Changes in lipid levels with inflammation and therapy in RA: a maturing paradigm

Dyslipidaemia is commonly observed in patients with active rheumatoid arthritis (RA), with lower total cholesterol levels as well as lower levels of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) reported in these patients than in individuals without RA. This pattern is mirrored in sepsis and other inflammatory states, suggesting systemic inflammation has the general effect of lowering circulating lipid levels. In line with such observations, suppressing inflammation with DMARDs, biologic therapies and small-molecule Janus kinase inhibitors seems to elevate levels of lipid fractions in RA, albeit in a variable manner dependent presumably upon the mechanism of action of the different agents. In addition, limited epidemiological data in patients with RA suggest increased cardiovascular disease (CVD) risk at relatively low cholesterol levels, a pattern contrasting with that observed in the population without RA. Our understanding of the potential mechanisms behind these inflammation-associated lipid changes remains suboptimal and requires further study. In clinical terms, however, use of the total cholesterol to HDL-C ratio as the lipid component of CVD risk scoring in patients with RA would seem appropriate given that these lipid parameters generally change in parallel with inflammation and suppression of inflammation. Whether alternative lipid or lipoprotein measures (or simple markers of inflammation) could improve stratification of CVD risk in RA beyond the established risk factors requires future investigation.