Melatonin for Knee Osteoarthritis Patients

WOMAC is a self-administered, disease-specific questionnaire that assesses the severity of OA symptoms. The reliability and validity of this index have been confirmed in many clinical trials. WOMAC subscales consist of pain (5 items), stiffness (2 items), and physical function (17 items). Each item is rated from 0 to 4, totaling scores of 0-20, 0-8, and 0-68 for pain, stiffness, and function subscales, respectively.

Knee pain will be assessed by a VAS from 0 to 100, with 0 indicating "No pain" and 100 indicating "Very severe pain".

WOMAC is a self-administered, disease-specific questionnaire that assesses the severity of OA symptoms. The reliability and validity of this index have been confirmed in many clinical trials. WOMAC subscales consist of pain (5 items), stiffness (2 items), and physical function (17 items). Each item is rated from 0 to 4, totaling scores of 0-20, 0-8, and 0-68 for pain, stiffness, and function subscales, respectively.

WOMAC is a self-administered, disease-specific questionnaire that assesses the severity of OA symptoms. The reliability and validity of this index have been confirmed in many clinical trials. WOMAC subscales consist of pain (5 items), stiffness (2 items), and physical function (17 items). Each item is rated from 0 to 4, totaling scores of 0-20, 0-8, and 0-68 for pain, stiffness, and function subscales, respectively.

WOMAC is a self-administered, disease-specific questionnaire that assesses the severity of OA symptoms. The reliability and validity of this index have been confirmed in many clinical trials. WOMAC subscales consist of pain (5 items), stiffness (2 items), and physical function (17 items). Each item is rated from 0 to 4, totaling scores of 0-20, 0-8, and 0-68 for pain, stiffness, and function subscales, respectively.

PGA-OA score will be assessed using a 100 mm visual analogue scale (higher is worse).

The SF-12 questionnaire includes 8 multi-item domains (i.e., physical function, social function, role-emotional, role-physical, bodily pain, general health, mental health, and vitality). These can be combined into 2 summary measures (i.e., physical and mental component summary measures).

HADS is a self-report scale comprising 14 items. Of them, 7 evaluate depression and 7 anxiety symptoms. The score of each domain ranges from 0 to 21. The higher scores equal greater involvement of either anxiety or depression.

PSQI is a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month interval. PSQI consists of 19 self-assessments and is categorized into seven dimensions (quality of sleep, fall asleep, sleeping time, sleep efficiency, sleep disorders, hypnotic medications, and daytime dysfunction). Each dimension scores from 0 to 3 points, and the total score of the PSQI is the sum of points of seven dimensions, ranging from 0 to 21 (higher is worse).

TUG is a functional performance measure specifically for knee and hip OA. TUG directly evaluates an individual's ability to transfer, ambulate and maintain balance during transitions. TUG assesses the time it takes participants to get up from a standard-height chair, walk 3 m, turn and return to the chair, and sit down again. TUG has good interrater and intrarater reliability and validity for functional testing in older adults.

The 20-m walk test has been recommended to assess physical function in individuals with knee OA. Participants will be instructed to walk at their usual walking speed from start to finish points of a marked 20-m distance.

The chair-stand test will use a standard chair with a 47-cm seat height. Participants start the test seated, with arms crossing over the chest, and are instructed to rise to a full stand and return to the initial seated position as many times as possible in 30 s. The total number of completed chair stands is averaged across two trials and used for analysis. A greater number of chair stand repetitions is interpreted as better performance.

Both knees will be assessed with the participant supine and the knee in 30° flexion. The suprapatellar bursa will be scanned according to the Outcome Measures in Rheumatology (OMERACT) atlas. Synovial hypertrophy and effusion will be assessed using OMERACT-7 definitions. The maximal synovial thickness and effusion depth will be measured in millimeters using the longitudinal axis. Synovial hypertrophy is defined as synovial thickness ≥4 mm, and joint effusion is defined as depth of effusion ≥4 mm according to the European League Against Rheumatism (EULAR) criteria. Power Doppler signal (PDS) observed in the synovial membrane in both longitudinal and transverse planes will be scored using a semi-quantitative grading system from 0 to 3 (0 = absent, 1 = mild, 2 = moderate, 3 = marked or severe). Participants will be defined as having synovial hypertrophy or PDS if these features are present in either knee.

Patients will be permitted to use acetaminophen as rescue medication, and the consumption of rescue medication will be recorded at each visit and in the daily logs.

The blood samples will be collected in the morning after an overnight fast at baseline and the following visits. to measure the level of CRP in serum.

Stool, and saliva samples will be collected at baseline and the following visits. Microbial diversity will be quantified via the Shannon diversity index, and microbiota composition will be identified on different levels including phylum, family and genus.

Adverse events and serious adverse events will be measured and recorded.