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Gao B, Zhang C, Wang D, Li B, Shan Z, Teng W, Li J. Causal association between low vitamin D and polycystic ovary syndrome: a bidirectional mendelian randomization study. J Ovarian Res 2024; 17:95. [PMID: 38715063 PMCID: PMC11077756 DOI: 10.1186/s13048-024-01420-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/20/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Recent studies have revealed the correlation between serum vitamin D (VD) level and polycystic ovary syndrome (PCOS), but the causality and specific mechanisms remain uncertain. OBJECTIVE We aimed to investigate the cause-effect relationship between serum VD and PCOS, and the role of testosterone in the related pathological mechanisms. METHODS We assessed the causality between serum VD and PCOS by using genome-wide association studies (GWAS) data in a bidirectional two-sample Mendelian randomization (TS-MR) analysis. Subsequently, a MR mediation analysis was conducted to examine the mediating action of testosterone in the causality between serum VD and PCOS. Ultimately, we integrated GWAS data with cis-expression quantitative loci (cis-eQTLs) data for gene annotation, and used the potentially related genes for functional enrichment analysis to assess the involvement of testosterone and the potential mechanisms. RESULTS TS-MR analysis showed that individuals with lower level of serum VD were more likely to develop PCOS (OR = 0.750, 95% CI: 0.587-0.959, P = 0.022). MR mediation analysis uncovered indirect causal effect of serum VD level on the risk of PCOS via testosterone (OR = 0.983, 95% CI: 0.968-0.998, P = 0.025). Functional enrichment analysis showed that several pathways may be involved in the VD-testosterone-PCOS axis, such as steroid hormone biosynthesis and autophagy process. CONCLUSION Our findings suggest that genetically predicted lower serum VD level may cause a higher risk of developing PCOS, which may be mediated by increased testosterone production.
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Affiliation(s)
- Bingrui Gao
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
| | - Chenxi Zhang
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
| | - Deping Wang
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
- Department of Endocrinology and Metabolism, Hongqi Hospital Affiliated to Mudanjiang Medical College, Mudanjiang, Heilongjiang, 157011, P.R. China
| | - Bojuan Li
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
| | - Zhongyan Shan
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
| | - Weiping Teng
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China
| | - Jing Li
- Department of Endocrinology and Metabolism, The Institute of Endocrinology, NHC Key Laboratory of Diagnosis and Treatment of Thyroid Diseases, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, 110000, P.R. China.
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PCOS Physiopathology and Vitamin D Deficiency: Biological Insights and Perspectives for Treatment. J Clin Med 2022; 11:jcm11154509. [PMID: 35956124 PMCID: PMC9369478 DOI: 10.3390/jcm11154509] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 07/25/2022] [Accepted: 08/01/2022] [Indexed: 12/12/2022] Open
Abstract
Recent literature has stressed the importance of vitamin D (VD) in polycystic ovary syndrome (PCOS). Women with PCOS are deficient in VD, particularly those with a higher weight. Hypovitaminosis is a risk factor for glucose intolerance, and reduced levels of VD is associated with insulin resistance and increased diabetes risk. Since women with PCOS and hirsutism seem to have lower levels of VD than women with PCOS without hirsutism, a correlation between VD deficiency and hyperandrogenism may be suggested. Interestingly, VD is crucial for many human physiological functions, including to counteract inflammation and oxidative stress. Some studies evaluated effects of VD supplementation on glucose homeostasis variables, hormonal status, lipid concentrations, and biomarkers of inflammation and oxidative stress among VD-deficient women. Moreover, VD has been shown to play a role in egg quality and fertility. This review aims to show the relationship between VD and the endocrine and metabolic profile of PCOS patients, as well as its implications for their fertility. The supplement of VD to the common therapy can lead to an improvement of the insulin resistance and lipid metabolism, a reduction of circulating androgens, as well as a better response to the induction of ovulation in PCOS women.
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Shan C, Zhu YC, Yu J, Zhang Y, Wang YY, Lu N, Cai J, Liu W, Tao T. Low Serum 25-Hydroxyvitamin D Levels Are Associated With Hyperandrogenemia in Polycystic Ovary Syndrome: A Cross-Sectional Study. Front Endocrinol (Lausanne) 2022; 13:894935. [PMID: 35586624 PMCID: PMC9108253 DOI: 10.3389/fendo.2022.894935] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Increasing evidence suggests a link between vitamin D and polycystic ovary syndrome (PCOS). However, whether vitamin D is related to hyperandrogenemia in PCOS is still inconclusive. The aim of our study is to elucidate the relationship between vitamin D and hyperandrogenemia in women with PCOS in China. METHODS This is a cross-sectional study including 625 Chinese women with PCOS and 217 controls from January 2016 to June 2020. The anthropometric and biochemical parameters related to 25(OH)D, sex steroids, glucose and lipid profiles were measured. RESULTS Serum 25(OH)D levels were lower in women with PCOS than controls (33.99 ± 15.05 vs 36.58 ± 16.49 nmol/L, P = 0.034), especially lower in hyperandrogenic women with PCOS (32.79 ± 14.24 vs 36.21 ± 16.27 nmol/L, P = 0.007). Higher 25(OH)D levels were independently associated with lower risks of hyperandrogenemia after adjusting demographic, metabolic and hormonal confounders (OR = 0.982, 95% CI: 0.969 - 0.995, P = 0.006). Consistent results were observed in subgroup analyses. Among PCOS women with vitamin D deficiency, females with age ≥ 26 years had lower risks of hyperandrogenemia (OR = 0.611, 95% CI = 0.389 - 0.958, P = 0.032), while overweight patients had higher risks of hyperandrogenemia (OR = 2.202, 95% CI = 1.130 - 4.293, P = 0.020) after adjusting multiple confounders. CONCLUSIONS Our study reported lower vitamin D levels in Chinese women with PCOS, especially in those with hyperandrogenemia. An independent negative correlation between 25(OH)D and hyperandrogenemia was noted in PCOS. For PCOS women with vitamin D deficiency, females that have higher BMI with age < 26 years may be prioritized for hyperandrogenemia assessment.
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Helal BAF, Ismail GM, Nassar SE, Zeid AAA. Effect of vitamin D on experimental model of polycystic ovary syndrome in female rats. Life Sci 2021; 283:119558. [PMID: 33930367 DOI: 10.1016/j.lfs.2021.119558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/08/2021] [Accepted: 04/19/2021] [Indexed: 11/24/2022]
Abstract
AIMS Vitamin D plays an important role in the regulation of ovulatory dysfunction. We aimed to study the effect of vitamin D on letrozole-induced PCOS in female rats. MATERIAL & METHODS 40 non-pregnant Wistar rats were divided into four groups: group I control (received 1 ml of 1% aqueous solution of (CMC)/d orally), group II letrozole-induced PCOS group (received letrozole 200 μg/d orally), group III vitamin D-treated group (received vitamin D 1000 IU/kg/d), group IV letrozole and vitamin D treated group (received letrozole and vitamin D as group II and group III for 90 days. BMI, ovarian weight, serum vitamin D, biochemical metabolic and oxidative stress markers were evaluated, ovarian tissues glutathione, malondialdehyde levels and caspase-3 activity were measured. Histopathological examination of the ovary and coronary artery were done. KEY FINDINGS Letrozole-induced typical PCOS with significant decrease in vitamin D and coronary vasculopathy. Group II shows insignificant change in all parameters but there is significant increase in vitamin D and decrease in triglyceride and glutathione. In group VI all parameters were significantly improved but coronary vasculopathy was partly improved. Vitamin D was significantly negatively correlated with all parameters but significantly positively correlated with estradiol, insulin sensitivity, and HDL and insignificantly correlated with glutathione. Both Insulin resistance and testosterone were significantly positively correlated with all parameters but significantly negatively correlated with estradiol, insulin sensitivity, HDL and glutathione. SIGNIFICANCE These results holding the promise of beneficial impact of vitamin D administration to PCOS and its associated cardiovascular disorders.
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Safi A, Orazov M, Kalinchenko S. The role of cholecalciferol deficiency in the pathogenesis of polycystic ovary syndrome. ACTA ACUST UNITED AC 2020; 16:1745506520969606. [PMID: 33226913 PMCID: PMC7686588 DOI: 10.1177/1745506520969606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES to evaluate and compare clinical presentations, medical history, and laboratory data of patients with polycystic ovary syndrome, including vitamin 25(OH)D3 level. METHODS In total, 81 patients were examined. The patient group included 51 patients with signs of polycystic ovary syndrome. The control group included 30 healthy women without signs of polycystic ovary syndrome, comparable according to gender and age to the patient group. Polycystic ovary syndrome was verified based on the diagnostic Rotterdam and international polycystic ovary syndrome guidelines' criteria. The levels of cholecalciferol were determined by mass spectrometry (ng/mL). At the second stage of the study, the patient group with polycystic ovary syndrome was divided into two subgroups depending on the waist circumference and compared with each other by the level of insulin, low-density lipoproteins, triglycerides, anti-Mullerian hormone, follicle-stimulating hormone, and luteinizing hormone. Statistical analysis was carried out using the parametric t-test for two-independent samples with equal or different variance. For nominal data-Pearson's chi-test, when the means are not calculated and a test is carried out for the presence of a relationship between the nominal variables. RESULTS Patients with polycystic ovary syndrome and without polycystic ovary syndrome did not have a statistically significant difference in 25(OH)D3 level. Statistically significant differences in the level of 25(OH)D3 were found in women with polycystic ovary syndrome with the waist circumference ⩾80 cm. In these subgroups, differences in insulin, low-density lipoprotein, and triglycerides levels were also revealed. CONCLUSION The correlation of the 25(OH)D3 level does not differ in the groups of patients with polycystic ovary syndrome and without polycystic ovary syndrome, but significantly correlates with the metabolic profile of patients.
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Affiliation(s)
- Aigul Safi
- Department of Obstetrics and Gynecology with a Course in Perinatology, Institute of Medicine, People's Friendship University of Russia, Moscow, Russia.,"D-Doctor" Private Clinic, Nur-Sultan, Kazakhstan
| | - Mekan Orazov
- Department of Obstetrics and Gynecology with a Course in Perinatology, Institute of Medicine, People's Friendship University of Russia, Moscow, Russia
| | - Svetlana Kalinchenko
- Department of Endocrinology, Institute of Medicine, People's Friendship University of Russia, Moscow, Russia
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Arslan E, Gorkem U, Togrul C. Is There a Relationship Between Vitamin D Deficiency Status and PCOS in Infertile Women? Geburtshilfe Frauenheilkd 2019; 79:723-730. [PMID: 31303660 PMCID: PMC6620183 DOI: 10.1055/a-0871-6831] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 02/06/2019] [Accepted: 03/07/2019] [Indexed: 11/21/2022] Open
Abstract
Introduction
It is still unclear in the literature whether low vitamin D levels play a role in the pathogenesis of polycystic ovary syndrome (PCOS), especially with respect to the regulation of anti-Müllerian hormone (AMH). Therefore, we aimed to investigate whether there could be a relationship between vitamin D deficiency status and PCOS.
Materials and Methods
A total of 146 infertile women were divided into two groups according to their ovarian reserve patterns: (i) normal (NOR), and (ii) high (PCOS). The participants were also categorized into two groups according to vitamin D concentrations: (i) Group A < 10 ng/mL, and (ii) Group B 10 – 20 ng/mL. Samples were obtained and analyzed for estradiol (E2), follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone (TT), 17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone sulfate (DHEA-S) and AMH.
Results
In the NOR group, there were significant differences between Group A and Group B in terms of anthropometric characteristics (p < 0.05, for all). The women in both Group A and Group B had similar AMH concentrations (p > 0.005). Only the NOR group showed a significant though moderate negative correlation between 25(OH)D levels and anthropometric parameters. AMH levels were not correlated with 25(OH)D levels in the NOR or the PCOS group (r = − 0.112, p = 0.008; r = 0.027, p = 0.836). Multivariate regression analysis showed no impact of 25(OH)D on other study parameters. Only AMH measurements were significant enough (p < 0.001) to differentiate between PCOS and NOR patterns.
Conclusion
We found no difference in serum 25(OH)D and AMH levels between women with and women without PCOS. No correlation could be demonstrated between 25(OH)D and AMH in the PCOS group or controls.
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Affiliation(s)
- Emine Arslan
- Hitit University Faculty of Medicine, Department of Obstetrics and Gynecology, Corum, Turkey
| | - Umit Gorkem
- Hitit University Faculty of Medicine, Department of Obstetrics and Gynecology, Corum, Turkey
| | - Cihan Togrul
- Hitit University Faculty of Medicine, Department of Obstetrics and Gynecology, Corum, Turkey
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Bacopoulou F, Kolias E, Efthymiou V, Antonopoulos CN, Charmandari E. Vitamin D predictors in polycystic ovary syndrome: a meta-analysis. Eur J Clin Invest 2017; 47:746-755. [PMID: 28795765 DOI: 10.1111/eci.12800] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 08/07/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND The aim of this meta-analysis was to examine differences and predictors of serum 25-hydroxyvitamin D concentrations in women with polycystic ovary syndrome (PCOS) compared with non-PCOS controls matched for body mass index. MATERIALS AND METHODS Three databases were searched (2003-2015) to retrieve studies that evaluated serum 25-hydroxyvitamin D in PCOS women and controls. Meta-regression analysis was performed with anthropometric and metabolic/endocrine parameters as covariates. RESULTS Fourteen studies that included 2262 women (1150 PCOS patients/1162 controls) were eligible. Serum 25-hydroxyvitamin D, follicle-stimulating hormone and sex hormone-binding globulin were significantly lower in patients with PCOS than controls. Homoeostatic model assessment-insulin resistance index, serum insulin, total cholesterol, triglycerides, low-density lipoprotein cholesterol, luteinising hormone and testosterone were significantly higher in patients with PCOS compared to controls. Meta-regression analysis demonstrated significant effects of waist-to-hip ratio and glucose in PCOS women (β = -1·60, 95% CI: -2·30 to -0·90, P = 0·003; β = 0·20, 95% CI: 0·80-0·32, P = 0·004, respectively) and controls (β = -2·36, 95% CI: -3·38 to -1·33, P = 0·003; β = 0·11, 95% CI: 0·00-0·21, P = 0·05, respectively) and of total calcium and luteinising hormone in PCOS cases (β = 2·43, 95% CI: 1·67-3·19, P = 0·005; β = -0·37, 95% CI: -0·68 to -0·06, P = 0·03, respectively). CONCLUSIONS Serum 25-hydroxyvitamin D may be predicted positively by serum calcium and negatively by luteinising hormone in women with PCOS, and negatively by waist-to-hip ratio and positively by fasting glucose in both PCOS and non-PCOS women, independently of the presence of obesity.
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Affiliation(s)
- Flora Bacopoulou
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, 'Aghia Sophia' Children's Hospital, Athens, Greece
| | - Evangelia Kolias
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, 'Aghia Sophia' Children's Hospital, Athens, Greece
| | - Vasiliki Efthymiou
- Center for Adolescent Medicine and UNESCO Chair on Adolescent Health Care, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, 'Aghia Sophia' Children's Hospital, Athens, Greece
| | - Constantine N Antonopoulos
- Cardiovascular and Thoracic Surgery Department, General Hospital of Athens 'Evangelismos', Athens, Greece
| | - Evangelia Charmandari
- Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, School of Medicine, National and Kapodistrian University of Athens, 'Aghia Sophia Children's Hospital, Athens, Greece.,Division of Endocrinology and Metabolism, Clinical Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
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Mioni R, Cà AD, Turra J, Azzolini S, Xamin N, Bleve L, Maffei P, Vettor R, Fallo F. Hyperinsulinemia and obese phenotype differently influence blood pressure in young normotensive patients with polycystic ovary syndrome. Endocrine 2017; 55:625-634. [PMID: 27142411 DOI: 10.1007/s12020-016-0958-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 04/11/2016] [Indexed: 12/24/2022]
Abstract
To differentiate the impact of insulin levels/resistance per se from that of excess weight on blood pressure (BP) daily changes, we evaluated, using 24-h ambulatory blood pressure monitoring (ABPM), systolic blood pressure (SBP) and diastolic blood pressure (DBP) in a cohort of young normotensive patients affected by polycystic ovary syndrome (PCOS). A cross-sectional study was performed. Fifty-four patients were studied according to (a) insulinemic state: 32 hyperinsulinemic and/or insulin-resistant (h-INS) and 22 normoinsulinemic (n-INS) patients; and (b) body mass index (BMI): 22 obese (BMI > 30) and 32 lean (18.0 < BMI < 24.9) patients. Each subject's SBP and DBP and heart rate (HR) were measured by ABPM. Supine and upright plasma renin activity (PRA), and aldosterone levels were also assayed. Patients in the h-INS group showed higher 24-h, daytime, and nighttime diastolic blood pressure (DBP), higher nighttime systolic blood pressure (SBP) levels, as well as an increased 24-h, daytime and nighttime HR, compared to both obese and lean patients in the n-INS group. In relation to BMI, only 24-h, daytime, and nighttime DBP were higher in obese than in lean patients. At variance, when both h-INS and obesity were considered, 24-h SBP and DBP were higher in h-INS obese subjects than in the other groups. In multivariate analysis, insulin (max peak), area under the curve of insulin and insulin sensitivity index was independently associated with SBP. (1) Within a normotensive range, hyperinsulinemia and/or insulin resistance influence daily BP variation more than obesity does, suggesting a pivotal role of insulin on BP control in PCOS; (2) altered insulinemic state and ABPM-derived higher nighttime BP and HR may represent early markers to identify PCOS subjects prone to high cardiovascular risk.
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Affiliation(s)
- Roberto Mioni
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy.
| | - Anna Dalla Cà
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Jenni Turra
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Sara Azzolini
- Pediatric Endocrinology Unit - Department of Woman's and Child's Health, University of Padua, Padua, Italy
| | - Nadia Xamin
- Internal Medicine Unit - Civic Hospital, Bassano del Grappa (VI), Italy
| | - Luigi Bleve
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Pietro Maffei
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Roberto Vettor
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
| | - Francesco Fallo
- Clinica Medica 3 - Department of Medicine (DIMED), University of Padua, Via Giustiniani 2, 35128, Padua, Italy
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Jia XZ, Wang YM, Zhang N, Guo LN, Zhen XL, Li H, Wei L. Effect of vitamin D on clinical and biochemical parameters in polycystic ovary syndrome women: A meta-analysis. J Obstet Gynaecol Res 2015; 41:1791-802. [PMID: 26370491 DOI: 10.1111/jog.12793] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/23/2015] [Accepted: 06/01/2015] [Indexed: 02/06/2023]
Affiliation(s)
- Xin-Zhuan Jia
- Department of Reproductive Medicine; Fourth Hospital of Hebei Medical University; Shijiazhuang China
| | - Yong-Mei Wang
- Department of Obstetrics and Gynecology; Fourth Hospital of Hebei Medical University; Shijiazhuang China
| | - Na Zhang
- Department of Reproductive Medicine; Fourth Hospital of Hebei Medical University; Shijiazhuang China
| | - Li-Na Guo
- Department of Reproductive Medicine; Fourth Hospital of Hebei Medical University; Shijiazhuang China
| | - Xiu-Li Zhen
- Department of Reproductive Medicine; Fourth Hospital of Hebei Medical University; Shijiazhuang China
| | - Hui Li
- Department of Thoracic Surgery; Hebei Chest Hospital; Shijiazhuang China
| | - Lan Wei
- Department of Thoracic Surgery; Hebei Chest Hospital; Shijiazhuang China
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