Comorbidities and health-related quality of life in Koreans with knee osteoarthritis: Data from the Korean National Health and Nutrition Examination Survey (KNHANES)

Cross-Sectional and Longitudinal Associations of Comorbidities with Knee Symptoms and Radiographic Abnormalities of Osteoarthritis

INTRODUCTION

This study aimed to investigate the associations of comorbidities with knee symptoms and radiographic abnormalities of osteoarthritis (OA).

METHODS

Participants were from the Osteoarthritis Initiative. Comorbidities were identified at baseline using the modified Charlson Comorbidity Index. For both knees, symptoms were assessed annually from baseline to 48 months using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores (rescaled range 0-100), and radiographic abnormalities using the Kellgren-Lawrence (KL, 0-4) grades. The presence of significant pain and functional disability was defined as a WOMAC score of ≥ 25 and ≥ 22, respectively, and radiographic OA (ROA) as KL ≥ 2. An increase of ≥ 9 in WOMAC scores and ≥ 1 in KL grades were defined as symptomatic and radiographic progression, respectively.

RESULTS

Of 3337 participants, 28% and 9% had one and ≥ 2 comorbidities, respectively. The number of comorbidities was associated with the presence of significant functional disability (odds ratios [ORs] 1.15; 1.46) and predicted the progression of both knee pain and functional disability (ORs 1.11; 1.51). For the type of comorbidities, non-OA musculoskeletal diseases were associated with the presence of ROA and significant functional disability (ORs 1.63; 1.82) and showed a trend to predict incident ROA (OR 1.84, 95% confidence interval 1.00-3.38 p = 0.051). Diabetes and kidney diseases were associated with symptomatic progression of OA (ORs 1.38; 2.72).

CONCLUSIONS

Having more comorbidities, especially diabetes and kidney diseases, is associated with symptomatic progression of knee OA. Moreover, non-OA musculoskeletal diseases may be associated with the presence and onset of ROA.

Osteoarthritis knee and modifiable cardiovascular risk factors: play in tandem

Objective

To know the frequency of modifiable cardiovascular risk factors in knee osteoarthritis patients.

Method

Cross sectional study was done at Department of Rheumatology Indus Medical College, Tando Mohammad Khan from March 25, 2022 to November 24, 2022. Total 246 Osteoarthritis of knee cases with (Kellgren-Lawrence grad-II and above) on x-ray, were selected after demographic details, blood pressure, body mass index and physical examination was done, 5ml of venous blood was drawn by phlebotomist, sent for fasting blood sugar, serum lipids analysis and Framingham 10years risk score was calculated afterward for each participant.

Results

In this study males (126) and females (120). Overall (78%) had risk factors, Patients having one CVD risk factor were (22.8%), two risk factors in (21.1%), three in (21.5%), four (9.8%) and five factors in (1.6%) while frequency of modifiable cardiovascular risk shows obesity (45.5%) hypertension (40.2%) intermediate to high risk of framingham score (40%) diabetes mellitus (25%), smoking (17%), high low density lipoproteins (8.1%). In males obesity(54.2%), hypertension (47.5% ) and (45.8%) were on medication, diabetes mellitus(31.7%), smoker(31%), high risk FRS(39.2%), K-L grade-IV(58.4%) and in females: obesity (42%), hypertension (43.7%) and (40.5%) were on medication, diabetes mellitus in (19%), smoking (4%), high risk FRS (13.5%), K-L Grade-4 (42%), significant association of diabetes mellitus, smoking, FRS and K-L grades with gender (p<0.05).

Conclusion

In OA knee there is high prevalence of modifiable cardiovascular risk factors and together these imposes a major health risk for future cardiac events and disability.

The relationship between experience of knee pain and physical activity participation: A scoping review of quantitative studies

Objectives

Physical activity (PA) in people with knee pain can help to relieve pain and prevent health problems. However, engaging in regular PA is challenging for them due to chronic musculoskeletal pain. An understanding of how the experience of knee pain affects PA is important to minimize the negative effects of knee pain on participation in PA among this population. We examined the quantitative evidence describing the relationship between the experience of knee pain and participation in PA.

Methods

We conducted a scoping review based on the PRISMA-ScR process across 27 items and Peters' methodological framework. Searches using keywords were performed in Medline, PsycINFO, CINAHL and Scopus.

Results

Nine studies were included in this review. While one study clearly showed that increased knee pain increased PA, four studies indicated that knee pain decreased PA among individuals with knee pain. One study revealed that increased knee pain decreased moderate PA, but no significant difference with light intensity PA. Three studies showed that knee pain had no impact on PA. Moreover, psychological factors (catastrophizing and pain-related activity interference) and certain activities of daily living were risk factors for insufficient PA among people with knee pain.

Conclusions

The limited quantitative evidence on the relationship between the experience of knee pain and PA participation highlights a gap in the knowledge base. The review findings found mixed results, with a negative, positive or no relationship between knee pain and levels of PA among individuals with knee pain. The findings also suggest that the relationship can be affected by psychological factors and different levels and types of PA. Therefore, practitioners should consider multi-component interventions which aim to increase PA levels of individuals with knee pain, after considering the above mediating factors.

The association between short-term, chronic localized and chronic widespread pain and risk for cardiovascular disease in the UK Biobank

AIMS

The interplay between pain of different chronicity and cardiovascular disease (CVD) is incompletely understood. We aimed to investigate the association between different levels of chronic or nonchronic pain and risk of CVD.

METHODS AND RESULTS

Participants in the UK Biobank who reported pain at baseline were divided into three groups according to pain duration and widespreadness. Participants reporting no pain were controls. Multivariable Cox regression was used to investigate the association between pain and incidence of myocardial infarction, heart failure, stroke, cardiovascular mortality, and composite CVD (defined as any of the before-mentioned cardiovascular events). Of 475 171 participants, 189 289 reported no pain, 87 830 reported short-term pain, 191 716 chronic localized pain, and 6336 chronic widespread pain (CWP). During a median of 7.0 years' follow-up, participants with chronic localized pain and CWP had, after adjustment for age, sex, established cardiovascular risk factors, physical activity, anxiety, depression, cancer, chronic inflammatory/painful disease, pain/anti-inflammatory medication, socioeconomic status, a significantly increased risk for composite CVD [hazard ratio (HR) 1.14, confidence interval (CI) 1.08-1.21, P < 0.001; and HR 1.48, CI 1.28-1.73, P < 0.001, respectively] compared with controls, with similar results when using the different specific CVDs as outcomes. Population attributable risk proportion for chronic pain as a risk factor for composite CVD was comparable with that of diabetes (8.6 vs. 7.3%, respectively).

CONCLUSION

Chronic pain is associated with an increased risk for myocardial infarction, stroke, heart failure, and cardiovascular death independent of established cardiovascular risk factors, socioeconomic factors, comorbidities and medication. Our study, the largest to date, confirms and extends our understanding of chronic pain as an underestimated cardiovascular risk factor with important public health implications.

Cross-sectional assessment of cardiovascular risk factors in patients with knee osteoarthritis

Background: Osteoarthritis (OA) and cardiovascular disease (CVD) are prevalent in India. However, there is dearth of literature among Indians studying the relationship between the two. This study was carried out to assess various cardiovascular (CV) risk factors in patients with knee OA with an objective to investigate their association, screening and management.  Methods: In total, 225 patients were included in this cross-sectional study. Participants were diagnosed with knee OA on the basis of the Kellgren and Lawrence (K-L) classification of their radiograph. Participants were also assessed for CV risk factors (age, body mass index, systolic blood pressure, diabetes mellitus, total cholesterol, high-density lipoprotein, smoking) with the help of the Joint British Society QRisk3 calculator (JBS3) a comprehensive risk score calculator as well as a screening tool, which produces three more variables, namely 10-years risk of developing CVD, physiological heart age and life expectancy. Chi Square, Fishers exact test and one-way ANOVA tests were used to compare the categorical and quantitative variables, respectively. Pearson's correlation coefficient was used to assess the relationship between CV risk factors and knee OA. Multiple regression analysis was done to adjust the multiple con-founders and determine their significance. Results: Patients with severe knee OA had a statistically significantly higher prevalence of CV risk factors (p<0.05). Grade 4 knee OA patients were found to have a mean JBS3 risk of 38%, heart age of 82 years and life expectancy of 77 years as compared to grade 2 patients who had a mean JBS3 risk of 11%, heart age of 63 years and life expectancy of 82 years.  Conclusions: Our study concluded that there is a strong positive correlation between knee OA and CVD, with CV risk score being directly proportional to the severity of OA.

Understanding health problems in people with extremely low health-related quality of life in Korea

Little is known about patients reporting extremely poor health-related quality of life (HRQoL). This study targeted population with inferior HRQoL and examined their problems experienced with HRQoL dimensions, and impacts of different morbidities on these problems. Data were obtained from a population-based survey in Korea. HRQoL was measured by EQ-5D questionnaire and low-HRQoL population was defined as individuals whose EQ-5D utility score was among the lowest 5% of total survey population. Logistic regression models were used to evaluate the impact of fifteen morbidities on HRQoL dimensions. Of 2976 low-HRQoL participants, females and low socioeconomic individuals were predominant. They experienced significantly more problems in all dimensions, with pain/discomfort, and mobility as the most frequently reported problems. Problems in HRQoL dimensions diverged according to diseases. Individuals with arthritis experienced more difficulties with mobility (aOR 2.62, 95% CI 1.77–3.87) and pain/discomfort (aOR 2.86, 95% CI 1.78–4.60). Stroke patients experienced more problems in self-care (aOR 2.24, 95% CI 1.59–3.15) and usual activities (aOR 1.87, 95% CI 1.11–3.14). Having two or more diseases was associated with worse outcomes in usual activities and increased risk of depression. Thus, efforts to improve status of low-HRQoL should be customized to fulfil unmet needs corresponding to various diseases, and depression prevention is needed for those with multimorbidity status.

Comorbidities and Health-Related Quality of Life in Subjects with Spine Osteoarthritis at 50 Years of Age or Older: Data from the Korea National Health and Nutrition Examination Survey

Background and Objective: This study assessed comorbidities and health-related quality of life (HRQOL) in subjects with lumbar spine osteoarthritis (OA) in the Korean population. Materials and Methods: We analyzed 3256 subjects who were 50 years or older and underwent plain radiography of the lumbar spine as part of the Korea National Health and Nutrition Examination Survey (KNHANES) 2012. Radiographic assessment was based on Kellgren–Lawrence (K-L) grade ranging from 0 to 2, with K-L grade 2 defined as lumbar spine OA. HRQOL was assessed by EuroQol-5 dimensions (EQ-5D), which include the EQ-5D index and visual analogue scale (EQ-VAS) measurements. Results: Comorbidities such as hypertension, myocardial infarction, angina, cerebral infarction, and diabetes mellitus were more frequent in spine OA than in controls, while dyslipidemia was less common. Subjects with spine OA had higher mean number of comorbid conditions than controls (1.40 (SE 0.05) vs. 1.20 (SE 0.03), p = 0.001). Subjects with spine OA had much lower EQ-5D index than controls (p < 0.001) but not lower EQ-VAS score. Multivariate binary logistic analysis showed that hypertension and colon cancer were associated with spine OA compared to controls (OR 1.219, 95% CI 1.020–1.456, p = 0.030 and OR 0.200, 95% CI 0.079–0.505, p = 0.001, respectively) after adjustment for confounding factors. Lower EQ-5D index was related to spine OA (95% CI 0.256, 95% CI 0.110–0.595, p = 0.002) but not EQ-VAS score. Conclusion: In this study, we found that comorbidities such as hypertension and colon cancer as well as lower HRQOL were associated with spine OA.

Gender-Specific Association of Serum Uric Acid and Pulmonary Function: Data from the Korea National Health and Nutrition Examination Survey

Background and Objectives: Hyperuricemia is associated with several comorbidities. The association between uric acid (UA) and pulmonary function is still a controversial issue. This study evaluated the gender-specific association of serum UA and pulmonary function. Materials and Methods: A total of 3177 (weighted n = 19,770,902) participants aged 40 years or older were selected from the 2016 Korean National Health and Nutrition Examination Survey and included. Results: Female participants with hyperuricemia were older than participants with normouricemia. Body mass index (BMI), mean arterial pressure (MAP), hemoglobin A1c (HbA1c), and estimated glomerular filtration rate (eGFR) were significantly associated with UA levels in both males and females. Hyperuricemia and increase in UA quartile were significantly associated with decreased forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in females after adjustment for age, income, region, education, marital status, alcohol consumption, smoking, BMI, MAP, HbA1c, and eGFR. There was no significant association between UA levels and lung function in males. After additional adjustment for respiratory disease including pulmonary tuberculosis, asthma, and lung cancer, the association between hyperuricemia and decreased FEV1 and FVC in females was revealed. Conclusions: Hyperuricemia was associated with decreased FVE1 and FVC in the female general population.

Prevalence of Knee Osteoarthritis and Health-Related Quality of Life in Stroke Patients over 60 Years Old: A Cross-Sectional Study Using Korean National Health and Nutrition Examination Survey V

Background

This study investigated the prevalence of knee osteoarthritis among stroke survivors aged over 60 years and analyzed the association between knee osteoarthritis and health-related quality of life (HRQOL) in stroke survivors.

Methods

We analyzed data of 287 participants who had experienced a stroke (stroke group) from the 2010–2012 Korean National Health and Nutrition Examination Survey. Among the participants, 65 stroke survivors also had knee osteoarthritis. We used the European Quality of Life-5 Dimensions (EQ-5D) questionnaire to compare the differences in HRQOL according to the presence or absence of knee osteoarthritis in the stroke group. Multiple regression analysis was performed to determine associated factors affecting HRQOL in the stroke group.

Results

The prevalence of knee osteoarthritis was 21% in the stroke group. The EQ-5D index score was significantly lower in patients in the stroke group with knee osteoarthritis than in those without knee osteoarthritis (adjusted mean±standard error [SE], 0.680±0.011 for stroke with knee osteoarthritis and 0.817±0.003 stroke without knee osteoarthritis; p<0.0001). Knee osteoarthritis, age, income level, education level, smoking, walking days, diabetes, and cardiovascular disease significantly influenced HRQOL in the stroke group.

Conclusion

The study results confirmed that the prevalence of knee osteoarthritis was 21% in the stroke group and that HRQOL was significantly lower among patients in the stroke group with knee osteoarthritis. These findings suggest the importance of active management of knee osteoarthritis in stroke survivors for HRQOL.

Cross-sectional assessment of cardiovascular risk factors in patients with knee osteoarthritis

Background: Osteoarthritis (OA) and cardiovascular disease (CVD) are prevalent in India. However, there is dearth of literature among Indians studying the relationship between the two. This study was carried out to assess various cardiovascular (CV) risk factors in patients with knee OA with an objective to investigate their association, screening and management.  Methods: In total, 225 patients were included in this cross-sectional study. Participants were diagnosed with knee OA on the basis of the Kellgren and Lawrence (K-L) classification of their radiograph. Participants were also assessed for CV risk factors (age, body mass index, systolic blood pressure, diabetes mellitus, total cholesterol, high-density lipoprotein, smoking) with the help of the Joint British Society QRisk3 calculator (JBS3) a comprehensive risk score calculator as well as a screening tool, which produces three more variables, namely 10-years risk of developing CVD, physiological heart age and life expectancy. Chi Square, Fishers exact test and one-way ANOVA tests were used to compare the categorical and quantitative variables, respectively. Pearson's correlation coefficient was used to assess the relationship between CV risk factors and knee OA. Multiple regression analysis was done to adjust the multiple con-founders and determine their significance. Results: Patients with severe knee OA had a statistically significantly higher prevalence of CV risk factors (p<0.05). Grade 4 knee OA patients were found to have a mean JBS3 risk of 38%, heart age of 82 years and life expectancy of 77 years as compared to grade 2 patients who had a mean JBS3 risk of 11%, heart age of 63 years and life expectancy of 82 years.  Conclusions: Our study concluded that there is a strong positive correlation between knee OA and CVD, with CV risk score being directly proportional to the severity of OA.

Barriers to and Facilitators of Physical Activity among Korean Female Adults with Knee Osteoarthritis and Comorbidity: A Qualitative Study

When knee osteoarthritis is combined with comorbidity, it is associated with limited physical activity. This study aimed to identify barriers to and facilitators of physical activity among Korean female adults with knee osteoarthritis and comorbidity, such as hypertension, diabetes, and dyslipidemia. A qualitative content analysis study was conducted. Ten female knee osteoarthritis participants with comorbidity were recruited at an orthopedic outpatient center in South Korea. Data were collected using in-depth interviews and were analyzed using a conventional content analysis method. Ten participants with a mean age of 70.7 years participated in this study. Four categories of barriers and three of facilitators were identified. Barriers to physical activity were physical hardships, lack of motivation, environmental restrictions, and lack of knowledge. Categories of facilitators were pain management, self-control in physical activity, and understanding the importance of physical activity. Participants did not express any social or environmental facilitators of physical exercise. Healthcare professionals should include social support and environmental facilities to achieve medical and institutional compliance. Understanding female adults with knee osteoarthritis and comorbidity would support provision of appropriately tailored interventions that account for the characteristics of the comorbidity.

Health-related quality of life and its influencing factors in Chinese with knee osteoarthritis

PURPOSE

To evaluate the health-related quality of life (HRQoL) of knee osteoarthritis (KOA) patients in China, compare their HRQoL with norm population, and examine the associations between the potential influencing factors and HRQoL.

METHODS

A cross-sectional study was conducted in 912 KOA patients from 4 provinces between March and November 2017. All participants were diagnosed according to the National Institute for Health and Care Excellence (NICE)'s criterion or the Chinese Medical Association (CMA)'s criterion. Recruited patients were surveyed for HRQoL using the 12-item Short Form (SF-12) and sociodemographic, disease-related factors. We assessed the associations between potential influencing factors and HRQoL using multiple linear regression models.

RESULTS

Among the KOA patients, the mean physical component summary (PCS) of HRQoL was 40.91 ± 11.62, lower than norm (P < 0.001). And the mean mental component summary (MCS) was 50.25 ± 11.99, similar to the norm. Patients who were older (β = - 0.155, P = 0.001), women (β =  - 4.589, P < 0.001), had ever been treated (β =  - 2.426, P = 0.006), had longer course of KOA (β =  - 0.164, P = 0.012), and were in early stage (β =  - 2.968, P = 0.001) or progressive/late stage (β =  - 7.636, P < 0.001) showed lower scores of PCS. Patients who lived in Hunan (β = 4.988, P < 0.001) and had education levels of junior high school (β = 3.134, P = 0.012) or senior high school and above (β = 3.050, P = 0.010) had better mental status. Those suffered from non-knee pains (β =  - 2.308, P = 0.027) and with progressive or late KOA (β =  - 4.690, P = 0.016) had lower MCS scores.

CONCLUSION

KOA patients had worse physical condition. The mental and physical health of patients were affected by different factors. Targeted management measures should be taken to improve their HRQoL.

A Single-Center Retrospective Chart Review to Determine Whether the Presence of Comorbidities Affects Colon Cancer Screenings in African Americans

Colon cancer is the third leading cause of cancer-related death in African Americans. Although the rates of colon screenings have risen, African Americans remain to be underscreened, and are more likely to present with advanced lesions. This population has a higher prevalence of inflammatory comorbidities, and their effects on screenings have not been fully explored. Along with higher rates of comorbidities, the Southeastern United States is one region for the highest rates of colorectal cancer. The purpose of this study was to determine whether people with comorbidities were more likely to have a screening colonoscopy. Convenience sampling was used to procure 408 patients. The median age was 55 years, and the majority were females (52.2%), who were obese (29.2%), and nonsmokers (52.2%). The most common comorbidity was hypertension (70.3%), followed by osteoarthritis (39%), and diabetes (25.5%). There is a well-documented trend between certain inflammatory comorbidities and higher death rates in patients with colorectal cancer. Clarifying the relationship between comorbidities and cancer starts with screening as many patients as possible. Therefore, interventions that support increasing the number of colorectal cancer screenings are imperative in order to improve morbidity and mortality in this despaired population.

Synergistic effects of hip/knee osteoarthritis and comorbidities on mobility and self-care limitations among older adults: Cross-sectional analysis of the Oxford pain, Activity and Lifestyle study

OBJECTIVE

To estimate synergistic effects of hip/knee osteoarthritis (OA) and comorbidities on mobility or self-care limitations among older adults.

METHODS

We used baseline, cross-sectional data from the Oxford Pain, Activity and Lifestyle (OPAL) study. Participants were community-dwelling adults aged 65 years or older who completed a postal questionnaire. Participants reported demographic information, hip/knee OA, comorbidities and mobility and self-care limitations. We used modified Poisson regression models to estimate the independent and combined relative risks (RR) of mobility or self-care limitations, the relative excess risk due to interaction (RERI) between hip/knee OA and comorbidities, attributable proportion of the risk due to the interaction and the ratio of the combined effect and the sum of the individual effects, known as the synergy index.

RESULTS

Of the 4,972 participants included, 1,532 (30.8%) had hip/knee OA, and of them 42.9% reported mobility limitations and 8.4% reported self-care limitations. Synergistic effects impacting self-care limitations were observed between hip/knee OA and anxiety (RR: 3.09, 95% Confidence Interval (CI): 2.00 to 4.78; RERI: 0.93, 95% CI: 0.01 to 1.90), and between hip/knee OA and depressive symptoms (RR: 2.71, 95% CI: 1.75 to 4.20; RERI: 0.58, 95% CI: 0.03 to 1.48). The portion of the total RR attributable to this synergism was 30% and 22% respectively.

CONCLUSIONS

This study demonstrates that synergism between hip/knee OA and anxiety or depressive symptoms contribute to self-care limitations. These findings highlight the importance of assessing and addressing anxiety or depressive symptoms when managing older adults with hip/knee OA to minimize self-care limitations.

Co-occurrence of Chronic Musculoskeletal Pain and Cardiovascular Diseases: A Systematic Review with Meta-analysis

Objective

To determine the magnitude of the association between cardiovascular disease and chronic musculoskeletal pain.

Design

Systematic review with meta-analysis.

Methods

A comprehensive search was performed in five electronic databases. Population-based studies reporting the prevalence of cardiovascular diseases in adults stratified by chronic musculoskeletal pain status were considered eligible. Two independent reviewers performed the screening of the records following the inclusion criteria, extracted data, and evaluated the risk of bias of the included studies using an assessment tool of risk of bias for observational studies. In addition, we assessed the overall quality of evidence using an adaptation of the GRADE approach for prognosis.

Results

Twenty studies were included in this review. There was high-quality evidence that people with chronic musculoskeletal pain are 1.91 times more likely to report having a cardiovascular disease compared with those without chronic musculoskeletal pain (risk ratio = 1.91, 95% confidence interval = 1.64–2.21).

Conclusions

Our findings demonstrated associations between chronic musculoskeletal pain and any cardiovascular diseases. Future studies are still warranted to better understand the association between chronic musculoskeletal pain and the specific types of cardiovascular diseases.

Relationship between oxidative balance score and quality of life in patients with osteoarthritis: Data from the Korea National Health and Nutrition Examination Survey (2014-2015)

Osteoarthritis (OA) has a multifactorial etiology that includes oxidative stress. Oxidative balance score (OBS) is a well-known indicator of oxidative stress. However, the association between OBS and OA has not been assessed. Thus, this study aimed to investigate the associations of OBS with OA and quality of life (QOL) in patients with OA.By using data from the Korea National Health and Nutrition Examination Survey VI, patients previously diagnosed and/or treated by a physician were considered to have OA regardless of the affected joints. The control group was defined as participants without any form of chronic arthritis. OBS was calculated by combining 10 pro-oxidant and antioxidant factors through a baseline nutritional and lifestyle assessment. Higher OBS scores indicated a predominance of antioxidant exposure. Multivariable logistic regression was used to estimate the adjusted odds ratios (ORs) for OA, and the EuroQoL five-dimensional questionnaire (EQ5D) was used in patients with OA after adjusting for demographic factors and comorbidities.Among the 14,930 participants, 296 patients with OA, and 1,309 controls were included in the analysis. In the age- and sex-adjusted model, the OR of the total OBS for OA was significant. In the full model adjusted for age, sex, education, income, and comorbidities, the total OBS for OA was not significant. Only the non-dietary pro-oxidant OBS had a significant inverse association with OA. The patients with OA who had a high EQ5D score had a higher total OBS than those with a low EQ5D score. The OR of the total OBS for a high EQ5D score was 1.14 in the multivariable logistic regression model. As we analyzed the OBS as a categorical variable (reference = Q1), the ORs of the Q2, Q3, and Q4 (highest) total OBS were 1.43, 2.71, and 2.22, respectively.In the fully adjusted model, the total OBS was not associated with OA. However, a positive association was observed between the total OBS and QOL in the patients with OA, indicating that antioxidative status was associated with better QOL in patients with OA.

Factors related to quality of life among middle-aged and older korean adults in 2006 and 2014: A nationally representative study

Factors related to quality of life (QoL) were investigated using data from middle-aged and older Korean respondents to the 2006 and 2014 Korean Longitudinal Study of Ageing. Respondents' QoL score in 2014 (6.03 ± 1.69) was lower than in 2006 (6.20 ± 2.12). All socio-demographic and health-related variables seemed to influence QoL in 2006 (R² = 0.238) and 2014 (R² = 0.234). Four factors significantly associated with QoL in both years were health, household income, depression, and regular exercise. Rural and mid-sized city dwellers were more likely to have a better QoL than residents of metropolitan areas; residential area had a greater influence on QoL in 2014.