The purpose of the current exploratory clinical trial is to determine the effect of oral ingestion of metformin (OIM) in non-diabetic patients with chronic Achilles tendon pain. The trial has two aims; 1) to assess the effects of OIM treatment on tendon pain, and 2) to determine the effects of OIM capsules on tendon healing and repair. Twenty participants will be treated with metformin capsules for 16 weeks combined with a home exercise program. A comparison group of 20 participants will be treated with placebo tablets along with home exercise program.
This is a blinded and randomized controlled trial that focuses on the treatment effects of metformin (Met) on chronic tendon pain, healing, and repair in midportion Achilles tendinopathy. We will include a total 40 patients randomly divided into two equal groups: Group 1: Home Exercise Program + Placebo as a control group Group 2: Home Exercise Program + Oral Ingestion of Metformin Patients in group 1 will receive placebo capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. Patients in group 2 will receive metformin capsules,1 capsule (500 mg) daily for week one, 2 capsules (1,000 mg) daily for week two, 3 capsules daily for week 3 (1,500 mg), and 4 capsules daily (2,000 mg) for weeks 4-16. All patients will participate in a home exercise program through MedBridge, a HIPAA-compliant participant portal currently used by physical therapists at University of Pittsburgh Medical Center. There are 3 visits for this study. Visits include a Screening/Baseline visit, week 4 and week 16 visit. During each visit, participants will answer questions, complete functional testing, and undergo an ultrasound of the Achilles Tendon.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
40
University of Pittsburgh
Pittsburgh, Pennsylvania, United States
RECRUITINGChange in Victorian Institute of Sport Assessment - Achilles (VISA-A) Score
The VISA-A is a self-administered questionnaire that asks about Achilles tendon pain, function, and activity. Scores range from 0 to 100 with a low score indicating more severe pain.
Time frame: baseline, 4 weeks, 16 weeks
Change in VAS score
The VAS is a self-administered questionnaire that asks about pain. Scores range from 0 to 10 with a high score indicating more severe pain.
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon thickness
Images of the Achilles tendon in long axis will be acquired using B-mode ultrasound imaging. Maximum Achilles tendon thickness (mm) will be measured by a blinded investigator.
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon cross-sectional area
Images of the Achilles tendon in short axis will be acquired using B-mode ultrasound imaging. Maximum Achilles tendon cross-sectional area (mm\^2) will be measured by a blinded investigator.
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon neovascularization
Achilles tendon neovascularization will be evaluated using the 5-point modified Ohberg scale: 0 - no vessels visible 1. one vessel, mostly anterior to the tendon 2. one or two vessels throughout the tendon 3. three vessels throughout the tendon 4. more than three vessels throughout the tendon
Time frame: baseline, 4 weeks, 16 weeks
Change in tendon hypoechogenicity
Hypoechogenicity is indicative of disruption of the normal fibrillar structure of the Achilles tendon. Achilles tendon hypoechogenicity will be evaluated using a semi-quantitative 3-point scale: 0 - no hypoechogenicity 1. \- Heterogeneous echotexture with diffuse hypoechogenicity between fibrillar echoes and/or foci of discontinuity in collagen fibrillar echoes 2. \- Heterogeneous echotexture with discrete hypoechoic area/s of \>1mm and/or presence of intrasubstance tears
Time frame: baseline, 4 weeks, 16 weeks
Change in maximum number of heel raises
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Number of repetitions will be recorded.
Time frame: baseline, 4 weeks, 16 weeks
Change in heel raise height
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Maximum height of heel rise achieved during repetitions will be measured using the Calf Raise App.
Time frame: baseline, 4 weeks, 16 weeks
Change in heel raise work
The subject will stand barefoot on a 10° incline board and perform heel raises at a rate of 30 Hz (2 seconds per repetition, pace provided by audible metronome), while keeping their knee straight. Subjects will be allowed to have 2 fingertips per hand at shoulder height against the wall for balance. Participants will stop when they are unable to perform any additional repetitions, or if they fail to maintain proper form. Total work (body weight x total distance) will be measured using the Calf Raise App.
Time frame: baseline, 4 weeks, 16 weeks
Change in counter movement jump height
Subjects will stand on a single leg with their hands behind their back, bend their knee as much as desired, and jump as high as possible from flat ground. Three trials will be performed. Jump height will be determined using the My Jump2 App and the highest jump height will be utilized in further analysis.
Time frame: baseline, 4 weeks, 16 weeks
Change in drop counter movement jump height
Subjects will stand on a single leg on top of an 8" plyometric box, with their hands behind their back. They will be asked to "fall" down to the floor and then immediately jump as high as possible from flat ground. Three trials will be performed. Jump height will be analyzed using the My Jump2 App and the highest jump height will be utilized in further analysis.
Time frame: baseline, 4 weeks, 16 weeks
Change in VAS score during hopping
Subjects will be asked to complete two 2 trials of 25 single leg hops at a natural cadence similar to jumping rope (\~2 jumps/second). Subjects will be asked to rate their pain during the exercise using VAS (0-10).
Time frame: baseline, 4 weeks, 16 weeks
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