: 1098  Synovitis can lead to tethering of tissue with loss of movement and erosion of the joint surface causing deformity and loss of function. The fibroblast-like synoviocytes (FLS), highly specialized mesenchymal cells found in the synovial membrane, have an active and prominent role in these pathogenic processes of the rheumatic joints.RA typically manifests with signs of inflammation, with the affected joints being swollen, warm, painful and stiff, particularly early in the morning on waking or following prolonged inactivity. Increased stiffness early in the morning is often a prominent feature of the disease and typically lasts for more than an hour. Gentle movements may relieve symptoms in early stages of the disease. These signs help distinguish rheumatoid from non-inflammatory problems of the joints, such as osteoarthritis. In arthritis of non-inflammatory causes, signs of inflammation and early morning stiffness are less prominent. The pain associated with RA is induced at the site of inflammation and classified as nociceptive as opposed to neuropathic. The joints are often affected in a fairly symmetrical fashion, although this is not specific, and the initial presentation may be asymmetrical. : 1098 As the pathology progresses the inflammatory activity leads to tendon tethering and erosion and destruction of the joint surface, which impairs range of movement and leads to deformity. The fingers may develop almost any deformity depending on which joints are most involved.
A 2005 study by the Mayo Clinic noted that individuals with RA have a doubled risk of heart disease, independent of other risk factors such as diabetes, excessive alcohol use, and elevated cholesterol, blood pressure and body mass index. The mechanism by which RA causes this increased risk remains unknown; the presence of chronic inflammation has been proposed as a contributing factor. It is possible that the use of new biologic drug therapies extend the lifespan of people with RA and reduce the risk and progression of atherosclerosis. This is based on cohort and registry studies, and still remains hypothetical. It is still uncertain whether biologics improve vascular function in RA or not. There was an increase in total cholesterol and HDLc levels and no improvement of the atherogenic index. Epidemiology
RA affects between 0.5 and 1% of adults in the developed world with between 5 and 50 per 100,000 people newly developing the condition each year. In 2010 it resulted in about 49,000 deaths globally.Onset is uncommon under the age of 15 and from then on the incidence rises with age until the age of 80. Women are affected three to five times as often as men.The age at which the disease most commonly starts is in women between 40 and 50 years of age, and for men somewhat later.