Serum uric acid plays a protective role for bone loss in peri- and postmenopausal women: a longitudinal study

Real world fracture prediction of fracture risk assessment tool (FRAX), osteoporosis self-assessment tool for Asians (OSTA) and one-minute osteoporosis risk test: An 11-year longitudinal study

Introduction

Fractures affect people's quality of life especially in the elders. One of the most important risk factors is osteoporosis. There are many screening tools to predict osteoporosis and fractures. We aimed to compare the predictive validity of three commonly used screening tools: fracture risk assessment tool (FRAX), osteoporosis self-assessment tool for Asians (OSTA) and one-minute osteoporosis risk test. Among them, OSTA and one-minute osteoporosis risk test were originally developed to predict osteoporosis risks and FRAX was to predict fracture risks.

Methods

This is an 11-year longitudinal study. We enrolled 708 senior people from health examinees in Taiwan in 2010. A standardized questionnaire and blood tests were provided. Annual telephone interview was conducted to assess the real fracture status. We calculated risk scores of FRAX, OSTA, and one-minute osteoporosis risk test and compared with real-world fracture records.

Results

The mean age of the participants were 74.9 (SD 6.4). There were 356 (50.3 %) men. From 2010 to 2020, a total of 105 (14.8 %) persons suffered from fractures. Compared to people without fractures, people with fractures had higher FRAX major osteoporotic fracture risk scores (14.0 % ± 7.6 % vs.11.3 % ± 5.7 %), higher hip fracture risk scores, and higher OSTA risk (5.9 % ± 1.4 % vs. 5.3 % ± 1.3 %). Cox regression analysis showed that hazard ratios for fracture of high FRAX risk was 1.53 (95 % confidence interval (CI) 1.05-2.21), and for high OSTA risk was 1.37 (95 % CI 1.04-1.82).

Conclusions

Only OSTA and FRAX scores were satisfactory in predicting 10-year fractures.

Association between serum uric acid and bone mineral density in males from NHANES 2011-2020

Currently, the relationship between serum uric acid (SUA) and bone mineral density (BMD) in men remains controversial. This study aims to investigate the relationship between SUA and lumbar spine BMD in American men using data from the National Health and Nutrition Examination Survey (NHANES). A total of 6254 male subjects aged 12-80 years (mean age 35.52 ± 14.84 years) in the NHANES from 2011 to 2020 were analyzed. SUA was measured by DxC using the timed endpoint method, and lumbar spine BMD was measured by dual-energy X-ray absorptiometry (DXA). Multivariate linear regression models were used to explore the relationship between SUA and BMD by adjusting for age, race/Hispanic origin, drinking behavior, smoking behavior, physical activity, body mass index (BMI), poverty-to-income ratio (PIR), total protein, serum calcium, cholesterol, serum phosphorus, and blood urea nitrogen. After correcting for the above confounders, it was found that SUA was positively associated with lumbar spine BMD in the range of SUA < 5 mg/dL (β = 0.006 95% CI 0.003-0.009, P < 0.001), and BMD of individuals in the highest quartile of SUA was 0.020 g/cm2 higher than those in the lowest quartile of SUA (β = 0.020 95% CI 0.008-0.032, P = 0.003). This study showed that SUA was positively correlated with lumbar spine BMD in American men within a certain range. This gives clinicians some insight into how to monitor SUA levels to predict BMD levels during adolescence when bone is urgently needed for growth and development and during old age when bone loss is rapid.

Association of serum uric acid levels with bone mineral density and the presence of osteoporosis in Chinese patients with Parkinson's disease: a cross-sectional study

INTRODUCTION

As the population ages, the incidence of osteoporosis among patients suffering from Parkinson's disease (PD) will surge continually, and the ensuing disability from falls is becoming a serious social burden. Due to its antioxidant properties, much literature has indicated the possible ability of serum uric acid (UA) to prevent ageing-related diseases caused by oxidative stress, including osteoporosis and PD. Therefore, this study was for exploring the connection of serum UA levels with bone mineral density (BMD) and the osteoporosis presence in Chinese PD patients.

MATERIALS AND METHODS

A cross-sectional design was used to statistically analyze 42 clinical parameters obtained from 135 patients with PD treated in Wuhan Tongji Hospital during 2020-2022. Multiple stepwise linear regression and multiple logistic regression analyses were constructed for identifying the association of serum UA levels with BMD as well as osteoporosis in PD patients, respectively. With receiver operative characteristic (ROC) curves, the optimal cutoff value was acquired for serum UA in the diagnosis of osteoporosis.

RESULTS

According to the regression analysis adjusted for confounders, serum UA levels in PD patients had positive correlation with BMD at each site and negative correlation with the presence of osteoporosis (P < 0.05 for all). ROC curves determined that the optimal cutoff value for UA to perform well in diagnosing osteoporosis in PD patients was 284.27 μmol/L (P < 0.001).

CONCLUSION

Relatively higher serum UA levels in the physiological range can work as a biomarker of higher BMD, and were strongly linked to lower prevalence of osteoporosis in Chinese PD patients.

The associations between uric acid with BMDs and risk of the 10-year probability of fractures in Chinese patients with T2DM stratified by age and gender

PURPOSE

Accumulating evidence suggests that serum uric acid (SUA) plays a beneficial role in bone health in the general population through antioxidant mechanisms. However, there is controversy over the association between SUA and bone in patients with type 2 diabetes mellitus (T2DM). We aimed to investigate the association of serum UA with BMDs and future fracture risks and its potential influencing factors in those patients.

METHOD

This was a cross-sectional study of 485 patients. BMDs at femoral neck (FN), Troch and the lumbar spine (LS) were measured by DXA. The 10-year probability of fracture risk was assessed using the fracture risk assessment tool (FRAX). SUA level and other biochemical indexes were measured.

RESULTS

There were lower SUA concentrations in patients with osteoporosis/osteopenia compared with those in the normal group, which only existed in non-elderly men and elderly women with T2DM. After adjustment for potential confounders, SUA was positively associated with BMD and negatively with 10-year probability of fracture risk only in non-elderly men and elderly women with T2DM. Multiple stepwise regression analysis showed that SUA was an independent determinant of BMD and 10-year probability of fracture risk, which also occurred in the above patients.

CONCLUSION

These results implied that relatively high SUA is a protective factor for bone in T2DM patients, but the osteoprotective effect of SUA was mediated by age and gender, and persisted only in non-elderly men and elderly women. Large intervention studies are needed to further confirm the outcomes and provide possible explanations.

Association between Serum Uric Acid Levels and Bone Mineral Density in Taiwanese Elderly Population

Osteoporosis is a progressive metabolic bone disorder characterised by a decline in bone mineral density (BMD). Some previous studies have reported a controversial relationship between uric acid and osteoporosis. This cross-sectional study aimed to assess the association between serum uric acid levels and BMD in older adults from Taiwan. Data from participants aged ≥ 60 years were collected from 2008 to 2018. Furthermore, the participants were classified based on uric acid level quartiles. Regression models were used to assess the association between uric acid levels and bone health, including BMD values and risk of at least osteopenia. Crude and adjusted models of potential confounders, including age, sex and body mass index (BMI), were used. Compared with the first quartile of uric acid levels, the odds ratios for osteoporosis decreased in the higher uric acid level groups after adjustment for age, sex and BMI. The boxplot analysis showed that BMD values were higher in the groups with higher uric acid levels; moreover, the results of the multivariable linear regression model showed a consistent pattern. Notably, uric acid levels were positively correlated with BMD values. Higher uric acid levels in the elderly population might decrease the risk of at least osteopenia. As opposed to the anti-hyperuricemic policy for younger adults with a relatively lower risk of osteoporosis, BMD evaluation and urate-lowering therapy, goal adjustments should be considered for older adults with lower uric acid levels.

Interplay between fat, muscle, bone mass, and oteophytes and risk for tophaceous gout

Tophaceous gout is a common arthritis caused by the deposition of urate crystals and is related to limited joint function. Although there are reports that uric acid (UA) is associated with bone mineral density (BMD), little is known about the relationship between UA, osteophytes, and muscle. This cross-sectional case-control study was performed in patients with tophaceous gout. The control group included patients without gout. All subjects underwent BMD and body composition analyses. Age, sex, alcohol consumption, smoking, and radiography of both knees were recorded. Adjusted ORs for tophaceous gout were calculated using the logistical regression models. A total of 150 male patients were enrolled, including 65 individuals with tophaceous gout and 85 without gout. The mean age of the patients with tophaceous gout was 59.94±12.40 years, while that of individuals without gout was 61.29±11.57 years (p=0.492). Patients with tophaceous gout have a higher mean body mass index, fat mass, appendicular lean mass, BMD, and osteophytes. Multiple logistic regression analysis revealed that fat mass (OR 2.01, 95% CI 1.27 to 3.18), appendicular lean mass (OR 4.27, 95% CI 1.86 to 9.83), and osteophytes (OR 5.88, 95% CI 1.72 to 20.13) were significantly associated with tophaceous gout. In the current study, higher fat mass, high muscle mass, and osteophyte formation were found to increase the risk of tophaceous gout, as the association is the most than can be inferred from a cross-sectional study. Therefore, reducing body fat and weight management may prevent tophaceous gout.

Integrated proteomics and metabolomics analysis of lumbar in a rat model of osteoporosis treated with Gushukang capsules

BACKGROUND

Gushukang (GSK) capsules are a Chinese patented medicine that is widely used in clinics for the treatment of osteoporosis (OP). Animal experiments have revealed that the bone mineral density of osteoporotic rats increase after treatment with GSK capsules. However, the specific mechanism and target of GSK in the treatment of osteoporosis are unclear. Further studies are needed.

METHODS

Metabolomics (GC/MS) and proteomics (TMT-LC-MC/MC) with bioinformatics (KEGG pathway enrichment), correlation analysis (Pearson correlation matrix), and joint pathway analysis (MetaboAnalyst) were employed to determine the underlying mechanisms of GSK. The differential expression proteins were verified by WB experiment.

RESULTS

The regulation of proteins, i.e., Cant1, Gstz1, Aldh3b1, Bid, and Slc1a3, in the common metabolic pathway of differential proteins and metabolites between GSK/OP and OP/SHAM was corrected in the GSK group. The regulation of 12 metabolites (tyramine, thymidine, deoxycytidine, cytosine, L-Aspartate, etc.) were differential in the common enrichment metabolic pathway between GSK /OP and OP/SHAM. Differential proteins and metabolites jointly regulate 11 metabolic pathways, such as purine metabolism, pyrimidine metabolism, histidine metabolism, beta-alanine metabolism, and so on.

CONCLUSION

GSK may protect bone metabolism in osteoporotic rats by affecting nucleotide metabolism, amino acid metabolism, and the immune system.

Relationship between geriatric nutritional risk index and osteoporosis in type 2 diabetes in Northern China

BACKGROUND

Osteoporosis is a very common bone disease in the elderly population and can lead to fractures and disability. Malnutrition can lead to osteoporosis. The geriatric nutritional risk index (GNRI) is a tool used to assess the risk of malnutrition and complications associated with nutritional status in older patients and is a crucial predictor of many diseases. Hence, this study investigated the association between the GNRI and the presence of osteoporosis and assessed the value of this index for predicting osteoporosis in patients with type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional study enrolled 610 elderly patients with T2DM. General and laboratory data of the patients were collected, along with their measurements of bone mineral density (BMD). The GNRI was calculated based on ideal body weight and serum albumin (ABL) levels. Correlation analysis was performed to determine the relationship between the GNRI and BMD and bone metabolism indices. The GNRI predictive value for osteoporosis development was analyzed through logistic regression analysis and by creating a receiver operating characteristic curve (ROC), calculating the area under the curve (AUC).

RESULTS

All patients were divided into the no-nutritional risk and nutritional risk groups. Compared with the no-nutritional risk group, the nutritional risk group had a longer diabetes course, older age, higher HbA1c levels, higher prevalence of osteoporosis; lower BMI, ABL,triglyceride (TG),Calcium (Ca),25-hydroxy-vitamin-D(25(OH)D),and parathyroid hormone(PTH) and lower femoral neck BMD,total hip BMD (P < 0.05). All patients were also assigned to the non-osteoporosis and osteoporosis groups. The non-osteoporosis group had higher GNRI values than the osteoporosis group (P < 0.05). Correlation analysis revealed a positive correlation between the GNRI and lumbar BMD, femoral neck BMD, and total hip BMD (P < 0.05). After the adjustment for confounding factors, Spearman's correlation analysis revealed that the GNRI was positively correlated with Ca, 25(OH)D, and PTH and negatively correlated with alkaline phosphatase (ALP) and procollagen of type-1 N-propeptide (P1NP). Regression analysis exhibited that the GNRI was significantly associated with osteoporosis. The ROC curve analysis was performed using the GNRI as the test variable and the presence of osteoporosis as the status variable. This analysis yielded an AUC for the GNRI of 0.695 and was statistically significant (P < 0.05).

CONCLUSIONS

A lower GNRI among T2DM patients in northern China is associated with a higher prevalence of osteoporosis.

Uric Acid Levels Are Associated with Bone Mineral Density in Mexican Populations: A Longitudinal Study

Background: Inconsistent epidemiological evidence between uric acid (UA) and bone mineral density (BMD) has been observed. Therefore, we evaluated the association between UA and BMD in Mexican adults. Methods: This analysis was conducted on 1423 participants from the Health Workers Cohort Study. We explored cross-sectional associations using linear regression and longitudinal associations using fixed-effects linear regression by sex and age groups (<45 and ≥45 years). Results: In females <45 years old, the cross-sectional analysis showed that UA levels were positively associated with total hip BMD. However, in the longitudinal analysis, we observed a negative association with the femoral neck and lumbar spine BMD. In contrast, in males <45 years old, we found an increase in total hip and femoral neck BMD in the groups with high levels of UA in the longitudinal association. On the other hand, in females ≥45 years old, we observed a longitudinal association between UA and loss of BMD at different sites. We did not observe an association between UA levels and BMD in males ≥45 years old. Conclusions: Our results suggest higher serum UA levels are associated with low BMD at different skeletal sites in Mexican females. Further studies are needed to delineate the underlying mechanisms behind this observation.

Differential Proteomic Identification and Bioinformatics Analysis of Femoral Neck in Elderly Female Patients with Hyperuricaemia

Background::

Serum uric acid (UA) is positively correlated with bone mineral density (BMD). However, the mechanism by which serum UA affects BMD remains unclear.

Objective::

The aim was carried out to search for the functional proteins related to serum UA and femoral neck BMD to better understand the pathophysiological mechanism of osteoporosis.

Materials and methods::

In this study, patients in the UA group (hyperuricaemia combined with femoral neck fracture) and the control group (normal uricaemia combined with femoral neck fracture) were selected according to the inclusion criteria. Total protein was extracted from the femoral neck of each patient. Fluorescence differential gel electrophoresis was used to separate the total proteins, and the differentially expressed protein spots were detected by image analysis. After enzyme digestion, peptide mass fingerprinting and database searches were performed to identify the differentially expressed proteins. DAVID software and Kyoto Encyclopedia of Genes and Genomes (KEGG) data were used for enrichment analysis of the screened differential proteins.

Results::

After mass spectrometry and database searching, 66 differentially expressed protein spots were identified between the UA group and the control group. Most differentially expressed proteins functioned in cytoskeleton formation, energy metabolism, or signal transduction. They were mainly involved in 50 biological processes, including peroxisome proliferator-activated receptor (PPAR) signalling and fatty acid metabolism. PPARγ and PLIN1 were subject to Western blotting analysis detection; results were consistent with the Label-Free result.

Conclusion::

Based on an analysis of the biological information, these proteins may be associated with the incidence and progression of the femoral neck bone tissues of hyperuricaemia patients.

Association between Serum Uric Acid Levels and Bone Mineral Density in Postmenopausal Women: A Cross-Sectional and Longitudinal Study

Background: Uric acid is one of natural antioxidants in human body. There have been several studies on the correlation between uric acid with oxidative stress and osteoporosis. However, the data are insufficient and results are controversial. In this regard, we determined the association between uric acid levels and bone mineral density (BMD) during the postmenopausal period. Methods: We analyzed data from 328 postmenopausal women (mean age, 57.3 ± 6.5 years; mean serum uric acid level, 4.6 ± 1.0 mg/dL). The participants were divided into three groups based on tertiles of the serum uric acid level. The participants receiving hormone replacement therapy (HRT), bisphosphonates, or lipid-lowering agents were included. Results: Blood urea nitrogen, serum creatinine, and serum triglyceride levels were significantly higher in the upper tertiles of uric acid levels. No significant difference was found in the mean uric acid levels between medication users and non-users. Each HRT regimen had a different mean serum uric acid level. A cross-sectional analysis showed no significant correlation between the serum uric acid levels and BMD in the spine and femoral neck (spine BMD: 1.050 ± 0.131, 1.060 ± 0.160, 1.084 ± 0.140, p = 0.22; femoral neck BMD: 0.837 ± 0.110, 0.849 ± 0.096, 0.863 ± 0.115, p = 0.28 for each tertile of uric acid). Longitudinal analysis of data from 186 women with follow-up examinations at a mean interval of 14.6 months also revealed no difference in reduction in both spine and femoral neck BMD between tertile groups of serum uric acid (the median BMD reduction for spine: −0.02, 0.01, −0.04, p = 0.95; the median BMD reduction for femoral neck: 0.008, 0.005, −0.003, p = 0.34). Conclusions: Serum uric acid level is not associated with BMD in postmenopausal women.

Betel Nut Chewing Decreased Calcaneus Ultrasound T-Score in a Large Taiwanese Population Follow-Up Study

Chewing betel nut is common in Taiwan. Although previous studies have shown that chewing betel nuts is associated with adverse health effects, findings about the impact on bone density have been inconsistent. Therefore, the aim of this study was to investigate the correlation between betel nut chewing and calcaneus ultrasound T-score in a longitudinal study of 118,856 participants from the Taiwan Biobank. Of these participants, 27,002 were followed up with for a median of 4 years. The T-score of the calcaneus was measured in the non-dominant foot using ultrasound. Multivariable analysis showed that a history of chewing betel nut (coefficient β = -0.232; p < 0.001) was significantly associated with low baseline T-score in all participants (n = 118,856). In addition, a long duration of betel nut chewing (per 1 year; coefficient β = -0.003; p = 0.022) was significantly associated with a low baseline T-score in the participants with a history of chewing betel nut (n = 7210). Further, a long duration of betel nut chewing (per 1 year; coefficient β = -0.004; p = 0.039) was significantly associated with a low ΔT-score in the participants with a history of chewing betel nut (n = 1778) after 4 years of follow-up. In conclusion, our results showed that betel nut chewing was associated with a decrease in calcaneus ultrasound T-score, and thus, it is important to stop chewing betel nut to help prevent an increased risk of osteoporosis in the Taiwanese population.

Association between higher serum uric acid levels within the normal physiological range and changes of lumbar spine bone mineral density in healthy Chinese postmenopausal women: a longitudinal follow-up study

OBJECTIVES

The aim of this study was to investigate whether higher serum uric acid (SUA) levels within the physiological range were associated with changes in lumbar spine bone mineral density (LBMD) in postmenopausal women without existing lumbar spine osteoporosis after a longitudinal follow-up of 3.09 years, and to further confirm the relationship between SUA and bone mineral density (BMD) in other sites such as femoral neck, total hip, and trochanter at follow-up.

METHODS

A longitudinal study of 175 healthy postmenopausal women without osteoporosis was conducted in Shenyang, China. BMD of the lumbar spine, femoral neck, total hip, and trochanter were measured using dual-energy x-ray absorptiometry at each visit. Pearson's correlation analysis and regression analyses were performed to determine any associations.

RESULTS

There were positive correlations between baseline SUA and BMD of the lumbar spine (P = 0.03), total hip (P = 0.04), and trochanter (P = 0.04). Moreover, higher baseline SUA levels were independently associated with LBMD decline and the odds ratio of the baseline SUA of the third quartile group was 0.12 (95% confidence interval, 0.02-0.70, P < 0.05), with P = 0.23 for the trend in baseline SUA when compared with participants in the lowest, first quartile group after adjustment for many potential confounding variables.

CONCLUSIONS

Higher SUA levels within the normal physiological range were independently associated with decreased LBMD, and SUA levels were positively related to the BMD of the lumbar spine, total hip, and trochanter in healthy Chinese postmenopausal women.

Prevalence and risk factors for bone loss in rheumatoid arthritis patients from South China: modeled by three methods

Background

To explore the prevalence of bone loss among patients with rheumatoid arthritis (RA) and healthy controls (HC) and further explored the risk factors for osteopenia and osteoporosis of RA patients.

Methods

A cross-sectional survey was undertaken in four hospitals in different districts in South China to reveal the prevalence of bone loss in patients. Case records, laboratory tests, and bone mineral density (BMD) results of patients were collected. Traditional multivariable logistic regression analysis and two machine learning methods, including least absolute shrinkage selection operator (LASSO) and random forest (RF) were for exploring the risk factors for osteopenia or osteoporosis in RA patients.

Results

Four hundred five patients with RA and 198 HC were included. RA patients had lower BMD in almost BMD measurement sites than healthy controls; the decline of lumbar spine BMD was earlier than HC. RA patients were more likely to comorbid with osteopenia and osteoporosis (p for trend < 0.001) in the lumbar spine than HC. Higher serum 25-hydroxyvitamin D3 level and using tumor necrosis factor inhibitor in the last year were protective factors; aging, lower body mass index, and increased serum uric acid might be risk factors for bone loss.

Conclusions

RA patients were more prone and earlier to have bone loss than HC. More attention should be paid to measuring BMD in RA patients aging with lower BMI or hyperuricemia. Besides, serum vitamin D and all three measurement sites are recommended to check routinely. TNFi usage in the last year might benefit bone mass.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04403-5.

Urine and Serum Electrolytes and Biochemical Values Associated with Osteoporosis in Premenopausal and Postmenopausal Women: A Longitudinal and Cross-Sectional Study Using Korean Genome and Epidemiology Study (KoGES) Cohort

Osteoporosis is a major public health concern, especially in women. This study aims to identify early biomarkers from biochemical measurements of serum and urine for recognizing the development of osteoporosis and osteopenia in premenopausal and postmenopausal women. From the Korean Genome and Epidemiology Study (KoGES) cohort, longitudinal study participants with normal bone density were enrolled and assessed for the association of baseline clinical and biochemical factors with osteoporosis development over 4 years. In addition, a cross-sectional study between normal bone density and osteopenia/osteoporosis was conducted to validate the risk factors found in the longitudinal cohort. Of the 5272 female participants in the KoGES cohort, 813 women (501 premenopausal and 312 menopausal) who had normal bone density at baseline were included in the longitudinal study. During the 4 years of follow-up, 64 patients developed osteoporosis and 354 developed osteopenia. In a multivariate logistic regression analysis, serum calcium and urine uric acid levels were significantly associated with elevated osteoporosis risk in premenopausal and postmenopausal women, respectively (risk of osteoporosis by serum calcium levels in premenopausal women: 4.03 (1.09–14.93), p = 0.037; risk of osteoporosis by urine uric acid levels in postmenopausal women: 24.08 (1.79–323.69), p = 0.016). For the cross-sectional study, serum and urine parameters were compared between women with osteopenia or osteoporosis at baseline and those with normal bone density. Urine uric acid levels were found to be significantly higher in both premenopausal and postmenopausal women with bone loss than in women with normal bone density (p < 0.001 and p = 0.004, respectively). Uric acid level in urine may be an early marker for the development of osteoporosis in women, especially after menopause.

Elevated Urate Levels Do Not Alter Bone Turnover Markers: Randomized Controlled Trial of Inosine Supplementation in Postmenopausal Women

OBJECTIVE

Observational studies have consistently demonstrated that serum urate level positively correlates with bone mineral density (BMD). We undertook this study to determine whether moderate hyperuricemia induced by inosine supplements influences bone turnover markers in postmenopausal women over a 6-month period.

METHODS

One hundred twenty postmenopausal women were recruited for a 6-month randomized, double-blind, placebo-controlled trial. Key exclusion criteria were osteoporosis, previous fragility fracture, bisphosphonate therapy, gout, kidney stones, and a urine pH level of ≤5.0. Participants were randomized in a 1:1 ratio to receive placebo or inosine. The coprimary end points were change in levels of N-propeptide of type I procollagen (PINP) and change in levels of β-C-telopeptide of type I collagen (β-CTX). Change in BMD, as measured by dual x-ray absorptiometry, was an exploratory end point.

RESULTS

Administration of inosine led to a significant increase in serum urate concentration over the study period (P < 0.0001 for all follow-up time points). At week 26, the mean change in serum urate concentration was +0.13 mmoles/liter (+2.2 mg/dl) in the inosine group and 0.00 mmoles/liter (0 mg/dl) in the placebo group. There was no difference in PINP or β-CTX levels between groups over the 6 months. There were no significant changes in bone density between groups over the 6 months. Adverse events and serious adverse events were similar between the 2 groups.

CONCLUSION

This clinical trial shows that although inosine supplementation leads to sustained increases in serum urate levels over a 6-month period, it does not alter markers of bone turnover in postmenopausal women. These findings do not support the concept that urate has direct biologic effects on bone turnover.

Correlation of oxidative stress-related biomarkers with postmenopausal osteoporosis: a systematic review and meta-analysis

Oxidative stress (OS) is implicated in postmenopausal osteoporosis (PO). Results show an imbalance between antioxidative and oxidative markers in PO. Thus, monitoring of OS-related biomarkers and keeping balance between reactive oxygen species and antioxidant system are beneficial to the diagnosis and prognosis of PO.

PURPOSE

Oxidative stress (OS) has been implicated in postmenopausal osteoporosis (PO). However, the relations between OS-related markers and PO are controversial. This study aimed to quantitatively and comprehensively assess the roles of OS-related biomarkers in PO.

METHODS

Relevant articles were retrieved from electronic databases. All OS-associated biomarkers with at least 2 independent study outcomes were meta-analyzed. The pooled standardized mean differences (SMD) with its 95% confidence intervals (CI) were presented.

RESULTS

A total of 36 studies involving 16 OS-related biomarkers were investigated. The overall results showed that total oxidant status (TOS), superoxide dismutase (SOD), hydroperoxides (HY), paraoxonase (PON1), nitric oxide (NO), and homocysteine (Hcy) were not statistically different between the PO and control groups, whereas significantly increased levels of oxidative stress index (OSI), malondialdehyde (MDA), advanced oxidation protein products (AOPP), and vitamin B12, along with decreased total antioxidant status (TAS), total antioxidant power (TAP), catalase (CAT), glutathione peroxidase (GPx), uric acid (UA), and folate, were detected in the PO group. Subgroup analysis based on biological samples displayed significantly elevated NO in erythrocyte and Hcy in serum, along with decreased SOD in serum.

CONCLUSION

Monitoring of certain OS-related biomarkers might be beneficial to the diagnosis and prognosis of PO.

Serum Uric Acid Level Is Positively Associated With Higher Bone Mineral Density at Multiple Skeletal Sites Among Healthy Qataris

BACKGROUND

Oxidative stress has been implicated as a fundamental mechanism in the decline of bone mass. Although serum uric acid (SUA) has potent antioxidant properties, the findings of many epidemiological and experimental studies couldn't draw a clear conclusion on the relation between SUA and bone health. We aim to investigate the association between SUA and bone mineral density (BMD) at different skeletal sites among healthy Qataris.

METHODOLOGY

A cross-sectional analysis including total-body and site-specific bone mineral density scores and other serological markers of 2981 healthy Qatari adults (36.4 ± 11.1 years) from the Qatar biobank database was conducted. The study participants were divided into quartiles based on the level of SUA, and the BMD was measured using dual-energy X-ray absorptiometry (DXA). Multiple regression analyses were applied to investigate the association between SUA and BMD adjusting for multiple confounding factors.

RESULTS

High levels of SUA were significantly associated with the increased bone mineral density of the total body and at site-specific skeletal locations after adjusting for age and gender (p-value < 0.001). Further adjustment for body mass index (BMI), smoking, vitamin D, alkaline phosphatase, and estimated glomerular filtration rate (eGFR) levels attenuated the association but the association remained significant for individuals with high SUA levels (p-value ≤ 0.01).The association between SUA and BMD was not significant in non-obese, females, young adults, and smokers. However, no interaction was found between SUA and age, gender, BMI and smoking.

CONCLUSION

Higher SUA levels are associated with a high bone density among healthy Qatari adults. However, such observation demands further investigations to outline the underlying mechanisms.

Association between the metabolome and bone mineral density in a Chinese population

BACKGROUND

Osteoporosis is a common metabolic bone disease, which always leads to osteoporotic fractures. Biomarkers of bone mineral density (BMD) are helpful for prevention and early diagnosis of osteoporosis. This study aims to identify metabolomic biomarkers of low BMD.

METHODS

We included 701 participants who had BMD measures by dual-energy X-ray absorptiometry scans and donated fasting plasma samples from three clinical centres as a discovery set and another 278 participants from the fourth centre as an independent replication set. We used a liquid chromatography-mass spectrometry-based metabolomics approach to profile the global metabolites of fasting plasma.

FINDINGS

Among the 265 named metabolites identified in our study, six were associated with low BMD (FDR-adjusted P<0.05) in the discovery set and were successfully validated in the independent replication set. The circulating levels of five metabolites, i.e., inosine, hypoxanthine, PC (O-18:0/22:6), SM (d18:1/21:0) and isoleucyl-proline were associated with decreased odds of low BMD, and PC (16:0/18:3) level was associated with increased odds of low BMD. Per 1-SD increase in a composite metabolite score of these six metabolites was associated with about half decreased odds of low BMD (odds ratio 0.59, 95% confidence interval: 0.52-0.68). Furthermore, introduction of a panel of metabolites selected by elastic net regression to a prediction model of classical risk factors and plasma biomarker of bone resorption substantially improved the prediction performance for low BMD (AUCs: 0.782 vs. 0.698, P=0.002).

INTERPRETATION

Metabolomics profiling may help identify novel biomarkers of low BMD and be helpful for early diagnosis of osteoporosis beyond the current clinical index.

FUNDING

This study was supported by the National Key R&D Program of China [2018YFC2001500 to J.S.], Shanghai Municipal Science and Technology Major Project [2017SHZDZX01], the National Natural Science Foundation of China [Key Program, 91749204 to J.S.], the National Natural Science Foundation of China [General Program, 81771491 to J.S.], the Project of Shanghai Subject Chief Scientist [2017BR011 to J.S.], Grants from the TCM Supported Project [18431902300 to J.S.] from the Science and Technology Commission of Shanghai Municipality, and the National Natural Science Foundation of China [General Program, 81972089 to Z.X.]. Y.Z. was supported by the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the National Natural Science Foundation of China [81973032].

Pathophysiology of hyperuricemia and its clinical significance - a narrative review

Hyperuricemia, i.e. increased serum uric acid (UA) concentration, is a common problem in clinical practice. While there are clear guidelines concerning management of symptomatic hyperuricemia in acute conditions such as gout, urolithiasis or acute urate nephropathy, less is known about their secondary prevention. Moreover, despite the ongoing debate on the role of UA in the pathogenesis of chronic kidney disease, hypertension, cardiovascular disease and heart failure, the management of asymptomatic hyperuricemia in patients with these chronic conditions is still mainly up to physicians' judgement. Individual considerations should always be taken into account when prescribing urate-lowering therapy. In this narrative review study, we attempt to present current trends concerning treatment of patients with either symptomatic or asymptomatic hyperuricemia in the light of the available knowledge on the role of hyperuricemia in the development of gout, renal, cardiovascular and other diseases.

Relationships between serum uric acid concentrations, uric acid lowering medications, and vertebral fracture in community-dwelling elderly Japanese men: Fujiwara-kyo Osteoporosis Risk in Men (FORMEN) Cohort Study

PURPOSE

The association between serum concentrations of uric acid (UA), a potent endogenous antioxidant, and fracture risk has not yet been examined for morphometric vertebral fracture (VF). This study aimed to determine whether serum UA concentrations are associated with risks of clinical osteoporotic fracture (OPF) and morphometric VF after adjusting for confounding factors including UA-lowering medications (ULMs).

MATERIALS AND METHODS

A total of 2012 Japanese men aged ≥65 years completed the baseline study, which included serum UA measurement and X-ray absorptiometry-based VF assessment. We conducted a follow-up study five years later to identify incident OPFs and VFs. OPF was identified through interviews. Incident VF was defined as a vertebra which showed reduction in any of its anterior, central, or posterior heights by ≥20% during follow-up, and satisfied grade one or higher fracture criteria in Genant's method on follow-up images. Bone mineral density (BMD) of the hip and spine was measured by dual-energy X-ray absorptiometry at baseline and follow-up.

RESULTS

We identified 45 clinical OPFs from 2000 men and 39 VFs from 1530 men during a mean follow-up period of 4.3 years. Hip BMD was significantly higher in higher UA concentration groups after adjusting for age and body mass index. A significantly decreased multivariate-adjusted odds ratio (OR) of incident VF was observed for the highest quartile groups of serum UA concentrations compared with the lowest quartile group (OR: 0.17, 95% confidence interval: 0.05-0.62). This OR remained significant after further adjusting for ULM use. ULM users in the lowest quartile group of serum UA concentrations had a significantly higher incidence rate of VF compared to the other quartile groups.

CONCLUSIONS

Higher serum UA concentrations were associated with a lower risk of morphometric VF independently of ULM in Japanese elderly men. Excessive reduction of serum UA concentrations by ULM might increase VF risk.

Higher serum uric acid levels are associated with reduced risk of hip osteoporosis in postmenopausal women with rheumatoid arthritis

Although the positive correlation between serum uric acid (UA) levels and bone mineral density (BMD) has been reported in the general population, there are little data regarding the effect of serum UA levels on bone loss in patients with rheumatoid arthritis (RA).We investigated whether increased serum UA levels were associated with a reduced risk of osteoporosis in postmenopausal women with RA.In this retrospective cross-sectional study, 447 postmenopausal female patients with RA and 200 age-matched, postmenopausal healthy controls underwent BMD examination by dual energy x-ray absorptiometry and serum UA levels measurement. Osteoporosis was diagnosed when the T-score was <-2.5.The median UA level in postmenopausal RA patients was found to be significantly lower than that in the healthy women (4 vs 4.1 mg/dL, P = .012) and the frequency of osteoporosis incidence in the lumbar spine, hip, and either site in RA patients was 25.5%, 15.9%, and 32.5%, respectively; the values were significantly higher than those of the controls. After adjusting for confounding factors, a significantly lower risk for osteoporosis of the hip in RA patients was observed within the highest quartile (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.16-0.72, P = .021) and the second highest quartile (OR = 0.44, 95% CI = 0.2-0.95, P = .038) of serum UA levels as compared with the lowest quartile, but this association was not found to be consistent with respect to the lumbar spine. Serum UA levels also showed an independently positive correlation with femoral neck BMD (β = 0.0104, P = .01) and total hip BMD (β = 0.0102, P = .017), but not with lumbar BMD.Our data suggest that UA may exert a protective effect on bone loss in RA, especially in the hip.

Association of Serum Uric Acid Status With Bone Mineral Density in Adolescents Aged 12-19 Years

Aims: Evidence linking serum uric acid (sUA) and bone mineral density (BMD) in adolescents is very limited. To the best of our knowledge, only one report has focused on the relationship between sUA and BMD in adolescents. Thus, this study aimed to determine the association between sUA and total BMD in adolescents aged 12-19 years. Methods: A cross-sectional study was conducted on a sample composed of non-institutionalized US population from the National Health and Nutrition Examination Survey. Weighted multivariate linear regression models were used to evaluate the association between sUA and total BMD. Subgroup analyses were further performed. Results: sUA positively correlated with total BMD in the multiple regression model after adjusting for potential confounders. However, in the subgroup analyses stratified by sex, age, or race/ethnicity, the association between sUA and total BMD followed an inverted U-shaped curve in female adolescents, adolescents aged 16-19 years, and other race/ethnicity. Conclusions: Our results suggested that the correlation between sUA level and total BMD differed by sex. The increased sUA level would be beneficial to bone health in adolescents with low sUA levels, but for female adolescents, a higher sUA level (turning point, 3.9 mg/dL) may have an adverse effect on bone health.

Changes in Adipose Tissue Distribution and Association between Uric Acid and Bone Health during Menopause Transition

Despite convincing experimental evidence, epidemiological studies on the effects of serum uric acid (SUA) on bone health are still conflicting since factors influencing SUA bioavailability have not been adequately considered. To shed some light on this issue, we investigated the impact of adiposity and menopause status on the relationship between SUA and bone health. We examined SUA in relation to bone mineral density (BMD) at different skeletal sites and with markers of bone metabolism in 124 pre-menopausal and 234 post-menopausal women and assessed whether adiposity, evaluated by anthropometry and dual x-ray absorptiometry (DXA), might have a discriminant role. After conservative adjustment (covariates: age, hormones treatment, smoking and time since menopause), SUA showed a significant and positive association with total hip BMD (β = 0.220, p < 0.01) among postmenopausal women, maintained also after adjustment for legs adiposity. Notably, stratification for waist circumference quartiles revealed that the correlation between SUA and total hip BMD was significant (r = 0.444, p = 0.001) in the highest quartile (91–100 cm). Our results suggest that SUA might be beneficial for bone health in postmenopausal women being characterized by a more android fat distribution, ascribing to SUA a discriminant role during menopause transition, potentially relevant also for men.

Osteoporosis in Rheumatic Diseases

Osteoporosis is a chronic disease characterized by an increased risk of fragility fracture. Patients affected by rheumatic diseases are at greater risk of developing osteoporosis. The purpose of the present review is to discuss the pathogenesis, epidemiology, and treatment of osteoporosis in patients affected by rheumatic diseases with special focus for rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, systemic lupus erythematosus, systemic sclerosis, vasculitides, Sjogren syndrome, and crystal-induced arthritis.

The Paradoxical Role of Uric Acid in Osteoporosis

Because of its high prevalence worldwide, osteoporosis is considered a serious public health concern. Many known risk factors for developing osteoporosis have been identified and are crucial if planning health care needs. Recently, an association between uric acid (UA) and bone fractures had been explored. Extracellular UA exhibits antioxidant properties by effectively scavenging free radicals in human plasma, but this benefit might be disturbed by the hydrophobic lipid layer of the cell membrane. In contrast, intracellular free oxygen radicals are produced during UA degradation, and superoxide is further enhanced by interacting with NADPH oxidase. This intracellular oxidative stress, together with inflammatory cytokines induced by UA, stimulates osteoclast bone resorption and inhibits osteoblast bone formation. UA also inhibits vitamin D production and thereby results in hyper-parathyroidism, which causes less UA excretion in the intestines and renal proximal tubules by inhibiting the urate transporter ATP-binding cassette subfamily G member 2 (ABCG2). At normal or high levels, UA is associated with a reduction in bone mineral density and protects against bone fracture. However, in hyperuricemia or gout arthritis, UA increases bone fracture risk because oxidative stress and inflammatory cytokines can increase bone resorption and decrease bone formation. Vitamin D deficiency, and consequent secondary hyperparathyroidism, can further increase bone resorption and aggravated bone loss in UA-induced osteoporosis.

Gout is not associated with the risk of fracture: a meta-analysis

BACKGROUND

Numerous quantitatively based studies measuring the association between gout and the risk of fractures remain inconclusive. In order to determine whether gout could increase the risk of fractures, a meta-analysis was performed systematically.

METHODS

Electronic databases, MEDLINE/PubMed, Embase, and Cochrane Library were systematically searched to identify studies evaluating the association of gout and the risk of fractures. No restrictions on language, publication date, or journal of publication were imposed. Meta-analysis was performed to pool the outcome estimates of interest such as fracture incidence, fracture risk, and fracture risk in different sites and at different time points in the follow-up period.

RESULTS

Screening determined that seven studies involving a total of 684,964 participants (151,002 in the gout group and 533,962 in the control group) were deemed viable for inclusion in the meta-analysis. The results of the analysis showed that gout would not significantly have a relatively higher risk of any fracture (RR = 1.11, 95% CI 0.98-1.26). Subgroup analysis showed consistent results for sexuality (female: RR = 1.13, 95% CI 0.93-1.37; male: RR = 0.99, 95% CI 0.91-1.07) and several occurring sites (humerus, wrist, vertebra, hip, upper limbs, and lower limbs). Additionally, the results demonstrated that urate-lowering drugs prescribed early during disease had neither adverse nor beneficial effect on the long-term risk of fractures (RR = 0.89, 95% CI 0.76-1.05).

CONCLUSIONS

This meta-analysis confirmed that gout was not associated with an increased risk of fractures. Urate-lowering drugs prescribed early during the course of disease had neither adverse nor beneficial effect on the long-term risk of fractures.

Examining the causal role of leptin in bone mineral density: A Mendelian randomization study

Leptin, a small polypeptide hormone secreted by the adipocytes, controls body weight and gonadal function by binding to a special receptor located in the hypothalamus. Observational studies have demonstrated a controversial association between leptin and bone mineral density (BMD), and functional studies of the relationship between leptin and BMD still largely vary by different studies. Using SNPs strongly associated with leptin levels in 52,140 individuals, we conducted a two-sample Mendelian randomization study to identify whether genetically lowered leptin levels were associated with BMD by using an inverse-variance weighted method, a weighted median method, MR-Egger and Robust Adjusted Profile Score. We found that circulating leptin levels may causally decrease lumbar spine BMD (effect size = -0.45, 95% CI: -0.82, -0.083; p value = 0.016). The association estimates of circulating leptin levels on femoral neck, forearm and total body BMD were not significant. Our study suggests that genetically predicted higher circulating leptin was associated with lower LS-BMD.

Specific higher levels of serum uric acid might have a protective effect on bone mineral density within a Chinese population over 60 years old: a cross-sectional study from northeast China

Background and objective: Oxidative stress has been demonstrated to be a mechanism that leads to bone mass reduction, and according to many studies, serum uric acid (UA) is a strong endogenous antioxidant that can protect bone mineral density (BMD). To date, there have been no large-scale, cross-sectional studies based on the population in northeast China to assess the relationship between serum UA and BMD. Therefore, we examined the association between serum UA and BMD among a Chinese population older than 60 years old in northeast China.

Methods: This research was a cross-sectional study of 3465 Chinese individuals over 60 years old in nine communities from the city of Shenyang, which is the capital of northeast China’s Liaoning Province. Participants were stratified into three groups by serum UA or BMD levels, and then Pearson’s correlation analysis and multiple regression analysis were used to study the relationship between serum UA and BMD.

Results: We found that participants with higher serum UA levels had significantly greater BMD and T-values compared to those of participants with lower serum UA levels. After adjusting for confounding factors, Pearson’s correlation analysis and multiple regression analysis showed that higher serum UA levels remained associated with higher BMD levels (P<0.05). In different models, the prevalence of osteoporosis (OP) among participants with higher serum UA levels was reduced by 23% to 26% (P<0.05) compared to that in individuals with lower serum UA levels. In addition, serum UA levels were negatively correlated with estimated glomerular filtration rate (eGFR) and positively correlated with 25-hydroxy vitamin D₃ [25-(OH)D₃] (P<0.05).

Conclusion: We concluded that higher serum UA levels are associated with greater BMD, and serum UA might have a protective effect on bone metabolism due to its antioxidant properties.

Allantoin reduces cell death induced by cisplatin: possible implications for tumor lysis syndrome management

Massive lysis of tumor mass in cancer patients under chemotherapy regimens generates high levels of uric acid, leading to what is known as tumor lysis syndrome (TLS). Rasburicase, a recombinant urate oxidase, converts urate to allantoin, which is readily excreted by the kidneys. Even though there is a high production of allantoin from urate in cancer patients following rasburicase treatment, there are no studies on how allantoin excess could interfere with chemotherapy. We have evaluated allantoin interference with cisplatin efficiency on the lung cancer cell line H460 in vitro. The cells were treated with cisplatin (33 µM), with or without allantoin, for 48 h, in the presence or absence of UV light, and N-acetyl-L-cysteine (NAC) for 24 h. Cell viability, cell cycle, ROS production, apoptosis and immunoblot assays were performed. We showed that allantoin reduced the apoptosis induced by cisplatin in the H460 cell line. However, the activity of carboplatin and oxaliplatin, betulinic acid, TIBA, UV and H₂O₂ was not affected by allantoin. NMR spectroscopy showed that allantoin reduces cisplatin activity through direct interaction with cisplatin.

Review of the Literature Examining the Association of Serum Uric Acid with Osteoporosis and Mechanistic Insights into Its Effect on Bone Metabolism

Background And Objective:

Osteoporosis is a common bone disorder that increases susceptibility to fragility bone fractures. The clinical and public health repercussions of osteoporosis are huge due to the morbidity, mortality, and cost of medical care linked with fragility fractures. Clinical assessment of osteoporotic risk factors can help to identify candidates at an early stage that will benefit from medical intervention and potentially lowering the morbidity and mortality seen with fractures and complications. Given this, research is ongoing to evaluate the association of osteoporosis with some novel or less well-studied risk factors/bio-markers such as uric acid (UA).

Discussion:

Uric acid’s antioxidant activity has been proposed to be one of the factors responsible for increasing longevity and lowering rates of age-related cancers during primate evolution, the level of which increased markedly due to loss of uricase enzyme activity (mutational silencing). Accumulated evidence shows that oxidative stress is the fundamental mechanism of age-related bone loss and acts via enhancing osteoclastic activity and increasing bone resorption. Antioxidant substances such as ascorbic acid scavenge free radicals are positively related to bone health. Thus, it is hypothesized that uric acid holds bone-protective potential owing to its potent antioxidative property. Several correlation studies have been conducted globally to investigate the relationship between serum uric acid with bone mineral density and osteoporosis. Few pre-clinical studies have tried to investigate the interaction between uric acid and bone mineral density and reported important role played via Runt-related transcription factor 2 (RUNX2)/core-binding factor subunit alpha-1 (CBF-alpha-1), Wingless-related integration site (Wnt)-3a/β-catenin signaling pathway and 11β Hydroxysteroid Dehydrogenase type 1.

Conclusion:

In this review, the authors provided a comprehensive summary of the literature related to association studies reported in humans as well work done until date to understand the potential cellular and molecular mechanisms that interplay between uric acid and bone metabolism.

Higher serum uric acid is associated with higher lumbar spine bone mineral density in male health-screening examinees: a cross-sectional study

Bone health has been associated with oxidative stress and antioxidants have received interest to this end. Serum uric acid (SUA), an end product of purine metabolism in humans, has recently shown antioxidant properties regarding bone health, but there are conflicting results. The aim of this study was to investigate the relationship between SUA levels and lumbar spine bone mineral density (BMD) in clinically apparently healthy males aged 40-60 years. We performed a cross-sectional study of 6588 Korean males who completed a health-screening program from January 2011 to December 2014. Of the study participants, the mean age was 48.2 ± 10.7 years. Multiple regression analyses resulted in a significant positive association with lumbar spine BMD across SUA quintiles in a dose-response manner after adjusting for various confounding factors (p = 0.013); for each 1 mg/dl increase of SUA, BMD rose by 0.0054 g/cm² (p = 0.004). Stratified analyses revealed that this association between SUA and lumbar spine BMD was consistently observed across all clinically relevant subgroups. The present study demonstrated a positive association in males between SUA and lumbar spine BMD, suggesting that SUA could have a profitable effect on bone metabolism.

Oxidative stress as a possible pathogenic cofactor of post-menopausal osteoporosis: Existing evidence in support of the axis oestrogen deficiency-redox imbalance-bone loss

Post-menopausal osteoporosis (PO) is one of the major health issues associated with menopause-related oestrogen withdrawal. Despite the intense research and the relevant progress achieved in the last two decades, the pathogenic mechanism underlying PO is still poorly understood. As a consequence of this gap in the knowledge, such disorder and the related complications are still difficult to be effectively prevented. A wealth of experimental and epidemiological/clinical evidence suggests that the endocrine change associated to menopausal transition might lead to a derangement of redox homeostasis, that is, the prelude to the health-threaten condition of oxidative stress (OxS). In turn, this (bio)chemical stress has been widely hypothesized to contribute, most likely in synergy with inflammation, to the development of menopause-related diseases, including PO. The main aim of this review is to discuss the current literature evidence on the association between post-menopausal oestrogen withdrawal, OxS and PO. It is also aimed to provide a critical overview of the most significant epidemiological studies on the effects of dietary antioxidants on bone health and to devise a strategy to overcome the limitations emerged and controversial results.

Positive association between serum uric acid and bone mineral density in Chinese type 2 diabetes mellitus stratified by gender and BMI

Accumulating evidence has demonstrated that serum uric acid (UA), a natural powerful antioxidant, plays a beneficial role in bone health in the general population. However, few reports are available on the association between serum UA and bone in patients with type 2 diabetes mellitus (T2DM). We therefore investigated whether the benefit of serum UA for bone health was still present in those patients. 626 males and 609 postmenopausal females with T2DM were enrolled in this cross-sectional study. Serum UA concentrations and bone mineral density (BMD) measured at lumbar spine, femoral neck and total hip by dual-energy X-ray absorptiometry were obtained from all subjects. Meanwhile, data on osteoporosis prevalence, glucose metabolism, bone turnover markers and other serum biochemical indexes were collected. After adjustment for potential confounders, the results suggested that serum UA was positively associated with BMD in patients with normal weight, but this positive association varied by gender and skeletal sites in overweight T2DM patients [body mass index (BMI) ≥ 25 kg/m²]. Moreover, significantly lower odds ratios (ORs) for osteoporosis were found in postmenopausal patients with the highest UA tertile and male patients with medium UA tertile [adjusted OR 0.315, 95% confidence interval (CI) 0.170-0.581 for postmenopausal patients; adjusted OR 0.464, 95% CI 0.225-0.955 for male patients]. The positive association between serum UA and BMD found in Chinese T2DM patients may imply that relatively high UA is a protective factor for bone in these patients. Large intervention studies are needed to further confirm the outcomes and provide possible explanations.

Effects of vitamin B12, folate, uric acid, and serum biomarkers of inflammation on bone mineral density in postmenopausal women

Introduction

Despite the accumulating evidence suggesting a possible relationship between femur and lumbar bone mineral density (BMD) and serum uric acid (UA), it is unclear whether alterations in UA levels reflect any underlying subclinical inflammatory conditions in postmenopausal osteoporosis. In addition, the mechanistic link between osteoporosis and dietary factors including vitamin B₁₂ and folate in postmenopausal women is still obscure. The aim of the present study is to investigate the association between serum vitamin B₁₂, folate, UA, and subclinical inflammatory markers and BMD measurements in postmenopausal women.

Material and methods

One hundred and eighty-four postmenopausal women were recruited for the present study. Clinical data, as well as serum vitamin B₁₂, folate, UA, conventional inflammatory markers, and other related biochemical markers, were assessed for each subject. Bone mineral density measurements of proximal femur and lumbar spine were taken using dual-energy X-ray absorptiometry. Correlation analysis was performed between serum vitamin B₁₂, folate, UA and other biochemical and metabolic parameters.

Results

Although no association was found between serum inflammatory markers, vitamin B₁₂ and folate levels with femur neck and lumbar spine BMD measurements, elevated UA levels were observed in subjects with normal BMD values. Higher BMD values were obtained in higher UA tertiles. UA (p < 0.001) and BMI (p = 0.003) were found to be correlated with femur neck BMD measurements.

Conclusions

The femoral and lumbar BMD measurements were associated with serum UA levels. Higher serum UA levels were found to have a protective effect on postmenopausal osteoporosis irrespective of inflammation and dietary factors.

Association of serum uric acid levels with osteoporosis and bone turnover markers in a Chinese population

Recent evidence shows that uric acid is protective against some neurological diseases, but can be detrimental in many metabolic and cardiovascular disorders. In this study, we examined the association between serum uric acid levels and bone metabolism in Chinese males and postmenopausal females. A total of 943 males and 4256 postmenopausal females were recruited in Shanghai. The levels of serum uric acid and bone turnover markers (BTMs) were detected along with other biochemical traits. In addition, the fat distribution was calculated through MRI and image analysis software, and bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry. For postmenopausal females, the prevalence of osteoporosis was significantly lower in the hyperuricemia group compared with the normouricemic group (P=4.65E-06). In females, serum uric acid level was significantly associated with osteoporosis, with odds ratio (OR) and 95% confidence interval (95% CI) of 0.844 [0.763; 0.933] (P=0.0009) after adjusting for age, body mass index, HbA1c, lean mass, visceral and subcutaneous fat areas, albumin, 25-hydroxyvitamin D3 [25(OH)D3], and parathyroid hormone (PTH). In females, serum uric acid level was positively correlated with the BMD of the femoral neck (β±SE: 0.0463±0.0161; P=0.0042), total hip (β±SE: 0.0433±0.0149; P=0.0038) and L1-4 (β±SE: 0.0628±0.0165; P=0.0001) after further adjusting for age, BMI, HbA1c, lean mass, VFA, SFA, albumin, 25(OH)D3 and PTH. Regarding BTMs, serum uric acid level was negatively correlated with N-terminal procollagen of type I collagen (PINP) in females (β±SE: -0.1311±0.0508; P=0.0100). In summary, our results suggest that uric acid has a protective effect on bone metabolism independent of body composition in Chinese postmenopausal females.

Association between metabolic syndrome and bone mineral density in a Taiwanese elderly population

Previous studies have demonstrated uncertainty regarding the effect of metabolic syndrome (MetS) on bone. In the present work, we investigated the association between MetS, its components, and decreased bone mineral density (BMD) in a cross-sectional study of patients who underwent BMD measurement by dual-energy X-ray absorptiometry during a health examination. Decreased BMD was defined as either osteopenia or osteoporosis. MetS components and body mass index (BMI) were compared between individuals with normal and decreased BMD, and simple and multivariate logistic regression analyses were used to evaluate the association between the variables and decreased BMD in women and men. Among 1162 subjects in the study, the mean age was 59.9 ± 7.3 years, and 59.5% were men. The prevalence of MetS and osteoporosis was 34.2 and 19.6%, respectively. MetS was positively associated with BMD in men, while in women it was negatively associated with BMD. Regarding the relationship between MetS components and BMD, we found that in women, waist circumference (WC) and systolic and diastolic blood pressure were negatively associated with BMD, while high-density lipoprotein cholesterol (HDL-C) was positively associated. In men, WC and fasting glucose were positively associated with BMD, while HDL-C was negatively associated. We also found that an increase in the number of MetS components resulted in a significantly increased positive association with BMD, both before and after adjusting for age, in men but not in women, revealing a gender difference in the correlation between MetS components and BMD.

Raised serum uric acid is associated with higher bone mineral density in a cross-sectional study of a healthy Indian population

Purpose

Oxidative stress has been implicated as a fundamental mechanism in the decline of bone mass. Reactive oxygen species are reported to suppress osteoblast generation and differentiation and enhance osteoclast development and activity. Increasing evidence suggests favorable effect of serum uric acid (UA) on bone metabolism due to its antioxidant properties. Therefore, we investigated the association between serum UA levels and bone mineral density (BMD) in healthy adult Indian subjects.

Materials and methods

We reviewed the medical records of 524 subjects who had undergone preventive health check-ups in a tertiary care hospital that included UA and BMD measurements at femur neck, total femur, and lumbar spine. Subjects concomitantly taking drugs or having a medical condition that would affect the bone metabolism or UA levels were excluded.

Results

The final analysis included 310 subjects (mean age: 47.2±12.2 years; females: 43.5%; males: 56.5%). Study population was categorized into two groups based on the group median value for UA (ie, 5.4 mg/dL). BMD was significantly higher at all skeletal sites in subjects with UA >5.4 mg/dL compared to subjects with UA ≤5.4 mg/dL (p<0.001). On correlation analysis, UA was positively associated with BMD at all skeletal sites (r=0.211–0.277; p<0.05). The correlation remained significant after controlling for age (p<0.05) and lifestyle factors (smoking, alcohol use, physical activity, and diet; p<0.05) independently. UA significantly (p<0.001) accounted for 4.5%–7.7% of the variance in BMD (r²=0.045–0.077) in unadjusted model and 1.6%–3.2% of the variance (p<0.05) when adjusted for age and body mass index combined at lumbar spine and right femur neck, respectively.

Conclusion

We conclude that raised UA levels are associated with higher BMD at all skeletal sites and UA may have a protective role in bone metabolism owing to its antioxidant effect.

Lack of Evidence that Soluble Urate Directly Influences Bone Remodelling: A Laboratory and Clinical Study

INTRODUCTION

Numerous observational studies have reported that serum urate concentration positively correlates with bone density and reduced risk of fractures. The aim of this study was to examine whether soluble urate directly influences bone remodelling.

METHODS

In laboratory studies, the in vitro effects of soluble urate were examined in osteoclast, osteoblast and osteocyte assays at a range of urate concentrations consistent with those typically observed in humans (up to 0.70 mmol/L). The clinical relevance of the in vitro assay findings was assessed using serial procollagen-1 N-terminal propeptide (P1NP) and Month 12 bone density data from a randomised controlled trial of allopurinol dose escalation in people with gout.

RESULTS

Addition of urate in the RAW264.7 cell osteoclastogenesis assay led to small increases in osteoclast formation (ANOVA p = 0.018), but no significant difference in bone resorption. No significant effects on osteoclast number or activity were observed in primary cell osteoclastogenesis or resorption assays. Addition of urate did not alter viability or function in MC3T3-E1 pre-osteoblast, primary human osteoblast, or MLO-Y4 osteocyte assays. In the clinical trial analysis, reducing serum urate over a 12 month period by allopurinol dose escalation did not lead to significant changes in P1NP or differences in bone mineral density.

CONCLUSION

Addition of soluble urate at physiological concentrations does not influence bone remodelling in vitro. These data, together with clinical trial data showing no effect of urate-lowering on P1NP or bone density, do not support a direct role for urate in influencing bone remodelling.

Association between lumbar bone mineral density and serum uric acid in postmenopausal women: a cross-sectional study of healthy Chinese population

Partial correlation and regression analyses were used in this study. We showed that there is a linear relationship between bone mineral density and serum uric acid within the normal physiologic range, and higher serum uric acid levels had a protective effect on bone loss in postmenopausal osteoporosis.

PURPOSE

The significance of the relationship between lumbar bone mineral density ⁽BMD) and serum uric acid (SUA) levels is unclear. The aims of this study were to investigate on a population-level the association between lumbar BMD and SUA within the normal physiologic range and to determine whether SUA plays a protective role in bone loss in healthy postmenopausal Chinese women.

METHODS

This was a community-based cross-sectional study involving 390 healthy postmenopausal women, 47-89 years of age, conducted in Shenyang, China. The BMD was measured at the lumbar spine using dual-energy X-ray absorptiometry (DXA). The SUA levels were obtained at each DXA visit. Partial correlation and regression analyses were applied to determine the associations.

RESULTS

The SUA levels were significantly different between the normal BMD, osteopenia, and osteoporosis groups. The lumbar BMD was positively correlated with SUA in postmenopausal women after adjustment for age (r = 0.212). After adjustment for age, body mass index, systolic blood pressure, diastolic blood pressure, hip circumference, cigarette smoking, alcohol consumption, milk intake, physical exercise, fracture history, total protein, total bilirubin, triglycerides, total cholesterol, high-density lipoprotein cholesterol, fasting blood glucose, serum calcium, and estimated glomerular filtration rate, the lumbar BMD was associated with SUA and the odds ratio of the third SUA quartile was 0.408 (95%CI, 0.198-0.841, P = 0.015), compared to the first quartile of SUA levels.

CONCLUSION

The lumbar BMD was linearly associated with SUA levels within the normal physiologic range of postmenopausal women. Higher SUA levels had a protective effect on bone loss in postmenopausal osteoporosis.

The association between serum uric acid level and the risk of fractures: a systematic review and meta-analysis

Controversy has arisen in regarding the association between serum uric acid (UA) and fracture risk. Therefore, we conducted a systemic review and meta-analysis by pooling estimate of five prospective studies (29,110 participants). Results showed that an increased serum UA level is associated with a lower risk of fracture. Numerous studies have demonstrated that high serum UA is a relevant risk factor for a wide variety of diseases, whereas new understanding in serum uric acid follows recent reports demonstrating a protective role of UA in health status. However, the association between serum UA and fracture remains controversial. Therefore, we conduct a systemic review and meta-analysis to determine whether elevated UA level is a protective factor for fracture among prospective studies. We searched for studies published before May 6, 2016, using PubMed, Embase, and Cochrane databases, without any language restriction. The inclusion criteria were published studies investigating the association between UA and fractures. Two authors independently screened the retrieved articles in accordance to the predefined inclusion criteria. We pooled the study-specific relative risk estimates using a random-effect model for comparison of persons whose UA levels were in the top tertile with those in the bottom tertile. Factors that may predict these associations were evaluated in subgroup analysis and meta-regression. The five included prospective studies included 29,110 participants. In random-effect models that included all five included studies, the summary hazard ratios (HRs) (top vs bottom tertiles) were 079 (95% CI, 0.69 to 0.89), without evidence of heterogeneity (P for heterogeneity = 0.458; I ² = 0%). Similar results were shown when pooling estimate of three higher-quality studies (HR 0.80 95% CI, 0.69 to 0.93). The association between UA and fracture remained in sensitivity and subgroup analyses. An increased serum UA level is shown to be associated with a lower risk of fracture, albeit additional large, high-quality prospective studies or a meta-analysis of individual data are still needed to verify the association.

Gout and Risk of Fracture in Women: A Prospective Cohort Study

OBJECTIVE

Uric acid may be linked to bone health through its antioxidant or prooxidant effects, thereby affecting bone resorption and formation, or through its dual inhibition of vitamin D activation and parathyroid hormone production. Results of prior studies on the relationship between uric acid and bone mineral density have been conflicting. This prospective study was undertaken to examine the relationship between gout, a disease characterized by hyperuricemia and inflammation, and risk of hip or wrist fracture in women.

METHODS

We conducted a prospective observational study of gout and risk of incident wrist and hip fracture in women participating in the Nurses' Health Study (n = 103,799 at baseline, with 14 years of follow-up for the wrist fracture analysis and 22 years of follow-up for the hip fracture analysis). Gout history and incident cases of wrist and hip fracture were assessed by biennial questionnaire. Cox proportional hazards models were used to simultaneously adjust for potential confounders.

RESULTS

In this cohort, there were 3,769 incident wrist fractures (1990-2004) and 2,147 incident hip fractures (1990-2012), with 107 wrist fractures and 117 hip fractures occurring in participants with gout. In those women with a history of gout compared with women without gout, the multivariable-adjusted relative risk of wrist fracture was 1.12 (95% confidence interval [95% CI] 0.92-1.36) and the multivariable-adjusted relative risk of hip fracture was 1.38 (95% CI 1.14-1.68).

CONCLUSION

In women, a history of gout is associated with a modestly increased risk of hip fracture, but not significantly associated with a risk of wrist fracture.

Uric acid and bone mineral density in postmenopausal osteoporotic women: the link lies within the fat

The association between serum uric acid (SUA) levels and bone mineral density (BMD) is controversial. Fat accumulation is linked to SUA and BMD, thus possibly explaining the mixed results. We found that adiposity drives part of the association between SUA and BMD in women with postmenopausal osteoporosis.

INTRODUCTION

Both positive and negative associations between SUA and BMD have been reported. SUA levels and BMD increase with higher body weight and other indices of adiposity; hence, the association between SUA and BMD might be a consequence of the confounding effect of adiposity. We investigated in this cross-sectional study whether the association between SUA and BMD is independent of measures of fat accumulation and other potential confounders.

METHODS

SUA levels, femur BMD, markers of bone metabolism, body mass index (BMI), fat mass (FM), waist circumference (WC), and abdominal visceral fat area were measured in 180 treatment-naive postmenopausal osteoporotic women (mean age 66.3 ± 8.5 years, age range 48-81 years).

RESULTS

Women with higher SUA levels (third tertile) had significantly higher femur BMD and lower cross-linked C-terminal telopeptide of type I collagen (CTX) and bone alkaline phosphatase (bALP) levels. SUA levels were positively associated with all indices of adiposity. In multivariable analysis with femur BMD as dependent variable, the association between logarithmic (LG)-transformed SUA levels and BMD (beta = 0.42, p < 0.001) was lessened progressively by the different indices of adiposity, like LG-BMI (beta = 0.22, p = 0.007), LG-WC (beta = 0.21, p = 0.01), LG-FM (beta = 0.18, p = 0.01), and LG-abdominal visceral fat area (beta = 0.12, p = 0.05). The association between SUA levels and markers of bone metabolism was dependent on the effect of confounders.

CONCLUSION

In postmenopausal osteoporotic women, the strong univariable association between SUA levels and femur BMD is partly explained by the confounding effect of indices of adiposity.

Serum uric acid is associated with lumbar spine bone mineral density in healthy Chinese males older than 50 years

Objectives

We aimed to investigate the association of serum uric acid (UA) levels with bone mineral density (BMD) at all skeletal sites in healthy Chinese males >50 years of age.

Methods

A cross-sectional study of 385 Chinese males >50 years of age who underwent health checkup in Huadong Hospital Affiliated to Fudan University in Shanghai, China, was conducted. Clinical and bone characteristics were compared in different UA tertiles (UA1: UA <4.7 mg/dL, UA2: 4.7 mg/dL ≤ UA <6 mg/dL and UA3: UA ≥6 mg/dL). Pearson correlation and multiple regression analysis were used to study the correlation of UA with BMD at various skeletal sites.

Results

Serum UA levels were positively associated with higher BMD and T-values at the lumbar spine, but not at other skeletal sites, after adjusting for multiple confounding factors. Lumbar spine BMD; the T- and Z-values at the lumbar spine, total hip and femoral neck; as well as intact parathyroid hormone (iPTH) levels are higher in the highest tertile of UA than in the second tertile of UA.

Conclusion

Our results provide epidemiological evidence in Chinese Han males aged >50 years that serum UA levels are positively correlated with lumbar spine BMD and T-values, suggesting that UA may exert protective effect on bone density at the lumbar spine in Chinese males >50 years of age.