Gout and risk of non-alcoholic fatty liver disease

Effects of plant natural products on metabolic-associated fatty liver disease and the underlying mechanisms: a narrative review with a focus on the modulation of the gut microbiota

Metabolic-associated fatty liver disease (MAFLD) is a chronic liver disease characterized by the excessive accumulation of fat in hepatocytes. However, due to the complex pathogenesis of MAFLD, there are no officially approved drugs for treatment. Therefore, there is an urgent need to find safe and effective anti-MAFLD drugs. Recently, the relationship between the gut microbiota and MAFLD has been widely recognized, and treating MAFLD by regulating the gut microbiota may be a new therapeutic strategy. Natural products, especially plant natural products, have attracted much attention in the treatment of MAFLD due to their multiple targets and pathways and few side effects. Moreover, the structure and function of the gut microbiota can be influenced by exposure to plant natural products. However, the effects of plant natural products on MAFLD through targeting of the gut microbiota and the underlying mechanisms are poorly understood. Based on the above information and to address the potential therapeutic role of plant natural products in MAFLD, we systematically summarize the effects and mechanisms of action of plant natural products in the prevention and treatment of MAFLD through targeting of the gut microbiota. This narrative review provides feasible ideas for further exploration of safer and more effective natural drugs for the prevention and treatment of MAFLD.

Mechanisms and rationale for uricase use in patients with gout

Xanthine oxidase inhibitors such as allopurinol and febuxostat have been the mainstay urate-lowering therapy (ULT) for treating hyperuricaemia in patients with gout. However, not all patients receiving oral ULT achieve the target serum urate level, in part because some patients cannot tolerate, or have actual or misconceived contraindications to, their use, mainly due to comorbidities. ULT dosage is also limited by formularies and clinical inertia. This failure to sufficiently lower serum urate levels can lead to difficult-to-treat or uncontrolled gout, usually due to poorly managed and/or under-treated gout. In species other than humans, uricase (urate oxidase) converts urate to allantoin, which is more soluble in urine than uric acid. Exogenic uricases are an exciting therapeutic option for patients with gout. They can be viewed as enzyme replacement therapy. Uricases are being used to treat uncontrolled gout, and can achieve rapid reduction of hyperuricaemia, dramatic resolution of tophi, decreased chronic joint pain and improved quality of life. Availability, cost and uricase immunogenicity have limited their use. Uricases could become a leading choice in severe and difficult-to-treat gout as induction and/or debulking therapy (that is, for lowering of the urate pool) to be followed by chronic oral ULT. This Review summarizes the evidence regarding available uricases and those in the pipeline, their debulking effect and their outcomes related to gout and beyond.

Association Between Serum Uric Acid and Non-Alcoholic Fatty Liver Disease: An Updated Systematic Review and Meta-Analysis

Objective

Recent epidemiological evidence shows that there is an association between serum uric acid (SUA) levels and nonalcoholic fatty liver disease (NAFLD). The purpose of this meta-analysis is to summarize all available evidence and assess the associations between SUA levels and NAFLD.

Methods

Using two databases, Web of Science and PubMed, observational studies were applied from the establishment of the databases to June 2022. We used a random effect model to construct the pooled odds ratio (OR) and 95% confidence interval (CI) to appraise the association between SUA levels and NAFLD. The Begg's test was conducted to appraise publication bias.

Results

A total of 50 studies were included, involving 2,079,710 participants (719,013 NAFLD patients). The prevalence and incidence rates (95% CIs) of NAFLD in the patients with hyperuricemia were 65% (57-73%) and 31% (20-41%), respectively. Compared to participants with lower levels of SUA, the pooled OR (95% CI) of NAFLD in those with higher levels of SUA was 1.88 (95% CI: 1.76-2.00). In the subgroup analyses, we found that SUA levels were positively associated with NAFLD in all subgroups, according to study design, study quality, sample size, sex, comparison, age, or country.

Conclusion

This meta-analysis shows that increased SUA levels are positively associated with NAFLD. The results suggested that reducing SUA levels can be a potential strategy for the prevention of NAFLD.

Registration Number

PROSPERO-CRD42022358431.

Assessing the clinical utility of major indices for nonalcoholic fatty liver disease in East Asian populations

Nonalcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease. The growing prevalence of NAFLD is strongly associated with the high incidence of metabolic syndrome. NAFLD affects as much as 19% of the US population with a disproportionate impact on minority racial groups such as Asian Americans. If not promptly managed, NAFLD may progress to more feared complications. Liver indices for NAFLD screening have been proposed but were often developed using study populations with different anthropometrics than patients of East Asian descent. This review compares the accuracy of five indices for NAFLD screening in Asian cohorts. The Fatty Liver Index performed well in multiple large-scale community studies, although other indices may be more suited for specific patient cohorts. This is important, as the utilization of liver indices could accelerate screening for NAFLD for early management and to reduce liver disease-related health disparities among Asian Americans.

The risk of nonalcoholic fatty liver disease in gout patients with frequent flares: a retrospective cohort study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease that is related to high serum uric acid; however, the association between the frequency of gout flares and NAFLD risk remains unclear. This study aimed to investigate whether frequent gout flares were associated with incident NAFLD and analyze the interaction of frequency of gout flares and Adipo-IR on NAFLD in the gout Chinese population.

METHODS

A total of 350 cases of gout patients were enrolled in this retrospective cohort study. Cox proportional hazard regression analyses were performed to determine the association between frequent gout flares and NAFLD during follow-up and analyze the interaction of frequency of gout flares and Adipo-IR on NAFLD. Receiver operating curves (ROC) were plotted to explore the diagnostic value of frequent gout flares and Adipo-IR on the occurrence of NAFLD.

RESULTS

NAFLD developed in 78 participants (22.3%) during follow-up. Logistic regression showed that Adipo-IR was an independent factor associated with frequent gout flares risk. The multivariate Cox regression analysis revealed that frequent gout flares and Adipo-IR were associated with NAFLD risk (HR: 7.88, 95% CI: 2.11-29.48, p < 0.01; HR: 1.058, 95% CI: 1.01-1.2, p < 0.05). And ROC showed that both of them had a great discriminant ability to diagnose NAFLD.

CONCLUSIONS

Our data showed an independent association between the frequency of gout flares or Adipo-IR and incident NAFLD. Frequent gout flares and elevated Adipo-IR had a good predictive capability towards NAFLD development and played a synergistic role in the development of NAFLD.

KEY POINTS

• Frequent gout flares and elevated Adipo-IR had a good diagnostic capability towards NAFLD development. • Frequent gout flares and Adipo-IR played a synergistic role in the development of NAFLD.

Obese female mice do not exhibit overt hyperuricemia despite hepatic steatosis and impaired glucose tolerance

Recent reports have clearly demonstrated a tight correlation between obesity and elevated circulating uric acid levels (hyperuricemia). However, nearly all preclinical work in this area has been completed with male mice, leaving the field with a considerable gap in knowledge regarding female responses to obesity and hyperuricemia. This deficiency in sex as a biological variable extends beyond unknowns regarding uric acid (UA) to several important comorbidities associated with obesity including nonalcoholic fatty liver disease (NAFLD). To attempt to address this issue, herein we describe both phenotypic and metabolic responses to diet-induced obesity (DIO) in female mice. Six-week-old female C57BL/6J mice were fed a high-fat diet (60% calories derived from fat) for 32 weeks. The DIO female mice had significant weight gain over the course of the study, higher fasting blood glucose, impaired glucose tolerance, and elevated plasma insulin levels compared to age-matched on normal chow. While these classic indices of DIO and NAFLD were observed such as increased circulating levels of ALT and AST, there was no difference in circulating UA levels. Obese female mice also demonstrated increased hepatic triglyceride (TG), cholesterol, and cholesteryl ester. In addition, several markers of hepatic inflammation were significantly increased. Also, alterations in the expression of redox-related enzymes were observed in obese mice compared to lean controls including increases in extracellular superoxide dismutase (Sod3), heme oxygenase (Ho)-1, and xanthine dehydrogenase (Xdh). Interestingly, hepatic UA levels were significantly elevated (~2-fold) in obese mice compared to their lean counterparts. These data demonstrate female mice assume a similar metabolic profile to that reported in several male models of obesity in the context of alterations in glucose tolerance, hepatic steatosis, and elevated transaminases (ALT and AST) in the absence of hyperuricemia affirming the need for further study.

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

The role of obesity, type 2 diabetes, and metabolic factors in gout: A Mendelian randomization study

BACKGROUND

Several epidemiological studies have reported a possible correlation between risk of gout and metabolic disorders including type 2 diabetes, insulin resistance, obesity, dyslipidemia, and hypertension. However, it is unclear if this association is causal.

METHODS

We used Mendelian randomization (MR) to evaluate the causal relation between metabolic conditions and gout or serum urate concentration by inverse-variance-weighted (conventional) and weighted median methods. Furthermore, MR-Egger regression and MR-pleiotropy residual sum and outlier (PRESSO) method were used to explore pleiotropy. Genetic instruments for metabolic disorders and outcome (gout and serum urate) were obtained from several genome-wide association studies on individuals of mainly European ancestry.

RESULTS

Conventional MR analysis showed a robust causal association of increasing obesity measured by body mass index (BMI), high-density lipoprotein cholesterol (HDL), and systolic blood pressure (SBP) with risk of gout. A causal relationship between fasting insulin, BMI, HDL, triglycerides (TG), SBP, alanine aminotransferase (ALT), and serum urate was also observed. These results were consistent in weighted median method and MR-PRESSO after removing outliers identified. Our analysis also indicated that HDL and serum urate as well as gout have a bidirectional causal effect on each other.

CONCLUSIONS

Our study suggested causal effects between glycemic traits, obesity, dyslipidemia, blood pressure, liver function, and serum urate as well as gout, which implies that metabolic factors contribute to the development of gout via serum urate, as well as potential benefit of sound management of increased serum urate in patients with obesity, dyslipidemia, hypertension, and liver dysfunction.

Simple metabolic markers associated with tophaceous gout

INTRODUCTION

The relationship between tophaceous gout and metabolic markers is not well understood. The aim of this study was to compare the correlations between different metabolic markers and tophi and evaluate their potential predictive values for tophus.

METHOD

We analysed the data of gout patients in Beijing Jishuitan Hospital from 2013 to 2020. Ten laboratory indicators (UA, eGFR, underexcretion, GLU, TRIG, HDL-C, ALT, TBIL, γ-GT and UPH) were included to evaluate the relationship between tophaceous gout and metabolic markers.

RESULTS

Tophi was present in 14.7% (119/808) of gout patients. UA, eGFR, ALT and γ-GT were independently related to the development of tophi; UA and γ-GT were positively correlated. The γ-GT/ALT ratio and UA/eGFR ratio showed a positive correlation with tophi, with (rho, P) of (0.305, < 0.001) and (0.195, < 0.001), respectively. The γ-GT/ALT ratio showed the best classificatory performance (AUC = 0.749, P < 0.001) for tophi among the four positive correlation indicators. With increasing integer γ-GT/ALT ratio, the incidence of tophi (4.9%, 9.7%, 22.3% and 38.4%, P < 0.001), chronic kidney disease (2.5%, 5.2%, 12.3% and 19.2%, P < 0.001) and hyperuricemia over 10 years (6.6%, 10.7%, 18.5% and 26.4%, P < 0.001) showed a progressive increase. The γ-GT/ALT ratio was positively correlated with the number of tophi and duration of hyperuricemia, negatively correlated with eGFR.

CONCLUSIONS

UA, eGFR, γ-GT and ALT were independently associated with tophi. The γ-GT/ALT ratio may be used as a predictor or monitor of tophi.

Gender effect of hyperuricemia on the development of nonalcoholic fatty liver disease (NAFLD): A clinical analysis and mechanistic study

BACKGROUND AND AIMS

Hyperuricemia is a risk factor for nonalcoholic fatty liver disease (NAFLD), however, the effect of gender on the hyperuricemia-related NAFLD development remains unclear. Here, we evaluated the clinical characteristics of NAFLD patients with hyperuricemia, and experimentally recapitulated this condition in male rats in order to gain insights on the possible impact of gender on the development of NAFLD in patients with hyperuricemia.

METHODS

The clinical characteristics of 238 NAFLD patients, together with the impacts of hyperuricemia on the major parameters related to the development of NALFD were analysed. In animal studies, NAFLD with hyperuricemia was induced in male SD rats using high-yeast high-fat diet containing potassium oxonate. The impact of uric acids on liver pathology, and the expression patterns of key molecules involved in the development of NAFLD, including silent information regulator 1 (SIRT1), nuclear factor kappa B subunit p65 (NF-κB p65), fork-head box class O-3a (FOXO3a), androgen receptor (AR), and xanthine oxidase (XO) were analysed.

RESULTS

Male NAFLD patients with hyperuricemia displayed more frequent and extensive liver injury than those in female patients. In male rats, hyperuricemia was associated with increased levels of insulin, alanine aminotransferase (ALT) and triglyceride (TG). At the molecular level, hyperuricemia was associated with decreased expression of SIRT1 and its phosphorylation, phosphorylation of FOXO3a, increased expression of AR and XO, and deacetylation of NF-κB P65.

CONCLUSIONS

Hyperuricemia is a compounding factor for NAFLD, particularly in males. The severer hepatic injury observed in male NAFLD patients may be attributed to the suppression of SIRT1 signalling induced by hyperuricemia.

Hepatic Safety of Febuxostat Compared with Allopurinol in Gout Patients with Fatty Liver Disease

OBJECTIVE

Febuxostat has superior renal safety to allopurinol, but data on its hepatic safety are limited. Thus we compared the hepatotoxicity of febuxostat and allopurinol, and the clinical factors associated with hepatotoxicity, in patients with gout and fatty liver disease (FLD).

METHODS

We included gout patients treated with allopurinol or febuxostat who were diagnosed with fatty liver based on ultrasonography or computed tomography. Hepatotoxicity was defined as follows: (1) elevation of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) at least 3× the upper limit of normal, when the baseline AST/ALT was normal; or (2) doubling of the baseline AST/ALT, when the baseline AST/ALT was elevated. The factors associated with hepatotoxicity were evaluated by Cox regression analysis.

RESULTS

Of 134 patients identified with gout and FLD, 32 (23.9%) received febuxostat and 102 (76.1%) received allopurinol. There were no significant differences in age, body mass index, comorbidity, or disease severity between the groups; however, the incidence of hepatotoxicity was significantly lower in the febuxostat group (3/32, 9.4%) than in the allopurinol group (36/102, 35.3%, p = 0.005). Diabetes (HR 3.549, 95% CI 1.374-9.165, p = 0.009) and colchicine use (HR 11.518, 95% CI 5.515-24.054, p < 0.001) were associated with a higher risk of hepatotoxicity, whereas febuxostat use was associated with a lower risk of hepatotoxicity (HR 0.282, 95% CI 0.086-0.926, p = 0.037).

CONCLUSION

In the 32 patients studied, febuxostat was well tolerated in patients with gout and FLD. However, the presence of diabetes and colchicine use may increase the risk of hepatotoxicity.

Increased Serum Uric Acid over five years is a Risk Factor for Developing Fatty Liver

The prevalence of fatty liver disease (FLD) is increasing. To clarify risk factors for developing FLD, we analyzed a database from healthy Japanese adults who had annual medical check-ups in 2004 and reexamined in 2009. We used the fatty liver index (FLI) to classify participants as FLD (FLI ≥60), borderline FLD (30≤ FLI <60), and normal liver (FLI <30). Subjects with hepatitis B or C virus infection and subjects with FLD at the baseline were excluded. The cumulative incidence of FLD from normal liver and from borderline FLD over five years were 0.65% (52/8,025) and 12.9% (244/1,888), respectively. After multiple adjustments, higher serum uric acid (SUA) (OR:1.92; 95% CI:1.40–2.63) and increased SUA change (OR:3.734; 95% CI:2.57–5.42) became risk factors for developing FLD from normal liver, as well as younger age and higher body mass index. The risk factors for developing FLD from borderline FLD were similar. Not only higher baseline SUA but also increased SUA change became independent risks for developing FLD.

Uric acid and obesity-related phenotypes in postmenopausal women

The aim of this study was to find the genetic, metabolic, and nutritional risk factors, which can be associated with uric acid (UA) level. The risk factors related to uricemia were assessed among 271 postmenopausal women without cardiometabolic disorders and hypolipidemic/hypoglycemic treatment selected from a cohort of 1423 obese postmenopausal women. The bioimpedance analysis and biochemical and genetic analyses were performed in two groups characterized by serum UA ≥ 4 mg/dL (238 μmol/L) and < 4 mg/dL. The TaqMan-based real-time PCR method was applied to assess the role of Pro12Ala of peroxisome proliferation-activated receptor (PPAR)gamma-2 and Trp64Arg of beta-3-adrenergic receptor (ADRB) polymorphisms. Women with UA level ≥ 4 mg/dL were characterized by larger body mass, triceps skinfold, waist circumference, body fat amount, and serum insulin, glucose, and triglyceride levels. There was no difference in dietary habits between the analyzed groups. Body mass, waist circumference, body fat amount, diastolic blood pressure, and serum insulin, glucose, high-density lipoprotein, and triglyceride levels, Homeostasis Model Assessment-Insulin Resistance, and energy from the dietary fat influence the UA level ≥ 4 mg/dL; however, the serum UA was not determined by Pro12Ala and Trp64Arg polymorphism analyses. The model of linear regression revealed that the group characterized by body mass index  ≥ 25 kg/m2 and glucose ≥ 100 mg/dL has 4 times increased risk of UA level (p = 0.0009); after adding triglycerides ≥ 150 mg/dL, the risk of UA increased 7 times (p = 0.0216). Increasing the level of UA ≥ 4 mg/dL is associated with overweight, hyperglycemia, and hypertriglyceridemia in women without a history of cardiometabolic disorders. A better management of metabolic factors could help prevent further increase in UA levels.

Fructose and sugar: A major mediator of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome; its rising prevalence parallels the rise in obesity and diabetes. Historically thought to result from overnutrition and a sedentary lifestyle, recent evidence suggests that diets high in sugar (from sucrose and/or high-fructose corn syrup [HFCS]) not only increase the risk of NAFLD, but also non-alcoholic steatohepatitis (NASH). Herein, we review the experimental and clinical evidence that fructose precipitates fat accumulation in the liver, due to both increased lipogenesis and impaired fat oxidation. Recent evidence suggests that the predisposition to fatty liver is linked to the metabolism of fructose by fructokinase C, which results in ATP consumption, nucleotide turnover and uric acid generation that mediate fat accumulation. Alterations to gut permeability, the microbiome, and associated endotoxemia contribute to the risk of NAFLD and NASH. Early clinical studies suggest that reducing sugary beverages and total fructose intake, especially from added sugars, may have a significant benefit on reducing hepatic fat accumulation. We suggest larger, more definitive trials to determine if lowering sugar/HFCS intake, and/or blocking uric acid generation, may help reduce NAFLD and its downstream complications of cirrhosis and chronic liver disease.

Colchicine-Induced Hepatotoxicity

Drug-induced injury (DILI) is a frequent cause of abnormal liver tests and a leading cause of liver failure in the United States. Colchicine has long been used as a systemic anti-inflammatory agent for treatment of gout by inhibiting mitotic activity and neutrophil function. We present the first case of colchicine-induced hepatoxicity, supported by histopathologic findings characteristic of colchicine-induced injury and resolution of liver enzyme abnormalities after its discontinuation. Colchicine-associated DILI has implications for the evaluation of patients with abnormal liver tests and gout, especially for patients with alcoholism and non-alcoholic fatty liver disease, in whom there is an increased incidence of gout.

Association between the hyperuricemia and nonalcoholic fatty liver disease risk in a Chinese population: A retrospective cohort study

Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease associated with high levels of serum uric acid (SUA). However, whether this relationship applies in obese subjects has been unclear, and no cohort study has previously been conducted in non-obese subjects. We therefore performed a retrospective cohort study among employees of seven companies in China to investigate whether hyperuricemia was independently associated with NAFLD in obese and non-obese subjects, respectively. A total of 2383 initially NAFLD-free subjects were followed up for four years, and 15.2% (363/2383) developed NAFLD. Hyperuricemia subjects had a higher cumulative incidence than did those with normouricemia (29.0% vs. 12.9%, P<0.001). Cox proportional hazard regression analyses showed that baseline hyperuricemia was significantly associated with risk of developing NAFLD in non-obese subjects. This relationship was significantly independent of baseline age, gender, metabolic syndrome components, and other clinical variables (RR = 1.389, 95%CI: 1.051-2.099). However, this association did not exist in obese subjects (RR = 1.010, 95%CI: 0.649-1.571). The independent effect of hyperuricemia on NAFLD was stronger in females (RR = 2.138, 95%CI: 1.050-4.355) than in males (RR = 1.435, 95%CI: 1.021-2.018). In conclusion, further studies are needed to explore the different mechanisms between obese and non-obese subjects, and the reason hyperuricemia raises NAFLD risk in females more than in males.

Autoimmune hepatitis following drug-induced liver injury in an elderly patient

We describe a case of autoimmune hepatitis (AIH) that may have occurred following drug-induced liver injury with camostat mesilate and/or benzbromarone in an elderly patient. The patient's liver biopsy showed chronic active hepatitis and autoimmune hepatitis. Stopping the use of these drugs did not lead to complete remission, but the use of a low dose of corticosteroids completely cured his liver dysfunction. In the present case, liver dysfunction was caused by an autoimmune mechanism. Special attention should be paid to idiopathic AIH and drug-induced AIH in elderly patients.

The Potential Biomarkers to Identify the Development of Steatosis in Hyperuricemia

Hyperuricemia (HU) often progresses to combine with non-alcoholic fatty liver disease (NAFLD) in the clinical scenario, which further exacerbates metabolic disorders; early detection of biomarkers, if obtained during the HU progression, may be beneficial for preventing its combination with NAFLD. This study aimed to decipher the biomarkers and mechanisms of the development of steatosis in HU. Four groups of subjects undergoing health screening, including healthy subjects, subjects with HU, subjects with HU combined with NAFLD (HU+NAFLD) and subjects with HU initially and then with HU+NAFLD one year later (HU→HU+NAFLD), were recruited in this study. The metabolic profiles of all subjects' serum were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry. The metabolomic data from subjects with HU and HU+NAFLD were compared, and the biomarkers for the progression from HU to HU+NAFLD were predicted. The metabolomic data from HU→HU+NAFLD subjects were collected for further verification. The results showed that the progression was associated with disturbances of phospholipase metabolism, purine nucleotide degradation and Liver X receptor/retinoic X receptor activation as characterized by up-regulated phosphatidic acid, cholesterol ester (18:0) and down-regulated inosine. These metabolic alterations may be at least partially responsible for the development of steatosis in HU. This study provides a new paradigm for better understanding and further prevention of disease progression.

Hyperuricemia and risk of nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Previous studies have suggested a possible association between hyperuricemia and nonalcoholic fatty liver disease (NAFLD), but the risk of NAFLD in individuals with hyperuricemia had not been fully quantified. A systematic review and meta-analysis of relevant studies was carried out to estimate the influence of hyperuricemia on the risk of NAFLD.

METHODS

PubMed, Embase, Web of Science, and Wanfang databases were searched for cohort or cross-sectional studies assessing the association between hyperuricemia and NAFLD. Relative risks (RRs) with 95% confidence intervals (95% CIs) were pooled using a random-effects model to estimate the impact of hyperuricemia on the risk of NAFLD.

RESULTS

Thirteen studies from 12 articles were finally included in the meta-analysis. There were a total of 117,712 participants and 28,446 (24.2%) NAFLD cases. Individuals with hyperuricemia had an obviously increased risk of NAFLD compared with those without hyperuricemia (RR=1.79, 95% CI 1.55-2.07, P<0.001). Increased risk of NAFLD was obviously associated with hyperuricemia in both men (RR=1.26, 95% CI 1.15-1.37, P<0.001) and women (RR=2.01, 95% CI 1.58-2.56, P<0.001). Subgroup analyses further identified the robustness of the association between hyperuricemia and NAFLD.

CONCLUSION

Hyperuricemia is associated with an increased risk of NAFLD in Asian populations. Further prospective cohort studies are needed to assess the impact of hyperuricemia on the risk of NAFLD in Western countries.

Impact of gout on the risk of atrial fibrillation

OBJECTIVES

To examine the risk of atrial fibrillation (AF) at the time of first diagnosis of gout compared with matched controls and to follow incident gout patients and their matched controls after diagnosis to compare their subsequent risk of AF.

METHODS

From the UK Clinical Practice Research Data-link, 45 378 incident gout patients and 45 378 age-, sex-, practice-, registration year- and index year-matched controls were identified. Index dates were initial diagnosis date for gout patients and their matched controls. The risk of AF at diagnosis [odds ratios (ORs), using conditional logistic regression] and after the diagnosis of gout [hazard ratios (HRs), using Cox proportional models] were estimated, adjusted for BMI, smoking, alcohol consumption, ischaemic heart disease, heart failure, heart valve disease, hyperthyroidism and other comorbidities and medications.

RESULTS

The prevalence of AF at index date in gout patients (male, 72.3%; mean age, 62.4 ± 15.1 years) was 7.42% (95% CI 7.18, 7.66%) and in matched controls 2.83% (95% CI 2.67, 2.98%). The adjusted OR (95% CI) was 1.45 (1.29, 1.62). The cumulative probability of AF at 1, 2, 5 and 10 years after index date was 1.08, 2.03, 4.77 and 9.68% in gout patients and 0.43, 1.08, 2.95 and 6.33% in controls, respectively (log-rank test, P < 0.001). The adjusted HR (95% CIs) was 1.09 (1.03, 1.16).

CONCLUSION

This population-based study indicates that gout is independently associated with a higher risk of AF at diagnosis and the risk is also higher after the diagnosis.

Epidemiological modifiers of non-alcoholic fatty liver disease: Focus on high-risk groups

An improved understanding of non-alcoholic fatty liver disease epidemiology would lead to identification of individuals at high risk of developing chronic liver disease and extra-hepatic complications, thus contributing to more effective case finding of non-alcoholic fatty liver disease among selected groups. We aimed to illustrate the epidemiology of non-alcoholic fatty liver disease in high-risk groups, which were identified based on existing literature. To this end, PubMed was searched to retrieve original articles published until May 2015 using relevant and pertinent keywords "nonalcoholic fatty liver disease" and "diabetes", "obesity", "hyperlipidaemia", "familial heterozygous hypobetalipoproteinaemia", "hypertension", "metabolic syndrome", "ethnicity", "family history" or "genetic polymorphisms". We found that age, sex and ethnicity are major physiological modifiers of the risk of non-alcoholic fatty liver disease, along with belonging to "non-alcoholic fatty liver disease families" and carrying risk alleles for selected genetic polymorphisms. Metabolic syndrome, diabetes, obesity, mixed hyperlipidaemia and hypocholesterolaemia due to familial hypobetalipoproteinaemia are the major metabolic modifiers of non-alcoholic fatty liver disease risk. Compared with these metabolic conditions, however, arterial hypertension appears to carry a relatively more modest risk of non-alcoholic fatty liver disease. A better understanding of the epidemiology of non-alcoholic fatty liver disease may result in a more liberal policy of case finding among high-risk groups.

Epidemiology and management of gout in Taiwan: a nationwide population study

INTRODUCTION

Gout is the most common inflammatory arthritis worldwide and is the only type of chronic arthritis that potentially can be 'cured'. However, data on gout incidence, prevalence and management, assessed at multiple time points in the same population, are sparse, particularly in Asian populations. The aim of this study was to describe trends in the epidemiology of gout in the general population of Taiwan.

METHODS

The National Health Insurance Research Database was used to identify patients with gout and to estimate the prevalence and incidence of gout for each calendar year from 2005 to 2010. The pattern of gout management was also examined.

RESULTS

Of 23,371,362 beneficiaries in 2010, there were 1,458,569 prevalent and 56,595 incident cases of gout, giving a prevalence of 6.24% (95% confidence interval (CI), 6.23% to 6.25%) and an incidence of 2.74 (95% CI, 2.72 to 2.76) per 1,000 person-years. The annual percentage change (APC) of the standardised prevalence was -0.7% (95% CI, -1.7% to 0.3%; P=0.14), suggesting that the prevalence of gout was essentially the same throughout the study period. However, The APC of incidence was -13.4 (95% CI, -16.1 to -10.6) between 2005 and 2007 and -2.1 (95% CI, -10.4 to 7.1) between 2007 and 2010. Regions with the highest prevalence and incidence were eastern coastal counties and offshore islets, where indigenous people are clustered. Among prevalent gout cases in 2010, only 22.93% (95% CI, 22.87% to 23.00%) were prescribed urate-lowering treatment (ULT), which remained unchanged between 2005 and 2010 at an APC of 0.0 (95% CI, -3.8 to 4.0). Uricosuric agents were more commonly prescribed than xanthine oxidase inhibitors in Taiwan.

CONCLUSIONS

In Taiwan, 1 in 16 people have gout. Whereas the incidence has decreased recently, the prevalence remains unchanged. Management of gout in Taiwan is poor, with only one in five affected people being treated with ULT.

Comorbidities in patients with gout prior to and following diagnosis: case-control study

Objectives

To determine the burden of comorbidities in patients with gout at diagnosis and the risk of developing new comorbidities post diagnosis.

Methods

There were 39 111 patients with incident gout and 39 111 matched controls identified from the UK Clinical Practice Research Data-link. The risk of comorbidity before (ORs) and after the diagnosis of gout (HRs) were estimated, adjusted for age, sex, diagnosis year, body mass index, smoking and alcohol consumption.

Results

Gout was associated with adjusted ORs (95% CIs) of 1.39 (1.34 to 1.45), 1.89 (1.76 to 2.03) and 2.51 (2.19 to 2.86) for the Charlson index of 1–2, 3–4 and ≥5, respectively. Cardiovascular and genitourinary diseases, in addition to hyperlipidaemia, hypothyroidism, anaemia, psoriasis, chronic pulmonary diseases, osteoarthritis and depression, were associated with a higher risk for gout. Gout was also associated with an adjusted HR (95% CI) of 1.41 (1.34 to 1.48) for having a Charlson index ≥1. Median time to first comorbidity was 43 months in cases and 111 months in controls. Risks for incident comorbidity were higher in cardiovascular, genitourinary, metabolic/endocrine and musculoskeletal diseases, in addition to liver diseases, hemiplegia, depression, anaemia and psoriasis in patients with gout. After additionally adjusting for all comorbidities at diagnosis, gout was associated with a HR (95% CI) for all-cause mortality of 1.13 (1.08 to 1.18; p<0.001).

Conclusions

The majority of patients with gout have worse pre-existing health status at diagnosis and the risk of incident comorbidity continues to rise following diagnosis. The range of associated comorbidities is broader than previously recognised and merits further evaluation.

Development, external validation, and comparative assessment of a new diagnostic score for hepatic steatosis

OBJECTIVES

We used data from population-based studies to determine the accuracy of the Fatty Liver Index (FLI) and the Hepatic Steatosis Index (HSI) in determining individual risk of hepatic steatosis. We also developed a new risk scoring system and validated all three indices using external data.

METHODS

We used data from the Study of Health in Pomerania (SHIP; n=4,222), conducted in North-eastern Germany, to validate the existing scoring systems and to develop our own index. Data from the South German Echinococcus Multilocularis and Internal Diseases in Leutkirch (EMIL) study (n=2,177) were used as an external validation data set. Diagnostic performance was evaluated in terms of discrimination (area under the receiver operating characteristic curve (AUC)) and calibration plots. We applied boosting for generalized linear models to select relevant diagnostic separators.

RESULTS

The FLI accurately discriminated patients with fatty liver disease from those without (AUC=0.817) but had poor calibration, in that predicted risks differed considerably from observed risks, based on SHIP data. The FLI performed well in discrimination and calibration in the analysis of EMIL data (AUC=0.890). The HSI performed worse than the FLI in analysis of both data sets (SHIP: AUC=0.782 and EMIL: AUC=0.841), showing an extremely skewed calibration. Our newly developed risk score had a good performance in the development data set (SHIP: AUC=0.860) and also good discrimination ability in the validation data (EMIL: AUC=0.876), but it had low calibration based on the validation data set.

CONCLUSIONS

We compared the ability of the FLI, HSI, and our own scoring system to determine the risk of hepatic steatosis using two population-based data sets (one for the development of our own system and one for validation). In the development and independent replication data set, all three indices discriminated well between patients with and without hepatic steatosis, but the predicted risks did not match well with the observed risks, when applied to external data. Scoring systems for fatty liver disease could depend on methodological standardization of ultrasound diagnosis and laboratory measurements.

Clinical characteristics of and relationship between metabolic components and renal function among patients with early-onset juvenile tophaceous gout

OBJECTIVE

Age of onset of gout has recently decreased; however, patients with early-onset gout remain uncommon, and relevant information is scant. We hypothesized that these patients might exhibit differences in serum urates and other comorbidities compared with adult-onset patients.

METHODS

Early-onset gout patients (i.e., juveniles) with (n = 40) and without tophi (n = 47) were enrolled for study. Their clinical characteristics were compared with those of 353 patients with middle-age-onset tophaceous gout and 64 age-matched healthy participants.

RESULTS

Early-onset gout patients with tophi exhibited significantly higher body mass indices and serum urate levels and lower estimated glomerular filtration rates (eGFR) than did those without tophi. Early-onset gout patients with or without tophi demonstrated significantly abnormal lipid profiles and impaired liver or renal function compared with healthy patients. Serum urate levels and gout duration were identified as the principal determinants of tophi development. The presence of tophi might be crucial in decreasing eGFR, which is inversely related to tophi duration or gout duration. Unexpectedly, the most common site of initial gout attacks in early-onset tophaceous gout patients was the ankle, not the toe, which was the most common site in middle-age-onset tophaceous gout patients. The most common site of first tophi occurrence in early-onset patients was a finger, not a toe, which was the most common site in middle-age-onset patients.

CONCLUSION

Early-onset tophaceous gout patients are more likely to exhibit comorbidities and renal dysfunction than middle-age-onset patients and exhibit distinct first sites of gout attack and tophi occurrence patterns.

The prevalence of gout in an urban area of Izmir, Turkey: a population-based epidemiological study

OBJECTIVES

This study aimed to determine the prevalence of gout in a general Turkish population, according to the American College of Rheumatology (Wallace) criteria proposed for gout classification.

METHODS

This study was conducted in two districts of Izmir Province in Turkey, and involved 2835 subjects of ≥ 20 years of age. In the first stage, face-to-face interviews were performed at the subjects' registered households. In the second stage, subjects who gave positive answers in the screening questionnaire were invited to the hospital for a full examination, which included a detailed medical history, medication use and blood tests.

RESULTS

A total of 2887 subjects were contacted, and complete interviews were obtained for 2835 (1551 women, 1284 men). A total of 312 subjects (227 women, 85 men) reported experiencing a short period of joint pain accompanied by swelling, redness or reduced range of movement, and 247 (79%) of these patients underwent a detailed clinical examination in the hospital. Gout was diagnosed in 11 patients (8 men, 3 women). We found minimum age- and sex-adjusted prevalence rates of gout of 0.31% (95% CI: 0.16-0.61) in subjects of ≥ 20 years of age, and 0.72% (95% CI: 0.37-1.24) in subjects of ≥ 40 years of age.

CONCLUSIONS

Our data suggest that the estimated prevalence of gout (0.31%) is lower than the previously published estimated prevalence of rheumatoid arthritis (0.36%) in the same study population (14 definite rheumatoid arthritis cases among the 2835 subjects).

The prevalence of nonalcoholic fatty liver disease and relationship with serum uric acid level in Uyghur population

OBJECTIVE

To investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and the association of serum uric acid level with NAFLD in Uygur people, Xinjiang.

METHODS

A total of 2241 Uyghur persons (1214 males and 1027 females) were interviewed for physical checkups from 2011 to 2012. The clinical data of questionnaire survey, body mass index (BMI), abdominal circumference, blood pressure, blood sugar, blood lipid, and serum uric acid level were collected for analysis.

RESULTS

The prevalence rates of NAFLD determined by abdominal ultrasound examination and hyperuricemia were 43.9% and 8.4%, respectively. The persons with NAFLD had significantly higher serum uric acid levels than those without NAFLD (320 ± 88 versus 254 ± 80 μ mol/L; P < 0.001). The prevalence rate of NAFLD was significantly higher in subjects with hyperuricemia than that in those without hyperuricemia (78.19% versus 40.83%; P < 0.001), and the prevalence rate increased with progressively higher serum uric acid levels (P < 0.001). Multiple regression analysis showed that hyperuricemia was associated with an increased risk of NAFLD (odds ratio (OR): 2.628, 95% confidence interval (CI): 1.608-4.294, and P < 0.001).

CONCLUSION

Serum uric acid level was significantly associated with NAFLD, and the prevalence rate of NAFLD increased with progressively higher serum uric acid levels.

Non-alcoholic fatty liver disease: factors associated with its presence and onset

Non-alcoholic fatty liver disease (NAFLD) may progress to cirrhosis, liver failure, and complicated hepatocellular carcinoma. In addition, NAFLD is a risk factor for the development of other serious diseases, such as diabetes or cardiovascular disease. Therefore, the detection of early-stage NAFLD is important. Many studies have described the factors that predict the presence of NAFLD and its onset, and several markers have been identified. These markers have enabled the identification of high-risk patients and have improved routine medical practice. To prevent advanced disease, clinicians need to have simple markers that predict the onset of NAFLD so that interventions can be started at much earlier stages of disease. This review summarizes the current state of knowledge regarding independent factors, as reported in large studies, that predict the presence of NAFLD and its onset, especially markers that can be used in daily medical practice, such as physical measurements and blood tests.

Serum uric acid levels and non-alcoholic fatty liver disease in Uyghur and Han ethnic groups in northwestern China

OBJECTIVE: The aim of this study was to compare serum uric acid values in two ethnically distinct Chinese populations: Uyghur, with a high prevalence of nonalcoholic fatty liver disease, and Han, with a lower prevalence. SUBJECTS AND METHODS: Serum uric acid and several clinical features and laboratory tests relevant to the metabolic syndrome were measured in 4,157 Uyghur and 6,448 Han subjects in a health examination program. The diagnosis of hepatic steatosis was established by abdominal ultrasound examination. RESULTS: The prevalence of nonalcoholic fatty liver disease was 42.3% and 33.3% among Uyghur and Han subjects, respectively. The corresponding prevalence of hyperuricemia was 8.8% and 14.7%. The mean concentration of serum uric acid in Uyghurs also was lower than in Hans (282.75 vs. 310.79 µmol/L; p < 0.01). However, in both populations, the prevalence of nonalcoholic fatty liver disease was increased in association with increasing serum uric acid concentrations, a trend that was more pronounced in Uyghur than in Han subjects (OR 3.279 and 3.230, respectively). Several components of the metabolic syndrome were more pronounced in Uyghurs than in Hans. CONCLUSIONS: Serum uric acid is an independent risk factor in nonalcoholic fatty liver disease in both Uyghurs and Hans, but other risk factors may be more important in the differences in prevalence of the disease between the two ethnic groups.

Elevated serum uric acid levels are associated with non-alcoholic fatty liver disease independently of metabolic syndrome features in the United States: Liver ultrasound data from the National Health and Nutrition Examination Survey

OBJECTIVE

Experimental and observational studies suggest a role for uric acid in non-alcoholic fatty liver disease (NAFLD). We examined the association between serum uric acid levels and NAFLD in a large population-based study from the United States.

MATERIALS/METHODS

A cross-sectional analysis of 10,732 nondiabetic adults who participated in the National Health and Nutrition Examination Survey 1988-1994. Sex specific uric acid quartiles were defined: ≤5.2, 5.3-6.0, 6.1-6.9, and >6.9mg/dL for men and ≤3.7, 3.8-4.5, 4.6-5.3, and >5.3mg/dL for women. NAFLD presence and severity were defined by ultrasonographic detection of steatosis in the absence of other liver diseases. We modeled the probability that more severe NAFLD would be associated with the highest quartiles of uric acid.

RESULTS

Compared to the 1st quartile, the odds ratio for NAFLD was 1.79 (95% C.I. 1.49-2.15, p<0.001) and 3.14 (95% C.I. 2.63-3.75, p<0.001) for the 3rd and 4th quartiles, respectively. After adjusting for demographics, hypertension, waist circumference, triglycerides, high-density lipoprotein-cholesterol, homeostasis model assessment-estimated insulin resistance, estimated glomerular filtration rate, and aspartate aminotransferase, uric acid (4th quartile) was significantly associated with NAFLD (odds ratio 1.43; 95% C.I. 1.16-1.76, p<0.001). Positive parameter estimates suggest increasing uric acid is associated with greater severity of NAFLD.

CONCLUSIONS

Elevated uric acid level is independently associated with ultrasound-diagnosed NAFLD in a nationally representative sample of United States nondiabetic adults. Increasing uric acid is associated with increasing severity of NAFLD on ultrasonography. These findings warrant further studies on the role of uric acid in NAFLD.

Association between serum uric acid and nonalcoholic fatty liver disease in the US population

BACKGROUND/PURPOSE

Studies conducted in Eastern Asia suggest that serum uric acid (SUA) level is highly related to nonalcoholic fatty liver disease (NAFLD). However, limited information is available in the USA. Our objective was to determine the association between NAFLD and SUA levels in the USA and to determine if this is independent of age, sex, and components of metabolic syndrome (MetS).

METHODS

We analyzed 5370 men and women aged 20-74 years from the Third National Health and Nutrition Examination Survey (NHANES III) (1988-1994) in the USA. We calculated the prevalence and odds ratio (OR) of NAFLD and elevated liver enzymes by SUA and sex-specific quintiles of SUA, adjusting for multiple factors.

RESULTS

The prevalence of NAFLD was higher in participants with higher SUA levels (10.9%, 9.6%, 15.9%, 21.8% and 33.1%, respectively, from the second to the fifth sex-specific quintile of uric acid). After adjustment, individuals with hyperuricemia were more likely to have NAFLD (OR: 1.4, 95% CI: 1.1-1.9). Similarly, the adjusted odds of NAFLD were increasingly higher from the second to the fifth quintile of SUA (ORs: 0.8, 1.2, 1.5 and 1.7, respectively; p < 0.01) as compared to the lowest quintile. Finally, individuals with hyperuricemia were more likely to have elevated liver enzymes (aspartate aminotransferase or alanine aminotransferase) (adjusted OR: 1.8, 95% CI: 1.1-2.7).

CONCLUSION

NAFLD and SUA levels were strongly and independently associated in this nationally representative sample of men and women after adjustment for multiple factors.

Uric acid stimulates fructokinase and accelerates fructose metabolism in the development of fatty liver

Excessive dietary fructose intake may have an important role in the current epidemics of fatty liver, obesity and diabetes as its intake parallels the development of these syndromes and because it can induce features of metabolic syndrome. The effects of fructose to induce fatty liver, hypertriglyceridemia and insulin resistance, however, vary dramatically among individuals. The first step in fructose metabolism is mediated by fructokinase (KHK), which phosphorylates fructose to fructose-1-phosphate; intracellular uric acid is also generated as a consequence of the transient ATP depletion that occurs during this reaction. Here we show in human hepatocytes that uric acid up-regulates KHK expression thus leading to the amplification of the lipogenic effects of fructose. Inhibition of uric acid production markedly blocked fructose-induced triglyceride accumulation in hepatocytes in vitro and in vivo. The mechanism whereby uric acid stimulates KHK expression involves the activation of the transcription factor ChREBP, which, in turn, results in the transcriptional activation of KHK by binding to a specific sequence within its promoter. Since subjects sensitive to fructose often develop phenotypes associated with hyperuricemia, uric acid may be an underlying factor in sensitizing hepatocytes to fructose metabolism during the development of fatty liver.

Uric acid induces hepatic steatosis by generation of mitochondrial oxidative stress: potential role in fructose-dependent and -independent fatty liver

BACKGROUND

Uric acid is an independent risk factor in fructose-induced fatty liver, but whether it is a marker or a cause remains unknown.

RESULTS

Hepatocytes exposed to uric acid developed mitochondrial dysfunction and increased de novo lipogenesis, and its blockade prevented fructose-induced lipogenesis.

CONCLUSION

Rather than a consequence, uric acid induces fatty liver

SIGNIFICANCE

Hyperuricemic people are more prone to develop fructose-induced fatty liver. Metabolic syndrome represents a collection of abnormalities that includes fatty liver, and it currently affects one-third of the United States population and has become a major health concern worldwide. Fructose intake, primarily from added sugars in soft drinks, can induce fatty liver in animals and is epidemiologically associated with nonalcoholic fatty liver disease in humans. Fructose is considered lipogenic due to its ability to generate triglycerides as a direct consequence of the metabolism of the fructose molecule. Here, we show that fructose also stimulates triglyceride synthesis via a purine-degrading pathway that is triggered from the rapid phosphorylation of fructose by fructokinase. Generated AMP enters into the purine degradation pathway through the activation of AMP deaminase resulting in uric acid production and the generation of mitochondrial oxidants. Mitochondrial oxidative stress results in the inhibition of aconitase in the Krebs cycle, resulting in the accumulation of citrate and the stimulation of ATP citrate lyase and fatty-acid synthase leading to de novo lipogeneis. These studies provide new insights into the pathogenesis of hepatic fat accumulation under normal and diseased states.

Adherence to the Mediterranean diet and serum uric acid: the ATTICA study

OBJECTIVE

The present study aimed to explore potential associations between adherence to a Mediterranean diet and serum uric acid (UA) levels.

METHODS

The sample consisted of 2380 men and women free of cardiovascular or renal disease who participated in the ATTICA study. Dietary intake was assessed using a food frequency questionnaire (FFQ) and adherence to the Mediterranean diet was evaluated with the MedDietScore. Serum UA was measured and hyperuricaemia was defined as UA concentration > 7.0 mg/dL in men or > 6.0 mg/dL in women.

RESULTS

MedDietScore was inversely associated with UA levels (b-coefficient per quartile of the score = -0.07 ± 0.03, p = 0.02) independently of sex, presence of overweight, hypertension, or abnormal glucose metabolism, and alcohol or coffee intake. Those at the fourth quartile of MedDietScore had a 70% lower likelihood of having hyperuricaemia [odds ratio (OR) 0.30, 95% confidence interval (CI) 0.11-0.82] compared to those at the first quartile, after adjustment for several confounders. According to stratified analyses by sex, body mass index (BMI) status, hypertension, abnormal glucose, alcohol and coffee intake, the inverse association between serum UA and MedDietScore remained significant in women (b-coefficient = -0.194 ± 0.055, p < 0.001), overweight subjects (b-coefficient = -0.103 ± 0.047, p = 0.02), in those with normal glucose metabolism (b-coefficient = -0.074 ± 0.037, p = 0.04), and in those abstaining from alcohol (b-coefficient = -0.212 ± 0.073, p = 0.004) and coffee (b-coefficient = -0.221 ± 0.096, p = 0.02).

CONCLUSION

Adherence to the Mediterranean diet is associated with lower serum UA levels and lower likelihood of hyperuricaemia. These findings support a potential role of this dietary pattern in the prevention and treatment of hyperuricaemia and gout.

Risk of myocardial infarction among patients with gout: a nationwide population-based study

OBJECTIVE

To investigate the association between gout and myocardial infarction (MI) in a representative cohort in Taiwan.

METHODS

Data were collected from the Taiwan National Health Insurance database. Adults >20 years of age without history of MI were included. Patients were considered to have gout if they received a diagnosis of gout requiring medical treatment. Multivariate Cox proportional hazards models were used to evaluate the risk of MI in gout patients.

RESULTS

Of the 704 503 patients included, 26 556 (3.8%) had gout. In total, 3718 (with gout, n = 463; without gout, n = 3255) patients had an MI, 299 (with gout, n = 35; without gout, n = 264) of whom died. The incidence of MI was 2.20 and 0.60 per 1000 patient-years in individuals with and without gout, respectively (log-rank test, P < 0.001). After adjustment for age, sex and history of diabetes mellitus, hypertension, coronary heart disease (CHD), stroke and end-stage renal disease, gout was associated with MIs [hazard ratio (HR), 1.23] and non-fatal MIs (HR, 1.26). In individuals without cardiovascular risk factors, gout was associated with MIs (HR 1.84; 95% CI 1.51, 2.24) and non-fatal MIs (HR 1.80; 95% CI 1.49, 3.95), after adjustment for age and sex. Moreover, in our study population, the HRs for MI decreased as age increased.

CONCLUSION

Gout is an independent risk factor for MI, and the increased risk of MI is present even in young people and those without cardiovascular risk factors.

Epidemiology of a fast emerging disease in the Asia-Pacific region: non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is rapidly increasing in the Asia-Pacific and affects up to 30 % of the general population. In younger children, prevalence has been reported to be between 2.1 and 4.5 %. The prevalence of NAFLD increases with increasing age. NAFLD is more prevalent in men than women, but this trend fades in older age group. NAFLD is one of the most common causes of raised serum ALT levels and the latter is closely related to the presence of features of metabolic syndrome. NAFLD may contribute to metabolic syndrome in a similar way as visceral adiposity and can be an early predictor of metabolic disorders. NAFLD increases the risk of developing diabetes mellitus and is closely related to degree of glucose intolerance. A significant proportion of patients with NAFLD have impaired glucose tolerance or diabetes mellitus but with normal fasting blood glucose, highlighting the importance of oral glucose tolerance test in NAFLD patients with normal fasting blood glucose. Besides liver-related complications, NAFLD has been associated with cardiovascular complications, hyperuricemia, gout, chronic kidney disease, gallstone disease, colorectal adenomatous polyp, and polycystic ovarian syndrome. NAFLD seems to be related to host metabolic factors rather than viral factors and does not seem to affect severity of the liver disease in patients with chronic hepatitis B. On the other hand, hepatic steatosis may be related to both host metabolic and viral factors in patients with chronic hepatitis C and seems to adversely impact on the severity of liver disease and possibly response to antiviral therapy.

Severity of fatty liver on ultrasound correlates with metabolic and cardiovascular risk

Non-alcoholic fatty liver disease is associated with an increased risk of metabolic and cardiovascular diseases. Whether the severity of fatty liver on ultrasound correlates with metabolic or cardiovascular risk remains unclear. A total of 1000 people receiving health examinations were enrolled, and 126 were excluded due to the presence of HBsAg, anti-HCV, known hepatic disorders or alcohol use (>140 g/wk). Significant fatty liver consisted of moderate and severe fatty liver on ultrasound. The definition of central obesity was modified to a waist circumference of >90 cm in men and >80 cm in women. Framingham risk score was used to estimate the risk of cardiovascular disease. A total of 874 subjects (485 women and 388 men with a mean age of 52.07 ± 11.68 years) were included in the final analysis. By using logistic regression analyses stratified by gender, the odds ratio for the prevalence of diabetes mellitus, metabolic syndrome and risk of cardiovascular disease increased with increasing fatty liver status in both genders (p ≤ 0.001). The difference was not only present between individuals with fatty liver vs. non-fatty liver but also between the mild fatty liver and significant fatty liver groups (p < 0.05). In conclusion, the severity of fatty liver on ultrasound could be useful for the risk stratification of metabolic syndrome, diabetes mellitus and cardiovascular disease in clinical practice.

Elevated risk of mortality among gout patients: a comparison with the national population in Taiwan

OBJECTIVES

Accumulating evidence suggests that gout is associated with increased overall and cardiovascular mortality. Using data from a large consecutive cohort of gout sufferers who were followed for 8 years, we investigated mortality among gout sufferers and compared the results with data from the general population of Taiwan.

METHODS

The study comprised 6631 people who had gout diagnosis at outpatient department of the Chang Gung Memorial Hospital in 2000. Survival status and cause of death were ascertained by examining the National Death Registry of Taiwan through 2008.

RESULTS

During 53,048 person-years of follow-up in 6631 gout patients, 1273 (male, 941; female, 332) deaths were identified, corresponding to the crude mortality rate was 21.3 (male, 20.0; female, 26.1) per 1000 patient-years, which was significantly higher than that of the national population. As compared with the national population of Taiwan in 2000, the all-cause standardized mortality ratio (95% confidence interval) was 1.29 (1.21-1.37) for men and 1.70 (1.53-1.89) for women. Both men and women in this cohort had higher standardized mortality ratios for death due to kidney diseases (men, 3.10; women, 3.54), endocrine and metabolic diseases (men, 2.24; women, 2.71), and cardiovascular diseases (men, 1.58; women, 1.81). Multivariate Cox regression showed no difference in mortality between genders.

DISCUSSION/CONCLUSIONS

Individuals with gout have increased mortality risk in both sexes; however, the extent of risk increment is higher in women. Kidney diseases, endocrine and metabolic diseases, and cardiovascular diseases are primary causes of death.