[Retraction: Hydrogen alleviates collagen-induced arthritis (CIA) in mice by inhibiting IL-22 levels]

The retraction has been discussed after the authors asked to retract this article due to incorrect attribution and affillation of the authors.

[Short-term efficacy and safety of vedolizumab in patients with inflammatory bowel disease]

Objective: To evaluate the short-term efficacy and safety of vedolizumab in patients with inflammatory bowel disease (IBD). Methods: Patients with moderate and severe active IBD at the first use of vedolizumab from May 1 to October 31, 2021 were retrospectively enrolled. Then the clinical characteristics, and the efficacy and safety of vedolizumab were evaluated. Meanwhile, the clinical response rate, biological response rate and endoscopic response rate were calculated. Multivariate analysis was used to evaluate the independent influencing factors of short-term clinical efficacy and safety. Results: A total of 78 patients (44 males and 34 females) with IBD were enrolled, with a mean age of (40.5±11.9) years. The clinical remission rate, clinical response rate, biological remission rate, biological response rate and endoscopic remission rate was 60.3% (47/78), 85.9% (67/78), 70.5% (55/78), 43.6% (34/78) and 47.0% (31/66) respectively after 14 weeks of treatment. Body mass index (BMI) ≥ 18.5 kg/m² (HR=5.04, 95%CI: 1.50-16.91, P=0.009) and biological remission at 6 weeks of treatment (HR=15.22, 95%CI: 3.16-73.38, P=0.001) were predictors of endoscopic remission at 14 weeks of treatment. Adverse reactions occurred in 57 patients, with an incidence of 73.1%. The main manifestations were liver and kidney damage (37.2%) and infection (26.9%). Conclusions: More than half of patients with moderate and severe active IBD can achieve clinical remission after 14 weeks of vedolizumab treatment. Baseline BMI level and biological remission at 6 weeks of treatment are predictors of mucosal healing at 14 weeks. The incidence of adverse reactions is not low, although serious adverse reactions are rare in short-term treatment.

[The influence of gastroenterologists' intrinsic motivation on work burnout and the mediating effects of work stress]

Objective: To analyze the influence of intrinsic motivation on work burnout and the mediating effects of work stress. Methods: In 2020, questionnaire survey was conducted in 1 655 gastroenterologists working in 28 provinces of China. Mediation model was used to analyze the mediating effects of work stress in the relationship between intrinsic motivation and burnout. Resutls 1655 valid questionnaires were collected, including 1 132 women and 523 men, with an average age of 39.26. Intrinsic motivation was related to reduced level of burnout, including emotional exhaustion, dehumanization and low sense of accomplishment (β=-2.06, -1, 77 and-4.20;P<0.001). Job stress partially mediated the negative correlation between intrinsic motivation and job burnout in three dimensions, accounting for 40%, 15% and 5% (β=-1.58, -0.36 and-0.21;P<0.05), respectively. In female physicians, the intrinsic motivation was more directly related to the reduction of burnout, especially in the dimension"emotional exhaustion"(direct effect accounting for 62% in female gastroenterologists and 46% in male). Conclusions: Enhancing the intrinsic motivation of gastroenterologists can directly reduce burnout and indirectly reduce burnout by alleviating work stress. In the same work environment, female physicians' intrinsic motivation had a greater and more direct effect on reducing burnout.

[Effects of p16/pRb and JNK signaling pathways in hydroquinone-induced malignant transformation of TK6 cells]

Objective: To investigate the cell cycle and apoptosis in hydroquinone (HQ) -induced malignant transformation of TK6 cells and its related regulatory mechanisms. Methods: TK6 cells were exposed to 20 μmol/L HQ, 24 h/time, once a week, for 19 weeks as experimental group and TK6 cells treated with phosphate buffer (PBS) for 19 weeks was used as control group from March 2014. In regulatory mechanism research, the cells were divided into four groups: control group, experimental group, control inhibitor group and experimental inhibitor group (inhibitor groups were added 10 μmol/L P600125) . Cell cycle and apoptosis were detected by flow cytometry. The protein expression of cell cycle-related proteins and JNK signaling pathway proteins were detected by Western blot. Results: Flow cytometry showed that compared with control group, the ratio of cells in the G0/G1 phase of the experimental group was significantly decreased (P=0.001) , and the ratio of cells in the S phase was significantly increased (P=0.002) . Western blotting demonstrated that the protein expressions of p-Rb (Ser780) , E2F1, Cyclin D1, p-p16 (Ser152) , JNK1, p-JNK1 (Thr183/Tyr185) , c-jun, p-c-jun (Ser63) (P=0.015, 0.021, 0.001, 0.001, 0.005, 0.001, 0.039, 0.003) were up-regulated, while the protein expressions of Rb (P=0.048) and p16 (P=0.002) were significantly down-regulated. After exposed to SP600125, compared with experimental group, there were no significant changes in cell cycle distribution (P=0.946) and apoptosis rate (P=0.923) in experimental inhibitor group. The expression of c-jun (P=0.040) protein was down-regulated, while the expression of Rb (P=0.027) protein was up-regulated in experimental inhibitor group. Conclusion: In HQ-induced TK6 cells malignant transformation, the cell cycle is arrested in the S phase, and the p16/pRb signaling pathway is inhibited, while the JNK signaling pathway is activated. However, the activated JNK signaling pathway may not be involved in the regulation of cell cycle.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Long non-coding RNAs and small nucleolar RNA host gene 6 contribute to the depression-like behavior of hypothyroid mice by promoting methylation of the brain-derived neuropathic factor promoter that is mediated by DNA methyltransferase 1

Long non-coding RNAs (lncRNAs) and small nucleolar RNA host gene 6 (SNHG6) have attracted extensive attention due to their involvement in various pathological processes. However, the functional role of lncRNA SNHG6 in depression-like behavior induced by hypothyroidism is still largely unknown. Our study was designed to explore the biological role of lncRNA SNHG6 in depression-like behavior induced by hypothyroidism and the underlying mechanisms. First, the depression-like behavior of hypothyroid mice was investigated after lncRNA SNHG6 knockdown. Subsequently, the regulation of the methylation levels of the brain-derived neurotrophic factor (BDNF) promoters by lncRNA SNHG6 was evaluated. To reveal the underlying mechanisms of lncRNA SNHG6 in the methylation of the BDNF promoters, RNA pull-down assays, RNA immunoprecipitation, and co-immunoprecipitation were performed. Further experiments were also conducted to investigate the roles of DNA (cytosine-5)-methyltransferase 1 (DNMT1) in the depression-like behavior induced by hypothyroidism. In this study, elevated levels of lncRNA SNHG6 were noted in the hippocampus in hypothyroid mice. Function assays proved that lncRNA SNHG6 knockdown alleviated the depression-like behavior induced by hypothyroidism. Furthermore, a mechanistic investigation validated that lncRNA SNHG6 stabilized DNMT1 by blocking UHRF1-mediated DNMT1 ubiquitination, which increased the methylation levels of the BDNF promoters. Moreover, DNMT1 was found to be involved in depression-like behavior in hypothyroid mice. Our findings revealed a novel mechanism by which lncRNA SNHG6 promotes the methylation levels of the BDNF promoters by stabilizing DNMT1 and sheds light on potential therapeutic strategies for depression-like behavior induced by hypothyroidism.

Reference intervals of C2-C7 lateral spinous process deviation in Chinese adults

BACKGROUND

Lateral spinous process deviation (LSPD) is a commonly used morphological parameter in the anatomical study of the cervical spinous process. However, quantitative studies on this issue are still lacking. In this study we aimed to establish reference intervals of C2-C7 LSPD in the adult Chinese population and provide decision-making information for clinical practitioners.

MATERIALS AND METHODS

This was a retrospective study of 92 adult patients who received neck computed tomography scans, including 42 females and 50 males meeting the inclusion criteria. Three-dimensional reconstruction and anatomical measurements were performed using Mimics Research 19.0 and 3-Matic Research 11.0.

RESULTS

The inter-observer reliability of LSPD measurement in this study was excellent (intraclass correlation coefficient value > 0.93). Only 2 cases of LSPD angles of 90 degrees were found, which means most cervical spinous process exist deviation. The reference interval for the C2-C7 LSPD angle was (85.11, 94.75) degrees. The C2 LSPD showed the different directions to C5 and C7 (p < 0.05). In the C4 vertebrae, the male tends to have greater LSPD angles than the female (T = -2.013, p = 0.047). In the C2 vertebrae, there was a statistically significant but weak correlation between age and LSPD angles (r = 0.24, p = 0.029). There was no statistically significant effect of sex or age on other levels of cervical vertebrae.

CONCLUSIONS

Cervical spinous process deviation of less than 5 degrees on either side is a common morphological manifestation in Chinese adults. Thus, LSPD may not be an indicator for clinical care. Moreover, the vertebrae may have opposite directions of LSPD in the upper levels (C2-C4) and lower levels (C5-C7).

Morphological analysis of C2-C7 spinous process bifurcation in Chinese population: a study using three-dimensional reconstruction of computed tomography

BACKGROUND

This study aimed to investigate the anatomical morphology of the C2 to C7 spinous process (SP) bifurcation (SPB) in the Chinese population and reveal its potential clinical significance.

MATERIALS AND METHODS

Measurement parameters of the three-dimensional (3D) reconstructions of neck computed tomography scans (n = 92 scans) were retrospectively analysed. The 3D reconstruction and measurements were performed using Mimics Research 19.0 and 3-Matic Research 11.0. Two independent investigators reviewed all the data, including parameters such as the length and angle of the SPB. The effects of age and sex were also analysed.

RESULTS

We identified four morphological types of SPB: fully bifid (n = 252, 45.65%), partially bifid (n = 65, 11.78%), non-bifid (n = 226, 40.94%) and unilateral branch (n = 9, 1.63%). The Kappa coefficients indicated good inter-observer reproducibility (0.776), and the intraclass correlation coefficients (ICC) values demonstrated excellent intra-rater reliability (ICC = 0.9, p < 0.0001) in the classification and measurement of SPB parameters. The percentage of general bifid SP was more than 70% in C2-5 and about 21% in C6, while all C7 SPs presented non-bifid. Morphology was symmetrical in bifid and partially bifid SP, while unilateral SP was not.

CONCLUSIONS

The classification system of SPB in this study proved consistent and reliable, despite the subjective bias. Identifying the cervical level by C6 bifurcation is unreliable, as nearly 80% of C6 SP is non-bifid. Our work provides an accurate and effective anatomical reference for SPB studies in the Chinese population.

Accuracy of Models Fabricated by a Chair-side Fused Deposition Modeling (FDM) Printer in Stomatology

PURPOSE

To establish a method to improve the accuracy of a dental chair-side fused deposition modelling (FDM) printer and assess the internal adaptation of full crown casting patterns produced by the FDM printer.

METHOD

A Lingtong dental three-dimensional (3D) printer (Beijing SHINO Company, China), was used to fabricate six cubes. Deviation analysis was performed between the 3D scanned data and the designed cube data. Fifteen crowns (Group LT) of the right maxillary first molar were printed. A DDP 3D printer (Group EV) and a milling machine (Group ZT) were used to produce the same crowns as controls.

RESULTS

Compared with the designed cube, the 3D deviation of 73.75% points was within 0.1 mm. The calibration parameters (CP) of the X, Y, and Z directions were 1.005, 0.998, and 1.000, respectively. Based on the CP, the X and Y directions of the printer were adjusted in the software to compensate for the mechanical errors. The crowns were fabricated using different types of equipment to evaluate the accuracy of printing by the 3D dental printer. The internal gap of each crown was measured using a silicone replica and the 3D analysing method. In Group LT, the internal gap of the marginal, axial, and occlusal areas were 0.030 ± 0.019, 0.092 ± 0.019, and 0.023 ± 0.009 mm, respectively. In the marginal and occlusal areas, Group EV exhibited the smallest internal discrepancy, whereas in the axial area, Group ZT achieved the smallest. Only LT and ZT achieved internal spaces in the marginal area without statistical significance to the prescribed parameters (p>0.05).

CONCLUSION

The crown cannot be placed on the preparation if the printer is not calibrated. This study revealed the inability to produce full crown casting patterns with similar internal adaptations using different machines for fabrication. None of the three groups could reproduce the prescribed internal space. Combined with CAD/CAM technology, 3D printing technology has been gradually applied in stomatology.

Test of a multi-gigawatt, 800 ns high power microwave driver based on Marx generator and metal-oxide varistors

High power microwave (HPM) sources usually require a well-defined rectangular pulse waveform, which is especially true for the case of long pulse (>100 ns), stable, and high efficiency operation. Most long pulse HPM drivers are realized with pulse forming networks. This paper presents a long pulse driver composed of a conventional Marx generator and metal-oxide varistors (MOVs), utilizing the MOV's nonlinear V-I characteristic. This method is easy to implement, and it has an additional benefit that the voltage can be stabilized even if the load's impedance changes slightly. A low inductance zig-zag folding structure of the MOV is designed to decrease its size and self-inductance. An LC filter is used to reduce the energy loss in the MOV. In the experiment, a 400 kV, 800 ns long pulse is achieved at a foil-less electron diode, and longer than 300 ns HPM generation is obtained.

Data-driven nonlinear model reduction to spectral submanifolds in mechanical systems

While data-driven model reduction techniques are well-established for linearizable mechanical systems, general approaches to reducing nonlinearizable systems with multiple coexisting steady states have been unavailable. In this paper, we review such a data-driven nonlinear model reduction methodology based on spectral submanifolds. As input, this approach takes observations of unforced nonlinear oscillations to construct normal forms of the dynamics reduced to very low-dimensional invariant manifolds. These normal forms capture amplitude-dependent properties and are accurate enough to provide predictions for nonlinearizable system response under the additions of external forcing. We illustrate these results on examples from structural vibrations, featuring both synthetic and experimental data. This article is part of the theme issue 'Data-driven prediction in dynamical systems'.

Physical activity patterns, genetic susceptibility, and risk of hip/knee osteoarthritis: a prospective cohort study based on the UK Biobank

OBJECTIVES

The effect of physical activity on hip/knee osteoarthritis (OA) and how it varies by genetic susceptibility to OA remains inconclusive.

METHODS

In a cohort study of UK Biobank, 436,166 OA-free participants were recruited in 2006-2010 and followed for knee/hip OA until the end of 2020. 28 physical activity-related items were collected at baseline. Cox regression was used to estimate associations between physical activity behaviors, as well as major activity patterns (i.e., significant principal components[PCs] identified by principal component analysis), and risk of OA, adjusting for multiple confounders. We further stratified the analyses by polygenic risk score (PRS) for OA to examine the impact of genetic susceptibility to OA on the studied association.

RESULTS

During a mean follow-up of 11.15 years, 13,227 hip and 21,119 knee OA cases were identified. 19, out of 28, studied items showed associations with increased OA risk. Compared with low adherence group(<1^st tertile of PC score for each pattern), individuals with high adherence to five identified patterns were associated with increased risk of OA. The moderate adherence to "strenuous sports"(HR = 0.93, 95%CI: 0.89-0.97) and "walking for pleasure"(HR = 0.93, 95%CI: 0.89-0.98) patterns was associated with reduced OA. Similar risk patterns were obtained in the stratified analysis by PRS levels for OA.

CONCLUSION

High intensity of most activity patterns were associated with increased OA. However, a protective effect was suggested for moderate adherence to patterns of "strenuous sports" and "walking for pleasure" that consistent across different genetic susceptibilities, underscoring the potential benefits of moderate-intensity physical activity on OA.

Transcriptome dissection of candidate genes associated with lentil seed quality traits

Lentils provide a rich plant-based protein source and staple food in many parts of the world. Despite numerous nutritional benefits, lentil seeds also possess undesirable elements, such as anti-nutritional factors. Understanding the genetic networks of seed metabolism is of great importance for improving the seed nutritional profile. We applied RNA sequencing analysis to survey the transcriptome of developing lentil seeds and compared this with that of the pod shells and leaves. In total, we identified 2622 genes differentially expressed among the tissues examined. Genes preferentially expressed in seeds were enriched in the Gene Ontology (GO) terms associated with development, nitrogen and carbon (N/C) metabolism and lipid synthesis. We further categorized seed preferentially expressed genes based on their involvement in storage protein production, starch accumulation, lipid and suberin metabolism, phytate, saponin and phenylpropanoid biosynthesis. The availability of transcript profile datasets on lentil seed metabolism and a roadmap of candidate genes presented here will be of great value for breeding strategies towards further improvement of lentil seed quality traits.

[Preconception reproductive health and birth outcome cohort in Chongqing: the cohort profile]

Birth cohort is an important platform to study the effect of early-life exposure on health outcome, but large cohorts to investigate the effect of preconception exposure, especially paternal exposure, on reproductive health and birth outcome are limited. The Preconception Reproductive Health and Birth Outcome Cohort (PREBIC) is a prospective birth cohort study which pays equal attention to the contribution of environmental, psychological, behavioral as well as other factors to reproductive health and adverse birth outcomes in both men and women in Chongqing, China. PREBIC started in 2019 and plans to recruit 20 800 reproductive-age couples with child-bearing willingness. Followed up was conducted to understand the conception status of the women within two years. Women in pregnancy would be visited at first, second, third trimesters and after delivery. The offspring would be monitored until 2 years old to understand the incidences of preterm birth, low birth weight, birth defects, neurodevelopmental disorders and other outcomes. Related information and biospecimen collections (including semen, peripheral blood, urine, placenta, umbilical cord, cord blood and oral swab) were scheduled in each period. By January 2022, PREBIC had recruited 8 698 participants from all 38 districts in Chongqing. The goal of PREBIC is to establish one of the largest prospective preconception birth cohorts covering both men and women, which might provide a unique insight to understand the effects of the full reproductive cycle on reproductive health and adverse outcomes, with especial emphasis on preconception exposures.

Bone microarchitecture impairment in prolactinoma patients assessed by HR-pQCT

PURPOSE

Prolactinoma may reduce bone mineral density (BMD) and increase fracture risk, but its influence on bone microarchitecture remains to be elucidated. The purpose of this study is to evaluate bone microarchitecture parameters by high-resolution peripheral quantitative computed tomography (HR-pQCT) in prolactinoma patients.

METHODS

31 prolactinoma patients and 62 age- and sex-matched healthy controls in our center were included, and HR-pQCT was used to evaluate their bone microarchitecture at the radius and tibia. Z-scores for bone microarchitecture parameters were calculated based on previously published reference.

RESULTS

After adjusting for height and weight, prolactinoma patients had lower trabecular (- 0.011 mm, p = 0.005) and cortical thickness (- 0.116 mm, p = 0.008) and cortical area (- 6.0 mm2, p = 0.013) at radius, as well as lower trabecular (- 0.014 mm, p = 0.008) and cortical (- 0.122 mm, p = 0.022) thickness at tibia compared with the controls. Patients with higher prolactin level had more severe bone microarchitecture impairments. After adjusting for prolactin level and age, male patients had lower trabecular volumetric BMD (vBMD), trabecular number, trabecular thickness, and cortical porosity at radius, as well as lower trabecular vBMD, trabecular bone volume fraction, trabecular number, and cortical area, and higher trabecular separation at tibia compared with female patients. Z-score for radius vBMD was correlated with Z-score for areal BMD (aBMD) at lumbar and femoral neck, while Z-score for tibia vBMD was correlated with Z-score for lumbar aBMD, and some patients with vBMD Z-score below - 2.0 had aBMD Z-score within normal range.

CONCLUSION

Peripheral bone microarchitecture was impaired in prolactinoma patients, especially in patients with higher prolactin level. We compared the bone microarchitecture of prolactinoma patients and healthy controls by high-resolution peripheral quantitative computed tomography (HR-pQCT), and found that many bone microarchitecture parameters were impaired among prolactinoma patients. Such impairment was more prominent among patients with higher prolactin level.

A portrait of the Higgs boson by the CMS experiment ten years after the discovery

In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 gigaelectronvolts. Ten years later, and with the data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin-parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross-section for the production of a pair of Higgs bosons, on the basis of data from proton-proton collisions at a centre-of-mass energy of 13 teraelectronvolts. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.

P-355 Association between high serum uric acid level and adverse reproductive outcomes in infertile women with polycystic ovary syndrome

Study question

Does high serum uric acid (SUA) level affect the reproductive outcomes in women with polycystic ovary syndrome (PCOS) undergoing in-vitro fertilization (IVF)?

Summary answer

Elevated SUA is associated with decreased live birth rate, biochemical pregnancy rate and clinical pregnancy rate, and increased miscarriage rate in women with PCOS.

What is known already

SUA levelsand the prevalence of hyperuricemia (25.48%) are both significantly higher in women with PCOS than in women without PCOS (8.74%). SUA levels also can be used as a predictor of pregnancy complications (gestational diabetes mellitus and hypertensive disorders of pregnancy) and adverse foetal outcomes (preterm birth and low birth weight).

Study design, size, duration

This retrospective cohort study was conducted ininfertile women with PCOS between September 2012 and December 2019.

Participants/materials, setting, methods

A total of 1,032 infertile PCOS women undergoing their first IVF/ICSI cycle were observed. Data of reproductive outcomes including live birth rate, biochemical pregnancy rate, clinical pregnancy rate, and miscarriage rate were analyzed according to the quartile groups of SUA levels.

Main results and the role of chance

In quartiles of SUA levels, there was a significant decreasing trend in live birth rate from the lowest quartile (Q1: 34.5%) to the highest (Q4: 19.2%) (Pfor trend &lt;0.001). Notably, the miscarriage rate in Q4 was significantly higher than that in the other 3 quartiles (all P values &lt; 0.05). From Q1 to Q4, the incidence of miscarriage dramatically increased from 15.5% to 31.0% (Pfor trend &lt;0.05). In addition, the biochemical pregnancy rate and clinical pregnancy rate decreased significantly from the lowest quartile to the highest (Pfor trend &lt;0.05). With the first quartile of uric acid as the reference group, the logistic regression analysis showed that in both unadjusted and adjusted models, elevated SUA level was associated with significantly lower probabilities of live birth, biochemical pregnancy, and clinical pregnancy, and a higher risk of miscarriage in a linear fashion (all Pfor trend&lt; 0.05).

Limitations, reasons for caution

This study is limited by its retrospective design. It was difficult to ensure consistency in clinical practice among the physicians.

Wider implications of the findings

Our study suggeststhat clinical physicians need to pay close attention to PCOS women with high SUA levelsbefore IVF treatment. Prospective studies to determine an appropriate range of lower-SUA levels prior to treatment is necessary to support our findings.

Trial registration number

not applicable