Positive correlation of plasma PCSK9 levels with HbA1c in patients with type 2 diabetes

BackgroundProprotein convertase subtilisin/kexin type 9 (PCSK9) has been demonstrated to be involved in not only lipid metabolism but also glucose homeostasis. Glycated haemoglobin (HbA(1c)) is a gold standard' for monitoring long-term glycaemic control. However, the correlation of plasma PCSK9 levels with HbA(1c) remains undetermined. MethodsWe consecutively enrolled 805 subjects undergoing coronary angiography, including 176 patients with type 2 diabetes mellitus (T2DM) and 629 non-diabetic patients. The baseline characteristics were collected, and serum PCSK9 level was assessed by ELISA. Univariable regression analysis and multiple-variable regression analysis were used to examine the associations of PCSK9 with HbA(1c). Furthermore, the HbA(1c) was compared across the tertiles of PCSK9 levels. And also, PCSK9 levels were compared in poorly controlled (HbA(1c)7.0%) and well-controlled (HbA(1c)<7.0%) patients with T2DM. ResultsPCSK9 levels were positively correlated with low-density lipoprotein cholesterol in both T2DM and non-T2DM. Univariable regression analysis revealed a positive association between PCSK9 and HbA(1c) in patients with T2DM (=0.255, p=0.001) but not in patients without diabetes (=0.061, p=0.128). Multiple-variable regression analysis exhibited that PCSK9 was independently correlated with HbA(1c) in T2DM after adjustment for traditional atherosclerotic risk factors (=0.197, p=0.020). Moreover, HbA(1c) level was higher in patients with the highest tertile of PCSK9 than that in the lowest tertile (p=0.042). Additionally, higher levels of PCSK9 were found in poorly controlled group compared with the well-controlled group (p=0.029). ConclusionsData suggest a positive correlation of PCSK9 levels with HbA(1c) in patients with T2DM but not in patients without T2DM, indicating a potential role of PCSK9 in T2DM. Copyright (c) 2015 John Wiley & Sons, Ltd.