ABSTRACT

High-density lipoprotein (HDL) cholesterol levels are associated with decreased risk of atherosclerotic disease, but also not all HDL are functionally equivalent. The functional status of HDL is closely linked to its primary protein component, apolipoprotein A-1 (ApoA-I) levels and paraoxonase 1 (PON1) enzyme. Functional changes of HDL may arise from hyperbaric oxygen therapy (HBO) induced posttranslational modification of ApoA-1 and PON1 levels. A total of 41 patients who met the research criteria were included in the study. On average, 30 sessions of HBO therapy were performed (range: 20-39). Laboratory measurements were performed at the beginning and at the end of HBO treatment in two groups of the same patients. We measured serum levels of Apo A-1, PON1, oxidized LDL (OxLDL) and routine lipid laboratory parameters to determine possible changes in HDL function with HBO therapy. As unexpected, long term HBO treatment have no effect on OxLDL and also on PON1 enzyme. However, the mean ApoA-1 values in the second group were statistically significantly increased than their pre-treatment values (P < 0.003). This preliminary study showed that HBO therapy increased the amount of serum ApoA-1. Actually, it can be assumed that the treatment of HBO does not have a negative effect on HDL functionality. The increase in ApoA-1 with HBO therapy is probably aimed at protecting against oxidative stress in patients. As a result, there is a need for larger clinical trials to determine the possible effects of HBO therapy on HDL functionality.

KEY WORDS: ApoA-1; Paraoxonase; Hyperbaric oxygen therapy; OxLDL; Inflammation; Oxidative stress; Reactive oxygen species