Effects of genetically proxied lipid-lowering drugs on acute myocardial infarction: a drug-target mendelian randomization study.

OBJECTIVE: High low-density-lipoprotein (LDL) cholesterol has been associated with an increased risk of coronary artery diseases (CAD) including acute myocardial infarction (AMI). However, whether lipids lowering drug treatment is causally associated with decreased risk of AMI remains largely unknown. We used Mendelian randomization (MR) to evaluate the influence of genetic variation affecting the function of lipid-lowering drug targets on AMI. METHODS: Single-nucleotide polymorphisms (SNPs) associated with lipids as instruments were extracted from the Global Lipids Genetics Consortium (GLGC). The genome-wide association study (GWAS) data for AMI were obtained from UK Biobank. Two sample MR analysis was used to study the associations between high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG) with AMI (n = 3,927). Genetic variants associated with LDL cholesterol at or near drug target gene were used to mimic drug effects on the AMI events in drug target MR. RESULTS: Genetically predicted higher LDL-C (per one SD increase in LDL-C of 38.67 mg/dL, OR 1.006, 95% CI 1.004-1.007) and TG (per one SD increase in TG of 90.72 mg/dL, 1.004, 1.002-1.006) was associated with increased risk of AMI, but decreased risk for higher HDL-C (per one SD increase in HDL-C of 15.51 mg/dL, 0.997, 0.995-0.999) in univariable MR. Association remained significant for LDL-C, but attenuated toward the null for HDL-C and TG in multivariable MR. Genetically proxied lower LDL-C with genetic variants at or near the PCSK9 region (drug target of evolocumab) and NPC1L1 (drug target of ezetimibe) were associated with decreased risk of AMI (0.997, 0.994-0.999 and 0.986, 0.975-0.998, respectively), whereas genetic variants at HMGCR region (drug target of statin) showed marginal association with AMI (0.995, 0.990-1.000). After excluding drug target-related SNPs, LDL-C related SNPs outside the drug target region remained a causal effect on AMI (0.994, 0.993-0.996). CONCLUSIONS: The findings suggest that genetically predicted LDL-C may play a predominant role in the development of AMI. The drug MR results imply that ezetimibe and evolocumab may decrease the risk of AMI due to their LDL-C lowering effect, and there are other non-drug related lipid lowering pathways that may be causally linked to AMI.

Women's reproductive risk score and healthy lifestyle modification in cardiovascular disease: Findings from the UK Biobank.

BACKGROUND AND AIMS: Reproductive risk factors are associated with increased risk of cardiovascular disease (CVD) in women. However, the combined effects of the composite reproductive risk factors on CVD are unknown. This study was performed to construct a reproductive risk score (RRS) to measure reproductive status, examine the association between RRS and CVD, and explore the modification effect of healthy lifestyle on the association in women in the UK Biobank cohort. METHODS: The RRS was constructed in 74,141 female participants with data about the items derived for the RRS in the UK Biobank. The RRS was derived from 17 baseline variables, all of which indicated women's reproductive health status. We defined four categories of RRS status: low-risk group (score 0-1); low-intermediate group (score 2-3); high-intermediate group (score 4-5); and high-risk group (score 6-13). We also constructed a healthy lifestyle score (HLS) with five related factors, and categorized into unhealthy lifestyle group (score: 0-1), intermediate lifestyle group (score: 2-3) and healthy lifestyle group (score: 4-5). RESULTS: Each point increase in the RRS was associated with a 22 % higher risk of CVD (adjusted hazard ratio (aHR): 1.22; 95 % confidence interval (CI): 1.16 to 1.28), 23 % higher risk of IHD (1.23; 1.17 to 1.31) and 19 % higher risk of stroke (1.19; 1.07 to 1.32). The percentage population-attribution risks (PAR%) were 16 % (95 % CI: 8 to 24) for CVD, 15 % (95 % CI: 6 to 24) for IHD and 18 % (95 % CI: 1 to 33) for stroke. A healthy lifestyle significantly attenuated RRS associations with the incidence of CVD and IHD. The attributable proportions due to additive interaction (p < 0.001) between RRS and HLS were 0.14 (95 % CI: 0.07 to 0.22) for CVD and 0.15 (95 % CI: 0.09 to 0.23) for IHD, respectively. CONCLUSIONS: High RRS was associated with increased risks of CVD, IHD and stroke in female participants in the UK Biobank. The early-stage identification of women with reproductive risk using synthesised indicators and appropriate healthy lifestyle interventions could be useful for the prevention of early CVD and the extension of healthy active life expectancy.

Genetically determined blood pressure, antihypertensive drug classes, and frailty: A Mendelian randomization study.

Observational studies have suggested that the use of antihypertensive drugs was associated with the risk of frailty; however, these findings may be biased by confounding and reverse causality. This study aimed to explore the effect of genetically predicted lifelong lowering blood pressure (BP) through different antihypertensive medications on frailty. One-sample Mendelian randomization (MR) and summary data-based MR (SMR) were applied. We utilized two kinds of genetic instruments to proxy the antihypertensive medications, including genetic variants within or nearby drugs target genes associated with systolic/diastolic BP, and expression level of the corresponding gene. Among 298,618 UK Biobank participants, one-sample MR analysis observed that genetically proxied BB use (relative risk ratios, 0.76; 95% CI, 0.65-0.90; p = 0.001) and CCB use (0.83; 0.72-0.95; p = 0.007), equivalent to a 10-mm Hg reduction in systolic BP, was significantly associated with lower risk of pre-frailty. In addition, although not statistically significant, the effect directions of systolic BP through ACEi variants (0.72; 0.39-1.33; p = 0.296) or thiazides variants (0.74; 0.53-1.03; p = 0.072) on pre-frailty were also protective. Similar results were obtained in analyses for diastolic BP. SMR of expression in artery showed that decreased expression level of KCNH2, a target gene of BBs, was associated with lower frailty index (beta -0.02, p = 2.87 × 10-4). This MR analysis found evidence that the use of BBs and CCBs was potentially associated with reduced frailty risk in the general population, and identified KCNH2 as a promising target for further clinical trials to prevent manifestations of frailty.

Associations of birth weight, plasma metabolome in adulthood and risk of type 2 diabetes.

AIMS: We aimed to examine the longitudinal associations of birth weight with plasma metabolites in adulthood, and further quantify the proportions of the links between birth weight and incident adult type 2 diabetes (T2D) that were mediated by plasma metabolites. MATERIALS AND METHODS: A total of 62,033 participants with complete nuclear magnetic resonance metabolomics and birth weight data from the UK Biobank were included in this study. Linear regression was used to assess the associations between birth weight and metabolites. Cox regression was used to estimate hazard ratios for T2D associated with metabolites. We further performed mediation analyses to estimate the extent to which metabolites might mediate the association between birth weight and T2D risk. RESULTS: Low birth weight was associated with the adverse metabolic responses across multiple metabolic pathways, including lipoprotein subclasses, amino acids, fatty acids (FA), and inflammation. Metabolites associated with higher birth weight tended to be associated with a lower risk of T2D (Pearson correlation coefficient: -0.85). A total of 62 metabolites showed statistically significant mediation effects in the protective association of higher birth weight and T2D risk, including large-sized very low-density lipoprotein particles and triglyceride concentrations as well as saturated, and monounsaturated FA and glycoprotein acetyls. CONCLUSIONS: We identified a range of metabolites that reflect the adult metabolic response to birth weight, some of which might lie on the pathway between birth weight and adult T2D risk.

Joint association and interaction of birth weight and lifestyle with hypertension: A cohort study in UK Biobank.

Low birth weight and unhealthy lifestyle are both associated with an increased risk of hypertension. The authors aimed to assess the joint association and interaction of birth weight and lifestyle with incident hypertension. The authors included 205 522 participants free of hypertension at baseline from UK Biobank. A healthy lifestyle score was constructed using information on body mass index, physical activity, diet, smoking status and alcohol intake. Cox proportional hazard models were used to investigate the impact of birth weight, healthy lifestyle score and their joint effect on hypertension. The authors documented 13 548 (6.59%) incident hypertension cases during a median of 8.6 years of follow-up. The multivariate adjusted hazard ratios and 95% confidence intervals were 1.12 (1.09, 1.15) per kg lower birth weight and 0.76 (0.75, 0.77) per score increment in healthy lifestyle score. Healthy lifestyle reduced the risk of hypertension in any category of different birth weight groups. The preventive effect of healthy lifestyle on hypertension was the most pronounced at lower birth weight with <2500 g and 2500-2999 g, respectively. Addictive interaction between birth weight and healthy lifestyle score was observed with the relative excess risk due to interaction of 0.04 (0.03, 0.05). Our findings emphasized the importance of healthy lifestyle for hypertension prevention, especially among the high-risk population with lower birth weight.

Elevated blood remnant cholesterol and triglycerides are causally related to the risks of cardiometabolic multimorbidity.

The connection between triglyceride-rich lipoproteins and cardiometabolic multimorbidity, characterized by the concurrence of at least two of type 2 diabetes, ischemic heart disease, and stroke, has not been definitively established. We aim to examine the prospective associations between serum remnant cholesterol, triglycerides, and the risks of progression from first cardiometabolic disease to multimorbidity via multistate modeling in the UK Biobank. We also evaluate the causality of these associations via Mendelian randomization using 13 biologically relevant SNPs as the genetic instruments. Here we show that elevated remnant cholesterol and triglycerides are significantly associated with gradually higher risks of cardiometabolic multimorbidity, particularly the progression of ischemic heart disease to the multimorbidity of ischemic heart disease and type 2 diabetes. These results advocate for effective management of remnant cholesterol and triglycerides as a potential strategy in mitigating the risks of cardiometabolic multimorbidity.

Women's reproductive risk and genetic predisposition in type 2 diabetes: A prospective cohort study.

OBJECTIVE: To assess synergistic effects of reproductive factors and gene-reproductive interaction on type 2 diabetes (T2D) risk, also the extent to which the genetic risk of T2D can be affected by reproductive risk. METHODS: 84,254 women with genetic data and reproductive factors were enrolled between 2006 and 2010 in the UK Biobank. The reproductive risk score (RRS) was conducted based on 17 reproductive items, and genetic risk score (GRS) was based on 149 genetic variants. RESULTS: There were 2300 (2.8 %) T2D cases during an average follow-up of 4.49 years. We found a significant increase in T2D risk across RRS categories (Ptrend < 0.001). Compared with low reproductive risk, high-mediate (adjusted hazard ratio [aHR] 1.38, 95 % CI 1.20-1.58) and high (aHR 1.84, 95 % CI 1.54-2.19) reproductive risk could increase the risk of T2D. We further observed a significant additive interaction between reproductive risk and genetic predisposition. In the situation of high genetic predisposition, women with low reproductive risk had lower risk of T2D than those with high reproductive risk (aHR 0.47, 95 % CI 0.30-0.76), with an absolute risk reduction of 2.98 %. CONCLUSIONS: Our novo developed RRS identified high reproductive risk is associated with elevated risk of women's T2D, which can be magnified by gene-reproductive interaction.

Associations of daily sedentary behavior, physical activity, and sleep with irritable bowel syndrome: A prospective analysis of 362,193 participants.

BACKGROUND: Irritable bowel syndrome (IBS) substantially affects quality of life and requires early prevention. This study aimed to elucidate the relationships between IBS and daily behaviors, including sedentary behavior (SB), physical activity (PA), and sleep. In particular, it seeks to identify healthy behaviors to reduce IBS risk, which previous studies have rarely addressed. METHODS: Daily behaviors were retrieved from self-reported data of 362,193 eligible UK Biobank participants. Incident cases were determined by self-report or health care data according to Rome IV criteria. RESULTS: A total of 345,388 participants were IBS-free at baseline, during a median follow-up of 8.45 years, 19,885 incident IBS cases were recorded. When examined individually, SB and shorter (≤7 h/day) or longer (>7 h/day) sleep duration were each positively associated with increased IBS risk, and PA was associated with lower IBS risk. The isotemporal substitution model suggested that replacing SB with other activities could provide further protective effects against IBS risk. Among people sleeping ≤7 h/day, replacing 1 h of SB with equivalent light PA, vigorous PA, or sleep was associated with 8.1% (95% confidence interval (95%CI): 0.901-0.937), 5.8% (95%CI: 0.896-0.991), and 9.2% (95%CI: 0.885-0.932) reduced IBS risk, respectively. For people sleeping >7 h/day, light and vigorous PA were associated with a 4.8% (95%CI: 0.926-0.978) and a 12.0% (95%CI: 0.815-0.949) lower IBS risk, respectively. These benefits were mostly independent of genetic risk for IBS. CONCLUSION: SB and unhealthy sleep duration are risk factors for IBS. A promising way to mitigate IBS risk for individuals sleeping ≤7 h/day and for those sleeping >7 h/day appears to be by replacing SB with adequate sleep or vigorous PA, respectively, regardless of the genetic predisposition of IBS.

Associations of healthy aging index and all-cause and cause-specific mortality: a prospective cohort study of UK Biobank participants.

The healthy aging index (HAI) has been recently developed as a surrogate measure of biological age. However, to what extent the HAI is associated with all-cause and cause-specific mortality and whether this association differs in younger and older adults remains unknown. We aimed to quantify the association between the HAI and mortality in a population of UK adults. In the prospective cohort study, data are obtained from the UK Biobank. Five HAI components (systolic blood pressure, reaction time, cystatin C, serum glucose, forced vital capacity) were scored 0 (healthiest), 1, and 2 (unhealthiest) according to sex-specific tertiles or clinically relevant cut-points and summed to construct the HAI (range 0-10). Cox proportional hazard regression models were used to estimate the associations of the HAI with the risk of all-cause and cause-specific mortality. 387,794 middle-aged and older participants were followed up for a median of 8.9 years (IQR 8.3-9.5). A total of 14,112 all-cause deaths were documented. After adjustments, each 1-point increase in the HAI was related to a higher risk of all-cause mortality (hazards ratio [HR], 1.17; 95%CI, 1.15-1.18). Such association was stronger among adults younger than 60 years (1.19, 1.17-1.21) than that among those 60 years and older (1.15, 1.14-1.17) (P interaction < 0.001). For each unit increment of the HAI, the multivariate-adjusted HRs for risk of death were 1.28 (1.25-1.31) for cardiovascular diseases, 1.09 (1.07-1.10) for cancer, 1.36 (1.29-1.44) for digestive disease, 1.42 (1.35-1.48) for respiratory disease, 1.42 (1.33-1.51) for infectious diseases, and 1.15 (1.09-1.21) for neurodegenerative disease, respectively. Our findings indicate that the HAI is positively associated with all-cause and cause-specific mortality independent of chronological age. Our results further underscore the importance of effective early-life interventions to slow aging and prevent premature death.

Identifying Potential Causal Effects of Telomere Length on Health Outcomes: A Phenome-Wide Investigation and Mendelian Randomization Study.

BACKGROUND: Telomere length has been linked to various health outcomes. To comprehensively investigate the causal effects of telomere length throughout the human disease spectrum, we conducted a phenome-wide Mendelian randomization study (MR-PheWAS) and a systematic review of MR studies. METHODS: We conducted a PheWAS to screen for associations between telomere length and 1 035 phenotypes in the UK Biobank (n = 408 354). The exposure of interest was the genetic risk score (GRS) of telomere length. Observed associations passing multiple testing corrections were assessed for causality by 2-sample MR analysis. A systematic review of MR studies on telomere length was performed to harmonize the published evidence and complement our findings. RESULTS: Of the 1 035 phenotypes tested, PheWAS identified 29 and 78 associations of telomere length GRS at a Bonferroni- and false discovery rate-corrected threshold; 24 and 66 distinct health outcomes were causal in the following principal MR analysis. The replication MR using data from the FinnGen study provided evidence of causal effects of genetically instrumented telomere length on 28 out of 66 outcomes, including decreased risks of 5 diseases in respiratory diseases, digestive diseases, and myocardial infarction, and increased risks of 23 diseases, mainly comprised neoplasms, diseases of the genitourinary system, and essential hypertension. A systematic review of 53 MR studies found evidence to support 16 out of the 66 outcomes. CONCLUSIONS: This large-scale MR-PheWAS identified a wide range of health outcomes that were possibly affected by telomere length, and suggested that susceptibility to telomere length may vary across disease categories.

Polysocial and Polygenic Risk Scores and All-Cause Dementia, Alzheimer's Disease, and Vascular Dementia.

BACKGROUND: To establish a polysocial risk score (PsRS) incorporating various social factors for capturing the dementia risk and investigate the benefits of favorable social conditions across different genetic backgrounds. METHODS: This prospective cohort study comprised 345 439 participants initially free of dementia from the UK Biobank. A total of 10 social factors were summed to create a PsRS. A polygenic risk score (PRS) was constructed based on genome-wide significant variants. RESULTS: During a median follow-up of 12.5 years, we documented 4 595 incident all-cause dementia events including 2 067 Alzheimer's disease (AD) events and 1 028 vascular dementia (VD) events. Each additional PsRS was associated with a 19% increased risk of all-cause dementia (hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.17 to 1.21), a 13% increased risk of AD (1.13; 1.10 to 1.16), and a 24% increased risk of VD (1.24; 1.19 to 1.29). 29% (24% to 33%) of dementia cases, 22% (14% to 29%) of AD cases, and 39% (28% to 48%) of VD cases were associated with a disadvantageous social environment. In addition, among participants at a high genetic risk, the low social risk was linked to a lower incidence rate of all-cause dementia, AD, and VD compared to those who had a high social risk, with reductions of 67.8%, 64.5%, and 84.2%, respectively. CONCLUSIONS: The PsRS could be effectively used in discriminating individuals at high risk of dementia. Around a quarter of dementia events could have a connection with a disadvantageous social environment, especially for those genetically susceptible to dementia.

Associations of reproductive risk score and joint exposure to ambient air pollutants with chronic obstructive pulmonary disease: a cohort study in UK Biobank.

BACKGROUND: Reproductive risk factors and air pollution for developing chronic obstructive pulmonary disease (COPD) have been documented separately. However, the combined effects of overall reproductive risk status on COPD and the extent to which this can be impacted by air pollution are unknown. The aim of this study was to construct a reproductive risk score (RRS) and an air pollution score (APS) and assess independent and joint associations between the two with incident COPD risk. METHODS: 78,027 female participants aged 40-69 years without baseline COPD from UK Biobank recruited between 2006 to 2010 were included in this study. RRS was constructed by 17 women's reproductive health-related items, and APS incorporating PM2.5, PM2.5-10, PM10, NO2, and NOx was calculated to assess the joint exposure level. The outcome of the incident COPD was identified through the in-patient hospital register. The associations of RRS and APS with COPD were examined by Cox proportional hazards regression. RESULTS: The risk of COPD reached its highest in the fourth quartile of the RRS (adjusted HR: 2.23, 95% CI: 1.76-2.82, P for trend < 0.001). A dose-response manner can also be observed between higher tertile APS with increased COPD risk and the highest risk was found in the third tertile of the APS (adjusted HR: 1.37, 95% CI: 1.19-1.58, P for trend < 0.001). The relative excess risk due to interaction (RERI) of 0.030 (95% CI: 0.012-0.048) showed additive interaction between RRS and APS on COPD was significant. In the joint analysis, the combinations of both higher RRS and APS signified higher incident COPD risk. CONCLUSION: High RRS and high APS were jointly associated with increased COPD risks in a dose-response pattern. Using comprehensive indicators to identify women's reproductive risk factors, together with the control of air pollution, is effective for COPD prevention.

Association between birth weight/joint exposure to ambient air pollutants and type 2 diabetes: a cohort study in the UK Biobank.

Early life events and environmental factors are associated with type 2 diabetes (T2D) development. We assessed the combined effect of birth weight andambient air pollutants, and effect of their interaction on T2D risk. Totally, 6,474 T2D incidents were recorded over an 8.7-year follow-up period. The adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) were 1.31 (1.26, 1.36) for each kilogram decrease in birth weight, and 1.08 (1.05, 1.11) for each standard deviation increase in air pollution score (APS). Birth weight<3000 g amplified the T2D risk associated with high APS. A combination of the lowest birth weight (<2500 g) and the highest quintile of APS led to over two-fold increase in T2D risk (aHR: 2.17; 95% CI: 1.79-2.64). There was a significant additive interaction between them. In conclusion, ambient air pollutants increase the risk for T2D, particularly in populations with low birth weight.

Daily stair climbing, disease susceptibility, and risk of atherosclerotic cardiovascular disease: A prospective cohort study.

BACKGROUND AND AIMS: The associations between intensity of stair climbing and atherosclerotic cardiovascular disease (ASCVD) and how these vary by underlying disease susceptibility are not fully understood. We aim to evaluate the intensity of stair climbing and risk of ASCVD types and whether these vary with the presence of ASCVD risk factors. METHODS: This prospective study used data of 458,860 adult participants from the UK Biobank. Information about stair climbing, sociodemographic, and lifestyle factors was collected at baseline and a resurvey 5 years after baseline. ASCVD was defined as coronary artery disease (CAD), ischemic stroke (IS), or acute complications. Associations between flights of stair climbing and ASCVD were examined as hazard ratios (HRs) from Cox proportional hazards models. The modification role of disease susceptibility on such associations was assessed by analyses stratified by levels of genetic risk score (GRS), 10-year risks of ASCVD, and self-reported family history of ASCVD. RESULTS: During a median of 12.5 years of follow-up, 39,043 ASCVD, 30,718 CAD, and 10,521 IS cases were recorded. Compared with the reference group (reported climbing stairs 0 times/day at baseline), the multivariable-adjusted HRs for ASCVD were 0.97 (95% CI, 0.93-1.01), 0.84 (0.82-0.87), 0.78 (0.75-0.81), 0.77 (0.73-0.80) and 0.81 (0.77-0.85) for stair climbing of 1-5, 6-10, 11-15, 16-20 and ≥21 times/day, respectively. Comparable results were obtained for CAD and IS. When stratified by different disease susceptibility based on the GRS for CAD/IS, 10-year risk, and family history of ASCVD, the protection association of stair climbing was attenuated by increasing levels of disease susceptibility. Furthermore, compared with people who reported no stair climbing (<5 times/d) at two examinations, those who climbed stairs at baseline and then stopped at resurvey experienced a 32% higher risk of ASCVD (HR 1.32, 95% CI:1.06-1.65). CONCLUSIONS: Climbing more than five flights of stairs (approx 50 steps) daily was associated with a lower risk of ASCVD types independent of disease susceptibility. Participants who stopped stair climbing between baseline and resurvey had a higher risk of ASCVD compared with those who never climbed stairs.

Association of TyG index with hypertension in Chinese adults: the China Health Examination Collaborative Study (CHEC Study).

BACKGROUND AND OBJECTIVES: We aimed to investigate the association of triglyceride-glucose (TyG) index with hypertension and compare the discriminative power of the TyG index, lipid, glycemic parameters for hypertension using the China Health Examination Collaborative study (CHEC Study). METHODS AND STUDY DESIGN: Data were collected at Ningbo Mingzhou Hospital and Beijing physical examination center from the CHEC Study during 2014 and 2021. Participants with ≥2 medical check-up times were included. The TyG index is the logarithmized product of fasting triglyceride and glucose. Generalised estimation equation (GEE) model was used to evaluate the association between the TyG index, lipid parameters, glycemic parameters and hypertension. Receiver operating characteristic (ROC) analysis was performed to explore the predictive ability of TyG index on hypertension at different years of medical check-up. RESULTS: 112,902 participants with an average age of 42.8 years were recruited in the study, 36,839 participants developed hypertension over the 8-year period. GEE model analysis showed that the ORs with 95% CI of hypertension were 3.35 (3.15-3.57), 1.86 (1.76-1.95), 1.67 (1.58-1.78), 1.45 (1.33-1.58), 1.24 (1.19-1.29), 0.92 (0.86-0.99), and 1.90 (1.83-1.97) in the highest versus lowest quintiles of TyG index, TG/HDL-C ratio, TG, TC, LDL-C, HDL-C and FPG in model 2. The area under the ROC curve of the overall years of medical check-up was signifi-cantly higher than a particular year in predicting hypertension (AUC: 0.883, p < 0.05). CONCLUSIONS: TyG index is associated with hypertension and shows the superior discriminative ability for hypertension compared with lipid and glycemic parameters.

Leisure-Time Television Viewing and Computer Use, Family History, and Incidence of Dementia.

INTRODUCTION: Time spent on screen-based sedentary activities is significantly associated with dementia risk, however, whether the associations vary by family history (FHx) of dementia is currently unknown. We aimed to examine independent associations of two prevalent types of screen-based sedentary activities (television [TV] viewing and computer use) with dementia and assess the modifying effect of FHx. METHODS: We included 415,048 individuals free of dementia from the UK Biobank. Associations of TV viewing, computer use, and FHx with dementia risk were determined using Cox regression models. We estimated both multiplicative- and additive-scale interactions between TV viewing and computer use and FHx. RESULTS: During a median follow-up of 12.6 years, 5,549 participants developed dementia. After adjusting for potential confounding factors, we observed that moderate (2-3 h/day; hazard ratio [HR] 1.13, 95% confidence interval 0.03-1.23) and high (>3 h/day; 1.33, 1.21-1.46) TV viewing was associated with a higher dementia risk, compared with low (0-1 h/day) TV viewing. Using restricted cubic spline models, the relationship of TV viewing with dementia was nonlinear (relative to 0 h/day; p for nonlinear = 0.005). We found that >3 h/day of TV viewing was associated with a 42% (1.42, 1.18-1.71) higher dementia risk in participants with FHx while a 30% (1.30, 1.17-1.45) in those without FHx. For computer use, both low (0 h/day; 1.41, 1.33-1.50) and high (>2 h/day; 1.17, 1.05-1.29) computer use were associated with elevated dementia risk, compared with moderate (1-2 h/day) computer use. We observed a J-shaped relationship with dementia (relative to 2 h/day; p for nonlinear <0.001). Compared with 1-2 h/day of computer use, the HRs of dementia were 1.46 (1.29-1.65) and 1.10 (0.90-1.36) for 0 h/day and >2 h/day of computer use in participants with FHx, respectively, while the corresponding HRs were 1.40 (1.30-1.50) and 1.19 (1.06-1.33) in those without FHx. We observed a positive additive interaction (RERI 0.29, 0.06-0.53) between computer use and FHx, while little evidence of interaction between TV viewing and FHx. CONCLUSIONS: The time spent on TV viewing and computer use were independent risk factors for dementia, and the adverse effects of computer use and FHx were additive. Our findings point to new behavioral targets for intervention on preventing an early onset of dementia, especially for those with FHx.

Genome-wide polygenic risk score, cardiometabolic risk factors, and type 2 diabetes mellitus in the Chinese population.

OBJECTIVE: Type 2 diabetes (T2D) is caused by both genetic and cardiometabolic risk factors. However, the magnitude of the genetic predisposition of T2D in the Chinese population remains largely unknown. METHODS: This study included 93,488 participants from the China Kadoorie Biobank, and multiple polygenic risk scores (PRS) were calculated. A common cardiometabolic risk score (CRS) using smoking, alcohol consumption, physical activity, diet, obesity, blood pressure, and blood lipids was constructed to investigate the effects of cardiometabolic risk factors on T2D. Furthermore, an equation based on ideal PRS, CRS, and their interaction was established to explore the combined effects on T2D. RESULTS: An ideally fitting PRS model (variance explained, R2 = 7.6%) was reached based on multiple PRS calculation methods. An additive interaction between PRS and CRS (coefficient = 28%, 95% CI: 0.20-0.36, p < 0.001) was found. The R2 of the T2D predictive model could increase to 8.3% when CRS and the interaction terms of PRS × CRS were considered. In the etiological composition of T2D, the ratio of genetic risk effect, cardiometabolic risk effect, and interaction between genetic and cardiometabolic factors was 67:16:17. CONCLUSIONS: This study identified an ideally fitting PRS model for identifying and predicting the risk of T2D suitable for the Chinese population. The quantified proportional structure of genetic risk factors, cardiometabolic risk factors, and their interaction was detected, which elucidated the critical effect of genetic factors.

25-hydroxyvitamin D concentrations and risk of incident dementia, mild cognitive impairment, and delirium in 443,427 UK Biobank participants.

This study aimed to investigate the association between serum 25-hydroxyvitamin D (25(OH)D) levels and dementia, mild cognitive impairment (MCI), and delirium. Participants from the United Kingdom (UK) Biobank with complete information on serum 25(OH)D concentrations were enrolled. Dementia, MCI and delirium were defined using the UK Biobank algorithm. 443,427 participants with a mean (standard deviation) age of 56.8 (8.0) years were included in this study. Based on Cox regression models, serum 25(OH)D concentrations were inversely associated with the risk of dementia, MCI, and delirium in a dose-dependent manner after adjusting for demographics (P-trend <0.001). In comparison with 25(OH)D levels less than 32.4 nmol/L, participants with the highest 25(OH)D levels (i.e., >64.4 nmol/L) had the lowest risk of dementia (hazards ratio [HR]: 0.58, 95% confidence interval [CI] 0.49-0.69, P<0.001), MCI (HR: 0.55, 95% CI 0.37-0.84, P=0.005), and delirium (HR: 0.63, 95% CI 0.51-0.79, P<0.001). These results were consistent with the sensitivity analysis, in which participants with events occurring within the first two years of follow-up were excluded. This study found that a lower serum 25(OH)D concentration was significantly associated with a higher risk of dementia (including Alzheimer's disease and vascular dementia), MCI, and delirium.

Blood phytosterols in relation to cardiovascular diseases and mediating effects of blood lipids and hematological traits: a Mendelian randomization analysis.

BACKGROUND: Short-term clinical trials have shown the cholesterol-lowering potentials of phytosterols, but their impacts on cardiovascular disease (CVD) remain controversial. This study used the Mendelian randomization (MR) to investigate the relationships between genetic predisposition to blood sitosterol concentration and 11 CVD endpoints, along with the potential mediating effects of blood lipids and hematological traits. METHODS: Random-effect inverse-variance weighted method was used as the main analysis of MR. Genetic instruments of sitosterol (seven SNPs, F = 253, and R2 = 15.4 %) were derived from an Icelandic cohort. Summary-level data of the 11 CVDs were obtained from UK Biobank, FinnGen, and publicly available genome-wide association study results. RESULTS: Genetically predicted one unit increment in log-transformed blood total sitosterol was significantly associated with a higher risk of coronary atherosclerosis (OR: 1.52; 95 % CI: 1.41, 1.65; n = 667,551), myocardial infarction (OR: 1.40; 95 % CI: 1.25, 1.56; n = 596,436), all coronary heart disease (OR: 1.33; 95 % CI: 1.22, 1.46; n = 766,053), intracerebral hemorrhage (OR: 1.68; 95 % CI: 1.24, 2.27; n = 659,181), heart failure (OR: 1.16; 95 % CI: 1.08, 1.25; n = 1,195,531), and aortic aneurysm (OR: 1.74; 95 % CI: 1.42, 2.13; n = 665,714). Suggestive associations were observed for an increased risk of ischemic stroke (OR: 1.06; 95 % CI: 1.01, 1.12; n = 2,021,995) and peripheral artery disease (OR: 1.20; 95 % CI: 1.05, 1.37; n = 660,791). Notably, blood non-high-density lipoprotein cholesterol (nonHDL-C) and apolipoprotein B mediated about 38-47 %, 46-60 %, and 43-58 % of the associations between sitosterol and coronary atherosclerosis, myocardial infarction, and coronary heart disease, respectively. However, the associations between sitosterol and CVDs were less likely to depend on hematological traits. CONCLUSION: The study suggests that genetic predisposition to higher blood total sitosterol is linked to a greater risk of major CVDs. Moreover, blood nonHDL-C and apolipoprotein B might mediate a significant proportion of the associations between sitosterol and coronary diseases.