Journal of Rehabilitation Medicine 51-6 | Page 70

J Rehabil Med 2019; 51: 464–470 ORIGINAL REPORT ASSOCIATION BETWEEN METABOLIC SYNDROME AND KNEE OSTEOARTHRITIS: A CROSS-SECTIONAL NATIONWIDE SURVEY STUDY Byung Joo LEE, MD 1 , Seoyon YANG, MD, PhD 2 , Sara KWON, MD 2 , Kyoung Hyo CHOI, MD, PhD 2 and Won KIM, MD 2 From the 1 Department of Rehabilitation Medicine, Daegu Fatima Hospital, 2 Department of Rehabilitation Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea Objective: To investigate the association of metabo- lic syndrome with the development of knee osteo- arthritis. Design: Cross-sectional nationwide survey study. Subjects: Data obtained from the 2010–2012 Korea National Health and Nutrition Examination Survey. Methods: Subjects aged 50 years or older were in- cluded. Knee osteoarthritis (≥grade 2 Kellgren- Lawrence) and severe knee osteoarthritis (≥grade 3 Kellgren-Lawrence) were evaluated based on ra- diological findings. Medical information and demo- graphic data were obtained from survey records. Multivariate regression analysis was performed to investigate the relationship between knee osteo- arthritis and metabolic syndrome, and the number of metabolic syndrome components for dose-response relationship evaluation. Analyses were adjusted by age group (model 1) or by age group, education, smoking, alcohol consumption, and physical activity (model 2). Results: A total of 8,491 subjects (3,684 men and 4,807 women) were included in the study. In wo- men, metabolic syndrome increased the risk of knee osteoarthritis (odds ratio (OR) = 1.644, p  < 0.001; and OR = 1.608, p  < 0.001; respectively; for models 1 and 2) and severe knee osteoarthritis (OR = 1.593, p  < 0.001; and OR = 1.559, p  < 0.001; respectively; for models 1 and 2). However, in men, knee osteo- arthritis and severe knee osteoarthritis were not as- sociated with metabolic syndrome. As the number of metabolic syndrome components increased, knee osteoarthritis and severe knee osteoarthritis gene- rally increased in women, but not in men. Conclusion: Metabolic syndrome affects the deve- lopment of knee osteoarthritis and severe knee os- teoarthritis in women. In addition, dose-response relationships were observed between metabolic syndrome components and knee osteoarthritis in women, but not in men. Key words: metabolic syndrome; osteoarthritis; abdominal obesity; hypertension; hyperglycaemia; hyperlipidaemia. Accepted May 3, 2019; Epub ahead of print May 16, 2019 J Rehabil Med 2019; 51: 464–470 Correspondence address: Won Kim, Department of Rehabilitation Med- icine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. E-mail: [email protected] K nee osteoarthritis (OA) is a common musculos- keletal disorder in old age. It presents with joint LAY ABSTRACT Knee osteoarthritis is a common disorder in old age and is known to be associated with various medical condi- tions. Metabolic syndrome is a cluster of conditions in- cluding hypertension, dyslipidemia, abdominal obesity, and insulin resistance, with a rapidly increasing preva- lence. The purpose of our study was to investigate the effect of metabolic syndrome on development of knee osteoarthritis. The result showed that metabolic syn- drome affects the development of knee osteoarthritis and severe knee osteoarthritis in women. Additionally, the number of metabolic syndrome components showed additive effect on development of knee osteoarthritis. However, these relationships were not definite in men. Through our study, we were able to connect the impact of metabolic syndrome on knee osteoarthritis. Careful and thorough examination of knee osteoarthritis should be considered in patients complaining of knee pain in case of metabolic syndrome patient. Also, treatment of the components of metabolic syndrome should be em­ phasized, such case. pain and stiffness, and consequently reduces individual function and quality of life (1). Knee OA affects over 250 million people globally (2). It is expected that this number will increase rapidly in the future, as longer life expectancy leads to a growing elderly population (3). Mechanical stress has been considered the primary cause of the development of knee OA, and higher pre- valence in old age and obesity suggest a relationship between mechanical stress and knee OA. Sex is another risk factor; women are at a higher risk than men (4). However, many researchers have recently suggested that other factors, such as genetic, neuroendocrine, and metabolic factors, may also play a role in the pathop- hysiological mechanism of knee OA (5). Metabolic syndrome refers to a cluster of conditions, including hypertension, dyslipidaemia, abdominal obe- sity, and insulin resistance, with a rapidly increasing prevalence (6). In the presence of metabolic syndrome, general or local inflammatory reactions increase, and advanced glycation end-products accumulate or local ischaemia develops (7). These may contribute to the development of OA. Researchers have studied the association of the metabolic effects of diabetes and obesity with the development of OA. However, the results have been inconsistent. In addition, most studies only investigated the relationship between individual metabolic conditions and OA (8–11). The relationship This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm doi: 10.2340/16501977-2561 Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977