Correlation of asymptomatic hyperuricaemia and serum uric acid levels with arterial stiffness in women with systemic lupus erythematosus without clinically evident atherosclerotic cardiovascular disease

Low expression of estrogen receptor β in renal tubular epithelial cells may cause hyperuricemia in premenopausal patients with systemic lupus erythematosus

We investigated the impact of estrogen receptor (ER) expression in renal tubular epithelial cells on serum uric acid (UA) levels in premenopausal patients with systemic lupus erythematosus (SLE). Thirty patients underwent renal biopsy: 18 with SLE (LN group) and 12 with IgA nephritis (IgAN group). ERs (ERα and ERβ) in renal tubular epithelial cells were measured using immunohistochemistry. The ER expression levels of the two groups were compared, and the relationship between the expression of ERs and serum UA levels was analyzed. Mean serum UA levels in the LN group were significantly higher than those of the IgA nephropathy group, while the mean creatinine levels and GFRs of the two groups were similar. Pathological changes in the LN group were significantly more severe than those in the IgAN group. ERβ was expressed in renal tubular epithelial cells in both groups, but not in the glomeruli. ERβ expression in the LN group was significantly lower than that in the IgAN group. ERβ expression scores significantly negatively correlated with serum UA levels. These findings suggest that the expression of ERβ in premenopausal female SLE patients may cause hyperuricemia, and may subsequently promote glomerular damage, suggesting that ERβ may be involved in UA excretion.

The association between metabolic syndrome and its components with systemic lupus erythematosus: a comprehensive systematic review and meta-analysis of observational studies

OBJECTIVES

Based upon inflammatory-related factors in chronic systemic lupus erythematosus (SLE), as well as the long-term prescription of corticosteroids, metabolic syndrome (MetS) prevalence is expected to be higher in SLE patients than among those without SLE. The aim of this study was to systematically analyze: (1) the worldwide prevalence of MetS in patients with SLE using different criteria, (2) the risk of MetS in patients with SLE compared with those without SLE, and (3) the risk of MetS component in patients with SLE compared with healthy controls.

METHODS

We searched international databases, such as: Web of Science, Medline, PubMed, Scopus, Embase, CABI, CINAHL, DOAJ and Google Scholar. The articles which reported the prevalence of MetS in SLE patients, between 2006 and 2017, were included in the study if they had a: clear study design, study time and location, sound sampling approach and appropriate statistical analyses. Studies without sufficient data to determine the prevalence of MetS were excluded. Also, studies in patients suffering from other clinical diseases were not included.

RESULTS

The meta-analyses of the prevalence (40 studies (n = 6085)) and risk (20 studies (n = 2348)) of MetS in SLE patients were conducted separately. The pooled prevalence of MetS among SLE patients was found to be 26% (95% confidence interval (CI): 22-30%), but varied from 18% (95% CI: 11-25%) to 34% (95% CI: 25-42%), depending upon the diagnostic criteria used. The overall pooled odds ratio (OR) of MetS in SLE patients, compared with healthy controls, was (OR = 2.50; 95% CI: 1.86-3.35), but this ranged from (OR = 1.23; 95% CI: 0.61-2.49) to (OR = 10.71; 95% CI: 1.33-86.48), depending upon the criteria used. Also, the risk of high fasting blood sugar (FBS; OR = 1.59; 95% CI: 1.05-2.40), low high-density lipoprotein cholesterol (HDL-C; OR = 1.43; 95% CI: 1.02-2.01), high blood pressure (BP; OR = 2.76; 95% CI: 2.19-3.47), high triglycerides (TG; OR = 2.85; 95% CI: 2.05-3.95) and high waist circumference (WC; OR = 1.37; 95% CI: 0.97-1.94) were all found to be higher in SLE patients compared with healthy controls.

CONCLUSIONS

The risk of MetS was significantly higher in SLE patients, compared with healthy controls, even after adjusting for publication bias. Among MetS components, high TG and high BP were most strongly associated with SLE. Considering that high TG and high BP are preventable, there is an international need to implement effective interventions to reduce MetS components in SLE patients in order to prevent serious outcomes such as cardiovascular diseases and mortality.

The prevalence, subtypes and associated factors of hyperuricemia in lupus nephritis patients at chronic kidney disease stages 1-3

There is a high prevalence of hyperuricemia (HUA) in the chronic kidney disease (CKD) population. However, there's a dearth of research on HUA's prevalence, subtypes, early detection, and treatment strategies of HUA in lupus nephritis (LN) patients. The aim of this study is to address these knowledge gaps. LN patients presenting to the Department of Nephrology at Shanghai Rui Jin Hospital from January 2011 to January 2016 were recruited. The effective sample size was derived using the power analysis. The demographic, clinical and laboratory characteristics of the LN patients with HUA were compared with those of patients without HUA. Two statistical models for analyzing HUA were built and compared using the receiver operating characteristic (ROC) curve analysis. The total prevalence of HUA in the cohort was 40.11%. The subtypes of HUA included urate underexcretion-type, overproduction-type and combined-type, which proportion being 67.7%, 9.7% and 22.6% respectively. The CKD stage was closely associated with the prevalence of HUA in patients with LN. The other significant associated factors were hypertension, triglycerides, serum creatinine, serum albumin, hemoglobin, parathyroid hormone, phosphorus, calcium, etc. The statistical algorithm successfully identified LN patients at risk of HUA. In conclusion, there was a high prevalence of HUA in LN patients at CKD stages 1-3, and renal underexcretion hyperuricemia was the most prevalent subtype. The occurrence of HUA in LN may be related to renal insufficiency, metabolic disorder and lupus itself. Early care coordination programs can employ risk models to improve HUA prevention and target interventions in LN patients.

Serum uric acid concentration is associated with hypertensive retinopathy in hypertensive chinese adults

BACKGROUND

This cross sectional investigation included 12,966 subjects with hypertension, a cohort of the China Stroke Primary Prevention Trial (CSPPT), a randomized, multicenter clinical trial. This study aimed to explore the correlation between serum uric acid (SUA) concentration and hypertensive retinopathy in hypertensive adults.

METHODS

Diagnosis of hypertensive retinopathy was determined by non-mydriatic fundus photography and classified with Keith-Wagener-Barker (KWB) system. The correlation of SUA levels with hypertensive retinopathy prevalence and severity was assessed by statistical analysis.

RESULTS

9848 (75.95%) subjects were diagnosed with hypertensive retinopathy with the following retinopathy grade distribution: grade 1: 58.80%, grade 2: 14.81%, and grade 3-4: 2.34%. SUA levels were significantly associated with hypertensive retinopathy prevalence. Patients with hypertensive retinopathy had higher SUA levels than those without hypertensive retinopathy. Patients in the highest uric acid quartile had an odds ratio for hypertensive retinopathy of 1.21 compared to patients in the lowest uric acid quartile (OR = 1.21, 95% CI: 1.05-1.40, P = 0.008). When compared to the non-hyperuricemia group, those in the hyperuricemia group had an odds ratio for hypertensive retinopathy of 1.18(OR = 1.18, 95% CI: 1.05-1.33, P = 0.004). Every 1 mg/dl increase in uric acid concentration was significantly associated with a 6% higher odds of hypertensive retinopathy (OR = 1.06, 95% CI: 1.02-1.10, P = 0.002).

CONCLUSIONS

The prevalence of hypertensive retinopathy was high (75.95%) among hypertensives in our patients cohort. In addition, SUA concentration was significantly associated with hypertensive retinopathy.

Peripheral arterial stiffness is associated with higher baseline plasma uric acid: A prospective cohort study

This prospective cohort study aimed at identifying association between uric acid (UA) and peripheral arterial stiffness. A prospective cohort longitudinal study was performed according to an average of 4.8 years’ follow-up. The demographic data, anthropometric parameters, peripheral arterial stiffness (carotid-radial pulse-wave velocity, cr-PWV) and biomarker variables including UA were examined at both baseline and follow-up. Pearson’s correlations were used to identify the associations between UA and peripheral arterial stiffness. Further logistic regressions were employed to determine the associations between UA and arterial stiffness. At the end of follow-up, 1447 subjects were included in the analyses. At baseline, cr-PWV (r = 0.200, p < 0.001) was closely associated with UA. Furthermore, the follow-up cr-PWV (r = 0.145, p < 0.001) was also strongly correlated to baseline UA in Pearson’s correlation analysis. Multiple regressions also indicated the association between follow-up cr-PWV (β = 0.493, p = 0.013) and baseline UA level. Logistic regressions revealed that higher baseline UA level was an independent predictor of arterial stiffness severity assessed by cr-PWV at follow-up cross-section. Peripheral arterial stiffness is closely associated with higher baseline UA level. Furthermore, a higher baseline UA level is an independent risk factor and predictor for peripheral arterial stiffness.

Uric Acid, Vascular Stiffness, and Chronic Kidney Disease: Is There a Link?

Controversy exists with regard to the causal role of hyperuricemia in chronic kidney disease. Vascular stiffness may be the link that explains the relation between hyperuricemia and kidney disease. Hyperuricemia is associated with a number of effects on the vascular endothelium and vascular smooth muscle cells, including an increase in oxidative stress, production of vasoconstrictors, and changes on the structural properties of the large artery wall. Observational evidence in large epidemiological cross-sectional studies suggests that there is an independent association between uric acid and arterial stiffness. The limited evidence from cohort studies or clinical trials does not support treatment of hyperuricemia to reduce vascular stiffness in order to prevent kidney disease. Nevertheless, vascular stiffness may be a valid, reproducible, and useful surrogate endpoint. At this point there seems to be sufficient evidence to warrant larger clinical trials to determine whether lowering uric acid concentrations would be useful for prevention or treatment of vascular stiffness and, subsequently, of cardiovascular and kidney diseases. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=452726.

Why are kids with lupus at an increased risk of cardiovascular disease?

Juvenile-onset systemic lupus erythematosus (SLE) is an aggressive multisystem autoimmune disease. Despite improvements in outcomes for adult patients, children with SLE continue to have a lower life expectancy than adults with SLE, with more aggressive disease, a higher incidence of lupus nephritis and there is an emerging awareness of their increased risk of cardiovascular disease (CVD). In this review, we discuss the evidence for an increased risk of CVD in SLE, its pathogenesis, and the clinical approach to its management.

The vascular phenotype of children with systemic lupus erythematosus

BACKGROUND

The increased risk of cardiovascular disease (CVD) in adults with systemic lupus erythematosus (SLE) has been known since the 1970s, but studies in juvenile-onset SLE (JSLE) have reported conflicting results and more data are needed. The aim of this cross-sectional study was to establish the baseline risk of CVD in a cohort of UK patients with JSLE.

METHODS

Data were collected to establish disease duration, disease activity, medication use and activity levels, as well as demographic data, including family history of CVD. Vascular phenotype was established using well-validated measures of carotid intima media thickness (cIMT) and pulse wave velocity (PWV).

RESULTS

In total, 45 children (39 female; mean age 13.5 ± 2.9 years) with JSLE were recruited to the study. Of these, 24 had a history of biopsy-proven lupus nephritis and five had an estimated glomerular filtration rate of <90 ml/min/1.73 m(2). Comparison of these JSLE patients with healthy controls previously scanned at our hospital revealed that the cIMT value was significantly higher in the former (0.45 vs. 0.37 mm, respectively; p < 0.0001). This difference was associated with the use of antihypertensives (p = 0.04) and higher or lower doses of prednisolone (p < 0.0001). PWV was not significantly different in the patient and control group (5.27 vs. 5.34 m/s, respectively; p = 0.77). In the patient group, the mean body mass index percentile was 65.63 ± 28.8, and the median physical activity score was 1,773 (676-2,854) metabolic equivalents of task (METs). None of the patients admitted to cigarette smoking, and ten had a positive family history of cardiovascular disease (CVD).

CONCLUSION

This study shows that our patients with JSLE had increased cIMT without an increase in PWV, suggesting possible early adaptive changes in JSLE. Follow-up data are needed to determine whether these changes result in clinically significant CVD.

Hydroxychloroquine and pregnancy on lupus flares in Korean patients with systemic lupus erythematosus

We investigated the clinical and laboratory characteristics of pregnancies with systemic lupus erythematosus (SLE) and identified lupus flare predictors during pregnancy. Additionally, we examined lupus activity and pregnancy outcomes in SLE patients who continued, discontinued or underwent no hydroxychloroquine (HCQ) treatment during pregnancy. We retrospectively analyzed 179 pregnancies in 128 SLE patients at Seoul St. Mary’s Hospital, Korea, between 1998 and 2012 and then assessed the clinical profiles and maternal and fetal outcomes. Overall, 90.5% of pregnancies resulted in a successful delivery and were divided into two groups: those who experienced lupus flares (80 pregnancies, 44.7%) and those who did not (99 pregnancies, 55.3%). Increased preeclampsia, preterm births, low birth weight, intrauterine growth restriction (IUGR), and low 1-minute Apgar scores occurred in pregnancies with lupus flares compared to pregnancies in quiescent disease. Lupus flares were predicted by HCQ discontinuation, a history of lupus nephritis, high pre-pregnancy serum uric acid and low C4 levels. Our study indicates that achieving pre-pregnancy remission and continuing HCQ treatment during pregnancy are important for preventing lupus flares.

Review of hyperuricemia as new marker for metabolic syndrome

Hyperuricemia has long been established as the major etiologic factor in gout. In recent years, a large body of evidence has accumulated that suggests that hyperuricemia may play a role in the development and pathogenesis of a number of metabolic, hemodynamic, and systemic pathologic diseases, including metabolic syndrome, hypertension, stroke, and atherosclerosis. A number of epidemiologic studies have linked hyperuricemia with each of these disorders. In some studies, therapies that lower uric acid may prevent or improve certain components of the metabolic syndrome. There is an association between uric acid and the development of systemic lupus erythematosus; the connection between other rheumatic diseases such as rheumatoid arthritis and osteoarthritis is less clear. The mechanism for the role of uric acid in disorders other than gout is not well established but recent investigations point towards systemic inflammation induced by urate, as the major pathophysiological event common to systemic diseases, including atherosclerosis.

Effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease

It is still uncertain whether total bilirubin per se is a risk factor for osteoporosis in postmenopausal women and no study has so far examined this important issue. This study was designed to assess the sheer effects of total bilirubin on the prevalence of osteoporosis in postmenopausal women without potential liver disease. In the present study, postmenopausal female subjects without potential liver disease (n = 918) who underwent measurement of bone mineral density were enrolled. Correlation and logistic regression analysis were used to assess the relationship between total bilirubin and other variables. As a result, subjects with osteoporosis had a significantly lower total bilirubin level (P = 0.005). A 0.1 mg/dl increase in total bilirubin was associated with reduced odds ratio of the risk by 38 % for osteoporosis [OR 0.62 (95 % CI 0.52-0.88), P = 0.012] after adjustment for several variables. Total bilirubin was independently associated with BMD [coefficient = 0.41, 95 % CI (0.35-0.47), P < 0.001 for lumbar spine and coefficient = 0.44, 95 % CI (0.36-0.48), P < 0.001 for femur neck]. A positive correlation could be observed with significant difference between total bilirubin and z-score (r = 0.33, P < 0.001 for lumbar spine and r = 0.37, P < 0.001 for femur neck) and total bilirubin was positively correlated with serum calcium (r = 0.13, P < 0.001) as well. Therefore, this study demonstrates an independent inverse association between total bilirubin and the prevalence of osteoporosis in postmenopausal women without potential liver disease. Total bilirubin would be useful as a provisional new risk factor of osteoporosis in such a population.

Increased arterial stiffness is independently associated with metabolic syndrome and damage index in systemic lupus erythematosus patients

OBJECTIVES

We evaluated whether traditional or non-traditional cardiovascular (CV) risk factors and systemic lupus erythematosus (SLE)-related risk factors were associated with pathological arterial stiffness measured by pulse wave velocity (PWV) adjusted for patients' age and blood pressure.

METHOD

CV risk factors were measured in the 46 SLE female patients studied. Activity and organ damage were assessed by the SLE Disease Activity Index (SLEDAI) and the Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index, respectively. Other lupus-related parameters and information concerning treatment were recorded. Subclinical atherosclerosis was assessed by PWV calculated from pulse wave recording by Doppler, a non-invasive method to measure arterial stiffness. Multivariate logistic regression analysis was used to identify independent determinants of increased PWV.

RESULTS

PWV was categorized as normal or pathological arterial stiffness following the reference values adjusted by age and blood pressure recently published by the European Society of Cardiology. Pathological PWV was associated with CV risk factors including homocysteine (p = 0.01), high-sensitivity C-reactive protein (hs-CRP; p = 0.03), uric acid (p = 0.01), and metabolic syndrome (p = 0.007). With regard to SLE-specific risk factors, a significant association was found between PWV and SLICC/ACR score (p = 0.006). Multivariate analysis showed that increased PWV was independently associated with metabolic syndrome [odds ratio (OR) 6.6, 95% confidence interval (CI) 1.2-38, p = 0.03] and SLICC/ACR score (OR 1.5, 95% CI 1-2.32, p = 0.05).

CONCLUSIONS

We have found a close link between metabolic syndrome and SLICC/ACR score with increased aortic stiffness. These variables might be an indicator of subclinical atherosclerosis in SLE women without clinical evidence of atherosclerotic cardiovascular disease (CVD).

Serum Uric Acid

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