Urate Reduction and Renal Preservation: What Is the Evidence?

Effect of febuxostat on renal function in patients from South China with CKD3 diabetic nephropathy

OBJECTIVE

To investigate the efficacy and safety of febuxostat on renal function in CKD stage 3 diabetic nephropathy patients.

METHODS

Patients in our hospital with chronic kidney disease (CKD) stage 3 diabetic nephropathy (DN) complicated by high serum uric acid (360 µmol/L) were recruited. Patients were then divided into treatment group and control group according to the random number table method. All the patients received low purine diet, renin-angiotensin-aldosterone system (RAAS) inhibitors, and adequate routine hypoglycemic treatment. Febuxostat was employed only in the treatment group. The levels of blood uric acid (sUA), serum creatinine (Scr), cystatin C (cys-c), eGFR, 24-hour urine protein quantification, albuminuria, and creatinine ratio (ACR) were evaluated in all patients before and after treatment at 4, 8, 12, and 24 week.

RESULTS

No difference was found before treatment between the two groups. After treatment at 4, 8, 12, and 24 week, the levels of sUA, SCr, cys-c, and eGFR between the two groups were significant different (P<0.05). There was no difference in 24-hour urine protein quantification, albuminuria, and creatinine ratio between two groups before treatment, and significant differences were observed after treatment. Fifty percent of patients from the treatment group achieved the treatment goal with 20 mg febuxostat at 4 weeks. Tubular markers were also decreased with the treatment.

CONCLUSIONS

Febuxostat can reduce uric acid and improve renal function effectively in patients with CKD stage 3 diabetic nephropathy, while being well tolerated. However, the conclusion is still uncertain due to the short term of the study.

Relationships of Hyperhomocysteinemia and Hyperuricemia With Metabolic Syndrome and Renal Function in Chinese Centenarians

As the first time worldwide, this study aimed to investigate the relationships of hyperhomocysteinemia and hyperuricemia with metabolic syndrome (MetS) and renal function in Chinese centenarians. The China Hainan Centenarian Cohort Study was performed in 18 cities and counties of the Hainan Province. Home interview, physical examination, and blood analysis were performed on 808 centenarians following standard procedures. All centenarians had a median age of 102 (100-115) years. Prevalence of hyperhomocysteinemia and hyperuricemia was 91.6% (740 centenarians) and 28.5% (230 centenarians), respectively. The MetS was present in 117 centenarians (14.5%). In simple correlation analyses, hyperhomocysteinemia and hyperuricemia were significantly correlated with MetS and glomerular filtration rate (GFR) < 60 ml/min/1.73 m² (P < 0.05 for all). Serum homocysteine levels were significantly correlated with GFR, waist circumference (WC), and triglyceride levels, while serum uric acid levels were significantly correlated with these variables plus high-density lipoprotein cholesterol (HDL-C) levels (P < 0.05 for all). In logistic regression analyses, hyperhomocysteinemia and hyperuricemia were significantly associated with MetS and GFR < 60 ml/min/1.73 m² (P < 0.05 for all). In linear regression analyses, serum homocysteine levels were significantly associated with GFR, WC, and triglyceride, while serum uric acid levels were significantly associated with these variables plus HDL-C (P < 0.05 for all). Both hyperhomocysteinemia and hyperuricemia had important relationships with MetS and renal function in Chinese centenarians. Hyperuricemia and hyperhomocysteinemia that could help identify, while also affecting, the development of MetS and renal function may unfold complex relationships between MetS, renal function, and cardiovascular risk and provide effective prevention strategies for these conditions.

Hiperuricemia assintomática - tratar ou não tratar? - Uma revisão baseada na evidência

Introdução: A avaliação dos níveis séricos de ácido úrico é realizada com frequência nos Cuidados de Saúde Primários, porém sem evidência científica que a justifique. A abordagem terapêutica subsequente constitui frequentemente um desafio clínico, particularmente no caso da hiperuricemia assintomática (HA). O objetivo desta revisão foi rever a evidência sobre a pertinência do tratamento da HA. Métodos: Pesquisa de normas de orientação clínica (NOC), revisões sistemáticas (RS), meta-análises (MA) e estudos originais (EO) no Medline e outros sítios de Medicina Baseada na Evidência, publicados desde abril de 2012 até abril de 2016, em inglês, espanhol e português. Termos MeSH: “hyperuricemia” e ”asymptomatic conditions”. Resultados: Cinco estudos cumpriam os critérios de inclusão: uma MA, três RS e um EO. A MA e o EO recomendam o tratamento da HA, para a prevenção da disfunção renal e para prevenção de eventos cardiovasculares (CV), respetivamente. Duas RS não recomendam o tratamento da HA e uma recomenda uma decisão individualizada para valores de uricemia acima de 9mg/dL, particularmente para a prevenção da gota. Conclusões: A evidência científica disponível é escassa, com limitações, e controversa no que diz respeito à instituição de tratamento farmacológico. O significado clínico da HA e sua relação causal com ocorrência de crises agudas de gota, disfunção renal e doença cardiovascular ainda são incertos. Não existe evidência científica que justifique o tratamento farmacológico da HA em doentes assintomáticos (SOR B). São, por isso, necessários mais estudos, metodologicamente robustos e orientados para o paciente.