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• Due to rapid urbanization and despite numerous physical activity (PA) promotion programs, PA levels in China have been continuously decreasing. However, it remains unclear whether increasing or decreasing PA is beneficial for middle-aged and older Chinese. • Maintaining high levels of PA and increasing PA from low levels to high levels lowers mortality risks for those at an older age, suggesting that substantial health benefits might be achieved by consistently maintaining or increasing engagement in PA. • The increased mortality risk brought on by maintaining PA at a low level or decreasing it to a low level warrants the attention of public health officials and clinicians. Physical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population. Hence, we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks. Metabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated. Participants were divided into 3 groups related to PA level, and changes in PA were classified into 9 categories. Information on vital status and causes of death from March 2008 to December 2012 (the first repeated examination) until December 31, 2017, was obtained via record linkage with the Death Registry. Of 18,104 participants aged 61.21 ± 6.85 years (mean ± SD), 1461 deaths occurred within 141,417 person-years. Compared to participants who maintained moderate PA, those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality (hazard ratio (HR) = 1.47, 95% confidence interval (95%CI): 1.11–1.96). Participants who maintained a high level of PA (HR = 0.83, 95%CI: 0.70–0.98) or increased PA from low to high levels (HR = 0.71, 95%CI: 0.52–0.97) showed lower all-cause mortality risks. Those who maintained low PA levels showed a higher all-cause mortality risk, whereas those who increased their PA levels showed a non-significantly lower risk. Similar results were found for cardiovascular disease risk. Even at an older age, maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks, suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA. The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians. [Display omitted] [ABSTRACT FROM AUTHOR]

To clarify the causal role of age at menarche in depressive symptoms we conducted a Mendelian randomization study using a large Southern Chinese cohort ( n = 12,233). A genetic allele score was derived using stepwise regression with cross validation. Older age at menarche was not associated with geriatric depression scale score. Our findings suggest that higher rates of depression in women are likely attributable to other factors which require investigation. [ABSTRACT FROM AUTHOR]

Objective: The role of estrogen in cognitive function and depressive symptoms is controversial due to discrepancies between results from randomized controlled trials (RCT) and observational studies. Mendelian randomization analysis may provide further insights concerning the role of estrogen in these outcomes as it assesses the effect of lifelong endogenous exposure but is less vulnerable to confounding than observational studies.Method: We used separate sample instrumental variable analysis to estimate the association of log 17β estradiol with cognitive function (Delayed 10 word recall, and Mini Mental State Examination (MMSE)) and depressive symptoms (Geriatric Depression Scale (GDS)) in older Chinese women of the Guangzhou Biobank Cohort Study (GBCS, n=3086). The estimate was derived based on the Wald estimator, the ratio of the association of genetic determinants (rs1008805 and rs2175898) of log 17β-estradiol with cognitive function and depressive symptoms in GBCS and the association of log 17β-estradiol with genetic determinants in the sample of young women in Hong Kong (n=236).Results: Genetically predicted 17β-estradiol was not associated with delayed 10-word recall (0.42 words per log increase in 17β-estradiol (pmol/L), 95% confidence interval (CI) -0.49 to 1.34) MMSE (0.39 per log increase in 17β-estradiol (pmol/L), 95% CI -0.87 to 1.65) or GDS (0.24 per log increase in 17β-estradiol (pmol/L), 95% CI -0.57 to 1.05).Conclusion: These results were largely consistent with evidence from RCTs and did not show any beneficial effect of estrogen on cognitive function and depressive symptoms. However, larger Mendelian randomization analyses are needed to identify any minor effects. [ABSTRACT FROM AUTHOR]

Purpose In Asia, moderate alcohol users have better lung function. Never users have more inactive aldehyde dehydrogenase 2 (ALDH2) alleles (A) potentially generating confounding because inactive alleles may increase acetaldehyde exposure and reduce lung function. Methods We examined the association of ALDH2 genotypes with percentage predicted lung function (forced expiratory volume in 1 second; forced vital capacity) for age, sex, and height among 5641 older Chinese using multivariable linear regression. Results ALDH2 genotypes were associated with alcohol use and height but not other attributes. Inactive alleles were inversely associated with lung function (percentage predicted forced expiratory volume in 1 second −1.52%, 95% confidence interval [CI], −2.52% to −0.51% for one inactive allele and −2.05%, 95% CI, −3.85% to −0.26% for two inactive alleles compared with two active alleles; and for percentage predicted forced vital capacity −1.25%, 95% CI −2.15% to −0.35% and −1.65%, 95% CI, −3.25% to −0.04%). The association of moderate use with lung function was attenuated after adjusting for ALDH2, in addition to other potential confounders. Conclusions Previous findings in Chinese may be confounded by ALDH2. High frequency of inactive ALDH2 alleles in East Asia may exacerbate the effect of environmental acetaldehyde exposure on lung function and potentially on chronic obstructive pulmonary disease. [ABSTRACT FROM AUTHOR]

Background Observationally lower testosterone is associated with an unhealthier cardiovascular (CVD) risk profile, but this association is open to confounding and reverse causality. The authors examined the association of testosterone with well-established cardiovascular disease (CVD) risk factors (blood pressure, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL)cholesterol and fasting glucose) and the Framingham score using a Mendelian randomization analysis with a separate-sample instrumental variable estimator.Methods To minimize reverse causality, a genetic score predicting testosterone was developed in 289 young Chinese men from Hong Kong, based on three selected testosterone-related single nucleotide polymorphisms (rs10046, rs1008805 and rs1256031). Multivariable censored and linear regressions were used to examine the association of genetically predicted testosterone levels with CVD risk factors and Framingham score among 4212 older Chinese men from the Guangzhou Biobank Cohort Study.Results Predicted testosterone was unrelated to systolic blood pressure [−0.11 mmHg, 95% confidence interval (CI) −0.70 to 0.48], diastolic blood pressure (0.04 mmHg, 95% CI −0.27 to 0.36), fasting glucose (0.02 mmol/l, 95% CI −0.02 to 0.06) or Framingham score (0.02, 95% CI −0.0001 to 0.03) but associated with higher LDL-cholesterol (0.02 mmol/l, 95% CI 0.01 to 0.04) and lower HDL-cholesterol (−0.01 mmol/l, 95% CI −0.02 to −0.001), after adjustment for potential confounders (age, education, smoking status, use of alcohol and body mass index).Conclusions Our findings did not corroborate observed protective effects of testosterone on cardiovascular risk factors or risk of ischaemic heart disease among men, but raises the possibility that higher testosterone may be associated with an unhealthier lipid profile. [ABSTRACT FROM PUBLISHER]

Background: Dairy products consumption is increasingly common globally. Most of the evidence concerning dairy products comes from observational studies in western populations which are inevitably open to confounding. To triangulate the evidence concerning dairy products, we examined the associations of whole cow's milk consumption with cardiovascular risk factors in a non-Western setting with a different pattern of milk consumption and cardiovascular diseases from Western populations. Methods: We used multivariable censored linear or logistic regression to examine cross-sectionally the adjusted associations of whole cow's milk consumption (none (n = 14892), 1–3/week (n = 2689) and 3+/week (n = 2754)) with cardiovascular risk factors in Chinese (≥50 years) in the Guangzhou Biobank Cohort Study. Results: Whole cow's milk consumption was negatively associated with systolic blood pressure (3+/week compared to none −2.56 mmHg, 95% confidence interval (CI) −3.63 to −1.49), diastolic blood pressure (−1.32 mmHg, 95% CI −1.87 to −0.77) and triglycerides (−0.06 mmol/L, 95% CI −0.11 to −0.002), but was positively associated with HDL-cholesterol (0.02 mmol/L,95% CI 0.01 to 0.04) and fasting glucose (0.08 mmol/L, 95% CI 0.01 to 0.16) adjusted for age, sex, phase of study, socio-economic position, lifestyle (smoking, alcohol use and physical activity) and adiposity, but had no obvious association with LDL-cholesterol or the presence of diabetes. Conclusions: Whole cow's milk consumption had heterogeneous associations with cardiovascular risk factors. Higher whole cow's milk consumption was associated with lower levels of specific cardiovascular risk factors which might suggest risk factor specific biological pathways with different relations to blood pressure and lipids than glucose. [ABSTRACT FROM AUTHOR]

Summary: Background: Estrogen has neurotrophic and neuroprotective properties in animal and in vitro studies. Epidemiological studies are inconclusive, but suggest a positive association between endogenous estrogen exposure (measured by reproductive period, the number of years between menarche and menopause) and later life cognitive function. Methods: Structural equation modeling was used in a cross-sectional study of 11,094 naturally postmenopausal multiparous Chinese older (≥50 years) women from the Guangzhou Biobank Cohort Study (phases 2 and 3) to assess the interrelationship of four proxies of higher endogenous estrogen exposure (longer reproductive period, older age of first pregnancy, lower parity and shorter average duration of breast feeding per child) with immediate and the delayed 10-word recall score in phases 2 and 3, and with the mini-mental state examination (MMSE) score in phase 3 (5641 women). Results: Adjusted for age, education, childhood and adulthood socio-economic position and physical activity, longer reproductive period was associated with higher scores (0.02 words per year, 95% confidence interval (CI) 0.008–0.02 for delayed recall and 0.05 MMSE score, 95%CI 0.04–0.07, respectively). Lower parity and shorter average duration of breast-feeding per child were also associated with better cognitive function. Conclusions: In a large cohort of naturally postmenopausal Chinese women proxies of greater endogenous estrogen exposure were associated with better cognitive function. These findings support biological evidence for a cognitively protective role of endogenous estrogen. [ABSTRACT FROM AUTHOR]

Purpose: With economic development, there is an emerging epidemic of diabetes in China despite relatively low levels of obesity. Muscle mass, for which adolescence is a key developmental window, may reduce vulnerability to diabetes. We examined the association of recalled adolescent build with diabetes in a large sample from the developing country setting of southern China. Methods: We used multivariable regression in cross-sectional data (2005–2008), from the Guangzhou Biobank Cohort Study (phases 2 and 3) for 19,524 older (≥50 years) Chinese to examine the adjusted associations of recalled adolescent relative weight (light [n = 6843], average [n = 9529], and heavy [n = 3152]) with clinically measured diabetes. Results: As older adults, heavy adolescents had a lower risk of diabetes (odds ratio = 0.86, 95% confidence interval: 0.75–0.99) than light adolescents adjusted for age, sex, education, smoking, leg length, and seated height. This association was stronger after additional adjustment for waist/hip ratio and body mass index. Conclusions: Poor living conditions during adolescence, resulting in low muscle mass, could contribute to vulnerability to diabetes, which, if confirmed, could be relevant to the emerging epidemic of diabetes in the developing world, as well as to minorities and migrants elsewhere. [ABSTRACT FROM AUTHOR]

Purpose: Women usually report attributes of masculinity as attractive. These are attributes are metabolically expensive. We examined the trade off of a key attribute of masculinity, muscularity, proxied by recalled adolescence build, with lifetime reproductive success in the developing country setting of Southern China. Methods: We used poisson multivariable regression in 19,168 older (≥50 years) Chinese from the Guangzhou Biobank Cohort Study (phases 2 and 3) to examine the sex-stratified, adjusted associations of recalled adolescent relative weight (light (n = 6730), average (n = 9344), and heavy (n = 3094)) with number of offspring. Results: Among men, recalled heavy adolescent weight compared with light was associated with an incident rate ratio for offspring of 1.08 (95% confidence interval [CI] 1.04–1.13) adjusted for age. This estimate was unchanged by adjustment for life course socio-economic position. There was no such association in women. Conclusions: Male physical attractiveness, possibly representing levels of testosterone, was rewarded by lifetime reproductive success, despite potential costs. Socio-economic development may facilitate an inevitable move toward environmentally driven higher levels of testosterone with corresponding public health implications for any conditions or societal attributes driven by testosterone. Further investigation is warranted. [ABSTRACT FROM AUTHOR]

Purpose: Earlier pubertal maturation in women may be associated with better cognition. It is unclear whether or not this also occurs in men. We tested the hypothesis that earlier pubertal development in men was associated with better cognition in later adulthood in a developing Chinese population. Methods: Multivariable linear regression was used in cross-sectional study of 2463 older, Chinese men from the Guangzhou Biobank Cohort Study. Mean pubertal age was calculated as the mean of recalled ages of first nocturnal emission, voice breaking and pubarche. We assessed the association of mean pubertal age with delayed 10-word recall and mini-mental state examination (MMSE) scores. Results: Adjusted for age and education, 1 year earlier mean pubertal age was associated with higher delayed 10-word recall (0.06 [95% confidence interval = 0.02–0.10]) and higher MMSE (0.08 [0.03–0.13]) scores. Additional adjustment for childhood and adulthood socio-economic position, sitting height, and leg length did not change the results. Conclusions: These preliminary findings suggest earlier maturation in men is associated with better cognitive function in later adulthood. Whether pubertal timing is a marker of earlier life exposures or reflects a biological relation between somatrophic and/or gonadotrophic hormones and cognitive development is unclear. [ABSTRACT FROM AUTHOR]

Purpose: Observational studies in Western settings show moderate alcohol use associated with better cognitive function, but they are vulnerable to contextual bias. Evidence from non-Western settings may be useful to verify causality. We examined such association in southern China where alcohol use is low. Methods: We used multivariable linear regression in cross-sectional data from the Guangzhou Biobank Cohort Study to assess sex-stratified associations of alcohol use (never, occasional, moderate, heavy and former drinker) with delayed 10-word recall score for all 3 phases (N = 28,537) and Mini-Mental State Examination (MMSE) score in phase 3 (N = 9,571). Results: Delayed 10-word recall scores were higher in moderate drinkers compared with never drinkers among men (0.30 words, 95% confidence interval [CI]: 0.18 to 0.42) but not women (0.02; 95% CI: –0.12 to 0.17), adjusted for sociodemographic factors. Occasional alcohol users also had higher 10-word recall scores among men (0.27; 95% CI: 0.18 to 0.37) and women (0.30; 95% CI: 0.23 to 0.37). These estimates were little altered by further adjustment for cardiovascular risk factors. Results for MMSE scores were similar. Conclusions: Alcohol may not drive the association between moderate use and better cognitive function, which instead may be due to confounding by general moderation in lifestyle. [ABSTRACT FROM AUTHOR]

Purpose: In randomized controlled trials reducing high hematocrit (Hct) in patients with polycythemia vera protects against cardiovascular disease (CVD) events, whereas increasing Hct in anemia patients causes CVD events. Hct is influenced by environmental and lifestyle factors. Given limited knowledge concerning the drivers of Hct, we took an agnostic approach to identify drivers of Hct.Methods: We used an environment-wide association study to identify environmental and lifestyle factors associated with Hct in 20443 older Chinese adults (mean age = 62.7 years) from the Guangzhou Biobank Cohort Study. We evaluated the role of 25 nutrients, 40 environmental contaminants, two metals (only available for 10405 participants), and six lifestyle factors in relation to Hct, adjusted for sex, age, recruitment phase, and socioeconomic position.Results: In a mutually adjusted model vitamin A, serum calcium, serum magnesium, and alcohol use were associated with higher Hct, whereas physical activity was associated with lower Hct.Conclusions: Despite the difficulty of ascertaining causality, finding both expected (vitamin A and physical inactivity) and novel factors (serum calcium, serum magnesium and alcohol use) strongly associated with Hct illustrates the utility of environment-wide association study to generate hypotheses regarding the potential contribution of modifiable exposures to CVD. [ABSTRACT FROM AUTHOR]

Abstract: Aims: To examine the association between white blood cell count (WBC) and metabolic syndrome (MS) in an older Chinese population. Methods: Three thousand and twenty men and 7256 women aged 50–85 years were recruited and received a medical check-up including measurement of complete blood count, blood pressure, obesity indices, fasting total, LDL-, HDL-cholesterol, triglycerides, glucose and c-reactive protein (CRP). Information on socioeconomic and lifestyle factors was also collected. Results: Vascular risk factors including waist circumference, body mass index, triglyceride, total-, LDL-cholesterol, CRP and systolic and diastolic blood pressures were all positively associated with WBC in both men and women (p from 0.0085 to <0.001). The risk of MS increased significantly with higher total WBC, with adjusted odds ratios (95% confident interval) for second and third tertiles of 1.86 (1.43, 2.42), 2.56 (1.98, 3.32) in men and 1.67 (1.46, 1.90), 2.66 (2.34, 3.03) in women, respectively. Neutrophil and lymphocyte were strongly correlated with total WBC and showed similar association with the MS. Conclusion: There is a strong relationship between total WBC, neutrophil and lymphocyte and the constellation of MS components and associated vascular risk in this older Chinese population. [Copyright &y& Elsevier]