Increased plasma osteoprotegerin concentrations in Type 1 diabetes with albuminuria

The aim of the present study was to determine the plasma osteoprotegerin (OPG) levels in Type 1 diabetic patients with albuminuria.

A total of 80 Type 1 diabetic subjects and 30 control subjects were enrolled. Diabetic subjects were divided into normoalbuminuric group, microalbuminuric group and macroalbuminuric group according to urinary albumin excretion rate (UAER) and serum creatinine measurements. Plasma osteoprotegerin level was measured by enzyme-linked immunoassay.

The serum OPG levels were significantly elevated in patients with microalbuminuria (3.62 ± 0.70 ng/l) and macroalbuminuria (4.45 ± 0.76 ng/l) as compared with patients with normoalbuminuria (2.77 ± 0.78 ng/l) and control subjects (2.29 ± 0.37 ng/l). And the plasma osteoprotegerin level in macroalbuminuric group was also higher than that in microalbuminuria group. The plasma osteoprotegerin level had a positive correlation with the fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), glycohemoglobin A1c (HbA1C), highly sensitive C-reactive protein (hsCRP)and UAER. Multivariate regression analysis revealed that the plasma osteoprotegerin level was an independent factor associated with albuminuria in Type 1 diabetes.

The plasma values of osteoprotegerin were elevated in Type 1 diabetic patients with nephropathy and gradually increased with the severity, so there is a association between plasma osteoprotegerin levels and the presence and severity of diabetic nephropathy. This finding supports the growing concept that osteoprotegerin may act as an important regulatory molecule in the angiopathy, and particularly, that it may be involved in the development of nephropathy in Type 1 diabetes.