Hyperuricemia and diabetes mellitus when occurred together have higher risks than alone on all-cause mortality and end-stage renal disease in patients with chronic kidney disease

Introduction

Hyperuricemia and diabetes mellitus (DM) are associated with increased mortality risk in patients with chronic kidney disease (CKD). Here we aimed to evaluate the independent and joint risks of these two conditions on mortality and end stage kidney disease (ESKD) in CKD-patients.

Methods

This retrospective cohort study enrolled 4380 outpatients (with CKD stage 3–5) with mortality and ESKD linkage during a 7-year period (from 2007 to 2013). All-causes mortality and ESKD risks were analyzed by multivariable-adjusted Cox proportional hazards models (adjusted for age, sex, smoke, previous coronary arterial disease, blood pressure, and medications for hyperlipidemia, hyperuricemia and renin–angiotensin system inhibitors).

Results

Overall, 40.5% of participants had DM and 66.4% had hyperuricemia. In total, 356 deaths and 932 ESKD events occurred during the 7 years follow-up. With the multivariate analysis, increased risks for all-cause mortality were: hyperuricemia alone, HR = 1.48 (1–2.19); DM alone, and HR = 1.52 (1.02–2.46); DM and hyperuricemia together, HR = 2.12 (1.41–3.19). Similar risks for ESKD were: hyperuricemia alone, HR = 1.34 (1.03–1.73); DM alone, HR = 1.59 (1.15–2.2); DM and hyperuricemia together, HR = 2.46 (1.87–3.22).

Conclusions

DM and hyperuricemia are strongly associated with higher all-cause mortality and ESKD risk in patients with CKD stage 3–5. Hyperuricemia is similar to DM in terms of risk for all-cause mortality and ESKD. DM and hyperuricemia when occurred together further increase both risks of all-cause mortality and ESKD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02755-1.

Vitamin D3 potentiates the renoprotective effects of vildagliptin in a rat model of fructose/salt-induced insulin resistance

Insulin resistance (IR) seemingly plays a role in chronic kidney disease (CKD). The present study has elucidated the crucial interplay of oxidative stress, inflammatory, apoptotic and profibrotic signaling pathways, linking IR to CKD. The study aimed at investigating the pleiotropic nephroprotective effects of either vildagliptin or vitamin D3 in a fructose/salt-induced IR rat model, highlighting the potential molecular mechanisms underlying their action. Another interesting target was to evaluate the potential capacity of vitamin D3 to potentiate the nephroprotective effects of vildagliptin. Indeed, a state of impaired fasting glucose, IR and compensatory hyperinsulinemia, constellating with significant weight gain, atherogenic dyslipidemia and hyperuricemia was established 6 weeks after fructose/salt consumption. IR rats were then treated orally with vildagliptin (10 mg/kg/day), vitamin D3 (10 µg/kg/day) or their combination for a further 6 weeks. By the end of the 12^th week, untreated IR rats displayed significantly declined renal function with parallel interwined renal oxidative stress, inflammatory, apoptotic and profibrotic changes, renal histopathological damages and markedly enhanced collagen fiber deposition. Vildagliptin and vitamin D3 reversed hyperuricemia and exerted a plethora of renal anti-oxidant, anti-inflammatory, anti-apoptotic and anti-fibrotic effects. Our study has introduced a new insight into the role of dipeptidyl peptidase-4 inhibition and silent information regulator 1/5'adenosine monophosphate-activated protein kinase activation in the nephroprotective effects of either agent, elucidating their possible crosstalk with renin angiotensin aldosterone system downregulation. Considering the superadditive renoprotective effects evoked by the combination, vitamin D3 is worth being further investigated as an additional therapeutic agent for preventing IR-induced nephropathy.

Effects of Alismatis Rhizoma and Rhizoma Smilacis Glabrae Decoction on Hyperuricemia in Rats

The combination of Alismatis Rhizoma (AR) and Rhizoma Smilacis Glabrae (RSG), as Chinese herb medicine, has been used for their uric acid-lowering effect. However, the effects and mechanism of the combination of the two medicines have not been fully reported. Therefore, to explore the effects of AR-RSG combination decoction on the treatment of chronic hyperuricemia (HUA) in rats as well as the underlying mechanisms, in this study, at the first stage, a long-term HUA rats model was established by gavage of oteracil potassium plus adenine; allopurinol was used as the positive control, and the uric acid-lowering effects of AR or RSG decoction alone with low and high dose were evaluated, respectively. Serum uric acid (UA) and xanthine oxidase (XOD) were determined mainly, and pathological analysis of the kidney and liver was carried out after sacrifice of the animals. And then, at the second stage, four dose groups of AR-RSG combination treatment were investigated in HUA rats. In addition to the indicators measured at the first stage, the expression of urate anion exchanger 1 (URAT1) in rat kidney was determined by immunohistochemistry. We discovered that the UA levels of the model group in both stages were significantly and steadily higher than those of control groups. AR and RSG alone or in combination possess ability to decrease serum UA level of HUA rats, with effects more marked in the combination groups. The uric acid-lowering mechanism of AR-RSG combination may be related to its inhibiting activity of XOD, improving kidney damage and downregulating the expression of URAT1 in kidney.

Effect of allopurinol on the glomerular filtration rate of children with chronic kidney disease

BACKGROUND

Hyperuricemia is a leading risk factor for the development of chronic kidney disease (CKD). We hypothesized that lowering serum uric acid (SUA) with allopurinol in hyperuricemic children with CKD may reduce the risk of CKD progression.

METHODS

A total of 70 children, aged 3-15 years, with elevated serum uric acid level (SUA) > 5.5 mg/dL and CKD stages 1-3 were prospectively randomized to receive allopurinol 5 mg/kg/day (study group, n = 38) or no treatment (control group, n = 32) for 4 months. The primary and secondary outcomes were changes in estimated glomerular filtration rate (eGFR) (> 10 mL/min/1.73m²) and the SUA (> 1.0 mg/dL) from baseline values, respectively.

RESULTS

Baseline age, gender, blood pressure (BP), body mass index (BMI), SUA, high-sensitive C-reactive protein (hsCRP), and eGFR were similar in allopurinol and control subjects. Allopurinol treatment resulted in a decrease in SUA, a decrease in systolic and diastolic BP, a decrease in hsCRP, and an increase in eGFR compared with the baseline values (p < 0.05 for all). No significant difference was observed in the control hyperuricemic subjects. In multiple regression analysis after incorporating variables (age, gender, BMI, systolic and diastolic BP, CRP, and SUA), eGFR was independently related to SUA both before and after treatments (p = 0.03 vs. p = 0.02, respectively). All patients in the study group tolerated allopurinol, and there were no adverse reactions observed by physical examination or reported by patients.

CONCLUSION

Urate-lowering therapy with allopurinol, over a 4-month period, can improve renal function in children with CKD stages 1-3.

Spinal Gout Without Spinal Symptom in a Junior School Student: A Case Report

STUDY DESIGN

Case report.

OBJECTIVE

We report a case of a 16-year-old boy with intermittent and migratory polyarthralgia, who made a diagnostic dilemma.

SUMMARY OF BACKGROUND DATA

Spinal involvement without spinal symptom in gout seems to be rare. However, the relationship of spinal gout to symptoms is poorly understood.

METHODS

Description of the case report.

RESULTS

Laboratory findings cannot explain his symptoms; however, a computed tomography of the pelvis revealed the presence of space-occupying lesion involving the left side of spine at L5-S1 level, and the later biopsy revealed that was a urate crystal, which help us make the diagnosis of spinal gout.

CONCLUSION

Gout can be a cunning disease which has various manifestations, and spinal involvement can be asymptomatic.

LEVEL OF EVIDENCE

5.

The association between elevated serum uric acid level and an increased risk of renal function decline in a health checkup cohort in China

PURPOSE

To investigate whether an elevated serum uric acid (SUA) level is an independent risk factor for rapid decline in renal function or new-onset chronic kidney disease (CKD) in a Chinese health checkup population.

METHODS

A cohort study of 6495 Chinese individuals who underwent health checkups with normal estimated glomerular filtration rate (eGFR) at baseline was carried out from May 2011 to April 2016. Examinations included a questionnaire, physical measurements, and blood sampling. The gender-specific quartiles of blood uric acid were used to present baseline descriptive data. Rapid decline of renal function was defined as eGFR loss of > 3 mL/min/1.73 m²/year. New-onset CKD was defined as follow-up eGFR < 60 mL/min/1.73 m² or positive proteinuria. Multivariable logistic regression was used to assess the relationship between serum uric acid and the following outcomes: rapid decline of renal function, incident CKD, and combined renal outcomes.

RESULTS

During mean follow-up of 52.8 months, 1608 (24.8%) individuals reached combined renal events. Rapid decline in renal function developed in 1506 (23.2%) individuals, and incident CKD was documented in 372 (5.7%) individuals. In a multivariate model adjusted for age, BMI, diabetes, hypertension, alcohol drinking, SBP, total cholesterol, and eGFR, the odds ratio for rapid decline of renal function increased across quartiles of serum uric acid level, reaching a 1.32 (95% CI 1.02-2.97) for the top quartile compared to the lowest quartile (P for trend < 0.001). Meanwhile, higher SUA was also associated with incident CKD in all models. Furthermore, an increased risk of reaching renal outcomes across increasing quartiles of SUA levels appeared to be similar among subgroups stratified according to age, eGFR, and SBP (P < 0.05 in all).

CONCLUSIONS

These findings suggest that higher SUA may predict progressive renal damage and dysfunction in a health checkup population in China.

Elevated Serum Uric Acid Level Predicts Rapid Decline in Kidney Function

BACKGROUND

While elevated serum uric acid level (SUA) is a recognized risk factor for chronic kidney disease, it remains unclear whether change in SUA is independently associated with change in estimated glomerular filtration rate (eGFR) over time. Accordingly, we examined the longitudinal associations between change in SUA and change in eGFR over 5 years in a general Japanese population.

METHODS

This was a large, single-center, retrospective 5-year cohort study at St. Luke's International Hospital, Tokyo, Japan, between 2004 and 2009. We included 13,070 subjects (30-85 years) in our analyses whose data were available between 2004 and 2009. Of those, we excluded 492 subjects with eGFR <60 mL/min/1.73 m2 at baseline. In addition to examining the entire cohort (n = 12,578), we stratified our analyses by baseline eGFR groups: 60-90, 90-120, and ≥120 mL/min/1.73 m2. Linear and logistic regressions models were applied to examine the relationships between baseline and change in SUA, change in eGFR, and rapid eGFR decline (defined as the highest quartile of change in eGFR), adjusted for age, gender, body mass index, abdominal circumference, hypertension, dyslipidemia, and diabetes mellitus.

RESULTS

After multivariable adjustments including baseline eGFR, 1 mg/dL increase in baseline SUA was associated with greater odds of developing rapid eGFR decline (OR 1.27, 95% CI 1.17-1.38), and 1 mg/dL increase in SUA over 5 years was associated with 3.77-fold greater odds of rapid eGFR decline (OR 3.77, 95% CI 3.35-4.26).

CONCLUSIONS

Elevated baseline SUA and increasing SUA over time were independent risk factors for rapid eGFR decline over 5 years.