Association Between Serum Uric Acid Levels and Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis of Observational Studies

No Association Found Between Uric Acid Levels and Peripheral Vertigo Disorders: Results From a Two-Sample Mendelian Randomization Study

BACKGROUND

The association between serum uric acid levels and peripheral vertigo diseases, namely Benign Paroxysmal Positional Vertigo (BPPV), Meniere's Disease (MD), and Vestibular Neuritis (VN), remains a subject of controversy. This study utilises the Mendelian Randomization (MR) approach to investigate the potential link between uric acid levels and these peripheral vertigo diseases, with the goal of informing preventative measures and early intervention strategies.

METHODS

Datasets pertaining to uric acid levels (sample size = 343 836) and BPPV (ncase = 3834, ncontrol = 209 582), MD (ncase = 1511, ncontrol = 209 582), and VN (ncase = 1224, ncontrol = 209 582) were selected from Genome-Wide Association Studies (GWAS). Two-sample MR was employed to analyse the correlation between the exposure (uric acid levels) and outcomes (BPPV, MD, VN). The MR analysis methods encompassed Inverse Variance Weighting (IVW), MR-Egger, Simple Mode, Weighted Mode, and Weighted Median methods. The results derived from the IVW analysis were considered as the primary analytical outcomes.

RESULT

The findings indicated no significant correlation between uric acid levels and BPPV (IVW: OR = 1.152, 95% CI: 0.971-1.367, p = 0.103), MD (IVW: OR = 1.010, 95% CI: 0.757-1.348, p = 0.943), and VN (IVW: OR = 1.005, 95% CI: 0.744-1.358, p = 0.969).

CONCLUSION

This study employed a two-sample Mendelian randomization approach to conduct an in-depth analysis of the relationship between serum uric acid levels and peripheral vestibular diseases (BPPV, MD, and VN). Our findings indicate that no significant association was found between serum uric acid levels and these diseases. The results of the study do not support the hypothesis that uric acid is an independent risk factor for these conditions.

Development and verification of a nomogram for recurrence risk of Benign Paroxysmal Positional Vertigo in middle-aged and older populations

Background

Benign Paroxysmal Positional Vertigo (BPPV) is the most common cause of peripheral vertigo, with frequent recurrence, particularly pronounced among middle-aged and elderly populations, significantly affecting patients' quality of life. This study aimed to identify predictive factors for recurrence in middle-aged and older patients with BPPV and to develop a nomogram prediction model based on these predictors.

Methods

This retrospective study included 582 participants aged ≥45 years who were selected from the electronic medical records system of the First Hospital of Changsha between March 2021 and March 2024. Randomly chosen participants (n = 407, 70%) constituted the training group, whereas the remaining participants (n = 175, 30%) formed the validation group. This study used LASSO binomial regression to select the most predictive variables. A predictor-based nomogram was developed to calculate the risk of BPPV recurrence. The performance of the nomogram was evaluated using the area under the receiver operating characteristic curve (AUC) and calibration curves with 1,000 bootstrap resampling validations. Decision curve analysis (DCA) was conducted to assess the clinical usefulness of the nomogram.

Results

According to findings from least absolute shrinkage and selection operator (LASSO) binomial regression and logistic regression screening, older age, higher levels of uric acid (UA) and homocysteine (HCY), diabetes, migraine, anxiety, and insomnia were identified as independent factors associated with an increased recurrence risk of BPPV. A nomogram model for predicting recurrence risk was developed based on these predictors. The nomogram achieved an AUC (C-statistic) of 0.8974 (95% CI: 0.8603-0.9345) in the training group and 0.8829 (95% CI: 0.8253-0.9406) in the validation group. Calibration curves, after 1,000 bootstrap resamples, demonstrated good agreement between the predicted and actual probabilities in the development and validation cohorts. DCA indicated that the nomogram had clinical utility.

Conclusion

The nomogram model incorporating age, UA, HCY, diabetes, migraine, anxiety status, and insomnia demonstrated a strong predictive capability for estimating the probability of BPPV recurrence in middle-aged and elderly patients. This tool is valuable for identifying individuals at high risk of BPPV recurrence and can aid physicians in making informed treatment decisions aimed at reducing recurrence rates.

Risk Factors for Recurrence of Benign Paroxysmal Positional Vertigo: A Prospective Study

OBJECTIVES

Benign paroxysmal positional vertigo (BPPV) can be treated successfully in most cases. However, recurrences are common. We aimed to prospectively investigate demographic and clinical risk factors for BPPV recurrence. Our second aim was to investigate whether seasonality affects recurrences.

METHODS

We recruited adult Dutch patients presenting at our dizziness clinic with a diagnosis of definite or possible BPPV for a prospective observational study with 1-year follow-up. Factors collected from patient history and questionnaires were age, sex, ethnicity, previous treatment for BPPV, duration of BPPV symptoms, number of treatment sessions for the initial BPPV episode, the affected canal, recent head trauma, and a history of vestibular neuritis, Menière's disease, (vestibular) migraine, gout, diabetes mellitus, and chronic renal failure. Factors derived from blood samples were uric acid, glycated hemoglobin, and 25-hydroxyvitamin D.

RESULTS

We included 139 subjects with a mean age of 65 (SD, 13) years, of whom 70% was female. A total of 48 subjects (34.5%) suffered from at least one recurrence during the 1-year follow-up. Independent risk factors for recurrence of BPPV were "multiple treatment sessions for the initial BPPV episode" (incidence rate ratio, 1.74; 95% confidence interval 1.06-2.85; p = 0.027) and history of gout (incidence rate ratio, 1.90; 95% confidence interval, 1.01-3.57; p = 0.045).

CONCLUSION

One-third of patients presenting in a tertiary dizziness clinic develop at least one recurrence of BPPV within 1 year. Multiple treatment sessions and a history of gout are independent risk factors for recurrence.

Exploring the Association of Serum Uric Acid Levels with Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis

Objectives: The role of uric acid in pathogenesis of benign paroxysmal positional vertigo (BPPV) is not fully understood. It is aimed to assess the serum uric acid levels in BPPV patients compared to healthy controls. Study design: Systematic review and meta-analysis. Methods: Web of science, PubMed, Scopus, Google Scholar, Embase, Medline, and Cochrane library were systematically searched. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Problem/Population, Intervention, Comparison, and Outcome (PICO) guidelines were used. Results: In total, 20 studies including 3967 participants met the inclusion criteria. Ten studies (50%) reported higher uric acid (UA) levels in BPPV patients, 4 studies (20%) indicated lower UA levels in BPPV patients, while 6 studies (30%) found no significant difference in UA levels between BPPV patients and healthy controls. The overall mean serum levels of UA (SMD: 0.265, [-0.163 to 0.693]) were higher in BPPV patients than control group. However, this difference was not statistically significant (P-value: .225). Conclusion: There is no significant difference in serum level of UA between BPPV patients and healthy controls. It means that serum level of UA (whether low or high) is not likely the underlying factor of development of BPPV.

Association between Benign Paroxysmal Positional Vertigo and Thyroid Diseases: Systematic Review and Meta-Analysis

Introduction  Benign paroxysmal positional vertigo (BPPV) is the peripheral vestibular dysfunction that most affects people worldwide, but its etiopathogenesis is still not fully understood. Considering the etiological diversity, some studies highlight the association between BPPV and thyroid diseases. Objective  To investigate the association between thyroid diseases and BPPV. Data Synthesis  Systematic review and meta-analysis of epidemiological studies searched in the PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases. Studies that were fully available and investigated the association between BPPV and thyroid diseases were selected. The articles that composed the meta-analysis were analyzed using the dichotomous model, the Mantel-Haenszel statistical test, odds ratio (OR), and a 95% confidence interval (CI). Of the 67 articles retrieved from the databases, 7 met the eligibility criteria of the systematic review, and 4 had data necessary to perform the meta-analysis. Qualitative analysis revealed that the studies were conducted in the European and Asian continents. The predominant methodological design was the case-control type, and thyroid dysfunctions, hypothyroidism, and Hashimoto thyroiditis occurred more frequently. The meta-analysis showed no association between hypothyroidism and BPPV; however, there was a statistically significant relationship between Hashimoto thyroiditis and BPPV. Conclusion  The meta-analysis results suggest a possible association between BPPV and Hashimoto thyroiditis. Nevertheless, we emphasize the need for further studies to elucidate the evidence obtained.

Low vitamin D and uric acid status in patients with benign paroxysmal positional vertigo

PURPOSE

Growing evidence reported that vitamin D and uric acid metabolism played roles in the occurrence of benign paroxysmal positional vertigo, an otoconia-related vestibular disorder. We aimed to investigate the serum 25-hydroxy vitamin D (25(OH)D) and uric acid in patients with benign paroxysmal positional vertigo and to determine the risk factor for benign paroxysmal positional vertigo.

METHODS

This case-control study comprised 182 patients with benign paroxysmal positional vertigo and 182 age- and gender-matched controls. All subjects' age, body mass index, systolic blood pressure, diastolic blood pressure, 25-hydroxyvitamin D (25(OH)D), uric acid and serum calcium measurements were analyzed.

RESULTS

We found a female preponderance of benign paroxysmal positional vertigo patients, with a median of 60 (52-66) years old. The results showed low vitamin D status both in benign paroxysmal positional vertigo and controls, with no significant difference of 25(OH)D levels between benign paroxysmal positional vertigo patients and controls (P > 0.05). Compared with the control group, patients with benign paroxysmal positional vertigo had a higher prevalence of vitamin D deficiency and a lower prevalence of vitamin D sufficiency (P < 0.05). Uric acid was significantly lower in the benign paroxysmal positional vertigo groups (P < 0.05). Logistic regression analysis revealed that age and uric acid were considered higher risk predictors for benign paroxysmal positional vertigo.

CONCLUSION

Our study observed low vitamin D status in patients with benign paroxysmal positional vertigo, with no significant differences of the 25(OH)D level in patients with benign paroxysmal positional vertigo and controls. Elderly, vitamin D deficiency and low uric acid levels may be risk factors for benign paroxysmal positional vertigo occurrence.

Recurring benign paroxysmal positional vertigo after successful canalith repositioning manoeuvers

Benign baroxysmal positional vertigo (BPPV) represents the most common peripheral vestibular dysfunction encountered in clinical practice. Although canalith repositioning procedures (CRPs) are a relatively successful treatment for BPPV, many patients suffer from recurrences. Several studies have demonstrated that various pathological conditions (diabetes, hypertension, endolymphatic hydrops, low vitamin D levels) as well as delayed BPPV treatment using CRP, multiple canal involvement may be associated with recurrence of BPPV. We evaluated the history of 1,428 patients (558 males and 870 females, age range 10-92 years) suffering from BPPV. Of 1,428 cases, 820 (77%) did not relapse in the following 20 years. Mean age and gender did not differ significantly between groups with and without recurrence. Regarding risk factors for BPPV recurrence, age, female gender, migraine, hypertension, diabetes mellitus, hyperlipidaemia, osteoporosis, vascular diseases, and vitamin D deficiency may be associated with recurrent BPPV and should be kept in mind. Osteoporosis, vitamin D deficiency as well as thyroid dysfunction should be evaluated in postmenopausal women. Treatment of these comorbidities may help to reduce the risk of BPPV recurrence.

Transcranial Sonography as a Diagnostic Tool for Depressive Disorders

BACKGROUND

Transcranial sonography (TCS) is an available and noninvasive neuroimaging method that has been found to reduce the echogenicity of the brainstem raphe (BR) in patients with depression. Applying the criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV), we performed a meta-analysis of the diagnostic accuracy of TCS.

METHODS

A systematic search was conducted in PubMed, EMBASE, The Cochrane Library, and Web of Science. The databases were searched from inception to December 2021. The quality of the included literature was assessed using the QUADAS-2. Heterogeneity analysis was performed. A summary receiver operating characteristic (SROC) curve was generated to evaluate the diagnostic accuracy of TCS.

RESULTS

We included 12 studies with 809 patients. The pooled sensitivity was 0.66 (95% confidence interval [CI]: 0.61-0.71), and the specificity was 0.84 (95% CI: 0.80-0.87). The combined positive likelihood ratio (LR) was 3.84 (95% CI: 2.68-5.51), the negative LR was 0.41 (95% CI: 0.29-0.57), and the diagnostic odds ratio (DOR) was 11.45 (95% CI: 5.57-23.02). The area under the curve (AUC) of the plotted SROC curve was 0.86 (95% CI: 0.83-0.89). The meta-regression and subgroup analyses found no source of heterogeneity.

CONCLUSION

TCS has high potential and efficacy in diagnosing depression and may be a reasonable test to perform clinically for the assessment of depression.

The Risk of BPPV, Meniere's Disease, and Vestibular Neuronitis in Patients with Gout: A Longitudinal Follow-Up Study Using a National Health Screening Cohort

This study evaluated the impact of pre-existing gout on the occurrence of benign paroxysmal positional vertigo (BPPV), Meniere’s disease, and vestibular neuronitis, with the goal of identifying novel associations of gout with other comorbid diseases. The 2002−2019 Korean National Health Insurance Service Health Screening Cohort data were retrospectively analyzed. 23,827 patients with gout were matched to 95,268 controls without gout for age, sex, income, region of residence, and index date. The occurrence of BPPV, Meniere’s disease, and vestibular neuronitis was evaluated in both groups. The hazard ratios (HRs) of gout for BPPV, Meniere’s disease, and vestibular neuronitis were calculated using a stratified Cox proportional hazard model. Participants with gout demonstrated a 1.13-fold higher risk of BPPV (95% CI, 1.06−1.21, p < 0.001) and a 1.15-fold higher risk of Meniere’s disease (95% CI, 1.15−1.37, p < 0.001) than the matched control group. However, the HR for vestibular neuronitis was not significantly higher in the gout group (adjusted HR = 1.06, 95% CI, 0.93−1.21, p = 0.391). A previous history of gout was related to a higher risk of BPPV and Meniere’s disease. Additional studies are necessary to elucidate the mechanism underlying the relationship between gout and comorbid diseases such as BPPV and Meniere’s disease.

Early Versus Late Tracheostomy in Stroke Patients: A Retrospective Analysis

OBJECTIVE

The timing of tracheostomy (TR) in severe stroke patients receiving mechanical ventilation has not been determined. In this study, we compared some prognostic indicators of early tracheostomy (ET) and late tracheostomy (LT). A meta-analysis was performed to obtain a higher level of evidence of the timing of TR in patients with severe stroke receiving mechanical ventilation.

METHODS

The study was a retrospective single-center study. We divided the severe stroke patients who received TR from June 2020 to June 2022 into the ET group and LT group. The demographic characteristics, clinical characteristics and prognostic indices were compared. For this meta-analysis, we systematically searched PubMed and other databases. The compared prognostic indicators included mechanical ventilation time, ICU length of stay (LOS), total LOS, ventilator-related pneumonia (VAP) incidence, and mortality.

RESULTS

A total of 61 patients were included in our study, including 32 patients in the ET group and 29 patients in the LT group. Univariate and multivariate analyses showed that the NIHSS score in the ET group was higher than that in the LT group (P < 0.05). In terms of outcome indicators, compared with the LT group, the median mechanical ventilation time in the ET group was shortened by 5.5 days (P = 0.034). The ICU LOS and total LOS in the ET group were significantly lower than those in the LT group (median 14.5 days vs 22 days, P = 0.004; 21 days vs 27 days, P = 0.019). The meta-analysis showed that ET could significantly shorten the ICU LOS (MD -3.89 [95% CI: -6.86, -0.92]) and the total LOS (MD -7.70 [95% CI: -8.57, -6.83]) and significantly reduce the occurrence of VAP (OR 0.75 [95% CI: 0.64, 0.87]).

CONCLUSION

The results of our retrospective study and meta-analysis support that ET can shorten the ICU LOS and total LOS and reduce the occurrence of VAP. Therefore, it has a positive effect on the prognosis of patients with severe stroke who need mechanical ventilation support.

Efficacy and safety of massage in the treatment of poststroke depression: A systematic review and meta-analysis of protocols

BACKGROUND

Poststroke depression (PSD) is a severe problem; it will significantly increase the mortality of patients after stroke, and affect the quality of life of patients after discharge. For stroke patients without noticeable adverse reactions, massage can effectively improve the patient's mood, thereby treating poststroke depression. But so far, there is still no systematic research to provide reliable evidence that massage can effectively treat poststroke depression. Therefore, the purpose of this study is to comprehensively summarize and evaluate the effectiveness and safety of massage therapy for poststroke depression.

METHODS

We conduct a detailed search regardless of publication grade and language status. The search databases include the Web of Science, the Cochrane Library search, EMBASE, PubMed, CNKI, Chinese biomedical literature database, Chongqing VIP, and Wanfang. All randomized controlled trials and cohort studies on massage therapy for poststroke depression are published, as of November 15, 2020. The team consists of 2 experienced researchers who will select the retrieved documents and extract data. Later they used RevMan V.5.3 software for data analysis and data synthesis.

RESULTS

The effectiveness and safety of massage therapy intended for poststroke depression will be subject to a systematic evaluation under this program.

CONCLUSION

It will be substantiated in this review whether massage therapy is a reliable intervention for poststroke depression by examining the evidence collected.

INPLASY REGISTRATION NUMBER

INPLASY2020110085.

Low Antioxidant Status of Serum Uric Acid, Bilirubin, Albumin, and Creatinine in Patients With Benign Paroxysmal Positional Vertigo

Objective: To investigate the roles of serum uric acid (UA), bilirubin (BIL), albumin (ALB), and creatinine (CRE) as major intravascular antioxidants, in benign paroxysmal positional vertigo (BPPV).

Methods: The serum levels of UA, BIL, ALB, and CRE were retrospectively analyzed in 70 patients with new-onset idiopathic BPPV and 140 age- and sex-matched healthy controls (HCs).

Results: Serum UA, BIL, ALB, and CRE levels were significantly lower in the BPPV group than the HC group. Furthermore, serum levels of BIL and ALB were significantly lower in the BPPV group when compared by sex. Multiple stepwise logistic regression revealed that a reduction in serum ALB was independently related to BPPV (odds ratio = 0.688; 95% confidence interval = 0.607– 0.780). Receiver operating characteristic analyses revealed a cut-off value of 45.15 g/L for ALB with a sensitivity of 74.29% (62.97– 83.07%) and specificity of 73.57% (65.71– 80.18%).

Conclusions: Serum levels of UA, BIL, ALB, and CRE were lower in BPPV patients, indicating a lower antioxidant status. Furthermore, a reduction in serum ALB was independently associated with BPPV. These results provide insights into the possible roles of oxidative stress in the pathogenesis of BPPV.

The management of gout in Africa: challenges and opportunities

The rise in non-communicable diseases in Africa presents challenges for health systems that are burdened by infectious diseases. Gout is one of those diseases that has seen an increase in numbers worldwide, including Africa. Gout is commonly associated with comorbidities and mortality. It directly impacts the quality of life, increases health costs, decreases physical function, and significantly increases the time from work, much of which is potentially avoided if treatment is instituted early. Despite advances in understanding the pathophysiology and outcomes of gout, the quality of care delivered to patients in Africa is still suboptimal. Existing data on gout in Africa reveals a general low index of suspicion due to limited knowledge of the disease by healthcare workers resulting in late diagnosis, with severe polyarticular tophaceous gout being a common presenting feature. These late presentations are associated with avoidable disability and increase the direct and indirect costs of managing gout. The challenges are related to lack of government budgetary support for staff training, infrastructure for diagnosis, and availing medicines. The picture of gout in Africa largely mirrors the west concerning risk factors, comorbidities, and burden of disease, but with some unique presentations seen in HIV, sickle cell disease, and vertigo. We discuss the challenges of gout diagnosis and management in Africa and propose a roadmap to improve gout outcomes across Africa.

Risk Factors for the Recurrence of Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis

OBJECTIVE

Benign paroxysmal positional vertigo (BPPV) has a high recurrence rate, but the risk factor-associated recurrence are elusive.

METHODS

Searches were performed in PubMed, Embase, Cochrane library, Web of science, Chinese National Knowledge Infrastructure, and Sino Med up to November 3, 2019. The effect size was analyzed by odds ratio and 95% CI. Data from eligible studies were meta-analyzed using Stata version 15.0.

RESULTS

Our search resulted in a total of 4076 hits. Twenty-four outcomes of sixty articles were included in the meta-analysis. Risk factors for the recurrence of BPPV included female gender, age (≥65years), hyperlipidemia, diabetes, hypertension, migraine, cervical spondylosis, osteopenia/osteoporosis, head trauma, otitis media, abnormal vestibular evoked myogenic potential, and long use of computers. No significant differences were found in side, type of the involved semicircular canals, smoking, alcohol consumption, stroke, ear surgery, duration of vertigo before treatment, the times of repositioning, Meniere disease, sleep disorders, hypercholesterolemia, and 25-hydroxy vitamin D.

CONCLUSION

These findings strengthen clinical awareness of early warning to identify patients with potential relapse risk of BPPV and clinicians should counsel patients regarding the importance of follow-up after diagnosis of BPPV.

Evaluation of serum uric levels in migraine

OBJECTIVE

In our study, the aim was to identify the serum uric acid levels, a marker of oxidative stress, according to migraine subtypes (aura/without aura and episodic/chronic migraine).

METHOD

The study included 300 migraine patients and 150 healthy controls for a total of 450 individuals. Migraine and subtypes were diagnosed according to International Classification of Headache Disorders-2013 criteria. Patients were evaluated during attendance at the neurology clinic.

RESULTS

Our patient group was 77.0% female and disease duration was 9.2 ± 7.2 years. Our control group comprised 77.3% females. The age intervals in the patient and control groups were 36.4 ± 10.4 years and 36.0 ± 8.1 years. There was no statistically significant difference between our control and patient groups in terms of age and gender (p = .937 and p = .655). The serum UA, ferritin, and urea levels in our patient group were found to be significantly low compared to the healthy control group (p < .001). The serum UA levels in the migraine and control groups were 3.7 ± 0.7 and 4.6 ± 0.7 mg/dL, respectively (p < .001). There were no statistically significant differences observed between serum uric acid levels and other blood parameters between aura/without aura and episodic/chronic migraine subtypes (p > .05).

CONCLUSION

Our study supports the hypothesis that the oxidative stress marker of serum uric acid levels may be associated with migraine diagnosis, concluding that serum uric acid levels were not significant for migraine subtypes.

Increased Otolin-1 in Serum as a Potential Biomarker for Idiopathic Benign Paroxysmal Positional Vertigo Episodes

Objective: Otolin-1, a main specific otoconia matrix protein, passes through the labyrinth-blood barrier and is detectable in peripheral blood. Serum otolin-1 levels differ between patients with benign paroxysmal positional vertigo (BPPV) and healthy controls and are significantly age-related, increasing in healthy controls with age, suggesting that serum otolin-1 levels reflect otolith status. The aim of this study was to determine whether otolin-1 levels change during vertigo episodes in patients with BPPV and whether any change is specific and sensitive enough for BPPV episodes.

Method: Patients diagnosed with de novo idiopathic BPPV during an acute episode were included in the study from May 2017 to May 2018. Blood samples were drawn before patients were treated with canalith-repositioning maneuvers. Serum otolin-1 levels were compared between 78 patients and 121 age- and sex-matched healthy individuals.

Results: There were no significant differences between the groups in the age distribution, sex ratio, body mass index, clinical history, routine blood parameters, or total protein, albumin, uric acid, creatinine, blood urea nitrogen and lipid profiles (P > 0.05). Serum levels of otolin-1 were significantly higher in BPPV patients than in healthy controls (P < 0.001). Receiver operating characteristic analysis revealed that a serum otolin-1 value of 299.45 pg/ml was the optimal cut-off value to discriminate patients with BPPV from healthy controls (area under the curve 0.757, 95% CI 0.687~0.826) with a sensitivity of 67.9% and a specificity of 72.7%.

Conclusion: Serum levels of otolin-1 may be a potential biomarker for BPPV episodes.

Retrospective Analysis of the Correlation between Uric Acid and Thyroid Hormone in People with Normal Thyroid Function

OBJECTIVE

This study adopts the method of retrospective analysis to collect general information and laboratory results of physical examination population, hoping to clarify the correlation between uric acid and thyroid hormone.

METHODS

The subjects of the study were healthy subjects who underwent physical examination at the Sir Run Run Shaw Hospital affiliated to the Medical College of Zhejiang University from January 2016 to December 2018. Demographic information and medical history of all subjects were recorded through an electronic health system. Serum uric acid (SUA) was grouped by quartiles. Statistical analyses were performed with R version 3.5.1.

RESULTS

A total of 48,526 subjects were included in the analysis. Gender ratio, age, BMI, waist circumference, systolic blood pressure, diastolic blood pressure, FBG, HbA1c, TG, HDL-C, ALT, AST, FT3, FT4, and TSH were significantly different among the uric acid groups. The regression coefficients of SUA in the TSH, FT3, and FT4 regression models were B = 1.000 (95% CI 1.000-1.000, p = 0.009), B = 0.999 (95% CI 0.999-0.999, p < 0.001), and B = 1.001 (95% CI 1.001-1.001,  p < 0.001), respectively. There was a significant dose-dependent relationship between FT4, FT3, and SUA gradient.

CONCLUSIONS

Under normal thyroid function, there were significant differences in TSH, FT3, and FT4 between groups with different uric acid levels. Uric acid levels were linearly correlated with FT3 and FT4, but not with TSH.