ObjectiveTo elucidate the efficacy connotation of Shudi Qiangjin pills （SQP） against liver and kidney deficiency in steroid-induced osteonecrosis of femoral head （SONFH） from the perspective of the "disease-syndrome-formula" association and to clarify the underlying mechanisms based on in vivo and in vitro experiment validation. MethodsThe chemical components and the corresponding putative targets of SQP were collected from the Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine （TCMIP） v2.0， the Encyclopedia of Traditional Chinese Medicine （ETCM） v2.0， and HERB databases. The SONFH-related genes were identified based on the differential expression profiles of peripheral blood of patients with SONFH compared to the healthy volunteers， and the disease phenotype-related targets were collected from the TCMIP v2.0 database. Then， the interaction network of "SONFH-related genes and candidate targets of SQP" was constructed based on "gene-gene interaction information"， and the major network targets were screened by calculating the topological characteristic values of the network followed by the functional mining according to the Kyoto Encyclopedia of Genes and Genomes （KEGG） database and the SoFDA database. After that， the SONFH rat model was prepared by lipopolysaccharide combined with methylprednisolone injection， and 2.5， 5， 7.5 g·kg^-1 SQP （once per day， equivalent to 1， 2， and 3 times the clinical equivalent dose， respectively） or 7.3×10^-3 g·kg^-1 of alendronate sodium （ALS， once per week， equivalent to the clinical equivalent dose） was given for 8 weeks. The effect characteristics of SQP and ALS in the treatment of SONFH were evaluated by micro-computed tomography scanning， hematoxylin and eosin staining， alkaline phosphatase （ALP） staining， immunohistochemical staining， enzyme-linked immunosorbent assay， and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling（TUNEL）staining， and a comparative efficacy analysis was conducted with ALS. In addition， SONFH cell models were prepared by dexamethasone stimulation of osteoblasts， and the intervention was carried out with the medicated serum of SQP at the aforementioned three doses. Cell counting kit-8， ALP staining， ALP activity assay， alizarin red staining， and flow cytometry were employed to investigate the regulatory effect of SQP on osteoblasts. The expression levels of osteogenesis-related proteins and key factors of the target signaling axis were detected by quantitative real-time polymerase chain reaction and Western blot. ResultsThe network analysis results demonstrated that the candidate targets of SQP primarily exerted their therapeutic effects through key signaling pathways， including phosphoinositide 3-kinase（PI3K）/protein kinase B（Akt）， lipid metabolism and atherosclerosis， prolactin， chemokines， and neurotrophic factors pathways. These pathways were significantly involved in critical biological processes such as muscle and bone metabolism and the regulation of the "neuro-endocrine-immune" network， thereby addressing both modern medical symptoms （e.g.， delayed skeletal maturation and recurrent fractures） and traditional Chinese medicine （TCM） symptoms （e.g.， fatigue， aversion to cold， cold limbs， and pain in the limbs and joints in patients with SONFH characterized by liver and kidney deficiency syndrome. Among these pathways， the PI3K/Akt signaling pathway exhibited the highest degree of enrichment. The in vivo experimental results demonstrated that starting from the 4^th week after modeling， the modeling group exhibited a significant reduction in body weight compared to the control group （P<0.05）. After six weeks of treatment， all dosage groups of SQP showed significantly higher body weights compared to the model group （P<0.01）. Compared with the normal group， the model group exhibited significant decreases in bone mineral density （BMD）， bone volume fraction （BV/TV）， trabecular number （Tb.N）， osteocalcin （OCN）， alkaline phosphatase （ALP） levels in femoral head tissue， and serum bone-specific alkaline phosphatase （BALP） （P<0.01）， along with significant increases in trabecular separation （Tb.Sp）， empty lacunae rate in tissue， and apoptosis rate （P<0.01）. In comparison to the model group， the SQP intervention groups showed significant improvements in BMD， BV/TV and Tb.N （P<0.01）， significant reductions in Tb.Sp， empty lacunae rate and apoptosis rate （P<0.05）， and significant increases in protein levels of OCN and ALP as well as BALP content （P<0.05）. The in vitro experimental results revealed that all dosage groups of SQP medicated serum showed no toxic effects on osteoblast. Compared with the normal group， the model group displayed significant suppression of osteoblast proliferation activity， ALP activity， and calcified nodule formation rate （P<0.01）， significant decreases in mRNA transcription levels of OCN and Runt-related transcription factor 2 （RUNX2） （P<0.01）， significant reductions in protein content of osteopontin （OPN）， typeⅠ collagen （ColⅠ）A1， B-cell lymphoma-2 （Bcl-2）， PI3K， and phosphorylated （p）-Akt （P<0.01）， and a significant increase in apoptosis rate （P<0.01）. Compared with the model group， the SQP medicated serum intervention groups exhibited significant increases in proliferation activity， ALP activity， calcified nodule formation rate， mRNA transcription levels of OCN and RUNX2， and protein content of OPN， ColⅠA1， Bcl-2， PI3K， and p-Akt （P<0.05）， along with a significant decrease in apoptosis rate （P<0.01）. ConclusionSQP can effectively reduce the disease severity of SONFH with liver and kidney deficiency syndrome and improve bone microstructure， with the therapeutic effects exhibiting a dose-dependent manner. The mechanism may be related to its regulation of key processes such as muscle and bone metabolism and the correction of imbalances in the "neuro-endocrine-immune" network， thereby promoting osteoblast differentiation and inhibiting osteoblast apoptosis. The PI3K/Akt signaling axis is likely one of the key pathways through which this formula exerts its effects.

OBJECTIVE To explore and establish a full-cycle management model for drug traceability codes that aligns with national policy requirements and the practical needs of healthcare institutions， thereby enhancing the refinement of drug management and the level of medication safety. METHODS A tripartite strategy integrating “hardware deployment， system transformation， and process re-engineering” was adopted. This involved the introduction of intelligent identification devices （personal digital assistant， high-definition industrial reader）， the modification of the hospital information system interface， and the re-engineering of workflows （drug warehousing， dispensing and distribution， drug withdrawal， uploading to the insurance platform） to achieve comprehensive， informatized collection and association of drug traceability codes throughout all stages. RESULTS A full-cycle management model for drug traceability codes was successfully established， realizing the goals of making drugs “traceable to their source， trackable in their distribution， and accountable in their responsibility”. The patient waiting time for medication dispensing before and after the implementation was [3.08（1.67，5.58）] min and [3.28（1.77，5.98）] min， respectively. Among them， the patient waiting time under the pre-preparation mode was [3.60（2.13，6.35）] min and [3.50（2.03，6.30）] min， respectively； the patient waiting time under the real-time mode was [2.05（0.83，4.03）] min and [2.78（1.18，5.38）] min， respectively； the number of dispensing errors was 3， 0， respectively； the staffing of relevant positions had not been increased. CONCLUSIONS The drug traceability code management model constructed from a full-cycle perspective effectively meets national policy requirements. It provides data support for refined hospital management and offers solid technical and procedural safeguards for ensuring patient medication safety and strengthening medical insurance fund supervision， demonstrating practical value.

OBJECTIVE: To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention. METHODS: Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010). RESULTS: In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born. CONCLUSION This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans ; Female ; Male ; Pedigree ; Exostoses, Multiple Hereditary/diagnosis* ; N-Acetylglucosaminyltransferases/genetics* ; Adult ; Exostosin 1 ; Asian People/genetics* ; Genetic Testing ; Exostosin 2 ; Mutation ; China ; Prenatal Diagnosis ; Pregnancy ; Genetic Counseling ; Preimplantation Diagnosis ; Exome Sequencing ; East Asian People

ObjectiveThe exacerbating trend of global population aging poses profound socioeconomic and public health challenges, making the comprehensive elucidation of biological aging mechanisms and the discovery of effective anti-aging interventions an urgent priority in the life sciences. Based on our previous serum metabolomics findings that dimethylglycine, an intermediate metabolite of amino acid metabolism naturally present in the human body, was significantly enriched in the serum of longevity families, this study aimed to systematically investigate the anti-aging effects of dimethylglycine both in living organisms and in controlled laboratory environments, and to preliminarily elucidate its underlying molecular mechanisms. While existing literature indicates that dimethylglycine possesses antioxidant and immunomodulatory properties, its direct anti-aging efficacy and the specific molecular pathways through which it operates remain largely unexplored. MethodsTo comprehensively evaluate the anti-aging properties of dimethylglycine, we utilized replicative senescent human embryonic lung fibroblasts, specifically the WI-38 cell line, as an experimental model in a controlled laboratory environment. Cell viability and safety were thoroughly assessed using Cell Counting Kit-8 and lactate dehydrogenase release assays across various concentrations of dimethylglycine. The impact of dimethylglycine on cellular senescence phenotypes, oxidative stress, and proliferative capacity was evaluated via senescence-associated beta-galactosidase staining, reactive oxygen species fluorescence detection, and 5-ethynyl-2'-deoxyuridine incorporation assays. Furthermore, the molecular alterations of senescence-associated secretory phenotype factors and core senescence signaling pathways were quantified using quantitative reverse transcription polymerase chain reaction for the messenger RNA levels of interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1, and enzyme-linked immunosorbent assay for the measurement of p16 and p21 protein expression levels. For the living organism model, the wild-type nematode Caenorhabditis elegans was used to evaluate systemic physiological effects. We conducted a comprehensive lifespan analysis at 20°C, heat stress resistance survival assays at 35℃, senescence-associated beta-galactosidase staining, lipofuscin accumulation tracking, intracellular reactive oxygen species measurement, and Oil Red O staining to ascertain systemic lipid accumulation. Additionally, network pharmacology bioinformatics tools, including PharmMapper and STRING databases, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were utilized to predict target pathways, alongside highly detailed molecular docking simulations utilizing SwissDock and Protein-Ligand Interaction Profiler to examine interactions with the cytochrome P450 family 2 subfamily C member 9 protein. ResultsThe experimental outcomes robustly demonstrate the potent anti-aging capabilities of dimethylglycine. At the cellular level, toxicity analyses firmly confirmed that dimethylglycine is highly safe; continuous treatment with 50 mol/L and 70 mol/L of dimethylglycine for 5 d did not induce any cellular membrane damage or cytotoxicity, but rather actively promoted cellular proliferation. Utilizing the optimal standardized concentration of 50 mol/L, dimethylglycine treatment significantly ameliorated senescent phenotypic markers in human embryonic lung fibroblasts, which was evidenced by a drastic and highly significant reduction in the senescence-associated beta-galactosidase positive cell percentage (P<0.000 1) and intracellular reactive oxygen species levels (P<0.000 1), alongside a marked increase in the 5-ethynyl-2'-deoxyuridine-positive proliferation rate (P=0.003 5). On a molecular expression scale, dimethylglycine significantly downregulated the messenger RNA expression of multiple core senescence-associated secretory phenotype inflammatory factors, including interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1. Concurrently, it effectively suppressed the protein expression of critical cell cycle arrest markers, diminishing p16 protein levels by 57.3% (P=0.000 4) and p21 protein levels by 27.2% (P=0.000 7). In the nematode Caenorhabditis elegans animal model, dimethylglycine significantly extended the mean lifespan from 20.402 d to an impressive 23.066 d (P<0.000 1) and notably enhanced overall survival rates under severe heat stress environmental conditions (P=0.017). Furthermore, systemic dimethylglycine intervention significantly mitigated age-related physiological decline by decreasing bodily lipofuscin accumulation (P<0.000 1), significantly reducing senescence-associated beta-galactosidase activity, lowering systemic reactive oxygen species fluorescence (P=0.008), and effectively alleviating overall fat accumulation (P<0.000 1). Mechanistically, extensive network pharmacology and Kyoto Encyclopedia of Genes and Genomes analyses strongly revealed that the potential targets of dimethylglycine are significantly enriched in fundamental drug metabolism and oxidative stress response pathways. Precision molecular docking simulations conclusively demonstrated that dimethylglycine forms highly stable structural interactions with the cytochrome P450 family 2 subfamily C member 9 protein, specifically highlighting the definitive formation of 5 stable hydrogen bonds involving serine 365, leucine 366, and serine 429 residues, as well as two critical salt bridge formations with arginine 97 and histidine 368 residues. It is additionally predicted to interact favorably with glutathione S-transferase family proteins. ConclusionDimethylglycine exhibits a profoundly significant and multifaceted anti-aging activity at both the cellular and entire living animal levels. By powerfully alleviating oxidative stress, heavily suppressing the core p16 and p21-dependent cellular senescence signaling pathways, and substantially mitigating the detrimental senescence-associated secretory phenotype, dimethylglycine effectively delays fundamental cellular senescence processes and drastically extends whole-organism lifespan. The biological mechanisms driving these robust protective effects are highly likely closely associated with its direct stable interactions with crucial metabolic and detoxifying enzyme systems, such as cytochrome P450 family 2 subfamily C member 9 and glutathione S-transferase family proteins, thereby systemically improving metabolic dysregulation and restoring critical redox homeostasis. This comprehensive study provides highly solid experimental evidence supporting dimethylglycine as a highly potent and safe potential anti-aging intervention agent, while simultaneously offering a clear molecular mechanistic explanation for the previously documented high abundance of dimethylglycine observed within exceptionally long-lived human populations.

Objective: To explore the management of blood donors tested reactive to HCV in blood screening based on confirmation of HCV infection. Methods: Multiple HCV antibody assays, repeating HCV RNA testing, follow-up of blood donors and retesting of archive samples were performed to confirm HCV infection, identify infection status, and exclude false positives in blood donors reactive to HCV in blood screening. Results: From 2011 to 2024, the unqualified rate of HCV detection in blood screening was 2.45‰(2 751/1 122 026). Among these, anti-HCV+-&NAT-accounted for 1.85‰, followed by anti-HCV++ at 0.60‰. The proportion of anti-HCV+-&NAT-and HCV RNA yields was extremely low (0.007‰). The positive rate of anti-HCV+-&NAT-samples tested by electrochemiluminescence method (ELCIA) was approximately 7.5%, differing among reagents (P<0.05). The follow-up of anti-HCV+-&NAT-donors showed that 96.2% (202/210) were false positives, but 51.4% of donors remained anti-HCV+-&NAT-during follow-up. Among them, 8 donors (3.8%) could not be ruled out from HCV infection due to positive retesting by ELCIA. Of the anti-HCV+-&NAT-donors who were reactive at the first follow-up, 86.8% remained anti-HCV+-&NAT-at the second follow-up. The sampling confirmation data showed that all of 260 anti-HCV++ donors were confirmed as anti-HCV positive, and the proportion of false positives or missed detections by NAT was very low. Two occult HBV infections (OBIs) and one HBsAg carrier were identified among the 3 anti-HCV +-&NAT+ donors, and no HCV infection was confirmed in 5 anti-HCV--&HCV RNA + donors. Conclusion: The prevalence of HCV among blood donors in Dalian was about 0.06%, with extremely low proportion of window-period infection and slightly higher proportion of resolved infections than that of current infections. The majority of anti-HCV+-&NAT-were false positive. Blood donors confirmed as false positive should be qualified in blood screening 3 months later before next donation. In order to reduce the false positive results, it was advisable to avoid the same type of supplementary reagents as the initial reagents when performing confirmation.

OBJECTIVE To investigate the effect of plasma trough concentration of venetoclax and its influencing factors in patients with acute myeloid leukemia （AML）. METHODS After 5 days of venetoclax administration， venous blood samples were collected from AML patients before the next dose. Plasma trough concentrations of venetoclax were determined using high-performance liquid chromatography-tandem mass spectrometry. Spearman correlation was used to assess the correlations between venetoclax plasma trough concentration and various parameters （including patients’ general information， venetoclax-related indicators， liver function indicators， kidney function indicators， and blood routine indicators）. Multiple linear regression analysis was performed to identify independent factors influencing plasma trough concentration of venetoclax. Using efficacy as dependent variable [complete remission （CR）+partial remission （PR） vs. no remission （NR）]， univariate and multivariate binary Logistic regression analyses were conducted to identify factors affecting efficacy. The receiver operating characteristic （ROC） curve was used to evaluate the predictive value of venetoclax plasma trough concentration for clinical efficacy （assessed as CR）. RESULTS A total of 172 venetoclax plasma trough concentration measurements from 101 patients were included in this study. The median plasma trough concentration of venetoclax was 2.38 （1.18， 3.85） μg/mL； the median sampling time for plasma trough concentration of venetoclax was 10 （7， 15） d； the duration of venetoclax use was （34±12） d. Multiple linear regression analysis showed that alkaline phosphatase （ B ＝14.65， 95%CI： 5.35-23.95， P ＝0.002）， total bilirubin （ B ＝－101.71， 95%CI： －197.16 to －6.25， P ＝0.037）， and white blood cell count （ B ＝－106.84， 95%CI： －187.61 to －26.07， P ＝0.010） were independent factors influencing plasma trough concentration of venetoclax. Due to patient attrition during treatment， 114 venetoclax plasma trough concentration measurements from 69 patients were included for efficacy evaluation. The results showed that 46 patients （66.7%） achieved CR， 11 patients （15.9%） achieved PR， and 12 patients （17.4%） were NR. Multivariate binary Logistic regression analysis showed that age， hemoglobin， venetoclax plasma trough concentration， hematocrit， and mean corpuscular hemoglobin were independent factors affecting patient efficacy （ P ＜0.05）. ROC curve analysis showed that the cut-off value of plasma trough concentration of venetoclax for predicting patient efficacy （assessed as CR） was 1.68 μg/mL （AUC＝0.66， 95%CI： 0.54-0.78， P ＝0.014）. CONCLUSIONS There is considerable inter-individual variability in plasma trough concentration of venetoclax among AML patients. Plasma trough concentration of venetoclax is significantly correlated with alkaline phosphatase， total bilirubin， and white blood cell count. Plasma trough concentration of venetoclax is an independent factor affecting patient’s efficacy， and when the cut-off value for predicting CR is above 1.68 μg/mL， better effects may be achieved.

Objective To explore the number of peripheral blood regulatory T cells (Treg) in patients with chronic kidney disease (CKD) and its correlation with vascular calcification. Methods This was a single-center, cross-sectional, and observational study. Non-dialysis patients with CKD treated at Zhongshan Hospital, Fudan University from March 2021 to March 2022 were enrolled. Abdominal aortic calcification (AAC) was assessed using lateral abdominal X-ray. Number of Treg and cytokine levels were measured by flow cytometry. Logistic regression analysis was performed to evaluate the related factors for AAC in CKD patients. Results A total of 83 patients were included, aged 17–86 years, with 57 males (68.7%). The distribution of CKD stages was as follows: stage G1 in 7 patients (8.4%), stage G2 in 17 patients (20.5%), stage G3 in 21 patients (25.3%), stage G4 in 19 patients (22.9%), and stage G5 in 19 patients (22.9%). No AAC was observed in patients with stages G1 and G2, while the prevalence of AAC in patients with stages G3, G4, and G5 was 23.8%, 21.1%, and 26.3%, respectively. Compared with stage G1 patients, those with stages G3–5 showed decreased number of peripheral blood Treg and elevated levels of interleukin (IL)-6 and IL-17F (P＜0.05). The area under the receiver operating characteristic curve for number of peripheral blood Treg in predicting AAC in CKD patients was 0.766 (95%CI 0.652–0.879, P＝0.002). Logistic regression analysis showed that decreased number of Treg was related factor for AAC in CKD patients (OR＝0.957, 95%CI 0.922–0.992, P＝0.018). Conclusion As CKD progresses, number of peripheral blood Treg significantly decreases, which is correlated with AAC in CKD patients.

Objective: To explore the association between negative life events and smartphone addiction among middle school students, so as to provide theoretical support and practical guidance for prevention and intervention of smartphone addiction among middle school students. Methods: Using cluster sampling, 8 890 students were selected to survey from 27 junior high schools and 3 senior high schools in a district of Shenzhen in 2022 (baseline) and 2023 (followup). Data were collected through selfresigned questionnaires on basic information, the Smartphone Addiction Scale-Short Version, and the Adolescent Selfrating Life Events Checklist. Mixedeffects models were employed to analyze the association. Results: Compared to 2022, the punishment scores of middle school students in 2023 [1.00 (0.00, 6.00) and 1.00 (0.00, 6.00)] decreased (Z=4.27), while the scores of interpersonal stress, learning stress and adaptation [4.00(0.00, 8.00), 4.00(0.00, 8.00); 4.00(1.00, 8.00), 5.00(2.00, 9.00); 2.00 (0.00, 6.00), 3.00 (0.00, 7.00)] increased (Z=-3.04, -8.36, -6.80) (P<0.01). Mixedeffects models revealed a positive doseresponse relationship between negative life events and smartphone addiction (OR=1.08-1.17, P<0.01). Stepwise regression showed independent positive effects of interpersonal stress (OR=1.05), academic stress (OR=1.03), and adaptation stress (OR=1.11) on smartphone addiction (P<0.01). Subgroup analysis of nonaddicted students in 2022 confirmed persistent associations for academic stress (OR=1.03) and adaptation (OR=1.07) (P<0.01). Conclusion Negative life events exhibit a positive doseresponse relationship with smartphone addiction, particularly interpersonal stress, academic stress, and adaptationrelated events.

Objective: To explore the longitudinal association between only-child status and smartphone addiction among middle school students, so as to provide a basis for establishing family intervention measures for smartphone addiction in middle school students. Methods: In October 2022 and October 2023, a preliminary survey and follow-up were conducted among 8 759 middle and high school students from 30 schools in a district of Shenzhen. A self-designed questionnaire was used to determine whether the students were the only-child, and the Chinese Version of the Smartphone Addiction Scale-Short Version (C-SAS-SV) was utilized to assess the students smartphone addiction status. A multilevel mixed-effects model and subgroup analysis were applied to examine the association between only-child status and smartphone addiction among middle school students. Results: During 2022 to 2023, the prevalence of smartphone addiction in the cohort of middle school students increased from 24.1% to 25.2%. Compared with only-child, non-only child were more likely to be addicted to smartphones (adjusted model: OR =1.2, 95% CI =1.1-1.4) and also scored higher on smartphone addiction (adjusted model: β =0.9, 95% CI =0.2-1.5)( P <0.05). Subgroup analysis further revealed that compared to baseline, non-only child demonstrated an increased prevalence of smartphone addiction (adjusted model: OR = 1.2 , 95% CI =1.0-1.5) and higher addiction scores (adjusted model: β =0.8, 95% CI =0.2-1.5) after one year( P <0.05). Conclusions Non-only child face higher risk of smartphone addiction. Under the current population policy, it is crucial to address smartphone addiction among middle school students who is not only child.

Objective: To explore the potential causal association between adolescent compulsive behaviour and smartphone addiction based on longitudinal data, so as to provide reference for the establishment of adolescent smartphone addiction interventions. Methods: A preliminary survey and follow-up were conducted on 8 907 middle and high school students in a district of Shenzhen in 2022 and 2023, respectively. Compulsive behaviours were measured by using the Mental Health Inventory for Middle School Students-60 Items (MMHI-60), smartphone addiction was assessed by using the Smartphone Addiction Scale-Short Version ( SAS- SV), and the associations between compulsive behaviours and smartphone addiction were analysed by using multilevel mixed-effects models and subgroup analyses. Results: Smartphone addiction detection rates among middle school students were significantly associated with genders, father s education level, mother s education level, study load subgroups, and whether or not they were single-parent families, and there were statistical differences ( χ 2=17.21-175.34, P <0.05). Students with compulsive behaviours were 2.98 times more likely to develop smartphone addiction than those without compulsive behaviours ( OR=2.98, 95%CI=2.77-3.22, P <0.05). Subgroup analysis of middle school students without smartphone addiction in the first year found that compulsive behaviours significantly predicted smartphone addiction ( OR= 1.76 , 95%CI=1.54-2.01, P <0.05). Conclusion There is a potential causal association between obsessive-compulsive behaviours and smartphone addiction in middle school students, and obsessive-compulsive behaviours in middle school students could significantly predicted the occurrence of smartphone addiction.