Hyperuricemia is associated with a lower glomerular filtration rate in pediatric sickle cell disease patients

Association of Kidney Comorbidities and Acute Kidney Failure With Unfavorable Outcomes After COVID-19 in Individuals With the Sickle Cell Trait

Importance

Sickle cell trait (SCT), defined as the presence of 1 hemoglobin beta sickle allele (rs334-T) and 1 normal beta allele, is prevalent in millions of people in the US, particularly in individuals of African and Hispanic ancestry. However, the association of SCT with COVID-19 is unclear.

Objective

To assess the association of SCT with the prepandemic health conditions in participants of the Million Veteran Program (MVP) and to assess the severity and sequelae of COVID-19.

Design, Setting, and Participants

COVID-19 clinical data include 2729 persons with SCT, of whom 353 had COVID-19, and 129 848 SCT-negative individuals, of whom 13 488 had COVID-19. Associations between SCT and COVID-19 outcomes were examined using firth regression. Analyses were performed by ancestry and adjusted for sex, age, age squared, and ancestral principal components to account for population stratification. Data for the study were collected between March 2020 and February 2021.

Exposures

The hemoglobin beta S (HbS) allele (rs334-T).

Main Outcomes and Measures

This study evaluated 4 COVID-19 outcomes derived from the World Health Organization severity scale and phenotypes derived from International Classification of Diseases codes in the electronic health records.

Results

Of the 132 577 MVP participants with COVID-19 data, mean (SD) age at the index date was 64.8 (13.1) years. Sickle cell trait was present in 7.8% of individuals of African ancestry and associated with a history of chronic kidney disease, diabetic kidney disease, hypertensive kidney disease, pulmonary embolism, and cerebrovascular disease. Among the 4 clinical outcomes of COVID-19, SCT was associated with an increased COVID-19 mortality in individuals of African ancestry (n = 3749; odds ratio, 1.77; 95% CI, 1.13 to 2.77; P = .01). In the 60 days following COVID-19, SCT was associated with an increased incidence of acute kidney failure. A counterfactual mediation framework estimated that on average, 20.7% (95% CI, -3.8% to 56.0%) of the total effect of SCT on COVID-19 fatalities was due to acute kidney failure.

Conclusions and Relevance

In this genetic association study, SCT was associated with preexisting kidney comorbidities, increased COVID-19 mortality, and kidney morbidity.

Hyperuricemia and Associated Factors in Children with Chronic Kidney Disease: A Cross-Sectional Study

Background: Hyperuricemia is increasingly recognized as a risk factor for chronic kidney disease (CKD) just in adults. The purpose of this study was to investigate the clinical characteristics of hyperuricemia and its associated factors in Chinese children with CKD at a single center. Methods: A cross-sectional study of 170 CKD children collected from the Department of Nephrology, The Zhejiang University Children’s Hospital was conducted. The clinical data, including anthropometric data, blood pressure measurements, and biochemical parameters, were recorded and analyzed retrospectively. The factors associated with hyperuricemia in CKD children were evaluated by Pearson and Spearman correlation analysis and multiple logistic regression analysis. Results: The mean age was 9.79 ± 4.10 years, and 72 (42.35%) were girls. Higher blood urea nitrogen (BUN), serum creatinine, cystatin C, D-dimer, lower hemoglobin, albumin, and estimated glomerular filtration rate (eGFR) were significantly associated with higher serum uric acid (SUA). In multiple logistic regression analysis, anemia and higher BUN were both positively associated factors, whereas eGFR ≥ 90 mL/min/1.73 m² was a negatively associated factor for subjects with SUA ≥ 390 µmol/L (6.5 mg/dL). Conclusions: SUA was significantly associated with kidney risk factors in CKD children. Monitoring and controlling SUA, Hb, BUN, and Scr levels in CKD children may help to prevent the progression of CKD.

Edible mushroom consumption and incident hyperuricemia: results from the TCLSIH cohort study

Background: Basic studies have found that xanthine oxidase inhibitors extracted from mushrooms have inhibitory effects on hyperuricemia. However, the association between mushroom consumption and hyperuricemia is unknown in humans. Objective: We therefore designed a large-scale cohort study to examine whether mushroom consumption is a protective factor for developing hyperuricemia in adults. Methods: This prospective cohort study investigated 19 830 participants (mean age: 39.4 years; and 9906 [50.0%] men) who were free of hyperuricemia, cardiovascular disease, and cancer at the baseline. Mushroom consumption was measured at the baseline using a validated food frequency questionnaire. Hyperuricemia is defined as serum uric acid levels >420 μmol L^-1 in men and >350 μmol L^-1 in women. Cox proportional hazards regression models were used to examine the association of mushroom consumption with incident hyperuricemia. Restricted cubic spline regression was used to estimate the dose-response relationship between mushroom consumption and risk of hyperuricemia. Results: A total of 4260 first incident cases of hyperuricemia occurred during 61 421 person-years of follow-up (median follow-up of 4.2 years). After adjusting for demographic characteristics, lifestyle factors, dietary intake, and inflammatory markers, the multivariable hazard ratios (95% confidence intervals) for incident hyperuricemia were 1.00(reference) for <1.76 g per 1000 kcal per day, 0.93(0.86, 1.01) for 1.76-2.84 g per 1000 kcal per day, 0.93(0.85, 1.01) for 2.85-5.52 g per 1000 kcal per day, and 0.88 (0.80, 0.96) for >5.52 g per 1000 kcal per day, respectively (P for trend = 0.007). Conclusions: This population-based prospective cohort study has firstly demonstrated that higher mushroom consumption is significantly associated with lower incidence of hyperuricemia among general adults.

Dietary patterns and risk for hyperuricemia in the general population: Results from the TCLSIH cohort study

OBJECTIVE

Prospective cohort studies linking dietary patterns and hyperuricemia (HUA) are limited, especially in Asian populations. The aim of this study was to prospectively investigate the association between various dietary patterns and risk for HUA in a general adult population.

METHOD

We used data from the TCLSIH (Tianjin Chronic Low-grade Systemic Inflammation and Health) cohort study of 20 766 men and women who were free from HUA, cancer, and cardiovascular disease at baseline. Dietary patterns at baseline were identified with factor analysis based on responses to a validated 81-item food frequency questionnaire. HUA was defined as serum uric acid levels >420 μmol/L in men and >350 μmol/L in women. Cox proportional hazards regression models were used to examine the association of dietary patterns with incident HUA.

RESULTS

In all, 4389 first incident cases of HUA occurred during 73 822 person-years of follow-up (median follow-up of 4.2 y). Three main dietary patterns were extracted. They were the vegetable, sweet food, and animal food patterns. After adjusting for demographic characteristics, lifestyle factors, other dietary pattern scores, and inflammatory markers, comparing the highest with the lowest quartiles of dietary pattern scores, the multivariable hazard ratios (95% confidence interval) of HUA were 0.79 (0.72-0.87; P_trend < 0.0001) for the vegetable pattern, 1.22 (1.12-1.33; P_trend < 0.0001) for the sweet food pattern, and 1.24 (1.13-1.37; P_trend < 0.0001) for the animal food pattern.

CONCLUSIONS

Dietary patterns rich in animal or sweet foods were positively associated with a higher risk for HUA, whereas the vegetable pattern was negatively associated.

Hyperuricemia, Elevated Body Mass Index, Female Sex, and Albuminuria Increase the Probability of Elevated High-Sensitivity C-Reactive Protein: Results From the National Health and Nutrition Examination Survey 2015-2018

Importance: High uric acid (UA) is hypothesized to worsen kidney and cardiovascular disease morbidity via activation of systemic inflammation. Clinical trials of UA modification report reduction of the inflammatory marker high sensitivity C-reactive protein (hs-CRP) as an outcome measure, but studies have not demonstrated that hyperuricemia independently increases hs-CRP when adjusted for important confounders such as body mass index (BMI), sex, and age. Objective: To identify clinical risk factors for elevated hs-CRP, including but not limited to hyperuricemia, through a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) 2015-2018. Results: In the final multivariate logistic regression model, the exposure with the strongest effect on the odds of elevated hs-CRP was BMI in the fourth quartile, OR = 13.1 (95% CI 6.25-27.42), followed by female sex (OR = 4.9, 95% CI 2.92-8.34), hyperuricemia (OR = 2.2, 95% CI 1.36-3.45), urine albumin creatinine ratio (ACR; OR = 1.5, 95% CI 1.09-2.18), poor overall health (OR = 1.4, 95% CI 1.18-1.58), and interactions between hyperuricemia and sex (OR = 1.4, 95% CI 1.05-1.83), and between BMI and sex (OR = 1.2, 95% CI 1.03-1.47). Notably, chronic kidney disease (CKD) and CKD surrogates were not associated with hs-CRP despite urine ACR maintaining a significant independent effect. Conclusions: In this national population-based study, we demonstrated that hyperuricemia significantly increases the odds of elevated hs-CRP, independent from BMI, female sex, urine ACR, and overall health status. Further study is recommended to better understand the sex difference in this association and the role of albuminuria, but not CKD, in systemic inflammation.