Association between bariatric surgery with long-term analgesic prescription and all-cause mortality among patients with osteoarthritis: a general population-based cohort study

OBJECTIVES

There is still a large unmet need for novel osteoarthritis (OA) treatments that could provide clinically important effects on long-term pain relief (≥12 months). We examined the relation of bariatric surgery along with weight loss to analgesic prescription and all-cause mortality among individuals with OA.

METHODS

We conducted a cohort study among individuals with OA using The Health Improvement Network. We compared the rate of no analgesic prescription ≥12 consecutive months and the risk of all-cause mortality using inverse probability weighting Cox-proportional hazard models and the difference in number of analgesic prescriptions (non-steroidal anti-inflammatory drugs, opioids, and paracetamol) in the 50^th, 75^th and 90^th percentiles using quantile regression model between bariatric and non-bariatric cohorts.

RESULTS

Included were 588,494 individuals (694 had bariatric surgery). Compared with non-bariatric group, the rate of no analgesic prescription ≥12 consecutive months was higher (HR = 1.23, 95% CI: 1.08-1.38) in bariatric surgery group, and the number of analgesic prescriptions was lower in the 75^th (44 vs 58) and 90^th (74 vs 106) percentiles during a mean follow-up of 4.3 years. All-cause mortality in bariatric surgery group was lower than comparison group (HR = 0.46, 95% CI: 0.41-0.51).

CONCLUSION

This study presents the first evidence that bariatric surgery was associated with decreased long-term analgesic prescription and decreased all-cause mortality among individuals with OA. However, our findings may be overestimated owing to intractable confounding by indication for bariatric surgery; thus, future studies (e.g., clinical trials) are warranted.

Comparative efficacy and safety of acetaminophen, topical and oral non-steroidal anti-inflammatory drugs for knee osteoarthritis: evidence from a network meta-analysis of randomized controlled trials and real-world data

OBJECTIVE

Current global guidelines regarding the first-line analgesics (acetaminophen, topical or oral non-steroidal anti-inflammatory drugs [NSAIDs]) for knee osteoarthritis remain controversial and their comparative risk-benefit profiles have yet to be adequately assessed.

DESIGN

Pubmed, Embase, Cochrane Library, and Web of Science were searched from database inception to March 2021 for randomized controlled trials (RCTs) comparing acetaminophen, topical NSAIDs and oral NSAIDs directly or indirectly in knee osteoarthritis. Bayesian network meta-analyses were conducted. A propensity-score matched cohort study was also conducted among patients with knee osteoarthritis in The Health Improvement Network database.

RESULTS

122 RCTs (47,113 participants) were networked. Topical NSAIDs were superior to acetaminophen (standardized mean difference [SMD] = -0.29, 95% credible interval [CrI]: -0.52 to -0.06) and not statistically different from oral NSAIDs (SMD = 0.03, 95% CrI: -0.16 to 0.22) for function. It had lower risk of gastrointestinal adverse effects (AEs) than acetaminophen (risk ratio [RR] = 0.52, 95%CrI: 0.35 to 0.76) and oral NSAIDs (RR = 0.46, 95%CrI: 0.34 to 0.61) in RCTs. In real-world data, topical NSAIDs showed lower risks of all-cause mortality (hazard ratio [HR] = 0.59, 95% confidence interval [CI]: 0.52 to 0.68), cardiovascular diseases (HR = 0.73, 95%CI: 0.63 to 0.85) and gastrointestinal bleeding (HR = 0.53, 95%CI: 0.41 to 0.69) than acetaminophen during the one-year follow-up (n = 22,158 participants/group). A better safety profile was also observed for topical than oral NSAIDs (n = 14,218 participants/group).

CONCLUSIONS

Topical NSAIDs are more effective than acetaminophen but not oral NSAIDs for function improvement in people with knee osteoarthritis. Topical NSAIDs are safer than acetaminophen or oral NSAIDs in trials and real-world data.

[The clinical effects of oral contraceptive pretreatment on the outcome of gonadotropin releasing hormone antagonist protocol in non-polycystic ovary syndrome patients]

Objective: To evaluate the clinical effect of oral contraceptive (OC) pretreatment on the outcome of gonadotropin releasing hormone antagonist (GnRH-a) protocol in patients with non-polycystic ovary syndrome. Methods: From January 2017 to May 2019, a total of 436 patients undergoing in vitro fertilization and embryo transfer/Intracytoplasmic sperm injection (IVF-ET/ICSI) treatment in Peking University First Hospital reproductive center clinic were included in this retrospective cohort study. A total of 144 patients (147 cycles) used OC pretreatment prior to GnRH-a protocol and 292 patients (306 cycles) used GnRH-a protocol without OC pretreatment. The drug usage as well as pregnant outcomes between groups were examined. The primary outcome was the cumulative clinical pregnancy rate of oocyte retrieval cycle and the secondary outcome included the number of oocytes, MⅡ oocytes, embryos and clinical pregnancy rate of fresh embryo transfer cycle. Results: The median ages (and Q₁, Q₃) of OC pretreatment group and non-OC group were 33 (30,36) and 34 (30,38) years old, respectively. The number of MⅡ oocytes was higher in OC pretreatment group (7/9) than in non-OC group (6/8) (P=0.002). The significant difference were not found in the cumulative clinical pregnancy rate of each oocyte retrieval cycle (61.7% vs 54.6%), the clinical pregnancy rate of fresh embryo transfer cycle (34.4% vs 35.6%), and the number of oocytes (9 vs 8) and embryos (6 vs 6) between groups. Conclusion: Our findings suggest that compared to non-OC pretreatment group, pretreatment with OC is associated with more MⅡ oocytes, and with an increasing trend of the cumulative clinical pregnancy rate in non-polycystic ovary syndrome patients undergoing fresh IVF-ET/ICSI.

Does smoking cessation increase risk of knee replacement? a general population-based cohort study

OBJECTIVE

Smoking represents a major issue for global public health. Owing to methodologic challenges, findings of an association between smoking and risk of knee osteoarthritis (OA) are inconsistent. We sought to assess the relation of onset of smoking cessation to the risk of OA sequelae, i.e., knee replacement, and to perform sub-cohort analysis according to weight change after smoking cessation.

DESIGN

Using The Health Improvement Network, we conducted a cohort study to examine the association between smoking cessation and risk of knee replacement among patients with knee OA. Participants who stopped smoking were further grouped into three sub-cohorts: weight gain (body mass index [BMI] increased>1.14 kg/m²), no substantial weight change (absolute value of BMI change<1.14 kg/m²), and weight loss (BMI loss>1.14 kg/m²) after smoking cessation.

RESULTS

We identified 108 cases of knee replacement among 1,054 recent quitters (26.7/1,000 person-years) and 1,108 cases among 15,765 current smokers (17.4/1,000 person-years). The rate difference of knee replacement in recent quitter cohort vs current smoker cohort was 10.4 (95% confidence interval [CI]:5.3-15.6)/1,000 person-years and the adjusted hazard ratio (HR) was 1.30 (95%CI:1.05-1.59). Compared with current smokers, risk of knee replacement was higher among quitters with weight gain (HR = 1.42,95%CI:1.01-1.98), but not among those with no substantial weight change (HR = 1.29,95%CI:0.90-1.83) or those with weight loss (HR = 1.11,95%CI:0.71-1.75).

CONCLUSIONS

Our large population-based cohort study provides the first evidence that smoking cessation was associated with a higher risk of knee replacement among individuals with knee OA, and such an association was due to weight gain after smoking cessation.

Novel variants and uncommon cases among southern Chinese children with X-linked hypophosphatemia

PURPOSE

X-linked hypophosphatemia (XLH) is the most common inherited renal phosphate wasting disorder and is often misdiagnosed as vitamin D deficiency. This study aims to provide clinical and mutational characteristics of 65 XLH pediatric patients in southern China.

METHODS

In this work, a combination of DNA sequencing and qPCR analysis was used to study the PHEX gene in 80 pediatric patients diagnosed with hypophosphatemia. The clinical and laboratory data of confirmed 65 XLH patients were assessed and analyzed retrospectively.

RESULTS

In 65 XLH patients from 61 families, 51 different variants in the PHEX gene were identified, including 23 previously reported variants and 28 novel variants. In this cohort of XLH patients, the c.1601C>T(p.Pro534Leu) variant appears more frequently. Fourteen uncommon XLH cases were described, including four boys with de novo mosaic variants, eight patients with large deletions and a pair of monozygotic twins. The clinical manifestations in this cohort are very similar to those previously reported.

CONCLUSION

This study extends the mutational spectrum of the PHEX gene, which will contribute to accurate diagnosis. This study also suggests a supplementary qPCR or MLPA assay may be performed along with classical sequencing to confirm the gross insertion/deletion.

SAT0453 DELAYED DENOSUMAB INJECTIONS AND FRACTURES RISK AMONG SUBJECTS WITH OSTEOPOROSIS: A POPULATION-BASED COHORT STUDY

Background:

Denosumab is effective for osteoporosis, but discontinuation leads to rapid reversal of its therapeutic effect[1].

Objectives:

To estimate the risk for fracture among users of denosumab who delayed subsequent dosages compared with users who received dosages on time.

Methods:

Population-based cohort study. We included patients aged over 45 years who initiated denosumab for osteoporosis from UK THIN database, 2010 to 2019. Observational data were used to “emulate a hypothetical trial”[2, 3] with three dosing intervals: subsequent denosumab injection 24-28 weeks after prior dose (“on time”), delay by 4-16 weeks (“short delay”), and delay by over 16 weeks (“long delay”). The primary outcome was a composite of all fracture types. Secondary outcomes included major osteoporotic fracture, vertebral fracture, and hip fracture.

Results:

The rate of composite fracture per 1000 person-years was 58.9 for on-time, 61.7 for short delay, and 85.4 for long delay of subsequent denosumab injections. Compared to on-time injections, short delay had a hazard ratio (HR) for composite fracture 1.03 (95% CI 0.63-1.69) and long delay HR 1.44 (95% CI 0.96-2.17; p for trend 0.093). For major osteoporotic fractures, short delay had an HR 0.94 (95% CI 0.57-1.55) and long delay an HR of 1.69 (95% CI 1.01-2.83; p for trend 0.056). For vertebral fractures, short delay had an HR 1.48 (95% CI 0.58-3.79) and long delay 3.91 (95% CI 1.62-9.45; p for trend 0.005).

Conclusion:

While delayed subsequent denosumab dosages over 16 weeks was associated with an increased risk of vertebral and major osteoporotic fracture compared to no delay, composite fracture risk was not increased with longer delays.

References:

[1]Cummings SR, Ferrari S, Eastell R, et al. Vertebral Fractures After Discontinuation of Denosumab: A Post Hoc Analysis of the Randomized Placebo-Controlled FREEDOM Trial and Its Extension. J Bone Miner Res, 2017.

[2]Hernán MA. How to estimate the effect of treatment duration on survival outcomes using observational data. BMJ 2018.

[3]Hernán MA, Robins JM. Using Big Data to Emulate a Target Trial When a Randomized Trial Is Not Available. Am J Epidemiol 2016.

Table.

Rates and Adjusted Hazard Ratios of Fracture

On-timeShort delayLong delayP for linear trendComposite FractureRate (per 1000 person-years)5961.785.4-Unadjusted HR (95 %)Ref1.05 (0.62, 1.76)1.45 (0.95, 2.21)0.097Adjusted HR (95% CI)†Ref1.03 (0.63, 1.69)1.44 (0.96, 2.17)0.093Major Osteoporotic FractureRate (per 1000 person-years)34.831.958-Unadjusted HR (95 %)Ref0.92 (0.55, 1.53)1.67 (0.98, 2.84)0.074Adjusted HR (95% CI)†Ref0.94 (0.57, 1.55)1.69 (1.01, 2.83)0.056Vertebral FractureRate (per 1000 person-years)4.97.319.4-Unadjusted HR (95 %)Ref1.47 (0.58, 3.71)3.93 (1.59, 9.72)0.006Adjusted HR (95% CI)†Ref1.48 (0.58, 3.79)3.91 (1.62, 9.45)0.005Hip FractureRate (per 1000 person-years)10.29.618.3-Unadjusted HR (95 %)Ref0.94 (0.43, 2.04)1.78 (0.80, 3.97)0.18Adjusted HR (95% CI)†Ref0.97 (0.44, 2.12)1.75 (0.81, 3.79)0.173

†Adjusted model: adjusted by age, sex, baseline CCI index, major osteoporotic fracture, oral BP duration (years), 10-year risk of major osteoporotic fracture, prior denosumab doses.

Acknowledgments:

We acknowledge Dr. Dani Prieto-Alhambra for kindly providing Read codes.

Disclosure of Interests:

Houchen Lyu: None declared, Kazuki Yoshida: None declared, Sizheng Steven Zhao: None declared, Xabier García-Albéniz: None declared, Jie Wei: None declared, Chao Zeng: None declared, Sara Tedeschi: None declared, Benjamin Leder Grant/research support from: Research funding from Amgen, Guanghua Lei: None declared, Peifu Tang: None declared, Daniel Solomon Grant/research support from: Funding from Abbvie and Amgen unrelated to this work

Gut Microbiota Composition Associated With Clostridium difficile-Positive Diarrhea and C. difficile Type in ICU Patients

The gut microbiota composition of intensive care unit (ICU) patients suffering from Clostridium difficile-positive diarrhea (CDpD) is poorly understood. This prospective study aims to use 16S rDNA (and metagenome) sequencing to compare the microbiota composition of 58 (and 5) ICU patients with CDpD (CDpD group), 33 (and 4) ICU patients with C. difficile-negative diarrhea (CDnD group), and 21 (and 5) healthy control subjects (control group), as well as CDpD patients in the A⁺B⁺ (N = 34; A/B: C. difficile TcdA/B), A⁻B⁺ (N = 7), and A⁻B⁻ (N = 17) subgroups. For 16S rDNA data, OTU clustering (tool: UPARSE), taxonomic assignment (tool: RDP classifier), α-diversity, and β-diversity analyses (tool: QIIME) were conducted. For metagenome data, metagenome assembly (tool: SOAPdenovo), gene calling (tools: MetaGeneMark, CD-HIT, and SoapAligner), unigene alignment (tool: DIAMOND), taxon difference analysis (tool: Metastats), and gene annotation (tool: DIAMOND) were performed. The microbial diversity of the CDpD group was lower than that of the CDnD and control groups. The abundances of 10 taxa (e.g., Deferribacteres, Cryptomycota, Acetothermia) were significantly higher in the CDpD group than in the CDnD group. The abundances of Saccharomycetes and Clostridia were significantly lower in CDpD in comparison with control. Some taxa were significantly different between the A⁺B⁺ and A⁻B⁻ subgroups. CDpD might relate to a decrease in beneficial taxa (i.e., Saccharomycetes and Clostridia) and an increase in harmful taxa (e.g., Deferribacteres, Cryptomycota, Acetothermia) in gut microbiota of ICU patients. C. difficile toxin type might be slightly associated with gut microbiota composition.

[Application of combined angiography in diagnosis and treatment of carotid artery stenosis]

Objective: To evaluate the safety and clinical value of combined cardiac and cerebral angiography in the diagnosis and treatment of patients with carotid artery stenosis. Methods: Clinical data of patients from May 2016 to June 2019 were collected. The patient underwent combined angiography under local anesthesia. Clinical characteristics, prognosisand complications were retrospectively analyzed. Results: A total of 45 patients with carotid artery stenosis received combined angiography, among which 12 patients had no obvious carotid artery stenosis. There were 22 cases with unilateral carotid artery stenosis, including 12 cases with mild stenosis and 10 cases with moderate to severe stenosis. There were 11 cases of bilateral stenosis, including 3 cases with mild stenosis and 8 cases with moderate to severe stenosis. 12 patients had no obvious stenosis incoronary arteries, 11 patients had single-vessel disease, 7 patients had 2-vessel disease, and 15 patients had 3-vessel disease. In the whole group of patients, surgical indications are available of 18 patients with carotid artery stenosis, 4 of the mreceived combined therapy. 2 of them under went Carotid Endarterectomy (CEA)+Percutaneous Transluminal Coronary Intervention (PCI), 2 under went Carotid Artery Stenting (CAS)+PCI. CAS+coronary artery angiography was performed in 3 cases. CEA+coronary angiography was performed in 5 cases. 5 patients received conservative treatment after combined angiography. In one case, the condition of coronary artery was so complicated that PCI was performed firstly. No cardiac or cerebrovascular complications such as myocardial infarction or cerebral infarction occurred during perioperative period. Conclusion: Combined cardio-cerebrovascular angiography is a good method to evaluate the cardiovascular and cerebrovascular in the diagnosis and treatment of patients with carotid artery stenosis, which can provide a clear diagnosis for treatment with a low complications frequency.

[Simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease]

Objective: To implement simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease (CAD), we sought to investigate its efficacy of reducing perioperative major adverse cardiac and cerebrovascular event (MACCE). Methods: Brain-and-Heart treatment team in Peking University International Hospital performed hybrid Digital Substraction Angiography (DSA) of carotid artery and coronary artery for 37 patients meeting the group criterion from September 2017 to February 2019.Twelve patients were diagnosed and received simultaneous treatments of severe carotid artery stenosis and coronary artery disease after hybrid DSA. We conducted the retrospective study and made analysis of these patients. Results: The diagnosis rate by simultaneous treatmentsin patients with carotid artery stenosis and coronary artery disease is 59.5% (22/37), the rate of severe carotid artery stenosis or multi-vessel CAD is 77.3% (17/22).The rate of severe carotid artery stenosis with CAD is 54.5% (12/22), therate of simultaneous treatmentsis 83.3%(10/12). Nine patients post-operative symptoms release, one patient with ischemic stroke after CABG, and two patients of medical therapy with stable symptoms. Conclusion: Simultaneous treatments in patients with severe carotid artery stenosis and coronary artery disease not only reveal the positive correlation between carotid stenosis and CAD, but also accurately evaluate severity degree or rapidly formulate scheme and reduce MACCE.

Estrogen receptor β activation ameliorates DSS-induced chronic colitis by inhibiting inflammation and promoting Treg differentiation

Estrogen receptor (ER) β activation has anti-inflammatory activity. However, its effect on the development of inflammatory bowel disease (IBD) and the underlying mechanism have not been clarified. This study aimed to assess the clinical value of ERβ⁺CD4⁺ T cells in IBD patients and examine the anti-inflammatory role of ERβ activation in dextran sulfate sodium (DSS)-induced chronic colitis in mice. We investigated the effects of ERB041 (an ERβ-specific agonist) on inflammatory cytokines and pro-inflammatory T-cell and regulatory T-cell (Treg) responses in murine colitis. We tested the role of ERβ activation on Treg differentiation and its activity to suppress T-cell proliferation in vitro. We found that reduced frequency of circulating ERβ⁺CD4⁺ T cells in IBD patients was negatively correlated with inflammation and disease severity. ERβ and FoxP3 expression co-localized in the intestinal tissues of IBD patients. Treatment with ERB041 significantly mitigated colitis-induced weight loss, inflammation, and disease severity. It also restored the ERβ⁺CD4⁺ T cell population in the spleen and colon lamina propria of these mice. ERB041 treatment inhibited CD4⁺CD25^- and CD8⁺ T cell infiltration and restored Tregs and activated T-cell immunoreceptor with Ig and ITIM domains (TIGIT)⁺ Tregs in the colon lamina propria. In vitro, we found that ERβ activation enhanced Treg differentiation, immunosuppression, and TGF-β1/Smad signaling in CD4⁺ T cells. Our data suggest that ERβ⁺CD4⁺ T cells represent a potential biomarker for evaluating IBD disease severity, and ERβ activation may be valuable for the treatment of IBD by enhancing the Treg response.

Thiazide diuretics and risk of knee replacement surgery among patients with knee osteoarthritis: a general population-based cohort study

OBJECTIVE

Thiazide diuretic use is associated with higher bone mineral density (BMD) and possibly lower serum magnesium levels than loop diuretic use, and both high BMD and low serum magnesium have been linked to high prevalent knee osteoarthritis. This study aimed to compare the risk of a clinically relevant endpoint, knee replacement (KR) surgery, among initiators of thiazide and loop diuretics.

DESIGN

Among patients aged ≥50 years with a diagnosis of knee osteoarthritis in The Health Improvement Network (THIN) in United Kingdom, we conducted a propensity score-matched cohort study to examine the relation of thiazide diuretic initiation vs loop diuretic initiation to the risk of KR over 5 years.

RESULTS

Among thiazide and loop diuretic initiators (n = 3,488 for each group; mean age: 73 years; female ratio: 59%), 359 (28.6/1,000 person-years) and 283 (24.1/1,000 person-years) KRs occurred during the follow-up period, respectively. The hazard ratio (HR) of KR for thiazide diuretic initiation vs loop diuretic initiation was 1.26 (95% confidence interval [CI]: 1.08-1.47). The adherence-adjusted HR of KR for continuous use of thiazide diuretics was 1.44 (95% CI: 1.21-1.72).

CONCLUSIONS

In this population-based cohort of patients with knee osteoarthritis, thiazide diuretic use was associated with a higher risk of KR than loop diuretic use. This association may potentially be due to thiazide diuretics' effect on BMD and serum magnesium.

Intra-articular corticosteroids and the risk of knee osteoarthritis progression: results from the Osteoarthritis Initiative

OBJECTIVE

A recent randomized clinical trial reported that repeated intra-articular corticosteroids (IACs) were associated with a greater cartilage loss. This study aimed to examine the relation of IACs to knee radiographic osteoarthritis (ROA) progression in a real-world setting.

DESIGN

A cohort that initiated IACs and a comparison cohort without IACs from participants with mild to moderate knee ROA in the Osteoarthritis Initiative (OAI) were assembled (from 0-month to 48-month). Two measures of knee ROA progression were assessed during the follow-up period: (1) an increase in Kellgren and Lawrence (KL) grade by ≥1 grade or having a knee replacement (i.e., KL grade worsening); and (2) a decrease in joint space width (JSW) by ≥0.7 mm or having a knee replacement (i.e., JSW worsening). The associations of IACs initiation using a propensity-score matched cohort study and continuous IACs using marginal structural models with the risk of knee ROA progression were examined.

RESULTS

Among 684 propensity-score matched participants at baseline (148 IACs initiators, 536 comparators), 65 knees (21.7/100 person-years) in the IACs initiation cohort and 90 knees (7.1/100 person-years) in the comparison cohort experienced KL worsening. The hazard ratios (HRs) of KL worsening from IACs initiation and continuous IACs were 3.02 (95% confidence interval [CI], 2.19-4.16) and 4.67 (95% CI, 2.92-7.47), respectively. The corresponding HRs of JSW worsening were 2.93 (95% CI, 2.13-4.02) and 3.26 (95% CI, 1.78-5.96), respectively. All HRs for continuous use of IACs were further away from the null.

CONCLUSIONS

IACs, especially continuous IACs, may be associated with an increased risk of knee ROA progression.

[Vascular endothelial growth factor is up-regulated by leukemia inhibitory factor and interleukin-6 in human endometriotic stromal cells]

Objective: To compare the expression of leukemia inhibitory factor (LIF), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in tissue and fluid samples from patients with endometriosis, and investigate whether LIF and IL-6 regulate VEGF in human endometriotic stromal cells (ESC). Methods: The levels of VEGF, LIF, IL-6 in serum, peritoneal fluid of patients with and without endometriosis were measured by ELISA. The mRNA of these three factors in the ectopic and eutopic endometrial tissue and stromal cells were measured by real-time PCR. ESC derived from ovarian endometriomas were cultured using the method of primary cell culture with LIF and IL-6, and the level of VEGF mRNA and protein were measured by the method of real-time PCR and ELISA respectively. Results: VEGF and IL-6 concentration were 1.2 and 1.3 times higher in the serum of patients with endometriosis than in the control group [(94±19) versus (78±17) ng/L; (45±14) versus (35±9) ng/L; all P<0.05]. VEGF and IL-6 concentration were 1.2 and 1.4 times higher in the peritoneal fluid of patients with endometriosis than in the control group [(110±25) versus (91±21) ng/L; (69±20) versus (49±15) ng/L; all P<0.05]. VEGF and IL-6 concentrations in peritoneal fluid of patients with endometriosis were 1.2 and 1.5 times higher than in serum (all P<0.01). VEGF, LIF and IL-6 mRNA expression were 2.2, 8.6, 44.7 times higher in ESC compared with the matching eutopic endometrial stromal cells (all P<0.01). LIF and IL-6 mRNA were 2.0 and 64.8 times higher in ectopic endometrial tissue than the matching eutopic endometrial tissue (all P<0.05).ESC cultured with LIF, IL-6 and LIF+IL-6 induce VEGF protein secretion [(106±18), (124±30), (140±27) ng/L] by 1.3, 1.5 and 1.7 times (all P<0.05). Conclusion: Overexpression of LIF and IL-6 may synergistically contribute to upregulation of VEGF in ESC and promote development of endometriosis.

Risk factor heterogeneity for medial and lateral compartment knee osteoarthritis: analysis of two prospective cohorts

OBJECTIVE

To evaluate the etiologic heterogeneity between medial and lateral tibiofemoral radiographic osteoarthritis (ROA).

METHODS

Knees without medial or lateral tibiofemoral ROA at baseline were followed for 60-month in Multicenter Osteoarthritis Study (MOST) and for 48-month in Osteoarthritis Initiative (OAI). We examined the relation of previously reported risk factors to incident medial and lateral tibiofemoral ROA separately and determined the etiology heterogeneity with a ratio of rate ratios (RRs) (i.e., the RR for medial tibiofemoral ROA divided by the RR for lateral tibiofemoral ROA) using a duplication method for Cox proportional hazard regression.

RESULTS

Of 2,016 participants in MOST, 436 and 162 knees developed medial or lateral tibiofemoral ROA, respectively. Obesity and varus malalignment were 95% and 466% more strongly associated with incident medial tibiofemoral ROA than with lateral tibiofemoral ROA, respectively (ratios of RRs, 1.95 [95% confidence interval (CI):1.05-3.62] and 5.66 [95% CI:3.20-10.0]). In contrast, the associations of female sex and valgus malalignment with incident medial tibiofemoral ROA were weaker or in an opposite direction compared with lateral tibiofemoral Osteoarthritis (OA) (ratios of RRs, 0.40 [95% CI:0.26-0.63] and 0.20 [95% CI:0.12-0.34], respectively). Older age tended to show a weaker association with incident medial tibiofemoral ROA than with incident lateral tibiofemoral ROA. No heterogeneity was observed for the relation of race, knee injury, or contralateral knee ROA. These findings were closely replicated in OAI.

CONCLUSION

Risk factor profiles for medial and lateral tibiofemoral ROA are different. These results can provide a framework for the development of targeted prevention and potential treatment strategies for specific knee OA subtypes.