The relation of postmenopausal hormone therapy to serum uric acid and the risk of coronary heart disease events: the Heart and Estrogen-Progestin Replacement Study (HERS)

Asymptomatic hyperuricemia: to treat or not a threat? A clinical and evidence-based approach to the management of hyperuricemia in the context of cardiovascular diseases

Asymptomatic hyperuricemia is defined by serum uric acid levels above 6.2 mg/dl in women and 7 mg/dl in men. In the presence of monosodium urate crystal formation and articular inflammation, hyperuricemia may become symptomatic (namely nephrolithiasis and gout). Uric acid results from purine catabolism and is at the centre of a complex metabolic interplay that involves oxidative stress, inflammation, renin-angiotensin-aldosterone system (RAAS) activation and insulin resistance. Uric acid levels present a continuous relation with conditions like hypertension and chronic kidney disease (CKD) and are reported to have an impact on risk of cardiovascular events. However, whether elevated uric acid is a causal agent and thus a possible therapeutic target is still uncertain and matter of further investigation. Treating symptomatic hyperuricemia involves lowering uric acid drugs and controlling inflammation. Urate-lowering agents are well tolerated but show minimal impact on cardiovascular events in patients with gout. Use of direct-acting urate-lowering agents in asymptomatic hyperuricemia associated with cardiovascular diseases does not warrant a clear benefit, whereas addressing cardiovascular issues with guideline-recommended therapies lowers uric acid and reduces the occurrence of cardiovascular events. Regular assessment of uric acid and clinical symptoms is advised before starting and renewing a urate-lowering treatment.

Comprehensive meta-analysis of the effects of oral medroxyprogesterone acetate plus conjugated equine oestrogens on the lipid profile in women: Insights from randomized controlled trials

BACKGROUND

Menopause is associated with elevated cardiovascular risk due to the loss of the cardioprotective effect of oestrogens. Postmenopausal women are often prescribed hormone replacement therapy (HRT) in order to control menopause symptoms and correct hormone imbalances; however, HRT can impact serum lipids' concentrations. At present, data on the effect of the administration of medroxyprogesterone acetate plus conjugated equine oestrogens (MPACEE) on the lipid profile in females are uncertain, as the investigations conducted so far have produced conflicting results. Thus, we aimed to clarify the impact of MPACEE prescription on the serum lipids' values in women by means of a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

We employed a random-effects model based on the DerSimonian and Laird method to determine the combined estimates of the intervention's impact on the lipid profile. The computation of the weighted mean difference (WMD) and its corresponding 95% confidence interval (CI) relied on the mean and standard deviation values from both the MPACEE and control group, respectively.

RESULTS

A total of 53 RCTs were included in the meta-analysis with 68 RCT arms on total cholesterol (TC), 70 RCT arms on low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG), and 69 RCT arms on high-density lipoprotein cholesterol (HDL-C). Administration of MPACEE resulted in a significant reduction of TC (WMD = -11.93 mg/dL; 95% CI: -13.42, -10.44; p < .001) and LDL-C (WMD = -16.61 mg/dL; 95% CI: -17.97, -15.26; p < .001) levels, and a notable increase in HDL-C (WMD = 3.40 mg/dL; 95% CI: 2.93, 3.86; p < .001) and TG (WMD = 10.28 mg/dL; 95% CI: 7.92, 12.64; p < .001) concentrations. Subgroup analysis revealed that changes in the lipid profile were influenced by several factors: body mass index (for TC, HDL-C, TG), MPACEE dosages (for TC, LDL-C, HDL-C, TG), age (for TC, LDL-C, HDL-C, TG), durations of the intervention (for TC, LDL-C, HDL-C, TG), continuous/sequential administration of MPACEE (continuous for TC; sequential for LDL-C, TG) administration of MPACEE and serum lipids' concentrations before enrolment in the RCT (for TC, LDL-C, HDL-C, TG).

CONCLUSIONS

MPACEE administration can influence serum lipids' concentrations in females by raising HDL-C and TG levels and reducing LDL-C and TC values. Therefore, postmenopausal women who suffer from hypercholesterolaemia might benefit from this type of HRT.

Association between female reproductive factors and gout: a nationwide population-based cohort study of 1 million postmenopausal women

BACKGROUND

Previous studies have shown that the incidence and risk factors of gout differs according to sex. However, little research has been done on the association between reproductive factors and gout. We conducted an analysis of a large nationwide population-based cohort of postmenopausal women to determine whether there is an association between reproductive factors and the incidence of gout.

METHODS

A total of 1,076,378 postmenopausal women aged 40-69 years who participated in national health screenings in 2009 were included in the study. The outcome was the occurrence of incident gout, which was defined using the ICD-10 code of gout (M10) in the claim database. Cox proportional hazard models were used for the analyses and stratified analyses according to body mass index (BMI) and the presence/absence of chronic kidney disease (CKD) were performed.

RESULTS

The mean follow-up duration was 8.1 years, and incident cases of gout were 64,052 (incidence rate 7.31 per 1000 person-years). Later menarche, earlier menopause, and a shorter reproductive span were associated with a high risk of gout. No association between parity and gout incidence was observed. Use of oral contraceptives (OC) and hormone replacement therapy (HRT) were associated with an increased risk of gout. The association between reproductive factors and gout was not statistical significant in the high BMI group. The effects of OC and HRT usage on gout were not significant in the CKD group.

CONCLUSION

Shorter exposure to endogenous estrogen was associated with a high risk of gout. Conversely, exposure to exogenous estrogen such as OC and HRT was associated with an increased risk of gout.

Should we be more aware of gender aspects in hyperuricemia? Analysis of the population-based German health interview and examination survey for adults (DEGS1)

OBJECTIVES

While gout is a well-known entity, little research has been conducted on its pathophysiology. There is growing evidence that women with hyperuricemia are at higher cardiovascular risk than men with hyperuricemia. We aim to evaluate whether gender-specific cut-offs should be considered.

STUDY DESIGN

Cross-sectional study (the German Health Interview and Examination Survey for Adults; DEGS1).

MAIN OUTCOME MEASURES

Self-reported gout or hyperuricemia and uric acid level.

RESULTS

Of 6,918 participants (mean age 47.2 years; 50.5% females), 9.7% had had a diagnosis of hyperuricemia or gout at least once in their lifetime. Men were nearly twice as often affected as women (12.9 vs. 6.5%). In women, the prevalence of cardiovascular and renal diseases increased with higher uric acid level to a much greater extent than in men. This association remained in multivariate analyses.

CONCLUSIONS

No commonly accepted cut-off value for uric acid has been established. Overall, women were at lower risk of hyperuricemia. However, women were at higher risk of having cardiovascular and renal comorbidities, even at lower uric acid levels. Our results are in line with the accumulating evidence that we should consider gender in gout and hyperuricemia.

Association between Serum Uric Acid and Non-Alcoholic Fatty Liver Disease according to Different Menstrual Status Groups

OBJECTIVE

The present study aimed to explore the association between SUA and NAFLD in women with different menstrual statuses.

METHODS

A total of 6043 women were selected from the Jidong and Kailuan communities for inclusion in the present study. The SUA levels of participants were divided into quartiles. NAFLD was determined by abdominal ultrasonography. Data from laboratory tests and clinical examination were collected, and basic information was obtained from standardized questionnaires. The menstrual status was stratified into menstrual period, menopause transition period, and postmenopause. Multivariate logistic regression models were used to determine the relationship between menstrual status, SUA, and NAFLD.

RESULTS

The levels of SUA in subjects with NAFLD in the menstrual period, menopause transition period, and postmenopause were 268.0 ± 71.1, 265.6 ± 67.8, and 286.7 ± 75.8 (mmol/L), respectively, and were higher than those in subjects without NAFLD. The adjusted odds ratios (ORs) with 95% confidence interval (CI) for NAFLD among participants in the menopause transition period and postmenopausal period were 1.10 (0.89-1.37) and 1.28 (1.04-1.58), respectively, compared with the menstrual period women. Compared to the lowest quartile of SUA, the adjusted ORs with 95% CI of the highest quartile for NAFLD were 2.24 (1.69-2.99) for females in the menstrual period, 1.92 (1.10-3.37) for females in the menopause transition period, and 1.47 (1.06-2.03) for females in postmenopause.

CONCLUSIONS

Menstrual status was significantly correlated with NAFLD. High levels of SUA were associated with NAFLD in females during the three menstrual periods.

Age-differential association between serum uric acid and incident hypertension

Increasing evidence suggests a positive association between the serum uric acid (SUA) level and incident hypertension. However, the association has been inconsistent based on age, sex, body mass index, and lipid profiles. Thus, we investigated whether there is an interaction between SUA and other risk factors on incident hypertension in the Korean general population. In this study, 808 participants aged 40-79 years were included. They were free of hypertension and major cardiovascular disease at baseline. Incident hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg, diastolic blood pressure (DBP) ≥ 90 mmHg, or use of antihypertensive medication. To investigate whether the association between SUA and incident hypertension is modified by other risk factors for hypertension, a generalized linear model and Z test were used. During the mean follow-up of 3.3 years, 11.5% of men and 10.7% of women developed hypertension. The association between SUA and incident hypertension was inconsistent according to participant age (p for interaction = 0.009). The association between SUA level and incident hypertension was positively significant among people aged < 55 years (relative risk 1.74 per 1.0 mg/dL of SUA; p = 0.002), but there was no significant association among people aged ≥ 55 years (p = 0.894). In a secondary analysis, the SUA level was not associated with an increase in SBP, but positively associated with DBP. We observed an age-differential association between SUA level and incident hypertension among Koreans. An increased SUA level can be a trigger for hypertension through early vascular changes in the middle-aged population.

Gender Differences in the Association between Serum Uric Acid and Prediabetes: A Six-Year Longitudinal Cohort Study

This study aimed to examine gender differences in the association between serum uric acid (SUA) and the risk of prediabetes in a longitudinal cohort. A total of 8237 participants in the Beijing Health Management Cohort study were recruited and surveyed during 2008⁻2009, and followed up in 2011⁻2012 and 2014⁻2015 surveys. Generalized estimating equation (GEE) models were used to evaluate the association between SUA and prediabetes. Furthermore, subgroup analyses assessed the primary outcome according to status of abdominal obesity, age and status of hypertension. During six years of follow-up, we identified 1083 prediabetes events. The GEE analyses confirmed and clarified the association between SUA and prediabetes (RR = 1.362; 95% CI = 1.095⁻1.696; p = 0.006) after adjusting for other potential confounders, especially in females (RR = 2.109; 95% CI = 1.329⁻3.347; p = 0.002). In addition, this association was stronger in the subgroup of females aged ≥48 years old (RR = 2.384; 95% CI = 1.417⁻4.010; p = 0.001). The risk for prediabetes increased significantly with increasing SUA for females in the Chinese population. This association was strongly confirmed in older females aged ≥48 years old rather than in younger females, which may provide clues for pathogenic mechanisms of gender differences in the association between SUA and prediabetes.

Uric Acid Is Associated With Inflammation, Coronary Microvascular Dysfunction, and Adverse Outcomes in Postmenopausal Women

Uric acid is a risk factor for coronary artery disease in postmenopausal women, but the association with inflammation and coronary endothelial dysfunction (CED) is not well defined. The aim of this study was to determine the relationship of serum uric acid (SUA), inflammatory markers, and CED. In this prospective cohort study, SUA, high-sensitivity C-reactive protein levels, and neutrophil count were measured in 229 postmenopausal women who underwent diagnostic catheterization, were found to have no obstructive coronary artery disease, and underwent coronary microvascular function testing, to measure coronary blood flow response to intracoronary acetylcholine. The average age was 58 years (interquartile range, 52-66 years). Hypertension was present in 48%, type 2 diabetes mellitus in 5.6%, and hyperlipidemia in 61.8%. CED was diagnosed in 59% of postmenopausal women. Mean uric acid level was 4.7±1.3 mg/dL. Postmenopausal women with CED had significantly higher SUA compared with patients without CED (4.9±1.3 versus 4.4±1.3 mg/dL; P=0.02). There was a significant correlation between SUA and percent change in coronary blood flow to acetylcholine (P=0.009), and this correlation persisted in multivariable analysis. SUA levels were significantly associated with increased neutrophil count (P=0.02) and high-sensitivity C-reactive protein levels (P=0.006) among patients with CED, but not among those without CED. SUA is associated with CED in postmenopausal women and may be related to inflammation. These findings link SUA levels to early coronary atherosclerosis in postmenopausal women.

Association of SLC2A9 genotype with phenotypic variability of serum urate in pre-menopausal women

The SLC2A9 gene, that encodes a renal uric acid reuptake transporter, has genetic variants that explain ∼3% of variance in urate levels. There are previous reports of non-additive interaction between SLC2A9 genotype and environmental factors which influence urate control. Therefore, our aim was to further investigate the general phenomenon that such non-additive interactions contribute to genotype-specific association with variance at SLC2A9. Data from 14135 European individuals were used in this analysis. The measure of variance was derived from a ranked inverse normal transformation of residuals obtained by regressing known urate-influencing factors (sex, age, and body mass index) against urate. Variant rs6449173 showed the most significant effect on serum urate variance at SLC2A9 (P = 7.9 × 10^-14), which was maintained after accounting for the effect on average serum urate levels (P = 0.022). Noting the stronger effect in a sub-cohort that consisted of pre-menopausal women and younger men, the participants were stratified into males and pre-menopausal and post-menopausal women. This revealed a strong effect on variance in pre-menopausal women (P = 3.7 × 10^-5) with a weak effect in post-menopausal women (P = 0.032) and no effect in men (P = 0.22). The T-allele of rs6449173, which associates with increased urate levels, was associated with the greater variance in urate. There was a non-additive interaction between rs6449173 genotype and female gender in control of serum urate levels that was driven by a greater increase in urate levels associated with the T-allele in women. Female hormones, and/or other factors they influence or are associated with (such as iron levels, temperature, testosterone) interact with SLC2A9 genotype in women to determine urate levels. The association of SLC2A9 with greater variance in pre-menopausal women may reflect the cyclical changes resulting from menstruation.

Uric acid is an independent predictor of cardiovascular events in post-menopausal women

BACKGROUND

Uric acid (UA) is a risk factor for cardiovascular (CV) disease. In post-menopause UA levels are increased and strongly associated with subclinical organ damage. We investigated the prognostic significance of UA levels in predicting CV morbidity and mortality in post-menopausal women.

METHODS

We considered 645 post-menopausal outpatients not taking hormone replacement therapy or any drugs interfering with UA levels. We evaluated major adverse cardiovascular events (MACE) as primary endpoint, with coronary, stroke or total events as secondary endpoint. Survival curves for tertiles of UA were obtained by using the Kaplan-Meier and Mantel methods. Effect of prognostic factors on survival was evaluated by multivariable Cox regression model, considering P<0.05 as statistically significant.

RESULTS

During a mean (SD) follow-up at 72.5 (23.5) months, there were 90 new CV events (2.31%): 62 coronary and 28 cerebrovascular events. The rate of nonfatal CV events (3.15% versus 2.03% and 1.52%, P=0.009) as well as that of MACE (3.23% versus 2.11% and 1.59%, P=0.011) were significantly higher in the third tertile than in the other two groups. Interestingly, cerebrovascular (1.15% versus 0.62% and 0.30%, P=0.027) but not coronary events were significantly different among the three groups. In the Cox regression model, UA was independently and strongly associated with the incident risk of MACE (HR=1.248, P=0.001), cerebrovascular (HR=1.657, P<0.0001) and total events (HR=1.391, P<0.0001).

CONCLUSIONS

In post-menopause, independently of other CV risk factors and menopause duration, UA levels are associated with increased risk of death and MACE, in particular cerebrovascular but not coronary events.

Hormone therapy for preventing cardiovascular disease in post-menopausal women

BACKGROUND

Evidence from systematic reviews of observational studies suggests that hormone therapy may have beneficial effects in reducing the incidence of cardiovascular disease events in post-menopausal women, however the results of randomised controlled trials (RCTs) have had mixed results. This is an updated version of a Cochrane review published in 2013.

OBJECTIVES

To assess the effects of hormone therapy for the prevention of cardiovascular disease in post-menopausal women, and whether there are differential effects between use in primary or secondary prevention. Secondary aims were to undertake exploratory analyses to (i) assess the impact of time since menopause that treatment was commenced (≥ 10 years versus < 10 years), and where these data were not available, use age of trial participants at baseline as a proxy (≥ 60 years of age versus < 60 years of age); and (ii) assess the effects of length of time on treatment.

SEARCH METHODS

We searched the following databases on 25 February 2014: Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and LILACS. We also searched research and trials registers, and conducted reference checking of relevant studies and related systematic reviews to identify additional studies.

SELECTION CRITERIA

RCTs of women comparing orally administered hormone therapy with placebo or a no treatment control, with a minimum of six months follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for each outcome. We combined results using random effects meta-analyses, and undertook further analyses to assess the effects of treatment as primary or secondary prevention, and whether treatment was commenced more than or less than 10 years after menopause.

MAIN RESULTS

We identified six new trials through this update. Therefore the review includes 19 trials with a total of 40,410 post-menopausal women. On the whole, study quality was good and generally at low risk of bias; the findings are dominated by the three largest trials. We found high quality evidence that hormone therapy in both primary and secondary prevention conferred no protective effects for all-cause mortality, cardiovascular death, non-fatal myocardial infarction, angina, or revascularisation. However, there was an increased risk of stroke in those in the hormone therapy arm for combined primary and secondary prevention (RR 1.24, 95% CI 1.10 to 1.41). Venous thromboembolic events were increased (RR 1.92, 95% CI 1.36 to 2.69), as were pulmonary emboli (RR 1.81, 95% CI 1.32 to 2.48) on hormone therapy relative to placebo.The absolute risk increase for stroke was 6 per 1000 women (number needed to treat for an additional harmful outcome (NNTH) = 165; mean length of follow-up: 4.21 years (range: 2.0 to 7.1)); for venous thromboembolism 8 per 1000 women (NNTH = 118; mean length of follow-up: 5.95 years (range: 1.0 to 7.1)); and for pulmonary embolism 4 per 1000 (NNTH = 242; mean length of follow-up: 3.13 years (range: 1.0 to 7.1)).We performed subgroup analyses according to when treatment was started in relation to the menopause. Those who started hormone therapy less than 10 years after the menopause had lower mortality (RR 0.70, 95% CI 0.52 to 0.95, moderate quality evidence) and coronary heart disease (composite of death from cardiovascular causes and non-fatal myocardial infarction) (RR 0.52, 95% CI 0.29 to 0.96; moderate quality evidence), though they were still at increased risk of venous thromboembolism (RR 1.74, 95% CI 1.11 to 2.73, high quality evidence) compared to placebo or no treatment. There was no strong evidence of effect on risk of stroke in this group. In those who started treatment more than 10 years after the menopause there was high quality evidence that it had little effect on death or coronary heart disease between groups but there was an increased risk of stroke (RR 1.21, 95% CI 1.06 to 1.38, high quality evidence) and venous thromboembolism (RR 1.96, 95% CI 1.37 to 2.80, high quality evidence).

AUTHORS' CONCLUSIONS

Our review findings provide strong evidence that treatment with hormone therapy in post-menopausal women overall, for either primary or secondary prevention of cardiovascular disease events has little if any benefit and causes an increase in the risk of stroke and venous thromboembolic events.

Estrogen, vascular estrogen receptor and hormone therapy in postmenopausal vascular disease

Cardiovascular disease (CVD) is less common in premenopausal women than men of the same age or postmenopausal women, suggesting vascular benefits of estrogen. Estrogen activates estrogen receptors ERα, ERβ and GPR30 in endothelium and vascular smooth muscle (VSM), which trigger downstream signaling pathways and lead to genomic and non-genomic vascular effects such as vasodilation, decreased VSM contraction and growth and reduced vascular remodeling. However, randomized clinical trials (RCTs), such as the Women's Health Initiative (WHI) and Heart and Estrogen/progestin Replacement Study (HERS), have shown little vascular benefits and even adverse events with menopausal hormone therapy (MHT), likely due to factors related to the MHT used, ER profile, and RCT design. Some MHT forms, dose, combinations or route of administration may have inadequate vascular effects. Age-related changes in ER amount, distribution, integrity and post-ER signaling could alter the vascular response to MHT. The subject's age, preexisting CVD, and hormone environment could also reduce the effects of MHT. Further evaluation of natural and synthetic estrogens, phytoestrogens, and selective estrogen-receptor modulators (SERMs), and the design of appropriate MHT combinations, dose, route and 'timing' could improve the effectiveness of conventional MHT and provide alternative therapies in the peri-menopausal period. Targeting ER using specific ER agonists, localized MHT delivery, and activation of specific post-ER signaling pathways could counter age-related changes in ER. Examination of the hormone environment and conditions associated with hormone imbalance such as polycystic ovary syndrome may reveal the causes of abnormal hormone-receptor interactions. Consideration of these factors in new RCTs such as the Kronos Early Estrogen Prevention Study (KEEPS) could enhance the vascular benefits of estrogen in postmenopausal CVD.

Vascular effects of estrogenic menopausal hormone therapy

Cardiovascular disease (CVD) is more common in men and postmenopausal women (Post-MW) than premenopausal women (Pre-MW). Despite recent advances in preventive measures, the incidence of CVD in women has shown a rise that matched the increase in the Post-MW population. The increased incidence of CVD in Post-MW has been related to the decline in estrogen levels, and hence suggested vascular benefits of endogenous estrogen. Experimental studies have identified estrogen receptor ERα, ERβ and a novel estrogen binding membrane protein GPR30 (GPER) in blood vessels of humans and experimental animals. The interaction of estrogen with vascular ERs mediates both genomic and non-genomic effects. Estrogen promotes endothelium-dependent relaxation by increasing nitric oxide, prostacyclin, and hyperpolarizing factor. Estrogen also inhibits the mechanisms of vascular smooth muscle (VSM) contraction including [Ca2+]i, protein kinase C and Rho-kinase. Additional effects of estrogen on the vascular cytoskeleton, extracellular matrix, lipid profile and the vascular inflammatory response have been reported. In addition to the experimental evidence in animal models and vascular cells, initial observational studies in women using menopausal hormonal therapy (MHT) have suggested that estrogen may protect against CVD. However, randomized clinical trials (RCTs) such as the Heart and Estrogen/ progestin Replacement Study (HERS) and the Women's Health Initiative (WHI), which examined the effects of conjugated equine estrogens (CEE) in older women with established CVD (HERS) or without overt CVD (WHI), failed to demonstrate protective vascular effects of estrogen treatment. Despite the initial set-back from the results of MHT RCTs, growing evidence now supports the 'timing hypothesis', which suggests that MHT could increase the risk of CVD if started late after menopause, but may produce beneficial cardiovascular effects in younger women during the perimenopausal period. The choice of an appropriate MHT dose, route of administration, and estrogen/progestin combination could maximize the vascular benefits of MHT and minimize other adverse effects, especially if given within a reasonably short time after menopause to women that seek MHT for the relief of menopausal symptoms.

Significance of serum uric acid levels on the risk of all-cause and cardiovascular mortality

OBJECTIVE

To assess the associations between serum uric acid (SUA) level and mortality.

METHODS

The study included 354 110 subjects without a history of gout and whose SUA levels were tested at Chang Gung Memorial Hospital in Taiwan. Cox regression models were used to estimate hazard ratios and 95% CIs for mortality in six predefined SUA strata (≤0.17, 0.18-0.29, 0.30-0.41, 0.42-0.53, 0.54-0.65 and ≥0.66 mmol/l), after adjusting for age, sex, SUA stratum, estimated glomerular filtration rate, fasting glucose, total cholesterol and history of hypertension, diabetes mellitus, coronary heart disease, stroke, heart failure or chronic kidney disease.

RESULTS

There were 33 562 all-cause deaths during the study period. Crude all-cause mortality rates across the SUA strata were 52.5, 19.7, 17.4, 20.0, 28.0 and 41.1 deaths per 1000 person-years. Using the stratum 3 of SUA as a reference, the age- and sex-adjusted hazard ratios (95% CIs) across SUA strata were 2.79 (2.62, 2.96), 1.32 (1.28, 1.36), 1.00, 1.10 (1.07, 1.14), 1.42 (1.37, 1.48) and 2.12 (2.01, 2.23) for all-cause mortality; 2.24 (1.93, 2.59), 1.18 (1.10, 1.27), 1.00, 1.21 (1.14, 1.29), 1.74 (1.60, 1.88) and 2.53 (2.28, 2.81) for cardiovascular mortality and 3.41 (3.11, 3.73), 1.48 (1.42, 1.55), 1.00, 0.88 (0.84, 0.92), 0.91 (0.85, 0.98) and 1.23 (1.11, 1.36) for cancer-related mortality.

CONCLUSION

Individuals with SUA levels at either extremes are at higher risk for all-cause and cardiovascular mortality. SUA levels of 0.30-0.41 mmol/l were associated with the lowest mortality rate and should be regarded as optimal.

Reproductive factors and serum uric acid levels in females from the general population: the KORA F4 study

Objective

Hyperuricemia is associated with an increased risk of metabolic and cardiovascular diseases. There are pronounced sex differences in the levels of uric acid. It is largely unknown whether or not reproductive parameters which induce hormonal changes are responsible for this. We examined if there are associations between reproductive parameters and uric acid levels in a female population-based sample.

Methods

In this cross-sectional analysis, data of 1530 women aged 32 to 81 years participating in the KORA F4 study, conducted between 2006 and 2008 in Southern Germany were used. Reproductive parameters were obtained by standardized interviews. Uric acid levels were tested by the uricase method. The whole study sample and stratified in pre- and postmenopausal women was analyzed.

Results

Menopausal status and earlier age at menarche were associated with higher serum uric acid levels (age-adjusted: p-values 0.003, <0.001 respectively; after multivariable adjustment, including BMI: p-values 0.002, 0.036). A history of oral contraceptive use showed an association with uric acid levels only after multivariable adjustment (p-value 0.009). Hot flushes showed an association with uric acid levels only after age-adjustment (p-value 0.038), but lost significance after adding other confounders. Other reproductive factors, including parity, current or ever use of hormone replacement therapy, current use of oral contraceptives, hysterectomy, bilateral oophorectomy, or depressive mood related to menopausal transition were not associated with uric acid levels.

Conclusions

Postmenopausal status, earlier age at menarche and a history of oral contraceptive use were independently associated with higher serum uric acid concentrations in women from the general population. Further studies, especially longitudinal population-based studies investigating the relationship of female reproductive parameters with uric acid levels are necessary to confirm our findings.

The epidemiology of uric acid and fructose

During the past few decades, the mean serum uric acid levels and the prevalence of hyperuricemia in the general population appear to have increased. Correspondingly, the prevalence and incidence of gout have doubled. Potential reasons behind these trends include the increasing prevalence of obesity and metabolic syndrome, Western lifestyle factors, increased prevalence of medical conditions (eg, renal conditions, hypertension, and cardiovascular disorders), and use of medications that increase uric acid levels (eg, diuretics and low-dose aspirin). The substantial increase in sugar-sweetened soft drinks and associated fructose consumption also has coincided with the secular trend of hyperuricemia and gout. Recently, several large-scale epidemiologic studies have clarified a number of these long-suspected risk factors in relation with hyperuricemia and gout. Furthermore, recent studies have illuminated the substantial comorbidities of hyperuricemia and gout, particularly metabolic-cardiovascular-renal conditions. Although many prospective studies have suggested an independent association between serum uric acid levels and the future risk of cardiovascular-metabolic morbidities and mortality, only a limited number of randomized clinical trials and observational studies recently have shown that the use of allopurinol can be beneficial against these outcomes. Because these data are scarce and the effects of allopurinol might not be limited to decreasing serum uric acid levels, the potential causal role of uric acid on these outcomes remains to be clarified with further studies.

Biomarkers for predicting postmenopausal coronary heart disease

Coronary heart disease (CHD) is the main cause of death in post-menopausal women (PMW). Beyond the ‘traditional’ cardiovascular risk factors of CHD, newer biomarkers, reflecting inflammation, endothelial function and oxidative stress, have received growing consideration. We systematically reviewed the literature on the biomarkers for predicting CHD in PMW. C-reactive protein, IL-6 and Lipoprotein (a) have been consistently found to be associated with CHD risk in PMW. However, no evidence supports the existence of a causal and independent link between such biomarkers and CHD in PMW. Also, the new biomarkers only marginally improve cardiovascular risk prediction. Upcoming studies are needed to provide further evidence on the validity of the new biomarkers in PMW and to understand their relationships with hormone therapy, opening new avenues for prevention.

Relationship between uric acid and metabolic syndrome according to menopausal status

OBJECTIVE

Uric acid, the levels of which have been shown to increase after menopause, has been associated with metabolic syndrome. The prevalence of metabolic syndrome has also been determined to increase after menopause. Therefore, we surmised that menopausal status-specific analyses for the characterisation of the relationship between uric acid and the metabolic syndrome were warranted.

METHODS

We included 1644 patients: 1018 premenopausal women and 626 postmenopausal women, all of whom participated in annual health examinations at Anam Hospital in Seoul, Korea, from January 2008 through December 2008.

RESULTS

On the multivariate logistic regression analysis, uric acid was identified as an independent risk factor for metabolic syndrome in both premenopausal and postmenopausal women. Uric acid levels had different relationships with blood pressure based on menopausal status, however, no such relationships with fasting glucose or age were found.

CONCLUSIONS

Increased uric acid levels were associated with increased risk for metabolic syndrome in both premenopausal and postmenopausal women. In studies regarding uric acid and metabolic syndrome in women, the effects of menopausal status should be considered.

Research into Specific Modulators of Vascular Sex Hormone Receptors in the Management of Postmenopausal Cardiovascular Disease

Cardiovascular disease (CVD) is more common in men and postmenopausal women than premenopausal women, suggesting vascular benefits of female sex hormones. Studies on the vasculature have identified estrogen receptors ERα, ERβ and a novel estrogen binding membrane protein GPR30, that mediate genomic and/or non-genomic effects. Estrogen promotes endothelium-dependent relaxation by inducing the production/activity of nitric oxide, prostacyclin, and hyperpolarizing factor, and inhibits the mechanisms of vascular smooth muscle contraction including [Ca(2+)](i), protein kinase C, Rho kinase and mitogen-activated protein kinase. Additional effects of estrogen on the cytoskeleton, matrix metalloproteinases and inflammatory factors contribute to vascular remodeling. However, the experimental evidence did not translate into vascular benefits of menopausal hormone therapy (MHT), and the HERS, HERS-II and WHI clinical trials demonstrated adverse cardiovascular events. The discrepancy has been partly related to delayed MHT and potential changes in the vascular ER amount, integrity, affinity, and downstream signaling pathways due to the subjects' age and preexisting CVD. The adverse vascular effects of MHT also highlighted the need of specific modulators of vascular sex hormone receptors. The effectiveness of MHT can be improved by delineating the differences in phramcokinetics and pharmacodynamics of natural, synthetic, and conjugated equine estrogens. Estriol, "hormone bioidenticals" and phytoestrogens are potential estradiol substitutes. The benefits of low dose MHT, and transdermal or vaginal estrogens over oral preparations are being evaluated. Specific ER modulators (SERMs) and ER agonists are being developed to maximize the effects on vascular ERs. Also, the effects of estrogen are being examined in the context of the whole body hormonal environment and the levels of progesterone and androgens. Thus, the experimental vascular benefits of estrogen can be translated to the outcome of MHT in postmenopausal CVD, as more specific modulators of sex hormone receptors become available and are used at the right dose, route of administration and timing, depending on the subject's age and preexisting cardiovascular condition.

Menopause, postmenopausal hormone use and risk of incident gout

OBJECTIVE

To prospectively study the relation between menopause, postmenopausal hormone use and risk of gout, since female sex hormones have been postulated to decrease gout risk among women.

METHODS

In the Nurses' Health Study, the association between menopause, age at menopause, postmenopausal hormone use and risk of self-reported physician-diagnosed incident gout among 92 535 women without gout at baseline was examined. Multivariate proportional hazards regression analysis was used to adjust for other risk factors for gout such as age, body mass index, diuretic use, hypertension, alcohol intake and dietary factors.

RESULTS

During 16 years of follow-up (1 240 231 person-years), 1703 incident gout cases were recorded. The incidence rate of gout increased from 0.6 per 1000 person-years in women <45 years of age to 2.5 in women > or =75 years of age (p for trend <0.001). Compared with premenopausal women, postmenopausal women had a higher risk of incident gout (multivariate-adjusted relative risk (RR)=1.26; 95% confidence interval (CI) 1.03 to 1.55). Among women with a natural menopause, women with age at menopause <45 years had a RR of 1.62 (95% CI 1.12 to 2.33) of gout compared with women with age at menopause 50-54 years. Postmenopausal hormone users had a reduced risk of gout (RR=0.82; 95% CI 0.70 to 0.96).

CONCLUSION

These prospective findings indicate that menopause increases the risk of gout, whereas postmenopausal hormone therapy modestly reduces gout risk.

Serum urate, menopause, and postmenopausal hormone use: from eminence to evidence-based medicine

The relationship between serum urate, menopause, and aging has not been clearly defined by scientific evidence. In the present issue of Arthritis Research and Therapy, Hak and Choi present a cross-sectional analysis to clarify the effect of menopause and hormone replacement therapy on serum urate in women within the Third National Health and Nutritional Examination Survey. Menopause increased serum urate and hormone replacement therapy significantly decreased serum urate, although the overall level of change was small. The implications of these urate changes on gout and cardiovascular disease outcomes require further study.

Menopause, postmenopausal hormone use and serum uric acid levels in US women--the Third National Health and Nutrition Examination Survey

Introduction

Despite the substantial prevalence of gout in the ageing female population, female hormonal influence has not been comprehensively examined. We evaluated and quantified the potential independent association between menopause, postmenopausal hormone use and serum uric acid levels in a nationally representative sample of women.

Methods

Using data from 7662 women aged 20 years and older in the Third National Health and Nutrition Examination Survey (1988 to 1994), we examined the relation between menopause, postmenopausal hormone use and serum uric acid levels. We used multivariate linear regression to adjust for other risk factors for hyperuricaemia such as dietary factors, age, adiposity, alcohol use, renal function, hypertension and diuretic use.

Results

Menopause was associated with higher serum uric acid levels. After adjusting for covariates, serum uric acid levels among women with natural menopause and surgical menopause were greater than premenopausal women by 0.34 mg/dl (95% confidence interval [CI], 0.19 to 0.49) and 0.36 mg/dl (95% CI, 0.14 to 0.57), respectively. Current postmenopausal hormone use was associated with a lower serum uric acid level among postmenopausal women (multivariate difference, 0.24 mg/dl [95% CI, 0.11 to 0.36]). The serum uric acid levels increased with increasing age categories (crude difference between 20 to 29 years and 70 years and over = 1.03 mg/dl, p for trend < 0.001), but this increase was not present after adjusting for other covariates (p for trend = 0.66).

Conclusions

These findings from a nationally representative sample of US women indicate that menopause is independently associated with higher serum uric acid levels, whereas postmenopausal hormone use is associated with lower uric acid levels among postmenopausal women. The age-associated increase in serum uric acid levels in women may be explained by menopause and other age-related factors.

Independent association of high serum uric acid concentration with angiographically defined coronary artery disease

Epidemiological studies have shown that a high serum uric acid concentration is a risk factor for coronary artery disease (CAD). However, the issue of whether it is an independent cardiovascular risk factor or simply a marker of co-existing conditions is a matter of controversy. In the present case-controlled study, we explored the association between serum uric acid and angiographically defined CAD in middle-aged subjects (356 CAD patients and 350 healthy individuals). Serum uric acid in CAD patients was significantly higher than that in healthy individuals (359 +/- 88.7 and 289 +/- 79.3 micromol/l, respectively, p < 0.01) and remained significantly higher after adjusting for confounding factors (F = 79.77, p < 0.01). The association between uric acid and CAD was not limited to the hyperuricemic range of values, but was also found in the high-normal range (p < 0.01). An unadjusted odds ratio (OR) of 5.0 was obtained in both genders (p < 0.01). Female patients with > 50% stenosis (clinically significant CAD), regardless of the number of diseased vessels, had higher uric acid concentrations than those with < 50% stenosis even after adjusting for confounders (F = 3.79, p = 0.01). In conclusion, we have demonstrated that high serum uric acid is independently associated with CAD and that uric acid determination could be useful as one of the markers of clinically significant CAD.

Serum uric acid as a risk factor for cardiovascular and renal disease: an old controversy revived

Hyperuricemia is commonly associated with traditional risk factors such as abnormalities in glucose metabolism, dyslipidemia, and hypertension. Recent studies have revived the controversy over the role of serum uric acid as an independent prognostic factor for cardiovascular mortality. The authors review clinical and experimental evidence concerning the role of serum uric acid in the development of cardiovascular and renal damage. Results of trials suggesting that serum uric acid variations over time may have a prognostic impact are also discussed.

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

Elevated serum uric acid (SUA) levels are commonly seen in patients with the metabolic syndrome (MetS). Several mechanisms, both direct and indirect, connect the increased SUA levels with the established diagnostic criteria of MetS. It is possible that the increased cardiovascular disease risk associated with the MetS is partially attributed to elevated circulating SUA concentration. Several drugs used in the treatment of MetS may alter SUA levels. Thus, lifestyle measures together with the judicious selection of drugs for the treatment of hypertension, dyslipidemia, and insulin resistance associated with MetS may result in a reduction of SUA levels and possibly cardiovascular disease risk. This review summarizes the pathophysiologic association between SUA and MetS and focuses on the prevention of hyperuricemia and its cardiovascular consequences.