Microbiota metabolites in bone: Shaping health and Confronting disease.

The intricate interplay between the gut microbiota and bone health has become increasingly recognized as a fundamental determinant of skeletal well-being. Microbiota-derived metabolites play a crucial role in dynamic interaction, specifically in bone homeostasis. In this sense, short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate, indirectly promote bone formation by regulating insulin-like growth factor-1 (IGF-1). Trimethylamine N-oxide (TMAO) has been found to increase the expression of osteoblast genes, such as Runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein-2 (BMP2), thus enhancing osteogenic differentiation and bone quality through BMP/SMADs and Wnt signaling pathways. Remarkably, in the context of bone infections, the role of microbiota metabolites in immune modulation and host defense mechanisms potentially affects susceptibility to infections such as osteomyelitis. Furthermore, ongoing research elucidates the precise mechanisms through which microbiota-derived metabolites influence bone cells, such as osteoblasts and osteoclasts. Understanding the multifaceted influence of microbiota metabolites on bone, from regulating homeostasis to modulating susceptibility to infections, has the potential to revolutionize our approach to bone health and disease management. This review offers a comprehensive exploration of this evolving field, providing a holistic perspective on the impact of microbiota metabolites on bone health and diseases.

Application of Digital Orthopedic Technology in Orthopedic Trauma.

In order to solve the limitation of auxiliary treatment means in the process of orthopedic trauma surgery, and further improve the effective integration of orthopedic trauma clinical surgery and computer technology, a new orthopedic trauma auxiliary treatment means based on digital orthopedic technology was proposed with the aid of virtual digital technology. The method builds a 3D model of fracture fragments through 3D orthopedic modeling and obtains a high-quality 3D model through processing. Later clinical tests verify the feasibility of this auxiliary treatment method. The test results show that the precision of the 3D reconstruction model based on custom option fitting is higher than that based on optimal option fitting, and the precision difference is within 0.2%. This result also indicates that the 3D model obtained by 3D reconstruction has higher accuracy. The results show that three-dimensional finite element modeling technology can accurately simulate the stress of the spine of orthopedic patients and can reduce the incidence of complications through preoperative diagnosis, curative effect prediction, and trauma surgery, which has a good aid for postoperative recovery.

Nuciferine attenuates acute ischemic stroke in a rat model: a metabolomic approach for the mechanistic study.

Lotus leaves have the dual identity of medicine and food homology as included in the Chinese Pharmacopoeia. Nuciferine is the major bioactive component which is highly abundant in the leaves of Nelumbo nucifera Gaertn. Nuciferine has been shown to potentially improve energy metabolism and protect neurons in cerebral ischemia. However, the mechanisms underlying the protective effects of nuciferine on acute ischemic stroke (AIS) are still unclear. Metabolomics was used for uncovering the underlying therapeutic mechanism of nuciferine in AIS with the help of 1H NMR. The rat model of AIS was generated by the occlusion of the middle cerebral artery (MCAO). After treatment with nuciferine, several indexes of oxidative stress and inflammation, such as total antioxidant capacity (T-AOC), total glutathione/oxidized glutathione (GSH/GSSG), malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were significantly improved, and some metabolic biomarkers (histidine, glycine, glycerol, serine, tyrosine, lysine, choline, etc.) were significantly regulated. Bioinformatic analysis demonstrated that these biomarkers and the derived genes (myeloperoxidase, catalase, etc.), fatty acid and amino acid metabolisms and 9 key metabolic pathways were involved in the nuciferine activity, which indicated the potential therapeutic mechanisms of nuciferine in AIS.

Establishment and characterization of a spinal cord tissue cell line from mandarin fish, Siniperca chuatsi and its susceptibility to several viruses.

In this study, we established and characterized a continuous cell line from the spinal cord tissue of mandarin fish, Siniperca chuatsi and assessed its susceptibility to infectious spleen and kidney necrosis virus (ISKNV), Siniperca chuatsi ranavirus (SCRaV) and Siniperca chuatsi rhabdovirus (SCRV). The cell line, named SCC, has been successively cultured up to 40 passages. The optimal growing conditions of SCC cells were in Leibovitz's L-15 medium supplemented with 20% foetal bovine serum (FBS) at 28°C. Karyotype analysis demonstrated 48 normal diploid chromosomes in the cells. The identity of S. chuatsi origin of SCC cells was confirmed by partial sequencing of the 16S rRNA and cytochrome oxidase I (COI) genes. Infection susceptibility assessment showed that ISKNV, SCRIV and SCRV and can be stably produced and transmitted in SCC cells, and the replication efficiency of ISKNV, SCRaV and SCRV ranged from 107.4 to 109.6 TCID50 /ml. In addition, transmission electron microscopy analysis of ISKNV, SCRAV and SCRV infected SCC cells showed numerous viral particles. In conclusion, the newly established SCC cells provide an important tool for isolation and production of viruses, as well as for molecular and cell biology studies.

Silica nanoparticle-modified microcomb electrode for voltammetry detection of osteopontin with high sensitivity.

Osteosarcoma is a commonly occurring bone malignancy, and it is the second most common cause of cancer deaths in adolescents and children. A sensitive silica nanoparticle (Si-NP) modified current-volt sensor was introduced to identify the osteopontin antigen, a well-known biomarker for osteosarcoma. Si-NP was extracted from the rice husk ash and utilized for the surface functionalization on the interdigitated microelectrode sensing surface. Extracted Si-NP has a spherical shape with uniform distribution, and it is confirmed by field emission scanning electron microscopy and field-emission transmission electron microscopy. Si-NP was layered on the electrode surface through a (3-aminopropyl)triethoxysilane amine linker, and the antibody was immobilized on Si-NP through a glutaraldehyde linker. Osteopontin was effectively detected on the antibody-attached surface, and the determination limit was 0.6 ng/mL. The regression was determined as y = 0.9366x - 1.1113 and the R2 value was 0.9331 and the detection limit of osteopontin was 0.6 ng/mL in the range between 0.3 and 5 ng/mL. In addition, control performance with nonimmune antibodies and albumin did not change the current volt, showing the specific osteopontin identification. This research work brings out the easy and cost-effective method to diagnose osteosarcoma and its etiology.

Relationship Between Femur and Femoral Arteries for Identifying Risk Factors for Vascular Injury.

BACKGROUND This study aimed to identify risk factors for vascular injury in proximal femoral fracture through identifying frequency and distances between femur and femoral arteries with computed tomography angiography and 3-dimensional reconstruction. MATERIAL AND METHODS In a series of 400 participants, based on measurement results regarding the distribution of femoral arteries in the medial femur, the femoral portion covering that part was divided into levels A-E. The center region, margin region, and risky area in the medial femur were defined. The frequency of femoral arteries and interested shortest distance between the outer femur and superficial, deep, and perforating femoral arteries (SFAs, DFAs, and PFAs) in the center region, margin region, and risky area at each level were recorded. RESULTS There were 173 males and 227 females (average age: 63.61±19.18 years) in this study. The starting point and end point for femoral arteries in the medial femur were from 22.55±4.23% to 54.56±8.39% of the whole femur. The femoral arteries in the medial femur mainly were distributed at levels B (88.2%), C (65.9%), and D (40.6%). The femoral arteries in center regions in the risky area, most of which were DFAs and PFAs, were mainly concentrated at levels B (26.93%) and C (11.81%). CONCLUSIONS The mid-shaft level was the most risky level, and the DFAs and PFAs were easier to injure than the SFAs when performing internal fixation of proximal femoral fracture. We recommended that great attention be paid to drill and screw insertion around the mid-shaft level for prevention of iatrogenic vascular injury.

Imaging Evaluation of the Safe Region for Distal Locking Screw of Proximal Femoral Nail Anti-Rotation in Patients with Proximal Femoral Fracture.

BACKGROUND Proximal femoral nail anti-rotation (PFNA) is a standard femoral intertrochanteric fracture operation. Iatrogenic vascular injury, although uncommon, is a reported complication of PFNA surgery as well as a complication of hip fracture surgery. This study aimed to compare the safety and best use of the distal locking screw in 170 mm PFNA and 240 mm PFNA devices, and to determine the safe region for placement of the distal locking screw in PFNA surgery. MATERIAL AND METHODS A retrospective analysis of 100 patients with 170 mm PFNA and 80 patients with 240 mm PFNA were retrospectively analyzed. Two levels of PFNA distal locking screws were equally divided into three planes: I, II, III, for 170 mm PFNA devices and i, ii, iii for the 240 mm PRNA devices. The medial half of the femur was equally divided into eight regions: A to H. The distance between the outer femur and the superficial, the deep and the perforating femoral arteries (SFAs, DFAs, and PFAs), and angles between the reference line and the connection line between the femur center to each artery were measured. RESULTS SFAs and DFAs but not PFAs were found in risky or hazardous regions, and DFAs were obviously closer to the femur than SFAs and PFAs at the same level. In the region within 10 mm of the femur, no SFAs were found. The short nails (170 mm PFNA-II devices) were the closest to the DFAs region, indicating that the 170 mm PFNA-II nails are most likely to cause special vessel injury. The short nails were relatively more distant from the SFAs, which were located posteriorly to the long nails (240 mm PFNA-II). CONCLUSIONS The distal locking screw of the 170 mm PFNA device was more prone to damage the femoral deep artery when the two types of PFNA devices are compared in patients who were candidates for both types of devices.

d-Dimer as a Screening Marker for Venous Thromboembolism After Surgery Among Patients Younger Than 50 With Lower Limb Fractures.

OBJECTIVE: For the present study, the authors hypothesized that the d-dimer levels would be systematically raised in a postoperative population of patients younger than 50 with lower limb fractures and to define a feasible cutoff value for identification of venous thromboembolism (VTE). METHODS: Doppler ultrasonography of lower limbs was performed pre- and postoperatively to evaluate for deep vein thrombosis in 150 patients who underwent open reduction and internal fixation (ORIF). Plasma d-dimer levels were assessed 2 days before surgery and on the 3rd, 7th, and 10th days after surgery. Statistical analysis was carried out to define a feasible threshold for the d-dimer levels. RESULTS: Plasma d-dimer levels were found to be systematically raised postoperatively, and they differed between patients with and without VTE significantly. On the third day after surgery, d-dimer levels of more than 3 mg/L indicated VTE with a sensitivity of 88.37% and a specificity of 96.96%, allowing for the definition of a feasible cutoff value. Duration of surgery, duration of tourniquet, ventilation time, and time of postoperative immobility of lower limbs were identified as highly significant risk factors for the development of VTE. CONCLUSION: Using a threshold of 3 mg/L, the d-dimer levels will screen out VTE with a high degree of sensitivity and specificity in younger patients who have undergone ORIF for lower limb fractures.

The Efficacy Comparison of Tranexamic Acid for Reducing Blood Loss in Total Knee Arthroplasty at Different Dosage Time.

BACKGROUND: This study aimed to compare the efficacy of intravenous administration of tranexamic acid for reducing blood loss in total knee arthroplasty at different dosage time. METHODS: From February 2013 to December 2015, a total of 180 patients (47 in male and 133 in female) who were planned to undergo total knee arthroplasty in our trauma center were recorded. Based on dosage time of tranexamic acid administration, participants were divided into groups A, B, C, and D randomly. In groups A, B, and C, tranexamic acid (30 mg/kg) was infused intravenously 15 minutes before or after tourniquet inflation or on tourniquet deflation respectively, tranexamic acid was not applied in group D. Total blood loss (intraoperative and postoperative blood loss), blood transfusion rate and volume, hemoglobin level, and incidence of deep vein thrombosis were recorded and analyzed. RESULTS: Compared with groups B, C, and D, there were significant reduction of blood loss, hemoglobin, and blood transfusion rate in group A (P < .05). Besides, there was no significant difference between groups B and C with superior efficacy than group D. CONCLUSION: Intravenous administration of tranexamic acid before tourniquet inflation was superior in terms of hemoglobin reduction, reducing blood loss and blood transfusion rate.

The outcome comparison of the suprapatellar approach and infrapatellar approach for tibia intramedullary nailing.

OBJECTIVES: This paper aimed to compare the outcome of suprapatellar and infrapatellar approaches for the tibia intramedullary nailing. METHODS: From February 2010 to August 2013, a total of 162 skeletally mature participants with tibia shaft fractures were identified and divided into suprapatellar approach group (SPAG) and infrapatellar approach group (IPAG) randomly. Fluoroscopy time, length of hospital stay, operative time, blood loss and complications were recorded. Visual analog score (VAS), Lysholm knee score and range of motion (ROM) were reviewed at one, three, six, 12 and 24 months post-operatively. All patients were required to complete short form 36 questionnaire (SF-36) at six, 12 and 24 months postoperatively. RESULTS: The follow-ups lasted two years at least. No significant differences were in major complication rate, operation time, blood loss, the ROM of injured extremity and length of hospital stay between SPAG and IPAG. Nevertheless, the fluoroscopy time was significantly lower in SPAG. VAS pain scores were lower in SPAG at six, 12 and 24 months post-operatively. A higher Lysholm knee score was observed in SPAG at six and 24 months post-operatively. Besides, a better overall physical components score was observed in SPAG except at six months post-operatively. CONCLUSIONS: The suprapatellar approach was superior to infrapatrellar approach for the treatment of tibia shaft fracture. Therefore, we recommend the suprapatellar approach as a preferable approach in tibia intramedullary nailing.

Intramedullary versus extramedullary fixation in the management of subtrochanteric femur fractures: a meta-analysis.

BACKGROUND: Intramedullary and extramedullary fixation methods are used in the management of subtrochanteric femur fractures. However, whether intramedullary or extramedullary fixation is the primary treatment for subtrochanteric femur fractures in adults remains debatable. LEVEL OF EVIDENCE: Meta-analyses of prospective studies, level I. MATERIALS AND METHODS: The Cochrane library, Embase, Google Scholar, and PubMed databases were searched separately for all relevant studies published before January 1, 2015. No language restriction was applied. Prospective randomized controlled trials that compared intramedullary or extramedullary internal fixation to repair subtrochanteric femur fractures in adults were included. We determined intraoperative data, postoperative complications, fracture fixation complications, wound infection, hospital stay days, and final outcome measures to assess the relative effects of different internal fixation methods for the treatment of subtrochanteric femur fractures in adults. RESULTS: Six studies were included in our meta-analysis. The relative risks (RRs) of revision rate was 83% lower (RR, 0.17, 95% confidence interval [CI], 0.05 to 0.60; P=0.006), fixation failure rate was 64% lower (RR, 0.36, 95% CI, 0.12 to 1.08; P=0.07), non-union rate was 77% lower (RR, 0.23, 95% CI, 0.07 to 0.81; P=0.02) in the intramedullary group compared with the extramedullary group. No significant differences were found between the intramedullary group and extramedullary group for intraoperative data, postoperative complications, wound infection, hospital stay days or final outcome measures. CONCLUSION: In conclusion, our meta-analysis suggests that there was no significant difference in intraoperative data, postoperative complications, wound infection, hospital stay days or final outcome measures between intramedullary and extramedullary internal fixation. However, a significant decrease occurred in the rate of fracture fixation complications for patients treated with intramedullary internal fixation, especially in elderly patients. Some differences were not significant, but the treatment of elderly subtrochanteric femur fractures using intramedullary internal fixation is recommended.

Comparison of primary radial head replacement and ORIF (open reduction and internal fixation) in Mason type III fractures: a retrospective evaluation in 72 elderly patients.

BACKGROUND: The aim of this study was to compare radial head prosthesis replacement with open reduction and internal fixation (ORIF) in the surgical treatment of Mason type III radial head fractures in 72 elderly patients. MATERIAL/METHODS: Seventy-two elderly patients (mean age, 67.1±1.25 years, range, 62-81 years) with Mason type III radial head fractures were treated from January 2001 to June 2012. Of these, 37 cases received radial prosthesis and 35 cases were treated with ORIF. All patients were followed up for 10 to 15.6 months. RESULTS: Based on the elbow functional evaluation criteria score by Broberg and Morrey, 29 cases achieved excellent results, 7 were good, and 1 was fair in the replacement group. In the ORIF group, excellent results were seen in 24 cases, good in 9, and fair in 2. The rates of good or excellent results were 78.4% and 68.6% for prosthesis replacement patients and ORIF patients, respectively (P<0.05). The Visual Analogue Scores (VAS) for replacement and ORIF groups were 2.25 and 1.67, respectively (P<0.05). CONCLUSIONS: The radial head prosthesis replacement method is a relatively better surgical approach than ORIF in the treatment of elderly patients with Mason type III radial head fractures.

Genetic G2548A polymorphism of leptin gene and risk of cancer: a meta-analysis of 6860 cases and 7956 controls.

PURPOSE: The results from the published studies on the association between LEP (leptin) genetic polymorphism and cancer risk are conflicting. The common G2548A genetic polymorphism has been reported to be functional and may contribute to genetic susceptibility to cancers. However, the association between LEP G2548A genetic polymorphism and cancer risk remains inconclusive. METHODS: To better understand the role of LEP G2548A genetic polymorphism in global cancer, we conducted this comprehensive meta-analysis encompassing 6860 cases and 7956 controls. RESULTS: Overall, the LEP G2548A genetic polymorphism was associated with higher cancer risk in three genetic models (AA vs GG, AA vs AG/GG, A vs G). In the stratified analysis, there was significant association of LEP G2548A variant with non-Hodgkin's lymphoma (NHL) under homozygous co-dominant model (OR=1.27, 95% CI 1.01-1.60) and additive genetic model (OR=1.14, 95% CI 1.01-1.28). Moreover, a significantly increased cancer risk was found in three genetic models (AA vs GG, AA vs AG/GG, A vs G) among Caucasian population. For Asians, no significant associations were observed in any genetic model tested. CONCLUSIONS: These findings suggest that the LEP G2548A genetic polymorphism may increase the susceptibility of cancers in NHL, especially in the homozygote co-dominant model and the additive genetic model among Caucasian populations. The phenomenon also indicates that the SNP functions as a recessive mutation, which needs to be verified or linked with functional studies.

A study on the mechanical characteristics of the EBM-printed Ti-6Al-4V LCP plates in vitro.

PURPOSE: The electron beam melting (EBM) Ti-6Al-4V material technology has been developed over a short time period. It was introduced through a research to develop Ti-6Al-4V implants for patients, but EBM printed locking compression plates have not been used for clinical implants. The main purpose of this study is to find whether the EBM Ti-6Al-4V plate suit for clinical implants. METHODS: First, we scanned an AO-locking compression plate (LCP) and printed LCP samples using EBM. Next, we evaluated the EBM plate surface roughness through optical microscopy as well as the LCP and EBM plates' mechanical characteristics using the ASTM standard, which is commonly used to test the mechanical properties of bone plates subject to bending. Each sample was examined using a single-cycle four-point bending test and hardness testing to acquire data on bending stiffness, bending strength, bending structural stiffness, and hardness. RESULTS: The results show significant differences in bending stiffness, bending strength, bending structural stiffness, and hardness between the samples using EBM and the original LCP plates. The EBM-printed samples' surface roughness was 0.49 ± 0.02 µm. The mean hardness of the LCP sample was 266.67 HV10 ± 5.8, and the EBM-printed sample mean hardness was 341.1 HV10 ± 1.93. The EBM samples' bending stiffness was 87.67%, which is greater than using the LCP plates'; and the bending strength was 190.7% greater, the bending structural stiffness was 73.2% greater, and the hardness was 27.9% greater. CONCLUSIONS: The results show that the EBM plates' general mechanical strength was significantly greater than the LCP plates. An EBM plate is advantageous for clinical implants because it can be customized with great potential for improvement.

Lack of association between LEPR Lys656Asn or Ser343Ser polymorphisms and cancer susceptibility: A meta-analysis.

Previous studies have shown conflicting results between the association of leptin receptor (LEPR) genetic polymorphisms and cancer risk. The frequent LEPR Lys656Asn or Ser343Ser genetic polymorphism has been demonstrated to be functional and may promote genetic susceptibility to cancers. However, the association between the LEPR Lys656Asn or Ser343Ser genetic polymorphism and cancer risk remains to be determined. To improve the understanding of the LEPR Lys656Asn or Ser343Ser genetic polymorphism role in global cancer, a comprehensive meta-analysis was conducted that comprised 2,480 cases and 3,162 controls. The LEPR Lys656Asn or Ser343Ser genetic polymorphism did not significantly affect the cancer risk. In the stratified analysis, there was no significant association of the LEPR Lys656Asn or Ser343Ser variants with any type of cancer under any model. In addition, significantly increased risks were found in the Asian population in heterozygous codominant [odds ratio (OR), 1.24 (1.01-1.53)] and dominant [OR, 1.24 (1.02-1.50)] genetic models. A significantly increased susceptibility to cancer was not found when stratified by study design. There were no significant differences found in genotype method and sample size in cases among the genotypes. These findings indicated a lack of association between LEPR Lys656Asn or Ser343Ser polymorphisms and cancer susceptibility, however, these polymorphisms may increase the cancer susceptibility among the Asian population, particularly in the dominant genetic model. The single-nucleotide polymorphism is also suggested to function as a dominant mutation, which requires verification or association with functional studies.

Association of LEPR K109R polymorphisms with cancer risk: a systematic review and pooled analysis.

PURPOSE: This meta-analysis was conducted to evaluate the association between LEPR K109R (rs1137100) genetic polymorphism and cancer risk. METHODS: To better understand the role of LEPR K109R(rs1137100) genetic polymorphism in global cancer, we conducted this comprehensive meta-analysis encompassing 5819 cases and 8068 controls. RESULTS: Overall, the LEPR K109R(rs1137100) genetic polymorphism did not significantly affect the risk of cancer. In the stratified analysis, significant associations were found between the LEPR K109R(rs1137100) genetic polymorphism and breast cancer under additive genetic model (odds ratio/OR=0.67, 95% CI 0.61-0.73). For prostate cancer, there was no significant association of LEPR K109R(rs1137100) variant with this disease under any model. For lung cancer, there was significant association of LEPR K109R(rs1137100) variant with the disease under heterozygous co-dominant model (OR=0.72, 95% CI 0.55- 0.96), recessive genetic model (OR=0.76, 95% CI 0.61-0.94) and additive genetic model (OR=0.89, 95% CI 0.80-0.99). For gastric cancer, significant association was found in the 3 genetic models (AG vs GG, AA/AG vs GG and A vs G), the ORS (95%CI) being 2.93 (1.25-6.86), 2.93 (1.25-6.86) and 2.25 (1.07-4.72), respectively. Moreover, no significant cancer risk was found in any genetic model among Caucasian and Asian populations. When stratified by study design, no significantly elevated susceptibility to cancer was found among any studies. No significant differences in the genotype method and sample size in cases were found among genotypes. CONCLUSION: These findings suggested that the LEPR K109R(rs1137100) genetic polymorphism may decrease the susceptibility in breast cancer, especially in the additive genetic model. The findings also indicate that single nucleotide polymorphism (SNP) functions as a recessive mutation, which needs to be verified or linked with functional studies.

Lack of association between LEPR Q223R polymorphisms and cancer susceptibility: evidence from a meta-analysis.

PURPOSE: The results from the published studies on the association between LEPR genetic polymorphisms and cancer risk are conflicting. The common LEPR Q223R genetic polymorphism has been reported to be functional and may contribute to genetic susceptibility to cancer. However, the association between LEPR Q223R genetic polymorphism and cancer risk remains inconclusive. METHODS: To better understand the role of LEPR Q223R genetic polymorphism in global cancer, we conducted this comprehensive meta-analysis encompassing 9139 cases and 11282 controls. RESULTS: Overall, the LEPR Q223R genetic polymorphism did not significantly affect the risk of cancer. In the stratified analysis, there was no significant association of LEPR Q223R variant with breast cancer, colorectal cancer and non-Hodgkin's lymphoma (NHL) under any models. Moreover, significantly increased risks were found in Asian and African in all genetic models tested. When stratified by study design, no significantly increased susceptibility to cancer was found among any studies. No significantly differences in sample size in cases were found among genotypes. CONCLUSIONS: These findings suggested lack of association between LEPR Q223R polymorphisms and cancer susceptibility, but the LEPR Q223R genetic polymorphism may increase the susceptibility to cancers in Asian and African individuals. Large, well designed epidemiological studies are needed to validate our findings.

Association of LEP A19G polymorphism with cancer risk: a systematic review and pooled analysis.

The results from the published studies on the association between leptin (LEP) genetic polymorphism and cancer risk are conflicting. The common A19G (rs2167270) genetic polymorphism has been reported to be functional and may contribute to genetic susceptibility to cancers. However, the association between LEP A19G (rs2167270) genetic polymorphism and cancer risk remains inconclusive. To better understand the role of LEP A19G (rs2167270) genetic polymorphism in global cancer, we conducted this comprehensive meta-analysis encompassing 5,679 cases and 7,443 controls. Overall, the LEP A19G (rs2167270) genetic polymorphism was associated with lower cancer risk. In the stratified analysis, significant associations were found between the LEP A19G (rs2167270) genetic polymorphism and colorectal cancer and non-Hodgkin's lymphoma. For colorectal cancer, there was no significant association of LEP A19G (rs2167270) variant with this disease under heterozygous codominant model [odds ratio (OR) = 1.11 (0.97-1.27)], dominant genetic model [OR = 1.03 (0.91-1.17)], and additive genetic model [OR = 0.94 (0.86-1.03)]; however, there was a marginal association under homozygous codominant model [OR = 0.80 (0.66-0.97)] and recessive genetic model [OR = 0.75 (0.63-0.90)]. For non-Hodgkin's lymphoma, there was a significant association of LEP A19G (rs2167270) variant with the disease under homozygous codominant model [OR = 0.74 (0.59-0.94)], recessive genetic model [OR = 0.76 (0.61-0.94)], and additive genetic model [OR = 0.89 (0.80-0.99)], but not under heterozygous codominant model [OR = 0.95 (0.82-1.10)] and dominant genetic model [OR = 0.91 (0.79-1.04)]. Moreover, a significantly decreased cancer risk was found in recessive genetic model among Latin American population. When stratified by study design, significantly elevated susceptibility to cancer was not found among any studies. No significantly differences in genotype method and sample size in cases were found among genotypes. These findings suggest that the LEP A19G (rs2167270) genetic polymorphism may decrease the susceptibility to cancers in colorectal cancer and non-Hodgkin's lymphoma, when assuming a homozygote codominant model and a recessive genetic model among Latin American population. The phenomenon also indicates that the SNP functions as a recessive mutation, which needs to be verified or linked with functional studies.