Body composition is more closely related to the development of knee osteoarthritis in women than men: A cross-sectional study using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1, 2)

Abstract

Purpose: Aging, trauma and obesity are the 3 main risk factors for knee, hip and hand osteoarthritis (OA). It is noteworthy that risk factors for shoulder OA (SOA) have been much less studied. SOA is divided into 2 anatomical subtypes: i) primary SOA (i.e., centered SOA) and ii) rotator cuff-related OA (i.e., non-centered SOA). We hypothesized that metabolic factors are preferentially associated with the primary SOA than the mechanical-induced rotator cuff-related SOA. Methods: This 2004e2012 retrospective multicentric study included patients with SOA at the time of joint surgery from 1 rheumatology and 2 orthopedic departments specialized in upper limb surgery. Clinical characteristics, especially hypertension, dyslipidemia, obesity (defined as body mass index >30), type 2 diabetes mellitus, current/past smoking, cardiovascular diseases and dysthyroidism were collected using medical files and phone calls to the patients for missing data. Primary SOA and rotator cuff-related SOA were defined by rheumatologists or surgeons using the standard radiographs. Exclusion criteria were history of a high-energy trauma on the shoulder, chronic inflammatory arthritis, avascular necrosis of the humeral head and age below 30 years-old. We first compared primary SOA and rotator cuff-related SOA using the chi-2 or Student t-test for all characteristics. Then a multivariate analysis using logistic regression was performed to determine specific factors associated with primary SOA. Results: We included 147 patients (mean ± SD age 75.8 ±10 years-old) including 101 women (68.7%). Centered SOA involved 99 patients and the other 48 had non-centered SOA. The comparison between the 2 groups indicated that centered SOA patients were older (primary SOA versus rotator cuff arthropathy: 77.5 ±9 vs 72.4 ±11 years-old; p¼0.004) and had more dysthyroidism (15% vs 4%; p¼0.05) without difference in each cardio-metabolic disturbance (body pass indexI: 27.2 ±5.1 vs 27.3 ±4.5; type 2 diabetes: 13% vs 15%; hypertension: 64% vs 66%; dyslipidemia: 36% vs 31% p¼non-significant) or in their accumulation between the 2 groups. Multivariate analysis indicated that older age was independently associated with primary SOA (odds ratio 95% confidence interval): 1.06 (1.02e1.1) p¼0.004), while cardiovascular event diseases was less associated with this subtype (OR (95%IC): 0.27 (0.089e0.824); p¼0.02). Dysthyroidism tended to be also associated with primary SOA (OR (95% IC): 3.47 (0.67e18.9); p¼0.14). Conclusions: Conversely to what expected, metabolic disturbances were not more prevalent in the primary SOA compared to the rotator cuff-related SOA. Surprisingly, whereas the primary OA population was older, CV diseases were more frequent in the rotator cuff-related SOA.