Potential role of uric Acid as a risk factor for cardiovascular disease

Pharmacological screening of fenofibrate-loaded solid dispersion in fructose-induced diabetic rat

OBJECTIVES

Hyperlipidaemia is a common phenomenon in diabetes mellitus. Fenofibrate (FF) is a good candidate for the treatment of lipid abnormalities in patients with type 2 diabetes. But the bioavailability as well as therapeutic efficacy of this drug is limited to its dissolution behaviour. Here, the authors assess the therapeutic efficacy of a newly formulated solid dispersion of fenofibrate (SDF) having enhanced dissolution profiles in contrast to pure FF using fructose-induced diabetic rat model.

METHODS

Fructose-induced diabetic rat model was developed to assess the pharmacological efficacy of the formulated SDF, and the results were compared with the effects of conventional FF therapy.

KEY FINDINGS

The 14 days treatment showed better improvement in lipid-lowering potency of SDF than pure FF. SDF containing one-third dose of pure FF showed similar effect in terms of triglyceride, total cholesterol and low-density lipoprotein lowering efficacy, whereas increased high-density lipoprotein at same extent. The similar dose of SDF produced more prominent effect than FF. Histological studies also demonstrated the enhanced lipid clearance from liver by SDF than FF that was concordant with the biochemical results.

CONCLUSIONS

This newly formulated SDF would be a promising alternative for conventional fenofibrate in treating hyperlipidaemia.

Sex-linked changes and high cardiovascular risk markers in the mature progeny of father, mother, or both father and mother consuming a high-fructose diet

OBJECTIVES

The aim of this study was to observe the developmental origins of health and disease affecting offspring owing to the consumption of a diet containing high fructose by the father or mother or both, considering that progeny only received a control diet during postnatal life.

METHODS

Male (future father) and female (future mother) C57 BL/6 mice were fed a high-fructose diet (HFru; 45% energy) or a control diet (C) for 8 wk before mating until lactation. The offspring was termed according to sex, maternal diet (first acrostic), and paternal diet (second acrostic); and received a balanced control diet until 3-mo of age when they were sacrificed. Body mass (BM), plasmatic leptin, adiponectin, uric acid, and systolic blood pressure (BP) were measured in mature offspring.

RESULTS

Fasting glycemia and insulin were elevated in HFru fathers and mothers. Although there was no change in BM, fasting glycemia, or insulin of the offspring, those of HFru fathers, HFru mothers, and HFru fathers and mothers presented higher genital fat pad, leptin, uric acid, and BP, and lower adiponectin. The values of leptin and BP were maximized when both parents consumed a HFru diet. Also, there was sexual dimorphism in most of the variables, with the male offspring being affected to a greater extent than the females.

CONCLUSIONS

Consumption of a fructose-rich diet by the father, the mother, or both negatively affected the adipokines, BP, and uric acid concentrations of mature offspring, with males being more affected than females. It is significant to consider that high BP and plasmatic uric acid correspond to markers of elevated cardiovascular risk in the progeny.

The relationship between serum uric acid and lipid profile in Bangladeshi adults

Background

Although the link between elevated uric acid and metabolic syndrome has been reported in some studies; the relationship of serum uric acid (SUA) with lipid profile has not well studied or little is known so far. This study was conducted to assess the relationship between SUA and lipid profile among the general adults in Bangladesh.

Methods

In total, 280 blood samples were collected from general adult participants (male, n = 150 and female, n = 130) and analyzed for serum lipid profile (TC, TG, HDL and LDL) and SUA levels. The study subjects were divided by quartiles based on SUA levels (Q1: ≤225 μmol/L, Q2: 226–285 μmol/L, Q3: 286–340 μmol/L and Q4: > 340 μmol/L). Linear regression modeling was used to evaluate the relationship between SUA and lipid levels.

Results

The prevalence of hyperuricemia was 9.2% in males and 10.4% in females. The mean level of SUA was significantly higher in male (317 ± 90 μmol/L) than in the female (255 ± 65 μmol/L) subjects (p < 0.001). An increasing trend for elevated lipid profile was observed in both gender with increasing levels of SUA in the quartiles (p < 0.05). In regression analysis, a significant positive correlation was found between SUA and TG, TC and LDL (p < 0.01) while an inverse correlation was observed between SUA and HDL (p < 0.01). After adjusting for potential confounders, lipid profile was linearly associated with SUA levels (p < 0.01 for trend).

Conclusions

Present study showed a significant positive relationship for SUA with TG, TC and LDL levels, and an inverse relationship for SUA with HDL. Early prevention of hyperuricemia and dyslipidemia may be helpful to reduce the incidence of associated cardiovascular diseases.

Long-term prognostic role of uric acid in patients with ST-elevation myocardial infarction and renal dysfunction

Patients with renal impairment have decreased excretion of uric acid, thus being particularly prone to having elevated serum uric acid concentrations. No data are available on the long-term prognostic role of uric acid in patients with ST-elevation myocardial infarction (STEMI) and renal dysfunction, submitted to percutaneous coronary intervention (PCI). We therefore prospectively assessed, in 329 patients with STEMI and renal dysfunction (admission estimated glomerular filtration rate <60 ml/min/1.73 m), all submitted to PCI, whether uric acid levels are associated with increased mortality at 1-year postdischarge follow-up.Patients in the third tertile of uric acid showed a higher BMI (P = 0.014), a higher incidence of hypertension (P = 0.029), and two or more comorbidities (P = 0.034). The highest incidence of bleeding and of acute kidney injury was detectable in patients in the third tertile (P = 0.011 and P < 0.001, respectively) who showed the highest mortality rate at 1-year postdischarge follow-up (P = 0.008). At Cox regression analysis, uric acid was an independent predictor of 1-year postdischarge mortality (hazard ratio 1.26, 95% confidence interval 1.06-1.51, P = 0.011).In STEMI patients with estimated glomerular filtration rate below 60 ml/min/1.73 m treated with PCI, uric acid helps in identifying a subset of patients at a higher risk of bleeding and acute kidney injury. Increased uric acid is an independent prognostic risk factor for 1-year mortality. Further studies performed in larger cohorts of patients are needed to confirm our findings and to evaluate whether lowering uric acid in these patients is beneficial.

Serum uric acid as a risk predictor for erectile dysfunction

INTRODUCTION

Serum uric acid (UA) is now beginning to be considered a risk predictor for cardiovascular diseases. However, little is known about the effect of hyperuricemia on the risk of developing other systemic vascular disorders, especially erectile dysfunction (ED).

AIM

To evaluate whether serum UA is a predicting factor for ED while adjusting for other common risk factors.

METHODS

Two hundred fifty-one patients aged 45.2 ± 10.1 years with newly diagnosed and documented ED and 252 age-matched participants without ED (aged 45.1 ± 8.4 years) were enrolled in this case-control study. Univariate and multivariate logistic regression analysis were performed to assess the effect of serum UA on ED; odds ratio (OR) and 95% confidence interval (CI) were calculated. Adjustments were made for potential confounding factors, including obesity, hypertension, diabetes, dyslipidemia, serum triglyceride, and smoking.

MAIN OUTCOME MEASUREMENT

Serum UA concentration and the distribution of potential ED risk factors (age, smoking, lipid profile, hypertension, obesity, and diabetes mellitus) were evaluated. Serum UA levels were organized into tertiles. The five-item International Index of Erectile Function was used to evaluate the presence and the severity of ED.

RESULTS

The mean serum UA levels in ED-positive and ED-negative groups were 6.12 ± 1.55 mg/dL and 4.97 ± 1.09 mg/dL, respectively (P < 0.001). On analysis of unadjusted variables, statistically significant differences were found for all variables, including serum UA, between ED-positive and ED-negative groups. After adjustment for major risk factors, a significant trend of increasing risk was found for serum UA concentration (OR 5.95, 95% CI 2.96-11.97; P < 0.001, comparing the highest with the lowest tertile). An increase of 1 mg/dL in serum UA level was associated with an approximately twofold increase in risk of ED (OR 2.07; 95% CI 1.63-2.64).

CONCLUSIONS

Our findings reveal that serum UA can be considered a risk predictor for ED. Furthermore, hyperuricemia can be regarded as an independent risk factor in addition to the established ones.

Association between serum uric acid level and metabolic syndrome

OBJECTIVES

Serum uric acid levels have been reported to be associated with a variety of cardiovascular conditions. However, the direct association between uric acid levels and metabolic syndrome remains controversial. Thus, we evaluated the association of serum uric acid levels and metabolic syndrome in a community-based cohort study in Korea.

METHODS

We performed cross-sectional analysis of baseline data of 889 males and 1491 females (aged 38 to 87) who participated in baseline examinations of the Korean Genome and Epidemiology Study: Kanghwa study. Blood samples were collected after at least an 8 hour fast. Uric acid quartiles were defined as follows: <4.8, 4.8-<5.6, 5.6-<6.5, ≥6.5 mg/dL in males; and <3.8, 3.8-<4.3, 4.3-<5.1, ≥5.1 mg/dL in females. Metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel III Criteria with adjusted waist circumference cutoffs (90 cm for males; 80 cm for females). The association between serum uric acid quartiles and metabolic syndrome was assessed using multivariate logistic regression.

RESULTS

The odds ratio for having metabolic syndrome in the highest versus lowest quartiles of serum uric acid levels was 2.67 (95% confidence interval [CI], 1.60 to 4.46) in males and 2.14 (95% CI, 1.50 to 3.05) in females after adjusting for age, smoking, alcohol intake, body mass index, total cholesterol, HbA1c, albumin, γ-glutamyltransferase, blood urea nitrogen, and log C-reactive protein. The number of metabolic abnormalities also increased gradually with increasing serum uric acid levels (adjusted p for trend < 0.001 in both sexes).

CONCLUSIONS

Higher serum uric acid levels are positively associated with the presence of metabolic syndrome in Korean males and females.

Uric acid in the early risk stratification of ST-elevation myocardial infarction

Controversy still exists about uric acid as a potential prognostic risk factor for outcomes in patients with acute myocardial infarction. We prospectively assessed, in 856 patients with ST-elevation myocardial infarction (STMI) consecutively admitted to our Intensive Cardiac Care Unit after primary percutaneous coronary intervention (PCI) whether uric acid (UA) levels are associated with in-hospital mortality and complications. Killip classes III-IV were more frequent in the 3° UA tertile that was associated with the highest values of peak Tn I (p = 0.005), NT-proBNP (p < 0.001), and fibrinogen (p = 0.036). Uric acid was associated with mortality (crude OR: 1.24; 95% CI 1.03-1.51; p = 0.025), but, when adjusted for Tn I and renal failure (as inferred by eGFR <60 ml/min/1.73 m(2)), uric acid lost its statistical significance, while Tn I (100 pg/ml step OR: 1.002; 95% CI 1.000-1.003; p = 0.007) and renal failure (OR 9.16; 95% CI 3.60-23.32; p < 0.001) were independent predictors for in-ICCU mortality. Uric acid remained as independent predictor for in-ICCU complications (1 mg/dl step OR: 1.11; 95% CI 1.01-1.21; p = 0.030) together with admission glycemia (1 g/dl step OR: 1.50; 95% CI 1.19-1.91; p < 0.001) and renal failure (OR: 1.46; 95% CI 0.99-2.16; p < 0.001). In STEMI patients submitted to PCI, increased uric acid levels identify a subgroup more prone to in-ICCU complications, probably because hyperuricemia stems from several complex mechanisms ranging from pre-existing risk factors to the degree of myocardial ischemia (as indicated by Killip class, ejection fraction) and to the acute metabolic response (as inferred by glucose levels). Hyperuricemia is not independently associated with early mortality when adjusted for renal function and the degree of myocardial damage.