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

Postmenopausal status increases the risk of uric acid stones

OBJECTIVE

This study investigated the impact of menopause on stone composition in women with urolithiasis.

STUDY DESIGN

A cross-sectional study was conducted from March 2013 to March 2018. Women with urolithiasis patients were divided into two groups according to their menopause status.

MAIN OUTCOME MEASURES

The clinical demographic characteristics, stone removal, stone composition, and urine chemistry were investigated. Univariate and multivariate survival analyses were performed to identify risk factors for the risk of uric acid stones.

RESULTS

Our study enrolled 1221 female patients with stone diseases, 783 (64.1 %) of whom were postmenopausal (66 patients surgically menopause and 717 patients naturally menopause). Postmenopausal women had higher rates of diabetes and hyperuricemia, a higher serum uric acid level, a higher urinary specific gravity, and a lower estimated glomerular filtration rate. Stone analysis revealed calcium oxalate stones in 66.2 % of the patients, apatite stones in 19.4 %, calcium oxalate and calcium phosphate stones in 7.7 %, uric acid stones in 4.4 %, struvite stones in 2.0 %, and brushite stones in 0.2 %. Postmenopausal women had a higher rate of uric acid stones. Multivariate analysis confirmed that postmenopausal status and hyperuricemia were independent risk factors of uric acid stones. Postmenopausal women required more invasive procedures to remove the stones, and they had lower self-voiding rates.

CONCLUSIONS

Postmenopausal women had higher rates of stone episodes, specifically related to uric acid stones. Given the prevalence and impact of chronic kidney diseases, factors that impede optimal renal function management in women must be identified to provide tailored treatment recommendations.

Elevated blood pressure and hyperuricemia risk: a retrospective cohort study from Wuhu, China

Although the relationship between hypertension and hyperuricemia is widely recognized, there is still a relative lack of research on prehypertensive individuals and the individual associations of systolic and diastolic blood pressure with the risk of hyperuricemia. From 2011 to 2016, we conducted a study on 53,323 individuals at Wuhu City Hospital in China. Based on initial blood pressure readings, participants were categorized into normal, prehypertension, or hypertension groups. We used Cox regression to analyze the associations with baseline factors. In subgroup analyses, systolic and diastolic pressures were treated as continuous variables, and their relationship with the risk of hyperuricemia was examined using restricted cubic spline analysis. The risk increased in the prehypertension and hypertension groups compared to the normal blood pressure group, with hazard ratios of 1.192 and 1.350, respectively. For each unit increase in blood pressure, the risk of hyperuricemia rose by 0.8% (systolic) and 0.9% (diastolic), especially when blood pressure levels exceeded 115/78 mmHg. Additionally, we observed that factors such as gender, alcohol consumption habits, obesity, and dyslipidemia might further influence this association. These findings emphasize the importance of early risk assessment and intervention in these patient populations in clinical practice.

Serum uric acid to creatinine ratio is a useful predictor of all-cause mortality among hypertensive patients

BACKGROUND

Many of the existing research studies have shown that serum uric acid (SUA) is a predictor of renal disease progression. More recently, studies have suggested an association between renal function-normalized SUA and all-cause mortality in adults. This study aims to examine the association between the ratio of SUA to creatinine (SUA/Cr) and all-cause mortality with a focus on hypertensive patients.

METHODS

This study is based on 2,017 participants, of whom 916 were male (mean age, 67 ± 11 years) and 1,101 were female (mean age, 69 ± 9 years). All participants were part of the Nomura Cohort Study in 2002 (cohort 1) and 2014 (cohort 2), as well as the follow-up period (2002 follow-up rate, 94.8%; 2014 follow-up rate, 98.0%). We obtained adjusted relative risk estimates for all-cause mortality from a basic resident register. In addition, we employed a Cox proportional hazards model and adjusted it for possible confounders to determine the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Of the total participants, 639 (31.7%) were deceased; of these, 327 (35.7%) were male and 312 (28.3%) were female. We found an independent association between a higher ratio of SUA/Cr and a higher risk of all-cause mortality in female participants only (HR, 1.10; 95% CI, 1.02-1.18). The multivariable-adjusted HRs (95% CI) for all-cause mortality across quintiles of baseline SUA/Cr were 1.28 (0.91-1.80), 1.00, 1.38 (0.95-1.98), 1.37 (0.94-2.00), and 1.57 (1.03-2.40) for male participants, and 0.92 (0.64-1.33), 1.00, 1.04 (0.72-1.50), 1.56 (1.06-2.30), and 1.59 (1.06-2.38) for female participants. When the data were further stratified on the basis of age (< 65 or ≥ 65 years), body mass index (< 22.0 or ≥ 22.0 kg/m²), estimated glomerular filtration rate (< 60 or ≥ 60 mL/min/1.73 m²), and presence of SUA-lowering medication, trends similar to those of the full population were found in all groups.

CONCLUSION

Baseline SUA/Cr is independently and significantly associated with future all-cause mortality among hypertensive patients.

Prevalence of hyperuricemia and the population attributable fraction of modifiable risk factors: Evidence from a general population cohort in China

Data on updated hyperuricemia prevalence in Beijing-Tianjin-Hebei (BTH) region in China, which is one of the world-class urban agglomerations, is sparse. Overweight/obesity, alcohol consumption, smoking and sedentary behavior are modifiable risk factors (MRFs) for elevated serum uric acid (SUA), but their population attributable fractions (PAFs) for hyperuricemia is still unclear. Using baseline data from the BTH Physical Examination General Population Cohort, we calculated the crude- and adjusted-prevalence of hyperuricemia based on the 30,158 participants aged 18–80 years. Hyperuricemia was defined as SUA >420 μmol/L in men and >360 μmol/L in women, or currently use of uric acid lowering drugs. Overweight/obesity, alcohol consumption, smoking and sedentary behavior were considered as MRFs and their adjusted PAFs were estimated. The prevalence of hyperuricemia was 19.37%, 27.72% in men and 10.69% in women. The PAFs and 95% confidence intervals for overweight, obesity were 16.25% (14.26–18.25%) and 12.08% (11.40–12.77%) in men, 13.95% (12.31–15.59%) and 6.35% (5.97–6.74%) in women, respectively. Alcohol consumption can explain 4.64% (2.72–6.56%) hyperuricemia cases in men, but with no statistical significance in women. Cigarette smoking contributed to 3.15% (1.09–5.21%) cases in men, but a much lower fraction in women (0.85%, 0.49–1.22%). Compared with sedentary time <2 h per day, the PAFs of 2–4 h, 4–6 h, and more than 6 h per day were 3.14% (1.34–4.93%), 6.72% (4.44–8.99%) and 8.04% (4.95–11.13%) in men, respectively. Sedentary time was not found to be associated with hyperuricemia in women. These findings concluded that hyperuricemia is prevalent in this representative Chinese adult general population with substantial sex difference. Four MRFs (overweight/obesity, alcohol consumption, cigarette smoking and sedentary behavior) accounted for a notable proportion of hyperuricemia cases. The PAF estimations enable the exploration of the expected proportion of hyperuricemia cases that could be prevented if the MRFs were removed, which warrants the public health significance of life-style intervention.

Hyperuricemia is associated with all-cause mortality among males and females: Findings from a study on Japanese community-dwelling individuals

Background

Serum uric acid (SUA) is a key determinant of cardiovascular diseases (CVDs). Studies have also shown that SUA independently impacts age-related health outcomes, although their findings differ between males and females. Furthermore, predictive data on all-cause mortality remain limited, particularly for the Japanese population. Thus, this study examined the association between SUA and survival prognosis among males and females based on a follow-up period of 7 or 19 years.

Methods

The study was based on 1,573 male (63 ± 14 years) and 1,980 female (65 ± 12 years) participants who participated in a Nomura Cohort Study in 2002 (Cohort 1) and 2014 (Cohort 2), and continued throughout the follow-up period. A basic resident register was referenced to derive the adjusted relative risk estimates for all-cause mortality. Finally, a Cox proportional hazards model analysis was conducted and was adjusted for possible confounders to estimate hazard ratios (HRs). 95% confidence intervals (CIs) were computed separately for male and female participants.

Results

Of the total 3,553 participants, 905 (25.5%) were deceased. Of these, 473 were male (30.1% of all males) and 432 were female (21.8% of all females). Hyperuricemia was defined in males with SUA levels of 8.5 mg/dL or higher, and in females with SUA levels of 7.5 mg/dL or higher, and was associated with a significantly increased HR for all-cause mortality (males: 1.67; 95% CI: 1.06-2.63; females: 2.17; 95% CI: 1.20-3.94). The data were further stratified based on age (< 65 years or ≥ 65 years), body mass index (BMI) (< 25.0 kg/m2 or ≥ 25.0 kg/m2), History of cardiovascular disease, estimated glomerular filtration rate (< 60 mL/min/1.73 m2 or ≥ 60 mL/min/1.73 m2), and presence of SUA-lowering medication. All stratified groups demonstrated a similar trend. The hyperuricemia group in particular reported a significant increase in HR. On the other hand, a U-shaped increase in HR was observed in those with BMI greater than 25 kg/m2 and SUA-lowering medication, but interaction effect was not significant.

Conclusions

Hyperuricemia is a key risk indicator for all-cause mortality in male and female community-dwelling individuals in Japan.

Reference range of serum uric acid and prevalence of hyperuricemia: a cross-sectional study from baseline data of ELSA-Brasil cohort

Background

Most of the few studies that have established reference ranges for serum uric acid (SUA) have not taken into account factors which may interfere with its levels and followed rigorous laboratory quality standards. The aim of this study was to establish reference ranges for SUA and determine the prevalence of hyperuricemia.

Method

Cross-sectional study including 15,100 participants (all sample) aged 35 to 74 years from baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicentric cohort of volunteer civil servants from five universities and one research institute located in different regions of Brazil. It was established a reference sample excluding participants with factors that directly influence SUA levels: glomerular filtration rate lower than 60 ml/min, excessive alcohol intake, use of diuretics, aspirin, estrogen or urate-lowering therapy. SUA was measured using the uricase method and following rigorous international quality standards. Reference ranges were defined as values between percentiles 2.5 (P2.5) and 97.5 (P97.5) of SUA distribution in the reference sample, stratified by sex. Hyperuricemia was defined as SUA ≥ 7 mg/100 ml in the all sample.

Results

The reference sample was composed of 10,340 individuals (55.3% women, median age 50 years). Reference ranges (P2.5 to P97.5) for SUA were: 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Sex was a major determinant for SUA levels (median [IQR], mg/100 ml: 6.1 [5.3–7.0] for men versus 4.5 [3.9–5.3] for women, p < 0.001). Higher levels of SUA were found in patients with higher BMI. Higher age had (a modest) influence only for women. The prevalence of hyperuricemia for all sample (N = 15,100) was 31.9% (95% confidence interval [CI] 30.8–33.0%) in men and 4.8% (95% CI 4.3–5.3%) in women.

Conclusion

SUA reference ranges were 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Prevalence of hyperuricemia was 31.9% in men and 4.8% in women. Updated SUA reference ranges and prevalence of hyperuricemia are higher nowadays and might be used to guide laboratories and the screening for diseases related to SUA.

Managing Cardiovascular Risk in Patients with Rheumatic Disease

Individuals with rheumatoid arthritis, systemic lupus erythematosus, or gout have increased risk of cardiovascular disease (CVD) compared with the general population. This risk relates to a combination of traditional cardiovascular risk factors and disease-specific factors. Screening for CVD is important because CVD contributes to significant morbidity and mortality. Management includes tight control of disease activity to reduce inflammation, but with care to minimize use of nonsteroidal anti-inflammatory drugs and prolonged courses of high-dose corticosteroids. Traditional cardiovascular risk factors should be managed with a combination of lifestyle interventions and pharmacotherapy. The decision to start antihypertensive and lipid-lowering therapy should be based on individual CVD risk.

The Mediation Effect of Body Composition on the Association Between Menopause and Hyperuricemia: Evidence From China National Health Survey

Reproductive factors have been demonstrated to be associated with hyperuricemia. Body composition is an essential determinant influencing serum uric acid (SUA), but it is largely unknown whether increased SUA was influenced by changed body composition during the menopausal transition. As a secondary analysis of China National Health Survey from 2012-to 2017, this study included 18,997 women aged 20 to 80. Menarche age and menopause information were collected by questionnaire interview. Body mass index (BMI), body fat percentage (BFP), fat mass index (FMI), and fat-free mass index (FFMI) were used as body composition indexes. Hyperuricemia was defined as SUA higher than 360μmol/L (approximately 6 mg/dl). Mediation analysis was performed to explore the direct and indirect effects of menopause on hyperuricemia. A 1:2 age-matched case-control data set (n=6202) was designed to control age-related confounders and was used in multivariable analyses. After adjustment of covariates, postmenopausal women had 14.08 (10.89-17.27) μmol/L higher SUA than their premenopausal counterparts. Overweight/obesity and higher levels of BFP, FMI, and FFMI were all found to be positively associated with hyperuricemia. The mediation analysis showed that the total effect of menopause on hyperuricemia was positive, but was substantially mediated by body composition indexes. Forty-five percent of the total effect can be attributed to the indirect effect mediated by BMI (OR for the natural indirect effect (NIE): 1.09, 95%CI: 1.04-1.13), and over 80% mediated by BFP (OR for NIE: 1.23, 95%CI: 1.16-1.29). However, FFMI did not present the mediated role in the association (OR for NIE: 0.99, 95%CI: 0.96-1.02). The findings revealed that body composition, especially the fat mass indexes, significantly mediated the association between menopause and hyperuricemia. The role of body composition as mediator constitutes clinical and public health significance that should be recognized and considered in healthcare for women experiencing their menopause transition.

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.

Uric acid participating in female reproductive disorders: a review

Uric acid (UA) is the end metabolic product of purine metabolism. Early on, UA was considered to be a metabolite with a certain antioxidant capacity. As research has progressed, other properties of UA have been explored, and its association with many diseases has been found. The association between UA and kidney disease and cardiovascular disease is well established; however, there is still a paucity of reviews on the association between UA and the female reproductive system. An increasing number of epidemiological studies have shown elevated serum UA levels in patients with polycystic ovary syndrome (PCOS), endometriosis, etc. Additionally, serum UA can be used as a predictor of pregnancy complications and adverse foetal outcomes. An increasing number of animal experiments and clinical studies have revealed possible mechanisms related to the involvement of UA in certain female reproductive disorders: oxidative stress, chronic inflammation, mitochondrial dysfunction, etc. This article reviews the current mainstream mechanisms regarding the pathogenesis of UA and the role of UA in certain specific female reproductive disorders (direct involvement in the development of certain diseases or enhancement of other risk factors) in the hope of contributing to clinical prevention, diagnosis, treatment and improvement in prognosis.

Managing Cardiovascular Risk in Patients with Rheumatic Disease

Individuals with rheumatoid arthritis, systemic lupus erythematosus, or gout have increased risk of cardiovascular disease (CVD) compared with the general population. This risk relates to a combination of traditional cardiovascular risk factors and disease-specific factors. Screening for CVD is important because CVD contributes to significant morbidity and mortality. Management includes tight control of disease activity to reduce inflammation, but with care to minimize use of nonsteroidal anti-inflammatory drugs and prolonged courses of high-dose corticosteroids. Traditional cardiovascular risk factors should be managed with a combination of lifestyle interventions and pharmacotherapy. The decision to start antihypertensive and lipid-lowering therapy should be based on individual CVD risk.

Food Consumption is Associated with Hyperuricemia in Boys

INTRODUCTION

Hyperuricemia is related to health issues among children and adolescents, once the uric acid concentration is associated with metabolic syndrome, hypertension, insulin resistance, obesity, and dyslipidemia. However, few studies are addressing uric acid levels and food uptake in this age group.

AIM

To verify the association between food consumption and uric acid in children and adolescents.

METHODS

This is a cross-sectional study developed with 2335 children and adolescents of both genders aged 6-17 years old. Blood collection was performed after 12 h of fasting. Uric acid values were classified according to tertiles, in which the highest tertile was considered as hyperuricemia. Food consumption was evaluated by weekly consumption frequency questionnaire. Pearson correlation and logistic binary regressions were used for statistical analysis. Models were adjusted for age, systolic blood pressure, body mass index (BMI), and skin color/ethnicity.

RESULTS

It was found an association between red meat consumption and hyperuricemia only in boys in the crude model (OR = 1.56; 95% CI 1.12; 2.18). Also, there was an association between pasta (OR = 1.52; 95% CI 1.11; 2.10) with hyperuricemia in boys, when adjusted age, systolic blood pressure, BMI, and skin color/ethnicity.

CONCLUSION

The knowledge of food patterns which are predisposing factors for the increase in serum uric acid levels is important for the implementation of strategies and public health policies for health promotion among children and adolescents.

Clinical relevance of serum uric acid and abdominal aortic-calcification in a national survey

Background

Hyperuricemia was often found in subjects with an elevated risk of cardiovascular disease (CVD). Abdominal aortic‐calcification (AAC) is significantly associated with subclinical atherosclerotic disease.

Hypothesis

The aim of this study is to evaluate the relationship between serum uric acid (SUA) level and AAC from a national database.

Methods

A total of 2765 eligible participants older than 40 years who received dual‐energy X‐ray absorptiometry (DXA) scans with SUA data were enrolled from the National Health and Nutrition Examination Survey (2013‐2014). The association between SUA level and AAC was analyzed using multivariate regression models for covariate adjustment.

Results

After categorizing SUA level into four quartiles, the odds ratios for the presence of subclinical atherosclerosis via contrasting the highest SUA quartile with the lowest SUA quartile were 1.876 (95% CI = 1.298‐2.711), 2.038 (95% CI = 1.303‐3.187), 1.935 (95% CI = 1.221‐3.065), and 1.956 (95% CI = 1.225‐3.124) (all, P value less than .05) in Model 1, Model 2, Model 3, and Model 4, respectively. The above relationship remained still in the fully adjusted model for the male but not female subjects. The optimal SUA cutoff value was 6.35 mg/dL for male and 5.25 mg/dL for female to predict the presence of subclinical atherosclerosis.

Conclusions

Our results explore the promising evidences that SUA level showed a positive correlation with AAC score in a dose‐response manner. These findings decisively indicated that SUA may act as a promising tool to forecast the incidence of subclinical atherosclerosis in males.

Uric acid is independent and inversely associated to glomerular filtration rate in young adult Brazilian individuals

BACKGROUND AND AIMS

Uric acid, the end-product of human purine metabolism, is associated with hypertension, diabetes and obesity. It has also been independently associated with the onset of chronic kidney disease in several populations. In this study, the association between serum uric acid (SUA) level and estimated glomerular filtration rate (eGFR) was investigated in healthy individuals belonging to two Brazilian birth cohorts.

METHODS AND RESULTS

Data from 3541 to 3482 individuals, aged 30 and 22-years old, respectively, was included. eGFR was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine measurement. Regression analyses were sex-stratified due to interaction between SUA and sex (p < 0.001) and adjusted for perinatal, cardiometabolic and behavioral variables. We observed an inverse association between eGFR and SUA even after adjustment. In the highest tertile (3rd) of SUA, the eGFR coefficients at 30-years were-0.21 (95%CI -0.24;-0.18) for men and -0.20 (95%CI -0.23; -0.17) for women; at 22-years, were -0.09 (95%CI -0.12;-0.05) for men and -0.13 (95%CI -0.15; -0.10) for women. Higher differences among exponential means (95% CI) of eGFR between the 1st and the 3rd tertile of SUA were seen in older participants, being more pronounced in men. At 22-years, the highest difference was found in women.

CONCLUSIONS

In young healthy individuals from a low-middle income country, SUA level was inversely associated with eGFR. Gender-related differences in eGFR according tertiles of SUA were higher in men at 30-years and in women at 22-years.

Hyperuricaemia and its association with 10-year risk of cardiovascular disease among migrant and non-migrant African populations: the RODAM study

OBJECTIVE

In the advent of rapid urbanisation, migration and epidemiological transition, the extent to which serum uric acid (sUA) affects cardiovascular disease (CVD) risk among Africans is not well understood. We assessed differences in sUA levels and associations with CVD risk among migrant Ghanaians in Europe and non-migrant Ghanaians in rural and urban Ghana.

METHODS

Baseline data from 633 rural, 916 urban and 2315 migrant participants (40-70 years) from the cross-sectional RODAM study were analysed. Hyperuricaemia was defined as sUA >7 mg/dl in men and >6 mg/dl in women. The 10-year risk of atherosclerotic cardiovascular disease (ASCVD) was calculated using the American College of Cardiology (ACC)/American Heart Association (AHA) risk score which takes into account ethnic minority populations. High CVD risk was defined as ASCVD risk scores ≥7.5%. Logistic regressions were used to assess associations between hyperuricaemia and CVD risk.

RESULTS

Prevalence for hyperuricaemia in rural, urban and migrant participants was 17.4%, 19.1% and 31.7% for men, and 15.9%, 18.2% and 33.2% for women, respectively. Hyperuricaemia was positively associated with elevated CVD risk among rural residents (adjusted OR for men 3.28, 95% CI: 1.21-8.96, 6.36, 95% CI: 2.98-13.56 for women), urban residents (1.12, 95% CI: 0.45-2.81 for men, 2.11, 95% CI: 1.26-3.52 for women) and migrants (1.73, 95% CI: 1.01-2.96 for men, 4.61, 95% CI: 3.05-6.97 for women).

CONCLUSION

Our study shows variations of sUA levels in different African contexts. Hyperuricaemia is associated with elevated 10-year CVD risk in both migrants and non-migrants. Further studies should identify factors driving associations between sUA and CVD risk in Africans.

Association of the ESR1 polymorphism with menopause and MLXIPL genetic variant influence serum uric acid levels in Slovak midlife women

OBJECTIVE

This study examines associations between the ESR1 (XbaI, PvuII) and the MLXIPL (rs3812316) gene polymorphisms, and uric acid (UA) levels in Slovak midlife women, subdivided according to their menopause status.

METHODS

We assessed a total of 362 women from 38 to 65 years of age. Women were recruited from different localities in the western and middle parts of Slovakia. Participants were interviewed during their medical examination at local health centers. They were investigated with respect to a variety of aspects such as medical, anthropometrical, and lifestyle. Participants provided a blood sample for biochemical analyses and DNA genotyping. The MLXIPL gene (rs3812316 SNP variant) and ESR1 gene (PvuII and XbaI) genotypes were then detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Data were analyzed using general linear models and multiple linear regression analyses to adjust for risk factors elevating the UA level such as fat mass (FM), triglycerides (TGs) and creatinine.

RESULTS

A positive association between MLXIPL and UA level was observed in the total sample of women after control for confounding covariates, including FM, TGs, and creatinine (P = 0.027). Women with the CC genotype had higher UA levels than the G-allele carriers (261.5 μmol/L ± 68.3 vs 241.1 μmol/L ± 55.1 P = 0.013). A statistically significant association was noticed between postmenopause status and the ESR1 XbaI genotype and their effect on UA (P = 0.028). The Bonferroni pairwise comparison determined that the G-allele carriers in the postmenopausal period had higher estimated UA marginal mean (269.7 μmol/L) than the AA-allele postmenopausal women (236.5 μmol/L) (P = 0.012). The estimated UA marginal mean showed a significant increasing trend according to the MS in G allele carriers (248.5 μmol/L in pre/peri-menopausal vs 269.7 μmol/L in postmenopausal, P = 0.009). In contrast, a decreasing trend was observed in AA carriers (250.6 μmol/L in pre/perimenopausal women vs 236.5 μmol/L in postmenopausal). However, this trend was not statistically significant (P = 0.288).

CONCLUSIONS

This cross-sectional study suggests that MLXIPL (rs3812316) polymorphism is associated with higher serum UA levels and that the ESR1 (XbaI) polymorphism is associated with UA levels only in the postmenopausal cohort.

The Prevalence of Hyperuricemia Sharply Increases from the Late Menopausal Transition Stage in Middle-Aged Women

The impact of menopausal transition on change of serum uric acid level remains unknown. The present study evaluated the relationship of menopausal stages with prevalent hyperuricemia in middle-aged women. This cross-sectional study included 58,870 middle-aged Korean women, aged ≥40, who participated in a health examination from 2014 to 2016. Menopausal stages were obtained with a standardized, self-administered questionnaire and were categorized according to the criteria of the Stages of Reproductive Aging Workshop (STRAW+10). Hyperuricemia was defined as a serum uric acid level of ≥6 mg/dL. The prevalence of hyperuricemia increased as menopausal stage increased. The multivariable-adjusted odds ratios (95% confidence intervals) for prevalent hyperuricemia comparing early transition, late transition, and post-menopause to pre-menopause were 1.19 (0.80–1.77), 2.13 (1.35–3.36), and 1.65 (1.33–2.04), respectively. This association was stronger among non-obese compared to obese participants and in those with low high-sensitivity C-reactive protein (hsCRP) levels (<1.0 mg/L) compared to those with elevated hsCRP levels of ≥1.0 mg/L (p for interaction = 0.01). In this large sample of middle-aged women, the prevalence of hyperuricemia significantly increased from the menopausal stage of late transition, independent of potential confounders. Appropriate preventive strategies for reducing hyperuricemia and its related consequences should be initiated prior to menopause.

Association of hyperuricemia with metabolic syndrome among university workers: sex and occupational differences

BACKGROUND

The relationship between metabolic syndrome (MetS) and hyperuricemia is not fully understood.

OBJECTIVE

To examine the association of hyperuricemia with MetS and the component of MetS that is mostly influenced by hyperuricemia among university workers.

METHODS

Anthropometric measurements, blood pressure, glucose, lipid profiles, renal function tests were measured in 1198 male and 1075 female (22-60 years old) workers on annual medical examination.

RESULTS

Hyperuricemia was 3-fold higher in males (odds ratio, OR, 2.938, 95% confidence interval, CI, 1.909-4.522, P<0.01) than females after adjustment for age, body mass index (BMI) and renal function. Overall, individuals with hyperuricemia were 3.9-fold likely to have MetS OR, 3.903; CI (2.439-6.245), P<0.01, and dyslipidemia, 2.5 times (OR, 2.501; 95% CI, 1.776-3.521, P<0.01) after adjustment for age, BMI, sex and renal function. However, no associations were found in individuals with hypertension (OR, 1.427; 95% CI, 0.996-2.205, P=0.052) and hyperglycemia (OR, 1.476; 95% CI, 0.989-2.202, P=0.057). Administrative work positively associated (OR, 1.895; 95% CI, 1.202-2.925, P<0.05) with hyperuricemia in males and not females.

CONCLUSION

Male workers with hyperuricemia, especially those working in administration were at risk of metabolic syndrome. It is important to screen, prevent and treat metabolic syndrome in individuals diagnosed with hyperuricemia at the workplace.

Metabolic syndrome and the decreased levels of uric acid by leflunomide favor redox imbalance in patients with rheumatoid arthritis

Oxidative stress plays a role in the pathophysiology of rheumatoid arthritis (RA). The aim of the present study was to verify the influence of metabolic syndrome (MetS) and disease-modifying antirheumatic drugs on nitrosative and oxidative biomarkers in patients with RA. A total of 177 patients with RA and 150 healthy volunteers participated in this study, which measured lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), carbonyl protein, total radical-trapping antioxidant parameter (TRAP), uric acid (UA), and C-reactive protein (CRP). NOx and the NOx/TRAP ratio were significantly increased in RA, while no significant differences in lipid hydroperoxides, AOPP, UA, and TRAP levels were found between both groups. Treatment with leflunomide was associated with increased levels of carbonyl protein, and lowered levels in TRAP and UA, while the NOx/TRAP ratio further increased. NOx and the NOx/TRAP ratio were significantly higher in women than in men, while TRAP and UA were significantly lower in women. MetS was accompanied by increased AOPP and UA levels. RA was best predicted by increased NOx/TRAP ratio, CRP, and BMI. In conclusion, our data demonstrated that NOx and NOx/TRAP are strongly associated with RA physiopathology. Our findings suggest that inhibition of iNOS may become an interesting therapeutic approach for the treatment of RA. In addition, the presence of MetS and a decrease in levels of UA by leflunomide favor redox imbalance in RA patients. More studies are needed to evaluate the impact of antioxidant capacity reduction on RA progression.

Prevalence and risk factors of hyperuricemia: results of the Kailuan cohort study

OBJECTIVE

The objective of this study is to determine the serum uric acid (SUA) level and the prevalence of hyperuricemia (HUA) in Chinese population.

METHODS

We conducted a cross-sectional study among 100,226 employees (79.9% male) of the Kailuan Group using physical examination data in 2006-2007. HUA was defined as SUA >356.9 μmol/L (6.0 mg/dL) for women and SUA >416.4 μmol/L (7.0 mg/dL) for men. We investigated crude and age adjusted HUA prevalence and compared characteristics of subjects with and without HUA in men and women using multivariate logistic regression.

RESULTS

SUA levels were 244.9 ± 71.5 μmol/L in women and 302.0 ± 83.5 μmol/L in men. About 8290 (8.27%) subjects were diagnosed with HUA. Age-adjusted prevalence of HUA was 8.02% in the total sample (6.87% in women and 8.57% in men). The SUA level and HUA prevalence showed U-shaped or J-shaped associations with age. Multivariate logistic regression revealed age, waist circumference, total cholesterol, triglyceride, hypertension and non-alcoholic fatty liver disease history, prolonged sitting, alcohol consumption, and oral diuretics were independent risk factors of HUA, while long sleep duration was protective against HUA.

CONCLUSIONS

The prevalence of HUA is 6.87% and 8.57% in Chinese women and men. HUA is likely related with life style and metabolic disorders.

Association between Sex Hormone and Blood Uric Acid in Male Patients with Type 2 Diabetes

The association between serum uric acid (SUA) level and sexual dysfunction in patients with diabetes is not well characterized. Type 2 diabetes mellitus (T2DM) causes metabolic disorders, including abnormal serum uric acid (SUA) levels. In this study, we enrolled 205 male patients with T2DM and investigated the relationship between sex hormone levels and SUA. Patients were divided into four groups based on SUA quartiles. On the other hand, based on the total testosterone (TT) level, patients were divided into three groups; SUA and other laboratory indices were determined. Increase in SUA level was significantly associated with decreased levels of TT, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, and increased levels of dehydroepiandrosterone, age, body mass index (BMI), waist circumference, glycated hemoglobin, serum creatinine, and HOMA-IR levels. SUA, waist circumference, BMI, and HOMA-IR showed a negative correlation with TT level, while age showed a positive correlation with TT level. SUA and body mass index were found to be risk factors for gonadal dysfunction. Therefore, we conclude that hypogonadism of male patients with T2DM is related to SUA level.

High uric acid level predicts left atrial thrombus or spontaneous echo contrast detected by transesophageal echocardiography: Meta-analysis and systematic review

Background

Recent observational studies have suggested that the patients with hyperuricemia have a higher risk of having left atrial thrombus (LATH) or left atrial spontaneous echo contrast (LASEC) by transesophageal echocardiography (TEE), while the ultimate predictive value of a high uric acid (UA) level on LATH/LASEC remained obscure.

Methods

We searched the PubMed and Cochrane clinical trials databases up to July 2015. Following screening the 369 initially identified studies, we analyzed six observational studies with 2381 patients.

Results

The meta-analysis of these studies showed that an elevated serum UA level was associated with a higher likelihood of LATH/LASEC (OR = 1.59, 95%CI 1.13–2.23, P = 0.008), while significant differences exist among individual trials (P < 0.00001 and I² = 85%). Sensitivity analysis failed to find any heterogeneity.

Conclusion

An elevated UA level was associated with a higher risk of detecting a left atrial abnormality represented by LATH/LASEC.

Effects of coffee consumption on serum uric acid: systematic review and meta-analysis

OBJECTIVE

Study results on the effects of coffee consumption on serum uric acid (UA) have been conflicting. The aim of this study is to analyze the literature regarding the effect of coffee consumption on serum UA.

METHODS

We searched MEDLINE, EMBASE, the Cochrane library, and KoreaMed for all articles published before January 2015. Studies with quantitative data on coffee consumption and serum UA level were included. Coffee consumption and serum UA level were identified with/without the risk of gout.

RESULTS

Nine studies published between 1999 and 2014 were included, containing a total of 175,310 subjects. Meta-analysis demonstrated that coffee has a significantly lowering effect on serum UA, where there are gender differences in the amount of coffee required to lower serum UA. Women (4-6 cups/day) need more coffee to lower serum UA than men (1-3 cups/day). Meta-analysis showed that coffee intake of 1 cup/day or more was significantly associated with reduction of the risk of gout, with a negative correlation with the amount of daily coffee intake for both genders.

CONCLUSIONS

This is the first systematic review on the effects of coffee consumption on serum UA. Based on our study, moderate coffee intake might be advocated for primary prevention of hyperuricemia and gout in both genders.

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.

Association of uric acid with traditional inflammatory factors in stroke

Uric acid (UA) plays an important role in the oxidant stress that causes inflammation. We assessed the association between UA and neutrophil ratio, white blood cell (WBC) count and blood lipid in 524 patients admitted with stroke. Stroke patients with a neutrophil ratio >70% displayed significantly lower UA levels than those with a neutrophil ratio ≤70% (p < 0.05). According to UA quartiles, neutrophil ratio, WBC count, and high-density lipoprotein cholesterol in the UA grade 1 group (≤214.10 μmol/L) were significantly increased over those in other UA grade groups. The results of stepwise regression analysis found that UA levels were inversely associated with neutrophil ratios (B ± SE = -1.11 ± 0.35), high-density lipoprotein cholesterol (B ± SE = -46.18 ± 14.17), total cholesterol (B ± SE = 9.82 ± 3.66), blood urea nitrogen (B ± SE = 6.30 ± 1.73), and creatinine (B ± SE = 0.63 ± 0.10). There is a correlationship between lower serum uric acid with neutrophil ratios in inflammation associated with stroke and the reasons need to be investigated further.

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.

Association between serum uric acid and lumbar spine bone mineral density in peri- and postmenopausal Japanese women

SUMMARY

Previous studies on the association between uric acid and bone mineral density yielded conflicting results. In this study, we demonstrated positive association between uric acid and lumbar spine bone mineral density in peri- and postmenopausal Japanese women. Further research is needed to elucidate the underlying mechanism.

INTRODUCTION

Oxidative stress has been implicated in the pathogenesis of osteoporosis. Uric acid, a potent antioxidant substance, has been associated with bone mineral density but previous studies have yielded conflicting results. The objective of the study was to examine the association between serum uric acid and lumbar spine bone mineral density (BMD).

METHODS

This was a retrospective analysis of medical records of 615 women, aged 45-75 years, who had lumbar spine BMD measurement by dual-energy X-ray absorptiometry as a part of health checkup from August 2011 to July 2012.

RESULTS

Mean serum uric acid level was 4.7 mg/dL. Serum uric acid level was positively and significantly associated with lumbar spine BMD independent of age, body mass index, smoking, drinking, physical activity, years after menopause, diabetes mellitus, hypertension, serum calcium, estimated glomerular filtration rate, plasma C-reactive protein, and serum alkaline phosphatase (standardized beta = 0.078, p = 0.049). Uric acid rapidly increased until the age of 60 years, and then decelerated but continued to increase thereafter. The association between lumbar spine BMD and uric acid remained significantly positive after excluding women older than 60 years.

CONCLUSION

The present study showed that higher uric acid levels were linearly associated with higher lumbar spine BMD in peri- and postmenopausal Japanese women. Further research is needed to elucidate the underlying mechanism of the association between uric acid and BMD.

Risk factors for incident hyperuricemia during mid-adulthood in African American and white men and women enrolled in the ARIC cohort study

Background

Increased serum urate levels are associated with poor outcomes including but not limited to gout. It is unclear whether serum urate levels are the sole predictor of incident hyperuricemia or whether demographic and clinical risk factors also predict the development of hyperuricemia. The goal of this study was to identify risk factors for incident hyperuricemia over 9 years in a population-based study, ARIC.

Methods

ARIC recruited individuals from 4 US communities; 8,342 participants who had urate levels <7.0 mg/dL were included in this analysis. Risk factors (including baseline, 3-year, and change in urate level over 3 years) for 9-year incident hyperuricemia (urate level of >7.0 g/dL) were identified using an AIC-based selection approach in a modified Poisson regression model.

Results

The 9-year cumulative incidence of hyperuricemia was 4%; men = 5%; women = 3%; African Americans = 6% and whites = 3%. The adjusted model included 9 predictors for incident hyperuricemia over 9 years: male sex (RR = 1.73 95% CI: 1.36-2.21), African-American race (RR = 1.79 95% CI: 1.37-2.33), smoking (RR = 1.27, 95% CI: 0.97-1.67), <HS education (RR = 1.27, 95% CI: 0.99-1.63), hypertension (RR = 1.65, 95% CI: 1.30-2.09), CHD (RR = 1.57, 95% CI: 0.99-2.50), obesity (class I RR = 2.37, 95% CI: 1.65-3.41 and ≥ class II RR = 3.47, 95% CI: 2.33-5.18), eGFR < 60 (RR = 2.85, 95% CI: 1.62-5.01) and triglycerides (Quartile 4 vs. Quartile 1: RR = 2.00, 95% CI: 1.38-2.89). In separate models, urate levels at baseline (RR 1 mg/dL increase = 2.33, 95% CI: 1.94-2.80) and 3 years after baseline (RR for a 1 mg/dL increase = 1.92, 95% CI: 1.78-2.07) were associated with incident hyperuricemia after accounting for demographic and clinical risk factors.

Conclusion

Demographic and clinical risk factors that are routinely collected as part of regular medical care are jointly associated with the development of hyperuricemia.

Synergistic influence of age and serum uric acid on blood pressure among community-dwelling Japanese women

Serum uric acid (SUA) levels are strongly correlated with aging, gender, renal function, obesity, and metabolic abnormality; however, whether SUA has a causative role in elevated blood pressure (BP) is still a matter of debate. From a single community, we recruited 1177 eligible women (mean age, 61±13 years) during their annual health examination. All subjects were divided into two groups according to their age (participants aged ≥55 years and those aged <55 years). We investigated whether age and SUA are synergistically associated with BP, independent of confounding factors. Of these subjects, SUA significantly correlated with both systolic BP (SBP; r=0.236, P<0.001) and diastolic BP (DBP; r=0.263, P<0.001) in female participants aged <55 years but not in those aged ≥55 years. The interaction between age and SUA on BP as well as age and body mass index, triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, prevalence of antidiabetic medication and SUA was a significant and independent determinant of both SBP (β=-0.106, P=0.011) and DBP (β=-0.070, P=0.003). In participants aged <55 years, the multivariate-adjusted odds ratio (95% confidence interval) for hypertension was 3.03 (1.13-8.11) for the highest tertile (4.8-10.8 mg dl(-1)) of SUA compared with the lowest tertile (0.7-3.8 mg dl(-1)) but was not significant in those aged ≥55 years. These results suggested that age and SUA have a synergistic effect on BP status in community-dwelling women, independent of conventional cardiovascular risk factors.

Serum uric acid concentrations in meat eaters, fish eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort

INTRODUCTION

Circulating concentrations of uric acid may be affected by dietary components such as meat, fish and dairy products, but only a few studies have compared uric acid concentrations among individuals who exclude some or all of these foods from their diet. The aim of this study was to investigate differences in serum uric acid concentrations between meat eaters, fish eaters, vegetarians and vegans.

SUBJECTS AND METHODS

A sample of 670 men and 1,023 women (424 meat eaters, 425 fish eaters, 422 vegetarians and 422 vegans, matched on age and sex) from the European Prospective Investigation into Cancer and Nutrition Oxford cohort were included in this cross-sectional analysis. Diet was assessed using a semi-quantitative food frequency questionnaire and serum concentrations of uric acid were measured. Mean concentrations of uric acid by diet group were calculated after adjusting for age, body mass index, calcium and alcohol intake.

RESULTS

In both men and women, serum uric acid concentrations differed significantly by diet group (p<0.0001 and p = 0.01, respectively). The differences between diet groups were most pronounced in men; vegans had the highest concentration (340, 95% confidence interval 329-351 µmol/l), followed by meat eaters (315, 306-324 µmol/l), fish eaters (309, 300-318 µmol/l) and vegetarians (303, 294-312 µmol/l). In women, serum uric acid concentrations were slightly higher in vegans (241, 234-247 µmol/l) than in meat eaters (237, 231-242 µmol/l) and lower in vegetarians (230, 224-236 µmol/l) and fish eaters (227, 221-233 µmol/l).

CONCLUSION

Individuals consuming a vegan diet had the highest serum concentrations of uric acid compared to meat eaters, fish eaters and vegetarians, especially in men. Vegetarians and individuals who eat fish but not meat had the lowest concentrations of serum uric acid.