Effects of Glucosamine and Chondroitin Supplementation in Women With Knee Osteoarthritis Participating in an Exercise and Weight Loss Program
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee; Weight Loss
Study type: Interventional
Phase: Phase 4

Summary: 
      Background: Exercise, weight loss, and dietary supplementation of glucosamine and chondroitin
      (GC) have been reported to improve functional capacity in individuals with knee
      osteoarthritis (OA). The purpose of this study was 1.) to determine whether women with knee
      OA who follow a higher protein diet observe more favorable changes in body composition and/or
      markers of health compared to those following a standard higher carbohydrate-based diet; and,
      2.) to determine whether dietary supplementation of glucosamine and chondroitin during a
      weight loss and fitness program lessens symptoms of pain, improves functional capacity,
      and/or promotes greater health benefits in women with knee OA. It was hypothesized that both
      groups would experience beneficial changes in body mass, body composition, and markers of
      health. However, greater benefits would be observed in those following a higher protein diet
      while supplementing the diet with glucosamine and chondroitin.
    

Detailed description: 
      The study was conducted as a randomized, double-blind, placebo-controlled clinical trial in a
      university research setting. Participants with physician diagnosed OA participated in a
      14-week fitness and weight loss program that consisted of moderately hypo-energetic higher
      protein or higher carbohydrate diets. Participants were also randomly assigned to ingest in a
      double-blind and randomized manner either a placebo or a commercially available dietary
      supplement containing glucosamine and chondroitin. Outcome measures were assessed at 0, 10,
      and 14 weeks of training, dieting, and supplementation.
    

Intervention name(s): Diet; Exercise
Intervention type(s): Other; Other
Intervention description(s): Participants followed isoenergetic low fat diets with higher protein (HP) or higher carbohydrate (HC) macronutrient content. Participants consumed 1,200 kcals/d for 1-week (Phase I) and 1,600 kcals/d for 9-weeks (Phase II) during a 10-week weight loss period. Participants in the HC diet consumed a diet containing 55% carbohydrate, 15% protein, and 30% fat. Subjects in the HP group consumed a diet containing 7% carbohydrate, 63% protein, and 30% fat during Phase I of the diet and 15% carbohydrate, 55% protein, and 30% fat during Phase II of the diet. The final 4-weeks of the diet (Phase III) served as a weight maintenance period in which participants consumed 2,600 kcals•d-1 consisting of 55% carbohydrate, 15% protein, and 30% fat and were instructed to follow their respective Phase I diet (1,200 kcals/d) for 2-days only if they gained 1.35 kg (3 lbs).; All subjects participated in a supervised exercise program three days per week for 14-weeks. Each circuit-style workout consisted of 14 exercises (e.g. elbow flexion/extension, knee flexion/extension, shoulder press/lat pull, hip abductor/adductor, chest press/seated row, horizontal leg press, squat, abdominal crunch/back extension, pec deck, oblique, shoulder shrug/dip, hip extension, side bends and stepping). Participants performed as many repetitions in a 30-s time period. In a continuous, interval fashion, participants performed floor-based callisthenic (e.g. running/skipping in place, arm circles, etc.) exercises on recovery pads for a 30-s time period after each resistance exercise in an effort to maintain a consistent exercise heart rate that corresponded to 60% to 80% of their maximum heart rate.
Other intervention name(s): Curves® weight loss program (Curves International, Waco, TX).; Curves exercise program.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Supportive Care