The causal effect of Alzheimer's disease and family history of Alzheimer's disease on non-ischemic cardiomyopathy and left ventricular structure and function: a Mendelian randomization study.

Background: Previous studies have shown that Alzheimer's disease (AD) can cause myocardial damage. However, whether there is a causal association between AD and non-ischemic cardiomyopathy (NICM) remains unclear. Using a comprehensive two-sample Mendelian randomization (MR) method, we aimed to determine whether AD and family history of AD (FHAD) affect left ventricular (LV) structure and function and lead to NICM, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). Methods: The summary statistics for exposures [AD, paternal history of AD (PH-AD), and maternal history of AD (MH-AD)] and outcomes (NICM, HCM, DCM, and LV traits) were obtained from the large European genome-wide association studies. The causal effects were estimated using inverse variance weighted, MR-Egger, and weighted median methods. Sensitivity analyses were conducted, including Cochran's Q test, MR-Egger intercept test, MR pleiotropy residual sum and outlier, MR Steiger test, leave-one-out analysis, and the funnel plot. Results: Genetically predicted AD was associated with a lower risk of NICM [odds ratio (OR) 0.9306, 95% confidence interval (CI) 0.8825-0.9813, p = 0.0078], DCM (OR 0.8666, 95% CI 0.7752-0.9689, p = 0.0119), and LV remodeling index (OR 0.9969, 95% CI 0.9940-0.9998, p = 0.0337). Moreover, genetically predicted PH-AD was associated with a decreased risk of NICM (OR 0.8924, 95% CI 0.8332-0.9557, p = 0.0011). MH-AD was also strongly associated with a decreased risk of NICM (OR 0.8958, 95% CI 0.8449-0.9498, p = 0.0002). Different methods of sensitivity analysis demonstrated the robustness of the results. Conclusion: Our study revealed that AD and FHAD were associated with a decreased risk of NICM, providing a new genetic perspective on the pathogenesis of NICM.

Association of anaemia on heart failure and left ventricular function: A bidirectional Mendelian randomization study.

AIMS: Observational studies have suggested that anaemia is associated with an increased risk of heart failure (HF). But the potential causal association is not clear. We aimed to investigate the association between anaemia and HF risk. METHODS AND RESULTS: A Mendelian randomization (MR) analysis was performed to confirm the causal association of anaemia with the risk of HF and left ventricular structure and function. Furthermore, a reverse-direction MR analyses was conducted to assess the causal effect of HF on anaemia. The MR analysis indicated that genetically predicted anaemia is associated with the increased risk of HF (meta: odd ratio (OR) = 1.12; 95% confidence interval (CI) [1.04, 1.20]; P = 0.002), and left ventricular mass index (ß = 1.051; 95% CI [0.384, 1.718]; P = 0.002), left ventricular mass (ß = 2.063; 95% CI [0.578, 3.547]; P = 0.006), left atrial minimum volume (ß = 0.076; 95% CI [0.008, 0.143]; P = 0.028), and left atrial maximum volume (ß = 0.090; 95% CI [0.023, 0.157]; P = 0.009). In the reverse-direction MR analyses, we found that genetic susceptibility to HF was significantly associated with the increased risk of anaemia (meta: OR = 1.40; 95% CI [1.24, 1.59]; P = 1.79 × 10-7 ). CONCLUSIONS: This MR study supports the genetic evidence that there is bidirectional causality between anaemia and the risk of HF as well as anaemia may cause left ventricular hypertrophy and enlargement of the left atrium. Considering the adverse causal effects between the two diseases, more attention should be paid to the prevention and treatment of anaemia in patients with HF.

Evaluation of left ventricular structural and functional abnormalities and vascular calcification in kidney transplant recipients and the effect of bone metabolism on them / 中华器官移植杂志

Objective:To evaluate left ventricular structural and functional abnormalities and vascular calcification in kidney transplant (KT) recipients, explore their influencing factors and examine the effects of mineral and bone disorders.Methods:From January 2017 to December 2019, retrospective analysis was performed for 292 KT recipients. Biochemical markers of bone metabolism, bone mineral density (BMD), left ventricular hypertrophy (LVH), left ventricular ejection fraction (LVEF), left ventricular diastolic function, coronary artery calcification (CAC) score and thoracic aortic calcification (TAC) score were assessed. Linear regression and binary Logistic regression analyses were employed for evaluating the influencing factors of cardiovascular parameters and the influence of abnormal mineral and bone metabolism.Results:Postoperative abnormalities in mineral and bone disorders were manifested mostly as hypercalcemia (8.9%, 26/292), hypophosphatemia (27.1%, 79/292), low 25-hydroxyvitamin D (25(OH)vitD) (67.0%, 196/292), hyperparathyroidismhigh parathyroid hormone (PTH) (50.6%, 148/292), elevated bone turnover markers and bone loss rate of 25%-30%. The prevalence of LVH, LVEF<50%, left ventricular diastolic dysfunction, high CAC score and high TAC score were 39.9%(116/292), 0%, 13.1%(38/292), 17.3%(50/292) and 39.9%(116/292) respectively. The results of multivariate analysis indicated that LVH was correlated positively with hypertension and serum calcium (Ca) (95% CI: 1.242-28.080, P=0.026; 95% CI: 1.714-277.584, P=0.018); LVEF was correlated positively with lumbar vertebrae BMD (95% CI: 0.000 1-0.005 5, P=0.041); Left ventricular diastolic dysfunction was correlated positively with age, diabetes and parathyroid hyperplasia/nodules (95% CI: 1.050-1.176, P<0.001; 95% CI: 2.118-43.813, P=0.003 and 95% CI: 1.419-9.103, P=0.007); High CAC score was correlated positively with recipient age and dialysis time (95% CI: 1.036-1.160, P=0.001; 95% CI: 1.009-1.041, P=0.002); High TAC score was correlated positively with age (95% CI: 1.095-1.215, P<0.001). Correlation analysis indicated that TAC was correlated positively with serum Ca ( r=0.233, P=0.003), bone-specific alkaline phosphatase (BALP)( r=0.325, P<0.001) and type Ⅰ collagen cross-linked N-terminal peptide (NTX)( r=0.204, P=0.011) and negatively with femoral neck BMD ( r=0.194, P=0.017). Conclusions:There is a high prevalence of left ventricular structural and functional abnormalities and vascular calcification. It is closely correlated with mineral and bone disorders.

Effects of glycemic traits on left ventricular structure and function: a mendelian randomization study.

BACKGROUND: Adverse ventricular structure and function is a key pathogenic mechanism of heart failure. Observational studies have shown that both insulin resistance (IR) and glycemic level are associated with adverse ventricular structure and function. However, whether IR and glycemic level are causally associated with cardiac structure and function remains unclear. METHODS: Genetic variants for IR, fasting insulin, HbA1c, and fasting glucose were selected based on published genome-wide association studies, which included 188,577, 108,557, 123,665, and 133,010 individuals of European ancestry, respectively. Outcome datasets for left ventricular (LV) parameters were obtained from UK Biobank Cardiovascular Magnetic Resonance sub-study (n = 16,923). Mendelian randomization (MR) analyses with the inverse-variance weighted (IVW) method were used for the primary analyses, while weighted median, MR-Egger, and MR-PRESSO were used for sensitivity analyses. Multivariable MR analyses were also conducted to examine the independent effects of glycemic traits on LV parameters. RESULTS: In the primary IVW MR analyses, per 1-standard deviation (SD) higher IR was significantly associated with lower LV end-diastolic volume (ß = - 0.31 ml, 95% confidence interval [CI] - 0.48 to - 0.14 ml; P = 4.20 × 10-4), lower LV end-systolic volume (ß = - 0.34 ml, 95% CI - 0.51 to - 0.16 ml; P = 1.43 × 10-4), and higher LV mass to end-diastolic volume ratio (ß = 0.50 g/ml, 95% CI 0.32 to 0.67 g/ml; P = 6.24 × 10-8) after Bonferroni adjustment. However, no associations of HbA1c and fasting glucose were observed with any LV parameters. Results from sensitivity analyses were consistent with the main findings, but with a slightly attenuated estimate. Multivariable MR analyses provided further evidence for an independent effect of IR on the adverse changes in LV parameters after controlling for HbA1c. CONCLUSIONS: Our study suggests that genetic liability to IR rather than those of glycemic levels are associated with adverse changes in LV structure and function, which may strengthen our understanding of IR as a risk factor for heart failure by providing evidence of direct impact on cardiac morphology.

Short-term melatonin supplementation decreases oxidative stress but does not affect left ventricular structure and function in myxomatous mitral valve degenerative dogs.

BACKGROUND: Cardiac wall stress and high oxidative stress are often found in cases of myxomatous mitral valve degenerative (MMVD) disease and can lead to myocardial injuries and cardiac dysfunction. Melatonin, an antioxidant, has been shown to exert cardioprotection in laboratory animal models. However, its effect on metabolic parameters and left ventricular (LV) adaptation in MMVD dogs has rarely been investigated. This clinical trial hypothesized that a melatonin supplement for 4 weeks would improve metabolic parameters, LV structure (diameters and wall thickness), and LV function in MMVD dogs. Blood profiles, echocardiograms, and oxidative stress levels were obtained from 18 dogs with MMVD stage B2 and C at baseline and after prescribed Melatonin (2 mg/kg) for 4 weeks. Eleven dogs with MMVD stage B2 and C, which received a placebo, were evaluated as a control group. RESULTS: In this clinical trial, the baseline plasma malondialdehyde (MDA) was no different between the treatment and placebo groups. The post-treatment plasma MDA levels (4.50 ± 0.63 mg/mL) in the treatment group was significantly decreased after 4 weeks of melatonin supplementation compared to pre-treatment levels (7.51 ± 1.11 mg/mL) (P = 0.038). However, blood profiles and LV structure and function investigated using echocardiography were found not to different between pre-and post-treatment in each group. No adverse effects were observed following melatonin supplementation. CONCLUSIONS: This clinical trial demonstrated that a melatonin supplement for 4 weeks can attenuate oxidative stress levels in MMVD dogs, especially in MMVD stage C, but does not result in LV structural changes or LV function in MMVD dogs of either stage B2 or stage C.

Causal effect of central obesity on left ventricular structure and function in preserved EF population: A Mendelian randomization study.

Background: Observational studies have shown that central obesity is associated with adverse cardiac structure and function. However, causal association between central obesity and left ventricular (LV) structure and function in preserved ejection fraction (EF) population is still uncertain. Methods: Genome-wide association studies summary data of waist circumference adjusted for body mass index (WCadjBMI) and waist-to-hip ratio adjusted for body mass index (WHRadjBMI) were selected as instrumental variables from the Genetic Investigation of Anthropometric Traits (GIANT) Consortium (n = 224,459). Outcome datasets for LV parameters including LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), LV ejection fraction (LVEF), LV mass (LVM), and LV mass-to-end-diastolic volume ratio (LVMVR) were obtained from the participants without prevalent myocardial infarction or heart failure (LVEF ≥ 50%) in UK Biobank Cardiovascular Magnetic Resonance sub-study (n = 16,923). Two-sample Mendelian randomization (MR) was performed with the inverse-variance weighted (IVW) method as the primary estimate and with the weighted median and MR-Egger as the supplemental estimates. Sensitivity analysis was used to assess the heterogeneity and pleiotropic bias in the MR results. Results: In the IVW analysis, every 1-standard deviation (SD) higher WHRadjBMI was significantly associated with higher LVMVR (ß = 0.4583; 95% confidence interval [CI]: 0.2921 to 0.6244; P = 6.418 × 10-8) and lower LVEDV (ß = -0.2395; 95% CI: -0.3984 to -0.0807; P = 0.0031) after Bonferroni adjustment. No heterogeneity and horizontal pleiotropy were detected in the analysis. No association of WCadjBMI was found with LVEF, LVEDV, LVESV, LVM, or LVMVR. Conclusion: Our findings provide evidence of significant causal association between WHRadjBMI and adverse changes in LV structure and function in preserved EF population.

Visit-to-Visit Fasting Glucose Variability in Young Adulthood and Cardiac Structure and Function at Midlife: The CARDIA Study.

Glycemic variability was found associated with left ventricular structure and function in type 2 diabetes. But it is still unclear that whether the greater visit-to-visit fasting glucose (FG) variability in young adulthood among the community population is associated with cardiac function alteration and cardiac remodeling at midlife. The community-based prospective cohort study of Coronary Artery Risk in Young Adult (CARDIA) recruited young participants at the baseline age of 18-30 years during the period of 1985-1986 (Year 0). FG was measured at Year 0, 2, 10, 15, 20, and 25. The echocardiographic evaluation of cardiac structure and function was conducted at year 25. A total of 2,600 young adults mean (SD) aged at 24.9 years (3.6) of which 57.3% were women and 46.7% were African Americans had been included in the study. After multivariable adjusted, higher SD of mean FG (SDFG) is associated with lower early peak diastolic septal mitral annular velocity (e') (ß [SE], -0.214 [0.080], P < 0.01) and higher E/e' (ß [SE], 0.307 [0.094], P < 0.01), and higher coefficient of variation of the mean FG (CVFG) is also associated with lower e' (ß [SE], -0.141[0.066], P < 0.05) and higher E/e' (ß [SE], 0.204 [0.078], P < 0.01). The higher average real variation of mean FG (ARVFG) is associated with higher E/e' (ß [SE], 0.178 [0.085], P < 0.05) and higher left ventricular mass index (LVMI) (ß [SE], 1.240 [0.618], P < 0.05). The higher FG variability in young adulthood is associated with the subclinical change of left ventricular (LV) diastolic function at midlife.