The prevalence of and demographic factors associated with radiographic knee osteoarthritis in Korean adults aged ? 50 years: The 2010-2013 Korea National Health and Nutrition Examination Survey.
ABSTRACT: BACKGROUND:To reduce the social burden of knee osteoarthritis (OA) by addressing it in the early stages in the population at greatest risk, the epidemiology of knee OA needs to be understood and associated demographic factors need to be identified. OBJECTIVES:We evaluated the weighted prevalence of and demographic factors associated with radiographic knee OA in Korean adults. METHODS:We analyzed data from 12,287 individuals aged ? 50 years who had radiographs of the knee taken in the 2010-2013 Korea National Health and Nutrition Examination Survey (KNHANES). Radiographic knee OA was defined based on the Kellgren-Lawrence grade, as follows: 0: No abnormal finding 1: Mild degenerative changes, minute osteophytes 2: Mild knee OA, definite osteophytes 3: Moderate knee OA, moderate joint-space narrowing and definite osteophytes 4: Severe knee OA, severe joint-space narrowing with subchondral sclerosis. RESULTS:We found that the prevalence of radiographic knee OA in the Korean adult population was 35.1%. Logistic regression analyses were performed to identify factors associated independently with radiographic knee OA, with age, sex, area of residence, education level, household income, and obesity serving as covariates. Women were at greater risk than men of having knee OA (OR 2.12, 95% CI 1.90-2.37, p < 0.001). Compared with subjects aged 50-59 years, adults aged ? 80 years were at 8.87-fold (95% CI 7.12-11.06, p < 0.001) greater risk of having knee OA. Residence in a rural area was associated with a greater risk of having radiographic knee OA than was residence in an urban area (OR 1.26, 95% CI 1.08-1.48, p = 0.004), regardless of knee OA severity (Kellgren-Lawrence grades ?2, ?3, and 4). Elementary school graduates had 1.71-fold (p < 0.001) greater risks of having knee OA than did college graduates. Household incomes ?24th percentile were associated with a greater risk of having knee OA compared with those ?75th percentile (OR 1.28, 95% CI 1.08-1.52, p = 0.004). Obesity was associated with an approximately two-fold greater risk of knee OA, regardless of knee OA severity (Kellgren-Lawrence grades ?2, ?3, and 4). CONCLUSIONS:Using data from the 2010-2013 KNHANES and defining knee OA as Kellgren-Lawrence grade ? 2, we found that the prevalence of radiographic knee OA was 35.1% (24.4% in men, 44.3% in women) in a representative sample of Korean adults aged ? 50 years, with the highest prevalence (78.7%) observed in women aged ? 80 years. Low socioeconomic status and traditional factors, including age, female sex, and obesity, were associated with the risk of knee OA.
Project description:We previously reported an association between high bone mass (HBM) and a bone-forming phenotype of radiographic hip osteoarthritis (OA). As knee and hip OA have distinct risk factors, in this study we aimed to determine (i) whether HBM is also associated with knee OA, and (ii) whether the HBM knee OA phenotype demonstrates a similar pattern of radiographic features to that observed at the hip. HBM cases (defined by DXA BMD Z-scores) from the UK-based HBM study were compared with unaffected family controls and general population controls from the Chingford and Hertfordshire cohort studies. A single blinded observer graded AP weight-bearing knee radiographs for features of OA (Kellgren-Lawrence score, osteophytes, joint space narrowing (JSN), sclerosis) using an atlas. Analyses used logistic regression, adjusting a priori for age and gender, and additionally for BMI as a potential mediator of the HBM-OA association, using Stata v12. 609 HBM knees in 311 cases (mean age 60.8years, 74% female) and 1937 control knees in 991 controls (63.4years, 81% female) were analysed. The prevalence of radiographic knee OA, defined as Kellgren-Lawrence grade?2, was increased in cases (31.5% vs. 20.9%), with age and gender adjusted OR [95% CI] 2.38 [1.81, 3.14], p<0.001. The association between HBM and osteophytosis was stronger than that for JSN, both before and after adjustment for BMI which attenuated the ORs for knee OA and osteophytes in cases vs. controls by approximately 50%. Our findings support a positive association between HBM and knee OA. This association was strongest for osteophytes, suggesting HBM confers a general predisposition to a subtype of OA characterised by increased bone formation.
Project description:OBJECTIVES:To determine whether greater effusion-synovitis volume and infrapatellar fat pad (IFP) signal intensity alteration differentiate incident accelerated knee OA (KOA) from a gradual onset of KOA or no KOA. METHODS:We classified three sex-matched groups of participants in the Osteoarthritis Initiative who had a knee with no radiographic KOA at baseline (recruited 2004-06; Kellgren-Lawrence <2; n = 125/group): accelerated KOA: ⩾1 knee progressed to Kellgren-Lawrence grade ⩾3 within 48 months; common KOA: ⩾1 knee increased in radiographic scoring within 48 months; and no KOA: both knees had the same Kellgren-Lawrence grade at baseline and 48 months. The observation period included up to 2 years before and after when the group criteria were met. Two musculoskeletal radiologists reported presence of IFP signal intensity alteration and independent readers used a semi-automated method to segment effusion-synovitis volume. We used generalized linear mixed models with group and time as independent variables, as well as testing a group-by-time interaction. RESULTS:Starting at 2 years before disease onset, adults who developed accelerated KOA had greater effusion-synovitis volume than their peers (accelerated KOA: 11.94 ± 0.90 cm3, KOA: 8.29 ± 1.19 cm3, no KOA: 8.14 ± 0.90 cm3) and have greater odds of having IFP signal intensity alteration than those with no KOA (odds ratio = 2.07, 95% CI = 1.14-3.78). Starting at 1 year prior to disease onset, those with accelerated KOA have greater than twice the odds of having IFP signal intensity alteration than those with common KOA. CONCLUSION:People with IFP signal intensity alteration and/or greater effusion-synovitis volume in the absence of radiographic KOA may be at high risk for accelerated KOA, which may be characterized by local inflammation.
Project description:OBJECTIVE:To develop and internally validate risk models and a clinical risk score tool to predict incident radiographic knee osteoarthritis (RKOA) in middle-aged women. METHODS:We analyzed 649 women in the Chingford 1,000 Women study. The outcome was incident RKOA, defined as Kellgren/Lawrence grade 0-1 at baseline and ?2 at year 5. We estimated predictors' effects on the outcome using logistic regression models. Two models were generated. The clinical model considered patient characteristics, medication, biomarkers, and knee symptoms. The radiographic model considered the same factors, plus radiographic factors (e.g., angle between the acetabular roof and the ilium's vertical cortex [hip ?-angle]). The models were internally validated. Model performance was assessed using calibration and discrimination (area under the receiver characteristic curve [AUC]). RESULTS:The clinical model contained age, quadriceps circumference, and a cartilage degradation marker (C-terminal telopeptide of type II collagen) as predictors (AUC = 0.692). The radiographic model contained older age, greater quadriceps circumference, knee pain, knee baseline Kellgren/Lawrence grade 1 (versus 0), greater hip ?-angle, greater spinal bone mineral density, and contralateral RKOA at baseline as predictors (AUC = 0.797). Calibration tests showed good agreement between the observed and predicted incident RKOA. A clinical risk score tool was developed from the clinical model. CONCLUSION:Two models predicting incident RKOA within 4 years were developed, including radiographic variables that improved model performance. First-time predictor hip ?-angle and contralateral RKOA suggest OA origins beyond the knee. The clinical tool has the potential to help physicians identify patients at risk of RKOA in routine practice, but the tool should be externally validated.
Project description:The purpose of this study was to assess the concurrent validity and sensitivity to change of three knee osteoarthritis (OA) grading scales. The Kellgren-Lawrence (KL) and the Osteoarthritis Research Society International (OARSI) joint space narrowing (JSN) grading scales are well-established. The third scale, the compartmental grading scale for OA (CG) is a novel scale which grades JSN, femoral osteophytes, tibial erosion and subluxation to create a total score.One sample of 72 posteroanterior (PA) fixed-flexion radiographs displaying mild to moderate knee OA was selected from the Multicenter Osteoarthritis Study (MOST) to study validity. A second sample of 75 radiograph pairs, which showed an increase in OA severity over 30 months, was selected to study sensitivity to change. The three radiographic grading scales were applied to each radiograph in both samples. Spearman's rank correlation coefficients were used to correlate the radiographic grades and the change in grades over 30 months with a Whole-organ Magnetic Resonance Imaging Score (WORMS)-based composite score which included five articular features of knee OA.Correlations between the KL, OARSI JSN and CG grading scales and the magnetic resonance image (MRI)-based score were 0.836, 0.840 and 0.773 (P < 0.0001) respectively while correlations between change in the radiographic grading scales and change in the MRI-based score were 0.501, 0.525 and 0.492 (P < 0.0001).All three radiographic grading scales showed high validity and are suitable to assess knee OA severity. They showed moderate sensitivity to change; therefore caution should be taken when using ordinal radiographic grading scales to monitor knee OA over time.
Project description:A lack of biomarkers that identify patients at risk for severe osteoarthritis (OA) complicates development of disease-modifying OA drugs.To determine whether inflammatory genetic markers could stratify patients with knee OA into high and low risk for destructive disease.Genotype associations with knee OA severity were assessed in two Caucasian populations. Fifteen single nucleotide polymorphisms (SNPs) in six inflammatory genes were evaluated for association with radiographic severity and with synovial fluid mediators in a subset of the patients.Interleukin 1 receptor antagonist (IL1RN) SNPs (rs419598, rs315952 and rs9005) predicted Kellgren-Lawrence scores independently in each population. One IL1RN haplotype was associated with lower odds of radiographic severity (OR=0.15; 95% CI 0.065 to 0.349; p<0.0001), greater joint space width and lower synovial fluid cytokine levels. Carriage of the IL1RN haplotype influenced the age relationship with severity.IL1RN polymorphisms reproducibly contribute to disease severity in knee OA and may be useful biomarkers for patient selection in disease-modifying OA drug trials.
Project description:Objectives:To estimate the multi-dimensional health impact of radiographic knee OA and quantify the overall health-related quality of life (HRQoL) burden, using a preference-based health utilities measure. Methods:Data on self-reported HRQoL, measured using the SF-12 multi-dimensional health state instrument, were obtained for 2895 patients with radiographic knee OA (Kellgren-Lawrence grade of at least 2) from the Osteoarthritis Initiative and for a general population sample of 3202 from the National Health Measurement Study. The SF-12 was converted to the six-dimensional SF-6D classification to compute preference-based health utilities. Generalized ordinal regression and multinomial regression were used to estimate the health loss on each SF-6D dimension for Osteoarthritis Initiative participants with radiographic knee OA relative to the general population, adjusted for differences in age, BMI, sex, ethnicity and educational level. Predicted SF-6D profiles were then used to compute the average HRQoL loss attributable to radiographic knee OA. Results:Radiographic knee OA was associated with substantial health losses on all dimensions of the SF-6D except for social functioning. Health losses increased with the radiographic severity of OA in dimensions related to physical health, while there was no relationship between worse radiographic disease and worse self-assessed health in mental and emotional dimensions of health. Overall, radiographic knee OA was associated with a HRQoL detriment of 0.040-0.044 at Kellgren-Lawrence grade 2, increasing to 0.045-0.050 at grade 3 and 0.073-0.081 at grade 4. Conclusion:Radiographic knee OA is significantly associated with worse HRQoL across most dimensions of health.
Project description:To examine the relationship of knee osteoarthritis (OA) with cardiovascular and metabolic risk factors by obesity status and gender.Data from 1,066 National Health and Nutrition Examination Survey III participants (?60 years of age) was used to examine relationships of osteophytes-defined radiographic knee OA and cardiovascular and metabolic measures. Analyses were considered among obese [body mass index (BMI)?30 kg/m(2)] and non-obese (BMI<30 kg/m(2)) men and women.The prevalence of osteophytes-defined radiographic knee OA was 34%. Leptin levels and homeostatic model assessment-insulin resistance (HOMA-IR), a proxy measure of insulin resistance, were significantly associated with knee OA; those with knee OA had 35% higher HOMA-IR values and 52% higher leptin levels compared to those without knee OA. The magnitude of the association between HOMA-IR and knee OA was strongest among men, regardless of obesity status; odds ratios (ORs) for HOMA-IR were 34% greater among non-obese men (OR=1.18) vs obese women (OR=0.88). Among obese women, a 5-?g/L higher leptin was associated with nearly 30% higher odds of having knee OA (OR=1.28). Among men, ORs for the association of leptin and knee OA were in the opposite direction.Cardiometabolic dysfunction is related to osteophytes-defined radiographic knee OA prevalence and persists within subgroups defined by obesity status and gender. A sex dimorphism in the direction and magnitude of cardiometabolic risk factors with respect to knee OA was described including HOMA-IR being associated with OA prevalence among men while leptin levels were most important among women.
Project description:The etiology of degenerative meniscus tear is unclear but could be related to a generalized osteoarthritic disease process. We studied whether radiographic hand osteoarthritis (OA) is associated with meniscus damage.We examined 974 persons aged 50-90 years drawn via census tract data and random-digit dialing from Framingham, Massachusetts, United States. One reader assessed bilateral hand radiographs (30 joints) and another read frontal knee radiographs, all according to the Kellgren-Lawrence (KL) scale. A third reader assessed right knee 1.5-T magnetic resonance imaging (MRI) scans for meniscus damage. We calculated the prevalence of medial and/or lateral meniscus damage in those with one to two and three or more finger joints with radiographic OA (KL grade ?2) compared to those without radiographic hand OA with adjustment for age, sex, and body mass index. We also evaluated the above association in persons without evidence of radiographic OA (KL grade 0) in their knee (n = 748).The prevalence of meniscus damage in the knee of subjects with no, one to two, and three or more finger joints with OA was 24.9%, 31.7%, and 47.2%, respectively. The adjusted prevalence ratio (PR) of having meniscus damage was significantly increased in those who had three or more finger joints with OA (1.40 [95% confidence interval (CI) 1.11-1.77]). The estimate remained similar in persons without evidence of radiographic OA in their knee (PR, 1.42 [95% CI 1.03-1.97]). The association was more robust for medial meniscus damage.Results suggest a common non-age related etiologic pathway for both radiographic hand OA and meniscus damage.
Project description:<h4>Objective</h4>To examine the cross-sectional associations between dietary magnesium (Mg) intake and radiographic knee osteoarthritis (OA), joint space narrowing (JSN), and osteophytes (OST) respectively.<h4>Methods</h4>A total of 1626 subjects were included in the study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Radiographic knee OA was defined as Kellgren-Lawrence (K-L) Grade 2 in at least one leg. JSN and OST were assessed individually according to the Osteoarthritis Research Society International (OARSI) atlas. A multivariable logistic analysis model was applied to test the various associations after adjusting for potentially confounding factors.<h4>Results</h4>The relative odds of radiographic knee OA were decreased by 0.53 times in the third quintile of Mg intake [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.28-1.01], 0.40 times in the fourth quintile (OR 0.40, 95% CI 0.17-0.94) and 0.34 times in the fifth quintile (OR 0.34, 95% CI 0.11-1.00) compared with those in the lowest quintile, while P for trend was 0.111. The relative odds of JSN were decreased by 0.49 times in the third quintile of Mg intake (OR 0.49, 95% CI 0.28-0.88) and 0.37 times in the fifth quintile (OR 0.37, 95% CI 0.14-0.98) compared with those in the lowest quintile, while P for trend was 0.088. There was no significant relationship between dietary Mg intake and the presence of OST.<h4>Conclusions</h4>The findings of this cross-sectional study indicate that Mg intake is inversely associated with radiographic knee OA and JSN. It supports potential role of Mg in the prevention of knee OA.<h4>Level of evidence</h4>LevelIII, cross-sectional study.