Polyphenols and Novel Insights Into Post-kidney Transplant Complications and Cardiovascular Disease: A Narrative Review

Time for Change: A 3-Year Prospective Study on Mediterranean Diet Adherence and Body Composition in Kidney Transplant Recipients

BACKGROUND

The aim of this prospective follow-up study was to evaluate changes in body composition parameters and Mediterranean diet (MeDi) adherence among kidney transplant recipients (KTRs) over a three-year period. Additionally, this study sought to investigate the associations between these changes and clinical parameters, including laboratory parameters, new onset of diseases, and death outcome.

METHODS

A total of 116 KTRs were initially assessed in 2019 and subsequently re-evaluated in 2022. The Mediterranean Diet Serving Score (MDSS) was used to assess dietary adherence to the MeDi at baseline and follow-up assessments. Bioelectrical impedance analysis was used to assess body composition and clinical outcomes were assessed by the data available from medical charts.

RESULTS

After three years, MeDi adherence significantly decreased (p = 0.028) from 15 (18.29%) to 5 (6%), with dominantly lower adherence for vegetable, fruit, legume, red meat, olive oil and fish intake. Regarding body composition parameters, the most prominent change was seen in muscle mass, which deteriorated from 41.77% (IQR 6.46) to 39% (IQR 6.14; p = 0.004). However, changes in fat mass level were not significant in the follow-up period. Furthermore, cereal intake, fasting blood glucose (FBG), cholesterol level, level of low-density lipoprotein cholesterol (LDL), triglyceride leve and presence of diabetes mellitus lwere shown to be predictive for the decline of skeletal muscle mass. There were no significant changes in the estimated glomerular filtration rate (eGFR) or albuminuria level during the follow-up period. Associations with the death outcome were found for the MeDi-advised intake of eggs (β = -1.06, HR = 0.35, CI (0.14-0.87), p = 0.023), phase angle (PhA) (β = -2.68, HR = 0.07, CI (0.01-0.43), p = 0.004), cholesterol level (β = 0.95, HR = 2.60, CI (1.40-4.70), p = 0.001) and calcium level (β = -7.21, HR = 0.00, CI (0.00-1.50), p = 0.063).

CONCLUSIONS

This study highlights a significant decline in MeDi adherence and skeletal muscle mass among KTRs over a three-year follow-up period, with no notable changes in fat mass or kidney function. The predictors of muscle mass loss and associations with mortality underscore the importance of dietary and clinical management in this population.

Donor-Dependent Variations in Systemic Oxidative Stress and Their Association with One-Year Graft Outcomes in Kidney Transplantation

INTRODUCTION

Oxidative stress has been implicated in complications after kidney transplantation (KT), including delayed graft function (DGF) and rejection. However, its role in long-term posttransplant outcomes remains unclear.

METHODS

We investigated oxidative damage and antioxidant defense dynamics, and their impact on the graft outcomes, in 41 KT recipients categorized by type of donation over 12 months. Oxidative status was determined using OxyScore and AntioxyScore indexes, which comprise several circulating biomarkers of oxidative damage and antioxidant defense. Donor types included donation after brain death (DBD [61.0%]), donation after circulatory death (DCD [26.8%]), and living donation (LD [12.1%]).

RESULTS

There was an overall increase in oxidative damage early after transplantation, which was significantly higher in DCD as compared to DBD and LD recipients. The multivariate adjustment confirmed the independent association of OxyScore and type of deceased donation with DGF, donor kidney function, and induction therapy with antithymocyte globulin. There were no differences in terms of antioxidant defense. Lower oxidative damage at day 7 predicted better graft function at 1-year posttransplant only in DBD recipients.

CONCLUSION

DCD induced greater short-term oxidative damage after KT, whereas the early levels of oxidative damage were predictive of the graft function 1 year after KT among DBD recipients.

Effectiveness of targeting the NLRP3 inflammasome by using natural polyphenols: A systematic review of implications on health effects

Globally, inflammation and metabolic disorders pose serious public health problems and are major health concerns. It has been shown that natural polyphenols are effective in the treatment of metabolic diseases, including anti-inflammation, anti-diabetes, anti-obesity, neuron-protection, and cardio-protection. NLRP3 inflammasome, which are multiprotein complexes located within the cytosol, play an important role in the innate immune system. However, aberrant activation of the NLRP3 inflammasome were discovered as essential molecular mechanisms in triggering inflammatory processes as well as implicating it in several major metabolic diseases, such as type 2 diabetes mellitus, obesity, atherosclerosis or cardiovascular disease. Recent studies indicate that natural polyphenols can inhibit NLRP3 inflammasome activation. In this review, the progress of natural polyphenols preventing inflammation and metabolic disorders via targeting NLRP3 inflammasome is systemically summarized. From the viewpoint of interfering NLRP3 inflammasome activation, the health effects of natural polyphenols are explained. Recent advances in other beneficial effects, clinical trials, and nano-delivery systems for targeting NLRP3 inflammasome are also reviewed. NLRP3 inflammasome is targeted by natural polyphenols to exert multiple health effects, which broadens the understanding of polyphenol mechanisms and provides valuable guidance to new researchers in this field.

Updated Pathways in Cardiorenal Continuum after Kidney Transplantation

Cardiovascular disease (CVD) remains one of the leading causes for increased morbidity and mortality in chronic kidney disease (CKD). Kidney transplantation is the preferred treatment option for CKD G5. Improved perioperative and postoperative care, personalized immunosuppressive regimes, and refined matching procedures of kidney transplants improves cardiovascular health in the early posttransplant period. However, the long-term burden of CVD is considerable. Previously underrecognized, the role of the complement system alongside innate immunity, inflammaging, structural changes in the glomerular filtration barrier and early vascular ageing also seem to play an important role in the posttransplant management. This review provides up-to-date knowledge on these pathways that may influence the cardiovascular and renal continuum and identifies potential targets for future therapies. Arterial destiffening strategies and the applicability of sodium-glucose cotransporter 2 inhibitors and their role in cardiovascular health after kidney transplantation are also addressed.