Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol (ARBITER) 2

TLDR

Niacin lowers coronary heart disease morbidity and mortality alone or with statins, but its incremental benefit when added to background statin therapy is unknown. The study measured the change in common carotid intima‑media thickness over one year as the primary endpoint in a double‑blind randomized placebo‑controlled trial. Extended‑release niacin added to statin therapy increased HDL‑C by 21 % and slowed carotid intima‑media thickness progression, particularly in non‑insulin‑resistant patients, and was associated with fewer cardiovascular events, though the overall difference was not statistically significant.

Abstract

Niacin reduces coronary heart disease morbidity and mortality when taken either alone or in combination with statins; however, the incremental impact of adding niacin to background statin therapy is unknown.This was a double-blind randomized placebo-controlled study of once-daily extended-release niacin (1000 mg) added to background statin therapy in 167 patients (mean age 67 years) with known coronary heart disease and low levels of high-density lipoprotein cholesterol (HDL-C; <45 mg/dL). The primary end point was the change in common carotid intima-media thickness (CIMT) after 1 year. Baseline CIMT (0.884+/-0.234 mm), low-density lipoprotein cholesterol (89+/-20 mg/dL), and HDL-C (40+/-7 mg/dL) were comparable in the placebo and niacin groups. Adherence to niacin exceeded 90%, and 149 patients (89.2%) completed the study. HDL-C increased 21% (39 to 47 mg/dL) in the niacin group. After 12 months, mean CIMT increased significantly in the placebo group (0.044+/-0.100 mm; P<0.001) and was unchanged in the niacin group (0.014+/-0.104 mm; P=0.23). Although the overall difference in IMT progression between the niacin and placebo groups was not statistically significant (P=0.08), niacin significantly reduced the rate of IMT progression in subjects without insulin resistance (P=0.026). Clinical cardiovascular events occurred in 3 patients treated with niacin (3.8%) and 7 patients treated with placebo (9.6%; P=0.20).The addition of extended-release niacin to statin therapy slowed the progression of atherosclerosis among individuals with known coronary heart disease and moderately low HDL-C.