Can metformin stabilize PCSK9 level in stable coronary artery disease patients treated with statins?

INTRODUCTION: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as an important marker of cardiovascular risk and a new target for therapeutic interventions. We aimed to study the influence of metformin on the level of circulating PCSK9 in patients with stable coronary artery disease (SCAD) and type 2 diabetes (T2DM) or metabolic syndrome (MetS), receiving moderate doses of statins used in routine clinical practice. MATERIAL AND METHODS: The study included 80 patients with T2DM or MetS receiving rosuvastatin for at least three months prior the study. MetS was diagnosed based on the Global Consensus Definition of the International Diabetes Federation (IDF). Serum level of PCSK9 was measured with an ELISA kit. RESULTS: Patients with T2DM or MetS, who took part in the research, were divided into 2 groups – those who received metformin prior the main study (21 patients – 1(st) group) and patients who did not (59 patients – 2(nd) group). Addition of metformin to the 3-month statin therapy of the 2nd group patients, divided into subgroup A (n = 27) with the addition of metformin and subgroup B (n = 29) without one, did not significantly affect the level of lipids. However, the level of circulating PCSK9 in subgroup A patients decreased, compared to subgroup B (p < 0.01). At the same time, ongoing metformin and rosuvastatin therapy in the 1(st) group patients was not accompanied by a further decrease of the PCSK9 level. CONCLUSIONS: The addition of metformin to ongoing rosuvastatin therapy did not significantly affect serum lipid levels, but stabilized the level of circulating PCSK9, compared with the group without metformin treatment.