Uric acid and cardiovascular risk

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Psoriasis and cardiovascular risk: strength in numbers, part II

The Psoralen plus Ultraviolet-A (PUVA) cohort study has been a tremendous success in determining how a novel treatment (i.e., PUVA) affects the long-term risk of keratinocyte carcinoma. The ability to follow patients from the initial multicenter clinical trial for more than three decades has been a remarkable achievement in dermatoepidemiology. In this issue, Stern and Huibregtse report results from the PUVA follow-up study and conclude that only patients with exceptionally severe psoriasis have an increased overall mortality risk and that there is no significant risk of cardiovascular mortality associated with psoriasis. The results are in contrast to a large and growing body of literature that suggests patients with more severe psoriasis have a clinically significant increased risk of mortality in general and cardiovascular disease in particular. In addition, the authors found no association between severe psoriasis and obesity or between obesity and cardiovascular mortality, despite extensive literature establishing these associations. Basic principles of epidemiological study design may explain these discrepancies. Ultimately, however, randomized clinical trials will be necessary to determine whether severe psoriasis is in fact a "visible killer," as four decades ago (after many years of controversy) hypertension was recognized to be a "silent killer."

Urate as a physiological substrate for myeloperoxidase: implications for hyperuricemia and inflammation

Urate and myeloperoxidase (MPO) are associated with adverse outcomes in cardiovascular disease. In this study, we assessed whether urate is a likely physiological substrate for MPO and if the products of their interaction have the potential to exacerbate inflammation. Urate was readily oxidized by MPO and hydrogen peroxide to 5-hydroxyisourate, which decayed to predominantly allantoin. The redox intermediates of MPO were reduced by urate with rate constants of 4.6 × 10(5) M(-1) s(-1) for compound I and 1.7 × 10(4) M(-1) s(-1) for compound II. Urate competed with chloride for oxidation by MPO and at hyperuricemic levels is expected to be a substantive substrate for the enzyme. Oxidation of urate promoted super-stoichiometric consumption of glutathione, which indicates that it is converted to a free radical intermediate. In combination with superoxide and hydrogen peroxide, MPO oxidized urate to a reactive hydroperoxide. This would form by addition of superoxide to the urate radical. Urate also enhanced MPO-dependent consumption of nitric oxide. In human plasma, stimulated neutrophils produced allantoin in a reaction dependent on the NADPH oxidase, MPO and superoxide. We propose that urate is a physiological substrate for MPO that is oxidized to the urate radical. The reactions of this radical with superoxide and nitric oxide provide a plausible link between urate and MPO in cardiovascular disease.

Hyperuricemia as a mediator of the proinflammatory endocrine imbalance in the adipose tissue in a murine model of the metabolic syndrome

OBJECTIVE

Hyperuricemia is strongly associated with obesity and metabolic syndrome and can predict visceral obesity and insulin resistance. Previously, we showed that soluble uric acid directly stimulated the redox-dependent proinflammatory signaling in adipocytes. In this study we demonstrate the role of hyperuricemia in the production of key adipokines.

RESEARCH DESIGN AND METHODS

We used mouse 3T3-L1 adipocytes, human primary adipocytes, and a mouse model of metabolic syndrome and hyperuricemia.

RESULTS

Uric acid induced in vitro an increase in the production (mRNA and secreted protein) of monocyte chemotactic protein-1 (MCP-1), an adipokine playing an essential role in inducing the proinflammatory state in adipocytes in obesity. In addition, uric acid caused a decrease in the production of adiponectin, an adipocyte-specific insulin sensitizer and anti-inflammatory agent. Uric acid-induced increase in MCP-1 production was blocked by scavenging superoxide or by inhibiting NADPH oxidase and by stimulating peroxisome-proliferator-activated receptor-γ with rosiglitazone. Downregulation of the adiponectin production was prevented by rosiglitazone but not by antioxidants. In obese mice with metabolic syndrome, we observed hyperuricemia. Lowering uric acid in these mice by inhibiting xanthine oxidoreductase with allopurinol could improve the proinflammatory endocrine imbalance in the adipose tissue by reducing production of MCP-1 and increasing production of adiponectin. In addition, lowering uric acid in obese mice decreased macrophage infiltration in the adipose tissue and reduced insulin resistance.

CONCLUSIONS

Hyperuricemia might be partially responsible for the proinflammatory endocrine imbalance in the adipose tissue, which is an underlying mechanism of the low-grade inflammation and insulin resistance in subjects with the metabolic syndrome.

First trimester uric acid and adverse pregnancy outcomes

BACKGROUND

The association of elevated serum uric acid with the development of hypertension is established outside of pregnancy. We investigated whether first trimester uric acid was associated with the development of the following: gestational hypertension or pre eclampsia, these outcomes stratified by presence of hyperuricemia at delivery since this denotes more severe disease, preterm birth, or small for gestational age (SGA).

METHODS

Uric acid was measured in 1,541 banked maternal plasma samples from a prior prospective cohort study that were collected at a mean gestational age of 9.0 (± 2.5) weeks. Polytomous regressions were performed and adjusted for parity and prepregnancy body mass index (BMI).

RESULTS

First trimester uric acid in the highest quartile (>3.56 mg/dl) compared to lowest three quartiles was associated with an increased risk of developing pre-eclampsia (adjusted odds ratio (OR) = 1.82; 95% confidence interval (CI), 1.03-3.21) but not gestational hypertension. In women with hypertensive disease complicated by hyperuricemia at delivery, high first trimester uric acid was associated with a 3.22-fold increased risk of hyperuricemic gestational hypertension (HU) and a 3.65-fold increased risk of hyperuricemic pre-eclampsia (HPU). High first trimester uric acid was not associated with gestational hypertension or pre-eclampsia without hyperuricemia (H or HP) at delivery, preterm birth, or SGA. In women who developed hypertensive disease, elevated uric acid at delivery was only partly explained by elevated uric acid in the first trimester (r(2) = 0.23).

CONCLUSIONS

First trimester elevated uric acid was associated with later pre-eclampsia and more strongly with pre-eclampsia and gestational hypertension with hyperuricemia.

Sugar-sweetened beverages and hypertension

Consumption of sugar-sweetened beverages has been associated with the development and maintenance of obesity, as well as the risk for multiple obesity-related comorbidities. Some experts have hypothesized that the effect is entirely associated with excess caloric intake, while others suggest that a component of sweeteners may have a physiologic impact on the development of hypertension, insulin resistance and nonalcoholic fatty liver disease. Chen et al. have presented the first, large-scale clinical trial, assessing the direct effect of modest changes in sweetened drink consumption on blood pressure in a racially diverse population. The study team utilized data from the PREMIER: Lifestyle Interventions for Blood Pressure Control trial, in which 810 adult subjects were randomized to three groups: advice only; comprehensive lifestyle modification aimed at weight loss, increased exercise and dietary sodium reduction; or comprehensive lifestyle modification with incorporation of the Dietary Approach to Stop Hypertension (DASH) diet. Sweetened drink intake was estimated from 24-h subject recall, assessed by unscheduled phone calls to subjects at baseline, 6 months and 18 months. Over the duration of the study, a reduction of one 12-oz serving of sugar-sweetened beverages per day was associated with an average of 1.8 mmHg reduction in systolic blood pressure and an average of 1.1 mmHg reduction in diastolic blood pressure.

Developing potent human uric acid transporter 1 (hURAT1) inhibitors

The kidneys are a vital organ in the human body. They serve several purposes including homeostatic functions such as regulating extracellular fluid volume and maintaining acid-base and electrolyte balance and are essential regarding the excretion of metabolic waste. Furthermore, the kidneys play an important role in uric acid secretion/reabsorption. Abnormalities associated with kidney transporters have been associated with various diseases, such as gout. The current study utilized Xenopus oocytes expressing human uric acid transporter 1 (hURAT1; SLC22A12) as an in vitro method to investigate novel compounds and their ability to inhibit (14)C-uric acid uptake via hURAT1. We have prepared and tested a series of 2-ethyl-benzofuran compounds and probed the hURAT1 in vitro inhibitor structure-activity relationship. As compared to dimethoxy analogues, monophenols formed on the C ring showed the best in vitro inhibitory potential. Compounds with submicromolar (i.e., IC(50) < 1000 nM) inhibitors were prepared by brominating the corresponding phenols to produce compounds with potent uricosuric activity.

Hyperuricemia in kidney transplant recipients with intact graft function

OBJECTIVES

The aim of this study was to investigate the prevalence of hyperuricemia and factors predicting its occurrence, and to establish the relationship over time between serial changes in estimated glomerular filtration rate (eGFR) and uric acid (UR) concentration in kidney transplant (KT) recipients with eGFR >60 mL/min/1.73 m(2).

METHODS

Adult patients who underwent KT at the Asan Medical Center between 1990 and 2008 and maintained eGFR >60 mL/min/1.73 m(2) were retrospectively assessed. Clinical and laboratory data were obtained from inpatient and outpatient charts and from the hospital electronic database.

RESULTS

Of 356 patients, 301 (84.55%) had normal UR levels and 55 (15.45%) had hyperuricemia. After multivariate adjustment, transplant duration, male gender, eGFR, diabetes mellitus (DM), and calcium level were associated with higher mean UR levels. Mean UR level increased significantly and mean eGFR decreased significantly during the first year after transplantation, but there were no significant differences over the next 4 years. Serial UR and eGFR levels changed almost simultaneously.

CONCLUSIONS

Transplantation duration, male gender, eGFR level, DM, and serum calcium level were risk factors for hyperuricemia in kidney recipients with intact graft function. Increased uric acid after KT did not significantly affect graft function.

A young man with oligoarthritis: what is his cardiovascular risk?

Gout is the commonest cause of inflammatory arthritis among young men. A case of acute gout in a 39-year-old man is described. As part of his assessment, his cardiovascular risk factors were evaluated. He was found to have elevated body mass index, central obesity, hypertension, a family history of cardiovascular disease, and hypercholesterolemia. This case highlights the association between gout, hyperuricaemia and elevated cardiovascular risk. In young male patients, acute presentation with gout in primary care may provide the first opportunity for assessment of cardiovascular risk factors and primary prevention of ischaemic heart disease.

The relationship between normal serum uric acid and nonalcoholic fatty liver disease

The objective of the present study was to determine the relationship between serum uric acid (SUA) level and the presence of nonalcoholic fatty liver disease (NAFLD). We analyzed data of 9,019 Koreans who visited a health check up center. The SUA levels of all of these subjects were within the normal range. The participants were divided into 4 groups according to the quartiles of the SUA levels for both sexes. Hepatic steatosis was diagnosed on the basis of ultrasonographic findings. Multivariate logistic regression modeling was performed across the SUA quartiles. The presence of NAFLD and metabolic abnormalities were found significantly in subjects with high-normal SUA levels. After adjustment for age, metabolic components, and the liver-function test, the adjusted odds ratio (OR, 95% CIs) for the presence of NAFLD in the subjects with the highest SUA level was 1.46 (1.17-1.82) for men and 2.13 (1.42-3.18) for women, as compared to the subjects with the lowest SUA level. Our results suggest that increased SUA concentrations, even within the normal range, are independently associated with the presence of NAFLD.

Effects of thyroid dysfunction on lipid profile

Thyroid dysfunction has a great impact on lipids as well as a number of other cardiovascular risk factors. Hypothyroidism is relatively common and is associated with an unfavorable effect on lipids. Substitution therapy is beneficial for patients with overt hypothyroidism, improving lipid profile. However, whether subclinical hypothyroidism should be treated or not is a matter of debate. On the other hand, hyperthyroidism can be associated with acquired hypocholesterolemia or unexplained improvement of lipid profile. Overall, thyroid dysfunction should be taken into account when evaluating and treating dyslipidemic patients.

Challenges of conducting a trial of uric-acid-lowering therapy in CKD

Observational studies have shown that asymptomatic hyperuricemia is associated with increased risks of hypertension, chronic kidney disease (CKD), end-stage renal disease, cardiovascular events, and mortality. Whether these factors represent cause, consequence or incidental associations, however, remains uncertain. Hyperuricemia could be a consequence of impaired kidney function, diuretic therapy or oxidative stress, such that elevated serum urate level represents a marker, rather than a cause, of CKD. On the other hand, small, short-term, single-center studies have shown improvements in blood-pressure control and slowing of CKD progression following serum urate lowering with allopurinol. An adequately powered randomized controlled trial is required to determine whether uric-acid-lowering therapy slows the progression of CKD. This article discusses the rationale for and the feasibility of such a trial. International collaboration is required to plan and conduct a large-scale multicenter trial in order to better inform clinical practice and public health policy about the optimal management of asymptomatic hyperuricemia in patients with CKD.

A genome-wide association study of serum uric acid in African Americans

Background

Uric acid is the primary byproduct of purine metabolism. Hyperuricemia is associated with body mass index (BMI), sex, and multiple complex diseases including gout, hypertension (HTN), renal disease, and type 2 diabetes (T2D). Multiple genome-wide association studies (GWAS) in individuals of European ancestry (EA) have reported associations between serum uric acid levels (SUAL) and specific genomic loci. The purposes of this study were: 1) to replicate major signals reported in EA populations; and 2) to use the weak LD pattern in African ancestry population to better localize (fine-map) reported loci and 3) to explore the identification of novel findings cognizant of the moderate sample size.

Methods

African American (AA) participants (n = 1,017) from the Howard University Family Study were included in this study. Genotyping was performed using the Affymetrix^® Genome-wide Human SNP Array 6.0. Imputation was performed using MACH and the HapMap reference panels for CEU and YRI. A total of 2,400,542 single nucleotide polymorphisms (SNPs) were assessed for association with serum uric acid under the additive genetic model with adjustment for age, sex, BMI, glomerular filtration rate, HTN, T2D, and the top two principal components identified in the assessment of admixture and population stratification.

Results

Four variants in the gene SLC2A9 achieved genome-wide significance for association with SUAL (p-values ranging from 8.88 × 10^-9 to 1.38 × 10^-9). Fine-mapping of the SLC2A9 signals identified a 263 kb interval of linkage disequilibrium in the HapMap CEU sample. This interval was reduced to 37 kb in our AA and the HapMap YRI samples.

Conclusions

The most strongly associated locus for SUAL in EA populations was also the most strongly associated locus in this AA sample. This finding provides evidence for the role of SLC2A9 in uric acid metabolism across human populations. Additionally, our findings demonstrate the utility of following-up EA populations GWAS signals in African-ancestry populations with weaker linkage disequilibrium.

Hyperuricemia and associated factors: a cross-sectional study of Japanese-Brazilians

This cross-sectional study aimed to estimate the prevalence of hyperuricemia and associated risk factors among Japanese-Brazilians. We obtained data on demographic, health history, food intake, and laboratory variables. Chi-square and prevalence ratios were used as measures of association. 35.3% of the subjects presented hyperuricemia, which was more frequent in smokers, males, age > 55 years, with co-morbidities, individuals on uric acid-increasing medication, serum creatinine > 1.4mg/dL, high alcohol consumption, and low consumption of milk and dairy products. In the multivariate analysis, the associations remained significant with gender, overweight, central obesity, hypertriglyceridemia, and use of specific drugs. Among males, low intake of saturated fat was associated with hyperuricemia. Individuals with hypertension showed a negative association with dairy product consumption. The high hyperuricemia prevalence suggests that changes in nutritional profile and control of associated co-morbidities could help minimize occurrence of this condition.

Uric acid as a predictor of all-cause mortality in heart failure: a meta-analysis

Serum uric acid (SUA) is a product of xanthine oxidase (XO). Apoptosis and tissue hypoxia lead to increased purine catabolism, which, in turn, increases XO activity and subsequently SUA levels. The purpose of this study was to perform a meta-analysis to evaluate the evidence supporting SUA as a predictor of all-cause mortality in patients with heart failure (HF) and to determine the SUA cut-off for the increase in risk. A search of the MEDLINE database (1966 to March 2009) supplemented by manual searches of bibliographies of key relevant articles was performed. The authors selected all cohort studies in which SUA was measured and mortality was reported in patients with HF. The pooled relative risk (RR) with the corresponding 95% confidence interval (CI) for all-cause mortality using the fixed-effects method was calculated. The effects of SUA on all-cause mortality at different SUA cut-offs using meta-regression was evaluated. The search strategy yielded 358 studies, of which only 6 met our eligibility criteria. The studies, however, comprised 1456 evaluable patients with HF, with a median ejection fraction of 32% (range, 26%-40%). The RR of all-cause mortality was 2.13 (95% CI, 1.78-2.55) for SUA>6.5 mg/dL compared with <6.5 mg/dL SUA level. There was a linear association (P<.01) between SUA and mortality after 7 mg/dL. Uric acid is an important prognostic marker for all-cause mortality in HF. SUA levels >7 mg/dL are associated with higher all-cause mortality.

The NLRP3 inflammasome instigates obesity-induced inflammation and insulin resistance

Emergence of chronic ‘sterile’ inflammation during obesity in absence of overt infection or autoimmune process is a puzzling phenomenon. The Nod Like Receptor (NLR) family of innate immune cell sensors like the Nlrp3 inflammasome are implicated in recognizing certain non-microbial origin ‘danger–signals’ leading to caspase-1 activation and subsequent IL-1β and IL-18 secretion. We show that reduction in adipose tissue expression of Nlrp3 is coupled with decreased inflammation and improved insulin–sensitivity in obese type-2 diabetic patients. The Nlrp3 inflammasome senses the lipotoxicity–associated ceramide to induce caspase-1 cleavage in macrophages and adipose tissue. Ablation of Nlrp3 prevented the obesity–induced inflammasome activation in fat depots and liver together with enhanced insulin–signalling. Furthermore, elimination of Nlrp3 in obesity reduced IL-18 and adipose tissue IFNγ along with an increase in naïve and reduction in effector adipose tissue T cells. Collectively, these data establish that Nlrp3 inflammasome senses obesity–associated ‘danger–signals’ and contributes to obesity–induced inflammation and insulin–resistance.

Association of serum uric acid level with aortic stiffness and arterial wave reflections in newly diagnosed, never-treated hypertension

BACKGROUND

Serum uric acid (UA) plays a key role in the development and progression of hypertension. We investigated the association of UA levels and indices of arterial function in a cohort of newly diagnosed, never-treated hypertensive subjects.

METHODS

One thousand two hundred and twenty-five patients with a new diagnosis of mild to moderate arterial hypertension for which they had never received treatment were enrolled in the study (mean age 52.9 years, 728 men). Serum UA, carotid-femoral pulse-wave velocity (cfPWV), an index of aortic stiffness and augmentation index (AIx), a composite marker of wave reflections and arterial stiffness were measured.

RESULTS

In univariable analysis, UA levels correlated with cfPWV (r = 0.23, P < 0.001) and AIx (r = -0.24, P < 0.001). In multiple linear regression analysis, an independent positive association of cfPWV with UA levels was observed after adjusting for confounders (standardized regression coefficient β = 0.169, P < 0.001, adjusted R² = 0.402), indicating an increase in aortic stiffness with higher values of UA. In contrast, an independent negative association of AIx with UA levels was observed after adjusting for confounders (standardized regression coefficient β = -0.064, P = 0.011, adjusted R² = 0.557), indicating a decrease in wave reflections with higher values of UA. In gender-specific analyses, UA positively correlated with cfPWV in both genders, whereas a negative correlation with AIx existed only in females.

CONCLUSIONS

Serum UA levels are independently associated with aortic stiffening and wave reflections in never-treated hypertensives. Future studies are warranted in order to explore its exact role on arterial function in the hypertensive setting.

Metabolic syndrome frequency in inflammatory bowel diseases

BACKGROUND/AIM

Metabolic syndrome (MetS) is a clinical condition characterized by central obesity, elevated triglycerides, low-high density lipoproteins, impaired fasting glucose, and hypertension. There is insufficient data on the prevalence of MetS in patients with inflammatory bowel disease (IBD). This study sought to determine the prevalence of MetS in a Turkish cohort of patients with IBD and the association between insulin resistance (IR) and the MetS parameters, in this population.

PATIENTS AND METHODS

A total of 177 patients over 18 years of age (62 with Crohn's disease (CD) and 115 with ulcerative colitis (UC)) were enrolled in the study. The presence of at least three criteria of the International Diabetes Federation (IDF) was accepted for the diagnosis of MetS. The Homeostasis Model Assessment (HOMA) was used to determine IR. HOMA values < 1 were considered normal and values > 2.5 indicated a high probability of IR.

RESULTS

MetS frequency was higher in patients n=34 (29.5%) with UC than in patients n=11 (17.7%) with CD (P < 0.01). MetS was detected in 12 of the 117 patients (10.3%) with IBD, under 45 years of age, and in 33 of 60 patients (55%) over 45 years of age. HOMA value in n=31 patients (27%) with UC was > 2.5. Body mass index, insulin (P < 0.001), waist circumference, fasting plasma glucose, leukocyte count (P < 0.01), triglycerides, C-reactive protein, and uric acid values (P < 0.05) were significantly higher in UC patients with IR than those without IR.

CONCLUSION

Frequent occurrence of MS with increasing age in IBD, particularly in UC, showed the importance of early diagnosis and treatment of cardiovascular disease risk factors in the long-term follow-up of these diseases.

Improvement of hypertension after parathyroidectomy of patients suffering from primary hyperparathyroidism

Background. Primary hyperparathyroidism (PHPT) is one of the most common endocrine conditions and is accompanied by hypertension and increased cardiovascular mortality. The purpose of this study was to evaluate the effect of parathyroidectomy on systolic and diastolic blood pressure (BP) in hypertensive patients with PHPT and whether hypertension occurs more frequently in PHPT than in control group. Methods. A total of 1020 patients with proved PHPT who underwent surgery were compared with with 1020 age, sex, BMI, and smoking status matched controls. We evaluated changes in serum calcium, parathyroid hormone (PTH), uric acid, and BP before and 6 months after surgery. Results. Parathyroidectomy corrected PHPT and resulted in a substantial fall in both mean systolic (150 ± 3.8 to 138 ± 3.6 mmHg) and mean diastolic pressures (97 ± 3 to 88 ± 2.8 mmHg) of the hypertensive subjects; P < .01. In these patients, PTH, calcium, and uric acid normalized. 726 patients from 1020 with PHPT (69.8%) were found to be hypertensive whilst only 489 (47.8%) from 1020 of our control group. Conclusion. Parathyroidectomy in hypertensive patients reduces systolic and diastolic BP. PHPT is accompanied by a variety of metabolic complications, which are a risk factor for hypertension, and parathyroidectomy can improve these metabolic complications.

Increased prevalence of metabolic syndrome associated with rheumatoid arthritis in patients without clinical cardiovascular disease

OBJECTIVE

to examine whether patients with rheumatoid arthritis (RA) with no overt cardiovascular disease (CVD) have a higher prevalence of metabolic syndrome (MetS) than subjects without RA or CVD. We also examined whether RA disease characteristics are associated with the presence of MetS in RA patients without CVD.

METHODS

subjects from a population-based cohort of patients who fulfilled 1987 American College of Rheumatology criteria for RA between January 1, 1980, and December 31, 2007, were compared to non-RA subjects from the same population. All subjects with any history of CVD were excluded. Waist circumference, body mass index (BMI), and blood pressure were measured during the study visit. Data on CVD, lipids, and glucose measures were ascertained from medical records. MetS was defined using NCEP/ATP III criteria. Differences between the 2 cohorts were examined using logistic regression models adjusted for age and sex.

RESULTS

the study included 232 RA subjects without CVD and 1241 non-RA subjects without CVD. RA patients were significantly more likely to have increased waist circumference and elevated blood pressure than non-RA subjects, even though BMI was similar in both groups. Significantly more RA patients were classified as having MetS. In RA patients, MetS was associated with Health Assessment Questionnaire Disability Index, large-joint swelling, and uric acid levels, but not with C-reactive protein or RA therapies.

CONCLUSION

among subjects with no history of CVD, patients with RA are more likely to have MetS than non-RA subjects. MetS in patients with RA was associated with some measures of disease activity.

Uric acid levels and atrial fibrillation in hypertensive patients

OBJECTIVE

Uric acid (UA) is a cardiovascular risk marker associated with oxidative stress and inflammation. Recently, atrial fibrillation (AF) has been associated with inflammation and oxidative stress. The objective of this observational study was to investigate the association between UA levels and AF in hypertensive patients.

METHODS

Consecutive patients with hypertension were screened. We excluded subjects with coronary artery disease, congestive heart failure, diabetes, valvular heart disease, congenital heart disease, cardiomyopathy, renal failure, inflammatory conditions, thyroid dysfunction, respiratory diseases, and those who were taking drugs that affect UA metabolism (apart from diuretics). The final study population consisted of 451 patients. Fifty of them (11%) had AF (paroxysmal: 38; persistent: 8; permanent: 4). Demographic, clinical, laboratory, and echocardiographic characteristics were carefully recorded.

RESULTS

After univariate analysis, age, duration of hypertension, serum creatinine, serum UA, left atrial diameter (LAD), interventricular septum thickness, and left ventricular posterior wall thickness were significantly increased in patients with AF compared with non-AF patients, while the estimated glomerular filtration (eGFR) level was much lower in patients with AF than in those without AF. After multivariate logistic regression analysis, the independent predictors of AF were UA (OR: 1.008; 95% CI: 1.003-1.013, p=0.002) and LAD (OR: 1.160; 95% CI: 1.068-1.260; p<0.001).

CONCLUSION

We demonstrated an independent association between increased serum UA levels and AF in hypertensive patients. Undoubtedly, larger studies in different populations should further examine this potential association as well as the underlying pathophysiological mechanisms.

Influence of physical activity intensity and aerobic fitness on the anthropometric index and serum uric acid concentration in people with obesity

BACKGROUND AND OBJECTIVE

Physical activity (PA) is considered an important approach to prevent and treat obesity and hyperuricemia. The purpose of the present study was to examine the influence of PA intensity and aerobic fitness on anthropometric indices and serum uric acid in obese individuals.

METHODS

PA was examined using a single-axial accelerometer and aerobic fitness was assessed by electric cycle ergometry in obese middle-aged men (n=71, 47.2 ± 4.4 years). PA was defined as light (<3 metabolic equivalents [METs]), moderate (3.0-6.0 METs) or vigorous (>6.0 METs) intensity from the corresponding METs multiplied by time spent at the corresponding intensity levels. Serum uric acid was measured by the uricase peroxidase method.

RESULTS

The association between aerobic fitness index (lactate threshold) and serum uric acid did not reach statistical significance after adjustment for potential confounding factors (age, body mass index [BMI], and alcohol consumption) (β=-0.110, p=0.138). Light intensity PA was inversely associated with BMI and waist circumference, even after adjustment for age and alcohol consumption (BMI: β=-0.543, p=0.023; waist circumference: β=-1.333, p=0.016). Moderate intensity PA, but not light or vigorous intensity PA, was inversely correlated with the uric acid level and this remained significant after adjustment for age, BMI, and alcohol consumption (β=-0.222, p=0.036).

CONCLUSION

Our results suggest that light intensity PA may have an important role in weight control while moderate intensity PA may be associated with the lower uric acid concentrations in obese individuals.

The diabetic CKD patient--a major cardiovascular challenge

The diabetic patient with chronic kidney disease (CKD) is at very high risk of cardiovascular disease (CVD). Primary and secondary CVD prevention is of major importance and should be targeted at both traditional cardiovascular risk factors and risk factors specific for patients with CKD, such as albuminuria, anaemia and CKD--mineral and bone disorder. However, treatment goals have largely been derived from clinical trials including patients with no or only mild CKD and may not be generalizable to patients with advanced renal disease. Moreover, in patients on renal replacement therapy, the association between traditional CVD risk factors and the incidence of CVD may be reversed, and pharmaceutical interventions that are beneficial in the general population may be ineffective or even harmful in this high-risk population. Those involved in the delivery of care to patients with diabetes and CKD need to be aware of these issues and should adopt an individualised approach to treatment.

Effect of the metabolic syndrome and hyperuricemia on outcome in patients with coronary artery disease (from the Bezafibrate Infarction Prevention Study)

Hyperuricemia appears to be related to metabolic syndrome (MS), but its impact on cardiovascular risk in patients with MS is unclear. We evaluated the impact of hyperuricemia on cardiovascular risk in patients with MS. Of 2,963 patients with coronary artery disease enrolled in the Bezafibrate Infarction Prevention study, 1,410 had MS, as established by the presence of ≥3 of the following 5 criteria: serum fasting glucose >110 mg/dl, triglycerides >150 mg/dl, high-density lipoprotein cholesterol <40 mg/dl in men and <50 mg/dl in women, systolic and diastolic blood pressures >130 and 80 mm Hg, respectively, and body mass index >28 kg/m². The remaining 1,553 patients had no MS. Primary end points were defined as occurrence of acute myocardial infarction or sudden cardiac death. Hyperuricemia was defined as serum uric acid levels >7.0 mg/dl in men and >6.0 mg/dl in women, respectively. Higher rate of primary end point was noted in hyperuricemic patients (n = 284) versus normouricemic patients (n = 1,126) with MS (20.1% and 15.3%, respectively, p = 0.05). After adjustment for age, gender, smoking, diabetes, previous myocardial infarction, hypertension, New York Heart Association classes II to IV, estimated glomerular filtration rate, body mass index, total cholesterol, triglycerides, diuretics, antiplatelets, angiotensin-converting enzyme inhibitors, β blockers, and bezafibrate treatment, hyperuricemic patients with MS demonstrated significantly higher risk for the primary end point compared to normouricemic patients with MS (hazard ratio 1.45, 95% confidence interval 1.00 to 2.17, p = 0.05). In conclusion, hyperuricemia is associated with increased risk of myocardial infarction and sudden cardiac death in patients with MS.

Allopurinol to Febuxostat: How far have we come?

For decades allopurinol has been used as a xanthine oxidase inhibitor for treatment of hyperuricemia and gout. Although effective in many patients, some experience sensitivity to the drug. In some cases, this sensitivity may lead to allopurinol hypersensitivity disorder, which if untreated can be fatal. Recently the Food and Drug Administration has approved the use of febuxostat as an alternative therapy for hyperuricemia and gout. Febuxostat is a new xanthine oxidase inhibitor, but is not purine based and therefore decreases adverse reactions due to patient sensitivity. This review is a comprehensive look at the background of hyperuricemia and gout treatment with allopurinol compared to recent clinical studies with febuxostat. Each clinical study is evaluated and summarized, identifying the advances in treatment that have been made as well as the concerns that still exist with either treatment.

Multiple genetic loci influence serum urate levels and their relationship with gout and cardiovascular disease risk factors

BACKGROUND

Elevated serum urate levels can lead to gout and are associated with cardiovascular risk factors. We performed a genome-wide association study to search for genetic susceptibility loci for serum urate and gout and investigated the causal nature of the associations of serum urate with gout and selected cardiovascular risk factors and coronary heart disease (CHD).

METHODS AND RESULTS

Meta-analyses of genome-wide association studies (GWAS) were performed in 5 population-based cohorts of the Cohorts for Heart and Aging Research in Genome Epidemiology consortium for serum urate and gout in 28 283 white participants. The effect of the most significant single-nucleotide polymorphism at all genome-wide significant loci on serum urate was added to create a genetic urate score. Findings were replicated in the Women's Genome Health Study (n=22 054). Single-nucleotide polymorphisms at 8 genetic loci achieved genome-wide significance with serum urate levels (P=4×10(-8) to 2×10(-242) in SLC22A11, GCKR, R3HDM2-INHBC region, RREB1, PDZK1, SLC2A9, ABCG2, and SLC17A1). Only 2 loci (SLC2A9, ABCG2) showed genome-wide significant association with gout. The genetic urate score was strongly associated with serum urate and gout (odds ratio, 12.4 per 100 μmol/L; P=3×10(-39)) but not with blood pressure, glucose, estimated glomerular filtration rate, chronic kidney disease, or CHD. The lack of association between the genetic score and the latter phenotypes also was observed in the Women's Genome Health Study.

CONCLUSIONS

The genetic urate score analysis suggested a causal relationship between serum urate and gout but did not provide evidence for one between serum urate and cardiovascular risk factors and CHD.

Association of renal manifestations with serum uric acid in Korean adults with normal uric acid levels

Several studies have reported that hyperuricemia is associated with the development of hypertension and cardiovascular disease. Increasing evidences also suggest that hyperuricemia may have a pathogenic role in the progression of renal disease. Paradoxically, uric acid is also widely accepted to have antioxidant activity in experimental studies. We aimed to investigate the association between glomerular filtration rate (GFR) and uric acid in healthy individuals with a normal serum level of uric acid. We examined renal function determined by GFR and uric acid in 3,376 subjects (1,896 men; 1,480 women; aged 20-80 yr) who underwent medical examinations at Gangnam Severance Hospital from November 2006 to June 2007. Determinants for renal function and uric acid levels were also investigated. In both men and women, GFR was negatively correlated with systolic and diastolic blood pressures, fasting plasma glucose, total cholesterol, uric acid, log transformed C reactive protein, and log transformed triglycerides. In multivariate regression analysis, total uric acid was found to be an independent factor associated with estimated GFR in both men and women. This result suggests that uric acid appears to contribute to renal impairment in subjects with normal serum level of uric acid.

New and improved strategies for the treatment of gout

The Western world appears to be in the midst of the third great gout epidemic of all time. In this century, gout is increasing in prevalence despite an increased understanding of its risk factors and pathophysiology, and the availability of reasonably effective treatment. The main cultural factors responsible for this appear to be diet, obesity, ethanol use and medications. Excess fructose consumption is a newly recognized modifiable risk factor. The debate has been renewed concerning hyperuricemia as an independent risk factor for renal insufficiency and cardiovascular disease. Prevention is still rooted in lifestyle choices. Existing treatments have proven to be unsatisfactory in many patients with comorbidities. New treatments are available today and on the horizon for tomorrow, which offer a better quality of life for gout sufferers. These include febuxostat, a nonpurine inhibitor of xanthine oxidase with a potentially better combination of efficacy and safety than allopurinol, and investigational inhibitors of URAT-1, an anion exchanger in the proximal tubule that is critical for uric acid homeostasis. New abortive treatments include interleukin-1 antagonists that can cut short the acute attack in 1 to 2 days in persons who cannot take nonsteroidal anti-inflammatory drugs, colchicine or corticosteroids. Lastly, newer formulations of uricase have the ability to dissolve destructive tophi over weeks or months in patients who cannot use currently available hypouricemic agents. Diagnostically, ultrasound and magnetic resonance imaging offer advanced ways to diagnose gout noninvasively, and just as importantly, a way to follow the progress of tophus dissolution. The close association of hyperuricemia with metabolic syndrome, hypertension and renal insufficiency ensures that nephrologists will see increasing numbers of gout-afflicted patients.