Alteration in serum oxidative stress balance in patients with different circulating high-density lipoprotein cholesterol levels

Introduction and Objectives: High-density lipoprotein cholesterol (HDL-C) is known to be a key player in reverse cholesterol transport and this function is associated with its atheroprotec-tive role. Low HDL-C is a strong independent risk factor for cardiovascular disease, premature atherosclerosis and increased oxidative stress. However, the clinical benefit of high HDL-C through diet or drug therapy is still controversial.Methods: This study included 50 patients with isolated low HDL-C (= 70 mg/dl), and 33 age-and gender-matched controls with normal HDL-C. 'Isolated' was defined as excluding all clinical conditions associated with increased oxidative stress and inflammation, which may affect the structural state of HDL-C. In addition to arylesterase (ARES) activity and plasma thiol levels, laboratory parameters associated with oxidative stress were also assessed.Results: Levels of ARES (758 [169-1150] vs. 945 [480-1215] and 821 U/l [266-1220]; p