Gender-Related Association of Serum Uric Acid and Left Ventricular Hypertrophy in Hypertension

Association between serum uric acid levels and left ventricular hypertrophy based on electrocardiographic findings: a sex-specific analysis across cardiometabolic diseases

The association between serum uric acid (UA) levels and left ventricular hypertrophy (LVH) remains unclear. We aimed to investigate this association using electrocardiographic findings. Health examination data from Kagoshima Kouseiren Hospital included 79,200 participants without cardiovascular diseases. Hypertension was defined as a blood pressure ≥ 140/90 mmHg. A Sokolow-Lyon criterion of ≥ 3.5 mm was used to define LVH. Sex-specific associations between UA and LVH were adjusted for age, body mass index, systolic blood pressure, serum triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting plasma glucose, estimated glomerular filtration rate, and lifestyle factors. The mean UA levels were 4.5 ± 1.1 and 6.1 ± 1.4 mg/dL in women and men, respectively (LVH prevalences, 4.0%, and 11.8%, respectively). Individuals without and with hypertension had mean UA levels of 5.2 ± 1.4 and 5.7 ± 1.5 mg/dL, respectively (LVH prevalences, 5.5%, and 14.4%, respectively). UA levels were significantly associated with LVH in women aged 40-49 and 50-59 years and in men aged 50-59 years. Compared with the first UA quartile, the fourth quartile showed a more significant association with LVH in individuals without hypertension. Furthermore, UA was associated with LVH in individuals without obesity, dyslipidemia, reduced kidney function, and diabetes in both sexes. Serum UA levels are associated with LVH in middle-aged women and men without cardiovascular disease risk, suggesting the potential role of UA as an LVH marker. Anwar Ahmed Salim and Shin Kawasoe contributed equally to this work.

Association of serum uric acid with right cardiac chamber remodeling assessed by cardiovascular magnetic resonance feature tracking in patients with connective tissue disease

Background

Right cardiac chamber remodeling is widespread in patients with connective tissue disease (CTD). Serum uric acid (SUA) is considered a potential independent risk factor for cardiovascular disease, and elevated SUA levels are often observed in patients with CTD. The correlation between SUA levels and right cardiac chamber remodeling remains unclear. This study investigated the association of SUA with right cardiac chamber remodeling as assessed by cardiac magnetic resonance feature-tracking (CMR-FT) in CTD patients.

Methods and results

In this cross-sectional study, a total of 104 CTD patients and 52 age- and sex-matched controls were consecutively recruited. All individuals underwent CMR imaging, and their SUA levels were recorded. The patients were divided into three subgroups based on the tertiles of SUA level in the present study. CMR-FT was used to evaluate the right atrial (RA) longitudinal strain and strain rate parameters as well as right ventricular (RV) global systolic peak strain and strain rate in longitudinal and circumferential directions for each subject. Univariable and multivariable linear regression analyses were used to explore the association of SUA with RV and RA strain parameters. Compared with the controls, the CTD patients showed significantly higher SUA levels but a lower RV global circumferential strain (GCS) and RA phasic strain parameters (all p < 0.05), except the RA booster strain rate. RV GCS remained impaired even in CTD patients with preserved RV ejection fraction. Among subgroups, the patients in the third tertile had significantly impaired RV longitudinal strain (GLS), RV GCS, and RA reservoir and conduit strain compared with those in the first tertile (all p < 0.05). The SUA levels were negatively correlated with RV GLS and RV GCS as well as with RA reservoir and conduit strain and strain rates (the absolute values of β were 0.250 to 0.293, all P < 0.05). In the multivariable linear regression analysis, the SUA level was still an independent determinant of RA conduit strain (β = -0.212, P = 0.035) and RV GCS (β = 0.207, P = 0.019).

Conclusion

SUA may be a potential risk factor of right cardiac chamber remodeling and is independently associated with impaired RA conduit strain and RV GCS in CTD patients.

Serum uric acid and left ventricular mass index independently predict cardiovascular mortality: The uric acid right for heart health (URRAH) project

A relationship between serum uric acid (SUA) and cardiovascular (CV) events has been documented in the Uric Acid Right for Heart Health (URRAH) study.

AIM

of this study was to investigate the association between SUA and left ventricular mass index (LVMI) and whether SUA and LVMI or their combination may predict the incidence of CV death.

METHODS

Subjects with echocardiographic measurement of LVMI included in the URRAH study (n=10733) were part of this analysis. LV hypertrophy (LVH) was defined as LVMI > 95 g/m2 in women and 115 g/m2 in men.

RESULTS

A significant association between SUA and LVMI was observed in multiple regression analysis in men: beta 0,095, F 5.47, P< 0.001 and women: beta 0,069, F 4.36, P<0.001. During follow-up 319 CV deaths occurred. Kaplan-Meier curves showed a significantly poorer survival rate in subjects with higher SUA (> 5.6 mg/dl in men and 5.1 mg/dl in women) and LVH (log-rank chi-square 298.105; P<0.0001). At multivariate Cox regression analysis in women LVH alone and the combination of higher SUA and LVH but not hyperuricemia alone, were associated with a higher risk of CV death, while in men hyperuricemia without LVH, LVH without hyperuricemia and their combination were all associated with a higher incidence of CV death.

CONCLUSIONS

Our findings demonstrate that SUA is independently associated with LVMI and suggest that the combination of hyperuricemia with LVH is an independent and powerful predictor for CV death both in men and women.

Hyperuricemia Is Associated With the Risk of Atrial Fibrillation Independent of Sex: A Dose-Response Meta-Analysis

Background:

Conflicting findings of the association between serum uric acid (SUA) and atrial fibrillation (AF) have been reported in both men and women. The sex-specific associations between SUA and the risk of AF are unclear, although hyperuricemia is independently associated with the risk of AF. We performed this meta-analysis to assess the sex-specific effect of SUA on the risk of AF.

Methods

The PubMed, EMBASE, and Cochrane Library databases were searched up to October 3, 2021, for studies that reported sex-specific associations of SUA levels with AF. Linear relationships were assessed by the generalized least squares trend estimation. This study was registered with PROSPERO (42020193013).

Results

Ten eligible studies with 814,804 participants (415,779 men and 399,025 women) were identified. In the category analysis, high SUA was associated with an increased risk of AF in both men (OR: 1.42; 95% CI, 1.18–1.71, I² = 34%) and women (OR: 2.02; 95% CI, 1.29–3.16, I² = 70%). In the dose-response analysis, for each 60 μmol/L (1 mg/dL) increase in the SUA level, the risk of AF increased by 15% (OR: 1.15; 95% CI, 1.07–1.25, I² = 74%) in men and 35% (OR: 1.35; 95% CI, 1.18–1.53, I² = 73%) in women. There was a borderline difference in the impact of SUA on the risk of AF between men and women (P for interaction = 0.05). A significant linear relationship between SUA and the risk of AF was observed in men (P for non-linearity = 0.91) and women (P for non-linearity = 0.92).

Conclusions

This study suggested that there was a significant linear relationship between SUA and the risk of AF among men and women, with a higher risk estimate for women. Additional trials are required to assess the effect of reduced SUA therapy on AF incidence.

Systematic Review Registration

https:www.crd.york.ac.uk/PROSPERO/, identifier: CRD 42020193013.

U-Shaped Association between Sleep Duration, C-Reactive Protein, and Uric Acid in Korean Women

Serum high-sensitivity C-reactive protein (hsCRP) and serum uric acid (SUA) are biomarkers that predict chronic inflammation and cardiovascular dysfunction. Therefore, we aimed to investigate the association between sleep duration, hsCRP, and SUA in Korean women. Cross-sectional data from the Seventh Korea National Health and Nutrition Examination Survey was analyzed. The odds ratio (OR) and 95% confidence intervals (CIs) for an association between higher hsCRP (>2.0 mg/L) or higher SUA (>5.6 mg/dL) and sleep duration were calculated using multiple logistic regression analyses after adjusting for potential confounders. In total, 6151 women were included in the analysis. There was a U-shaped relationship between continuous sleep duration, hsCRP, and SUA. Compared to those who slept for 7-8 h, the ORs (95% CIs) for higher hsCRP were 1.43 (0.95-2.16) in short sleepers and 1.64 (1.09-2.48) in long sleepers after adjusting for confounders. Compared with those who slept for 7-8 h, the ORs (95% CIs) for higher SUA were 1.54 (1.04-2.26) in short sleepers and 1.94 (1.27-2.96) in long sleepers after adjusting for confounders. We found a U-shaped association between sleep duration, hsCRP, and SUA in Korean women. 7-8 h sleep was associated with lower level of hsCRP and SUA in Korean women.

Effect of Long-Term Allopurinol Therapy on Left Ventricular Mass Index in Patients with Ischemic Heart Disease; A Cross-Sectional Study

Background

Left ventricular hypertrophy (LVH), as assessed by measurement of left ventricular mass (LVM), is one of the most important cardiovascular risk factors. It is commonly present in patients with ischemic heart disease (IHD), irrespective of the level of blood pressure; recently, oxidative stress has been shown to be an important factor in its development. The question then arises: can this risk factor be modified by antioxidant treatment (e.g., with allopurinol, a xanthine oxidase inhibitor)?

Methods

This is an observational study with a cross-sectional design which explored the association between long-term (>12 months) allopurinol therapy and LV mass index (LVMI) as well as geometry in patients generally receiving standard treatments for IHD. The primary endpoint was LVMI measurement (by 2D-echocardiography) and secondary endpoints included the association of allopurinol use with LV function (ejection fraction), blood pressure, glycemic control, and lipid profile.

Results

Ninety-six patients on standard anti-ischemic drug treatment (control group) and 96 patients who were additionally taking allopurinol (minimum dose 100 mg/day) were enrolled. Both groups were matched for age, sex, height, and co-morbidities, but poorer kidney function in the allopurinol group required further sub-group analysis based on renal function. Allopurinol treatment was associated with the lowest LVMI in the patients with normal serum creatinine (median LVMI; 70.5 g/m²): corresponding values were 76.0 and 87.0 in the control group with, respectively, normal and elevated serum creatinine, and 89.5 in the allopurinol group with elevated serum creatinine (P=0.027). In addition, allopurinol was associated with better glycemic control (HbA1c) with a difference of 0.8% (95% CI; 1.3, 0.2) (P=0.004) as compared with control patients.

Conclusion

In our population, treatment with allopurinol (presumably because of its anti-oxidant properties) has shown a tendency to be associated with smaller LVM in IHD patients with normal serum creatinine, along with better glycemic control.

Impact of serum uric acid on incident hypertension in a worksite population of Japanese men

OBJECTIVE

Higher levels of serum uric acid are associated with an increased risk of cardiovascular diseases, which may be confounded by comorbidities. We investigated the effects of serum uric acid on the risk of hypertension in Japanese men at a worksite.

METHODS

We evaluated a total of 2335 Japanese male workers without hypertension who ranged in age from 18 to 64 years at a worksite in 2009. These men were followed for 6 years from 2009 to 2015.

RESULTS

During the follow-up period, 380 individuals developed hypertension. The odds ratio for the incident hypertension was estimated according to quartiles of serum uric acid levels of 5.1 or less, 5.2-5.8, 5.9-6.6, and at least 6.7 mg/dl. The multivariable-adjusted risk of incident hypertension was significantly higher in the highest serum uric acid quartile than in the lowest: odds ratio 1.00 (reference) for the lowest quartile, 1.34 (0.91-1.97) for the second quartile, 1.42 (0.97-2.06) for the third quartile, and 1.65 (1.14-2.40) for the highest quartile. In stratified analyses, the association between serum uric acid and incident hypertension was significant in the patients of aged below 45 years and without comorbidities, namely diabetes and low levels of high-density lipoprotein-cholesterol.

CONCLUSIONS

Serum uric acid levels were associated with the future incidence of hypertension, and the association was observed in the younger individuals, those without diabetes, and those with preserved high-density lipoprotein cholesterol levels in a worksite population of Japanese men.

Association between serum uric acid level and hypertension in a Chinese elderly rural population

Previous studies have examined the association between elevated serum uric acid (SUA) level and hypertension; however, the association in the Chinese elderly is still uncertain. A cross-sectional study was performed in a rural district of Beijing. A total of 2,397 participants (967 men and 1,430 women) completed the survey. The SUA levels of participants were categorized into four levels using the quartiles (P25, P50, and P75) as cutoff values. Participant was diagnosed as hyperuricemia if the SUA level was ≥417 μmol/L (male) or ≥357 μmol/L (female). Hypertension was defined as systolic blood pressure (BP) ≥140 mmHg and/or diastolic BP ≥90 mmHg and/or receiving antihypertensive drug treatment. Multiple logistic regression was used to estimate the association between SUA and hypertension. We found that higher SUA level was associated with the increased risk of hypertension in both sexes, even after adjusting for potential confounding variables. In total, the risk for having hypertension increased by 0.3% per 1 μmol/L increment in SUA level, increased by 95% for the highest vs. lowest quartile of SUA level, and increased by 111% in the hyperuricemia patients. Moreover, we found that the association was more pronounced in the male participants. There were approximately J-shaped relationships between SUA level (quartiles) and hypertension in all age groups. Higher SUA levels are positively associated with hypertension among the Chinese rural elderly. Further studies are still required to determine the relationship between SUA level and hypertension and to explore its potential biological mechanisms underlying the gender-related association in the elderly population.

ABBREVIATIONS

CVD; cardiovascular disease; BMI: body mass index; BP: blood pressure; SUA: serum uric acid; TC: total cholesterol; TG: triglycerides; HDL-C: high-density lipoprotein; LDL-C: low-density lipoprotein; FPG: fasting blood glucose; OR: odds ratio; CI: confidence interval; SD: standard deviation.

Is Serum Uric Acid Independently Associated With Left Ventricular Mass Index, Ejection Fraction, and B-Type Natriuretic Peptide Among Female and Male Cardiac Patients?

Mean serum uric acid (SUA) levels are higher in men than women. In addition, recent studies have suggested that the SUA threshold at which the cardiovascular risk might increase may vary between women and men. In the current retrospective study, by analyzing the data from 219 female and 519 male patients who were free from uric acid-lowering medication, we investigated whether SUA is associated with left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF), and plasma levels of B-type natriuretic peptide (BNP) independent of confounding factors, such as serum calcium, inorganic phosphate, and fibroblast growth factor 23 (FGF23), in a gender-specific manner.In multivariate stepwise linear regression analysis in which age, blood pressure, eGFR, corrected calcium, inorganic phosphate, and FGF23 were entered as potential covariates, SUA was selected as a factor significantly associated with LVEF, LVMI, and plasma levels of BNP in both genders. On the other hand, however, after adding diuretic use as a potential covariate, the association between SUA and LVEF lost statistical significance in both genders, and that between SUA and BNP lost significance among female patients. These findings suggest that diuretic use is a non-negligible confounder in understanding the observed association between SUA and cardiac dysfunction and heart failure.In summary, SUA is associated with left ventricular hypertrophy independent of confounding factors including FGF23 and diuretic use in female and male patients. Whether lowering SUA can influence the progression of cardiac remodeling awaits further investigation.

Uric Acid and New Onset Left Ventricular Hypertrophy: Findings From the PAMELA Population

BACKGROUND

The association between serum uric acid (SUA) and left ventricular hypertrophy (LVH) is controversial and the ability of SUA in predicting incident LVH remains unsettled. Thus, we evaluated the relationship of SUA with new-onset echocardiographic LVH over a 10-year period in subjects of the general population enrolled in the Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study.

METHODS

The study included 960 subjects with normal LV mass index (LVMI) at baseline echocardiographic evaluation and a readable echocardiogram at the end of follow-up. Cut-points for LVH were derived from reference values of the healthy fraction of the PAMELA population.

RESULTS

Over a 10-year period, 258 participants (26.9%) progressed to LVH. The incidence of new-onset LVH increased from the lowest (23%) to intermediate (25%) and the highest baseline SUA tertile (32%). After adjusting for confounders (not including body mass index (BMI)), each 1 mg/dl increase in SUA entailed a 26% higher risk of incident LVH. Adjusted odd ratio of LVH risk in the highest SUA tertile was 96% higher than in the lowest tertile (odds ratio (OR) = 1.966, 95% CI = 1.158-3.339, P = 0.0123). Correction for BMI reduced the magnitude and statistical significance of ORs.

CONCLUSIONS

The study shows that SUA is a predictor of long-term echocardiographic changes from normal LVMI to LVH in a community sample. Thus, life-style and pharmacologic measures aimed to reduce SUA levels may concur to preventing LVH development in the general population.

Increased Serum Uric Acid Level Is a Risk Factor for Left Ventricular Hypertrophy but Not Independent of eGFR in Patients with Type 2 Diabetic Kidney Disease

BACKGROUND

Although the relation between serum uric acid (SUA) and left ventricular hypertrophy (LVH) has been studied for decades, however, their association remains debatable.

METHODS

This is a retrospective study in which a total of 435 hospitalized Chinese patients with type 2 DKD were enrolled. The subjects were stratified into quartiles according to SUA level. LVH was assessed by two-dimensional guided M-mode echocardiography.

RESULTS

There was a significant increase in the prevalence of LVH in patients with type 2 DKD across SUA quartiles (28.9, 26.5, 36.1, and 49.5%; p < 0.001). The Spearman analysis indicated that SUA was positively correlated to LVMI and negatively correlated to eGFR. The logistic regression analysis revealed that the odd ratio for LVH in the highest SUA quartile was 2.439 (95% CI 1.265-4.699; p = 0.008; model 1) or 2.576 (95% CI 1.150-5.768; p = 0.021; model 2) compared with that in the lowest SUA quartile. However, there was no significant increased risk of LVH in the subjects with the highest SUA quartile after adjusting the eGFR (OR = 1.750; 95% CI 0.685-4.470; p = 0.242; model 3).

CONCLUSIONS

In selected population, such as type 2 DKD, the elevated SUA level is positively linked with the increased risk of LVH, but this relationship is not independent of eGFR.

Gender-related differences in the association between serum uric acid and left ventricular mass index in patients with obstructive hypertrophic cardiomyopathy

BACKGROUND

Serum uric acid (SUA) is associated with left ventricular hypertrophy in a wide spectrum of study population. However, whether this association exists in patients with hypertrophic cardiomyopathy (HCM, including obstructive HCM), and if present, whether gender has any impact on this association, remains unknown.

METHODS

A total of 161 patients with obstructive HCM (age 47.2 ± 10.8 years, 99 (62 %) men) were included in this study. All patients underwent extensive clinical, laboratory, echocardiographic, and cardiac magnetic resonance (CMR) imaging examinations. Left ventricular mass index (LVMI) was assessed using CMR.

RESULTS

The mean value of SUA was 353.4 ± 87.5 μmol/L. Both SUA levels (381.2 ± 86.4 vs. 309.0 ± 69.3 μmol/L, p < 0.001) and LVMI (96.2 ± 32.1 vs. 84.4 ± 32.4 g/m(2), p = 0.025) were significantly higher in men than in women. LVMI increased progressively across sex-specific tertiles of SUA in women (p = 0.030), but not in men (p = 0.177). SUA was positively correlated with LVMI in female patients (r = 0.372, p = 0.003), but not in males (r = 0.112, p = 0.269). On multivariate linear regression analysis, SUA was independently associated with LVMI in females (β = 0.375, p = 0.002), but not in males.

CONCLUSIONS

SUA levels are significantly and independently associated with LVMI in women with obstructive HCM, but not in men. Our findings imply the potential significance of urate-lowering regimens in female patients with obstructive HCM.

Uric Acid and Cardiovascular Disease: An Update

In recent years, serum uric acid (SUA) as a determinant of cardiovascular (CV) risk has gained interest. Epidemiological, experimental and clinical data show that patients with hyperuricaemia SUA are at increased risk of cardiac, renal and vascular damage and CV events. There is now some evidence to suggest that urate-lowering treatment may reduce CV risk in this group and, thus, may represent a new strategy in risk reduction.

Combination of hyperuricemia and metabolic syndrome is an independent and powerful predictor for left ventricular hypertrophy in rural Chinese

OBJECTIVES

To investigate the influence of MetS (metabolic syndrome) in combination with hyperuricemia on left ventricular hypertrophy (LVH) in residents in the rural area of Northeast China.

METHODS

We performed a cross-sectional baseline data analysis of 11,170 subjects (mean age: 54±11years) recruited from the rural area of China. Anthropometric indicators were measured according to standard methods. MetS was defined by the ATP III modified criteria. Hyperuricemia was defined according to sex-specific serum uric acid levels (SUA): SUA≥7.0mg/dL for male and≥6.0mg/dL for female. Four groups were listed: normouricemia non-MetS, hyperuricemia non-MetS, MetS normouricemia and hyperuricemia MetS.

RESULTS

Left ventricular mass index for height(2.7) (LVMH(2.7)) in female was significantly higher in hyperuricemia MetS group than that in normouricemia non-MetS (52.43±16.60 vs. 40.04±10.72g/m(2.7), P<0.001) group. Similar result was observed in men (48.93±13.17g/m(2.7) vs. 43.63±11.90g/m(2.7), P<0.001). The result of multiple regression analysis indicated that hyperuricemia MetS group had higher risk of LVH than other three groups (OR: 3.427 for female, P<0.001, OR: 1.987 for male, P<0.001). Moreover, female subjects in MetS normouricemia group [OR (95% CI): 2.313 (1.991-2.686)] had greater risk of LVH than that in hyperuricemia non-MetS group [OR (95% CI): 1.917 (1.166-3.151)]. Hyperuricemia non-MetS was found to be significantly and independently associated with LVH in women, but not in men.

CONCLUSION

Our study finds that the combination of hyperuricemia and MetS are independent and powerful predictor for LVH in rural area of Northeast Chinese. Women with MetS in combination with hyperuricemia have higher risk of LVH than men. It seems that MetS has greater effect on LVH than hyperuricemia does in women but not in men.

Hyperuricemia is independently associated with left ventricular hypertrophy in post-menopausal women but not in pre-menopausal women in rural Northeast China

The aim of this article is to estimate the relationship between hyperuricemia and left ventricular hypertrophy (LVH) and to investigate whether menopause was associated with the relationship between hyperuricemia and LVH. This survey was conducted from July 2012 to August 2013. A total of 6029 women (3508, 58.2% were post-menopause) from the rural Northeast China were randomly selected and examined. LVH was defined using the 2007 Guidelines for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Age, body mass index, glucose, estimated glomerular filtration rate and lipid level were significantly correlated with serum uric acid level. LVH showed a gradual increase in accordance with the serum uric acid level in entire study population (<4.0 mg/dL, 11.4%; 4 to <5 mg/dL, 14.9%; 5 to <6 mg/dL, 18.9%; ≥6 mg/dL, 27.4%; p < 0.001). Multivariate analysis revealed that hyperuricemia was a significantly independent risk factor for LVH in post-menopausal women [OR (95% CI): 1.367 (1.026, 1.821)], but not in pre-menopausal women [OR (95% CI): 1.290 (0.669, 2.486)]. These findings suggested that hyperuricemia can be used as a risk marker of LVH in a female population and, in particular, as an independent risk factor in post-menopausal women but not in pre-menopausal women.

Uricaemia and left ventricular mass in hypertensive patients

BACKGROUND

Both hyperuricaemia and left ventricular (LV) hypertrophy are associated with the metabolic syndrome and increased cardiovascular risk. The relationship between uric acid levels and left ventricular mass in hypertension, however, is unclear. In this study, we have investigated this relationship in hypertensive patients without the metabolic syndrome.

MATERIALS AND METHODS

In a cross-sectional study, 367 nondiabetic, essential hypertensive patients (age 52 ± 14; 194 males and 173 females) free of clinically relevant cardiovascular complications and without the metabolic syndrome were consecutively recruited at a university hypertension clinic. In these patients, we measured plasma levels of uric acid, lipids, glucose and insulin at fast and after an oral glucose load (OGTT), renal function and performed both conventional and tissue Doppler echocardiography.

RESULTS

Hypertensive patients with LV hypertrophy had higher uric acid levels and greater prevalence of hyperuricemia than patients with normal left ventricular mass. Uric acid levels were directly related with fasting and post-OGTT plasma insulin and with the HOMA index and inversely with 24-h creatinine clearance. Uric acid was also significantly and directly related with the left ventricular mass and multivariate regression analysis showed that this relationship was independent from components of the metabolic syndrome and renal function in women, but not in men.

CONCLUSIONS

Elevated uric acid levels are independently related to the left ventricular mass in hypertensive women without the metabolic syndrome. In these patients with a low cardiovascular risk profile, uric acid might contribute to the development of subclinical cardiac damage.

Effect of losartan on serum uric acid in hypertension treated with a diuretic: the COMFORT study

It has been shown that losartan, an angiotensin II receptor blocker (ARB), reduces serum uric acid levels. However, the effects of losartan on serum uric acid levels in the patients treated with a thiazide diuretic have not been fully elucidated. We have investigated the effects of losartan compared with other ARBs on blood variables and blood pressure control in hypertensive patients treated with a thiazide diuretic using data from the COMFORT study. The present analysis included a total of 118 hypertensive subjects on combination treatment with ARBs except for losartan and a diuretic who were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or to continuation of two pills, an ARB except for losartan and a diuretic. Blood pressures were evaluated at 1, 3, and 6 months after randomization and changes in blood variables including serum uric acid were evaluated during 6 months treatment period. Mean follow-up blood pressure levels were not different between the combination pill (losartan treatment) group and the control (ARBs except for losartan) group. On the other hand, serum uric acid significantly decreased in the combination pill group compared with the control group (-0.44 versus + 0.10 mg/dl; p = 0.01), although hematocrit, serum creatinine, sodium and potassium were not different between the groups. These results suggest that the treatment regimen switched from a combination therapy of ARBs except for losartan and a diuretic to a combination pill (losartan/ hydrochlorothiazide) decreases serum uric acid without affecting blood pressure control.

Serum uric acid and target organ damage in essential hypertension

Background

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

Objective

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

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

Results

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

Conclusion

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

Serum uric acid levels in patients with Alzheimer's disease: a meta-analysis

Background

Serum uric acid (UA) could exert neuro-protective effects against Alzheimer's disease (AD) via its antioxidant capacities. Many studies investigated serum UA levels in AD patients, but to date, results from these observational studies are conflicting.

Methods

We conducted a meta-analysis to compare serum UA levels between AD patients and healthy controls by the random-effects model. Studies were identified by searching PubMed, ISI Web of Science, EMBASE, and the Cochrane library databases from 1966 through July 2013 using the Medical Subject Headings and keywords without restriction in languages. Only case-control studies were included if they had data on serum UA levels in AD patients and healthy controls. Begg's funnel plot and Egger's regression test were applied to assess the potential publication bias. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity.

Results

A total of 11 studies met the inclusion criteria including 2708 participants were abstracted. Serum UA levels were not significantly different in AD patients compared to healthy controls (standardized mean difference (SMD) = −0.50; 95% confidence interval (CI): −1.23 to 0.22). Little evidence of publication bias was observed. Sensitivity analyses showed that the combined SMD was consistent every time omitting any one study, except only one study which greatly influenced the overall results. Meta-regression showed that year of publication, race, sample size, and mean age were not significant sources of heterogeneity.

Conclusion

Our meta-analysis of case-control studies suggests that serum UA levels do not differ significantly in AD patients, but there may be a trend toward decreased UA in AD after an appropriate interpretation. More well-designed investigations are needed to demonstrate the potential change of serum UA levels in AD patients.

Serum uric acid is associated with the left ventricular mass index in males of a general population

The association of serum uric acid (UA) with left ventricular hypertrophy (LVH) remains controversial. We investigated this issue in a general population. Participants consisted of 1,943 subjects (774 males and 1,169 females) aged over 40 years, living in Tanushimaru (a Japanese cohort of the Seven Countries Study). Serum UA and other biochemistry parameters were determined by a standard analytical technique. All individuals underwent anthropometric measurements and 2-dimensional echocardiography. Because serum UA levels are much higher in males than in females, they were analyzed separately. When LV mass index (LVMI) levels were stratified according to tertile as low (≤ 80 cm(2): n = 261), middle (81-103 cm(2): n = 261), and high (≥ 104 cm(2): n = 252) in males, there were significant relationships between LVMI and UA, in addition to age, body mass index, systolic blood pressure, medication for hypertension, triglycerides, and alcohol intake. Multiple stepwise regression analysis revealed LVMI was significantly associated with systolic BP (P < 0.0001), medication for hypertension (P < 0.0001), UA (P = 0.003), BMI (P = 0.019), and alcohol intake (P = 0.038) in males. In females, LVMI was not associated with UA. In a multiple logistic regression analysis, a significantly higher odds ratio of LVH (odds ratio: 1.77, 95%CI: 1.01-3.09, P < 0.05) was observed for males in the highest UA tertile versus the lowest UA tertile after adjustments for confounding factors, but not for females. In this cross-sectional study, there was a clear difference in the relation of UA and LVH between males and females. High serum UA was significantly and independently associated with LVH evaluated by echocardiography in only males of a general population.

Serum uric acid is associated with left ventricular hypertrophy independent of serum parathyroid hormone in male cardiac patients

Background

Several studies have shown that serum uric acid (UA) is associated with left ventricular (LV) hypertrophy. Serum levels of parathyroid hormone (PTH), which has bbe shown to be correlated with UA, is also known to be associated with cardiac hypertrophy; however, whether the association between UA and cardiac hypertrophy is independent of PTH remains unknown.

Purpose

We investigated whether the relationship between serum uric acid (UA) and LV hypertrophy is independent of intact PTH and other calcium-phosphate metabolism-related factors in cardiac patients.

Methods and Results

In a retrospective study, the association between UA and left ventricular mass index was assessed among 116 male cardiac patients (mean age 65±12 years) who were not taking UA lowering drugs. The median UA value was 5.9 mg/dL. Neither age nor body mass index differed significantly among the UA quartile groups. Patients with higher UA levels were more likely to be taking loop diuretics. UA showed a significant correlation with intact PTH (R = 0.34, P<0.001) but not with other calcium-phosphate metabolism-related factors. Linear regression analysis showed that log-transformed UA showed a significant association with left ventricular mass index, and this relationship was found to be significant exclusively in patients who were not taking loop and/or thiazide diuretics. Multivariate logistic regression analysis showed that log-transformed UA was independently associated with LV hypertrophy with an odds ratio of 2.79 (95% confidence interval 1.48–5.28, P = 0.002 per one standard deviation increase).

Conclusions

Among cardiac patients, serum UA was associated with LV hypertrophy, and this relationship was, at least in part, independent of intact PTH levels, which showed a significant correlation with UA in the same population.

A gender-specific analysis of association between hyperuricaemia and cardiovascular events in patients with coronary artery disease

BACKGROUND AND AIMS

Gender-related differences in the association between hyperuricaemia and cardiovascular events remain poorly understood. The objective of this study was to assess gender-related differences in the association between hyperuricaemia and cardiovascular events in patients with coronary artery disease (CAD).

METHODS AND RESULTS

This study included 13,273 patients with CAD. Hyperuricaemia was defined as a plasma uric acid >7.0mgdl(-1) in men and >5.7mgdl(-1) in women. The primary outcome was 1-year all-cause mortality. Hyperuricaemia was found in 3745 men (36.5%) and 1562 women (50.3%); odds ratio (OR)=1.76, 95% confidence interval (CI) 1.62-1.91; P<0.001. Women with hyperuricaemia were older, had higher proportions of patients with diabetes and arterial hypertension and had reduced renal function and higher C-reactive protein levels compared with men with hyperuricaemia. One-year all-cause mortality was 9.3% (n=143) in women with hyperuricaemia versus 6.9% (n = 252) in men with hyperuricaemia (P=0.002). After adjustment in multivariable Cox proportional hazards model, uric acid predicted 1-year mortality with an adjusted hazard ratio (HR)=1.17, 95% CI (1.03-1.31), P=0.012 in men and HR=1.25, 95% CI (1.06-1.48), P=0.007 in women, for each standard deviation increase in the natural logarithm. Uric acid predicted 1-year mortality with an area under the receiver-operating characteristic curve=0.625, 95% CI (0.594-0.656) in men and 0.676, 95% CI (0.635-0.717) in women (P=0.044, for women versus men).

CONCLUSION

Hyperuricaemia predicts an increased risk of 1-year mortality in both genders with a stronger association in women. Differences in cardiovascular risk profile may explain the stronger association between hyperuricaemia and cardiovascular events in women.

Sex differences in the association between serum uric acid levels and cardiac hypertrophy in patients with chronic kidney disease

Several studies have documented an association between serum uric acid (SUA) concentration and cardiac hypertrophy in hypertensive patients; however, the association remains unclear in chronic kidney disease (CKD) patients. If there is an association between SUA and hypertrophy in these patients, it is unknown whether the association is different between men and women. Our aim in this study is to determine whether SUA is associated with cardiac hypertrophy in CKD patients, focusing on any sex differences. Two hundred sixteen CKD patients (117 men and 99 women) were enrolled in this cross-sectional study. Patients prescribed uric acid-lowering agents and those with congestive heart failure, valvular heart disease, or ischemic heart disease were excluded from this study. Left ventricular mass index (LVMI) and left ventricular hypertrophy (LVH) were assessed using echocardiography. The prevalence of LVH was 58% in men and 47% in women. In multivariate linear regression analysis, SUA levels did not correlate with LVMI in men, whereas SUA was independently associated with LVMI in women (β=0.27, P=0.02). Multivariate logistic regression analysis also revealed that diabetes mellitus (odds ratio (OR), 4.41; P=0.01) was associated with LVH in men, whereas age (OR, 1.13; P<0.01), hypertension (OR, 7.38; P=0.03) and SUA (OR, 1.91; P=0.03) were associated with LVH in women. In female CKD patients, SUA levels were associated with LVMI and LVH, whereas there was no association in male patients. These observations suggest that an association between SUA levels and the development of cardiac hypertrophy is more likely in women than in men.

Absence of an independent association between serum uric acid and left ventricular mass in Caucasian hypertensive women and men

BACKGROUND AND AIM

Experimentally uric acid may induce cardiomyocyte growth and interstitial fibrosis of the heart. However, clinical studies exploring the relationship between serum uric acid (SUA) and left ventricular (LV) mass yielded conflicting results. The aim of our study was to evaluate the relationships between SUA and LV mass in a large group of Caucasian essential hypertensive subjects.

METHODS AND RESULTS

We enrolled 534 hypertensive patients free of cardiovascular complications and without severe renal insufficiency. In all subjects routine blood chemistry, including SUA determination, echocardiographic examination and 24 h ambulatory blood pressure (BP) monitoring were obtained. In the overall population we observed no significant correlation of SUA with LV mass indexed for height(2.7) (LVMH(2.7)) (r = 0.074). When the same relationship was analysed separately in men and women, we found a statistically significant correlation in female gender (r = 0.27; p < 0.001), but not in males (r = -0.042; p = NS). When we grouped the study population in sex-specific tertiles of SUA, an increase in LVMH(2.7) was observed in the highest tertiles in women (44.5 ± 15.6 vs 47.5 ± 16 vs 55.9 ± 22.2 g/m(2.7); p < 0.001), but not in men. The association between SUA and LVMH(2.7) in women lost statistical significance in multiple regression analyses, after adjustment for age, 24 h systolic BP, body mass index, serum creatinine and other potential confounders.

CONCLUSIONS

Our findings do not support an independent association between SUA and LV mass in Caucasian men and women with arterial hypertension.

Association among serum uric acid, cardiovascular risk, and arterial stiffness: a cross-sectional study in She ethnic minority group of Fujian Province in China

OBJECTIVES

To investigate the association between serum uric acid levels, cardiovascular risk, and arterial stiffness in She ethnic minority in South China's Fujian Province.

METHODS

5109 participants aged 20-79 yr were enrolled in analysis. Tpeak-Tend interval (Tp-e), QT interval, and height of the R wave in lead aVL (aVLR) were measured on 12-lead electrocardiogram (ECG), and Minnesota code-indicated major abnormal ECG MA-ECG was used as a risk indicator of cardiovascular disease. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV).

RESULTS

Longer Tp-e interval, greater Tp-e/QT ratio, and higher aVLR were observed in the highest quartile of uric acid level. The incidence of MA-ECG was gradually increased from lowest to highest quartile of serum uric acid in males (p for trend <0.01). After adjusting traditional cardiovascular risk factors, multivariate analysis revealed that the fourth quartile of serum uric acid level was independently associated with MA-ECG in males [odds ratios (OR) (95% confidence interval): 2.129 (1.376-3.295)] but not in females. Serum uric acid was also associated with abnormal baPWV, when adjusted for atherogenic confounders. Compared with the lowest serum uric acid quartile, the OR (95% confidence interval) of the second, third, and fourth quartile were 1.920 (1.246-2.957), 1.650 (1.064-2.558), and 2.501 (1.600-3.908) in males.

CONCLUSION

Among China's She ethnic minority, uric acid level was independently related to arterial stiffness assessed by baPWV in both genders. The evaluation of uric acid level was related to higher cardiovascular risk in males but not in females.

Sex/gender medicine. The biological basis for personalized care in cardiovascular medicine

Sex differences in morbidity and mortality associated with cardiovascular disease have been recognized by the medical community for decades. Investigation into the underlying biological basis of these differences was largely neglected by the scientific community until a report released by the Institute of Medicine in the United States in 2001 "Exploring the Biological Contributions to Human Health: Does Sex Matter?" Recommendations from this report included the need for more accurate use of the terms "sex" and "gender", better tools and resources to study the biological basis of sex differences, integration of findings from different levels of biological organization and continued synergy between basic and clinical researchers. Ten years after the Institute's report, this review evaluates some of the sex differences in cardiovascular disease, reviews new approaches to study sex differences and emphasizes areas where further research is required. In the era of personalized medicine, the study of the biological basis of sex differences promises to optimize preventive, diagnostic and therapeutic strategies for cardiovascular disease in men and women, but will require diligence by the scientific and medical communities to remember that sex does matter.

Uric acid as a marker for renal dysfunction in hypertensive women on diuretic and nondiuretic therapy

Hyperuricemia is a common finding in hypertensive patients, especially among those who are on diuretic therapy. However, its clinical relevance regarding cardiovascular and chronic kidney disease (CKD) has not clearly been established. The authors assessed whether, in a population of 385 hypertensive women categorized according to diuretic therapy, the stratification in quartiles by uric acid levels would identify a gradient of changes in renal function and in risk factors for cardiovascular disease. The following were evaluated: serum uric acid, glycemia, total and fractional cholesterol, triglycerides, apolipoprotein (Apo) B, Apo A-I, and C-reactive protein. Renal function was assessed by serum creatinine, albuminuria, and estimated glomerular filtration rate (eGFR) by the Modification of Diet in Renal Disease equation, whereas cardiovascular risk was estimated through the Framingham score. A total of 246 women were on diuretic therapy; 139 were taking other antihypertensive medications. There was a reduction in eGFR parallel to the increase in uric acid levels, regardless of diuretic use and without a concomitant increase in albuminuria. In both groups, higher uric acid levels translated into an increase in metabolic syndrome components, in markers of insulin resistance, triglyceride / high-density lipoprotein levels, and Apo B/Apo A-I ratios, as well as in Framingham scores. Hyperuricemia was associated with an increase in inflammatory markers only in patients on diuretic therapy. In a binary logistic regression, hyperuricemia (uric acid >6.0 mg/ dL) was independently associated with CKD (eGFR <60 mL/ min / 1.73 m(2)) (odds ratio, 2.63; 95% confidence interval, 1.61-4.3; P<.001). In hypertensive women, the presence of hyperuricemia indicated a substantial degree of kidney dysfunction as well as a greater cardiovascular risk profile.

Role of N-glycosylation in trafficking of apical membrane proteins in epithelia

Polarized distribution of plasma membrane transporters and receptors in epithelia is essential for vectorial functions of epithelia. This polarity is maintained by sorting of membrane proteins into apical or basolateral transport containers in the trans-Golgi network and/or endosomes followed by their delivery to the appropriate plasma membrane domains. Sorting depends on the recognition of sorting signals in proteins by specific sorting machinery. In the present review, we summarize experimental evidence for and against the hypothesis that N-glycans attached to the membrane proteins can act as apical sorting signals. Furthermore, we discuss the roles of N-glycans in the apical sorting event per se and their contribution to folding and quality control of glycoproteins in the endoplasmic reticulum or retention of glycoproteins in the plasma membrane. Finally, we review existing hypotheses on the mechanism of apical sorting and discuss the potential roles of the lectins, VIP36 and galectin-3, as putative apical sorting receptors.

Redox features of the cell: a gender perspective

Reactive oxygen and nitrogen species have been implicated in diverse subcellular activities, including cell proliferation,differentiation and, in some instances, cell injury and death. The implications of reactive species inhuman pathology have also been studied in detail. However, although the role of free radicals in the pathogenesis of human diseases has been extensively analyzed in different systems (i.e., in vitro, ex vivo, and in vivo),it is still far from elucidated. In particular, the possible role of gender 4 differences in human pathophysiology associated with reactive species is a promising new field of investigation. Although the complex scenario this presents is still incomplete, important gender-associated "redox features" of cells have already been described in the literature. Here we summarize the different aspects of redox-associated molecules and enzymes in regard to gender differences in terms of the intracellular production and biochemical activity of reactive species. These are often associated with the pathogenetic mechanisms underlying several human morbidities(e.g., degenerative diseases) and can represent a specific target for new pharmacologic strategies. Gender differences may thus pose an important challenge for future studies aimed at the clinical management of diseases characterized by a redox imbalance.