Cardiovascular Risk Factor Profile in RA
Patients with RA tend to have a different profile of cardiac risk factors, including a higher frequency of smoking and an altered lipid profile, compared with the general population. The lipid profile in RA is characterized by suppression of total and low-density lipoprotein (LDL) cholesterol levels during periods of high-grade inflammation, with a proportionately greater suppression of high-density lipoprotein (HDL) levels, yielding an unfavorable ratio of total to HDL cholesterol. Lipid levels have a paradoxical relationship with CAD risk in RA because lower lipid levels are associated with more severe systemic inflammation, which, in turn, is associated with increased CAD risk. Inflammation in RA also appears to alter lipoprotein structure and function; the serum amyloid A load carried by HDL increases and apolipoprotein A-I decreases, altering the usual antiatherogenic effects of HDL and resulting in proatherogenic effects.
Patients with RA are more likely to have lower muscle mass and low body mass index, which may result from uncontrolled inflammation, limitations of physical activity, or both. Low body mass in RA appears to be associated with a worsened prognosis. Cachexia, characterized by low muscle and fat mass, is now uncommon in RA, but the combination of low muscle mass and high fat mass is more prevalent in patients with RA and may be even more problematic from a heart disease perspective. Visceral adiposity in RA is associated with insulin resistance, hypertension, metabolic syndrome, and a greater inflammatory load.
Hypertension is common, and it appears to be underdiagnosed and undertreated in RA. Hypertension in RA may be exacerbated by inflammation and medications.
Increased risk of heart disease in patients with RA is associated with elevation of inflammatory markers, including CRP, erythrocyte sedimentation rate, rheumatoid factor, and anticitrullinated protein antibodies, and with more active or severe RA. Rheumatoid factor and antinuclear antibodies have been associated with heart disease and overall mortality, even in patients without rheumatic diseases.