Knee Osteoarthritis
Conditions
Brief 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.
Interventions
OTHERDiet
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).
OTHERExercise
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.
Sponsors
Baylor University
Curves International
Texas A&M University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
\- General entrance criteria included being a female with physician diagnosed OA between the ages of 18-70 years with a body mass index (BMI) \> 27 kg/m2 and no recent participation in a diet or exercise program.
Exclusion criteria
\- Subjects were not allowed to participate in this study if they: 1.) were pregnant, became pregnant, or had a desire for pregnancy; 2.) had any metabolic disorder including known electrolyte abnormalities, heart disease, arrhythmias, diabetes, thyroid disease, or hypogonadism; 3.) had a history of hypertension, hepatorenal, musculoskeletal, autoimmune, or neurological disease; were taking thyroid, hyperlipidemic, hypoglycemic, anti-hypertensive, or androgenic medications; 4.) had taken ergogenic levels of nutritional supplements that may affect muscle mass (e.g., creatine, HMB), anabolic/catabolic hormone levels (e.g., DHEA), or weight loss supplements (e.g., thermogenics) within three months prior to the start of the study; 5.) were ingesting any anti-inflammatory products two weeks before the start of the study or additional products during the study; 6.) reported any unusual adverse events associated with this study in which the supervising physician recommended removal from the study; 7.) had significant injury or surgery to the lower extremity or spine within the last six months; 8.) did not indicate a minimal amount of perceived pain and physical function limitation on inventories used in the study; 9.) had severe arthritis that required surgery and greatly limited functionality (inability to perform lunge); or, 10.) had arthritis that required the current use of physiotherapy modalities.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Functional Capacity | 14 weeks | Perceptions of pain, knee flexibility, knee strength and endurance, upper body strength and endurance, peak aerobic capacity, and functional assessmentof balance using the sit to stand, step up and over, and forward lunge tests. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Weight loss and body composition | 14 weeks | All participants were tested for changes in energy intake; anthropometrics; body composition; and resting energy expenditure to assess magnitude of weight loss in response to a higher carbohydrate and higher protein diet. |
| Blood and Hormones | 14 Weeks | General whole blood and serum clinical chemistries (cholesterol, triglycerides, glucose, blood urea nitrogen, creatinine, uric acid, muscle and liver enzymes) and hormones (C-Reactive Protein, IL-6, TNF-alpha, cortisol, insulin, homeostasis model of insulin sensitivity, and leptin). |
| Psychosocial | 14 Weeks | SF-36 quality of life indices |
Countries
United States
Outcome results
None listed