Association of Cantonese dietary patterns with mortality risk in older Chinese: a 16-year follow-up of a Guangzhou Biobank cohort study.

Background: Evidence about the associations between Cantonese dietary patterns and mortality is scarce. We examined the prospective association of the dietary pattern with all-cause, cancer and cardiovascular disease (CVD) mortality in older Chinese. Methods: We included 19 598 participants of a Guangzhou Biobank cohort study aged 50+ years, who were recruited from 2003 to 2006 and followed up until July, 2022. The diet was assessed by using a 300-item validated food frequency questionnaire. The food items were collapsed into 27 food groups. Factor analysis (FA) was used to identify dietary patterns. Multivariable Cox regression produced hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. Results: During 305 410 person-years, 4966 deaths including 1971 CVD, 1565 cancer and 1436 other-causes occurred. Four dietary patterns were identified by FA. No association of the vegetable-based dietary pattern with all-cause, CVD and cancer mortality was found. Compared with the lowest quartile of the healthy Cantonese dietary pattern score, the highest quartile showed lower risks of all-cause (HR 0.86, 95% CI 0.80-0.94) and CVD mortality (HR 0.84, 95% CI 0.72-0.97). The highest quartile of the nut and fruit dietary pattern showed lower risks of all-cause (HR 0.92, 95% CI 0.85-0.99) and CVD mortality (HR 0.82, 95% CI 0.72-0.93), while the unhealthy western dietary pattern was associated with a higher risk of all-cause (HR 1.10, 95% CI 1.01-1.19) and cerebrovascular disease mortality (HR 1.28, 95% CI 1.03-1.58). Conclusion: We have first identified four dietary patterns based on the Cantonese cuisine and found that healthy Cantonese and nut and fruit dietary patterns were associated with lower risks of all-cause and CVD mortality, whereas the unhealthy western dietary pattern was associated with a higher risk of all-cause and cerebrovascular disease mortality.

Associations of soy product intake with all-cause, cardiovascular disease and cancer mortality: Guangzhou Biobank Cohort Study and updated meta-analyses.

PURPOSE: We examined the associations of soy product intake with all-cause, cardiovascular disease (CVD), and cancer mortality and mediations through CVD risk factors based on the Guangzhou Biobank Cohort Study (GBCS), and conducted updated meta-analyses. METHODS: A total of 29,825 participants aged 50 + years were included. Causes of death were identified through record linkage. Soy product intake was assessed by food frequency questionnaire. Cox proportional hazards regression was used to analyze the associations between soy product intake and mortality, yielding hazard ratios (HRs) and 95% confidence intervals (CIs). Mediation analyses with CVD risk factors as mediators, and updated meta-analyses were conducted. RESULTS: During 454,689 person-years of follow-up, 6899 deaths occurred, including 2694 CVD and 2236 cancer. Participants who consumed soy product of 1-6 portions/week, versus no consumption, had significantly lower risks of all-cause and CVD mortality (adjusted HR (95% CI) 0.91 (0.86, 0.97) and 0.87 (0.79, 0.96), respectively). In participants who consumed soy product of ≥ 7 portions/week, the association of higher intake with lower CVD mortality was modestly mediated by total cholesterol (4.2%, 95% CI 1.0-16.6%). Updated meta-analyses showed that the highest level of soy product intake, versus the lowest, was associated with lower risks of all-cause and CVD mortality (pooled HR (95% CI) 0.92 (0.88, 0.96) and 0.92 (0.87, 0.98), respectively). CONCLUSION: Moderate and high soy product intake were associated with lower risks of all-cause and CVD mortality. Our findings provide support for current dietary guidelines recommending moderate soy product intake, and contribute additional evidence regarding the potential protective effects of high soy product intake.

Association of Measures of Glucose Metabolism with Colorectal Cancer Risk in Older Chinese: A 13-Year Follow-up of the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy and Meta-Analysis.

BACKGRUOUND: Abnormal glucose metabolism is a risk factor for colorectal cancer (CRC). However, association of glycosylated hemoglobin (HbA1c) with CRC risk remains under-reported. We examined the association between glycemic indicators (HbA1c, fasting plasma glucose, fasting insulin, 2-hour glucose, 2-hour insulin, and homeostasis model of risk assessment-insulin resistance index) and CRC risk using prospective analysis and meta-analysis. METHODS: Participants (n=1,915) from the Guangzhou Biobank Cohort Study-Cardiovascular Disease Substudy were included. CRC events were identified through record linkage. Cox regression was used to assess the associations of glycemic indicators with CRC risk. A meta-analysis was performed to investigate the association between HbA1c and CRC risk. RESULTS: During an average of 12.9 years follow-up (standard deviation, 2.8), 42 incident CRC cases occurred. After adjusting for potential confounders, the hazard ratio (95% confidence interval [CI]) of CRC for per % increment in HbA1c was 1.28 (95% CI, 1.01 to 1.63) in overall population, 1.51 (95% CI, 1.13 to 2.02) in women and 1.06 (95% CI, 0.68 to 1.68) in men. No significant association of other measures of glycemic indicators and baseline diabetes with CRC risk was found. Meta-analyses of 523,857 participants including our results showed that per % increment of HbA1c was associated with 13% higher risk of CRC, with the pooled risk ratio being 1.13 (95% CI, 1.01 to 1.27). Subgroupanalyses found stronger associations in women, colon cancer, Asians, and case-control studies. CONCLUSION: Higher HbA1c was a significant predictor of CRC in the general population. Our findings shed light on the pathology of glucose metabolism and CRC, which warrants more in-depth investigation.

Association of fish and meat consumption with non-alcoholic fatty liver disease: Guangzhou Biobank Cohort Study.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Unhealthy dietary habit is one of major risk factors of NAFLD. However, the associations between specific types of fish and meat consumption and NAFLD remain inconclusive. We explored the associations of fish and meat consumption with NAFLD risk in middle-aged and older Chinese. METHODS: We collected information on 1,862 participants aged 50 years or older from Guangzhou Biobank Cohort Study in 2009 to 2010. Fish and meat consumption was assessed using a validated food-frequency questionnaire. NAFLD was diagnosed by ultrasound. Multivariable logistic regression was used to examine the associations of fish and meat consumption with the presence of NAFLD. RESULTS: The average age was 61.0 (standard deviation = 6.5) years for the participants, 50.2% were women, and 37.2% were diagnosed with NAFLD. After adjusting for age, sex, education, family income, occupation, smoking status, drinking status, physical activity and several metabolic traits, compared with 0 serving/week (one serving = 50 g), fatty fish consumption of ≥ 3 servings/week showed higher odds of NAFLD (odds ratio (OR) and 95% confidence interval (CI): 1.64 (1.12, 2.39)). The highest (≥ 11 servings/week of red meat and poultry; ≥ 3 servings/week of processed meat) versus the lowest (0-3 servings/week of red meat and poultry; 0 serving/week of processed meat) consumption of all other types of meats, including red meat, poultry and processed meat, showed no association with NAFLD (1.17 (0.75, 1.81), 1.02 (0.42, 2.50) and 0.85 (0.50, 1.45), respectively). Aquatic and sea food, and red meat had negative indirect effects on NAFLD via systolic blood pressure and/or high-density lipoprotein cholesterol. Processed meat had positive indirect effects on NAFLD via body mass index, waist circumference, fasting plasma glucose and triglycerides. CONCLUSION: High consumption of fatty fish was associated with higher NAFLD risk. Our results, if causal, provide evidence that limiting consumption of fatty fish can be considered as part of NAFLD lifestyle prevention and treatment.

Associations of meat, fish and seafood consumption with kidney function in middle-aged to older Chinese: a cross-sectional study based on the Guangzhou Biobank Cohort Study.

OBJECTIVE: To examine the associations of red meat, poultry, fish and seafood and processed meat consumption with kidney function in middle-aged to older Chinese. DESIGN: A cross-sectional study based on the Guangzhou Biobank Cohort Study. SETTING: Community-based sample. PARTICIPANTS: 9768 participants (2743 men and 7025 women) aged 50+ years. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was estimated glomerular filtration rate (eGFR) derived from the Chinese-specific equation based on the Modification of Diet in Renal Disease (MDRD) equation (c-aGFR). eGFR derived from the original isotope-dilution mass spectrometry-traceable MDRD study equation, and prevalent chronic kidney disease (CKD) defined as c-aGFR<60 mL/min/1.73 m2 were considered the secondary outcomes. RESULTS: After adjusting for sex, age, body mass index, education, occupation, family income, smoking status, alcohol use, physical activity, daily energy intake, self-rated health and chronic disease history (diabetes, hypertension and dyslipidaemia), compared with processed meat consumption of 0-1 portion/week, those who consumed ≥3 portions/week had lower c-aGFR (ß=-2.74 mL/min/1.73 m2, 95% CI=-4.28 to -1.20) and higher risk of prevalent CKD (OR=1.40, 95% CI=1.09 to 1.80, p<0.0125). Regarding fish and seafood consumption, the associations varied by diabetes (p for interaction=0.02). Fish and seafood consumption of ≥11 portions/week, versus 0-3 portions/week, was non-significantly associated with higher c-aGFR (ß=3.62 mL/min/1.73 m2, 95% CI=-0.06 to 7.30) in participants with diabetes, but was associated with lower c-aGFR in normoglycaemic participants (ß=-1.51 mL/min/1.73 m2, 95% CI=-2.81 to -0.20). No significant associations of red meat or poultry consumption with c-aGFR nor prevalent CKD were found. Similar results were found for meat, fish and seafood consumption with eGFR. CONCLUSIONS: Higher processed meat, fish and seafood consumption was associated with lower kidney function in normoglycaemic participants. However, the associations in participants with diabetes warrant further investigation.

Quantity and Variety in Fruit and Vegetable Consumption and Mortality in Older Chinese: A 15-year Follow-Up of a Prospective Cohort Study.

BACKGROUND: Independent associations of quantity and variety of fruit and vegetables (FVs) with mortality in older people are still unclear. OBJECTIVES: This study aimed to explore the association between the quantity and variety in FV consumption and mortality in older Chinese. METHODS: A total of 19,597 participants of the Guangzhou Biobank Cohort Study aged >50 y were recruited from 2003 to 2006 and followed up until April 2021. The diet was assessed using a 300-item validated FFQ. Variety as a continuous variable was defined as the number of unique FV items (excluding potatoes, legumes, and fruit juices) intake per week over the past week. The associations of quantity and variety of FVs with mortality were analyzed, and analyses by the color of edible parts was performed. Multivariable Cox regression yielded HRs and 95% CIs. RESULTS: During 286,821 person-year of follow-up, 4385 deaths occurred, including 1678 cardiovascular diseases (CVD), 1450 cancer, and 1257 other causes. Compared with the lowest quintile of variety in FV, the highest quintile was associated with lower risks of all-cause (HR: 0.81; 95% CI: 0.73-0.89) and CVD mortality (HR: 0.79; 95% CI 0.67-0.92). A greater variety of green and white FV intake was associated with lower risks of all-cause and CVD morality, and a greater variety of red/purple FV intake was associated with lower risks of all-cause and cancer mortality. However, the quantity of FV intake showed no association with all-cause, CVD, and cancer mortality. CONCLUSION: Our findings have first showed that the variety, rather than quantity, in FV intake was associated with a lower risk of mortality in older Chinese. Dietary guidelines may recommend increasing the variety in FV intake, especially green, red/purple, and white FVs in older people.

Association of novel and conventional obesity indices with colorectal cancer risk in older Chinese: a 14-year follow-up of the Guangzhou Biobank Cohort Study.

BACKGROUND: Visceral adiposity index (VAI) and a body shape index (ABSI) were newly developed indices for visceral fat mass. Whether they are superior to conventional obesity indices in predicting colorectal cancer (CRC) remains unclear. We examined the associations of VAI and ABSI with CRC risk, and investigated their performance in discriminating CRC risk compared with conventional obesity indices in the Guangzhou Biobank Cohort Study. METHODS: A total of 28,359 participants aged 50 + years without cancer history at baseline (2003-8) were included. CRC were identified from the Guangzhou Cancer Registry. Cox proportional hazards regression was used to assess the association of obesity indices with the CRC risk. Discriminative abilities of obesity indices were assessed using Harrell's C-statistic. RESULTS: During an average follow-up of 13.9 (standard deviation = 3.6) years, 630 incident CRC cases were recorded. After adjusting for potential confounders, the hazard ratio (95% confidence interval) of incident CRC for per standard deviation increment in VAI, ABSI, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) was 1.04 (0.96, 1.12), 1.13 (1.04, 1.22), 1.08 (1.00, 1.17), 1.15 (1.06, 1.24), 1.16 (1.08, 1.25)and 1.13 (1.04, 1.22), respectively. Similar results for colon cancer were found. However, the associations of obesity indices with risk of rectal cancer were non-significant. All obesity indices showed similar discriminative abilities (C-statistics from 0.640 to 0.645), with WHR showing the highest whilst VAI and BMI the lowest. CONCLUSIONS: ABSI, but not VAI, was positively associated with a higher risk of CRC. However, ABSI was not superior to the conventional abdominal obesity indices in predicting CRC.

Obesity indicators as mediators of the association between age at menopause and blood pressure values.

Having a later age at menopause is associated with having a higher blood pressure (BP) value, but the mediation pathways remain unclear. We quantitatively examined the mediation effects of various obesity indicators using baseline data from phase 4 of the Guangzhou Biobank Cohort Study. The product of coefficients approach and bootstrapping procedures were used to assess the mediation effects of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) on the association between age at menopause and BP values. Age, education, occupation, family income, smoking, drinking, diet, physical activity, age at menarche, number of births, fasting glucose, triglycerides, and high-density lipoprotein cholesterol were adjusted as covariates. Of 5429 women with natural menopause, the mean age and menopausal age were 60.0 (standard deviation = 5.8) and 50.3 (3.1) years, respectively. The prevalence of hypertension was 29.6%. In women with a menopausal age of ≥50 years, BMI, WC, WHR and WHtR showed significant mediation effects on the positive association between menopausal age and BP. The adjusted proportion (95% confidence interval) of the mediation effects for those variables were 26.04% (10.40-116.82%), 25.92% (10.19-108.57%), 14.11% (3.59-62.78%), and 23.17% (8.70-95.81%), respectively, for systolic BP values and 22.59% (10.72-53.60%), 20.67% (9.83-49.31%), 9.21% (2.73-23.92%), and 17.19% (7.56-41.31%) for diastolic BP values. In women with a menopausal age of <50 years, no significant association between age at menopause and systolic/diastolic BP values was found. In conclusion, obesity indicators showed significant mediating effects on the association between having a later age at menopause and having a higher BP value. Further longitudinal studies with detailed and accurate measurements of metabolic changes after menopause and sufficient follow-up are warranted to confirm these results. We demonstrated obesity indicators showed significant mediating effects on the association between later age at menopause (≥50 years) and higher BP.

Association of Multi-Dimensional Factors with Accelerating Age and Constructing a Healthy Lifestyle Index: Guangzhou Biobank Cohort Study.

INTRODUCTION: Ageing process is influenced by multi-dimensional factors collectively. Previous studies examined association of one separate factor with mortality without considering different manifestations of ageing process. We investigated associations of multi-dimensional factors with accelerating age (AA), a proxy to quantify ageing, in older Chinese. METHODS: 9,831 participants from Guangzhou Biobank Cohort Study were included. Four exposure domains of 15 variables including demographic and socio-economic factors, lifestyle factors, stress across the life course, and common diseases were assessed. AA was calculated based on chronological age and eight biomarkers. Traditional multivariable linear and Bayesian Network (BN) models were used. RESULTS: In both traditional and BN models, male sex, smoking, alcohol use, physical inactivity, greater waist circumference, and body mass index (BMI) were associated with higher AA, with the adjusted ß (95% confidence intervals) being 2.75 (2.40-3.09), 1.31 (0.87-1.76), 1.35 (0.55-2.15), 0.64 (0.40-0.88), 0.09 (0.06-0.11), and 0.13 (0.07-0.19) years, respectively. A Healthy Lifestyle Index (HLI) was constructed including the above lifestyle factors (non-smoking, non-alcohol use, physically active, non-central, and non-general obesity) with a point assigned for each. A higher index indicates healthier lifestyle. Compared with participants with an HLI of 5, those with an HLI of 0-2 had 2.90 (2.48-3.32) years older AA. CONCLUSIONS: Male sex, smoking, alcohol use, physical inactivity, greater waist circumference, and BMI were associated with higher AA by 0.09-2.75 years, suggesting that adopting a healthy lifestyle may alleviate process of phenotypic ageing.

Cereal intake and mortality in older Chinese: a 15-year follow-up of a prospective cohort study.

PURPOSE: We examined the association between whole grain and refined grain intake with all-cause, cancer and cardiovascular disease (CVD) mortality using the data from the Guangzhou Biobank Cohort Study. METHODS: 19,597 participants aged 50+ years were recruited from 2003 to 2006 and followed-up until April 2021. Multivariable Cox regression was used to calculate hazard radios (HRs) and 95% confidence intervals (CIs). Substitution analysis was used to replace a serving (50 g/day) of whole grain with a serving of refined grain. RESULTS: During 286,821 person-years of follow-up, 4385 deaths occurred, including 1450 from cancer, 1678 from CVD and 1257 from other causes. Compared with never whole grain intake, the highest intake category of whole grain (> 300 g/week) was associated with lower risk of all-cause (HR 0.90, 95% CI 0.82-0.98) and CVD mortality (HR 0.85, 0.74-0.98). Compared with the low-intake category of refined grain (< 500 g/day), the highest intake category (> 900 g/week) was associated with a lower risk of cancer mortality (HR 0.76, 0.62-0.95), but a higher risk of CVD mortality (HR 1.25, 1.03-1.51). No significant associations were found between whole grain intake and cancer mortality nor refined grain and all-cause mortality. The HRs of all-cause, cancer and CVD mortality substituting a serving of whole grain for refined grain were 0.96 (0.94-0.99), 1.01 (0.99-1.02) and 0.95 (0.90-0.99), respectively. CONCLUSION: We have first shown that in older Chinese, whole grain intake was associated with lower risk of all-cause and CVD mortality. Our results suggest that intake of whole grain of at least 300 g/week and refined grain of ≤ 900 g/day might be suitable for older Asian. Substituting 50 g/day of whole grain for refined grain was associated with a 4-5% lower risk of all-cause and CVD mortality.

Hearing loss and depressive symptoms in older Chinese: whether social isolation plays a role.

BACKGROUND: Existing evidence links hearing loss to depressive symptoms, with the extent of association and underlying mechanisms remaining inconclusive. We conducted a cross-sectional study to examine the association of hearing loss with depressive symptoms and explored whether social isolation mediated the association. METHODS: Eight thousand nine hundred sixty-two participants from Guangzhou Biobank Cohort Study were included. Data on self-reported hearing status, the 15-item Geriatric Depression Scale (GDS-15), social isolation and potential confounders were collected by face-to-face interview. RESULTS: The mean (standard deviation) age of participants was 60.2 (7.8) years. The prevalence of poor and fair hearing was 6.8% and 60.8%, respectively. After adjusting for age, sex, household income, education, occupation, smoking, alcohol use, self-rated health, comorbidities, compared with participants who had normal hearing, those with poor hearing (ß = 0.74, 95% confidence interval (CI) 0.54, 0.94) and fair hearing (ß = 0.59, 95% CI 0.48, 0.69) had higher scores of GDS-15. After similar adjustment, those with poor hearing (odds ratio (OR) = 2.13, 95% CI 1.65, 2.74) or fair hearing (OR = 1.68, 95% CI 1.43, 1.99) also showed higher odds of depressive symptoms. The association of poor and fair hearing with depressive symptoms attenuated slightly but not substantially after additionally adjusting for social isolation. In the mediation analysis, the adjusted proportion of the association mediated through social isolation was 9% (95% CI: 6%, 22%). CONCLUSION: Poor hearing was associated with a higher risk of depressive symptoms, which was only partly mediated by social isolation. Further investigation of the underlying mechanisms is warranted.

Associations of face-to-face and non-face-to-face social isolation with all-cause and cause-specific mortality: 13-year follow-up of the Guangzhou Biobank Cohort study.

BACKGROUND: Although social isolation has been associated with a higher mortality risk, little is known about the potential different impacts of face-to-face and non-face-to-face isolation on mortality. We examined the prospective associations of four types of social isolation, including face-to-face isolation with co-inhabitants and non-co-inhabitants, non-face-to-face isolation, and club/organization isolation, with all-cause and cause-specific mortality separately. METHODS: This prospective cohort study included 30,430 adults in Guangzhou Biobank Cohort Study (GBCS), who were recruited during 2003-2008 and followed up till Dec 2019. RESULTS: During an average of 13.2 years of follow-up, 4933 deaths occurred during 396,466 person-years. Participants who lived alone had higher risks of all-cause (adjusted hazard ratio (AHR) 1.24; 95% confidence interval (CI) 1.04-1.49) and cardiovascular disease (CVD) (1.61; 1.20-2.03) mortality than those who had ≥ 3 co-habitant contact after adjustment for thirteen potential confounders. Compared with those who had ≥ 1 time/month non-co-inhabitant contact, those without such contact had higher risks of all-cause (1.60; 1.20-2.00) and CVD (1.91; 1.20-2.62) mortality. The corresponding AHR (95% CI) in participants without telephone/mail contact were 1.27 (1.14-1.42) for all-cause, 1.30 (1.08-1.56) for CVD, and 1.37 (1.12-1.67) for other-cause mortality. However, no association of club/organization contact with the above mortality and no association of all four types of isolation with cancer mortality were found. CONCLUSIONS: In this cohort study, face-to-face and non-face-to-face isolation were both positively associated with all-cause, CVD-, and other-cause (but not cancer) mortality. Our finding suggests a need to promote non-face-to-face contact among middle-aged and older adults.

Obesity indicators as mediators of association between daytime napping and type 2 diabetes mellitus: the Guangzhou Biobank Cohort Study.

OBJECTIVE: To examine the mediating effect of obesity indicators on the association between daytime napping and type 2 diabetes mellitus (T2DM) qualitatively and quantitatively using baseline data from the Guangzhou Biobank Cohort Study. METHODS: Twenty-nine thousand three hundred fifty-five participants aged 50+ years were included in this cross-sectional study. Mediation analysis was used to assess the mediating effect of body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) on the association between daytime napping and T2DM after adjustment for sex, age, education, occupation, smoking status, alcohol use and physical activity. RESULTS: The mean (standard deviation) age of participants was 61.5 ( 7.1) years. The prevalence of T2DM and daytime napping was 12.5% and 65.2%, respectively. After adjustment for potential confounders, WC, WHR and WHtR showed partial mediating effects on the association between daytime napping and T2DM, with the proportion (95% confidence interval) of mediation effect being 10.17% (8.14-14.43%), 14.91% (11.95-21.24%) and 9.36% (7.49-13.29%), respectively. No mediating effect of BMI or HC on the association between daytime napping and T2DM was found. CONCLUSIONS: Our results showed significant mediating effects of WC, WHR and WHtR on the association between daytime napping and T2DM, suggesting that waist circumference management could be important in daytime nappers.

A Simple Model for Predicting 10-Year Cardiovascular Risk in Middle-Aged to Older Chinese: Guangzhou Biobank Cohort Study.

The aim of this paper is to develop 10-year cardiovascular disease (CVD) risk prediction models for the contemporary Chinese populations based on the Guangzhou Biobank Cohort Study (GBCS) and to compare its performance with models based on Framingham's general cardiovascular risk profile and the Prediction for Atherosclerotic CVD Risk in China (China-PAR) project. Subjects were randomly classified into the training (n = 15,000) and validation (n = 12,721) sets. During an average of 12.0 years' follow-up, 3,732 CVD events occurred. A 10-year sex-specific CVD risk prediction model including age, systolic blood pressure, use of antihypertensive medication, smoking, and diabetes was developed. Compared with the Framingham and China-PAR models, the GBCS model had a better discrimination in both women (c-statistic 0.72, 95% CI 0.71-0.73) and men (c-statistic 0.68, 95% CI 0.67-0.70), and the risk predicted was closer to the actual risk. This prediction model would be useful for identifying individuals at higher risks of CVD in contemporary Chinese populations.

Brain-derived neurotrophic factor gene variants and obesity in former smokers.

OBJECTIVE: From genome-wide association studies, brain-derived neurotrophic factor (BDNF) locus on chromosome 11 was the only SNP associated with both smoking and body mass index (BMI) in European, African and Asian population. This study aims to explore the unique genetic predisposition to obesity in former smokers by examining the effects of BDNF on BMI and waist circumference (WC). METHODS: The study design is case-control study with a cohort validation in supplementary. We included 15,072 ethnic Chinese participants in the Guangzhou Biobank Cohort Study (GBCS) with data of four BDNF SNPs related to both BMI and smoking behavior. We used baseline smoke exposure data in 2003-2007 and follow-up outcomes of general obesity (by BMI) and central obesity (WC) in 2008-2012. Odds ratios (ORs) and 95% confidence intervals (CIs) for general obesity and central obesity associated with these SNPs were derived from logistic regression. RESULTS: Of 15,072 participants (3169 men and 11,903 women), 1664 (11.0%) had general and 7868 (52.2%) had central obesity. In 1233 former smokers, the rs6265 GG, versus AA, genotype was associated with higher risks of general obesity (OR = 1.79, 95% CI = 1.06-3.01) and central obesity (OR = 2.08, 95% CI = 1.47-2.92) after adjustment. These associations were not significant in never or current smokers. In former heavy (≥20 cigarettes/day) smokers, the rs6265 GG genotype showed a higher odds for general obesity (OR = 2.15, 95% CI = 1.05-4.40), while no association was found in former light (1-9 cigarettes/day) smokers. Similar results were found for the association of rs6265 with central obesity and for the associations of other two BDNF SNPs (rs4923457 and rs11030104) with both general and central obesity. CONCLUSIONS: We firstly identified the genetic predisposition (BDNF SNPs) to general and central obesity in former smokers, particularly in former heavy smokers. The different associations of the SNPs for general/central obesity in different smoke exposure groups may be related to the competitive performance of the sites and epigenetic modification, which needs further study.

Smoking and nasopharyngeal cancer: individual data meta-analysis of six prospective studies on 334 935 men.

BACKGROUND: The role of smoking in nasopharyngeal carcinoma (NPC) remains uncertain, especially in endemic regions. We conducted an individual participant data (IPD) meta-analysis of prospective cohort studies to investigate the associations between smoking exposure and risk of NPC. METHODS: We obtained individual participant data of 334 935 male participants from six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore. We used one- and two-stage approaches IPD meta-analysis and Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of NPC for smoking exposure adjusting for age and drinking status. RESULTS: During 2 961 315 person-years of follow-up, 399 NPC evens were ascertained. Risks of NPC were higher in ever versus never smokers (HRone-stage = 1.32, 95% CI = 1.07-1.63, P = 0.0088; HRtwo-stage = 1.27, 1.01-1.60, 0.04). These positive associations appeared to be stronger in ever smokers who consumed 16+ cigarettes/day (HRone-stage = 1.67, 95% CI = 1.29-2.16, P = 0.0001), and in those who started smoking at age younger than 16 (2.16, 1.33-3.50, 0.0103), with dose-response relationships (P-values for trend = 0.0028 and 0.0103, respectively). Quitting (versus daily smoking) showed a small reduced risk (stopped for 5+ years: HRone-stage = 0.91, 95% CI = 0.60-1.39, P = 0.66; for former smokers: HRtwo-stage = 0.84, 0.61-1.14, 0.26). CONCLUSIONS: This first IPD meta-analysis from six prospective cohorts in endemic regions has provided robust observational evidence that smoking increased NPC risk in men. NPC should be added to the 12-16 cancer sites known to be tobacco-related cancers. Strong tobacco control policies, preventing young individuals from smoking, would reduce NPC risk in endemic regions.

Physicians' very brief (30-sec) intervention for smoking cessation on 13 671 smokers in China: a pragmatic randomized controlled trial.

BACKGROUND AND AIMS: Three to 10 minutes of smoking cessation advice by physicians is effective to increase quit rates, but is not routinely practised. We examined the effectiveness of physicians' very brief (approximately 30 sec) smoking cessation intervention on quit rates among Chinese outpatient smokers. DESIGN: A pragmatic, open-label, individually randomized controlled trial. SETTING: Seventy-two medical outpatient departments of hospitals and/or community health centers in Guangdong, China. PARTICIPANTS: Chinese adults who were daily cigarette smokers (n = 13 671, 99% males) were invited by their physician to participate during outpatient consultation. Smokers who were receiving smoking cessation treatment or were judged to need specialist treatment for cessation were excluded. INTERVENTIONS: The intervention group (n = 7015) received a 30-sec intervention including physician's very brief advice, a leaflet with graphic warnings and a card with contact information of available cessation services. The control group (n = 6656) received a very brief intervention on consuming vegetables and fruit. A total of 3466 participants in the intervention group were further randomized to receive a brief booster advice from trained study personnel via telephone 1 month following their doctor visit. MEASUREMENTS: The primary outcome was self-reported 7-day point prevalence abstinence (PPA) in the intervention and control groups at the 12-month follow-up. Secondary outcomes included self-reported 30-day abstinence and biochemically validated abstinence at 12-month follow-up. FINDINGS: By intention-to-treat, the intervention (versus control) group had greater self-reported 7-day abstinence [9.1 versus 7.8%, odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.03-1.26, P = 0.008] and 30-day abstinence (8.0 versus 6.9%, OR = 1.14, 95% CI = 1.03-1.27, P = 0.01) at 12-month follow-up. The effect size increased when only participants who received the intervention from compliant physicians were included (7-day PPA, OR = 1.42, 95% CI = 1.11-1.74). The group difference in biochemically validated abstinence was small (0.8 versus 0.8%, OR = 1.00, 95% CI = 0.71-1.42, P = 0.99). CONCLUSION: A 30-sec smoking cessation intervention increased self-reported abstinence among mainly male smokers in China at 12-month follow-up (risk difference = 1.3%), and should be feasible to provide in most settings and delivered by all health-care professionals.

Adiposity change and mortality in middle-aged to older Chinese: an 8-year follow-up of the Guangzhou Biobank Cohort Study.

OBJECTIVE: To examine the associations of change in body mass index (BMI) and waist circumference (WC) over an average of 4 years with subsequent mortality risk in middle-aged to older Chinese. DESIGN: Prospective cohort study based on the Guangzhou Biobank Cohort Study. SETTING: Community-based sample. PARTICIPANTS: 17 773 participants (12 956 women and 4817 men) aged 50+ years. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome measure was all-cause mortality. Secondary outcome measures were cardiovascular disease (CVD) and cancer mortality. Causes of death were obtained via record linkage, and coded according to the International Classification of Diseases (tenth revision). RESULTS: 1424 deaths (53.4% women) occurred in the 17 773 participants (mean age 61.2, SD 6.8 years) during an average follow-up of 7.8 (SD=1.5) years, and 97.7% of participants did not have an intention of weight loss . Compared with participants with stable BMI, participants with BMI loss (>5%), but not gain, had a higher risk of all-cause mortality (HR=1.49, 95% CI 1.31 to 1.71), which was greatest in those who were underweight (HR=2.45, 95% CI 1.31 to 4.59). Similar patterns were found for WC. In contrast, for participants with a BMI of ≥27.5 kg/m2, BMI gain, versus stable BMI, was associated with 89% higher risk of all-cause mortality (HR=1.89, 95% CI 1.25 to 2.88), 72% higher risk of CVD mortality (HR=1.72, 95% CI 0.80 to 3.72) and 2.27-fold risk of cancer mortality (HR=2.27, 95% CI 1.26 to 4.10). CONCLUSION: In older people, unintentional BMI/WC loss, especially in those who were underweight was associated with higher mortality risk. However, BMI gain in those with obesity showed excess risks of all-cause and cancer mortality, but not CVD mortality. Frequent monitoring of changes in body size can be used as an early warning for timely clinical investigations and interventions and is important to inform appropriate health management in older Chinese.

Glycaemia and hand grip strength in aging people: Guangzhou biobank cohort study.

BACKGROUND: There is a link between hyperglycemia and mechanical functions of muscle. However, existing evidence of the association between hyperglycemia and weaker muscle strength is limited and inconsistent. We examined whether glycemic status was associated with relative grip strength (RGS) in older Chinese. METHODS: In 2008-2012, 9180 participants (2516 men and 6664 women) from the Guangzhou Biobank Cohort Study had fasting and 2-h post-load glucose measured. Glycemic status was categorized as normoglycaemia, prediabetes (i.e., impaired fasting glucose and/or impaired glucose tolerance) and diabetes. RGS was assessed using a Jamar Hydraulic Hand Dynamometer divided by body mass index. General linear model was used to assess the association of glycemic status with RGS. RESULTS: After adjusting for age, smoking status, alcohol use, physical activity, health status, body fat percentage and waist circumference, in men, hyperglycemia was associated with a lower RGS, with the RGS being 1.38 (95% confidence interval (CI) = 1.34, 1.42) in normoglycaemia, 1.35 (95% CI = 1.30, 1.39) in prediabetes, 1.33 (95% CI = 1.29, 1.38) in newly diagnosed diabetes and 1.32 (95% CI = 1.27, 1.37) in known diabetes (P for trend < 0.001). The association of glycemic status with RGS was non-significant in women. Among the normoglycaemic group, no association was found between fasting glucose and RGS in men, whereas a significantly inverse association was found in women, with adjusted ß for RGS per mmol/l increase in fasting glucose being - 0.05 to - 0.04 (P values from 0.002 to 0.03). CONCLUSIONS: Higher fasting glucose was associated with reduced grip strength in a dose-response manner, and the association was significant even in women with normoglycaemia. Our findings suggest that lowering glucose across the whole range might be important in preserving muscle strength, especially in aging women.

Development and validation of a prediction model for airflow obstruction in older Chinese: Guangzhou Biobank Cohort Study.

OBJECTIVE: To develop and validate a prediction model for airflow obstruction (AO) in older Chinese. DESIGN: Multivariable logistic regression analysis in large population cohort of Chinese aged ≥50 years. PARTICIPANTS: Model development: 8762 Chinese aged ≥50 years were selected from the early phase recruits to the Guangzhou Biobank Cohort Study (GBCS) (recruited from September 2003 to May 2006). Internal validation: 100 bootstrap samples drawn with replacement from the development sample. External validation: 8395 Chinese aged ≥50 years from later phase GBCS (recruited from September 2006 to January 2008). OUTCOMES: AO was defined by a forced expiratory volume in 1 s/forced vital capacity ratio < lower limits of normal. RESULTS: 839 (9.6%) and 764 (9.1%) individuals had AO in the development and temporal validation samples respectively. The predictors in the prediction model included sex, age, body mass index groups, smoking status, presence of respiratory symptoms, and history of asthma. Model development and validation was stratified by sex. Model performance including calibration (calibration-in-the-large -0.017 vs. -0.157; and calibration slope 0.88 vs. 1.02), discrimination (C-statistic 0.72 vs. 0.63 with 95% confidence interval 0.69-0.75 vs. 0.62-0.73) and clinical usefulness (decision curve analysis) in the external temporal validation sample were more satisfactory in men than that in women. Prediction models with risk thresholds (13% in men and 7% in women) and easy-to-use nomograms were developed to assess the probability of AO. CONCLUSION: The diagnostic models based on readily available epidemiologic and clinical information with satisfactory performance can assist physicians to identify older individuals at high risk of AO and may improve the efficiency of spirometry for active case finding. Further validation beyond the Chinese population is warranted.