Low LDL Associated With Coronary Atherosclerosis Burden, CVD Risk in Non-Obese Patients With RA

Among non-obese vs obese patients with rheumatoid arthritis (RA), low low-density lipoprotein (LDL) levels were found to be associated with cardiovascular (CV) features, including coronary atherosclerosis burden, plaque formation and progression, and CV disease (CVD) risk, according to study results presented at the American College of Rheumatology (ACR) Convergence 2020, held virtually from November 5 to 9, 2020. 

Research has shown that mortality is greater in patients with RA with low vs high body weight, and that patients with RA with low vs high LDL (<70 vs >70 mg/dL) have higher CVD risk.

A total of 150 patients with RA without any symptoms or diagnosis of CVD were enrolled in the current study. Abdominal obesity was defined as a waist-to-height ratio of less than 0.58 in women and less than 0.63 in men. All participants received coronary computed tomography angiography. Of the total cohort, 101 patients were evaluated for plaque progression at follow-up (average follow-up, 6.9±0.3 years). The following assessments were conducted at baseline and follow-up: obstructive disease (>50% stenosis); number of segments with plaque (segment involvement score); extensive segments with plaque (>4 segments with plaque); and coronary artery calcium.

During an average follow-up of 6.0±2.4 years, participants were assessed for the occurrence of CVD events, including myocardial infarction, cardiac death, stroke, and hospitalization for heart failure. Using adjusted robust linear regression, the researchers studied the interactions between abdominal obesity and LDL regarding formation and progression of new and prevalent atherosclerotic plaques.

After adjusting for age, sex, statin use, and diabetes, plaque burden was greater in non-obese patients with low LDL levels compared with non-obese patients with high LDL (P <.001) and obese patients with low and high LDL (P <.01 and P <.05, respectively). The effect of LDL on the risk of developing extensive or obstructive plaque disease was found to be further moderated by obesity (P_interaction =.061), with an association between low LDL levels and a greater risk of developing extensive/obstructive plaques in non-obese patients with RA (adjusted odds ratio [aOR], 4.75; 95% CI, 1.18-19.07; P =.028) vs non-obese patients with RA (aOR, 1.55; 95% CI, 0.39-6.08; P =.532).

Inflammatory markers and disease activity were comparable across groups. Low vs high levels of LDL were found to predict a greater risk for high levels of oxidized LDL in non-obese patients with RA (aOR, 5.10; 95% CI, 1.46-17.75; P =.011) vs obese patients with RA (aOR, 0.50; 95% CI, 0.11-2.21; P =.36).

Low levels of LDL in non-obese, but not obese, patients with RA were also associated with a higher risk for plaque formation in coronary segments without plaque at baseline (aOR, 4.68; 95% CI, 2.26-9.66; P <.001; P_interaction =.002), as well as with greater severity of stenosis in segments with prevalent plaque at baseline (aOR, 5.35; 95% CI, 1.62-17.67; P =.006; P_interaction =.040).

Low vs high LDL in non-obese vs obese patients was associated with a greater risk for CVD (hazard ratio, 7.94; 95% CI, 1.52-41.36; P =.015 and hazard ratio, 0.32; 95% CI, 0.04-2.40; P =.27, respectively).

“In non-obese [patients with RA], LDL [less than] 70 mg/dL may reflect higher LDL oxidation and was associated with higher baseline coronary atherosclerosis burden, new plaque formation, stenotic plaque progression and greater CVD risk than LDL [greater than] 70 mg/dL,” the researchers concluded.

Reference

Karpouzas G, Ormseth S, Hernandez E, and Budo M. Non-obese rheumatoid arthritis patients with low density lipoprotein have higher coronary atherosclerosis burden, greater plaque progression and cardiovascular event risk. Presented at: ACR Convergence 2020; November 5-9, 2020. Abstract 0485.