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.

Association of Testosterone and Sex Hormone-Binding Globulin With All-Cause and Cardiovascular Disease Mortality in Older Chinese Men

BACKGROUND

The associations of high and low testosterone with all-cause and cardiovascular disease (CVD) mortality risk in men are conflicting. Our objective was to examine associations of total testosterone, free testosterone, bioavailable testosterone, and sex hormone-binding globulin (SHBG) with all-cause and CVD mortality in older Chinese men.

METHODS

Total testosterone and SHBG were assayed, and free testosterone and bioavailable testosterone were calculated using Vermeulen formula. Cox proportional hazards regression was used to assess the associations with risks of all-cause and CVD mortality, giving hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Of 3 948 men aged 50+ years, 949 deaths (312 CVD) occurred during an average 10.5-year follow-up. After multivariable adjustments, the highest, versus the third, quartile of total testosterone and free testosterone were associated with higher all-cause mortality risk (1.17 [0.97-1.41] and 1.45 [1.20-1.74], respectively), whereas free testosterone was associated with higher CVD mortality risk (1.88 [1.33-2.66]). Similar positive associations were found for bioavailable testosterone and all-cause mortality risk (1.27 [1.05-1.54]). Lower SHBG (quartile 1 vs quartile 3) was associated with higher all-cause and CVD mortality risk (1.25 [1.04-1.52] and 1.28 [1.08-1.52], respectively). Consistent associations were observed in relatively healthy men and men excluded death during the first year.

CONCLUSIONS

Higher total testosterone, free testosterone, and bioavailable testosterone were associated with higher all-cause mortality in older men, higher free testosterone was associated with higher CVD mortality whilst lower SHBG was associated with higher all-cause and CVD mortality. Clarification and confirmation of causality require further mechanistic studies.

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 adverse childhood experiences with anemia in older Chinese: Guangzhou Biobank Cohort Study

To examine the association of adverse childhood experiences (ACEs) with anemia among older people. 24,116 participants aged 50 years or above were recruited. Multivariable linear and logistic regression was used to assess the associations of self-reported ACEs number with hemoglobin concentrations (g/dL) and presence of anemia. Older individuals with two or more ACEs, versus no ACEs, showed lower hemoglobin concentrations (β =  - 0.08 g/dL, 95% confidence intervals (CI) - 0.12 to - 0.03) and higher odds of anemia (odds ratio = 1.26, 95% CI 1.01-1.59). A more pronounced association between ACEs and anemia in the lower education group was found, while the association became non-significant in those with higher education (P for ACEs-education interaction = 0.02). ACEs was associated with anemia in older people, and the association was stronger in those with lower education, highlighting the significance of early-life psychological stressors assessment and consideration of education background in geriatric care.

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 insulin resistance and glycemic measures with major abnormal electrocardiogram in older Chinese: Cross-sectional analysis based on the Guangzhou Biobank Cohort study

AIMS

To examine whether insulin resistance (IR) and glycemic measures were associated with major abnormal electrocardiogram (MA-ECG) and its specific abnormalities in the general population.

METHODS

Twelve-lead ECG measurements were performed on 21,720 participants without cardiovascular disease (5,918 men) from the Guangzhou Biobank Cohort Study. The participants were aged 50 years or above (mean age 61.6, standard deviation 7.1 years). Logistic regression was used to assess the associations of IR and glycemic measures with MA-ECG and specific abnormalities.

RESULTS

Ln-fasting insulin was significantly associated with MA-ECG and ST-T abnormalities (adjusted odds ratio = 1.52, 95 % confidence interval = 1.15-2.02 and 1.83, 1.37-2.45, respectively, for per standard deviation), which were stronger than those of TyG index with MA-ECG (1.08, 1.04-1.13) and ST-T abnormalities (1.16, 1.11-1.22). Ln-fasting insulin had association with Q wave abnormalities (3.19, 1.52-6.67). The association of TyG index with prolonged QTc varied by sex and obesity (P for interaction ≤ 0.01). Participants with diabetes had stronger associations of ln-fasting plasma glucose with ECG abnormalities than those without.

CONCLUSIONS

IR and glycemic measures were associated with MA-ECG, ischemia and prolonged QTc in older Chinese, especially in women, those with obesity, and those with diabetes. These findings underscore the importance of regular evaluations for these groups.

Associations Between Sleep Traits and Social Isolation: Observational and Bidirectional Mendelian Randomization Study

Social isolation has been found associated with multiple sleep traits in conventional observational studies. However, whether this association is causal and if so, its direction is uncertain. We analyzed the association between social isolation and multiple sleep traits in 30 430 participants from the Guangzhou Biobank Cohort Study. In bidirectional Mendelian randomization, we used 6, 17, and 11 single nucleotide polymorphisms associated with attendance at sports club/gym, religious group, and pub/social club from the UK Biobank (n = 452 302), respectively, and 152 single nucleotide polymorphisms associated with insomnia from the combination of UK Biobank and 23andme (n = 1 331 010). Observationally in the Guangzhou Biobank Cohort Study, insomnia (yes/no) (beta = 0.12, 95% confidence interval (CI) 0.10-0.16) and poor sleep quality (yes/no) (beta = 0.12, CI: 0.08-0.15), but not sleep duration and chronotype, were associated with a higher social isolation score (severe social isolation). In bidirectional MR, genetically predicted insomnia decreases the odds of attendance at sports club/gym (beta = 0.98, CI: 0.98-0.99) and religious groups (beta = 0.99, CI: 0.98-0.99), but not pub/social club. However, these 3 types of social activity were not associated with insomnia. Our results support the causal effects of insomnia on social activity. Further clinical investigations into the utility of insomnia treatment in alleviating social isolation are needed.

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.

Association of perceived stress with memory decline in older Chinese: The Guangzhou Biobank Cohort Study

BACKGROUND

Previous studies on associations of perceived stress with poor memory performance in older adults showed inconsistent results. We examined the prospective associations of perceived stress with memory decline using data from Guangzhou Biobank Cohort Study (GBCS).

METHODS

Perceived stress was measured by the Perceived Stress Scale (PSS) at baseline (2003-2006), with greater scores indicating greater stress. Memory function was measured by delayed 10-word recall test (DWRT) and immediate 10-word recall test (IWRT), with greater scores indicating better performance, at baseline and follow-up (2008-2012) examinations, analyzed as mean annual change in scores.

RESULTS

9656 participants (72 % women) with mean age 61.6 (standard deviation = 6.4) years were included. During an average of 4.4 years of follow-up, after adjusting for confounders, each one-point greater PSS score was associated with mean annual decline in DWRT scores (β (95 % CI) = -0.005 (-0.008 to -0.002)). Greater Perceived Helplessness (PH) scores, but not Perceived Self-efficacy scores, was associated with greater mean annual decline in DWRT and IWRT scores (β (95 % CI) = -0.005 (-0.009 to -0.001) and - 0.012 (-0.018 to -0.005), respectively), and similar patterns were observed in five out of seven PH items (βs from -0.02 to -0.07). Interaction analysis showed that the association of greater PSS with greater decline in DWRT scores was observed only in those with low family income (β (95 % CI) = -0.08 (-0.13 to -0.04), P for interaction = 0.03).

CONCLUSIONS

Greater perceived stress was associated with a greater decline in delayed recall memory, especially in those with low family income.

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 (β=-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 (β=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 (β=-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.

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.

Persistence of social isolation and mortality: 10-year follow-up of the Guangzhou Biobank Cohort study

Although social isolation has been associated with higher mortality risk, the associations of persistence of social isolation with mortality are unclear. We investigated the prospective associations of intermittent and persistent social isolation with all-cause and cause-specific mortality, considering the social contact types (face-to-face and non-face-to-face). 30,518 participants were recruited in 2003-2008 initially and 18,104 participants with re-assessed social isolation information in 2008-2012 were followed up to Dec 2019 in Guangzhou Biobank Cohort Study (GBCS). During an average of 9.7 years of follow-up, 2,119 deaths occurred. The isolation at baseline survey, isolation at second survey and persistent isolation were positively associated with all-cause mortality in the minimal adjusted model (adjusted hazard ratio (AHR) =1.24, 95% CI 1.12-1.38, 1.11, 1.00-1.23 and 1.23, 1.05-1.43, respectively). Totally 47.2% of the risk was explained by health status, SEP, and biological, behavioural and psychological factors. Persistent isolation from face-to-face with co-inhabitants, versus no isolation, was associated with higher risks of all-cause (HR=1.40, 1.09-1.81) and CVD (subdistribution hazard ratio (SHR)=1.92, 1.31-2.81) mortality in fully adjusted model. Our study showed that intermittent and persistent isolation were generally associated with higher risks of mortality, and the risks were even higher in those with persistent face-to-face isolation with co-inhabitants.

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.

[Study on the relationship between the age at natural menopause and postmenopausal metabolic syndrome]

To explore the relationship between the early or delayed age at natural menopause and metabolic syndrome (MS) in women. A total of 4 734 natural menopausal women who completed the baseline survey from November 2017 to January 2020 in the Guangzhou Middle-aged and Elderly Chronic Disease Prospective Cohort Study were selected in this cross-sectional study. Data on general demographic characteristics, disease history and female physiological health indicators were collected. Logistic regression model and restricted cubic spline curve were used to analyze the relationship between the age at natural menopause and MS. The results showed that the mean age of the subjects was (60±6) years old. The median (Q₁,Q₃) age at natural menopause was 50 (49, 52) years old, and the prevalence of MS was 14.8%(699/4 734). After adjusting for confounders, the age at natural menopause was closely related to MS in an approximate"U"shape. Compared with the group of normal age at natural menopause, the early age at menopause (OR=1.52, 95%CI: 1.12-2.06) and delayed age at menopause (OR=1.77, 95%CI: 1.36-2.30) had a higher risk of MS. In the group with time since menopause ≤6 years and 7-9 years, the risk of MS in the group with delayed age at menopause was 2.40 times (95%CI: 1.54-3.75) and 2.19 times (95%CI: 1.11-4.31) higher than that in the group with normal menopausal age, respectively. In conclusion, the early and delayed age at natural menopause increased the risk of MS. The increased risk of MS in delayed age at natural menopause mainly occurred within 10 years since menopause.

Low-carbohydrate diet score and the risk of stroke in older people: Guangzhou Biobank Cohort Study and meta-analysis of cohort studies

OBJECTIVES

To our knowledge, evidence regarding the association of a low-carbohydrate diet (LCD) with the risk for stroke is limited. The aim of this study was to examine the association between an LCD and stroke in a population with relatively high-carbohydrate intake and risk for stroke and use a meta-analysis to update the evidence.

METHODS

The study included 19 850 participants aged ≥50 y without stroke history at baseline in the Guangzhou Biobank Cohort Study. LCD score was calculated based on the percentage of energy from carbohydrate, protein, and fat (range 0-30 points), with a higher score indicating a lower intake of carbohydrate and a higher intake of fat and protein.

RESULTS

During an average follow-up of 13.1 y, 1661 stroke events and deaths occurred, including 1255 ischemic strokes. The second, versus the lowest quartile of animal-based LCD scores, were associated with lower risks for all stoke and ischemic stroke (hazards ratio [HR], 0.87; 95% confidence interval [CI], 0.77-0.997, and HR, 0.83; 95% CI, 0.72-0.97). Non-significant associations of plant-based or total LCD scores with the risk for stoke were found.

CONCLUSIONS

In a population consuming high levels of carbohydrates and low levels of protein and fat, a moderate level of animal-based LCD, but not plant-based LCD, was associated with a lower risk for stroke.

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 β (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.

[Clinical and endoscopic characteristics of gastrointestinal mantle cell lymphoma]

Objective: To study the clinical and endoscopic features of mantle cell lymphoma (MCL). Methods: The clinical data and endoscopic characteristics of 20 patients with gastrointestinal MCL treated in the Affiliated Hospital of Zunyi Medical University and the Digestive Endoscopy Center of Guizhou Medical University from January 2011 to January 2021 were collected, and the histological and immunohistochemical characteristics of the tumor were observed. Meanwhile, 44 cases of non-gastrointestinal MCL in the above two hospitals in the same period were also enrolled. The clinical and endoscopic differences between the two groups were compared. Results: Among the 20 patients with gastrointestinal MCL, the male to female ratio was 4∶1 (16/4), the average age was (60.3±9.7) years, and 11 patients (55.0%, 11/20) were over 60 years old. The main clinical manifestations of 20 patients at the onset of the disease were bloody stool or black stool in 9 cases (45.0%), abdominal pain in 8 cases (40.0%). Moreover, 5.0% (1/20) had B symptoms (fever, night sweat and weight loss). The most frequently involved site was colorectum (50.0%). Endoscopic findings showed mucosal polypoid lesions in 13 cases (65.0%, 13/20), involving multiple intestinal segments, with polyp diameter of 0.2-3.5 cm. Two cases (10%) were in stage Ⅲ and 18 cases (90%) were in stage Ⅳ according to Ann Arbor staging. Seven cases (35.0%, 7/20) had the involvement of the peritoneal and retroperitoneal lymph nodes, 9 cases (45.0%, 9/20) had the involvement of the superficial lymph nodes in 45.0% (9/20), and 4 cases (20%, 4/20) had other extranodal invasion. Splenomegaly accounted for 35.0% (7/20). CD20, Bcl-2 and CD5 were positive or strongly positive in all gastrointestinal MCL tumor cells in 20 cases. Cyclin D1 was positive or strongly positive, accounting for 90.0% (18/20). The sex-determining region of Y chromosome-related high-mobility-group box 11 (SOX11) was positive or strongly positive, accounting for 65.0% (13/20). The positive index of Ki-67 was 5%-80%. Twenty cases (100%, 20/20) were followed up. The median follow-up was 41.2 months (1-74 months). There was no significant difference in the 3-year overall survival rate between the gastrointestinal MCL patients (70.0%) and non-gastrointestinal MCL patients (72.7%) (χ²=0.051, P=0.822). Conclusions: Abdominal discomfort is the main symptom of gastrointestinal MCL, which often occurs in the colorectum and often presents with multiple polypoid lesions. There are relatively few cases with B symptoms and extranodal invasion, and the prognosis is not different from that of patients with non-gastrointestinal MCL.

Association of alcohol use with memory decline in middle-aged and older Chinese: a longitudinal cohort study

BACKGROUND

Previous studies on associations of alcohol use with memory decline showed inconclusive results. We examined these associations using longitudinal data from the Guangzhou Biobank Cohort Study (GBCS) and explored whether these associations varied by sex and age group.

METHODS

Memory function was assessed by delayed 10-word recall test (DWRT) and immediate 10-word recall test (IWRT) at both baseline (2003-2008) and follow-up (2008-2012) examinations, expressed as the mean annual change and mean annual rate of change in scores. Memory cognitive impairment was defined by DWRT scores of less than 4. Multivariable linear regression models and restricted cubic spline were used for data analysis.

RESULTS

Of 14,827 participants without memory cognitive impairment at baseline, 90.2% were never or occasional drinkers, 5% moderate drinkers, 1.5% excessive drinkers, and 3.3% former drinkers. The mean (standard deviation) age was 60.6 (6.6) years old. During an average of 4.1 years follow-up, 1000 (6.7%) participants developed memory cognitive impairment. After adjusting for confounders, compared with never or occasional drinkers, moderate and excessive drinkers had significant decline in DWRT scores (β, 95% confidence interval (CI) = -0.04 (-0.08 to -0.01), and - 0.07 (-0.14 to 0.01), respectively), and IWRT scores (β, 95% CI = -0.10 (-0.19 to -0.01), and - 0.15 (-0.30 to 0.01), respectively) annually. With respect to the mean annual rate of change, moderate and excessive drinkers also showed greater decline in DWRT scores (β, 95% CI = -1.02% (-1.87% to -0.16%), and - 1.64% (-3.14% to -0.14%), respectively). The associations did not vary by sex and age group (all P values for interaction ≥ 0.10).

CONCLUSION

Compared to never or occasional alcohol use, moderate and excessive alcohol users had greater memory decline and the associations did not vary by sex and age group.

Chronotype and cognitive function: Observational study and bidirectional Mendelian randomization

BACKGROUND

Association has been found between chronotype and cognitive function in conventional observational studies but whether this association is causal and if so, its direction, is uncertain. There are also concerns among people with later chronotype that their habits may be detrimental to cognitive function.

METHODS

We analyzed the association between chronotype (measured as sleep midpoint) and cognitive function (measured by Mini-Mental Status Examination (MMSE) and Delayed Word Recall Test (DWRT)) using multivariable linear regression on 14,582 participants in the Guangzhou biobank cohort study (GBCS) from 2008 to 2012. Using bidirectional Mendelian randomization, we used 207 single nucleotide polymorphisms (SNPs) associated with chronotype from the combination of UK Biobank and 23andMe (n = 697,828), and 127 SNPs associated with cognitive function from the combination of UK Biobank and COGENT consortium (n = 257,841).

FINDINGS

Observationally in GBCS, later chronotype was associated with better cognitive function (MMSE scores: β = 0.14 per hour; 95% confidence interval (CI), 0.09-0.19; DWRT scores: β = 0.07 per hour; 95% CI, 0.04-0.11). Bidirectional MR showed genetic predisposition to early, versus later, chronotype was not associated with cognitive function using inverse-variance weighted (β = -0.02; 95% CI, -0.05 to 0.01). However, better cognitive function was associated with decreased odds of early chronotype (UK Biobank: odds ratio = 0.88 per standardized score; 95% CI, 0.83-0.93; 23andMe: 0.87 per standardized score; 95% CI, 0.80-0.95).

INTERPRETATION

It is a reassuring finding for adults with later chronotype who may be concerned if such a habit has a negative impact on cognitive function.

FUNDING

The National Natural Science Foundation of China; Natural Science Foundation of Guangdong; The University of Hong Kong Foundation for Educational Development and Research; The Health Medical Research Fund in Hong Kong; The University of Birmingham, UK.

Association of alcohol drinking with incident type 2 diabetes and pre-diabetes: The Guangzhou Biobank Cohort Study

AIMS

We examined associations of baseline alcohol drinking with incident type 2 diabetes (T2D) or impaired fasting glucose (IFG), and explore whether the associations were modified by genetic polymorphisms of aldehyde dehydrogenase-2 (ALDH2) and alcohol dehydrogenase-1B (ADH1B).

MATERIALS AND METHODS

All participants were aged 50+ (mean = 60.45; standard deviation = 6.88) years. Information of alcohol consumption was collected at baseline from 2003 to 2008. Incident T2D was defined as fasting glucose ≥7.0 mmol/L or post-load glucose ≥11.1 mmol/L at follow-up examination (2008-2012), self-reported T2D and/or initiation of hypoglycaemia medication or insulin during follow-up. Impaired fasting glucose was defined as fasting glucose ≥5.6 mmol/L and <7 mmol/L.

RESULTS

Of 15,716 participants without diabetes and 11,232 participants without diabetes and IFG at baseline, 1624 (10.33%) developed incident T2D and 1004 (8.94%) developed incident IFG during an average 4 years of follow-up. After multivariable adjustments, compared with never drinking, occasional or moderate alcohol drinking was not associated with risk of incident hyperglycaemia (T2D + IFG) (odds ratio (OR) = 1.10, 95% confidence interval (CI) 0.95-1.27, and 0.90 (0.69-1.18), respectively), whereas heavy alcohol drinking was associated with a higher risk of incident hyperglycaemia (T2D + IFG) (OR = 1.82, 95% CI 1.24-2.68). No interactions of sex, overweight/obesity and genetic polymorphisms of ADH1B/ALDH2 genes with alcohol drinking on incident T2D and/or IFG were found (P for interaction from 0.12 to 0.85).

CONCLUSIONS

Our results support a detrimental effect of heavy alcohol use on IFG and T2D. No protective effect was found for those carrying lower risk alleles for ADH1B/ALDH2 genes.

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 (β = 0.74, 95% confidence interval (CI) 0.54, 0.94) and fair hearing (β = 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03311-0.

Association between spicy foods consumption and cardiovascular disease risk factors: Guangzhou Biobank Cohort Study

Background

Evidence regarding the association of spicy foods intake with cardiovascular disease (CVD) risk factors was less clear, especially in those with diabetes. We hereby examined the association of spicy foods intake with CVD risk factors in older Chinese.

Methods

Thirty thousand three hundred twenty-five participants (72.34% women) aged 50+ years were recruited in the Guangzhou Biobank Cohort Study from 2003 to 2008. Information of spicy foods intake and disease history was collected by face-to-face interview. CVD risk factors were measured and treated as continuous variables. Diabetes was defined by a fasting plasma glucose (FPG) ≥7.0 mmol/L and/or self-reported physician-diagnosed diabetes.

Results

Of 30,325 participants, 12.9% consumed spicy foods regularly. After adjusting for multiple confounders, participants who consumed spicy foods of 5–7 days/week, versus none, had higher body mass index (1.18, 95% confidence interval (CI) 0.95 to 1.42 kg/m²), waist circumference (2.80, 95% CI 2.18–3.41 cm), waist-to-hip ratio (0.010, 95% CI 0.006 to 0.015), systolic blood pressure (2.44, 95% CI 0.92 to 3.97 mmHg), diastolic blood pressure (1.94, 95% CI 1.14 to 2.73 mmHg), FPG (0.310, 95% CI 0.188 to 0.432 mmol/L), triglycerides (0.185, 95% CI 0.096 to 0.273 mmol/L), and lower high-`density lipoprotein cholesterol (− 0.040, 95% CI − 0.069 to − 0.012 mmol/L). Similar results were found for the associations of spicy foods strength with CVD risk factors. The results attenuated slightly but not substantially across diabetes groups.

Conclusions

Our study showed that higher frequency and strength of spicy foods intake were associated with unfavorable cardiovascular disease risk profile in older people, and such associations did not vary by diabetes status. Whether the results were causal needs to be determined in further studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13697-6.

Aortic arch calcification and risk of all-cause mortality and cardiovascular disease: The Guangzhou Biobank Cohort Study

Background

There were no reports on the associations of aortic arch calcification (AAC) measured by chest X-ray with all-cause mortality and cardiovascular disease (CVD) in older general population. Moreover, previous studies of hemodialysis patients showed that AAC was correlated with left ventricular hypertrophy (LVH) and predicted CVD jointly. Whether the effects remained in the general population is unknown. We examined the associations of AAC with all-cause mortality and CVD in general population and the risk associated with the coexistence of AAC and LVH.

Methods

Presence and severity (grades 0-2) of AAC were measured by chest X-ray, and LVH was identified by 12-lead electrocardiogram in 27,166 Chinese aged 50+ years free of CVD from Guangzhou Biobank Cohort Study. Multivariate Cox regressions were used to examine associations of AAC and LVH with outcomes.

Findings

During an average follow-up of 14·3 years, 5,350 deaths and 4,012 CVD occurred. Compared to those without AAC at baseline, those with AAC had higher risks of all-cause mortality (HR 1·24, 95% CI 1·17-1·31) and CVD (HR 1·22, 95% CI 1·14-1·30), with dose-response relationship (P ≤ 0·001). Furthermore, those with coexistence of AAC and LVH had higher risks of all-cause mortality (HR 1·72, 95% CI 1·37-2·15) and CVD (HR 1·80, 95% CI 1·40-2·32) than those without AAC and LVH.

Interpretation

As chest X-ray has been performed commonly for health screening and in hospital patients when first admitted, AAC measured by chest X-ray can be further applied to assist cardiovascular risk stratification in the community and clinical settings.

Funding

The Natural Science Foundation of China (No. 81941019).

[Development of a Ranking Tool for Scientificity, Transparency and Applicability of Clinical Practice Guidelines]

Objective: To address the limitations of existing methods and tools for evaluating clinical practice guidelines, we aimed to develop a comprehensive instrument focusing on the three main dimensions of guideline development: scientificity, transparency, applicability. We will use it to rank the guidelines according to the scores. We abbreviated it as STAR, and its reliability, validity and usability were also tested. Methods: A multidisciplinary expert working group was set up, including methodologists, statisticians, journal editors, medical professionals, and others. Scoping review, Delphi methods and hierarchical analysis were used to determine the final checklist of STAR. Results: The new instrument contained 11 domains and 39 items. Intrinsic reliability of each domain was indicated by Cronbach's α coefficient, with a average value of 0.646. The Cohen's kappa coefficients for methodological evaluators and clinical evaluators were 0.783 and 0.618. The overall content validity index was 0.905. The R2 for the criterion validity analysis was 0.76. The average score for usability of the items was 4.6, and the mean time spent to evaluate each guideline was 20 minutes. Conclusion: The instrument has good reliability, validity and evaluating efficiency, and can be used for evaluating and ranking guidelines more comprehensively.

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 Bayesian network model of new-onset diabetes in older Chinese: The Guangzhou biobank cohort study

BACKGROUND

Existing diabetes risk prediction models based on regression were limited in dealing with collinearity and complex interactions. Bayesian network (BN) model that considers interactions may provide additional information to predict risk and infer causation.

METHODS

BN model was constructed for new-onset diabetes using prospective data of 15,934 participants without diabetes at baseline [73% women; mean (standard deviation) age = 61.0 (6.9) years]. Participants were randomly assigned to a training (n = 12,748) set and a validation (n = 3,186) set. Model performances were assessed using area under the receiver operating characteristic curve (AUC).

RESULTS

During an average follow-up of 4.1 (interquartile range = 3.3-4.5) years, 1,302 (8.17%) participants developed diabetes. The constructed BN model showed the associations (direct, indirect, or no) among 24 risk factors, and only hypertension, impaired fasting glucose (IFG; fasting glucose of 5.6-6.9 mmol/L), and greater waist circumference (WC) were directly associated with new-onset diabetes. The risk prediction model showed that the post-test probability of developing diabetes in participants with hypertension, IFG, and greater WC was 27.5%, with AUC of 0.746 [95% confidence interval CI) = 0.732-0.760], sensitivity of 0.727 (95% CI = 0.703-0.752), and specificity of 0.660 (95% CI = 0.652-0.667). This prediction model appeared to perform better than a logistic regression model using the same three predictors (AUC = 0.734, 95% CI = 0.703-0.764, sensitivity = 0.604, and specificity = 0.745).

CONCLUSIONS

We have first reported a BN model in predicting new-onset diabetes with the smallest number of factors among existing models in the literature. BN yielded a more comprehensive figure showing graphically the inter-relations for multiple factors with diabetes than existing regression models.

Association of a composite score of relative grip strength and timed up and go test with incident type 2 diabetes mellitus: Guangzhou Biobank Cohort Study

Background: We investigated association of a score incorporating relative grip strength (RGS) and timed up and go (TUG) test with incident type 2 diabetes mellitus (T2DM) in older Chinese.

Methods: Both RGS and TUG scores were classified into tertiles (0~2 points) and summed to yield RGS-TUG score, ranging from 0 to 4 points, with higher points indicating better physical function. Cox proportional hazards regression was used to analyze association of RGS-TUG score with incident T2DM.

Results: 3,892 participants without T2DM were followed up for an average of 3.6 years with 240 developing T2DM. After adjustment, those with the lowest RGS-TUG score, versus the highest, had higher fasting glucose, two-hour post-load glucose and glycosylated hemoglobin A1c, with β (95% confidence interval (CI)) being 0.21 (0.08, 0.33), 1.06 (0.69, 1.43) and 0.16 (0.06, 0.27), respectively. In participants with BMI of ≥25 kg/m2, those with the lowest RGS-TUG score showed a higher risk of T2DM (adjusted hazard ratio 3.01, 95% CI 1.04–8.69). No association was found for BMI of 18.5~<25 kg/m2 (P for interaction < 0.05).

Conclusions: This is the first study showing lower RGS-TUG score was associated with increased glycemia and incident T2DM in older people with overweight/obesity. The underlying mechanisms warrant further investigation.

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 β 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.

METHODS

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.

Glycemic Measures and Risk of Mortality in Older Chinese: The Guangzhou Biobank Cohort Study

CONTEXT

China has the largest number of people with type 2 diabetes mellitus (T2DM) in the world. Data from previous studies have suggested that up to one-fifth of individuals with diabetes would be missed without an oral glucose tolerance test (OGTT). To date, there is little information on the mortality risk of these individuals.

OBJECTIVE

We estimated the association of different indicators of hyperglycemia with mortality in the general Chinese population.

DESIGN

Prospective cohort study.

SETTING

China.

PARTICIPANTS

A total of 17 939 participants aged 50+ years.

EXPOSURES

Previously diagnosed diabetes and newly detected diabetes defined by fasting glucose (≥7.0 mmol/L), 2-hour postload glucose (≥11.1 mmol/L), or hemoglobin A1c (HbA1c, ≥6.5%).

MAIN OUTCOMES MEASURES

Deaths from all-cause, cardiovascular disease, and cancer were identified by record linkage with death registration.

RESULTS

During 7.8 (SD, 1.5) years' follow-up, 1439 deaths were recorded. Of 3706 participants with T2DM, 2126 (57%) had known T2DM, 118 (3%) were identified by isolated elevated fasting glucose, 1022 (28%) had isolated elevated postload glucose, and 440 (12%) had both elevated fasting and postload glucose. Compared with normoglycemia, the hazard ratio (95% confidence interval) of all-cause mortality was 1.71 (1.46-2.00), 0.96 (0.47-1.93), 1.43 (1.15-1.78), and 1.82 (1.35-2.45) for the 4 groups, respectively. T2DM defined by elevated HbA1c was not significantly associated with all-cause mortality (hazard ratio, 1.17; 95% confidence interval, 0.81-1.69).

CONCLUSION

Individuals with isolated higher 2-h postload glucose had a higher risk of mortality by 43% than those with normoglycemia. Underuse of OGTT leads to substantial underdetection of individuals with a higher mortality risk and lost opportunities for early intervention.

The mediating role of inflammation in the association between cigarette smoking and intima-media thickness: The Guangzhou biobank cohort study

Cigarette smoking is associated with thicker carotid intima-media thickness (IMT), probably partly through inflammatory pathways. However, to what extent does inflammation mediate the smoking-carotid atherosclerosis association is unclear. We investigated the mediating effect of inflammation on the association between cigarette smoking and carotid IMT, and quantified the respective contributions of inflammatory markers to this association.A total of 1752 participants from Guangzhou Biobank Cohort Study-Cardiovascular Disease Sub-cohort (GBCS-CVD) were included. Using causal mediation analysis under the counterfactual framework, we decomposed total effects of cigarette smoking on IMT into indirect effects (through inflammatory response) and direct effects (not through inflammatory response).After adjusting for traditional risk factors, the indirect effects of per 10/L increment in leukocyte and granulocyte, per mg/L increment in high-sensitivity C-reactive protein (hs-CRP), and per mg/dL increment in fibrinogen on carotid IMT was 0.0028 mm (95% confidence interval [CI], 0.0011-0.0047), 0.0019 mm (95% CI, 0.0006-0.0034), 0.0017 mm (95% CI, 0.0006-0.003), and 0.001 mm (95% CI, 0.0001-0.0021), respectively. No evidence for a mediating role of lymphocyte was found. The proportion of the smoking-IMT association mediated by leukocyte, granulocyte, hs-CRP, and fibrinogen was 12.57% (95% CI, 8.50%-22.11%), 8.50% (95% CI, 5.76%-15.09%), 7.64% (95% CI, 5.20%-13.79%), and 4.48% (95% CI, 3.04%-8.03%), respectively. Restricting data analysis to men showed similar results.The effects of cigarette smoking on IMT were partly mediated by leukocyte, hs-CRP, and fibrinogen. The mediating role of leukocyte was likely mainly driven by higher granulocyte.

Sleep quality and cognitive impairment in older Chinese: Guangzhou Biobank Cohort Study

BACKGROUND

evidence concerning the relationship between sleep quality and cognitive impairment is limited and inconsistent.

OBJECTIVE

to examine the association of sleep quality with memory impairment and poor cognitive function in a large sample of older Chinese.

METHODS

15,246 participants aged 50+ years of the Guangzhou Biobank Cohort Study who attended the second physical examination from 2008 to 2012 were included. Sleep quality was assessed using Pittsburgh Sleep Quality Index (PSQI), and cognitive performance was assessed using both Delayed Word Recall Test (DWRT) and Mini-Mental State Examination (MMSE). Memory impairment was defined by DWRT score < 4 and poor cognitive function by MMSE score < 25.

RESULTS

after adjusting for potential confounders, lower habitual sleep efficiency was associated with a higher risk of memory impairment and poor cognitive function with a dose-response pattern (both P for trend <0.001). The adjusted odds ratio (OR, 95% confidence interval (CI)) for poor cognitive function in those with the sleep efficiency of 75-85%, 65-75% and <65%, versus ≥85%, was 1.31 (1.12-1.53), 1.41 (1.16-1.73) and 1.33 (1.09-1.63), respectively. No association of the global PSQI score with memory impairment or poor cognitive function was found.

CONCLUSIONS

in older Chinese people, lower habitual sleep efficiency was associated with a higher risk of memory impairment and poorer cognitive function.

All-cause and cause-specific mortality from restrictive and obstructive spirometric patterns in Chinese adults with and without dyspnea: Guangzhou Biobank Cohort Study

OBJECTIVE

To study whether abnormal spirometric patterns were associated with differential mortality in Chinese adults with and without dyspnea.

METHODS

Guangzhou Biobank Cohort Study (GBCS) participants were classified by spirometric patterns and presence of dyspnea into 6 groups: normal spirometry (NS), restriction on spirometry (ROS) and airflow obstruction (AO), each with and without dyspnea. Adjusted hazard ratios (aHRs) were calculated for mortality using Cox models.

RESULTS

Among 16777 subjects, 1595 (9.5%) had ROS, 1036 (6.2%) had AO and 1009 (6.0%) had dyspnea. A total of 1993 deaths (11.9%) occurred during 11-year follow-up. Using NS without dyspnea as reference, NS with dyspnea was significantly associated with increased cardiovascular mortality risk (aHRs 1.61 (95% confidence interval (CI) 1.18-2.19); ROS with and without dyspnea were associated with increased risks of all-cause (aHRs 1.46 (95% CI 1.28-1.66) and 1.81 (95% CI 1.33-2.47)) and cardiovascular mortality (aHRs 1.89 (95% CI 1.55-2.31) and 1.85 (95% CI 1.12-3.03)), but not of lung cancer mortality (aHRs 1.33 (95% CI 0.91-1.94) and 1.35 (95% CI 0.49-3.70)); AO with and without dyspnea were associated with increased risks of all-cause (aHRs 1.59 (95% CI 1.36-1.86) and 2.36 (95% CI 1.77-3.15)), cardiovascular (aHRs 1.43 (95% CI 1.08-1.90) and 1.61 (95% CI 0.91-2.82)) and lung cancer mortality (aHRs 1.91 (95% CI 1.29-2.84) and 3.01 (95% CI 1.46-6.23)). These associations did not vary by sex or smoking status (all P-values for interaction >0.05).

CONCLUSION

Both ROS and AO, with and without dyspnea, were associated with increased all-cause and cardiovascular disease mortality. The increased risk of all-cause was greater and that of cardiovascular mortality was lower for AO than ROS. AO showed significantly increased risk of lung cancer but ROS did not. (272 words).

[Risk factors and sonographic findings associated with the type of placenta accreta spectrum disorders]

Objective: To evaluate the risk factors and sonographic findings of pregnancies complicated by placenta increta or placenta percreta. Methods: Totally, 2 219 cases were retrospectively analyzed from 20 tertiary hospitals in China from January 2011 to December 2015. The data were collected based on the original case records. All cases were divided into two groups, the placenta increta (PI) group (79.1%, 1 755/2 219) and the placenta percreta (PP) group (20.9%, 464/2 219) , according to the degree of placental implantation. The risk factors and sonographic findings of placenta increta or percreta were analyzed by uni-factor and logistic regression statistic methods. Results: The risk factors associated with the degree of placental implantation were age, gravida, previous abortion or miscarriage, previous cesarean sections, and placenta previa (all P<0.05), especially, previous cesarean sections (χ(2)=157.961) and placenta previa (χ(2)=91.759). Sonographic findings could be used to predict the degree of placental invasion especially the boundaries between placenta and uterine serosa, the boundary between placenta and myometrium, the disruption of the placental-uterine wall interface and loss of the normal retroplacental hypoechoic zone(all P<0.01). Conclusions: Previous cesarean sections and placenta previa are the main independent risk factors associated with the degree of placenta implantation. Ultrasound could be used to make a prenatal suggestive diagnosis of placenta accreta spectrum disorders.

White blood cell count and all-cause and cause-specific mortality in the Guangzhou biobank cohort study

Background

Several studies have shown positive associations between higher WBC count and deaths from all-causes, CHD, stroke and cancer among occidental populations or developed countries of Asia. No study on the association of WBC count with all-cause and cause-specific mortality in Chinese populations was reported. We studied this using prospective data from a large Chinese cohort.

Methods

We used prospective data from the Guangzhou Biobank Cohort Study (GBCS), a total of 29,925 participants in present study. A Cox proportional hazards regression model was used to estimate the hazard ratios (HR) and 95% confidence interval (CI).

Results

The hazard ratios (HR) for all-cause, CHD, and respiratory disease mortality for the highest decile of WBC count (women > 8.2 × 10⁹/L; men > 8.8 × 10⁹/L) was 1.83 (95% confidence interval (CI) 1.54, 2.17), 3.02 (95% CI 1.84, 4.98) and 2.52 (95% CI 1.49, 4.27), respectively, after adjusting for multiple potential confounders. The associations were similar when deaths during the first 2 years of follow-up were excluded. After further adjusting for pulmonary function, the highest decile of WBC count was associated with 90% higher risk of respiratory disease mortality (HR 1.90, 95% CI 1.08, 3.33). No evidence for an association between higher WBC count and cancer mortality was found. Sub-type analysis showed that only granulocyte count remained significantly predictive of all-cause, CHD, and respiratory disease mortality.

Conclusions

Elevated WBC, specifically granulocyte, count was associated with all-cause, CHD and respiratory mortality in southern Chinese. Further investigation is warranted to clarify whether decreasing inflammation would attenuate WBC count associated mortality.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-6073-6) contains supplementary material, which is available to authorized users.

[Mediating effect of hemoglobin and hematocrit on the association between alcohol consumption and blood pressure among middle-aged and elderly male residents in Guangzhou]

Objective: To explore the mediating effect of hemoglobin (Hb) and hematocrit (HCT) on the association between alcohol consumption and blood pressure, and provide evidence for the prevention and control of alcohol-attributed hypertension. Methods: 1 091 male (age >50 years old) participants with drinking habit were selected from the Guangzhou biobank cohort study (GBCS). Mediation analysis was used to evaluate the mediating effect of Hb and HCT on the association of alcohol consumption (unit/day) with systolic blood pressure (SBP), diastolic blood pressure(DBP), pulse pressure(PP) and mean arterial pressure (MAP). Results: After adjusting for age, body mass index, education level, personal annual income, smoking, occupation and physical activity, the associations of alcohol consumption with SBP, DBP, PP and MAP were partly mediated by Hb, the proportion of mediating effect was 11.8% (95%CI 4.8%-24.7%), 15.3% (95%CI 6.5%-32.0%), 8.4% (95%CI 2.2%-22.5%) and 13.5% (95%CI 5.9%-27.5%), respectively. The associations of alcohol consumption with SBP, DBP, and MAP were also partly mediated by HCT, the proportion of mediating effect was 6.3% (95%CI 1.0%-16.0%), 8.7% (95%CI 1.4%-21.4%), and 7.5% (95%CI 1.0%-18.6%), respectively. Conclusion: There is a significant mediating effect of Hb and HCT on the association between alcohol consumption and blood pressure. Besides efforts on alcohol control, the potential effects of alcohol-induced increase on Hb and HCT, which might also increase the blood pressure, need to be considered to achieve optimal monitoring and prevention of alcohol-related hypertension.

Relationship between pulmonary function and peripheral vascular function in older Chinese: Guangzhou biobank cohort study-CVD

BACKGROUND

Findings describing the relationship between pulmonary function and peripheral vascular function have been inconclusive. We explored this relationship in Guangzhou Biobank Cohort Study-Cardiovascular Subcohort (GBCS-CVD).

METHODS

Brachial-ankle pulse wave velocity (baPWV) and ankle brachial index (ABI) were measured by a waveform analyser, and pulmonary function by turbine flowmeter spirometry. Predicted forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were derived using equations for Chinese. Regression analyses were used to investigate the association.

RESULTS

Of 1528 older Chinese, 980 (64.1%) had arterial stiffness (baPWV ≥1400 cm/s), but only 29 (1.9%) had peripheral arterial disease (PAD) (ABI < 0.9). The mean (±standard deviation, SD) baPWV was 1547 (±298) cm/s and mean (±SD) ABI 1.09 (±0.09). Before and after adjusting for potential confounders, baPWV was negatively associated with FEV1 and FVC % predicted (% predicted = observed/predicted × 100%) (adjusted β: - 0.95 and - 1.16 respectively, p < 0.05), and ABI was marginally non-significantly positively associated with FEV1% predicted (adjusted β 0.02, p = 0.32) and FVC% predicted (adjusted β 0.02, p = 0.18). Compared to participants in the highest tertile of pulmonary function, those in the lowest had higher risk of arterial stiffness (adjusted odds ratio (AOR) 1.51, 95% CI 1.09-2.10 for FEV1 and AOR 1.69, 95% CI 1.22-2.33 for FVC), but the higher risk of PAD was marginally non-significant (AOR 1.64, p = 0.42 for FEV1 and AOR 1.65, p = 0.24 for FVC).

CONCLUSION

In older relatively healthy normal weight Chinese, pulmonary function was inversely dose-dependently associated with arterial stiffness, while the association with PAD was much weaker.

Experimental Evidence of Kinetic Effects in Indirect-Drive Inertial Confinement Fusion Hohlraums

We present the first experimental evidence supported by simulations of kinetic effects launched in the interpenetration layer between the laser-driven hohlraum plasma bubbles and the corona plasma of the compressed pellet at the Shenguang-III prototype laser facility. Solid plastic capsules were coated with carbon-deuterium layers; as the implosion neutron yield is quenched, DD fusion yield from the corona plasma provides a direct measure of the kinetic effects inside the hohlraum. An anomalous large energy spread of the DD neutron signal (∼282  keV) and anomalous scaling of the neutron yield with the thickness of the carbon-deuterium layers cannot be explained by the hydrodynamic mechanisms. Instead, these results can be attributed to kinetic shocks that arise in the hohlraum-wall-ablator interpenetration region, which result in efficient acceleration of the deuterons (∼28.8  J, 0.45% of the total input laser energy). These studies provide novel insight into the interactions and dynamics of a vacuum hohlraum and near-vacuum hohlraum.

High relative risk of all-cause mortality attributed to smoking in China: Guangzhou Biobank Cohort Study

BACKGROUND

Prediction of disease burden in China arising from smoking based on earlier cohorts in the West and China could not reflect the disease burden at the current stage accurately. No cohort studies in China focused specifically on people born since 1950. We examined the risk of all-cause mortality attributed to smoking in adults in Guangzhou, the city with the most rapidly expanding economy in China.

METHODS AND FINDINGS

This population-based prospective cohort included 21,658 women and 8,284 men aged 50+ years enrolled from 2003-2008 and followed until January 2016. During an average follow-up of 8.8 (standard deviation = 1.8) years, 2,986 (1,586 women, 1,400 men) deaths were recorded. After adjustment for confounders, the hazards ratios (95% confidence interval (CI)) of all-cause mortality in current versus never smokers increased from 1.61 (95% CI 1.45-1.80) in those born in 1920-1939 to 2.02 (95% CI 1.74-2.34), and 4.40 (95% CI 3.14-6.17), in those born in the 1940s and 1950s, respectively (P for trend 0.009).

CONCLUSIONS

In smokers born after 1949 in Guangzhou and other areas which have the longest history of smoking, the mortality risk could have reached three fold that of non-smokers, as in the UK, US and Australia. If confirmed, unless China quickly and strictly complies with the WHO Framework Convention on Tobacco Control with massive smoking cessation in the population, this is a more striking warning that China will be facing an even larger disease burden from tobacco use than previous forecasts.

[Association between body weight change during early and middle adulthood and the risk of type 2 diabetes in middle aged and elderly population]

Objective: To examine the association between weight changes during early and middle adulthood and the risk of type 2 diabetes mellitus in middle aged and elderly population. Methods: Based on the Guangzhou Biobank Cohort Study (GBCS), 28 736 residents aged ≥50 years were included in Guangzhou. Multivariate logistic regression was used to analyze the association between body weight changes during early or middle adulthood and age when the heaviest weight reaching the threshold on the risk of type 2 diabetes mellitus in middle age or elderly population. Adjustments on age, smoking, alcohol consumption, physical activity, education level, occupation, district of residence and body mass index etc., were made. Results: The mean age was 64.3 (standard deviation=6.7) years in men and 61.0 (standard deviation=7.0) years in women, with the prevalence rates of diabetes as 13.1% and 13.7% in men and women, respectively. Compared to those with stable body weight, the risk of diabetes increased with weight gain during early and middle adulthood in both men and women (both P values for trend<0.01). Participants who gained more than 20 kg during early and middle adulthood were associated with the highest risk of diabetes in men (OR=2.83, 95%CI:1.99-4.02) and women (OR=3.13, 95%CI: 2.47-3.96). Compared to those who reached the highest weight at age 20, those who reaching the highest weight at 40 to 49 years were associated with the highest risk of diabetes, with OR being 5.32 (95%CI: 1.92-14.8) in men and 3.41 (95%CI: 2.49-4.67) in women, respectively. Weight loss in adulthood was associated with self-reported but not newly diagnosed diabetic cases in both middle and older aged men and women. Conclusion: Weight gain during early and middle adulthood may increase the risk of diabetes in middle and older aged population. The detrimental effect of obesity on diabetes might become significantly visible in the next decades.

Association of adiposity with pulmonary function in older Chinese: Guangzhou Biobank Cohort Study

OBJECTIVE

We examined the association between different adiposity indices and pulmonary function in Chinese adults in the Guangzhou Biobank Cohort Study (GBCS).

METHODS

Participants with body mass index (BMI) < 18.5 (underweight) were excluded. Adiposity indices including BMI, waist circumference (WC), waist hip ratio, waist height ratio and body fat percentage were measured. Lung function was assessed by spirometry using a turbine flowmeter. We analyzed percent predicted for forced expiratory volume in 1 s (FEV₁%), forced vital capacity (FVC %) and restrictive respiratory defect (FEV₁/FVC ratio > low limits of normal and FVC % <0.80).

RESULTS

Of 16186 participants (mean age 61.4 ± 7.2 years; 74.0% women), 116 (0.7%) had only general obesity (BMI ≥28 kg/m²), 4079 (25.2%) had only central obesity (WC: ≥90 cm in men, ≥80 cm in women) and 1591 (9.8%) had both central obesity and general obesity. Comparing to those with neither central nor general obesity, those with only central adiposity and with both central and general obesity had lower pulmonary function (adjusted β range from -2.85 to -6.02 for FEV₁% and FVC%, adjusted OR range from 1.14 to 1.70, all P < 0.05). But those with only general obesity had better but non-significant pulmonary function. (Crude β range from 1.46 to 2.92 for FEV₁% and FVC%, crude OR range from 0.68 to 0.93, all P > 0.05). Both FEV₁% and FVC% decreased per standard deviation increase in obesity indices (adjusted β from -0.46 to -3.17, all P < 0.002). A positive association of central or general obesity with restrictive respiratory defect was observed (adjusted odds ratio (AOR) from 1.50 to 2.04, all P < 0.002). Further adjustment for WC reversed the inverse association between BMI and pulmonary function (adjusted β from 1.93 to 6.22, all P < 0.001) and restrictive respiratory defect (adjusted AOR from 0.72 to 0.80, all P < 0.001).

CONCLUSION

Central adiposity and its indices, but not general adiposity and BMI, were independently associated with lower pulmonary function and higher risk of restrictive respiratory defect in older Chinese.

Adiposity and incident diabetes within 4 years of follow-up: the Guangzhou Biobank Cohort Study

AIM

Whether different adiposity measures predict incident diabetes differentially in general Chinese populations is unclear. We investigated this in Chinese people aged 50+ years in the Guangzhou Biobank Cohort Study.

METHODS

Waist circumference and BMI were measured at baseline, and fasting glucose was measured at both baseline and follow-up examinations. Incident diabetes was defined as fasting glucose ≥ 7.0 mmol/l, glucose after 2-h oral glucose tolerance test ≥ 11.1 mmol/l, and/or self-reported physician-diagnosed diabetes during the follow-up period.

RESULTS

Of 15 752 people without diabetes at baseline from 2003 to 2008, 1779 (11.3%) developed incident diabetes during the follow-up from 2008 to 2012 (mean = 3.6 years, sd = 1.0). After mutually adjusting each other and adjusting for other potential confounders, waist circumference showed a higher predictive value than BMI. The odds ratio (OR) (95% confidence interval (CI) was 1.50 (95% CI 1.37-1.64) for a 1 sd increment in waist circumference and 1.21 (95% CI 1.11-1.33), for a 1 sd increment in BMI. Similarly, after mutual adjustment, abdominal obesity was associated with an almost twofold odds of incident diabetes (OR 1.93, 95% CI 1.71-2.17), which was higher than that for general obesity (OR 1.76, 95% CI 1.50-2.06). The area under receiver operating characteristic curve (AUC) for waist circumference was higher than that for BMI [AUC = 0.676 (95% CI 0.660-0.686) vs. 0.665 (95% CI 0.651-0.678), P = 0.02].

CONCLUSION

Abdominal obesity predicted incident diabetes in older people better than general obesity. Our findings may be an early warning signal for local government or public health practitioners to develop and investigate more effective intervention programmes for diabetes, and should also be disseminated to the public to pay more attention to this important public health issue.

Mendelian randomization estimates of alanine aminotransferase with cardiovascular disease: Guangzhou Biobank Cohort study

Observational studies of the association of alanine aminotransferase (ALT) levels with ischaemic heart disease (IHD) and cardiovascular disease (CVD) risk factors are inconsistent, probably because of confounding and reverse causality. Mendelian randomization (MR) provides less confounded results. We used MR analysis to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors. We used instrumental variable analysis based on two single nucleotide polymorphism (SNPs) HSD17B13/MAPK10 (rs6834314) and PNPLA3/SAMM50 (rs738409) to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors in the Guangzhou Biobank Cohort Study (GBCS). Observationally in 19,925 participants ALT levels were strongly positively associated with self-reported IHD, systolic and diastolic blood pressure, low-density lipoprotein- and total cholesterol, triglycerides, fasting glucose, body mass index, waist circumference, heart rate (HR) and diabetes, but were not associated with uncorrected QT interval, HR-corrected QT interval or high-density lipoprotein-cholesterol. In the MR study, using a credible genetic instrument (F-statistic = 23) for ALT, ALT levels were negatively associated with IHD (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.87 to 0.97) and triglycerides (β - 0.08, 95% CI - 0.13 to - 0.03), but were not associated with other CVD risk factors. Our results using Mendelian randomization suggest that ALT reduces the risk of IHD, probably through reducing triglyceride levels. The underlying mechanisms deserve further investigation.

[Correlation between body fat percentage and general obesity indexes in middle aged and old people in Guangzhou]

Objective: To examine the correlation between body fat percentage (BFP) and general obesity indexes, including body mass index (BMI), waist circumference (WC) and waist to hip ratio (WHR) and calculate the corresponding BFP cutoff values in the middle aged and old people in Guangzhou. The corresponding cut-point of optimal body fat percentage for Guangzhou older population. Methods: Based on the Guangzhou Biobank Cohort Study (GBCS), 3 490 relatively healthy Guangzhou residents aged ≥50 years were selected and were randomly divided into 2 groups. The equations between BFP and BMI, WC, WHR were set up with Curve fitting analysis in one group. The multiple regression analysis was undertaken to establish predictive equations between BFP and BMI, WC, WHR with stepwise model for adding gender, age, physical activity, drinking and smoking. Then, the optimal cut-points of BFP corresponding to BMI, WC and WHR to reflect the degree of obesity were calculated. The equations were then validated with another group. Results: BFP increased with the increase of WHR, WC and BMI. BMI was a better predictor of body fat percentage than WC and WHR. The final regression equation was BFP=(-23.47 -8.87×sex) +2.94× (BMI) - 0.024 × (BMI)²,the coefficient of determination was 0.805. Based on the equation, the BFP corresponding to overweight/obesity (24 kg/m²≤BMI<28 kg/m²) were 24.3% ≤BFP<31.1% in men and 33.2%≤BFP<40.0% in women, respectively. BMI had a better consistency with BFP in identify obesity compared with WC and WHR, obtained the area of ROC 0.909 in men and 0.919 in women respectively. The sensitivity and specificity were 70.3% and 85.5% in men; and 75.2% and 93.0% in women respectively. Conclusion: BFP has a better correlation with BMI. The study results indicated that BFP for middle aged and old males and females in Guangzhou corresponding to overweight/obesity (BMI≥24 kg/m²) were <24.0% and <33.0% respectively.

Changes in adiposity in an older Chinese population in rapid economic transition

OBJECTIVE

To examine the changes in body mass index (BMI) and waist circumference (WC) in Guangzhou, South China, which is probably experiencing the most rapid economic transition in history.

METHODS

In this study, 17,786 Chinese aged 50+ years were recruited from 2003 to 2008 and followed up until 2012. BMI and WC were measured at two time points.

RESULTS

During the mean follow-up of 3.6 years (median = 3, interquartile = 1), age-adjusted mean BMI increased only slightly. By contrast, mean WC increased sharply by 0.94 cm (95% confidence interval 0.93-0.94) annually in men and 1.29 cm (1.28-1.29) annually in women. In 77% of women and 69% of men, WC increased, and among them, the mean annual increase was 2.01 cm and 1.70 cm, respectively. Among healthy, never-smoking participants, the incidence of central obesity was 29.0% (36.4% in women and 14.2% in men). The incidence of general obesity was 1.9% and was similarly low in both men and women (2.1% vs. 1.8%). Conversely, 20.3% of individuals with general obesity became nonobese, and 12.8% of individuals with central obesity returned to normal.

CONCLUSIONS

Central obesity has risen sharply in this cohort. Such increases may have been greatly underestimated previously and should form the basis of an even stronger warning for regions undergoing economic transitions in China and elsewhere.