that dietary modification may be an effective approach for primary prevention of HCC.

Funding: The Singapore Chinese Health Study was supported by the National Institutes of Health (NIH) of the United States (grants # R01 CA144034 and UM1 CA182876).

Citation Format: Hung N. Luu, Nithya Neelakantan, Ting-ting Geng, Renwei Wang, Jennifer Adams-Haduch, Aizhen Jin, Rob M. Van Dam, Woon-Puay Koh, Jian-Min Yuan. Diet quality indexes and risk of hepatocellular carcinoma: Findings from the Singapore Chinese Health Study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4647.

Abstract 4641: Association between dietary tomato intake and the risk of hepatocellular carcinoma: Findings from a prospective cohort study

Background: Intake of tomato and/or lycopene have been found to be associated with reduced risk of several cancer types, but epidemiological data on risk of hepatocellular carcinoma (HCC) are sparse.

Methods: The associations of tomato and lycopene consumption with risk of HCC were examined in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese men and women aged 45-74 years at enrollment in 1993-1998 with 25 years of follow-up. Tomato and lycopene consumption was evaluated using a validated semi-quantitative food frequency questionnaire. Incident HCC cases were ascertained through the linkage analysis with the nationwide Singapore cancer registry. Cox proportional hazard regression was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of HCC with the consumption of tomato and lycopene among all cohort participants, and unconditional logistic regression was used to assess the association among individuals negative for hepatitis B surface antigen (HBsAg).

Results: After a mean follow-up of 17.6 years, 561 incident HCC cases were identified. Higher tomato intake was associated with lower risk of HCC after adjustment for multiple potential confounders (Ptrend&lt;0.001). Compared to the lowest quartile, HRs (95% CIs) of HCC for the 2nd, 3rd, and 4th quartile of tomato intake were 0.70 (0.56-0.88), 0.73 (0.58-0.92), and 0.63 (0.49-0.81). Among HBsAg-negative individuals, the inverse association remained (Ptrend=0.03). There was no association between lycopene intake and HCC risk (Ptrend=0.54).

Conclusion: Tomato intake may offer protection against the development of HCC, particularly among individuals without chronic infection with hepatitis B virus.

Citation Format: Claire E. Thomas, Hung N. Luu, Renwei Wang, Jennifer Adams-Haduch, Jian-Min Yuan, Aizhen Jin, Woon-Puay Koh. Association between dietary tomato intake and the risk of hepatocellular carcinoma: Findings from a prospective cohort study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4641.

Abstract 2344: 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) were examined substantially, their combined impact on HCC risk has not been evaluated.

Methods. The association of a composite score of healthy lifestyle factors, including body mass index, alcohol consumption, cigarette smoking, alternative Mediterranean Diet (aMED), and sleep duration, with the risk of developing HCC was examined in the Singapore Chinese Health Study (SCHS), an on-going prospective cohort of 63,257 Chinese men and women aged 45-74 at enrollment in 1993-1998 with up to 25 years of follow-up. Cox proportional hazard regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of HCC with the composite score after adjustment for multiple potential confounders. The unconditional logistic regression method was used to confirm the association between the composite lifestyle score and HCC risk among hepatitis B surface antigen (HBsAg) negative individuals to eliminate its potential confounding effect.

Results. After a mean follow-up of 17.7 years, 561 participants of the SCHS developed HCC. Individuals with higher composite scores, which represented for healthier lifestyles, were at significantly lower risk of HCC. Compared with the lowest composite score (i.e., 0-4), the HRs (95% CIs) for 5, 6, 7 and 8 were 0.48 (0.36-0.64), 0.44 (0.34-0.67), 0.37 (0.28-0.48), and 0.26 (0.17-0.39), respectively (Ptrend&lt;0.001). A similar inverse association was observed in participants with negative HBsAg serology; HR was 0.12 (95% CI: 0.04-0.38) for the highest versus the lowest category of the composite scores (Ptrend=0.01).

Conclusion. Healthy lifestyles are protective against the development of HCC, especially for individuals without viral infection. This finding highlights the importance of a comprehensive lifestyle modification strategy for primary prevention of HCC.

Funding: The Singapore Chinese Health Study was supported by the National Institutes of Health (NIH) of the United States (grants # R01 CA144034 and UM1 CA182876).

Citation Format: Hung N. Luu, Renwei Wang, Jaideep Behari, Jennifer Adams-Haduch, Andrew O. Odegaard, George Goh Bee, Aizhen Jin, Woon-Puay Koh, Jian-Min Yuan. Composite score of healthy lifestyle factors and risk of hepatocellular carcinoma: Findings from a prospective cohort study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2344.

Fabrication of a Self-Curling Cuff with a Soft, Ionically Conducting Neural Interface

Direct current (DC) has the potential not only to excite but also to inhibit neurons. This property of DC stimulus has been used for generating peripheral nerve blocks. One translational challenge of DC-based neuromodulation technologies, especially for pain suppression, is that the commercially available cuff electrodes have metal-tissue interfaces that are incapable of delivering DC safely. Passing DC through any metal-tissue interface generates harmful electrochemical products which can damage the target nerve. To address this issue, we present a fabrication process for making self-curling silicone cuffs with paper/agar based, ionically conducting neural interface. We fabricate monopolar as well as bipolar cuffs and demonstrate that the electrode impedances can be easily controlled by modulating the paper/agar channel dimensions. Further, we perform in-vivo implantation of these electrodes on a rat sciatic nerve to qualitatively validate the self-curling action.

Association between Dietary Tomato Intake and the Risk of Hepatocellular Carcinoma: The Singapore Chinese Health Study

BACKGROUND

Intake of tomato and/or lycopene has been associated with reduced risk of several cancers, but there is no report on the association with risk of hepatocellular carcinoma (HCC).

METHODS

The associations of tomato and lycopene consumption with risk of HCC were examined in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese ages 45 to 74 years at enrollment. Diet was assessed using a validated semiquantitative food frequency questionnaire. Cox proportional hazard regression models were used to estimate HR and its 95% confidence interval (CI) of HCC with the consumption of tomato and lycopene among all cohort participants, and unconditional logistic regression was used to assess the association by hepatitis B surface antigen (HBsAg) positivity in a nested case-control study.

RESULTS

After a mean follow-up of 17.6 years, 561 incident HCC cases were identified. Higher tomato intake was associated with lower risk of HCC after adjustment for potential confounders (P _trend < 0.001). Compared with the lowest quartile, HRs (95% CIs) of HCC for the second, third, and fourth quartile of tomato intake were 0.70 (0.56-0.88), 0.73 (0.58-0.92), and 0.63 (0.49-0.81). Among HBsAg-negative individuals, the inverse association remained (P _trend = 0.03). There was no association between lycopene intake and HCC risk (P _trend = 0.54).

CONCLUSIONS

Tomato intake may offer protection against the development of HCC, particularly among individuals without chronic infection with hepatitis B virus.

IMPACT

Tomato intake is a low-cost preventative measure against HCC that may help reduce risk due to increasing rates of nonalcoholic fatty liver disease.

Dietary Intakes of Trace Elements and the Risk of Kidney Cancer: The Singapore Chinese Health Study

Background: Epidemiological studies have demonstrated separately that patients with kidney stone may have higher dietary intake of zinc and higher risk of developing kidney cancer. We prospectively assessed the associations of dietary zinc and other trace elements with kidney cancer risk for the first time.Methods: We used data from the prospective Singapore Chinese Health Study that recruited 63,257 adult Chinese residing in Singapore between 1993 and 1998. A validated food frequency questionnaire and the Singapore Food Composition Database was used to compute the values of intake for zinc, copper and manganese. We identified incident cancer cases via linkage with nationwide cancer registry, and used Cox proportional hazard models to compute hazard ratio (HR) and 95% confidence interval (CI) for the association with kidney cancer risk.Results: There were 229 incident kidney cancer cases after median follow-up of 20.1 years. Dietary zinc intake was positively associated with higher kidney cancer risk; the HR comparing the extreme quartiles of zinc intake was 1.74 (95% CI: 1.02-2.97; P-trend = 0.033). Conversely, intakes of copper and manganese were not associated with kidney cancer risk.Conclusions: The positive association between dietary zinc and risk of kidney cancer suggests that zinc may be implicated in renal carcinogenesis.

Association between leukocyte telomere length and the risk of pancreatic cancer: Findings from a prospective study

INTRODUCTION

Telomeres and telomerase play important role in maintaining chromosome integrity and genomic stability. Recent epidemiologic data showed inconsistent findings which suggested that both short and long leukocyte telomeres could be associated with increased risk of pancreatic cancer. We prospectively examined the association between telomere length and pancreatic cancer risk in a population-based cohort study.

METHODS

The Singapore Chinese Health Study recruited 63,257 Chinese aged 45 to 74 years from 1993 to 1998 in Singapore. Relative telomere length in peripheral blood leukocytes was quantified using a validated monochrome multiplex quantitative polymerase chain reaction method in 26,540 participants, including 116 participants who later developed pancreatic cancer after an average of 13 years of follow-up. Cox proportional hazard regression method was used to calculate hazard ratio (HR) and its 95% confidence interval (CI) of pancreatic cancer risk associated with telomere length, with adjustment for confounding factors.

RESULTS

Longer telomeres were significantly associated with higher risk of pancreatic cancer (Ptrend = 0.02). Compared with lowest quartile, subjects with highest quartile of telomere length had an HR of 2.18 (95% CI: 1.25-3.80) for developing pancreatic cancer. In stratified analysis, this association remained among pancreatic adenocarcinoma patients but not among pancreatic non-adenocarcinoma patients. In continuous scale, the HRs and 95% CIs were 3.08 (1.17-8.11) for adenocarcinoma patients and 1.47 (0.43-5.06) for non-adenocarcinoma patients. The HRs and 95% CIs of the highest quartile of telomere length, compared with the lowest quartile, for adenocarcinoma and non-adenocarcinoma were 2.50 (1.22-5.13) and 1.63 (0.66-4.03), respectively. The length of follow-up from the collection of blood for the measurement of telomere length to the diagnosis of cancer (median = 8.0, range: from 5.0 months to 16.2 years) had no significant impact on the association between telomere length and pancreatic cancer risk.

CONCLUSIONS

The present study demonstrates that longer telomeres are associated with increased risk of overall pancreatic cancer.

Abstract 3133: Leukocyte telomere length, cancer incidence and all-cause mortality among Chinese adults: Singapore Chinese health study

Background: Telomeres play a key role in the chromosomal maintenance and stability. To date, very few studies have investigated the association between leukocyte telomere length with cancer incidence and all-cause mortality, particularly among Asian population.

Methods: 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 incident cancer and deaths by quintiles of telomere length were calculated using the Cox proportional hazards regression method with adjustment for potential confounders.

Results: During 13.2 years of follow-up, 4,353 individuals developed cancer and 2,660 participants died of cancer. Participants with the longest telomeres had significantly 16% higher risk of developing cancer compared to those with the shortest telomeres after controlling for established risk factors (95% CI: 1.06, 1.28; Ptrend= 0.0003). We found similar pattern of results for lung adenocarcinoma (HRQ5 vs. Q1=2.89; 95% CI: 1.95, 4.27), pancreatic cancer (HRQ5 vs. Q1=2.36; 95% CI: 1.29, 4.32), kidney cancer (HRQ5 vs. Q1=3.23; 95% CI: 1.47, 7.53), and genitourinary system cancers including kidney, renal pelvis, ureter, and bladder (HRQ5 vs. Q1=1.56; 95% CI: 1.02, 2.39). In contrast, longer telomeres were associated with lower risk of overall death (HRQ5 vs. Q1=0.93; 95% CI: 0.86, 1.00), and deaths due to ischemic heart disease (HRQ5 vs. Q1=0.85; 95% CI: 0.70, 1.02), respiratory disease (HRQ5 vs. Q1=0.76; 95% CI: 0.64, 0.91), non-cancer (HRQ5 vs. Q1=0.80; 95%: 0.73, 0.88) and other diseases (HRQ5 vs. Q1=0.77; 95% CI: 0.63, 0.94).

Conclusion: The findings of this cohort study support the hypothesis that longer telomere length may be a risk factor for cancer and cancer-related deaths, but might have opposing impact on overall survival.

Funding Sources: National Institutes of Health (NIH) (R01 CA144034 and UM1 CA182876); NIH/NCI T32CA186873; National Medical Research Council, Singapore (NMRC/CSA/0055/2013); NIH (P20CA210300).

Citation Format: Hamed Samavat, Hung N. Luu, Renwei Wang, Aizhen Jin, Woon-Puay Koh, Jian-Min Yuan. Leukocyte telomere length, cancer incidence and all-cause mortality among Chinese adults: Singapore Chinese health study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3133.

Soy and tea intake on cervical cancer risk: the Singapore Chinese Health Study

PURPOSE

Soy isoflavones and tea catechins have immunomodulating and chemopreventive properties relevant for cervical carcinogenesis; however, there are limited epidemiologic data on the relationship of soy and tea consumption with cervical cancer risk. The aim of our study was to examine effects of soy and tea intake on cervical cancer risk among Singapore Chinese women.

METHODS

The association between intake of soy and tea drinking and cervical cancer risk was investigated in a prospective, population-based cohort of 30,744 Chinese women in Singapore with an average 16.7 years of follow-up and 312 incident cervical cancer cases. Multivariable proportional hazard models were used to estimate hazard ratio (HR) and 95% confidence interval (CI) of cervical cancer associated with intake levels of soy and tea.

RESULTS

High intake of soy alone was associated with a statistically borderline significant 20% reduced risk of cervical cancer (HR 0.80, 95% CI 0.61, 1.05) while green tea alone was not (HR 0.97, 95% CI: 0.76, 1.22). In stratified analysis, high intake of soy was associated with a statistically significant decrease in cervical cancer risk among green tea drinkers (HR 0.43; 95% CI 0.28, 0.69) but not among non-drinkers of green tea. The difference in the soy-cervical cancer risk association between green tea drinkers and non-drinkers was statistically significant (p for interaction = 0.004). This inverse association between soy intake and cervical cancer risk remained after further adjustment for human papillomavirus serostatus. Black tea consumption was not associated with cervical cancer risk.

CONCLUSIONS

These findings suggest that a protective effect of soy against cervical cancer development may depend on green tea constituents.

Association between prediagnostic leukocyte telomere length and breast cancer risk: the Singapore Chinese Health Study

BACKGROUND

Telomeres and telomerase play key roles in the chromosomal maintenance and stability. Recent epidemiological studies have shown that longer telomeres are associated with increased risk of several cancer types. However, epidemiological data for telomere length and risk of breast cancer are sparse.

METHODS

We prospectively studied the association between telomere length and risk of breast cancer in 14,305 middle-aged or older Chinese women of the Singapore Chinese Health Study including 442 incident breast cancer cases after 12.3 years of follow-up. Relative telomere length in peripheral blood leukocytes was quantified using a validated monochrome multiple quantitative polymerase chain reaction method. The Cox proportional hazard regression method was used to estimate hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for breast cancer associated with longer telomeres after adjustment for potential confounders.

RESULTS

Longer telomeres were significantly associated with higher risk of breast cancer in a dose-dependent manner (P_trend = 0.006); the highest quartile of telomere length was associated with a statistically significant 47% higher risk of breast cancer compared with the lowest quartile of telomere length after the adjustment for age and other known risk factors for breast cancer (HR_{Q4 vs Q1} = 1.47, 95% CI = 1.11, 1.94).

CONCLUSIONS

The findings of the present study support the hypothesis that longer telomeres may be a risk factor for breast cancer. Telomere length in peripheral blood leukocytes may be developed as a biomarker for breast cancer risk prediction.

Clot Burden Score and Early Ischemia Predict Intracranial Hemorrhage following Endovascular Therapy

BACKGROUND AND PURPOSE

Intracranial hemorrhage is a known complication following endovascular thrombectomy. The radiologic characteristics of a CT scan may assist with hemorrhage risk stratification. We assessed the radiologic predictors of intracranial hemorrhage following endovascular therapy using data from the INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography) study.

MATERIALS AND METHODS

Patients undergoing endovascular therapy underwent baseline imaging, postprocedural angiography, and 24-hour follow-up imaging. The primary outcome was any intracranial hemorrhage observed on follow-up imaging. The secondary outcome was symptomatic hemorrhage. We assessed the relationship between hemorrhage occurrence and baseline patient characteristics, clinical course, and imaging factors: baseline ASPECTS, thrombus location, residual flow grade, collateralization, and clot burden score. Multivariable logistic regression with backward selection was used to adjust for relevant covariates.

RESULTS

Of the 199 enrolled patients who met the inclusion criteria, 46 (23%) had an intracranial hemorrhage at 24 hours. On multivariable analysis, postprocedural hemorrhage was associated with pretreatment ASPECTS (OR, 1.56 per point lost; 95% CI, 1.12-2.15), clot burden score (OR, 1.19 per point lost; 95% CI, 1.03-1.38), and ICA thrombus location (OR, 3.10; 95% CI, 1.07-8.91). In post hoc analysis, clot burden scores of ≤3 (sensitivity, 41%; specificity, 82%; OR, 3.12; 95% CI, 1.36-7.15) and pretreatment ASPECTS ≤ 7 (sensitivity, 48%; specificity, 82%; OR, 3.17; 95% CI, 1.35-7.45) robustly predicted hemorrhage. Residual flow grade and collateralization were not associated with hemorrhage occurrence. Symptomatic hemorrhage was observed in 4 patients.

CONCLUSIONS

Radiologic factors, early ischemia on CT, and increased CTA clot burden are associated with an increased risk of intracranial hemorrhage in patients undergoing endovascular therapy.

Coffee, tea, caffeine, and risk of nonmelanoma skin cancer in a Chinese population: The Singapore Chinese Health Study

BACKGROUND

Although epidemiologic studies in populations of European descent suggest a possible chemoprotective effect of caffeine against nonmelanoma skin cancer (NMSC), data in Asian populations are lacking.

OBJECTIVES

We examined the relationship of coffee, tea, and caffeine consumption with NMSC risk among Chinese in Singapore.

METHODS

We used data from the Singapore Chinese Health Study, a prospective cohort of 63,257 men and women who were 45 to 74 years old at recruitment from 1993 to 1998. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by using multivariable Cox proportional hazard models.

RESULTS

Coffee drinking was associated with reduced NMSC risk in a dose-dependent manner (P trend < .0001). Compared with those who drank coffee less than weekly, those who drank 3 or more cups per day had a lower risk of basal cell carcinoma (HR, 0.54; 95% CI, 0.31-0.93) and a lower risk of squamous cell carcinoma (HR, 0.33; 95% CI, 0.13-0.84). Compared with nondrinkers of black tea, daily drinkers of black tea also had a reduced risk of NMSC (HR, 0.70; 95% CI, 0.52-0.94). Caffeine intake reduced NMSC risk in a stepwise manner (P trend = .0025); subjects with a caffeine intake of 400 mg/d or more had the lowest risk (HR, 0.59; 95% CI, 0.34-1.04).

CONCLUSION

Consumption of caffeinated drinks such as coffee and black tea may reduce the risk of NMSC among Chinese.

Consumption of Coffee but Not of Other Caffeine-Containing Beverages Reduces the Risk of End-Stage Renal Disease in the Singapore Chinese Health Study

Background

Cross-sectional studies suggest that coffee drinking is associated with better renal function. However, to our knowledge, no prospective study has examined its relation with the risk of end-stage renal disease (ESRD).

Objective

We examined the relations between coffee, tea, soda, and total caffeine consumption and the risk of ESRD among middle-aged and older Chinese in Singapore.

Methods

We used data from the Singapore Chinese Health Study, a prospective cohort of 63,257 men and women aged 45-74 y at recruitment from 1993 to 1998. Baseline information on the consumption of caffeinated coffee and other caffeinated beverages (tea and sodas), habitual diet, medical history, and lifestyle factors was obtained via in-person interviews. The standard serving size of 1 cup was assigned as 237 mL in the questionnaire. Incident ESRD cases were identified via linkage with the nationwide registry. We used multivariable Cox regression models to estimate HRs and 95% CIs of ESRD risk associated with the consumption of caffeinated beverages, with adjustment for potential confounders.

Results

After a mean follow-up of 16.8 y, 1143 cohort subjects developed ESRD. Compared with those who drank coffee less than daily, the HR (95% CI) was 0.91 (0.79, 1.05) for those who drank 1 cup of coffee/d and 0.82 (0.71, 0.96) for those who drank ≥2 cups/d (P-trend = 0.012). When stratified by sex, this association was observed in men but not in women. Compared with those who drank less than daily, the HR (95% CI) for drinking ≥2 cups/d was 0.71 (0.57, 0.87) among men and 0.97 (0.78, 1.19) among women (P-interaction = 0.03). Conversely, intakes of tea, soda, or total caffeine were not associated with the risk of ESRD in multivariable models.

Conclusion

The consumption of ≥2 cups of coffee/d may reduce the risk of ESRD in the general population, especially among men. This study was registered at http://www.clinicaltrials.gov as NCT03356340.

Occupational exposure to endocrine disrupting substances and the risk of breast Cancer: the Singapore Chinese health study

Background

Evidence from basic research links exposure to endocrine disrupting chemicals (EDCs) with a higher risk for breast cancer. However, there is less evidence from observational epidemiological research and the results are equivocal. Therefore, we examined the association between occupational exposure to substances where exposure to EDCs is likely and the risk of breast cancer.

Methods

A prospective study consisting of a population-based cohort of 33,458 Singaporean Chinese women aged 45–74 years enrolled in the Singapore Chinese Health Study (SCHS) from 1993 to 98 and followed through 2014. Subjects’ self-reported occupational exposure and duration to industries, job titles, and substance types were garnered at baseline, and cases of incident breast cancer (N = 988) were determined by linkage with the Singapore Cancer Registry. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated for exposure to substances, job titles, and industries.

Results

There was no association between cumulative exposure to substances via occupation where EDC exposure is likely and risk of breast cancer. These results were consistent for hypothesized high (HR 0.94, 95% CI: 0.66–1.35), medium (HR 1.03 95% CI: 0.77–1.38) and low (HR 0.74, 95% CI 0.48–1.13) combined substance exposure groups when compared with those who were not exposed via occupation. Similar null associations were observed when examining job titles and industry categories.

Conclusions

There was no association between EDC related occupational exposures and breast cancer risk in working women of the Singaporean Chinese Health Study. Future studies that employ rigorous methods with regard to exposure assessment of EDCs are needed.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5862-2) contains supplementary material, which is available to authorized users.

Coffee and tea drinking in relation to risk of hip fracture in the Singapore Chinese Health Study

Meta-analyses of studies conducted among Western populations suggest that coffee consumption does not affect osteoporotic fracture risk. However, experimental studies have shown that the effect of caffeine on bone health may depend on dosage. We examined the associations between consumption of coffee, tea and caffeine and risk of hip fracture in an Asian cohort. In a population-based prospective cohort of 63,257 Chinese men and women aged 45-74 years in Singapore, a validated semi-quantitative food frequency questionnaire was used to assess habitual consumption of coffee and tea at baseline. Cox proportional hazards regression models were used to estimate hazard ratio (HR) and 95% confidence interval (CI) for risk of hip fracture with adjustment for potential confounders. During a mean follow-up of 16.7 years, 2502 incident hip fracture cases were identified. Compared to coffee drinkers <1 cup/week, those who drank ≥4 cups/day had a statistically significant higher risk to develop hip fractures, the HR (95% CI) was 1.32 (1.07, 1.63) in the whole cohort analysis, 1.46 (1.01, 2.10) for men and 1.33 (1.02, 1.72) for women. Among postmenopausal women, compared to those who drank coffee <1 cup/week, drinking 2-3 cups/day was associated with the lowest risk [HR: 0.88 (0.76, 1.01)] and drinking ≥4 cups/day was associated with the highest risk [HR: 1.31 (1.00, 1.71)]. Similar associations with caffeine intake were found among postmenopausal women. Restricted spline analyses suggested a non-linear association between coffee/caffeine consumption and hip fracture risk in postmenopausal women (p for non-linearity ≤ 0.05). No association was found with tea consumption in either sex. These data suggest that drinking coffee ≥4 cups/day is associated with a higher hip fracture risk, while a moderate intake may alleviate risk in postmenopausal women. Future studies should corroborate these results to determine levels of optimal coffee consumption in relation to bone health.

Telomere length and risk of developing gastric adenocarcinoma: The Singapore Chinese Health Study

BACKGROUND

Extreme telomere length has been previously reported to be associated with increased risk of gastric cancer. However, evidence from prospective studies on a relative large sample size with long-term follow-up to further corroborate previous study findings is meager.

METHODS

The association between peripheral blood leukocyte telomere length and risk of gastric adenocarcinoma was prospectively examined in a cohort of 26,540 middle-aged or older Chinese nested in the Singapore Chinese Health Study. Telomere length was determined using a validated qPCR-based method. The Cox proportional regression method was used to estimate hazard ratio (HR) and its 95% confidence interval (CI) of gastric adenocarcinoma associated with telomere length after adjustment for potential confounders. Restricted cubic spline analysis was applied to assess the nonlinear relationship between telomere length and gastric cancer risk.

RESULTS

A U-shaped association was found between telomere length and risk of gastric adenocarcinoma (P _nonlinearity = 0.020). Compared with the second quintile of telomere length, a statistically significant higher risk of gastric adenocarcinoma was associated with either the lowest quintile (HR = 1.63, 95% CI, 1.07-2.47) or the highest quintile (HR = 1.55, 95% CI, 0.97-2.47) of telomere length. This U-shaped relationship was more apparent in men and younger individuals.

CONCLUSIONS

This is the first prospective study demonstrating a higher risk of gastric cancer to be associated with either extremely short or extremely long telomere length. Short and long telomere length may function differently in the early and late stages of gastric carcinogenesis.

Leukocyte telomere length in relation to risk of lung adenocarcinoma incidence: Findings from the Singapore Chinese Health Study

Telomeres are crucial in the maintenance of chromosome integrity and genomic stability. Critically short telomeres can trigger programed cell death while cells with longer telomeres may have increased likelihood of replicative errors, resulting in genetic mutations and chromosomal alterations, and ultimately promoting oncogenesis. Data on telomere length and lung cancer risk from large prospective cohort studies are spare. Relative telomere length in peripheral blood leukocytes was quantified using a validated monochrome multiplex quantitative polymerase chain reaction (qPCR) method in 26,540 participants of the Singapore Chinese Health Study. After a follow-up of 12 years, 654 participants developed lung cancer including 288 adenocarcinoma, 113 squamous cell carcinoma and 253 other/unknown histological type. The Cox proportional hazard regression was used to estimate hazard ratio (HR) and 95% confidence interval (CI). HR of lung adenocarcinoma for individuals in the highest comparing the lowest 20 percentile of telomere length was 2.84 (95% CI 1.94-4.14, p_trend  < 0.0001). This positive association was present in never smokers (p_trend  < 0.0001), ever smokers (p_trend  = 0.0010), men (p_trend  = 0.0003), women (p_trend  < 0.0001), and in shorter (p_trend  = 0.0002) and longer (p_trend  = 0.0001) duration of follow-up. There was no association between telomere length and risk of squamous cell carcinoma or other histological type of lung cancer in all or subgroups of individuals. The agreement of results from this prospective cohort study with those of previous prospective studies and Mendelian randomization studies suggest a possible etiological role of telomere length in the development of lung adenocarcinoma.