A review of the effects of biological modifiers suggests the ratio between HDL and total cholesterol as a marker of cardiovascular risk.
Popa CD, Arts E, Fransen J, van Piel PL. Atherogenic Index and High-Density Lipoprotein Cholesterol as Cardiovascular Risk Determinants in Rheumatoid Arthritis: The Impact of Therapy with Biologicals. Mediators Inflamm. (2012) 2012:785946. (Published online Sept. 6, 2012.) doi: 10.1155/2012/785946
Although cardiovascular disease is the chief cause of death among rheumatoid arthritis (RA) patients, this is not adequately explained by the usual risk factors such as hypertension, smoking, and physical inactivity. The impact of dyslipidemia has been difficult to assess, because lipid levels fluctuate with the course of disease..
What is the impact of biological therapy on lipid levels? The question has not been addressed systematically, according to the authors of this literature review, rheumatologists from Radboud University Nijmegen Medical Center in the Netherlands. They have taken a careful look at the relationship between biological therapy and the atherogenic index (AI), the ratio between total cholesterol and high density lipoprotein (HDL), which the evidence suggests is less likely than other lipid indicators to fluctuate with disease activity.
Although HDL's value as a marker in CV is unclear for most populations, they write, in patients with RA its anti-atherogenic properties may make it a valuable marker of cardiovascular risk.
Small studies by the authors themselves have found a significant 8% decrease in AI after 2 weeks of adalimumab treatment compared to placebo. On the other hand, AI increased significantly after almost 6 months of treatment with infliximab. Changes reported in such short-term studies are often not sustained over the long term, they report. Responders to treatment appear to show more significant effects than non-responders, although the question has not been studied in well-powered trials designed to address the issue.
Overall, etanercept, adalimumab, and rituximab appear to have a positive although often short-lived impact on AI, while some studies agree with the authors' finding that infliximab may worsen lipid ratios. In general, they write, controlling disease activity and achieving remission appears to have a beneficial impact on the lipid pattern
As cardiovascular risk management becomes an integrated part of treating RA, they conclude, the choice of appropriate biological therapy in light of the individual patient's lipid profile "will become of crucial value."