Objective To explore the effect of rehmanniae radix extract(RRE)on chondrocyte apoptosis in the rabbit model of knee osteoarthritis(KOA)by regulating the miR-485-5p/heat shock protein 90 beta family member 1(Hsp90b1)axis.Methods New Zealand rabbits were randomly assigned into control,KOA,low-dose RRE,medium-dose RRE,high-dose RRE,celecoxib,high-dose RRE+antagonist control,and high-dose RRE+miR-485-5p antagonist groups,with 12 rabbits in each group.Rabbits in other groups except the control group were modeled for KOA with the improved Hulth method.After modeling for 8 weeks,the rabbits were administrated with corresponding agents for 4 weeks.The changes in the activity rating of rabbits were recorded.ELISA was employed to measure the levels of tumor necrosis factor-α(TNF-α)and interleukin(IL)-6 in the serum.Safranine O-fast green staining was conducted to reveal the pathological changes in the cartilage tissue and Mankin scoring was performed.TUNEL was employed to detect chondrocyte apoptosis.Real-time fluorescence quantitative PCR was performed to determine the expression of miR-485-5p in the cartilage tissue.Western blot was employed to determine the protein levels of Hsp90b1,cleaved cysteinyl aspartate-specific proteinase-3(Caspase-3),and Bcl2-associated-X(Bax)in the cartilage tissue.The dual-luciferase reporter assay was employed to examine the relationship between miR-485-5p and Hsp90b1.Results Compared with the control group,the KOA group showed down-regulated expression of miR-485-5p,elevated levels of TNF-α and IL-6 in the serum,cartilage erosion and losses,and increases in activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.001).Compared with the KOA group,RRE at low,medium,and high doses,and celecoxib up-regulated the expression of miR-485-5p,lowered the levels of TNF-α and IL-6 in the serum,alleviated the pathological damage to the cartilage tissue,and decreased the activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.05).Compared with the high-dose RRE group and the high-dose RRE+antagonist control group,high-dose RRE+miR-485-5p antagonist down-regulated the expression of miR-485-5p,elevated the levels of TNF-α and IL-6 in the serum,exacerbated the pathological damage to the cartilage tissue,and increased the activity rating,Mankin score,chondrocyte apoptosis rate,and protein levels of Hsp90b1,cleaved Caspase-3,and Bax(all P<0.05).The results indicated that there was a targeted regulatory relationship between miR-485-5p and Hsp90b1.Conclusion RRE may inhibit the expression of Hsp90b1 by up-regulating miR-485-5p,thereby inhibiting chondrocyte apoptosis in the rabbit model of KOA.
Animals ; Rabbits ; Apoptosis/drug effects* ; Chondrocytes/pathology* ; Osteoarthritis, Knee/drug therapy* ; MicroRNAs/metabolism* ; Rehmannia/chemistry* ; Disease Models, Animal ; Tumor Necrosis Factor-alpha/blood* ; Plant Extracts/pharmacology* ; Interleukin-6/blood* ; HSP90 Heat-Shock Proteins/metabolism* ; Male ; Drugs, Chinese Herbal/pharmacology*

Objective To explore the effect of Xiongcan Yishen Formula on ferroptosis in testicular tissue of male rats with late-onset hypogonadism(LOH).Methods A total of 48 male Sprague-Dawley rats aged 6 months were randomly divided into model group,low-dose and high-dose Xiongcan Yishen Formula groups and propionate testosterone group,with 12 rats in each group.An additional 6 male Sprague-Dawley rats aged 8 weeks were set as the normal group.Except for the normal group,the rats were intraperitoneally injected with Cyclophosphamide at a dose of 20 mg/(kg·d)for 5 consecutive days to establish the LOH model,while the normal group received an equal volume of physiological saline for 5 days.The normal group and model group were given equal volumes of distilled water by gavage,while the low-dose and high-dose Xiongcan Yishen Formula groups were administered concentrated decoction at doses of 10.4 g and 41.6 g/kg/d respectively,and the propionate testosterone group received intramuscular injections of 5.21 mg/kg/d propionate testosterone,all for 28 consecutive days.ELISA was used to detect serum testosterone levels in rats,HE staining and transmission electron microscopy were used to observe the gross morphology of testicular tissue and the ultrastructure of Leydig cells,and RT-qPCR and Western blotting were used to detect the expression of ferroptosis-related genes and proteins in testicular tissue.Results The LOH model rats exhibited pathological changes such as atrophy of seminiferous tubules,structural disorder,and reduced spermatocytes in the lumen,as well as ultrastructural changes in Leydig cells including altered nuclear morphology,increased mitochondrial density,and reduced cristae.After intervention with Xiongcan Yishen Formula and propionate testosterone,the pathological changes in testis and the ultrastructure of Leydig cells were improved.Compared with the normal group,serum testosterone levels in the model group were significantly decreased(P＜0.05),the expression of ROS,ACSL4 mRNA and protein in testicular tissue was significantly increased,while the expression of FTH1,GPX4,and SLC7A11 mRNA and protein was significantly decreased(P＜0.05).Compared with the model group,ser-um testosterone levels in the low-dose and high-dose Xiongcan Yishen Formula groups and the propionate testosterone group were significantly increased(P＜0.05),and the expression of ROS,ACSL4 mRNA and protein was significantly decreased(P＜0.05);the high-dose Xiongcan Yishen Formula group showed significantly increased expression of FTH1,GPX4,and SLC7A11 mRNA and protein(P＜0.05).Conclusion Ferroptosis in testicular tissue is increased in LOH rats,and Xiongcan Yishen For-mula can elevate serum testosterone levels and improve pathological changes and ultrastructure in testicular tissue of LOH rats,possibly related to the inhibition of ferroptosis in testicular tissue of LOH rats.

OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

OBJECTIVE: To summarize the early clinical results and safety of Stand-alone OLIF application of lumbar lesions, and explored its surgical indications. METHODS: Total of 92 cases of lumbar spine lesions treated with Stand-alone OLIF at two medical centers from October 2014 to December 2018 were retrospectively analyzed, including 30 males and 62 females with an average age of (61.20±12.94) years old ranged from 32 to 83 years old. There were 20 cases of lumbar spinal stenosis, 15 cases of lumbar disc degeneration, 11 cases of lumbar degenerative spondylolisthesis, 6 cases of discogenic low back pain, 7 cases of giant lumbar disc herniation, 13 cases of primary lumbar discitis, 6 cases of adjacent vertebral disease after lumbar internal fixation surgery, and 14 cases of degenerative lumbar scoliosis. Pre-operative dual energy X-ray bone density examination 31 cases' T-values ranged from -1 to -2.4, 8 cases' T-values ranged from -2.5 to -3.5, and the rest had normal bone density. The number of fusion segments: 68 cases of single segment, 9 cases of two segment, 12 cases of three segment , and 3 cases of four segment. Fusion site:L_1,2 1 case, L_2,3 4 cases, L_3,4 10 cases, L_4,5 53 cases, L_2,3-L_3,4 3 cases, L_3,4-L_4,5 6 cases, L_1,2L_2,3L_3,4 1 case, L_1,2L_3,4L_4,5 1 case, L_2,3L_3,4L_4,5 10 cases, L_1,2L_2,3L_3,4L_4,5 3 cases. The clinical results and imaging results of this group of cases were observed, as well as the complications. RESULTS: The surgical time ranged from 40 to 140 minutes with an average of (60.92±27.40) minutes. The intraoperative bleeding volume was 20 to 720 ml with an average of (68.22±141.60) ml. The patients had a follow-up period of 6 to 84 months with an average of (38.50±12.75) months. The height of the intervertebral space recovered from (9.23±1.94) mm in preoperative to (12.68±2.01) mm in postoperative, and (9.11±1.72) mm at the last follow-up, there was a statistically significant difference(F=6.641, P=0.008);there was also a statistically significant difference between the postoperative and preoperative height of the intervertebral space(t=9.27, P<0.000 1);and there was also a statistically significant difference (t=10.06, P<0.000 1) between the last follow-up and postoperative height of the intervertebral space. At the last follow-up, cage subsidence grading was as follows:level 0 in 69 cases (76 segments), levelⅠin 17 cases (43 segments), level Ⅱin 5 cases (14 segments), and level Ⅲ in 1 case (1 segment);according to the number of segments, normal subsidence accounts for 56.72%, abnormal subsidence accounts for 43.28%. Bone mineral desity of normal subsidence groups was -0.50±0.07 whinch was better than that the abnormal subsidence groups -2.10±0.43, and the difference was statistically significant(χ²=2.275, P=0.014). As well as there was a statistically significant difference in the patient's VAS of backache from (6.28±2.11) in preoperative to (1.48±0.59) in last follow-up(t=8.56, P<0.05). The ODI recovered from (36.30±7.52)% before surgery to (10.20±2.50)% at the last follow-up, with a statistically significant difference (t=7.79, P<0.000 1). Complications involved 4 cases of intraoperative vascular injury, 21 cases of endplate injury, and 4 cases of combined vertebral fractures. The incision skin has no necrosis or infection. There were 4 cases of left sympathetic chain injury, 4 cases of transient left hip flexion weakness, 2 cases of left thigh anterolateral numbness with quadriceps femoris weakness, and 1 case of incomplete intestinal obstruction;8 cases were treated with posterior pedicle screw fixation due to fusion cage settlement accompanied by stubborn lower back pain, and 6 cases were treated with fusion cage settlement and lateral displacement. According to the actual number of cases, there were 38 complications, with an incidence rate of 41.3%. CONCLUSION The application of Stand alone OLIF in lumbar spine disease fusion has achieved good early results, with obvious clinical advantages, but also there are high probability of complications. It is recommended to choose carefully. It is necessary to continuously summarize and gradually clarify and complete the surgical indications and specific case selection criteria.
Humans ; Male ; Female ; Middle Aged ; Spinal Fusion/methods* ; Lumbar Vertebrae/injuries* ; Aged ; Adult ; Retrospective Studies ; Aged, 80 and over

To investigate the impact of preoperative serum follicle-stimulating hormone (FSH) levels on the probability of testicular sperm retrieval, we conducted a study of nonobstructive azoospermic (NOA) men with different testicular volumes (TVs) who underwent microdissection testicular sperm extraction (micro-TESE). A total of 177 NOA patients undergoing micro-TESE for the first time from April 2019 to November 2022 in Shenzhen Zhongshan Obstetrics and Gynecology Hospital (formerly Shenzhen Zhongshan Urology Hospital, Shenzhen, China) were retrospectively reviewed. The subjects were divided into four groups based on average TV quartiles. Serum hormone levels in each TV group were compared between positive and negative sperm retrieval subgroups. Overall sperm retrieval rate was 57.6%. FSH levels (median [interquartile range]) were higher in the positive sperm retrieval subgroup compared with the negative outcome subgroup when average TV was <5 ml (first quartile [Q1: TV <3 ml]: 43.32 [17.92] IU l -1 vs 32.95 [18.56] IU l -1 , P = 0.048; second quartile [Q2: 3 ml ≤ TV <5 ml]: 31.31 [15.37] IU l -1 vs 25.59 [18.40] IU l -1 , P = 0.042). Elevated serum FSH levels were associated with successful micro-TESE sperm retrieval in NOA men whose average TVs were <5 ml (adjusted odds ratio [OR]: 1.06 per unit increase; 95% confidence interval [CI]: 1.01-1.11; P = 0.011). In men with TVs ≥5 ml, larger TVs were associated with lower odds of sperm retrieval (adjusted OR: 0.84 per 1 ml increase; 95% CI: 0.71-0.98; P = 0.029). In conclusion, elevated serum FSH levels were associated with positive sperm retrieval in micro-TESE in NOA men with TVs <5 ml. In men with TV ≥5 ml, increases in average TVs were associated with lower odds of sperm retrieval.
Humans ; Male ; Azoospermia/surgery* ; Sperm Retrieval/statistics & numerical data* ; Adult ; Follicle Stimulating Hormone/blood* ; Retrospective Studies ; Testis/pathology* ; Microdissection ; Organ Size

Objective:To investigate the association between serum 25-hydroxy vitamin D [25-(OH)D] levels at 1 and 4 weeks after birth and bronchopulmonary dysplasia (BPD) in preterm infants.Methods:This case-control study included 125 preterm infants (gestational age<32 weeks) admitted to the Department of Neonatology, Hangzhou Women's Hospital between January 2020 and December 2022. All infants received vitamin D supplementation (900 IU/d) starting at 1 week after birth. According to the clinical diagnosis at 28 d after birth, these participants were divided into BPD ( n=57) and non-BPD ( n=68) groups. Two independent sample t-test, Wilcoxon rank-sum test, and Chi-square test were used to compare the general conditions, maternal perinatal conditions, postnatal treatment, complications, and 25-(OH)D levels between the two groups. Pearson bivariate correlation and partial correlation analyses were performed to assess the relationship between 25-(OH)D levels and BPD. Results:The BPD group had lower gestational age [(28.7±1.8) vs. (30.2±0.9) weeks, t=－6.13], birth weight [(1 166.1±238.1) vs. (1 473.8±224.4) g, t=－7.42], and Apgar scores at 1 min [(7.6±2.1) vs. (9.1±1.3) scores, t=－4.58) and 5 min [(8.9±1.2) vs. (9.5±1.1) scores, t=－2.77) compared to the non-BPD group (all P<0.05). The proportion of infants received surfactant therapy [73.7% (42/57) vs. 50.0% (34/68), χ2=7.30], the incidence of maternal preeclampsia [29.8% (17/57) vs. 14.7% (10/68), χ2=4.19], and the incidence of neonatal asphyxia [31.6% (18/57) vs. 16.2% (11/68), χ2=4.13], pneumonia [14.0% (8/57) vs. 1.5% (1/68), χ2=5.57], sepsis [64.9% (37/57) vs. 19.1% (13/68), χ2=27.10], and patent ductus arteriosus [78.9% (45/57) vs. 48.5% (33/68), χ2=12.23] were higher in the BPD group than in the non-BPD group (all P<0.05). The infants with BPD required longer durations of caffeine therapy [(37.2±15.1) vs. (16.8±11.5) d, t=8.58], mechanical ventilation [0.0 (0.0-3.0) vs. 0.0 (0.0-0.0) d, Z=3.52], non-invasive ventilation [23.0 (11.0-31.0) vs. 6.0 (4.0-9.0) d, Z=6.22], total oxygen therapy [46.0 (40.0-58.0) vs. 13.0 (6.0-19.0) d, Z=6.57], and hospitalization [(60.7±15.0) vs. (37.6±7.8) d, t=10.52] than those without BPD (all P<0.05). Serum 25-(OH)D levels were significantly lower in the BPD group than in the non-BPD group at both 1 week [(32.75±7.81) vs. (43.07±9.36) nmol/L, t=－4.60, P<0.001] and 4 weeks [(49.03±11.12) vs. (60.02±14.39) nmol/L, t=－3.90, P<0.001] after birth. Vitamin D deficiency at 1 week after birth was more prevalent in the BPD group than in the non-BPD group [40.0% (10/25) vs. 12.5% (5/40), χ2=6.55, P=0.010]. Serum 25-(OH)D levels at 1 and 4 weeks after birth were negatively correlated with BPD incidence (bivariate analysis: r=－0.50 and－0.40; partial correlation analysis corrected with birth gestational age, birth weight and other general information, the proportion of preeclampsia/cesarean section and other perinatal information of pregnant women, sepsis/mechanical ventilation time and other postnatal diseases and treatment conditions: r=－0.37 and－0.27; both P<0.05). Conclusion:Low serum 25-(OH)D levels at 1 and 4 weeks after birth may be associated with BPD in preterm infants.

Objective To explore the effect of Xiongcan Yishen Formula on ferroptosis in testicular tissue of male rats with late-onset hypogonadism(LOH).Methods A total of 48 male Sprague-Dawley rats aged 6 months were randomly divided into model group,low-dose and high-dose Xiongcan Yishen Formula groups and propionate testosterone group,with 12 rats in each group.An additional 6 male Sprague-Dawley rats aged 8 weeks were set as the normal group.Except for the normal group,the rats were intraperitoneally injected with Cyclophosphamide at a dose of 20 mg/(kg·d)for 5 consecutive days to establish the LOH model,while the normal group received an equal volume of physiological saline for 5 days.The normal group and model group were given equal volumes of distilled water by gavage,while the low-dose and high-dose Xiongcan Yishen Formula groups were administered concentrated decoction at doses of 10.4 g and 41.6 g/kg/d respectively,and the propionate testosterone group received intramuscular injections of 5.21 mg/kg/d propionate testosterone,all for 28 consecutive days.ELISA was used to detect serum testosterone levels in rats,HE staining and transmission electron microscopy were used to observe the gross morphology of testicular tissue and the ultrastructure of Leydig cells,and RT-qPCR and Western blotting were used to detect the expression of ferroptosis-related genes and proteins in testicular tissue.Results The LOH model rats exhibited pathological changes such as atrophy of seminiferous tubules,structural disorder,and reduced spermatocytes in the lumen,as well as ultrastructural changes in Leydig cells including altered nuclear morphology,increased mitochondrial density,and reduced cristae.After intervention with Xiongcan Yishen Formula and propionate testosterone,the pathological changes in testis and the ultrastructure of Leydig cells were improved.Compared with the normal group,serum testosterone levels in the model group were significantly decreased(P＜0.05),the expression of ROS,ACSL4 mRNA and protein in testicular tissue was significantly increased,while the expression of FTH1,GPX4,and SLC7A11 mRNA and protein was significantly decreased(P＜0.05).Compared with the model group,ser-um testosterone levels in the low-dose and high-dose Xiongcan Yishen Formula groups and the propionate testosterone group were significantly increased(P＜0.05),and the expression of ROS,ACSL4 mRNA and protein was significantly decreased(P＜0.05);the high-dose Xiongcan Yishen Formula group showed significantly increased expression of FTH1,GPX4,and SLC7A11 mRNA and protein(P＜0.05).Conclusion Ferroptosis in testicular tissue is increased in LOH rats,and Xiongcan Yishen For-mula can elevate serum testosterone levels and improve pathological changes and ultrastructure in testicular tissue of LOH rats,possibly related to the inhibition of ferroptosis in testicular tissue of LOH rats.

Objective:To investigate the association between serum 25-hydroxy vitamin D [25-(OH)D] levels at 1 and 4 weeks after birth and bronchopulmonary dysplasia (BPD) in preterm infants.Methods:This case-control study included 125 preterm infants (gestational age<32 weeks) admitted to the Department of Neonatology, Hangzhou Women's Hospital between January 2020 and December 2022. All infants received vitamin D supplementation (900 IU/d) starting at 1 week after birth. According to the clinical diagnosis at 28 d after birth, these participants were divided into BPD ( n=57) and non-BPD ( n=68) groups. Two independent sample t-test, Wilcoxon rank-sum test, and Chi-square test were used to compare the general conditions, maternal perinatal conditions, postnatal treatment, complications, and 25-(OH)D levels between the two groups. Pearson bivariate correlation and partial correlation analyses were performed to assess the relationship between 25-(OH)D levels and BPD. Results:The BPD group had lower gestational age [(28.7±1.8) vs. (30.2±0.9) weeks, t=－6.13], birth weight [(1 166.1±238.1) vs. (1 473.8±224.4) g, t=－7.42], and Apgar scores at 1 min [(7.6±2.1) vs. (9.1±1.3) scores, t=－4.58) and 5 min [(8.9±1.2) vs. (9.5±1.1) scores, t=－2.77) compared to the non-BPD group (all P<0.05). The proportion of infants received surfactant therapy [73.7% (42/57) vs. 50.0% (34/68), χ2=7.30], the incidence of maternal preeclampsia [29.8% (17/57) vs. 14.7% (10/68), χ2=4.19], and the incidence of neonatal asphyxia [31.6% (18/57) vs. 16.2% (11/68), χ2=4.13], pneumonia [14.0% (8/57) vs. 1.5% (1/68), χ2=5.57], sepsis [64.9% (37/57) vs. 19.1% (13/68), χ2=27.10], and patent ductus arteriosus [78.9% (45/57) vs. 48.5% (33/68), χ2=12.23] were higher in the BPD group than in the non-BPD group (all P<0.05). The infants with BPD required longer durations of caffeine therapy [(37.2±15.1) vs. (16.8±11.5) d, t=8.58], mechanical ventilation [0.0 (0.0-3.0) vs. 0.0 (0.0-0.0) d, Z=3.52], non-invasive ventilation [23.0 (11.0-31.0) vs. 6.0 (4.0-9.0) d, Z=6.22], total oxygen therapy [46.0 (40.0-58.0) vs. 13.0 (6.0-19.0) d, Z=6.57], and hospitalization [(60.7±15.0) vs. (37.6±7.8) d, t=10.52] than those without BPD (all P<0.05). Serum 25-(OH)D levels were significantly lower in the BPD group than in the non-BPD group at both 1 week [(32.75±7.81) vs. (43.07±9.36) nmol/L, t=－4.60, P<0.001] and 4 weeks [(49.03±11.12) vs. (60.02±14.39) nmol/L, t=－3.90, P<0.001] after birth. Vitamin D deficiency at 1 week after birth was more prevalent in the BPD group than in the non-BPD group [40.0% (10/25) vs. 12.5% (5/40), χ2=6.55, P=0.010]. Serum 25-(OH)D levels at 1 and 4 weeks after birth were negatively correlated with BPD incidence (bivariate analysis: r=－0.50 and－0.40; partial correlation analysis corrected with birth gestational age, birth weight and other general information, the proportion of preeclampsia/cesarean section and other perinatal information of pregnant women, sepsis/mechanical ventilation time and other postnatal diseases and treatment conditions: r=－0.37 and－0.27; both P<0.05). Conclusion:Low serum 25-(OH)D levels at 1 and 4 weeks after birth may be associated with BPD in preterm infants.

Objective To investigate the risk factors for bronchopulmonary dysplasia(BPD)in twin preterm infants with a gestational age of<34 weeks,and to provide a basis for early identification of BPD in twin preterm infants in clinical practice.Methods A retrospective analysis was performed for the twin preterm infants with a gestational age of<34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020.According to their conditions,they were divided into group A(both twins had BPD),group B(only one twin had BPD),and group C(neither twin had BPD).The risk factors for BPD in twin preterm infants were analyzed.Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins.Results A total of 904 pairs of twins with a gestational age of<34 weeks were included in this study.The multivariate logistic regression analysis showed that compared with group C,birth weight discordance of>25%between the twins was an independent risk factor for BPD in one of the twins(OR=3.370,95%CI:1.500-7.568,P<0.05),and high gestational age at birth was a protective factor against BPD(P<0.05).The conditional logistic regression analysis of group B showed that small-for-gestational-age(SGA)birth was an independent risk factor for BPD in individual twins(OR=5.017,95%CI:1.040-24.190,P<0.05).Conclusions The development of BPD in twin preterm infants is associated with gestational age,birth weight discordance between the twins,and SGA birth.