Background: The role of high-density lipoprotein (HDL) function in cardiovascular disease represents an important emerging concept. The present study investigated whether HDL anti-inflammatory capacity is prospectively associated with first cardiovascular events in the general population. Methods: HDL anti-inflammatory capacity was determined as its ability to suppress TNFα (tumor necrosis factor α)–induced VCAM-1 (vascular cell adhesion molecule-1) mRNA expression in endothelial cells in vitro (results expressed as achieved percent reduction by individual HDL related to the maximum TNFα effect with no HDL present). In a nested case-control design of the PREVEND (Prevention of Renal and Vascular End Stage Disease) study, 369 cases experiencing a first cardiovascular event (combined end point of death from cardiovascular causes, ischemic heart disease, nonfatal myocardial infarction, and coronary revascularization) during a median of 10.5 years of follow-up were identified and individually matched to 369 controls with respect to age, sex, smoking status, and HDL cholesterol. Baseline samples were available in 340 cases and 340 matched controls. Results: HDL anti-inflammatory capacity was not correlated with HDL cholesterol or hsCRP (high-sensitivity C-reactive protein). HDL anti-inflammatory capacity was significantly lower in cases compared with controls (31.6% [15.7–44.2] versus 27.0% [7.4–36.1]; P 0.05). When combining these 2 HDL function metrics in 1 model, both were significantly and independently associated with incident cardiovascular disease in a fully adjusted model (efflux: OR per 1 SD, 0.74; P =0.002; anti-inflammatory capacity: OR per 1 SD, 0.66; P <0.001). Adding HDL anti-inflammatory capacity improved risk prediction by the Framingham risk score, with a model likelihood-ratio statistic increase from 10.50 to 20.40 ( P =0.002). Conclusions: The HDL anti-inflammatory capacity, reflecting vascular protection against key steps in atherogenesis, was inversely associated with incident cardiovascular events in a general population cohort, independent of HDL cholesterol and HDL cholesterol efflux capacity. Adding HDL anti-inflammatory capacity to the Framingham risk score improves risk prediction.
27 August 2018 in Nephrology Dialysis Transplantation
Background: It currently remains understudied whether low consumption of fruits and vegetables after kidney transplantation may be a modifiable cardiovascular risk factor. We aimed to investigate the associations between consumption of fruits and vegetables and cardiovascular mortality in renal transplant recipients (RTRs).Methods: Consumption of fruits and vegetables was assessed in an extensively phenotyping cohort of RTRs. Multivariable-adjusted Cox proportional hazards regression analyses were performed to assess the risk of cardiovascular mortality.Results: We included 400 RTRs (age 52 ± 12 years, 54% males). At a median follow-up of 7.2 years, 23% of RTRs died (53% were due to cardiovascular causes). Overall, fruit consumption was not associated with cardiovascular mortality {hazard ratio [HR] 0.82 [95% confidence interval (CI) 0.60–1.14]; P = 0.24}, whereas vegetable consumption was inversely associated with cardiovascular mortality [HR 0.49 (95% CI 0.34–0.71); P < 0.001]. This association remained independent of adjustment for several potential confounders. The association of fruit consumption with cardiovascular mortality was significantly modified by estimated glomerular filtration rate (eGFR; Pinteraction = 0.01) and proteinuria (Pinteraction = 0.01), with significant inverse associations in patients with eGFR > 45 mL/min/1.73 m2 [HR 0.56 (95% CI 0.35–0.92); P = 0.02] or the absence of proteinuria [HR 0.62 (95% CI 0.41–0.92); P = 0.02].Conclusions: In RTRs, a relatively higher vegetable consumption is independently and strongly associated with lower cardiovascular mortality. A relatively higher fruit consumption is also associated with lower cardiovascular mortality, although particularly in RTRs with eGFR > 45 mL/min/1.73 m2 or an absence of proteinuria. Further studies seem warranted to investigate whether increasing consumption of fruits and vegetables may open opportunities for potential interventional pathways to decrease the burden of cardiovascular mortality in RTRs.
1 February 2018 in European Journal of Internal Medicine
Atherosclerotic cardiovascular disease (CVD) represents the largest cause of mortality in end-stage renal disease (ESRD). CVD in ESRD is not explained by classical CVD risk factors such as HDL cholesterol mass levels making functional alterations of lipoproteins conceivable. HDL functions in atheroprotection by promoting reverse cholesterol transport (RCT), comprising cholesterol efflux from macrophage foam cells, uptake into hepatocytes and final excretion into the feces. ESRD-HDL (n = 15) were compared to healthy control HDL (n = 15) for their capacity to promote in vitro (i) cholesterol efflux from THP-1 macrophage foam cells and (ii) SR-BI-mediated selective uptake into ldla[SR-BI] cells as well as (iii) in vivo RCT. Compared with HDL from controls, ESRD-HDL displayed a significant reduction in mediating cholesterol efflux (p < 0.001) and SR-BI-mediated selective uptake (p < 0.01), two key steps in RCT. Consistently, also the in vivo capacity of ESRD-HDL to promote RCT when infused into wild-type mice was significantly impaired (p < 0.01). In vitro oxidation of HDL from healthy controls with hypochloric acid was able to fully mimic the impaired biological activities of ESRD-HDL. In conclusion, we demonstrate that HDL from ESRD patients is dysfunctional in key steps as well as overall RCT, likely due to oxidative modification.
Are levels of trimethylamine-N-oxide (TMAO) in human follicular fluid (FF) related to IVF outcomes? Higher levels of TMAO are a negative predictor of oocyte fertilization and embryo quality. TMAO is a metabolic product of dietary choline and l-carnitine produced via subsequent enzymatic modifications by the intestinal microbiota and hepatocytes. TMAO promotes inflammatory and oxidative stress pathways and has been characterized as a causative biomarker for the development of cardiometabolic disease. For the present cross-sectional study, samples (FF and plasma) from 431 modified natural cycle (MNC)-IVF cycles of 132 patients were collected prospectively between October 2014 and March 2018 in a single academic medical center. TMAO and its precursors (choline, l-carnitine and gamma-butyrobetaine) were measured by ultra-high-performance liquid chromatography/mass spectrometry in (i) matched FF and plasma from 63 MNC-IVF cycles, in order to compare metabolite levels in the two matrices and (ii) FF from 232 MNC-IVF cycles in which only one oocyte was retrieved at follicular puncture. The association between metabolite levels and oocyte fertilization, embryo fragmentation percentage, embryo quality and the occurrence of pregnancy was analyzed using multilevel generalized estimating equations with adjustment for patient and cycle characteristics. The level of choline was higher in FF as compared to matched plasma (P < 0.001). Conversely, the levels of TMAO and gamma-butyrobetaine were lower in FF as compared to plasma (P = 0.001 and P = 0.075, respectively). For all metabolites, there was a positive correlation between FF and plasma levels. Finally, levels of TMAO and its gut-derived precursor gamma-butyrobetaine were lower in FF from oocytes that underwent normal fertilization (TMAO: odds ratio [OR] 0.66 [0.49–0.90], P = 0.008 per 1.0-μmol/L increase; gamma-butyrobetaine: OR 0.77 [0.60–1.00], P = 0.047 per 0.1-μmol/L increase) and developed into top-quality embryos (TMAO: OR 0.56 [0.42–0.76], P < 0.001 per 1.0-μmol/L increase; gamma-butyrobetaine: OR 0.79 [0.62–1.00], P = 0.050 per 0.1-μmol/L increase) than in FF from oocytes of suboptimal development. The individual contributions of diet, gut bacteria and liver to the metabolite pools have not been quantified in this analysis. More research on the contribution of diet and the effect of gut bacteria on FF TMAO is warranted. Since TMAO integrates diet, microbiota and genetic setup of the person, our results indicate potential important clinical implications for its use as biomarker for lifestyle interventions to improve fertility. No external funding was received for this project. The Department of Obstetrics and Gynecology of the University Medical Center Groningen received an unrestricted educational grant of Ferring Pharmaceutical BV, the Netherlands. The authors have no other conflicts of interest. Netherlands Trial Register number NTR4409.
In renal transplant recipients (RTRs), new-onset diabetes after transplantation (NODAT) is a frequent and serious complication limiting survival of graft and patient. However, the underlying pathophysiology remains incompletely understood. In vitro and in preclinical models, HDL can preserve β-cell function, largely by mediating cholesterol efflux, but this concept has not been evaluated in humans. This study investigated whether baseline cholesterol efflux capacity (CEC) in RTRs is associated with incident NODAT during follow-up. This prospective longitudinal study included 405 diabetes-free RTRs with a functioning graft for >1 year. During a median (interquartile range) follow-up of 9.6 (6.6–10.2) years, 57 patients (14.1%) developed NODAT. HDL CEC was quantified using incubation of human macrophage foam cells with apolipoprotein B–depleted plasma. Baseline CEC was significantly lower in patients developing NODAT during follow-up (median 6.84% [interquartile range 5.84–7.50%]) compared with the NODAT-free group (7.44% [6.46–8.60%]; P = 0.001). Kaplan-Meier analysis showed a lower risk for incident NODAT with increasing sex-stratified tertiles of HDL efflux capacity (P = 0.004). Linear regression analysis indicated that CEC is independently associated with incident NODAT (P = 0.04). In Cox regression analyses, CEC was significantly associated with NODAT (hazard ratio 0.53 [95% CI 0.38–0.76]; P < 0.001), independent of HDL cholesterol levels (P = 0.015), adiposity (P = 0.018), immunosuppressive medication (P = 0.001), and kidney function (P = 0.01). Addition of CEC significantly improved the predictive power of the Framingham Diabetes Risk Score (P = 0.004). This study establishes HDL CEC as a strong predictor of NODAT in RTRs, independent of several other recognized risk factors.