مقاله انگلیسی رایگان در مورد مطالعه پیشگیری از آرتروز – الزویر 2024

Abstract

Background
Osteoarthritis (OA), the leading cause of disability among adults, has no cure and is associated with significant comorbidities. The premise of this randomized clinical trial is that, in a population at risk, a 48-month program of dietary weight loss and exercise will result in less incident structural knee OA compared to control.

Methods/design
The Osteoarthritis Prevention Study (TOPS) is a Phase III, assessor-blinded, 48-month, parallel 2 arm, multicenter randomized clinical trial designed to reduce the incidence of structural knee OA. The study objective is to assess the effects of a dietary weight loss, exercise, and weight-loss maintenance program in preventing the development of structural knee OA in females at risk for the disease. TOPS will recruit 1230 ambulatory, community dwelling females with obesity (Body Mass Index (BMI) ​≥ ​30 ​kg/m2) and aged ≥50 years with no radiographic (Kellgren-Lawrence grade ≤1) and no magnetic resonance imaging (MRI) evidence of OA in the eligible knee, with no or infrequent knee pain. Incident structural knee OA (defined as tibiofemoral and/or patellofemoral OA on MRI) assessed at 48-months from intervention initiation using the MRI Osteoarthritis Knee Score (MOAKS) is the primary outcome. Secondary outcomes include knee pain, 6-min walk distance, health-related quality of life, knee joint loading during gait, inflammatory biomarkers, and self-efficacy. Cost effectiveness and budgetary impact analyses will determine the value and affordability of this intervention.

Discussion
This study will assess the efficacy and cost effectiveness of a dietary weight loss, exercise, and weight-loss maintenance program designed to reduce incident knee OA.

Backgrounds

Osteoarthritis (OA), the leading cause of disability among adults, has no cure and is associated with significant comorbidities [1]. Its increased prevalence and severity make it burdensome for people afflicted with the disease, and for health care organizations intended to administer care [2]. Obesity and OA were first linked in 1945 and this relationship has since been verified repeatedly [[3], [4], [5], [6]]. Obesity is a major risk factor associated with knee pain; people with obesity were 2.7 times more likely to have knee OA than adults without obesity [7].

Our mechanistic model, influenced by the seminal work of Griffin and Guilak [8], supports the premise that dietary weight loss and exercise may reduce knee joint loads, lower inflammation, and increase self-efficacy resulting in a lower incidence of structural knee OA (Fig. 1). Previous work showed that weight loss decreased knee joint loads such that every pound lost was associated with a 4-pound reduction in knee compressive forces while walking. The cumulative effect of this load reduction, over thousands of steps per day, reduces microdamage to the subchondral plate and calcified cartilage [9]. These areas are close to the overlying articular cartilage and likely protect articular cartilage integrity (Fig. 1).

Discussion

Implementing a randomized clinical trial designed to prevent incident knee OA presents numerous challenges. OA disease status and severity are defined structurally via x-ray [36] or MRI [19] and clinically using a combination of symptoms reported by the patient and derived from a physical exam [66]. The primary outcome measure for TOPS is structural knee OA using MRI, due to its superior sensitivity and granularity compared to radiographic assessments. In addition, the use of radiographic assessments as the primary outcome measure to determine the presence or absence of incident knee OA would have increased the sample size by 478 participants (39 ​%), requiring additional clinical centers and greater costs to test the hypothesis effectively.

Losing weight and preventing weight regain are difficult [67]. Biological changes fight attempts to maintain weight loss; the body acts in starvation mode increasing feelings of hunger, satiety is suppressed, metabolic rate slows, all in an attempt to defend higher body weights [68]. Psychosocial obstacles include decreased self-efficacy, increased chronic perceived psychosocial stress, and using food for comfort; environmental obstacles include large food portions and food availability [69]. Our previous work provides encouragement that most of the weight-loss attained by the TOPS diet and exercise group can be retained long-term with implementation of the weight-loss maintenance program. In a subsample of the IDEA cohort (N ​= ​94), the diet-only group retained 5.8 ​kg (65 ​%) of an 8.9 ​kg weight loss 3.5 years following completion of the 18-month diet intervention [70]. Maintenance of this clinically important weight-loss occurred without any post-intervention interaction with the study staff.