Elevated serum uric acid levels in metabolic syndrome: an active component or an innocent bystander?

Combined effect of serum gamma-glutamyltransferase and uric acid on incidence of diabetes mellitus: A longitudinal study

Gamma-glutamyltransferase (GGT) and uric acid (UA) are novel diabetes risk factors. However, little is known about the combined effects of GGT and UA on the development of diabetes. Here, we assessed the combined effects of GGT and UA on the development of diabetes in a Korean population.We evaluated 1983 women and 2687 men without diabetes. From the baseline health screening to the follow-up examination, the development of diabetes, based on changes in GGT and UA quartile levels, was analyzed. Furthermore, the quartile of GGT and quartile of UA were analyzed together to determine any synergistic effect from the 4th quartile of GGT and UA on the development of diabetes.In women, the development of diabetes gradually increased with an increase in the circulating levels of GGT and UA. For the highest quartile of GGT and UA, hazard ratios of diabetes compared with the lowest quartile were 3.88 (95% confidence interval [CI]: 1.12-13.43, P = .032) and 7.58 (95% CI: 2.17-26.42, P = .002) after adjusting for confounders, respectively. Hazard ratios of diabetes after combining both 4th quartiles of GGT and UA were 5.29 (95% CI: 1.87-15.18, P = .002), as compared with the first and second quartiles. In men, however, the development of diabetes was not significantly different among the quartiles of UA.GGT and UA levels can synergize in predicting the development of diabetes in Korean women.

Asymptomatic hyperuricemia is independently associated with coronary artery calcification in the absence of overt coronary artery disease: A single-center cross-sectional study

Recently, the pathogenic role of uric acid (UA) in both systemic metabolic and atherosclerotic diseases has been investigated. We sought to determine the independent correlation between serum UA levels and coronary artery calcification, as a marker of subclinical atherosclerosis. A total of 4188 individuals without prior coronary artery disease or urate-deposition disease were included. All of the participants underwent multidetector computed tomography (MDCT) for the evaluation of coronary artery calcification (CAC) during their health check-ups. The subjects were divided into thre groups according to CAC scores (group 1: 0; group 2: 1-299; group 3: ≥300). After controlling for other confounders, serum UA levels were found to be positively associated with increasing CAC scores (P = 0.001). Adjusted mean serum UA levels in each CAC group were estimated to be 5.2 ± 0.1 mg/dL, 5.3 ± 0.1 mg/dL, and 5.6 ± 0.2 mg/dL from groups 1, 2, and 3, respectively. Subsequent subgroup analyses revealed that this positive association was only significant in participants who were male, relatively older, less overweight, and did not have diabetes mellitus (DM), hypertension, smoking history, or renal dysfunction. In conclusion, serum uric acid levels were independently associated with CAC score severity and this finding is particularly relevant to the subjects who were male, relatively older, less overweight (body mass index < 25 kg/m), and without a history of DM, hypertension, smoking, or renal dysfunction.

Serum Uric Acid and Impaired Glucose Tolerance: The Cardiometabolic Risk in Chinese (CRC) Study

Serum uric acid (SUA) elevation has been previously related to impaired fasting glucose and type 2 diabetes. The present study was comprehensive to examine the associations between SUA and impaired glucose tolerance (IGT) in Chinese adults. For this purpose, data were collected from a community-based health examination survey conducted in Central China; 2-h glucose (OGTT) and SUA were measured in 1956 men and women. In multivariate models, SUA levels were significantly associated with an increasing trend of 2-h glucose (OGTT) (P for trend < 0.0001). The odds ratios (OR; 95 % CI) of IGT across increasing quartiles of SUA were 1.0, 1.354 (0.948-2.087), 1.337 (0.959-2.251), and 2.192 (1.407-3.416), after adjusting for age, sex, body mass index, waist circumference, fasting insulin, blood pressure, serum lipids, serum creatinine, and estimated glomerular filtration rate. (P for trend = 0.001). In addition, we found an additive pattern between SUA and triglyceride (TG; P = 0.038) or between SUA and low-density lipoprotein cholesterol (LDL-C; P = 0.041) in relation to IGT. SUA was related to IGT in the Chinese adults, independent of other conventional metabolic risk factors. TG and LDL-C might modify the associations.

The Role of Uric Acid for Predicting Future Metabolic Syndrome and Type 2 Diabetes in Older People

OBJECTIVE

Although it is known that high uric acid (UA) level is associated with type 2 diabetes (T2DM) and metabolic syndrome (MetS), most of the previous studies were focused on adults. Since aging becomes a major problem for many societies, in this longitudinal study, we investigated the role of UA in future T2DM and MetS in a large cohort of people who were older than 65 years.

DESIGN

A cross-sectional and longitudinal study.

SETTING/PARTICIPANTS

18,907 elderly (9,732 men, 9,175 women) aged above 65 years, enrolled from health check-up centers, were classified into three subgroups by 10-year intervals (young old 65-74 years, YO; old old 75-84 years, OO; and oldest old 85-94 years, ODO), with the average follow-up period of 4.3 years.

MEASUREMENTS

The optimal cut-off values (CoVs) of baseline UA to predict future MetS and T2DM were determined by receiving operating characteristic (ROC) curve analysis. Using these CoVs of UA, the participants were divided into normal- and high-level groups of UA. Cox proportional hazard analysis was used to calculate hazard ratios (HRs) for the subjects with a high level of UA for the risk of future MetS and T2DM. In addition, Kaplan-Meier plots and log rank test were used to evaluate the time effect on the incidence of developing MetS and T2DM between the two groups.

RESULTS

In ROC curve analysis, the optimal CoVs of baseline UA were 6.0, 6.3 and 6.7 mg/dl in YO, OO, and ODO men, respectively; 5.5 and 4.9 mg/dl in YO and OO women, respectively (all p < 0.05). However, the CoVs of UA in ODO women (6.1 mg/dl) failed to show its discriminant power (p = 0.13). The Cox regression analysis showed the YO subjects with a higher baseline level of UA had a higher risk of developing MetS (HRs 1.56 and 1.58 for men and women, respectively, both p < 0.001); as for T2DM the HRs were 1.39 and 1.57. In OO men, the HRs was 1.89 for developing future MetS. However, no significant findings could be noted in the ODO group. Kaplan-Meier plots and log rank test also showed the same findings.

CONCLUSION

Our study showed that old subjects with high levels of UA will have a higher chance to have MetS and T2DM, particularly in the YO group (6.0 mg/dl for men and 5.5 mg/dl for women, respectively). Using UA as one of the metabolic biomarkers may help clinicians to early detect and prevent MetS and diabetes.

Association of metabolic syndrome and its components with hyperuricemia in a Mediterranean population

Several studies have found an association between hyperuricemia and metabolic syndrome (MS), although there are discrepancies as to which MS components play a pivotal role in this association. We aimed to investigate the association between serum uric acid (SUA) levels and MS in a Mediterranean population (eastern Spain). We performed a case-control study of 71 patients with MS and 122 healthy controls. MS was defined according to the revised National Cholesterol Education Program Adult Treatment Panel III modified criteria. Hyperuricemia was defined as SUA levels >6.55 mg/dL. We determined biochemical, lipidic and inflammatory parameters along with uric acid. Patients with MS showed a higher risk of hyperuricemia than those without MS (OR: 2.87 95% CI: 1.48- 5.55; p = 0.002). In turn, the unadjusted logistic regression analysis showed that hyperuricemia is associated with a higher risk of presenting all the MS components, except hypertension; i.e., hypertriglyceridemia, low HDL-cholesterol, abdominal obesity and glucose intolerance were predictors for hyperuricemia (OR: 3.15, 95% CI: 1.61- 6.15, p = 0.001; OR: 4.07, 95% CI: 1.77- 9.33, p = 0.001; OR: 2.81, 95% CI: 1.41- 5.58, p = 0.003 and OR: 2.82, 95% CI: 1.46- 5.45, p = 0.002 respectively). The adjusted logistic regression analysis revealed that only low HDL-cholesterol and glucose intolerance were independent predictors for hyperuricemia (OR: 2.71, 95% CI 1.06- 6.97, p = 0.038; OR: 2.14, 95% CI 1.01- 4.56, p = 0.049, respectively). In our geographical area, the patients with MS showed a nearly 3-fold risk of hyperuricemia than those without. Among all the MS components, low-HDL-cholesterol and high glucose independently increased more than twice the risk of hyperuricemia, and are the pivotal components involved in hyperuricemia.

Effect of losartan combined with amlodipine or with a thiazide on uric acid levels in hypertensive patients

Hyperuricemia leads to endothelial dysfunction and insulin resistance, and has been associated with diseases such as hypertension. Antihypertensive drugs modify serum uric acid levels, however, few data are available about their combinations on uricemia. In this study we evaluate the effect of two combinations of losartan, with amlodipine or with hydrochlorothiazide, on serum uric acid levels in hypertensive patients.

METHODS

A total of 60 hypertensive patients were randomized in two groups; group LA received losartan/amlodipine (100/5 mg) once a day, whereas LH group received losartan hydrochlorothiazide (100/12.5 mg) once a day for 3 months. In both groups serum uric acid levels were measured at the beginning and end of the study. Patients were evaluated monthly for blood pressure (BP) and adverse events. Statistical analysis was performed with a two-way analysis of variance (ANOVA) for repeated measures.

RESULTS

All patients experienced a significant reduction of BP to the same extent (LA 155/94 to 123/79, LH 157/92 to 124/78 mmHg, p > 0.05). In the LA group, serum uric acid decreased from 6.5 ± 1.6 to 4.6 ± 1.3 mg/ml ( p = 0.0001), whereas in the LH group there was a nonsignificant increase from 5.82 ± 1.4 to 5.85 ± 1.5 mg/ml, ( p = 0.936). When both groups were compared, we found a significant reduction ( p < 0.00013) on serum uric acid levels in the LA group.

CONCLUSIONS

Both combinations decrease BP values to the same extent, however, LA combination showed a reduction on serum uric acid levels, which may contribute to a reduction in the metabolic risk in hypertensive patients.

Serum uric acid is independently and linearly associated with risk of nonalcoholic fatty liver disease in obese Chinese adults

The present study aimed to explore the independent association and potential pathways between serum uric acid (SUA) and nonalcoholic fatty liver disease (NAFLD). 1365 community-living obese Chinese adults who received hepatic ultrasonography scanning were included. The prevalence rates of NAFLD were 71.5% for men and 53.8% for women. Compared with controls, NAFLD subjects showed significantly increased SUA levels (333.3 ± 84.9 v.s. 383.4 ± 93.7 μmol/L) and prevalence rate of hyperuricemia (HUA) (25.7% v.s. 47.3%, p < 0.001). After adjustment for insulin resistance (IR), components of metabolic syndrome (MetS) and other potential confounders, elevated SUA is independently associated with increased risk of NAFLD, with the adjusted OR of 1.528–2.031 (p < 0.001). By using multivariable fractional polynomial (MFP) modeling, the best FP transformation model shows that SUA was independently and linearly associated with risk of NAFLD. The one-pathway model by using structural equation modeling (SEM) about the relationships among SUA, IR, components of metabolic syndrome and NAFLD fits well (χ² = 57.367, p < 0.001; CFI = 0.998; TLI = 0.992; and RMSEA = 0.048) and shows SUA might increase the risk of NAFLD directly besides of the indirect effects through increasing fasting insulin, blood pressure, triglyceride and decreasing HDL-C levels. Our results imply that elevated SUA may play an important role in NAFLD pathogenesis.

Evaluation of salivary oxidative parameters in overweight and obese young adults

Background

Obesity is characterized by a deposition of abnormal or excessive fat in adipose tissue, and is linked with a risk of damage to several metabolic and pathological processes associated with oxidative stress. To date, salivary oxidative biomarkers have been minimally explored in obese individuals. Thus, the aim of this study was to assess the concentrations of salivary oxidative biomarkers (ferric-reducing antioxidant power, uric acid, sulfhydryl groups) and lipid peroxidation in obese and overweight young subjects.

Materials and methods

Levels of lipid peroxidation, ferric-reducing antioxidant power, uric acid, and SH groups were determined in the saliva and serum of 149 young adults, including 54 normal weight, 27 overweight, and 68 obese individuals. Anthropometric measurements were also evaluated.

Results

Salivary levels of ferric-reducing antioxidant power, sulfhydryl groups, and lipid peroxidation, as well as serum levels of ferric-reducing antioxidant power, uric acid, and lipid peroxidation were higher in obese patients when compared with individuals with normal weight. There were correlations between salivary and serum ferric-reducing antioxidant power and salivary and serum uric acid in the obese and normal-weight groups.

Conclusions

Our results indicate that the increase in salivary levels of ferric-reducing antioxidant power, sulfhydryl groups, and lipid peroxidation, and serum levels of ferric-reducing antioxidant power, uric acid, and lipid peroxidation could be related to the regulation of various processes in the adipose tissue. These findings may hold promise in identifying new oxidative markers to assist in diagnosing and monitoring overweight and obese patients.

Intestinal Microbiota Distinguish Gout Patients from Healthy Humans

Current blood-based approach for gout diagnosis can be of low sensitivity and hysteretic. Here via a 68-member cohort of 33 healthy and 35 diseased individuals, we reported that the intestinal microbiota of gout patients are highly distinct from healthy individuals in both organismal and functional structures. In gout, Bacteroides caccae and Bacteroides xylanisolvens are enriched yet Faecalibacterium prausnitzii and Bifidobacterium pseudocatenulatum depleted. The established reference microbial gene catalogue for gout revealed disorder in purine degradation and butyric acid biosynthesis in gout patients. In an additional 15-member validation-group, a diagnosis model via 17 gout-associated bacteria reached 88.9% accuracy, higher than the blood-uric-acid based approach. Intestinal microbiota of gout are more similar to those of type-2 diabetes than to liver cirrhosis, whereas depletion of Faecalibacterium prausnitzii and reduced butyrate biosynthesis are shared in each of the metabolic syndromes. Thus the Microbial Index of Gout was proposed as a novel, sensitive and non-invasive strategy for diagnosing gout via fecal microbiota.

Biomarkers of Metabolic Syndrome: Biochemical Background and Clinical Significance

Biomarkers of the metabolic syndrome are divided into four subgroups. Although dividing them in groups has some limitations, it can be used to draw some conclusions. In a first part, the dyslipidemias and markers of oxidative stress are discussed, while inflammatory markers and cardiometabolic biomarkers are reviewed in a second part. For most of them, the biochemical background and clinical significance are discussed, although here also a well-cut separation cannot always be made. Altered levels cannot always be claimed as the cause, risk, or consequence of the syndrome. Several factors are interrelated to each other and act in a concerted, antagonistic, synergistic, or modulating way. Most important conclusions are summarized at the end of every reviewed subgroup. Genetic biomarkers or influences of various food components on concentration levels are not included in this review article.

High serum uric acid levels increase the risk of metabolic syndrome in elderly women: The PRO.V.A study

BACKGROUND AND AIMS

Serum uric acid (SUA) is the end-product of purine metabolism in humans, and its levels often increase in subjects with metabolic syndrome (MetS). Despite several studies demonstrating a relationship between increased SUA levels and the prevalence of MetS, prospective data on SUA as a predictor of the incidence of MetS in the elderly are limited. Our aim was to conduct a prospective study on the association between SUA concentrations and the onset of MetS in an elderly Italian cohort.

METHODS AND RESULTS

This is a cohort study (Progetto Veneto Anziani; Pro.V.A.) involving community-dwelling subjects aged ≥65 years and followed up for a mean 4.4 years. We included 1128 participants (aged 74.7 ± 7.1 years) without MetS at the baseline. Gender-specific SUA groups according to the standard deviation (SD) from the mean were considered, taking the incidence of MetS as the main outcome. The mean SUA level was significantly higher in men than in women (5.4 ± 1.2 vs. 4.5 ± 1.2 mg/dl; p < 0.0001). Over the 4.4-year follow-up, 496 individuals developed MetS. After adjusting for potential confounders, Cox's regression analysis revealed no relationship between higher baseline SUA concentrations and the incidence of MetS in men or in the sample as whole, while women with SUA levels more than 1 SD above the mean (≥5.7 mg/dl) carried a 58% higher risk (95%CI: 1.03-2.40; p = 0.03) of being newly diagnosed with MetS during the follow-up.

CONCLUSION

High SUA levels significantly and independently predicted MetS in older women, but not in men, over a 4.4-year follow-up.

Chronic Glucocorticoid-Rich Milieu and Liver Dysfunction

We investigated the impact of chronic hypercorticosteronemia (due to neonatal monosodium L-glutamate, MSG, and treatment) on liver oxidative stress (OS), inflammation, and carbohydrate/lipid metabolism in adult male rats. We evaluated the peripheral concentrations of several metabolic and OS markers and insulin resistance indexes. In liver we assessed (a) OS (GSH and protein carbonyl groups) and inflammatory (IL-1b, TNFa, and PAI-1) biomarkers and (b) carbohydrate and lipid metabolisms. MSG rats displayed degenerated optic nerves, hypophagia, low body and liver weights, and enlarged adipose tissue mass; higher peripheral levels of glucose, triglycerides, insulin, uric acid, leptin, corticosterone, transaminases and TBARS, and peripheral and liver insulin resistance; elevated liver OS, inflammation markers, and glucokinase (mRNA/activity) and fructokinase (mRNA). Additionally, MSG liver phosphofructokinase-2, glucose-6-phosphatase (mRNA and activity) and glucose-6-phosphate dehydrogenase, Chrebp, Srebp1c, fatty acid synthase, and glycerol-3-phosphate (mRNAs) were increased. In conclusion adult MSG rats developed an insulin-resistant state and increased OS and serious hepatic dysfunction characterized by inflammation and metabolic signs suggesting increased lipogenesis. These features, shared by both metabolic and Cushing's syndrome human phenotypes, support that a chronic glucocorticoid-rich endogenous environment mainly impacts on hepatic glucose cycle, displacing local metabolism to lipogenesis. Whether correcting the glucocorticoid-rich environment ameliorates such dysfunctions requires further investigation.

Systematic Review of Metabolic Syndrome Biomarkers: A Panel for Early Detection, Management, and Risk Stratification in the West Virginian Population

INTRODUCTION

Metabolic syndrome represents a cluster of related metabolic abnormalities, including central obesity, hypertension, dyslipidemia, hyperglycemia, and insulin resistance, with central obesity and insulin resistance in particular recognized as causative factors. These metabolic derangements present significant risk factors for cardiovascular disease, which is commonly recognized as the primary clinical outcome, although other outcomes are possible. Metabolic syndrome is a progressive condition that encompasses a wide array of disorders with specific metabolic abnormalities presenting at different times. These abnormalities can be detected and monitored via serum biomarkers. This review will compile a list of promising biomarkers that are associated with metabolic syndrome and this panel can aid in early detection and management of metabolic syndrome in high risk populations, such as in West Virginia.

METHODS

A literature review was conducted using PubMed, Science Direct, and Google Scholar to search for markers related to metabolic syndrome. Biomarkers searched included adipokines (leptin, adiponectin), neuropeptides (ghrelin), pro-inflammatory cytokines (IL-6, TNF-α), anti-inflammatory cytokines (IL-10), markers of antioxidant status (OxLDL, PON-1, uric acid), and prothrombic factors (PAI-1).

RESULTS

According to the literature, the concentrations of pro-inflammatory cytokines (IL-6, TNF-α), markers of pro-oxidant status (OxLDL, uric acid), and prothrombic factors (PAI-1) were elevated in metabolic syndrome. Additionally, leptin concentrations were found to be elevated in metabolic syndrome as well, likely due to leptin resistance. In contrast, concentrations of anti-inflammatory cytokines (IL-10), ghrelin, adiponectin, and antioxidant factors (PON-1) were decreased in metabolic syndrome, and these decreases also correlated with specific disorders within the cluster.

CONCLUSION

Based on the evidence presented within the literature, the aforementioned biomarkers correlate significantly with metabolic syndrome and could provide a minimally-invasive means for early detection and specific treatment of these disorders. Further research is encouraged to determine the efficacy of applying these biomarkers to diagnosis and treatment in a clinical setting.

Prevalence of Metabolic Syndrome and Insulin Resistance in Children and Adolescent of Qazvin, Iran

BACKGROUND

The prevalence of metabolic syndrome (MetSyn) is increasing worldwide. The aim of this study was to determine the prevalence of MetSyn and insulin resistance (IR) in children and adolescents in Qazvin, Iran.

METHODS

A cross-sectional study was conducted in 338 children and adolescents aged 10-18 years old who were selected by a multistage cluster random sampling method. We performed standardised measurements of variables including waist circumference (WC), blood pressure, plasma glucose level, total cholesterol, high-density lipoprotein cholesterol (HDL), triglycerides, and insulin. MetSyn was defined according to the International Diabetes Federation criteria. IR was estimated by the homeostatic model assessment.

RESULTS

Of the 338 total subjects, 172 were female. The overall prevalence of MetSyn and IR were 3.4% and 18.2%, respectively. There was no sex difference for the prevalence of MetSyn. A total of 185 subjects (56.4%) had one or two components of MetSyn. The most common component was low HDL levels in both sexes, which was followed by high WC in females and high fasting plasma glucose levels in males.

CONCLUSION

The lack of a standard definition of MetSyn in children and adolescents combined with the geographical and socioeconomic differences make it difficult to compare the results from different studies. Modification of lifestyle habits is an important strategy in preventing MetSyn and IR.

[Hyperuricaemia and metabolic syndrome in obese children and adolescents]

INTRODUCTION

Hyperuricaemia has been suggested as an additional metabolic factor in adult obese patients, but it has not been sufficiently studied in paediatric.

OBJECTIVES

To assess the relationship between serum uric acid levels (SUAL) with the level of general and visceral obesity, and other biochemical parameters in children and adolescents of Santiago, Chile.

SUBJECTS AND METHOD

A cross sectional study was conducted on 770 children and adolescents (ages: 6-15 y.) from a public school in Santiago, Chile, of whom 227 (29%) were obese (BMI>2 SD, WHO growth standards). Ninety subjects were randomly selected and 77 with no other chronic disease (41 males) accepted to participate. Data was collected on weight, stature, abdominal circumference (AC), visceral adiposity using ultrasound, and other biochemical measurements including fasting glucose, insulin, serum lipids, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and SUAL.

RESULTS

The mean SUAL was 0.200±0.065 mmol/L, and was increased in children with hyperinsulinism (adjusted by age: 0.221±0.075 vs. 0.183±0.054 mmol/L; P<.01), with no significant differences according to HOMA. Differences were also found between children with ALT>or<26 U/mL: 0.238±0.070 vs. 0.178±0.054 mmol/L, P<.001. The logistic regression showed the increased SUAL was only associated with increased ALT. No significant differences were found in general or visceral adiposity measurements or fatty liver.

CONCLUSIONS

Children and adolescents from Santiago, Chile have higher uric acid serum uric acid levels as well as an association with increased ALT and insulin. It is demonstrated in this study that uric acid should be measured in obese children and adolescents, and in their follow up.

Serum uric acid: a new therapeutic target for nonalcoholic fatty liver disease

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is a major, worldwide public health problem. NAFLD is recognized as a major cause of liver-related morbidity and mortality. However, physicians are currently limited by available treatment options. Recently, numerous studies have reported a correlation between serum uric acid (SUA) and NAFLD with numerous clinical and experimental studies demonstrating a significant correlation. This review will focus on the role of SUA in the development of NAFLD and its potential role as a new target for therapeutic intervention.

AREAS COVERED

This review discusses SUA as a significant independent factor in the development of NAFLD. Moreover, we introduce the causal relationship between SUA, metabolic syndrome, and NAFLD. We discuss two major theories of insulin resistance and inflammasomes as potential explanations of the mechanistic link between SUA and NAFLD. In addition, we review current and emerging therapeutic medications to control appropriate SUA levels.

EXPERT OPINION

There is an urgent need to develop novel, safe and effective therapies for the growing NAFLD epidemic. Reduction of SUA may be a promising potential treatment for patients with NAFLD. Clinical studies are required to determine the therapeutic effect of attenuation of hyperuricemia in humans with NAFLD.

Dose-response Relationship of Serum Uric Acid with Metabolic Syndrome and Non-alcoholic Fatty Liver Disease Incidence: A Meta-analysis of Prospective Studies

Emerging evidence has shown that serum uric acid (SUA) elevation might cause metabolic derangements, including metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD); however, magnitude of the risk has not been quantified. We searched PubMed, EMBASE, and ISI databases for relevant studies through 10 May 2015. Prospective studies reporting the risk of SUA elevation on the incidence of MetS/NAFLD were enrolled. Pooled HR of MetS was 1.55 (95%CI: 1.40-1.70) for the highest versus lowest SUA categories, and 1.05 (95%CI: 1.04-1.07) per incremental increased in SUA of 1 mg/dl. The pooled HR of MetS in younger women was higher than age-matched men and older women (1.17 vs. 1.05 and 1.04, respectively, P < 0.05). Individuals in the highest SUA category had a 40% greater risk of disease NAFLD occurrence. Dose-response increment of NAFLD events was 1.03 (95%CI: 1.02-1.05). A positive relationship with a linear trend for SUA elevation with MetS and NAFLD in different genders was examined by a dose-response meta-analysis (P < 0.001).SUA assay is useful in screening metabolic disorders for linear trend between its elevation and MetS/NAFLD incidence. SUA-lowering therapy is a potential strategy for preventing systemic/hepatic metabolic abnormalities.

Higher blood hematocrit predicts hyperuricemia: a prospective study of 62,897 person-years of follow-up

This prospective study aimed to investigate the relationship between higher hematocrit (Hct) level and hyperuricemia (HU) incidence. A total of 27,540 subjects were included. Baseline Hct was classified into four categories based on the quartile distribution of the study population. A cox proportional hazards regression was used to evaluate the risk of HU incidence across the Hct quartiles after adjusting a number of potential confounding factors. Out of the 62,897 person-years of follow-up, 2745 new cases of HU were developed. In models adjusted for known risk factors of HU, higher Hct was used to predict HU incidence independently in a graded manner (p = 0.02): compared with subjects in the lowest quartile, subjects in the highest quartile of Hct (hazard ratio = 1.20; 95% confidence interval: 1.03-1.41) were n20% more likely to develop HU. Sensitivity analysis indicated that the hazard ratios increased with the extension of the minimum follow-up interval. When the minimum follow-up interval was restricted to 4 years, subjects in the highest quartile of Hct were 70% more likely to develop HU, compared with the lowest quartile. Higher Hct, a routinely measured inexpensive biomarker was independently associated with the incidence of HU even within the normal range.

Risk Factors of Bone Mass Loss at the Lumbar Spine: A Longitudinal Study in Healthy Korean Pre- and Perimenopausal Women Older than 40 Years

Longitudinal studies on bone mass decline for healthy women are sparse. We performed a retrospective longitudinal study to evaluate the factor associated with bone mass changes at the lumbar spine in healthy Korean pre- and perimenopausal women over the age of 40. We examined the relation of blood tests including thyroid function tests at baseline and follow-up to the annual percentage changes in average BMD of L2-L4 (A%ΔLSBMD). Four hundred and forty-three subjects without diseases or medications pertaining to bone metabolism were analyzed. The mean A%ΔLSBMD in these subjects was -0.45%/year. Though a significant correlation was observed between the A%ΔLSBMD and age, serum thyroid-stimulating hormone (TSH) level, total cholesterol (TC) level, low-density lipoprotein cholesterol (LDL-C) level, and estimated glomerular filtration rate (eGFR) at baseline and follow-up, there was a weak correlation between A%ΔLSBMD and these variables. From multiple linear regression analyses, the percent body fat, age, serum TSH level, serum uric acid level, and the menopause at follow-up were showed to have a significant association with the A%ΔLSBMD. Unlike age, percent body fat, and menopause at follow-up, which had a negative association with the A%ΔLSBMD, serum TSH level and serum uric acid level, had a positive association with the A%ΔLSBMD. The results from our study showed that the notable risk factors of BMD loss at the lumbar spine in population of our study were advancing age, menopause, higher percent body fat, lower normal TSH, and lower serum uric acid levels.

A Mendelian Randomization Study of Circulating Uric Acid and Type 2 Diabetes

We aimed to investigate the causal effect of circulating uric acid concentrations on type 2 diabetes risk. A Mendelian randomization study was performed using a genetic score with 24 uric acid-associated loci. We used data of the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study, comprising 24,265 individuals of European ancestry from eight European countries. During a mean (SD) follow-up of 10 (4) years, 10,576 verified incident case subjects with type 2 diabetes were ascertained. Higher uric acid was associated with a higher diabetes risk after adjustment for confounders, with a hazard ratio (HR) of 1.20 (95% CI 1.11, 1.30) per 59.48 µmol/L (1 mg/dL) uric acid. The genetic score raised uric acid by 17 µmol/L (95% CI 15, 18) per SD increase and explained 4% of uric acid variation. By using the genetic score to estimate the unconfounded effect, we found that a 59.48 µmol/L higher uric acid concentration did not have a causal effect on diabetes (HR 1.01 [95% CI 0.87, 1.16]). Including data from the Diabetes Genetics Replication And Meta-analysis (DIAGRAM) consortium, increasing our dataset to 41,508 case subjects with diabetes, the summary odds ratio estimate was 0.99 (95% CI 0.92, 1.06). In conclusion, our study does not support a causal effect of circulating uric acid on diabetes risk. Uric acid-lowering therapies may therefore not be beneficial in reducing diabetes risk.

Resolution of non-alcoholic steatohepatitis by rosuvastatin monotherapy in patients with metabolic syndrome

AIM: To investigate the effect of rosuvastatin monotherapy on non-alcoholic steatohepatitis (NASH). At present there is no effective treatment for non-alcoholic fatty liver disease or its advanced form NASH.

METHODS: This prospective study included 20 biopsy proven patients with NASH, metabolic syndrome (MetS) and dyslipidaemia. Biochemical parameters of the blood of the patients and an ultrasonography of the liver were performed at baseline. Then patients received lifestyle advice and were treated for a 12 mo period with rosuvastatin (10 mg/d) monotherapy. Patients were re-evaluated during the study at 3 mo intervals, during which biochemical parameters of the blood were measured including liver enzymes. A repeat biopsy and ultrasonography of the liver were performed at the end of the study in all 20 patients. Changes in liver enzymes, fasting plasma glucose, serum creatinine, serum uric acid (SUA), high sensitivity C reactive protein (hsCRP) and lipid profile were assessed every 3 mo. The primary endpoint was the resolution of NASH and the secondary endpoints were the changes in liver enzyme and lipid values.

RESULTS: The repeat liver biopsy and ultrasonography showed complete resolution of NASH in 19 patients, while the 20^th, which had no improvement but no deterioration either, developed arterial hypertension and substantial rise in triglyceride levels during the study, probably due to changes in lifestyle including alcohol abuse. Serum alanine transaminase, aspartate transaminase, and γ-glutamyl transpeptidase were normalised by the 3^rd treatment month (ANOVA P < 0.001), while alkaline phosphatase activities by the 6^th treatment month (ANOVA, P = 0.01). Fasting plasma glucose and glycated haemoglobin were significantly reduced (P < 0.001). Lipid values were normalised by the 3^rd treatment month. No patient had MetS by the 9^th treatment month. Body mass index and waist circumference remained unchanged during the study. Thus, changes in liver pathology and function should be attributed solely to rosuvastatin treatment. A limitation of the study is the absence of a control group.

CONCLUSION: These findings suggest that rosuvastatin monotherapy could ameliorate biopsy proven NASH and resolve MetS within 12 mo. These effects and the reduction of fasting plasma glucose and SUA levels may reduce the risk of vascular and liver morbidity and mortality in NASH patients. These findings need confirmation in larger studies.

The xanthine oxidase inhibitor febuxostat suppresses development of nonalcoholic steatohepatitis in a rodent model

Xanthine oxidase (XO) is an enzyme involved in the production of uric acid (UA) from purine nucleotides. Numerous recent studies have revealed the likelihood of metabolic syndrome including nonalcoholic fatty liver disease (NAFLD) or steatohepatitis (NASH) to be related to hyperuricemia. However, it remains unclear whether elevated serum UA during the development of NAFLD or NASH is a cause or a consequence of these diseases. In this study, the XO inhibitor febuxostat was administered to two types of NASH model mice. Febuxostat exerted a strong protective effect against NASH development induced by a high-fat diet containing trans fatty acid (HFDT). In contrast, methionine choline-deficient-diet-induced NASH development not accompanied by hyperuricemia showed no UA normalization, suggesting that the ameliorating effect of febuxostat occurs via the normalization of hyperuricemia itself and/or accompanying molecular mechanism(s) such as oxidative stress. In the HFDT-fed mice, hyperuricemia, elevated alanine aminotransferase, and increased Tunnel-positive cells in the liver were normalized by febuxostat administration. In addition, upregulation of fatty acid oxidation-related genes, fibrotic change, and increases in collagen deposition, inflammatory cytokine expressions, and lipid peroxidation in the HFDT-fed mice were also normalized by febuxostat administration. Taken together, these observations indicate that administration of febuxostat has a protective effect against HFDT-induced NASH development, suggesting the importance of XO in its pathogenesis. Thus XO inhibitors are potentially potent therapies for patients with NASH, particularly that associated with hyperuricemia.

Statins can improve proteinuria and glomerular filtration rate loss in chronic kidney disease patients, further reducing cardiovascular risk. Fact or fiction?

INTRODUCTION

The prevalence of chronic kidney disease (CKD), a risk factor for cardiovascular disease (CVD), is increasing worldwide. Statin treatment, the cornerstone of prevention or treatment of CVD, might have beneficial effects on urine protein excretion and renal function as determined by the glomerular filtration rate, whereas it might protect from acute kidney injury (AKI), mainly due to contrast-induced AKI. These beneficial effects on CKD may not be drug class effects; specific statins at specific doses may help prevent CKD deterioration and reduce CVD risk. We analysed all statin studies that had renal and CVD endpoints as main outcome measures. MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched up to February 2015.

AREAS COVERED

We consider the effects of statins on microalbuminuria, proteinuria, glomerular filtration rate, AKI associated with angiography or percutaneous coronary intervention and on CVD event rates in patients with CKD.

EXPERT OPINION

Current evidence points towards the need to prescribe high-potency statins in patients with CKD, before a major decline in kidney function occurs. This may reduce CVD risk and delay the progress of CKD. Administration of either atorvastatin or rosuvastatin can prevent contrast-induced AKI before angiography or percutaneous coronary intervention. The combination of simvastatin + ezetimibe may decrease vascular events in patients with advanced CKD.

Relation between uric acid and metabolic syndrome in subjects with cardiometabolic risk

Objective

To identify possible relations between serum uric acid levels and metabolic syndrome and its components in a population with cardiometabolic risk.

Methods

This cross-sectional study included 80 subjects (46 women), with mean age of 48±16 years, seen at the Cardiovascular Health Program.

Results

The prevalence of hyperuricemia and metabolic syndrome was 6.3% and 47.1%, respectively. Uric acid level was significantly higher in individuals with metabolic syndrome (5.1±1.6mg/dL), as compared to those with no syndrome or with pre-syndrome (3.9±1.2 and 4.1±1.3mg/dL, respectively; p<0.05). The uric acid levels were significantly higher in men presenting abdominal obesity, and among women with abdominal obesity, lower HDL-c levels and higher blood pressure (p<0.05).

Conclusion

Uric acid concentrations were positively related to the occurrence of metabolic syndrome and its components, and there were differences between genders. Our results indicate serum uric acid as a potential biomarker for patients with cardiometabolic risk.

Are uric acid plasma levels different between unipolar depression with and without adult attention deficit hyperactivity disorder?

BACKGROUND

The aim of our study is to compare uric acid plasma levels in patients with unipolar depression between those with Attention deficit hyperactivity disorder (ADHD) comorbidity and those without. Our hypothesis is that uric acid plasma levels may be higher in unipolar depressive patients with adult ADHD than without ADHD.

METHODS

Sixty four patients diagnosed with MDD were investigated, among which 28 patients had been diagnosed with ADHD according to DSM5. 28 patients were ADHD. 36 patients were diagnosed as not having ADHD. One of the criteria was including cases that had not started using medication for the current depressive episode. The control group (HC) consisted of 43 healthy staff members from our hospital who had no prior psychiatric admission or treatment history and matched with the patient group in terms of age and gender. Blood samples were obtained, and plasma uric acid levels were recorded in mg/dl after being rotated for 15min in a centrifuge with 3000 rotations and kept at -80°C.

RESULTS

Uric acid plasma levels 5.1±1.6 in unipolar depression and ADHD group, 4.6±1.8 in unipolar depression group. Uric acid plasma levels were higher in the comorbid unipolar depression and ADHD group than in the unipolar depression and healthy control (HC) groups (F= 4.367, p= 0.037). There was no correlation between ADHD (predominantly inattentive type) and uric acid plasma levels (p>0.05).

LIMITATIONS

The limitation of this study is the small number of sample and one of the criteria was including cases that had not started using medication for the current depressive episode.

CONCLUSION

The identification of a different etiologic process of biological markers may lead to a better understanding of the physiological mechanisms involved in drive and impulsivity and may suggest different potential targets for therapeutic intervention.

Serum uric acid concentrations and SLC2A9 genetic variation in Hispanic children: the Viva La Familia Study

BACKGROUND

Elevated concentrations of serum uric acid are associated with increased risk of gout and renal and cardiovascular diseases. Genetic studies in adults have consistently identified associations of solute carrier family 2, member 9 (SLC2A9), polymorphisms with variation in serum uric acid. However, it is not known whether the association of serum uric acid with SLC2A9 polymorphisms manifests in children.

OBJECTIVE

The aim was to investigate whether variation in serum uric acid is under genetic influence and whether the association with SLC2A9 polymorphisms generalizes to Hispanic children of the Viva La Familia Study.

DESIGN

We conducted a genomewide association study with 1.1 million genetic markers in 815 children.

RESULTS

We found serum uric acid to be significantly heritable [h(2) ± SD = 0.45 ± 0.08, P = 5.8 × 10(-11)] and associated with SLC2A9 variants (P values between 10(-16) and 10(-7)). Several of the significantly associated polymorphisms were previously identified in studies in adults. We also found positive genetic correlations between serum uric acid and BMI z score (ρG = 0.45, P = 0.002), percentage of body fat (ρG = 0.28, P = 0.04), fat mass (ρG = 0.34, P = 0.02), waist circumference (ρG = 0.42, P = 0.003), and waist-to-height ratio (ρG = 0.46, P = 0.001).

CONCLUSIONS

Our results show that variation in serum uric acid in Hispanic children is under considerable genetic influence and is associated with obesity-related phenotypes. As in adults, genetic variation in SLC2A9 is associated with serum uric acid concentrations, an important biomarker of renal and cardiovascular disease risk, in Hispanic children.

Mid-gestational serum uric acid concentration effect on neonate birth weight and insulin resistance in pregnant women

Objective

To investigate the relationship between mid-gestational serum uric acid and birth weight in diabetic pregnant women with or without insulin resistance.

Methods:

In a prospective cohort study, fasting uric acid, blood glucose, and serum insulin were measured in 247 pregnant women between 20-22 weeks of gestational period. Insulin resistance was estimated using the homeostasis model assessment-insulin resistance (HOMA-IR). Stratification analysis and independent t-test was used to assess the association between uric acid and birth weights regarding to insulin resistance.

Results:

The means of the mid-gestational serum uric acid concentrations were not significantly different in women with and without insulin resistance. But stratification analysis showed that there was a significant difference between uric acid concentration and macrosomic birth in diabetic women without insulin resistance.

Conclusions:

Higher mid – gestation serum uric acid concentration, even if it does not exceed the normal range, is accompanied by lower birth weight only in non-insulin resistance women. Insulin resistance could have a negative confounding effect on hyperuriemia and birth weight.

Dapagliflozin in patients with type 2 diabetes mellitus

Dapagliflozin is a selective and reversible inhibitor of sodium-glucose linked transporter type 2 (SGLT2), which mediates approximately 90% of active renal glucose reabsorption in the early proximal tubule of the kidney. Dapagliflozin significantly reduces glucose reabsorption and decreases serum glucose concentration in an insulin-independent manner. The decrease of glucose reabsorption by dapagliflozin has also been associated with a reduction in body weight. Furthermore, the drug modestly reduces blood pressure levels through weight loss and its action as osmotic diuretic. Dapagliflozin has been approved as monotherapy in patients with type 2 diabetes mellitus (T2DM) who cannot tolerate metformin or in combination with other antidiabetic drugs, with the exception of pioglitazone due to the theoretical increased risk of bladder cancer. The drug should not be prescribed in patients with moderate or severe renal impairment or in patients at risk for developing volume depletion. Dapagliflozin is associated with increased incidence of genital and lower urinary tract infections, but these infections are usually mild to moderate and respond to standard antimicrobial treatment. Based on current evidence, dapagliflozin is a useful drug for patients with T2DM with a favorable safety profile. However, further research regarding the effects of dapagliflozin on cardiovascular outcomes is needed.

Does obesity or hyperuricemia influence lithogenic risk profile in children with urolithiasis?

BACKGROUND

There are indications that obesity and hyperuricemia may influence the formation and composition of urinary stones. The aim of our study was to determine the effect of obesity and hyperuricemia on the urinary lithogenic risk profile in a large cohort of pediatric patients.

METHODS

The study population comprised 478 children with urolithiasis and 517 healthy children (reference group). We studied the effects of obesity on the lithogenic profile by dividing the patients with urolithiasis into two groups based on body mass index Z-score (patients who were overweight/obese vs. those with normal weight for age) and comparing the two groups. To study the effect of hyperuricemia on the lithogenic profile, we divided the patients with urolithiasis into two groups based on the presence or not of hyperuricemia (110 patients with urolithiasis accompanied by hyperuricemia vs. 368 patients with urolithiasis and normal serum uric acid levels) and compared the groups.

RESULTS

Among the children and adolescents with urolithiasis and hyperuricemia, there was a significantly lower excretion of crystallization inhibitors (citrates, magnesium). We also found significantly negative correlations between serum uric acid levels and the urine citrate/creatinine ratio (citrate/cr.; r = -0.30, p < 0.01), as well as the magnesium/cr. ratio (Mg/cr.; r = -0.33, p < 0.01). There was no statistically significant differences in the urinary excretion of oxalates, citrates, calcium, phosphorus, magnesium and uric acid between children with urolithiasis who were either overweight or obese and children with urolithiasis who had a normal body weight.

CONCLUSIONS

In our pediatric patient cohort, hyperuricemia was associated with a decrease in the excretion of crystallization inhibitors in the urine, but the clinical relevance of this observation needs to be confirmed in future studies. Obesity and overweight had no direct influence on the lithogenic risk profile in the urinary stone formers in our study, but there was an indication that higher serum uric acid may be associated with impairment in renal function, which in turn could influence the excretion of lithogenic parameters.

Serum gamma-glutamyl transferase is associated with the elevated uric acid levels in normotensive Chinese adults

BACKGROUND

Although both serum gamma-glutamyltransferase (GGT) and uric acid are correlated with hypertension, studies on the association between serum GGT and uric acid in normotensive individuals are rare. In this study, we tried to reveal this relationship in normotensive Chinese adults.

METHODS

Four hundred seven normotensive adults were recruited. The subjects were divided into 3 subgroups according to serum GGT tertiles. Anthropometric parameters as well as systolic blood pressure (SBP), diastolic blood pressure (DBP), uric acid, GGT, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood glucose, blood lipids, and fasting insulin were measured. Insulin resistance was assessed using HOMA-IR index.

RESULTS

Uric acid was increased in parallel with increasing serum GGT (P<0.001). After correction for age, sex, smoking and alcohol consumption, serum GGT was positively associated with uric acid (r=0.42, P<0.001), SBP (r=0.22, P<0.001), and DBP (r=0.19, P<0.001). When compared with lowest GGT tertile, the odds ratio of the middle tertile for the increased serum uric acid was 3.43 (95% CI, 1.39-8.47) and 7.29 (95% CI, 1.57-33.82) for the highest tertile after adjustment for age, sex, BMI, smoking, alcohol consumption, SBP, DBP, creatinine and HOMA-IR.

CONCLUSIONS

Serum GGT is strongly associated with the increased uric acid concentrations in normotensive Chinese adults.

The Association between Serum Uric Acid Level and Incidence of Metabolic Syndrome according to Menopausal Status in Korean Women

Objectives

The aim of this study is to investigate the association between serum uric acid level and metabolic syndrome according to menopausal status in Korean women.

Methods

A total of 2,241 women who visited to the health promotion center at Pusan National University Hospital from 2010 to 2014 were included in this cross-sectional study. Self-report questionnaires and interviews with healthcare providers were used to assess disease history, medication history, menstrual history and body size measuring. Anthropometric measurements and laboratory results were compared as presence of metabolic syndrome and menopausal status by student-t test. Logistic regression analysis was performed between presence of metabolic syndrome and presumable predictive factors, such as age, menopause and serum uric acid.

Results

The prevalence rate of metabolic syndrome were 7.45% (63/846) in pre-menopausal group and 23.87% (333/1395) in menopausal group. Serum uric acid level was higher in menopausal women than premenopausal women (4.6 ± 1.1 vs. 4.3 ± 0.9. P = 0.000). And, its concentration was also higher in metabolic syndrome than normal women regarding of menopausal statue (premenopause 4.7 ± 1.1 vs. 4.2 ± 0.8, P = 0.001, menopause 4.9 ± 1.3 vs. 4.5 ± 1.0, P = 0.000). Multiple logistic regression analysis showed serum uric acid and age have relationship with metabolic syndrome (OR: 1.453, 95% confidence interval [CI]: 1.074-1.111, P = 0.000; OR: 1.092, 95% CI: 1.305-1.619, P = 0.000).

Conclusion

We could find out some potential of uric acid as predictive factor for metabolic syndrome in premenopausal and menopausal group. Further investigation is required to clarify the relationship between serum uric acid, menopause and metabolic syndrome.

Linking uric acid metabolism to diabetic complications

Hyperuricemia have been thought to be caused by the ingestion of large amounts of purines, and prevention or treatment of hyperuricemia has intended to prevent gout. Xanthine dehydrogenase/xanthine oxidase (XDH/XO) is rate-limiting enzyme of uric acid generation, and allopurinol was developed as a uric acid (UA) generation inhibitor in the 1950s and has been routinely used for gout prevention since then. Serum UA levels are an important risk factor of disease progression for various diseases, including those related to lifestyle. Recently, other UA generation inhibitors such as febuxostat and topiroxostat were launched. The emergence of these novel medications has promoted new research in the field. Lifestyle-related diseases, such as metabolic syndrome or type 2 diabetes mellitus, often have a common pathological foundation. As such, hyperuricemia is often present among these patients. Many in vitro and animal studies have implicated inflammation and oxidative stress in UA metabolism and vascular injury because XDH/XO act as one of the major source of reactive oxygen species Many studies on UA levels and associated diseases implicate involvement of UA generation in disease onset and/or progression. Interventional studies for UA generation, not UA excretion revealed XDH/XO can be the therapeutic target for vascular injury and renal dysfunction. In this review, the relationship between UA metabolism and diabetic complications is highlighted.

Resistance Training in Type 2 Diabetic Patients Improves Uric Acid levels

Resistance training (RT) can provide several benefits for individuals with Type 2 diabetes. The aim of this study was to investigate the effects of resistance training on the strength levels and uric acid (UA) concentration in individuals with Type 2 diabetes. The study included 68 patients (57.7±9.0 years) that participated in an organized program of RT for 12 weeks. The volunteers were divided into two groups: an experimental group (EG; n=34) that performed the resistance training program consisting of seven exercises executed in an alternating order based on segments; and a control group (CG; n=34) that maintained their normal daily life activities. Muscle strength and uric acid were measured both pre- and post-experiment. The results showed a significant increase in strength of the subjects in the EG for all exercises included in the study (p<0.001). Comparing the strength levels of the post-test, intergroup differences were found in supine sitting (p<0.001), leg extension (p<0.001), shoulder press (p<0.001), leg curl (p=0.001), seated row (p<0.001), leg press (p=0.001) and high pulley (p<0.001). The measured uric acid was significantly increased in both experimental and control groups (p<0.001 and p=0.001, respectively). The intergroup comparison showed a significant increase for the EG (p=0.024). We conclude that the training program was effective for strength gains despite an increase in uric acid in Type 2 diabetics.

Serum glycated albumin, but not glycated hemoglobin, is low in relation to glycemia in men with hypertriglyceridemia

Aims/Introduction:  Serum glycated albumin (GA) and glycated hemoglobin (HbA1c) are influenced by plasma glucose levels, and are used for monitoring chronic glycemic control in diabetic patients. Both glycated proteins are known to be influenced by various factors other than plasma glucose levels. In the present study, we examined the effects of hypertriglyceridemia on them.

MATERIALS AND METHODS

  The present study comprised 273 non-diabetic men. They were grouped into men with normotriglyceridemia (serum triglyceride [TG] <150 mg/dL) and those with hypertriglyceridemia (serum TG ≥150 mg/dL).

RESULTS

  Body mass index (BMI) and high sensitivity C-reactive protein (hs-CRP) were significantly higher in the 160 men with hypertriglyceridemia than the 113 men with normotriglyceridemia. In men with hypertriglyceridemia, as compared with those with normotriglyceridemia, fasting plasma glucose, 2-h plasma glucose after 75 g oral glucose tolerance test, and HbA1c were significantly higher. By contrast, serum GA was significantly lower in men with hypertriglyceridemia. BMI-adjusted serum GA was also significantly lower in these men. In a multivariate analysis, serum TG was an inverse explanatory variable for serum GA.

CONCLUSIONS

  Serum GA is low in relation to plasma glucose levels in men with hypertriglyceridemia. This might be caused by increased albumin metabolism associated with hypertriglyceridemic state. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2010.00049.x, 2010).

Serum uric acid and target organ damage in essential hypertension

Background

Hypertension is a major risk factor for cardiovascular mortality, as it acts through its effects on target organs, such as the heart and kidneys. Hyperuricemia increases cardiovascular risk in patients with hypertension.

Objective

To assess the relationship between serum uric acid and target organ damage (left ventricular hypertrophy and microalbuminuria) in untreated patients with essential hypertension.

Patients and methods: A cross-sectional study was carried out in 130 (85 females, 45 males) newly diagnosed, untreated patients with essential hypertension. Sixty-five healthy age- and sex-matched non-hypertensive individuals served as controls for comparison. Left ventricular hypertrophy was evaluated by cardiac ultrasound scan, and microalbuminuria was assessed in an early morning midstream urine sample by immunoturbidimetry. Blood samples were collected for assessing uric acid levels.

Results

Mean serum uric acid was significantly higher among the patients with hypertension (379.7±109.2 μmol/L) than in the controls (296.9±89.8 μmol/L; P<0.001), and the prevalence of hyperuricemia was 46.9% among the hypertensive patients and 16.9% among the controls (P<0.001). Among the hypertensive patients, microalbuminuria was present in 54.1% of those with hyperuricemia and in 24.6% of those with normal uric acid levels (P=0.001). Similarly, left ventricular hypertrophy was more common in the hypertensive patients with hyperuricemia (70.5% versus 42.0%, respectively; P=0.001). There was a significant linear relationship between mean uric acid levels and the number of target organ damage (none versus one versus two: P=0.012).

Conclusion

These results indicate that serum uric acid is associated with target organ damage in patients with hypertension, even at the time of diagnosis; thus, it is a reliable marker of cardiovascular damage in our patient population.

The association between serum uric acid and residual β -cell function in type 2 diabetes

The aim of this study was to investigate the relationship of serum uric acid (sUA) with residual β -cell function in type 2 diabetes. Oral glucose tolerance tests (OGTT) were performed on 1021 type 2 diabetes patients. The ratio of area under curve of insulin to glucose during 0 to 30 min and 0 to 120 min of the OGTT was calculated as indices of insulin secretion function. The products of insulin secretion indices multiplied by Matsuda insulin sensitivity index were used as disposition indices. After correlation and multiple linear regression analysis, sUA was significantly associated with insulin secretion and disposition indices in male, female, and total groups adjusted for confounding factors (including metabolic indicators like sex, age, course of the disease, blood glucose, blood pressure, serum lipids, and so on). Superficially steeper time-dependent decline of insulin secretion function was found in patients with sUA above the median than those below it. In conclusion, our results suggest an independent positive association between sUA and residual β -cell function in type 2 diabetes. Patients with higher sUA have greater insulin secretion ability than those with lower sUA at the early stage of disease, but their residual β -cell function seems to decay more rapidly.

Hyperuricemia predicts future metabolic syndrome: a 4-year follow-up study of a large screened cohort in Okinawa, Japan

The aim of this study was to determine whether hyperuricemia could predict future metabolic syndrome (MetS) in a large screened cohort of Japanese male and female subjects. We evaluated 5936 subjects (3144 male subjects, 2792 female subjects; mean age 48.7 years) who underwent health checkup programs in 2006 and 2010, who were MetS free in 2006. At baseline, hyperuricemia was detected in 927 male subjects (29.5%) and 276 female subjects (9.9%). Subjects with baseline hyperuricemia had significantly higher MetS prevalence in 2010 than those without (male subjects: 34.8 vs. 20.6%, P<0.0001; female subjects: 15.6 vs. 4.8%, P<0.0001). Compared with subjects in the first quintile of uric acid levels at baseline, the age-adjusted odds ratios (ORs) for MetS cumulative incidence among subjects in the third, fourth and fifth quintiles were, 1.8 (95% confidence interval (CI): 1.4-2.4: P<0.0001), 2.1 (95% CI: 1.6-2.8: P<0.0001) and 3.2 (95% CI: 2.4-4.1: P<0.0001), respectively, for male subjects and 2.4 (95% CI: 1.3-4.7: P=0.0075), 3.0 (95% CI: 1.6-5.7: P=0.0010) and 4.8 (95% CI: 2.6-8.8: P<0.0001), respectively for female subjects. Multivariable logistic analysis revealed that hyperuricemia was significantly associated with MetS cumulative incidence in male subjects (OR 1.5: 95% CI: 1.3-1.8, P<0.0001) and female (OR 2.0, 95% CI: 1.3-3.0, P<0.0001). In conclusion, hyperuricemia is a significant and independent predictor of MetS in Japanese male and female subjects. For both genders, MetS risk increases with increased serum uric acid levels.

Uric acid lowering to prevent kidney function loss in diabetes: the preventing early renal function loss (PERL) allopurinol study

Diabetic kidney disease causes significant morbidity and mortality among people with type 1 diabetes (T1D). Intensive glucose and blood pressure control have thus far failed to adequately curb this problem and therefore a major need for novel treatment approaches exists. Multiple observations link serum uric acid levels to kidney disease development and progression in diabetes and strongly argue that uric acid lowering should be tested as one such novel intervention. A pilot of such a trial, using allopurinol, is currently being conducted by the Preventing Early Renal Function Loss (PERL) Consortium. Although the PERL trial targets T1D individuals at highest risk of kidney function decline, the use of allopurinol as a renoprotective agent may also be relevant to a larger segment of the population with diabetes. As allopurinol is inexpensive and safe, it could be cost-effective even for relatively low-risk patients, pending the completion of appropriate trials at earlier stages.

The pathophysiology of hyperuricaemia and its possible relationship to cardiovascular disease, morbidity and mortality

Uric acid is the end product of purine metabolism in humans. High levels are causative in gout and urolithiasis. Hyperuricaemia has also been implicated in the pathophysiology of hypertension, chronic kidney disease (CKD), congestive heart failure (CHF), the metabolic syndrome, type 2 diabetes mellitus (T2DM), and atherosclerosis, with or without cardiovascular events. This article briefly reviews uric acid metabolism and summarizes the current literature on hyperuricaemia in cardiovascular disease and related co-morbidities, and emerging treatment options.

Relationship between serum uric acid levels and metabolic syndrome in Chinese postmenopausal women

OBJECTIVE

Serum uric acid levels have been reported to be associated with metabolic syndrome (MetS). However, few studies specifically examining the relationship between serum uric acid (SUA) levels and MetS in postmenopausal women have been reported in China. Thus, we conducted this study in order to assess the relationship between SUA levels and MetS in Chinese postmenopausal women.

METHODS

A cross-sectional study of 1022 Chinese postmenopausal women (aged 42-80 years) who participated in annual health check-ups was employed. MetS was defined by National Cholesterol Education Program/Adult Treatment Panel III criteria (NCEP-ATP III). Of all the participants, 385 women were diagnosed with MetS (MetS group) and the others were without MetS (non-MetS group). SUA quartiles were defined as follows: Q1, < 3.9 mg/dl; Q2, 3.9-4.5 mg/dl; Q3, 4.6-5.1 mg/dl; Q4, 5.2-6.0 mg/dl. The association between SUA quartiles and MetS was assessed using binary logistic regression.

RESULTS

The adjusted odds ratio (95% confidence interval) for the presence of metabolic syndrome in the highest SUA quartile vs. the lowest quartile was 3.768 (2.386-5.950) for all women (p < 0.01) after adjusting for age, body mass index, blood urea nitrogen, serum creatinine, total cholesterol, low density lipoprotein cholesterol and C-reactive protein. The presence of MetS significantly increased in the second, third and fourth quartiles of SUA. The prevalence of MetS increased gradually with an increasing serum uric acid quartile (p for trend < 0.001).

CONCLUSION

Higher SUA levels are positively and independently associated with the presence of MetS in Chinese postmenopausal women.

Persistent organic pollutants and hyperuricemia in the U.S. general population

BACKGROUND

Background exposure to persistent organic pollutants (POPs) has emerged as a new risk factor for metabolic syndrome (MetS), while hyperuricemia is associated with MetS through unclear mechanisms.

OBJECTIVE

We examined cross-sectional data for consistency with the hypothesis that POPs are a common underlying risk factor of both MetS and hyperuricemia.

METHODS

We evaluated associations of POPs with hyperuricemia in subjects aged ≥20 years in the population-based National Health and Nutrition Examination Survey (NHANES) 2003-2004. Sample size was n = 1331 for organochlorine (OC) pesticides and n = 1299 for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs).

RESULTS

Among all subjects, the risk of hyperuricemia was higher for higher serum concentrations of OC pesticides, PCDDs, and dioxin-like PCBs. PCDFs and nondioxin-like PCBs did not show any clear trend. Adjusted odds ratios (ORs) for OC pesticides, PCDDs, and dioxin-like PCBs were 1.0, 2.4, 2.3, 3.0, and 2.5 (P trend = 0.05), 1.0, 1.6, 1.4, 2.1, and 2.5 (P trend = 0.01), and 1.0, 1.3, 1.4, 1.3, and 2.4 (P trend = 0.04). When we restricted the analyses to subjects without MetS, all these associations appeared to strengthen.

CONCLUSION

This study is consistent with our hypothesis that the risk of hyperuricemia relates to background exposure to a mixture of POPs even among persons without MetS. There should be further research about whether avoiding exposure to POPs and otherwise decreasing body burden of POPs would be helpful to prevent or manage hyperuricemia or gout.