Protein Turnover in Healthy and Overuse-diseased Tendon

Study Overview
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Brief Summary
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The goal of this clinical trial is to examine the regional protein turnover in tendon tissue from patients with chronic patellar tendinopathy and comparing this to healthy controls. Further we will examine the effect of resistance training on protein turnover in healthy individuals.

Official Title
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Protein Turnover in Healthy and Overuse-diseased Tendon

Conditions
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Patella; Tendinitis

Intervention / Treatment
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* Other: Progressive resistance training
* Other: Cross-sectional comparison between healthy and tendinopathic group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physical active men and women Body mass index 18,5 - 30 kg/m2 Inclusion Criteria for the chronic tendinopathy group: Debut of symptom > 90 days prior to inclusion. Subjective activity related pain in patella tendon. Clinical symptoms of patella tendinopathy. Ultrasound verification of at least 1 in three of the following: Enchanced anterior-posterior diameter, increased Doppler signal and/or a hypoechoic area in the diseased part of the tendon. Exclusion Criteria for all participants: Former knee surgery or injuries to the patella tendon. Local injection of corticosteroids within 12 months. Medication that affects protein synthesis in tendon tissue. Former/current use of anabolic steroids or growth hormone. Smoking Known rheumatoid disease or diabetes. Former participation in trials using deuterated water and 15N tracers. Treatment for patella tendinopathy within 3 months.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Chronic tendinopathy patients<br> | Other: Cross-sectional comparison between healthy and tendinopathic group<br>* Comparison of primary and secondary outcomes.<br>|
| Experimental: Healthy controls<br> | Other: Progressive resistance training<br>* Only the control group: 3 exercise bouts within the study period. Comparison between exercised and non-exercised leg.<br>Other: Cross-sectional comparison between healthy and tendinopathic group<br>* Comparison of primary and secondary outcomes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Protein turnover in tendon tissue from patients with chronic tendinopathy compared to healthy controls | Fractional synthesis rate (FSR) measured in % pr. day in the trypsin-soluble and trypsin-insoluble fraction | 8 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tracer incorporation in isolated fractions of the tendon | 15N hydroxyproline enrichment measured in Mole percent Excess in the trypsin-soluble and trypsin-insoluble fraction | 8 days | 
| Tracer incorporation in isolated fractions of the tendon | 15N proline enrichment measured in Mole percent Excess in the trypsin-soluble and trypsin-insoluble fraction | 8 days | 
| Anterior-posterior dimensions of patella tendon | Measured in millimeter | 8 days | 
| Doppler flow in patella tendon | Classified in grading system from 0-3. | 8 days | 
| Subjective pain in patella tendon | Questionnaire | 8 days | 
| Subjective measure of physical activity and function | Questionnaire | 1 day | 
| Single-leg decline squat test | Subjective pain on a scale from 0-10 | 1 day | 
| One leg knee extension strength test | Only control-group. | 8 days | 
| Leg press strength test | Only control-group. | 8 days |