Cardiovascular and renal effects of hyperuricaemia and gout

Medium- and Long-Term Effects of Dapagliflozin on Serum Uric Acid Level in Patients with Type 2 Diabetes: A Real-World Study

We aimed to explore the medium- and long-term (≥12 weeks) effects of dapagliflozin on serum uric acid (SUA) level in patients with type 2 diabetes mellitus (T2DM) in the real world study and to explore the influencing factors of dapagliflozin on reducing SUA level. This observational, prospective cohort study was based on the real world. There were 77 patients included in this study. They were divided into two groups. Patients in treatment group (n = 38) were treated as dapagliflozin 10 mg/d combined with therapy of routine glucose-lowering drugs (GLDs), and patients in the control group (n = 39) were treated with their routine GLDs. All measurements of physical examinations, blood, and urine samples, including age, sex, weight, height, systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), and SUA, were collected at baseline for all patients in these two groups and repeated after 12, 24, and 48 weeks of therapy. We compared the changes of metabolic indicators including SUA in these two groups to evaluate the effects of dapagliflozin and analyzed its influencing factors. In the dapagliflozin group, mean SUA levels significantly decreased from 334.2 ± 99.1 μmol/L at baseline to 301.9 ± 73.2 μmol/L after 12 weeks therapy (t = 2.378, p = 0.023). There was no significant statistical difference of SUA levels after 24 weeks treatment of dapagliflozin compared with 12-week and 48-week treatment with dapagliflozin (p > 0.05). We found that baseline SUA had a significant impact on the effect of dapagliflozin on reducing SUA (OR 1.014, 95%CI 1.003−1.025, p = 0.014) by logistic regression analysis. Receiver operating characteristic (ROC) curve showed that T2DM patients with SUA level ≥ 314.5 μmol/L had relative accuracy in recognizing the good effects of dapagliflozin on reducing SUA (sensitivity 76.9%, specificity 76.2%). Combination therapy of dapagliflozin with routine blood-glucose-lowering drugs in T2DM patients showed the significant and sustained stable effect of lowering SUA level in this real-world study.

A Phase I, Randomized, Single-Ascending-Dose, Multiple-Dose, and Food-Effect Trial of the Safety, Efficacy, and Pharmacokinetics of Topiroxostat in Healthy Chinese Participants

Background: As the structure of the human diet changes, the prevalence of hyperuricemia is increasing each year. Hyperuricemia and its comorbidities, such as gout, severely affect quality of life. Moreover, hyperuricemia causes renal impairment and is associated with chronic kidney disease. Topiroxostat, a selective xanthine oxidoreductase inhibitor, has been approved to treat hyperuricemia or gout in Japan. Topiroxostat has shown good tolerance and efficacy in the Japanese population. However, its pharmacokinetic (PK) characteristics, efficacy, and safety in the Chinese population remains unknown.Objective: This trial evaluated the PK profile, safety, efficacy, and food effects of Topiroxostat in healthy Chinese participants.Methods: The major endpoint was determination of the PK profile of Topiroxostat. Topiroxostat concentrations were detected with LC-MS/MS. PK parameters were calculated in Phoenix WinNonlin 8.1. Minor endpoints were safety and efficacy assessments. Assessment of adverse events and safety was performed by clinicians. Plasma uric acid concentration (ΔECmax and ΔAUEC) was determined as the pharmacodynamic index. This study consisted of three arms: single ascending dose (20, 40, and 80 mg, N = 10), multiple dose (80 mg BID, 7 days, N = 10), and food effects (40 mg single dose, fasting-fed cross-over design, N = 10).Results: In the single-ascending-dose arm, Topiroxostat showed rapid absorption and excretion, with Tmax <1.6 h and T1/2 2.49–3.72 h. Additionally, Topiroxostat showed a wide distribution, on the basis of moderate Vz/F (242.8–336.36 L). The main PK parameters Cmax, AUC0-t, and AUC0-C showed a linear relationship with dose (R2 = 0.5146, 0.8416, 0.8386, respectively). In the multiple-dose arm, no significant differences were observed in Cmin on days 3–6 (P = 0.265). No serious adverse events were observed. Regarding efficacy, plasma uric acid levels were controlled to low levels during multiple-dose administration. In the food-effects arm, the fed group showed a lower Cmax than the fasting group (316.00 ± 135.81 vs. 478.40 ± 175.42 ng/mL, P = 0.033) but demonstrated better efficacy (ΔECmax, P < 0.001; ΔAUEC, P < 0.001).Conclusions: Topiroxostat showed rapid absorption and a broad distribution in healthy Chinese adults. Additionally, it showed good safety and tolerance in the Chinese population. Moreover, the pharmacodynamic profile indicated that post cibum administration increased the efficacy of Topiroxostat.

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.

Crystal arthritides - gout and calcium pyrophosphate arthritis : Part 2: clinical features, diagnosis and differential diagnostics

Gout develops in four stages beginning with an asymptomatic increase in blood levels of uric acid. An acute gout attack is an expression of an underlying inflammatory process, which in the course of time is self-limiting. Without therapy monosodium urate crystals remain in the synovial fluid and synovial membrane and trigger more acute attacks. In the course of the disease monosodium urate crystals form deposits (tophi) leading in severe forms to irreversible joint deformities with loss of functionality. In 20% of cases gout leads to involvement of the kidneys. Overproduction of uric acid can cause nephrolithiasis. These stones can be composed of uric acid or calcium phosphate. Another form of kidney disease caused by gout is uric acid nephropathy. This is a form of abacterial chronic inflammatory response with deposition of sodium urate crystals in the medullary interstitium. Acute obstructive nephropathy is relatively rare and characterized by renal failure due to uric acid precipitation in the tubules because of rapid cell lysis that occurs, for example, with chemotherapy. There is a causal interdependence between the occurrence of hyperuricemia and hypertension. Uric acid activates the renin-angiotensin-aldosterone (RAA) system and inhibits nitric oxide (NO) with the possible consequence of a rise in systemic vascular resistance or arteriolar vasculopathy; however, uric acid is also an apparently independent risk factor for atherosclerosis. In contrast to young patients, the diagnosis of an acute gout attack in the elderly can be a challenge for the physician. Polyarticular manifestations and obscure symptoms can make it difficult to differentiate it from rheumatoid arthritis and calcium pyrophosphate deposition disease (CPPD). Aspiration of synovial fluid with visualization of urate crystals using compensated polarized light microscopy is the gold standard for diagnosis of acute gout. Moreover, analysis of synovial fluid enables a distinction from septic arthritis by Gram staining and bacterial culture. Soft tissue ultrasonography is useful to detect affected synovial tissue and monosodium urate crystals within the synovial fluid. Involvement of bone occurs relatively late in the disease so that x‑ray images are not useful in the early stages but might be helpful in differential diagnostics. Dual energy computed tomography (CT) and magnetic resonance imaging (MRI) can be used for certain indications.

Effects of febuxostat on insulin resistance and expression of high-sensitivity C-reactive protein in patients with primary gout

We aimed to investigate the effects of febuxostat on IR and the expression of high-sensitivity C-reactive protein (hs-CRP) in patients with primary gout. Forty-two cases of primary gout patients without uric acid-lowering therapy were included in this study. After a physical examination, 20 age- and sex-matched patients were included as normal controls. The levels of fasting insulin (INS), fasting blood glucose (FBG), and hs-CRP were determined. IR was assessed using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). Gout patients had higher levels of UA, INS, HOMA-IR, and hs-CRP than normal controls (P < 0.05). After 4-, 12-, and 24-week febuxostat treatments, UA and hs-CRP concentrations were significantly lower than baseline (P < 0.05). INS and HOM-IR decreased slightly after a 4-week treatment with febuxostat but declined significantly after 12 and 24 weeks of treatment. Importantly, hs-CRP values positively correlated with those of HOMA-IR (r = 0.353, P = 0.018) and INS (r = 0.426, P = 0.034). Our findings confirm that IR exists in gout patients and implicate that febuxostat can effectively control the level of serum UA and increase insulin sensitivity in primary gout patients.