This study aimed to investigate the contribution of renal dysfunction to enhanced hyperuricemia prevalence in older people. A cohort of 13,288 Chinese people aged between 40 and 95 years were recruited from January to May 2019. Serum uric acid concentration and estimated glomerular filtration rate [eGFR] were measured. The associations between age or eGFR and serum uric acid or hyperuricemia were analyzed using linear or binary logistic regression adjusting for risk factors. Uric acid concentration and prevalence of hyperuricemia were greater in older participants. Adjustment for reduced renal function (eGFR < 60 mL/min/1.73 m²) eliminated the associations between older age and higher uric acid concentration and between older age and higher prevalence of hyperuricemia diagnosis, whereas adjustment for other risk factors did not change those associations. Lower eGFR was associated with higher uric acid concentration both before (β = − 0.296, P < 0.001) and after adjustment for age (β = − 0.313, P < 0.001). Reduced renal function was associated with hyperuricemia diagnosis both before (odds ratio, OR, 3.64; 95% CI 3.10–4.28; P < 0.001) and after adjustment for age (adjusted OR, 3.82; 95% CI 3.22–4.54; P < 0.001). Mean serum uric acid and prevalence of hyperuricemia were higher in people with eGFR < 60 mL/min/1.73 m² than those with eGFR ≥ 60 mL/min/1.73 m². The prevalence of reduced renal function increased with older age (P < 0.001). This study suggests that reduced renal function can explain the increased uric acid levels and hyperuricemia diagnoses in older people.

High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants. A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricase-peroxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7 mg/dL in men and >6 mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis. The prevalence of hypertension and HUA increased with age (P < .001). Hypertension was more common in participants that had HUA than in those that did not (38.95% vs 30.16%, P = .02). Higher sUA was significantly associated with higher SBP and DBP in the 41- to 50-year-old participants (SBP, β = 0.35, P < .001; DBP, β = .29, P < .001; after adjustment for age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217–1.668, P < .001). There was no association between sUA concentration and SBP and DBP in the other age groups. In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension.

The specific mechanisms of doxorubicin (Dox)‑induced cardiotoxicity (DIC) remain unclear. In the present study, H9c2 cardiomyocytes were treated with Dox, and it was revealed that DEAD‑box RNA helicase 3 X‑linked (DDX3X), mitochondrial antiviral signaling (MAVS) and stress granules (SGs) were present at lower levels in the treated H9c2 cardiomyocytes compared with those in the control cells. The present study further investigated the mechanisms through which DIC occurs. Pretreatment with arsenite, which pharmacologically accelerates SGs, alleviated the myocardial injury caused by Dox. By contrast, anisomycin, an SG inhibitor, increased cardiomyocyte apoptosis induced by Dox. In addition, both DDX3X knockdown and pretreatment with RK‑33 (a DDX3X pharmacological inhibitor) decreased SG expression, whereas DDX3X overexpression promoted SG generation. These results indicated that DDX3X mitigated DIC through the regulation of SGs. In addition, MAVS knockdown inhibited SG assembly and reduced the expression of the anti‑apoptotic inhibitor Bcl2, and MAVS was influenced by DDX3X, thereby serving as a connector between DDX3X and SGs. The results from western blotting, reverse transcription‑quantitative PCR, immunofluorescence and flow cytometry analysis demonstrated that DDX3X, MAVS, and SGs may serve as key protective factors in DIC.