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

Comparison of switch to the highest dose of rosuvastatin vs. add-on nicotinic acid vs. add-on fenofibrate for mixed dyslipidaemia

BACKGROUND

Use of a statin at a standard dose may be insufficient for the treatment of mixed dyslipidaemia. Whether switch to the highest dose of rosuvastatin (40 mg) or add-on nicotinic acid (NA) or fenofibrate is more efficacious remains unknown.

PATIENTS AND METHODS

This was a prospective, randomised, open-label, blinded end-point (PROBE) study. We recruited 100 patients with mixed dyslipidaemia who were treated with a statin at a standard dose but had not achieved lipid targets. Patients were randomised to switch to the highest approved dose of rosuvastatin (40 mg), add-on extended release nicotinic acid (ER-NA)/l-aropiprant (LRPT) or to add-on micronised fenofibrate for 3 months. The primary end-point was the change in non-high-density lipoprotein cholesterol (non-HDL-C) levels.

RESULTS

Ninety patients completed the study. Non-HDL-C decreased in all groups (by 23, 24 and 7% in the rosuvastatin, ER-NA/LRPT and fenofibrate group, respectively, p < 0.01 for all compared with baseline and p < 0.01 for all compared with fenofibrate group). Low-density lipoprotein cholesterol (LDL-C) decreased by 23 and 19% in the rosuvastatin and ER-NA/LRPT group, respectively (p < 0.01 compared with baseline), but not in the add-on fenofibrate group. Add-on ER-NA/LRPT was associated with the greatest HDL-C increase, while add-on ER-NA/LRPT and add-on fenofibrate were associated with the greatest triglyceride decrease. Twenty-four per cent of patients initially randomised to add-on ER-NA/LRPT dropped out because of side effects.

CONCLUSIONS

In conclusion, switch to the highest dose of rosuvastatin and add-on ER-NA/LRPT may be better options compared with add-on fenofibrate for the management of patients with mixed dyslipidaemia not on treatment goals with a statin at a standard dose.

12 weeks' aerobic and resistance training without dietary intervention did not influence oxidative stress but aerobic training decreased atherogenic index in middle-aged men with impaired glucose regulation

Our aim was to determine whether 12 weeks' aerobic Nordic walking (NW) or resistance exercise training (RT) without diet-induced weight loss could decrease oxidative stress and atherogenic index of plasma (AIP), prevalence of metabolic syndrome (MetS) and MetS score in middle-aged men with impaired glucose regulation (IGR) (n=144. 54.5 ± 6.5 years). In addition, we compared effects of intervention between overweight and obese subgroups. Prevalence of MetS and AIP index decreased only in NW group and MetS score in both NW and RT groups but not in control group. The changes in AIP index correlated inversely with changes in plasma antioxidant capacity. The change in AIP index remained a significant independent predictor of the changes in MetS score after the model was adjusted for age, BMI and volume of exercise (MET h/week) in NW group. There were no changes in the other measured markers of oxidative stress and related cytokines (e.g. osteopontin and osteoprotegerin) in any of the groups. Nordic walking decreased prevalence of MetS and MetS score. Improved lipid profile remained a predictor of decreased MetS score only in NW group and it seems that Nordic walking has more beneficial effects on cardiovascular disease risks than RT training.

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

OBJECTIVE

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

MATERIALS/METHODS

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

RESULTS

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

CONCLUSIONS

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

Genome-wide association analyses identify 18 new loci associated with serum urate concentrations

Elevated serum urate concentrations can cause gout, a prevalent and painful inflammatory arthritis. By combining data from >140,000 individuals of European ancestry within the Global Urate Genetics Consortium (GUGC), we identified and replicated 28 genome-wide significant loci in association with serum urate concentrations (18 new regions in or near TRIM46, INHBB, SFMBT1, TMEM171, VEGFA, BAZ1B, PRKAG2, STC1, HNF4G, A1CF, ATXN2, UBE2Q2, IGF1R, NFAT5, MAF, HLF, ACVR1B-ACVRL1 and B3GNT4). Associations for many of the loci were of similar magnitude in individuals of non-European ancestry. We further characterized these loci for associations with gout, transcript expression and the fractional excretion of urate. Network analyses implicate the inhibins-activins signaling pathways and glucose metabolism in systemic urate control. New candidate genes for serum urate concentration highlight the importance of metabolic control of urate production and excretion, which may have implications for the treatment and prevention of gout.

Dietary, anthropometric, and biochemical determinants of uric acid in free-living adults

BACKGROUND

High plasma uric acid (UA) is a prerequisite for gout and is also associated with the metabolic syndrome and its components and consequently risk factors for cardiovascular diseases. Hence, the management of UA serum concentrations would be essential for the treatment and/or prevention of human diseases and, to that end, it is necessary to know what the main factors that control the uricemia increase. The aim of this study was to evaluate the main factors associated with higher uricemia values analyzing diet, body composition and biochemical markers.

METHODS

415 both gender individuals aged 21 to 82 years who participated in a lifestyle modification project were studied. Anthropometric evaluation consisted of weight and height measurements with later BMI estimation. Waist circumference was also measured. The muscle mass (Muscle Mass Index - MMI) and fat percentage were measured by bioimpedance. Dietary intake was estimated by 24-hour recalls with later quantification of the servings on the Brazilian food pyramid and the Healthy Eating Index. Uric acid, glucose, triglycerides (TG), total cholesterol, urea, creatinine, gamma-GT, albumin and calcium and HDL-c were quantified in serum by the dry-chemistry method. LDL-c was estimated by the Friedewald equation and ultrasensitive C-reactive protein (CRP) by the immunochemiluminiscence method. Statistical analysis was performed by the SAS software package, version 9.1. Linear regression (odds ratio) was performed with a 95% confidence interval (CI) in order to observe the odds ratio for presenting UA above the last quartile (♂UA > 6.5 mg/dL and ♀ UA > 5 mg/dL). The level of significance adopted was lower than 5%.

RESULTS

Individuals with BMI ≥ 25 kg/m2 OR = 2.28(1.13-4.6) and lower MMI OR = 13.4 (5.21-34.56) showed greater chances of high UA levels even after all adjustments (gender, age, CRP, gamma-gt, LDL, creatinine, urea, albumin, HDL-c, TG, arterial hypertension and glucose). As regards biochemical markers, higher triglycerides OR = 2.76 (1.55-4.90), US-CRP OR = 2.77 (1.07-7.21) and urea OR = 2.53 (1.19-5.41) were associated with greater chances of high UA (adjusted for gender, age, BMI, waist circumference, MMI, glomerular filtration rate, and MS). No association was found between diet and UA.

CONCLUSIONS

The main factors associated with UA increase were altered BMI (overweight and obesity), muscle hypotrophy (MMI), higher levels of urea, triglycerides, and CRP. No dietary components were found among uricemia predictors.

Plasma uric acid is associated with increased risk of type 2 diabetes independent of diet and metabolic risk factors

Current evidence suggests a direct association of uric acid with diabetes risk, but it is still unclear whether this is independent of risk factors such as obesity and diet. We aimed to investigate whether plasma uric acid concentrations are independently associated with incident type 2 diabetes and to investigate the role of a uric acid-related dietary pattern in this association. We used a case-cohort nested in the European Prospective Investigation into Cancer and Nutrition-Netherlands study. The study included 2318 subcohort members and 845 incident diabetes cases, with a mean follow-up of 10 y. At baseline, blood samples were taken and diet was assessed using a validated FFQ. A uric acid-related dietary pattern was derived with reduced rank regression. Diabetes was mainly self-reported and verified against general practitioner records. Plasma uric acid was (mean ± SD) 231 ± 54.6 μmol/L in the subcohort. After adjustment for established diabetes risk factors such as age, the HR (highest vs. lowest quartile of uric acid) for diabetes was 4.36 (95% CI: 3.22, 5.90). Further adjustment for adiposity attenuated the HR to 1.86 (95% CI: 1.32, 2.62). Additional adjustment for hypertension and biochemical markers, such as TG, slightly attenuated the association [HR = 1.43 (95% CI: 0.97, 2.10)]. A uric acid-related dietary pattern did not confound the association. In conclusion, this study supports that high uric acid concentrations are associated with increased diabetes risk, although a large part of the association can be explained by the degree of adiposity.

Uric acid best predicts metabolically unhealthy obesity with increased cardiovascular risk in youth and adults

OBJECTIVE

The obesity prevalence is growing worldwide and largely responsible for cardiovascular disease, the most common cause of death in the western world. The rationale of this study was to distinguish metabolically healthy from unhealthy overweight/obese young and adult patients as compared to healthy normal weight age matched controls by an extensive anthropometric, laboratory, and sonographic vascular assessment.

DESIGN AND METHODS

Three hundred fifty five young [8 to < 18 years, 299 overweight/obese(ow/ob), 56 normal weight (nw)] and 354 adult [>18-60 years, 175 (ow/ob), 179 nw)] participants of the STYJOBS/EDECTA (STYrian Juvenile Obesity Study/Early DEteCTion of Atherosclerosis) cohort were analyzed. STYJOBS/EDECTA (NCT00482924) is a crossectional study to investigate metabolic/cardiovascular risk profiles in normal and ow/ob people free of disease except metabolic syndrome (MetS).

RESULTS

From 299 young ow/ob subjects (8-< 18 years), 108 (36%), and from 175 adult ow/ob subjects (>18-60 years), 79 (45%) had positive criteria for MetS. In both age groups, prevalence of MetS was greater among males. Overweight/obese subjects were divided into "healthy" (no MetS criterion except anthropometry fulfilled) and "unhealthy" (MetS positive). Although percentage body fat did not differ between "healthy" and "unhealthy" ow/ob, nuchal and visceral fat were significantly greater in the "unhealthy" group which had also significantly higher values of carotid intima media thickness (IMT). With MetS as the dependent variable, two logistic regressions including juveniles <18 years or adults >18 years were performed. The potential predictor variables selected with the exception of age and gender by t test comparisons included IMT, ultrasensitive c-reactive protein (US-CRP), IL-6, malondialdehyde (MDA), oxidized LDL, leptin, adiponectin, uric acid (UA), aldosterone, cortisol, transaminases, fibrinogen. In both groups, uric acid and in adults only, leptin and adiponectin, turned out as the best predictor.

CONCLUSION

Serum levels of UA are a significant predictor of unhealthy obesity in juveniles and adults.

Association between Uric Acid and Metabolic Syndrome in Qazvin Metabolic Diseases Study (QMDS), Iran

Background:

The prevalence of Metabolic Syndrome (MS) has been increasing worldwide. Although Uric Acid (UA) Levels are often increased in subjects with MS, it is still unclear whether uric acid plays a causal role for MS or is a marker. The purpose of this study was to examine the association between UA and the MS in Qazvin, Iran.

Methods:

529 men and 578 women aged 20 – 78 years attended in cross sectional study from September 2010 to April 2011 in Qazvin, Iran. The criteria proposed by new joint Interim societies (JIS) were applied for diagnosis of MS. Hyperuricemia was defined as UA ≥ 7 mg/dL in men and UA ≥ 6 mg/dL in women. Logistic regression analysis was performed to evaluate the relationship between UA quartiles and MS.

Results:

The prevalence of MS was found to be 39.3%. Prevalence of hyperuricemia was 8.4% in males and 4.1% in females (P=0.004). Mean UA level was higher in males than in females (P<0.001). UA levels increased significantly with an increasing number of MS components in both genders. Prevalence of MS increased across UA quartiles in females; however the increasing trend began from second quartile in males. Using the lowest quartile of UA level as a reference, there were no significant association between UA quartile groups and MS.

Conclusion:

This study showed that UA levels are not an appropriate predictor of MS in Iranian population. More longitudinal studies are necessary to confirm the role of UA in MS occurrence.

Serum uric acid and appropriate cutoff value for prediction of metabolic syndrome among Chinese adults

The relation between serum uric acid and metabolic syndrome is observed not only with frank hyperuricemia but also with serum uric acid levels within the normal range. The current “normal” range set for hyperuricemia often fails to identify patients with potential metabolic disorders. We investigate the association between serum uric acid within the normal range and incident metabolic syndrome risk, and further to determine the optimal cut-off value of serum uric acid for the diagnosis or prediction of metabolic syndrome. A total of 7399 Chinese adults (2957 men and 4442 women; ≥20 years) free of metabolic syndrome were followed for 3 years. During the 3-year follow-up, 1190 normouricemic individuals developed metabolic syndrome (16.1%). After adjusting the associated variables, the top quartile of serum uric acid levels was associated with higher metabolic syndrome development compared with the bottom quartile in men (hazard ratio (HR), 1.29; p<0.05) and women (HR, 1.62; p<0.05). ROC curve analysis indicated that the optimal cut-off values for serum uric acid to identify metabolic syndrome were 6.3 mg/dl in men and 4.9 mg/dl in women. Our results suggested that high baseline serum uric acid levels within the normal range predict future development of metabolic syndrome after 3 y of follow-up.

Predictive value of serum uric acid levels for the diagnosis of metabolic syndrome in adolescents

OBJECTIVE

To evaluate the cause-effect relationships between serum levels of uric acid (UA) and metabolic syndrome (MetS) in an adolescent-male cohort that was followed for 2.7 years.

STUDY DESIGN

We enrolled male adolescents aged between 10 and 15 years at the baseline. A total of 613 subjects were divided into quartiles according to their UA levels, from UA-1 (the lowest) to UA-4 (the highest).

RESULTS

After the mean follow-up period of 2.7 ± 0.97 years, 19 (3.1%) subjects developed MetS. Waist circumference (WC), systolic blood pressure, high density lipoprotein cholesterol (HDL-C), and log triglyceride levels were significantly related to baseline UA levels. Compared with the UA-1 group, subjects in the UA-4 group had significantly higher OR for abnormal WC, blood pressure, and HDL-C at the end of follow-up and had a 6.39-fold higher OR (95% CI 1.41-29.08; P < .05) for having MetS. Subjects with UA >7.6 mg/dL had a 4.32 (95% CI 1.57-11.93) higher risk of developing MetS.

CONCLUSIONS

In this longitudinal study, we found that serum UA is correlated with future WC, systolic blood pressure, triglyceride, and HDL-C and is a risk factor for developing MetS. UA might be valuable in predicting adolescent MetS.

The uric acid metabolism pathway as a therapeutic target in hyperuricemia related to metabolic syndrome

INTRODUCTION

Uric acid (UA) increase is considered an important risk factor for the development of cardiovascular disease (CVD) favoring oxidative stress and endothelial dysfunction and is also involved in metabolic syndrome (MS) pathophysiology.

AREAS COVERED

Insulin has a physiological action on renal tubules, causing a reduction in UA clearance, what could explain the hyperuricemia found in MS. On the other hand, it was also hypothesized a causal role of UA in fructose-induced MS. Moreover, it has been suggested that higher UA levels predict the development of MS. MS subjects present a redox imbalance and UA participates in this process. UA can contribute to oxidative stress present in MS; however, it has also an important role in the antioxidant defense system. Although UA may have a protective effect due to its antioxidant properties, it is clear that the dominant effect of UA in MS is deleterious. All-cause mortality and CVD have been shown to be increased with higher UA levels.

EXPERT OPINION

It is extremely important to prescribe drugs which concomitantly decrease hyperuricemia and improve co-morbidities associated with hyperuricemia. Long-term studies to verify the consequences of decreasing UA concentration below current recommendations in asymptomatic patients are needed.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effects of aerobic exercise training on psychosocial status and serum uric Acid in men with essential hypertension: a randomized controlled trial

BACKGROUND

Chronic psychosocial stress and serum uric acid (SUA) level have been implicated in the etiology and cardiovascular events risk factors in hypertension. Studies have reported significant benefit of exercise in the overall management of hypertension. However, studies on the effect of exercise on psychosocial stress and SUA in the management of hypertension seem scanty.

AIM

The aim of this study was to determine the effect of continuous training program on SUA and psychosocial status of black African (Nigerian) population with hypertension.

SUBJECTS AND METHODS

Age-matched randomized controlled trial was used; subjects with diagnosis of hypertension attending the hypertensive clinic of Murtala Muhammed Specialist Hospital (MMSH), Kano, Nigeria form the population for the study. Two hundred and seventeen subjects with mild to moderate (systolic blood pressure (SBP) between 140 and180 and diastolic blood pressure (DBP) between 90 and 109 mmHg) essential hypertension were grouped into continuous (112) and control groups (105). The continuous group involved in an 8 weeks continuous training (60%-79% HR max) of between 45 and 60 min, 3 times per week, while the controls group remain sedentary. SBP, DBP, SUA, VO(2) max and psychosocial status were assessed. Student t-test and Pearson correlation test were used in data analysis.

RESULTS

The study revealed significant beneficial effect of continuous training programs on VO(2) max, SBP, DBP, SUA, and psychosocial status (P < 0.05). Psychosocial status and SUA was significantly and positively and negatively correlated respectively with VO(2) max at P < 0.01.

CONCLUSIONS

This study concludes and supports the recommendations of moderate intensity (continuous) training program in blood pressure reduction, SUA and psychosocial stress management in hypertension.

Urate transporter gene SLC22A12 polymorphisms associated with obesity and metabolic syndrome in Caucasians with hypertension

BACKGROUND/AIMS

Hyperuricemia is associated with obesity and the metabolic syndrome. URAT1 is a urate transporter, and we tested the association of URAT1 transporter gene (SLC22A12) polymorphisms with obesity and the metabolic syndrome in hypertensive subjects.

METHODS

Patients with essential hypertension (n = 414) from a randomized controlled study were genotyped for SLC22A12 SNPs rs11602903, rs505802 and rs11231825.

RESULTS

In Caucasians, SLC22A12 SNPs were associated with the body mass index (BMI). rs11602903 was associated with BMI (p < 0.0001), waist circumference (p = 0.003), HDL cholesterol (p = 0.018) and the metabolic syndrome (p = 0.033), and accounted for 7% of the variation of BMI in Caucasians. In African Americans, SLC22A12 SNP rs11602903 was not associated with BMI, waist circumference, HDL cholesterol or triglycerides.

CONCLUSION

The URAT1 gene SLC22A12 polymorphism may play a role in obesity and the metabolic syndrome in Caucasian hypertensive subjects.

A longitudinal cohort based association study between uric acid level and metabolic syndrome in Chinese Han urban male population

BACKGROUND

It has been recently demonstrated that serum uric acid (UA) is associated with metabolic syndrome (MetS) or its related clinical indications based on cross-sectional or prospective cohort studies. Nonetheless, due to the fact that UA level constantly fluctuates from time to time even for the person, using a single measure of UA level at baseline of those studies may not be sufficient for estimating the UA-Mets association.

METHODS

To further estimate this time-dependent association, we fitted a generalized estimating equation (GEE) regression model with data from a large-scale 6-year longitudinal study, which included 2222 participants aged > =25 years with an average of 3.5 repeated measures of UA per person in the Health Management Center of Shandong Provincial Hospital, Shandong, China.

RESULTS

After adjusting for other potential confounding factors (i.e., total cholesterol, low-density lipoprotein), it was verified that time-dependent UA level was an independent risk factor for MetS (OR = 1.6920, p < 0.0001). It was found that UA level was positively associated with obesity, hypertension, and dyslipidemia, but was inversely associated with hyperglycemia.

CONCLUSIONS

Serum UA level may serve as an important risk factor of MetS. Additionally, our study suggested that UA level be an independent risk factor to obesity, hypertension and dyslipidemia, but a protective factor to hyperglycemia. These findings are concordant with results from other studies on Asian populations, and jointly provide a basis to further develop a risk assessment model for predicting MetS using UA levels and other factors in China.

Purine-rich foods, protein intake, and the prevalence of hyperuricemia: the Shanghai Men's Health Study

BACKGROUND AND AIMS

Diet may play an important role in the development of hyperuricemia and gout. However, the association between dietary factors and hyperuricemia remains unclear, and few studies have investigated direct links between food intake and hyperuricemia. The aim of this study was to investigate associations between high purine-content foods and protein intake with the prevalence of hyperuricemia by using data from a cross-sectional study of 3978 men aged 40-74 yrs living in Shanghai, China.

METHODS AND RESULTS

Hyperuricemia was defined as blood uric acid level >7.0 mg/dl. One quarter of this population had hyperuricemia. Dietary information was collected by using a food frequency questionnaire. We collected information on anthropometric measurements and lifestyle factors and other potential confounding factors and disease history via interviews. Total protein consumption was not associated with hyperuricemia. We found a positive association between protein from animal sources and prevalence of hyperuricemia and an inverse association between protein from plant sources and hyperuricemia. However, these associations failed to reach significance in mutually adjusted analysis. Seafood intake was associated with higher prevalence of hyperuricemia. The ORs for quintiles of seafood intake (including fish and shellfish) were 1.00, 1.49, 1.35, 1.34, and 1.56 (p for trend: 0.01). An inverse association approaching significance between soy food consumption and hyperuricemia was observed (ORs: 1.00, 0.90, 0.70, 0.89, and 0.77 for quintiles of intake; p for trend: 0.07). No associations between consumption of purine-rich vegetables or meat and prevalence of hyperuricemia were observed.

CONCLUSIONS

Our data suggest a direct association between seafood consumption and hyperuricemia and an inverse association between consumption of soy food and hyperuricemia among middle-aged, Chinese men.

Is the apolipoprotein E4 allele always hazardous? Serum uric acid level as a conflict

Hyperuricemia, dyslipidemia, and apolipoprotein E (apoE) polymorphism are risk factors for cardiovascular diseases (CVDs). This study sought to determine the association of apoE gene polymorphism with hyperuricemia and dyslipidemia in young healthy people. Association of serum uric acid (SUA) and serum lipids with apoE was studied by analysis of variance in 198 healthy southern Iranian candidates. Subjects with an E2/E3 genotype had a lower cholesterol level in comparison with E3/E3 individuals. In addition, male E3/E4 subjects had a lower SUA level in comparison with other men. Lower cholesterol levels in E2 carriers mean a lower risk for CVDs, while SUA, as another risk factor for CVDs, in male E4 carriers was low. Regarding the higher risk for CVDs in men and the known role of SUA and apoE polymorphism in CVDs, it is not simple to guess the net effect of each one of these risk factors. This is the first report to study the association between SUA level and apoE in healthy men.

Effects of statin monotherapy versus statin plus ezetimibe combination on serum uric acid levels

BACKGROUND

Uric acid is considered a risk factor for cardiovascular disease (CVD). The effect of statins and ezetimibe on serum uric acid levels has not been yet clarified.

OBJECTIVE

To compare the effect of simvastatin/ezetimibe 10/10 mg, simvastatin 40 mg, and rosuvastatin 10 mg daily on serum uric acid levels in patients with dyslipidemia.

METHODS

This was a prospective, randomized, open-label, blinded end point (PROBE) study. Following a 3-month dietary intervention, patients with hypercholesterolemia received simvastatin/ezetimibe 10/10 mg or simvastatin 40 mg or rosuvastatin 10 mg. Changes in serum levels of uric acid and fractional renal excretion of uric acid as well as changes in electrolyte and renal function parameters were assessed after 12 weeks of treatment.

RESULTS

One hundred fifty-three patients (56 male) were included. At week 12, a significant reduction in serum uric acid levels was seen in all treatment groups (simvastatin/ezetimibe 10/10 mg: -3.8%, simvastatin 40 mg: -5.7%, and rosuvastatin 10 mg: -3.8%; P < .05 compared with baseline; P = not significant [NS] for comparison between groups). Fractional excretion of uric acid nonsignificantly increased in all groups (simvastatin/ezetimibe 10/10 mg: +6.8%, simvastatin 40 mg: +6.8%, and rosuvastatin 10 mg: +5.9%). The reduction in serum uric acid levels correlated with the increase in fractional excretion of uric acid and baseline uric acid levels. Renal function parameters as well as serum levels and fractional excretions of electrolytes remained unchanged in all groups. Changes in serum lipids were similar across groups.

CONCLUSION

Simvastatin/ezetimibe 10/10 mg, simvastatin 40 mg, and rosuvastatin 10 mg exhibit a similar uric acid-lowering effect.

Relationships among hyperuricemia, endothelial dysfunction and cardiovascular disease: molecular mechanisms and clinical implications

Uric acid is the end product of purine metabolism. Its immediate precursor, xanthine, is converted to uric acid by an enzymatic reaction involving xanthine oxidoreductase. Uric acid has been formerly considered a major antioxidant in human plasma with possible beneficial anti-atherosclerotic effects. In contrast, studies in the past two decades have reported associations between elevated serum uric acid levels and cardiovascular events, suggesting a potential role for uric acid as a risk factor for atherosclerosis and related diseases. In this paper, the molecular pattern of uric acid formation, its possible deleterious effects, as well as the involvement of xanthine oxidoreductase in reactive oxygen species generation are critically discussed. Reactive oxygen species contribute to vascular oxidative stress and endothelial dysfunction, which are associated with the risk of atherosclerosis. Recent studies have renewed attention to the xanthine oxidoreductase system, since xanthine oxidoreductase inhibitors, such as allopurinol and oxypurinol, would be capable of preventing atherosclerosis progression by reducing endothelial dysfunction. Also, beneficial effects could be obtained in patients with congestive heart failure. The simultaneous reduction in uric acid levels might contribute to these effects, or be a mere epiphenomenon of the drug action. The molecular mechanisms involved are discussed.

A distinct metabolic signature predicts development of fasting plasma glucose

Background

High blood glucose and diabetes are amongst the conditions causing the greatest losses in years of healthy life worldwide. Therefore, numerous studies aim to identify reliable risk markers for development of impaired glucose metabolism and type 2 diabetes. However, the molecular basis of impaired glucose metabolism is so far insufficiently understood. The development of so called 'omics' approaches in the recent years promises to identify molecular markers and to further understand the molecular basis of impaired glucose metabolism and type 2 diabetes. Although univariate statistical approaches are often applied, we demonstrate here that the application of multivariate statistical approaches is highly recommended to fully capture the complexity of data gained using high-throughput methods.

Methods

We took blood plasma samples from 172 subjects who participated in the prospective Metabolic Syndrome Berlin Potsdam follow-up study (MESY-BEPO Follow-up). We analysed these samples using Gas Chromatography coupled with Mass Spectrometry (GC-MS), and measured 286 metabolites. Furthermore, fasting glucose levels were measured using standard methods at baseline, and after an average of six years. We did correlation analysis and built linear regression models as well as Random Forest regression models to identify metabolites that predict the development of fasting glucose in our cohort.

Results

We found a metabolic pattern consisting of nine metabolites that predicted fasting glucose development with an accuracy of 0.47 in tenfold cross-validation using Random Forest regression. We also showed that adding established risk markers did not improve the model accuracy. However, external validation is eventually desirable. Although not all metabolites belonging to the final pattern are identified yet, the pattern directs attention to amino acid metabolism, energy metabolism and redox homeostasis.

Conclusions

We demonstrate that metabolites identified using a high-throughput method (GC-MS) perform well in predicting the development of fasting plasma glucose over several years. Notably, not single, but a complex pattern of metabolites propels the prediction and therefore reflects the complexity of the underlying molecular mechanisms. This result could only be captured by application of multivariate statistical approaches. Therefore, we highly recommend the usage of statistical methods that seize the complexity of the information given by high-throughput methods.

High serum uric acid level and low urine pH as predictors of metabolic syndrome: a retrospective cohort study in a Japanese urban population

The objective of this study was to evaluate whether hyperuricemia, acidic urine, or their combination predicts metabolic syndrome (MetS). In study 1, 69,094 subjects who received a general health checkup between 1985 and 2005 were included in a cross-sectional study of serum uric acid (SUA) and urine pH in relation to MetS. In study 2, the association of SUA and urine pH with MetS development over a 5-year period was evaluated in 5617 subjects with body mass index less than 25 kg/m(2) at the first examination. In study 1, higher SUA and lower urine pH were both positively correlated to MetS status (P < .001). The combination of high SUA and low urine pH was significantly associated with higher MetS prevalence compared with the combination of low SUA and high urine pH (odds ratio, 3.383; 95% confidence interval [CI], 3.034-3.784 in men; odds ratio, 4.000; 95% CI, 2.992-5.452 in women). In study 2, the top quartile of SUA levels was associated with higher MetS development compared with the bottom quartile during the 5-year period in men (hazard ratio [HR], 1.793; 95% CI, 1.084-2.966; P = .023). In women, the HR was 3.732 (95% CI, 0.391-35.62; P = .252) for the upper vs the lower half of SUA levels. For urine pH, the HR was 1.955 (95% CI, 1.089-3.509; P = .025) for the bottom vs the top quartile in men. A likelihood ratio test confirmed that high SUA and low urine pH act synergistically in the development of MetS. High SUA, low urine pH, and their combination are predictive risk factors for MetS development.

Uric acid is an independent risk factor for carotid atherosclerosis in a Japanese elderly population without metabolic syndrome

Background

Carotid intima-media thickness (IMT) is an useful surrogate marker of cardiovascular disease. Associations between uric acid (UA), metabolic syndrome (MetS) and carotid IMT have been reported, but findings regarding the relationship have been inconsistent.

Methods

A total of 1,579 Japanese elderly subjects aged ≥65 years {663 men aged, 78 ± 8 (mean ± standard deviation) years and 916 women aged 79 ± 8 years} were divided into 4 groups according to UA quartiles. We first investigated the association between UA concentrations and confounding factors including MetS; then, we assessed whether there is an independent association of UA with carotid IMT and atherosclerosis in participants subdivided according to gender and MetS status.

Results

Carotid IMT was significantly increased according to the quartiles of UA in both genders without MetS and women with MetS. Multivariate logistic regression analysis showed that odds ratio (OR) {95% confidence interval (CI)} in men for carotid atherosclerosis was significantly increased in the third (OR, 1.75; 95% CI, 1.02-3.02), and fourth quartiles (OR, 2.01; 95% CI, 1.12-3.60) of UA compared with that in the first quartile of UA, and the OR in women was significantly increased in the fourth quartile (OR, 2.10; 95% CI, 1.30-3.39). Similarly, the ORs were significantly associated with increasing quartiles of UA in both genders without MetS, but not necessarily increased in those with MetS.

Conclusions

UA was found to be an independent risk factor for incidence of carotid atherosclerosis in both genders without MetS.

Determinants of blood uric acid levels in a dyslipidemic Arab population

OBJECTIVES

The objective of this study was to explore the relationships between circulating uric acid and lipid levels and components of the metabolic syndrome (MetS) in Arab dyslipidemic patients, a group already at high coronary artery disease risk.

SUBJECTS AND METHODS

The medical records of 1,229 subjects (632 men, 597 women) referred for treatment of dyslipidemia and followed up for at least 12 months were reviewed. Serum levels of uric acid and lipids (total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein) and other variables in the National Cholesterol Education Program ATP III criteria definition of MetS were assessed at initial presentation and every 4- 6 months, under specific lipid-lowering treatment (statins and/or fibrates), in each of the subjects. Their respective associations were explored by appropriate logistic regression techniques with control for confounding risk factors, including age, gender and body mass index.

RESULTS

306 subjects (24.9%) of the study population were hyperuricemic; they were more likely to be men, obese and diabetic. Also the serum uric acid level (mean ± SD) was greater in men with MetS compared with men without (377.0 ± 98.0 vs. 361.6 ± 83.1 μmol/l, p < 0.05), an observation not reproduced in women. Uric acid levels had significant associations with the presence of fasting hyperglycemia, hypertension and large waist circumference (WC) in men, but only with large WC in women. With statin treatment, uric acid levels decreased by 10% within 1 year of treatment; with fibrates, uric acid levels remained unchanged or slightly increased.

CONCLUSION

The data showed that hyperuricemia is common in dyslipidemic patients in Kuwait, where its important determinants are male sex, obesity, diabetes and statin treatment.

IMproving the imPlemEntation of cuRrent guidelines for the mAnagement of major coronary hearT disease rIsk factors by multifactorial interVEntion. The IMPERATIVE renal analysis

INTRODUCTION

The short-term effects of multifactorial intervention for cardiovascular disease (CVD) prevention on renal function and serum uric acid (SUA) levels in patients with stage 3 chronic kidney disease (CKD) and multiple CVD risk factors are unclear. The aim of the study was to prospectively assess these effects.

MATERIAL AND METHODS

This post hoc analysis of 5 "best practice" studies involved patients with multiple CVD risk factors. Estimated glomerular filtration rate (eGFR) was assessed using the Modification of Diet in Renal Disease (MDRD) formula. Among the 4,153 patients, 1,235 (29.7%) had stage 3 CKD (eGFR between 30 and 59 ml/min/1.73 m(2)). A baseline visit was followed by a concerted effort from previously trained physicians to improve adherence to lifestyle advice and optimize drug treatment, including a statin, for all vascular risk factors. After 6 months eGFR and SUA levels were re-evaluated.

RESULTS

The intervention improved compliance to lifestyle measures and increased the use of evidence-based medication, including a statin. There was also a 5.6% increase in eGFR (p < 0.001) in patients with stage 3 CKD and a 6.1% reduction in SUA levels (p < 0.001). Among patients with stage 3 CKD, 127 (10.3%) improved to stage 2 CKD and 9 (0.7%) advanced to stage 4 CKD by the end of the 6-month study period. There were no major side-effects.

CONCLUSIONS

Multitargeted intervention, including a statin, may improve renal function and reduce SUA levels within 6 months, thus offsetting 2 potential CVD risk factors in high-risk patients.

Losartan therapy and hyperuricemia correction in patients with metabolic syndrome and arterial hypertension

Aim. To assess the potential of the angiotensin II receptor antagonist losartan for the correction of hyperuricemia (HU) in patients with arterial hypertension (AH) and metabolic syndrome (MS). Material and methods. This open, randomised, controlled comparative study in parallel groups included 60 AH patients with MS and HU. The patients received losartan or standard therapy for 12 weeks. Results. Throughout the follow-up period, no significant difference in antihypertensive effect was observed between the losartan and standard therapy groups. Losartan group patients demonstrated a more pronounced decrease in uric acid levels (-34,7 % vs. -7,8 % in the standard therapy group; p<0,05). In addition, losartan therapy, compared to the standard treatment, was associated with improved vascular elasticity, as manifested by the pulse wave velocity decrease (-27,8 % vs. -8,1 % for carotid-femoral index, and -30,2 % vs. -12,6 % for carotidradial index, respectively; both p<0,05).

Serum Uric Acid

Serum uric acid (SUA) is a potential risk factor for atherosclerosis. We assessed the relationship between SUA and subclinical atherosclerosis in Korean men (n = 3010). Multidetector computed tomography (MDCT) and ultrasonographic measurements of coronary artery calcification (CAC) and carotid intima–media thickness (cIMT), respectively, are markers of subclinical atherosclerosis. Odds ratios (ORs) of CAC score and cIMT across SUA levels were 1.101 ( P = .046) and 1.266 ( P = .002), respectively, after adjustment for several variables. The independent association between CAC and cIMT was observed (OR = 1.231, P < .001). Serum uric acid was independently associated with metabolic syndrome (MetS) with an OR of 1.415 ( P < .001). Metabolic syndrome was only independently associated with cIMT, with an OR of 2.103 ( P = .003). High-sensitivity C-reactive protein was positively correlated with SUA ( r = .125, P < .001). Serum uric acid level is independently associated with CAC, cIMT, and MetS in Korean men.

Increased serum levels of uric acid are associated with sudomotor dysfunction in subjects with type 2 diabetes mellitus

The aim of this paper was to assess serum uric acid (SUA) levels in patients with type 2 diabetes mellitus (T2DM) with or without sudomotor dysfunction (evaluated by the Neuropad test). We included 36 T2DM patients with sudomotor dysfunction (group A: mean age 63.1 ± 2.6 years) and 40 age-, gender-, renal function- and T2DM duration-matched patients without sudomotor dysfunction (group B: mean age 62.1 ± 3.1 years). SUA was significantly higher in group A (P < 0.001). There was a significant correlation between SUA and Neuropad time to colour change in both groups (group A: r_s = 0.819, P < 0.001; group B: r_s = 0.774, P < 0.001). There was also a significant positive correlation between SUA and CRP in both groups (group A: r_s = 0.947, P < 0.001; group B: r_s = 0.848, P < 0.001). In conclusion, SUA levels were higher in T2DM patients with sudomotor dysfunction than those without this complication. The potential role of SUA in sudomotor dysfunction merits further study.

Association between the changes in renal function and serum uric acid levels during multifactorial intervention and clinical outcome in patients with metabolic syndrome. A post hoc analysis of the ATTEMPT study

AIM

To assess the effects of long-term multifactorial intervention on renal function and serum uric acid (SUA) levels and their association with estimated cardiovascular disease (eCVD) risk and actual CVD events.

METHODS

This prospective, randomized, target-driven study included 1123 subjects (45.6% men, age 45-65 years) with metabolic syndrome (MetS) but without diabetes or CVD. Patients were randomized to multifactorial treatment. Atorvastatin was titrated from 10-80 mg/day aiming at a low density lipoprotein cholesterol (LDL-C) target of <100 mg/dl (group A) or an LDL-C target of <130 mg/dl (group B). Changes in estimated glomerular filtration rate (eGFR) and SUA levels were recorded in all patients and in the subgroup with stage 3 chronic kidney disease (CKD; eGFR = 30-59 ml/min/1.73 m(2); n = 349). We used ANOVA to compare changes within the same group, unpaired Student t-test to compare results between groups at specific time points, and log-rank test to compare event free survival.

RESULTS

The eCVD-risk reduction was greater in group A. In the overall study population, eGFR increased by 3.5% (p < 0.001) and SUA levels fell by 5.6% (p < 0.001). In patients from group A with stage 3 CKD (group A1; n = 172), eGFR increased by 11.1% (p < 0.001) from baseline and by 7.5% (p < 0.001) in group B1 (n = 177; p < 0.001 vs. the change in group A1). The corresponding fall in SUA levels was 10.7% in group A1 (p < 0.001 vs. baseline) and 8.3% in group B1 (p < 0.001 vs. baseline and group A1). These changes were mainly attributed to atorvastatin treatment. Among the CKD stage 3 patients there were no CVD events in group A1, while 6 events occurred in group B1 (p = 0.014).

CONCLUSIONS

Multifactorial intervention in patients with MetS without established CVD improved renal function and reduced SUA levels. These changes were more prominent in stage 3 CKD patients and might have contributed to the reduction in eCVD risk and clinical events. Original study registration number [ClinicalTrials.gov ID: NCT00416741].

Serum uric acid in relation with the metabolic syndrome components and adiponectin levels in Lebanese University students

BACKGROUND

The relation between serum uric acid (SUA) and metabolic syndrome (MetS) parameters has never been studied in a young Middle-Eastern population. In addition, the relation between SUA and adiponectin was poorly studied.

METHODS

We looked at the relation between SUA, and both adiponectin and MetS components in 381 randomly selected Lebanese university students (201 males and 180 females).

RESULTS

SUA was positively correlated with body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), waist circumference (WC), fasting blood glucose (FPG), triglycerides, total and LDL-cholesterol, and homeostasis model assessment (HOMA) index (p<0.001 for all variables, p<0.01 for FPG) and inversely correlated with HDL-cholesterol and adiponectin (p<0.001 for both variables). In men, SUA was positively correlated with BMI, WC, SBP, DBP, FPG, triglycerides, total and LDL-cholesterol, and HOMA index and inversely correlated with adiponectin (p<0.001 for all variables, p<0.05 for adiponectin); these correlations persisted after BMI adjustment, for WC, FPG, triglycerides, total-cholesterol, LDL-cholesterol, and HOMA index. In women, SUA was positively correlated with total and LDL-cholesterol (p<0.001), independently of BMI. In a multiple regression analysis, SUA was independently associated with WC, triglycerides, total cholesterol, HDLcholesterol and adiponectin in the overall population while, in men, it was associated with triglycerides, total-cholesterol, and WC.

CONCLUSION

Our results suggest, in young adults, a gender difference in the relation between SUA and both adiponectin and MetS parameters. In addition, we observed in both genders a strong relation of SUA with total cholesterol. Further studies are needed in larger populations in order to elucidate these findings.

Prevalence of Metabolic Syndrome According to Different Definitions in a Hypertensive Population

Aims: The metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease (CVD) and diabetes mellitus (DM). Several definitions of MetS have been proposed. The aim of the present study was to estimate and compare the prevalence of MetS according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), American Heart Association-National Heart Lung and Blood Institute (AHA-NHLBI), International Diabetes Federation (IDF) and the more recent Joint Interim Statement (JIS) definitions in patients attending a hypertension clinic. Methods: The records of patients referred to the hypertension clinic at the University Hospital (Heraklion, Crete) from January 2001 to June 2009 were screened retrospectively. A total 384 patients (146 men) were included in the study. Results: The prevalence of MetS according to the IDF and JIS definitions was significantly higher compared with that of the NCEP ATP III in both genders (IDF: P = .009 and P = .002, JIS: P = .002 and P = 0.001 for men and women, respectively); this was the case for the AHA-NHLBI definition only among women ( P = .03). All MetS components differed significantly ( P from < .0001 to .02) between patients with and without MetS for all definitions. Conclusions: The prevalence of MetS varies considerably depending on the definition used in a hypertensive population in a Mediterranean country. These differences will influence risk assessment.

Down-regulation of hepatic urea synthesis by oxypurines: xanthine and uric acid inhibit N-acetylglutamate synthase

We previously reported that isobutylmethylxanthine (IBMX), a derivative of oxypurine, inhibits citrulline synthesis by an as yet unknown mechanism. Here, we demonstrate that IBMX and other oxypurines containing a 2,6-dione group interfere with the binding of glutamate to the active site of N-acetylglutamate synthetase (NAGS), thereby decreasing synthesis of N-acetylglutamate, the obligatory activator of carbamoyl phosphate synthase-1 (CPS1). The result is reduction of citrulline and urea synthesis. Experiments were performed with (15)N-labeled substrates, purified hepatic CPS1, and recombinant mouse NAGS as well as isolated mitochondria. We also used isolated hepatocytes to examine the action of various oxypurines on ureagenesis and to assess the ameliorating affect of N-carbamylglutamate and/or l-arginine on NAGS inhibition. Among various oxypurines tested, only IBMX, xanthine, or uric acid significantly increased the apparent K(m) for glutamate and decreased velocity of NAGS, with little effect on CPS1. The inhibition of NAGS is time- and dose-dependent and leads to decreased formation of the CPS1-N-acetylglutamate complex and consequent inhibition of citrulline and urea synthesis. However, such inhibition was reversed by supplementation with N-carbamylglutamate. The data demonstrate that xanthine and uric acid, both physiologically occurring oxypurines, inhibit the hepatic synthesis of N-acetylglutamate. An important and novel concept emerging from this study is that xanthine and/or uric acid may have a role in the regulation of ureagenesis and, thus, nitrogen homeostasis in normal and disease states.

The relationship between uric acid and metabolic syndrome in normal glucose tolerance and normal fasting glucose subjects

Elevated serum uric acid (SUA) concentrations have been suggested to associate with metabolic syndrome (MetS) and its components. However, limited information is available regarding the relationship between SUA and MetS in subjects with normal glucose levels. A total of 501 subjects with normal fasting glucose and normal glucose tolerance were included in the study. Anthropometrical and biochemical parameters were examined using standard methods. The updated NECP criteria were used to define the MetS. Values of SUA above the sex-specific percentile 75 were used to define hyperuricemia. The prevalence of general and abdominal obesity, hypertension, hypertriglyceridemia, low-HDL, smokers, MetS and insulin resistance was significantly greater in the fourth SUA quartile. Multiple regression indicated that SUA was independently predicted by BMI, triglyceride and 2 h glucose in women, and BMI, triglyceride, 2 h glucose and cholesterol in men. Logistic regression analysis showed that the obesity, hypertriglyceridemia, MetS and insulin resistance were independent determinants of hyperuricemia in women. In men, hyperuricemia was associated with the obesity, hypertriglyceridemia and hypercholesterolemia. Factor analysis yielded three factors interpreted as weight/waist, blood pressure and lipid/glucose. Including SUA in the model did not affect total variance of factor analysis. Our results indicate that SUA is associated with MetS and its components even in subjects with normal glucose levels. General obesity was the major determinant of hyperuricemia in this population. The data from this study do not show the contribution of SUA as an additional component of the MetS.

Peripheral neuropathy is associated with increased serum levels of uric acid in type 2 diabetes mellitus

We assessed serum uric acid (SUA) levels in patients with type 2 diabetes mellitus (T2DM) with or without peripheral neuropathy (diagnosed by the Neuropathy Disability score [NDS]). We enrolled 64 patients with T2DM with peripheral neuropathy (group A: 31 men, mean age 63.0 ± 2.8 years) and 66 age-, gender-, renal function- and T2DM duration-matched patients without neuropathy (group B: 32 men, mean age 62.4 ± 3.1 years). Serum uric acid was significantly higher in group A (P < .001). There was a significant correlation between SUA and NDS in both groups (group A: r(s) = .93, P < .001; group B: r( s) = .95, P < .001). C-reactive protein (CRP) was also significantly higher in group A (P < .001) and correlated significantly with SUA in both groups (group A: r(s) = .93, P < .001; group B: r(s) = .87, P < .001). Serum uric acid is increased in patients with T2DM with neuropathy versus those without. Whether SUA is involved in the pathogenesis of T2DM peripheral neuropathy remains to be established.

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.

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.

Prevalence and determinants of hyperuricemia in middle-aged, urban Chinese men

BACKGROUND

Hyperuricemia is associated with metabolic syndrome and has emerged as a marker for both type 2 diabetes and cardiovascular disease. We estimated the prevalence and lifestyle risk factors of hyperuricemia in middle-aged, urban Chinese men.

METHODS

The study included 3,978 urban Chinese men 40-74 years of age from a population-based cohort study, the Shanghai Men's Health Study, who were free of type 2 diabetes at baseline and had provided fasting blood samples. Uric acid concentrations were measured by the uricase method. Hyperuricemia was defined as >7.0 mg/dL. Anthropometric measurements and information on lifestyle factors and disease history were collected by in-person interviews.

RESULTS

One quarter of the study subjects had hyperuricemia. Participants with metabolic syndrome had a higher prevalence of hyperuricemia. Body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, and weight gain (since age 20) were positively associated with the prevalence of hyperuricemia. Physical activity was inversely related to the prevalence of hyperuricemia. The odds ratios for hyperuricemia for quintiles of nonoccupational physical activity were 1.00, 0.80, 0.73, 0.75, and 0.57 (P trend <0.001). Participants with hyperuricemia were less likely to be current smokers, but were more likely to drink alcohol regularly. Beer consumption was associated with higher risk of hyperuricemia compared with consumption of wine or liquor.

CONCLUSIONS

In this representative sample of middle-aged, urban Chinese men, hyperuricemia is highly prevalent. Obesity, weight gain in adulthood, and alcohol intake were associated with a higher prevalence of hyperuricemia, whereas daily physical activity and smoking were inversely related to the prevalence of hyperuricemia.

Postprandial plasma adiponectin response is reduced in prepubertal premature pubarche girls

The association between premature pubarche (PP) and metabolic syndrome is controversial and not supported by some authors. The aim of this study was to determine insulin resistance syndrome, plasma adiponectin, and fatty acid profile in PP girls to discern potential confounder variables and markers of metabolic disturbances. We studied 22 prepubertal girls with a diagnosis of PP and 20 healthy controls who differed in body mass index (BMI) (19.33 +/- 0.71 vs 17.30 +/- 0.60). We evaluated insulin resistance syndrome components and postprandial response of adiponectin, nonesterified fatty acids, and fatty acid profile after consumption of a standardized breakfast. No lipid disturbances were detected in the PP group. High-density lipoprotein to low-density lipoprotein cholesterol ratio tended to be lower in PP girls (P = .052), but this effect disappeared when data were adjusted for both BMI and age (P = .480). Insulin levels tended to be higher at 2 hours in PP girls, who showed significantly higher C-peptide area under the curve. In contrast, adiponectin at 3 hours after the meal and postprandial adiponectin area under the curve were significantly lower. The PP girls showed significantly higher percentages of eicosapentaenoic acid in total plasma and plasma phospholipids. No differences were found in the postprandial fatty acid clearance rate. In conclusion, PP girls and controls differed in postprandial plasma adiponectin response and in postprandial plasma C-peptide response after both BMI and age adjustment. Cholesterol plasma disturbances were mainly attributable to their higher BMI, although n-3 polyunsaturated fatty acids were higher because of the PP.

Psychosocial factors and metabolic parameters: is there any association in elderly people? The Massa Lombarda Project

OBJECTIVE

Several studies claim that psychophysical stress and depression contribute significantly to cardiovascular disease (CVD) development. The aim of our research is to discover and analyse a possible relationship between two psychosocial disorders (depression and perceived mental stress) and traditional cardiovascular risk markers.

METHODS

We selected 106 subjects (58 males and 48 females), mean age 79.5 +/- 3.8-years old, from the Massa Lombarda Project, an epidemiological study, including 7000 north Italian adult subjects. We carried out anamnesis, clinical and blood tests. Then, we administered the Perceived Stress Questionnaire (PSQ range score 0-1) and the Self-Rating Depression Scale (SRDS range score 50-70 Z), as validated instruments for depression and stress evaluation, which focus on the individual's subjective perception and emotional response. Statistical descriptive and inferential analyses of data collected were performed.

RESULTS

The multiple linear regression analysis showed a negative correlation between PSQ index score and uric acid, low-density lipoprotein cholesterol (LDL-c), body mass index (BMI), systolic and diastolic blood pressure values, a positive and statistically significant correlation between PSQ index score and triglycerides (p < 0.05). We found an inverse relationship between Zung SRDS score and LDL-c, uric acid, glucose waist circumference values, this correlation was significant only for uric acid (p < 0.01). Besides, a positive and significant correlation between Zung SRDS and triglycerides (p < 0.05) was observed.

CONCLUSION

We suppose that psycho-emotional stress and depression disorder, often diagnosed in elderly people, may influence different metabolic parameters (triglycerides, uric acid and BMI) that are involved in the complex process of metabolic syndrome.

The impact of obstructive sleep apnea on metabolic and inflammatory markers in consecutive patients with metabolic syndrome

BACKGROUND

Obstructive Sleep Apnea (OSA) is tightly linked to some components of Metabolic Syndrome (MetS). However, most of the evidence evaluated individual components of the MetS or patients with a diagnosis of OSA that were referred for sleep studies due to sleep complaints. Therefore, it is not clear whether OSA exacerbates the metabolic abnormalities in a representative sample of patients with MetS.

METHODOLOGY/PRINCIPAL FINDINGS

We studied 152 consecutive patients (age 48+/-9 years, body mass index 32.3+/-3.4 Kg/m2) newly diagnosed with MetS (Adult Treatment Panel III). All participants underwent standard polysomnography irrespective of sleep complaints, and laboratory measurements (glucose, lipid profile, uric acid and C-reactive protein). The prevalence of OSA (apnea-hypopnea index>or=15 events per hour of sleep) was 60.5%. Patients with OSA exhibited significantly higher levels of blood pressure, glucose, triglycerides, cholesterol, LDL, cholesterol/HDL ratio, triglycerides/HDL ratio, uric acid and C-reactive protein than patients without OSA. OSA was independently associated with 2 MetS criteria: triglycerides: OR: 3.26 (1.47-7.21) and glucose: OR: 2.31 (1.12-4.80). OSA was also independently associated with increased cholesterol/HDL ratio: OR: 2.38 (1.08-5.24), uric acid: OR: 4.19 (1.70-10.35) and C-reactive protein: OR: 6.10 (2.64-14.11). Indices of sleep apnea severity, apnea-hypopnea index and minimum oxygen saturation, were independently associated with increased levels of triglycerides, glucose as well as cholesterol/HDL ratio, uric acid and C-reactive protein. Excessive daytime sleepiness had no effect on the metabolic and inflammatory parameters.

CONCLUSIONS/SIGNIFICANCE

Unrecognized OSA is common in consecutive patients with MetS. OSA may contribute to metabolic dysregulation and systemic inflammation in patients with MetS, regardless of symptoms of daytime sleepiness.

Serum uric acid does not predict cardiovascular or all-cause mortality in type 2 diabetes: the Fremantle Diabetes Study

AIMS/HYPOTHESIS

To determine whether serum uric acid: (1) is associated with cardiovascular disease (CVD) death and/or all-cause mortality in type 2 diabetes; and (2) consistent with published data, predicts these outcomes in older patients and those of southern European ethnicity.

METHODS

We studied those 1,268 (98%) of 1,294 type 2 participants in the observational Fremantle Diabetes Study who had a fasting serum uric acid measured at baseline. Mortality data were collected over a mean (+/-SD) 10.3 +/- 3.9 years. Cox proportional hazards modelling was used to determine independent baseline predictors of CVD and all-cause death including fasting serum uric acid as a continuous variable and quartiles.

RESULTS

During follow up, 525 deaths occurred (41.4% of the cohort) of which 271 (51.6%) were attributed to CVD. In univariate analyses, patients in the highest uric acid quartile had the greatest CVD and all-cause mortality (p = 0.007 and p = 0.001). After adjustment for significant variables in the most parsimonious model, baseline serum uric acid was not an independent associate of CVD or all-cause mortality whether entered as a continuous variable (HR 1.11 [95% CI 0.96-1.27] and 1.10 [95% CI 0.98-1.22] for a 0.1 mmol/l increase, respectively) or as quartiles (p > 0.10). Analyses of 638 patients >65 years of age and 231 of southern European ethnicity produced similar results.

CONCLUSIONS/INTERPRETATION

Serum uric acid was not an independent predictor of CVD or all-cause mortality in our community-based type 2 patients. Fasting serum uric acid concentrations do not appear to be prognostically useful in type 2 diabetes.