Metformin Use in Rheumatoid Arthritis

Study Overview
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Brief Summary
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Metformin has been used clinically for over 50 years, as a glucose lowering agent. Direct and indirect anti-inflammatory effects of metformin have been reported in animal and clinical studies, and this effect is independent of its hypoglycemic effect. Animal studies showed that metformin decreased serum C-reactive protein (CRP) level in atherogenic rabbits and decreased proinflammatory cytokines (interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF-α) in obese mice . Moreover, metformin also suppressed osteoclastogenesis ; this may partially result from decreased expression of inflammatory cytokines that promote osteoclastogenesis in the arthritic joint. The objective of this study is to evaluate the efficacy and safety of addition of metformin to standard disease modifying anti-rheumatic drugs (DMARDs) in patients with rheumatoid arthritis.

Official Title
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The Effect of Metformin on the Clinical Outcome of Patients With Rheumatoid Arthritis

Conditions
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Rheumatoid Arthritis

Intervention / Treatment
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* Drug: Metformin
* Drug: Conventional DMARDs
* Drug: Placebo Oral Tablet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients older than 18 years (of both sexes) diagnosed with rheumatoid arthritis according to ACR / EULAR 2010 criteria . Patients with moderate to high disease activity (DAS - 28 . score greater than 3.2) Patients received the standard therapy (i.e. one or more conventional DMARDs) for at least three months. Exclusion Criteria: Known hypersensitivity to metformin. Patients who have a prior diagnosis with diabetes mellitus. Patients receive metformin for any other indications. Patients with congestive heart failure. Patients with a history of myocardial infarction. Patients with severe anemia. Patients with active infections or other inflammatory diseases. Patients receiving biological therapy. Pregnancy or lactation. Patients with impaired liver functions. Patients with impaired kidney functions (serum creatinine concentrations ≥1.5 and ≥1.4 mg/dL in males and females respectively). Patients with malignancies.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Metformin Group<br>850 mg metformin twice daily for six months in addition to standard therapy | Drug: Metformin<br>* metformin 850 mg bid for RA patients with moderate to high disease activity provided by DAS-28 score greater than 3.2<br>Drug: Conventional DMARDs<br>* methotrexate, leflunomide, hydroxychloroquine or sulfasalazine<br>|
| Active Comparator: Control Group<br>placebo in addition to standard therapy for rheumatoid arthritis | Drug: Conventional DMARDs<br>* methotrexate, leflunomide, hydroxychloroquine or sulfasalazine<br>Drug: Placebo Oral Tablet<br>* oral tablet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| disease activity scale in 28 joints ( DAS-28) | scale assessing severity of rheumatoid arthritis based on number of tender , swollen joints , ESR levels ,and patient self-assessment of his condition (global health assessment) . Whereas 28 describes the number of different joints including in the measurement :proximal interphalangeal joints (10 joints),metacarpophalangeal joints (10),wrists (2),elbows (2),shoulders (2),knees (2). DAS28 values range from 2 to 10 while higher values mean a higher disease activity. A DAS-28 value < 2.6 corresponds to remission,value between 2.6 and 3.2 corresponds to a low disease activity, value between 3.2 and 5.1 corresponds to a moderate disease activity, and DAS28 value >5.1 corresponds to a high disease activity. | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| C reactive protein levels | blood samples will be withdrawn at baseline and after 3 and 6 months to evaluate serum levels of C reactive protein | 6 months | 
| The HAQ (Health Assessment Score) | HAQ-DI (Health Assessment Score- Disability index), in which patients are asked to rate their capacity to perform 20 activities of daily living (ADL). Scoring within each section is from 0 (without any difficulty) to 3 (unable to do). For each section the score given to that section is the worst score within the section, The Standard Disability Index (DI) calculated as the sum of the scores for various subscales divided by the number of subscales responded to, and results in a score between 0 and 3.Whereas scores can be interpreted as: From 0 to 1: mild difficulties to moderate disability, 2: moderate, 3: severe to very severe disability. | 6 months | 
| serum adiponectin level | blood samples will be withdrawn at baseline and after 3 and 6 months to evaluate serum adiponetin levels using ELISA kits | 6-months | 
| adverse effect incidence | adverse effect will be reported by patients or their caregivers and recorded by investigator | 6 months |