Introduction: Carbamylated low-density lipoprotein (cLDL) has profound proatherogenic properties. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been identified as the primary cLDL receptor. The soluble form of LOX-1 (sLOX-1) and 3-nitrotyrosine (NT) have recently been suggested as biomarkers of vascular disease. Although type 2 diabetes mellitus (T2DM) is characterised by an increased atherosclerotic risk, the clinical data on cLDL, NT and sLOX-1 levels in T2DM are limited.
Aim: To explore the possible role of cLDL, NT and sLOX-1 as potential biomarkers for disease progression and complications in poorly controlled T2DM patients with and without microalbuminuria.
Materials and methods: The serum concentrations of cLDL, NT and sLOX-1 were measured by ELISA in a cross-sectional study of 60 T2DM patients and 35 nondiabetic controls.
Results: Both the normoalbuminuric (n = 34) and the microalbuminuric (n = 26) patients had significantly higher serum levels of cLDL and NT than the healthy controls, but sLOX-1 was only elevated in the microalbuminuric subgroup (p < 0.05). Carbamylated LDL correlated positively with NT in the diabetic subjects (rs = 0.266, p = 0.04) while it correlated with urea only in the control group (rs = 0.475, p = 0.004). The serum concentration of sLOX-1 correlated significantly with fasting glucose (rs = 0.441, p < 0.001), HbA1c (rs = 0.328, p = 0.01) and microalbuminuria (rs = 0.272, p = 0.035) in the whole diabetic cohort.
Conclusions: The present study highlights the potential of cLDL, NT and sLOX-1 as possible markers of diabetic complications.
Keywords: diabetes mellitus; microalbuminuria; nitrotyrosine; sLOX-1; carbamylated LDL.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.