Prevalence and risk factors of hyperuricemia among kidney transplant recipients

Prevalence of Musculoskeletal and Metabolic Disorders in Kidney Transplant Recipients: A Systematic Review and Meta-Analysis

Introduction

Musculoskeletal disorders could be associated with metabolic disorders that are common after kidney transplantation, which could reduce the quality of life of patients. The aim of this study was to assess the prevalence of both musculoskeletal and metabolic disorders in kidney transplant patients.

Methods

MEDLINE, CINAHL, Cochrane Library, EMBASE and Web of Science were searched from their inception up to June 2023. DerSimonian and Laird random-effects method was used to calculate pooled prevalence estimates and their 95% confidence intervals (CIs).

Results

21,879 kidney transplant recipients from 38 studies were analysed. The overall proportion of kidney transplant patients with musculoskeletal disorders was 27.2% (95% CI: 18.4-36.0), with low muscle strength (64.5%; 95% CI: 43.1-81.3) being the most common disorder. Otherwise, the overall proportion of kidney transplant patients with metabolic disorders was 37.6% (95% CI: 21.9-53.2), with hypovitaminosis D (81.8%; 95% CI: 67.2-90.8) being the most prevalent disorder.

Conclusion

The most common musculoskeletal disorders were low muscle strength, femoral osteopenia, and low muscle mass. Hypovitaminosis D, hyperparathyroidism, and hyperuricemia were also the most common metabolic disorders. These disorders could be associated with poorer quality of life in kidney transplant recipients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier [CRD42023449171].

Serum uric acid levels in kidney transplant recipients: A cause for concern? A review of recent literature

The impact of elevated serum uric acid levels i.e., hyperuricemia, on native and transplant chronic kidney disease progression has been debated. This literature review presents an analysis of multiple studies exploring the relationship between serum uric acid levels and kidney transplant outcomes. The review includes a summary of the pathophysiology of hyperuricemia and gout, a review of urate-lowering therapies, and an appraisal of multiple studies examining the association or lack thereof between serum uric acid level and kidney transplant outcomes. Based on these studies, elevated serum uric acid levels may contribute to CKD progression in kidney transplant recipients. In this review, we also summarize current literature to highlight risk factors associated with hyperuricemia as well as the need for further investigation to monitor and manage hyperuricemia in kidney transplant recipients.

Handgrip strength as a predictor of incident hypertension in the middle-aged and older population: The TCLSIH cohort study

OBJECTIVES

The independent role of muscular strength in the prevention of chronic disease is increasingly being recognized. However, no cohort study has assessed the relationship between handgrip strength and the incidence of hypertension among the middle-aged and older population. The aim of this prospective cohort study was to investigate whether handgrip strength is related to incident hypertension among people aged 40 years and over.

STUDY DESIGN

This prospective cohort study (n = 8,480) was performed between 2013 and 2019 as part of the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study, Tianjin, China.

MAIN OUTCOME MEASURES

Participants without baseline hypertension were followed up for ~6 years (median 4.0 years). Hypertension was defined according to the JNC7 criteria. Handgrip strength was measured using a hydraulic handheld dynamometer. Adjusted Cox proportional hazards regression models were used to assess the relationships between weight-adjusted handgrip strength and the risk of incident hypertension.

RESULTS

The incidence rate of hypertension per 1000 person-years was 70. The fully adjusted hazards ratios (95% confidence interval) of the incidence of hypertension for increasing quartiles of weight-adjusted handgrip strength were: 1.00(reference), 0.84 (0.75-0.95), 0.78 (0.69-0.88), and 0.66 (0.58-0.75) (P for trend<0.0001). Moreover, the adjusted hazards ratio (95% confidence interval) of incident hypertension for per unit increase in weight-adjusted handgrip strength was 0.17 (0.10-0.27) (P<0.0001). Similar results were observed in males and females.

CONCLUSIONS

The present cohort study is the first to find that high weight-adjusted handgrip strength, but not absolute handgrip strength, is significantly and independently related to low risk of incident hypertension among the middle-aged and older population.

Predictors of Hyperuricemia after Kidney Transplantation: Association with Graft Function

Background and objectives: In kidney transplant recipients (KTR), hyperuricemia (HU) is a commonly-observed phenomenon, due to calcineurin inhibitors and reduced kidney graft function. Factors predicting HU, and its association with graft function, remains equivocal. Materials and Methods: We conducted a retrospective longitudinal study to assess factors associated with HU in KTR, and to determine risk factors associated with graft function, measured as glomerular filtration rate (GFR). Moreover, GFR > 60 mL/min/1.73 m² was considered normal. HU was defined as a serum uric acid level of > 416 μmol/L (4.70 mg/dL) in men and >357 μmol/L (4.04 mg/dL) in women, or xanthine-oxidase inhibitor use. We built multiple logistic regression models to assess predictors of HU in KTR, as well as the association of demographic, clinical, and biochemical parameters of patients with normal GFR after a three-year follow-up. We investigated the effect modification of this association with HU. Results: There were 144 patients (mean age 46.6 ± 13.9), with 42.4% of them having HU. Predictors of HU in KTR were the presence of cystic diseases (OR = 9.68 (3.13; 29.9)), the use of diuretics (OR = 4.23 (1.51; 11.9)), and the male gender (OR = 2.45 (1.07; 5.56)). Being a younger age, of female gender, with a normal BMI, and the absence of diuretic medications increased the possibility of normal GFR. HU was the effect modifier of the association between demographic, clinical, and biochemical factors and a normal GFR. Conclusions: Factors associated with HU in KTR: Presence of cystic diseases, diuretic use, and male gender. HU was the effect modifier of the association of demographic, clinical, and biochemical factors to GFR.

[Urinary lithiasis in renal transplant recipient]

OBJECTIVES

To report epidemiology and characteristics of urinary lithiasis and its management in kidney allograft at the time of organ procurement or after kidney transplantation.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords (MESH): urinary lithiasis, stone, kidney transplantation. Publications obtained were selected based on methodology, language, date of publication (last 10 years) and relevance. Prospective and retrospective studies, in English or French, review articles; meta-analysis and guidelines were selected and analyzed. This search found 58 articles. After reading, 37 were included in the text based on their relevance.

RESULTS

Frequency of urinary lithiasis in renal transplant recipient is similar to those observed in the general population. Generally, urinary lithiasis of the graft is asymptomatic because of renal denervation after organ procurement and transplantation. Nevertheless, this situation may be at high risk due to the immunosuppressed state of the recipient with a unique functioning kidney. Most of the time, the diagnosis is incidental during routine post-transplantation follow-up. Management of urolithiasis in renal transplant recipient is similar to that performed in general population.

CONCLUSION

Due to its potential severity in transplanted immunosuppressed patients with a sole kidney, urolithiasis requires expert urological management.

Hyperuricemia and chronic kidney disease: an enigma yet to be solved

The role of uric acid (UA) on the pathogenesis and progression of chronic kidney disease (CKD) remains controversial. Experimental and clinical studies indicate that UA is associated with several risk factors of CKD including diabetes, hypertension, oxidative stress, and inflammation and hyperuricemia could be considered as a common dominator linking CKD and cardiovascular disease. Notably, the impact of serum UA levels on the survival of CKD, dialysis patients, and renal transplant recipients is also a matter of debate, as there are conflicting results from clinical studies. At present, there is no definite data whether UA is causal, compensatory, coincidental or it is only an epiphenomenon in these patients. In this article, we attempt to review and elucidate the dark side of this old molecule in CKD and renal transplantation.