Inclusion criteria for OA patients:
- Kellgren-Lawrence radiological grade of 1-3 in at least one tibio-femoral joint diagnosed by screening x-ray.
- 35 to < 75 years of age at the time of signing the informed consent form.
- Bodyweight > 50 and < 150 kg and a BMI in the range 18,5-35 kg/m2.
- Are male or female.
- Is able to meet for all of the four study visits and comply with the dietary and activity restrictions.
- Can give informed consent.
Exclusion criteria for OA patients:
Medical conditions:
- History of arthroscopy or intra-articular administration of corticosteroids or hyaluronic acid into the target knee within 6 months before screening.
- Kellgren-Lawrence radiological grade of 4 in at least one tibio-femoral joint
- Previous arthroplasty of knee or hip.
- Intention of having major surgery during the timeframe of this study.
- OA related to eg. dysplasia, aseptic osteonecrosis, acromegaly, Paget disease, Stickler syndrome, hemochromatosis, gout, chondrocalcinosis (pseudogout) or calcium pyrophosphate deposition disease.
- Current treatment with beta-receptor adrenergic antagonists (beta-blockers), systemic corticosteroid treatment in doses equivalent to > 10 mg of prednisolone per day, or Vitamin K antagonists, new oral anticoagulants, fractionated and non-fractionated heparin
- Active systemic infection.
- Active systemic inflammatory or autoimmune disease.
- Symptomatic occlusive arterial disease e.g. claudication intermittens.
- Heart failure > NYHA class II.
- History of transient ischaemic attack or stroke.
- ECG findings which, in the opinion of the investigator, compromises patient safety related to HRmax-test.
- History of coronary artery disease, myocardial infarction, or other serious cardiovascular disease, as evaluated by the investigator.
- Is not currently active athlete or a highly trained individual.
Inclusion criteria for healthy subjects:
- 18 to < 75 years of age at the time of signing the informed consent form.
- Have a bodyweight within > 50 and < 150 kg and a BMI within the range 18,5-35 kg/m2.
- Are male or female.
- Is able to meet for all of the four study visits and comply with the dietary and activity restrictions.
- Can give informed consent.
Exclusion criteria for healthy subjects:
- History of arthroscopy or intra-articular administration of corticosteroids or hyaluronic acid into the target knee within 6 months before screening.
- Previous arthroplasty of knee or hip.
- Intention of having major surgery during the timeframe of this study.
- Secondary OA e.g. because of dysplasia, aseptic osteonecrosis, acromegaly, Paget disease, Stickler syndrome, hemochromatosis, gout, chondrocalcinosis (pseudogout) or calcium pyrophosphate deposition disease.
- Current treatment with beta-receptor adrenergic antagonists (beta-blockers), systemic corticosteroid treatment in doses equivalent to > 10 mg of prednisolone per day, or Vitamin K antagonists, new oral anticoagulants, fractionated and non-fractionated heparin
- Any known active systemic infection.
- Any known active systemic inflammatory or autoimmune disease.
- Symptomatic occlusive arterial disease e.g. Inermittent claudication.
- Heart failure > NYHA class II.
- History of transient ischaemic attack or stroke.
- History of coronary artery disease, myocardial infarction, or other serious cardiovascular disease, as evaluated by the investigator.
- ECG findings which, in the opinion of the investigator, compromises patient safety related to HRmax-test.
- Is not currently active athlete or a highly trained individual.
- X-ray verified Kellgren-Lawrence grade 1-4.
- Is clinically suspected of having hip OA.
Other exclusions (all subjects):
- Legal incapacity or limited legal capacity
- Inability to communicate or cooperate with the investigator or to comply with the requirements of the entire study.
- Are categorized as being very difficult to draw blood from, as evaluated by the investigator.
- Current alcohol abuse and/or inability to refrain from intake of alcoholic beverages 24 hours prior to study intervention.
- Other factors e.g. self-reported drug abuse, which in the opinion of the investigator may interfere with the study conduct.
- Site staff, study staff members and study staff family members.
- Other concomitant disease compromising or otherwise significantly affecting ECM turnover in the opinion of the investigator