Therapy of Niacin for Rheumatoid Arthritis

Inclusion Criteria: * Male or female ≥18 years of age at the time of screening, weight≥35 kg. * Diagnosed with rheumatoid arthritis satisfying the 1987 American College of Rheumatology classification criteria or ACR/EULAR 2010 classification criteria. * Stable treatment, including DMARDs (disease-modifying anti-rheumatic drugs) and glucocorticoids, was stable in dose for at least 4 weeks, and no biological agents were used during the first 12 weeks of enrollment. * Dyslipidemia (5.2≤TC≤7.2mmol/L, 3.4≤LDL-c≤4.9mmol/L or 1.7≤TG≤5.1 mmol/L) * Have given written informed consent. Exclusion Criteria: * a. Patients with other autoimmune diseases (such as systemic lupus erythematosus, Sjogren's syndrome, ankylosing spondylitis, etc.). * b. Patients with uncontrolled hyperuricemia and gout. * c. Patients who take lipid-lowering drugs such as statins or fibrates orally, cardiovascular medications (such as aspirin, nitrates, calcium channel blockers, epinephrine blockers). * d. Patients with Stevens-Johnson syndrome, toxic epidermal necrolysis, or multiple erythema. * e. Patients with significantly impaired bone marrow function or significant anemia, leukopenia, or thrombocytopenia, excepting those secondary to active rheumatoid arthritis. * f. Persistent or severe infection within 3 months prior to enrollment. * g. Uncontrolled high blood pressure, diabetes, atherosclerotic cardiovascular disease, inflammatory bowel disease, peptic ulcer and other digestive diseases, end-stage diseases, or diseases that investigators believe would put patients at risk for study participation. * h. Clinically relevant cardiovascular, liver, neurological, endocrine, or other major systemic disease that makes the implementation of the protocol or the interpretation of the findings difficult. * i. Severe liver and kidney function impairment (severe hypoproteinemia with serum albumin \<30g/L, elevated aminotransferase more than 2 times the upper limit of normal, moderate or severe renal function impairment, such as creatinine \>133 μ/L, etc.). * j. Patients with a recent and clinically severe history of drug or alcohol abuse. * k. Pregnant. * l. Breastfeeding. * m. Subjects who wish to become fathers during the study or within 24 months (or 3 months washout period) after the study; * n. Patients with congenital or acquired severe immunodeficiency, a history of cancer or lymphoproliferative disease, or patients who have received total lymphoid radiation. * o. Known HIV-positive status. * p. Patients with known hepatitis B or hepatitis C positive serology and patients with hepatobiliary diseases such as chronic active liver disease. * q. Use any biologics, such as anti-tumor necrosis factor, abaxipril, tuximab, or rituximab, within 3 months prior to the first dose. * r. Enroll in any other clinical trial involving the off-label use of investigational drugs or devices, or enroll in any other type of medical research. * s. Body mass index (BMI) less than 18.5kg/m2 or greater than 30 kg/m2.