Urinary PC-1 activity in patients with type 1 diabetes mellitus

Area of Science:

• Endocrinology
• Nephrology
• Biochemistry

Background:

• Insulin resistance is a key feature of type 1 diabetes mellitus (T1DM) with nephropathy.
• The molecular underpinnings of insulin resistance in T1DM remain incompletely elucidated.
• Transmembrane glycoprotein PC-1 (alkaline phosphodiesterase I) has emerged as a potential contributor to insulin resistance.

Purpose of the Study:

• To investigate the urinary excretion patterns of PC-1 and N-acetyl-beta-D-glucosaminidase (NAGA) in type 1 diabetic patients.
• To correlate PC-1 and NAGA urinary levels with the presence and severity of kidney damage in T1DM.

Main Methods:

• Urinary PC-1 and NAGA excretion were measured in 62 type 1 diabetic patients with varying degrees of nephropathy.
• Patient groups included newly diagnosed, those under insulin therapy, and individuals with microalbuminuria, manifest nephropathy, renal failure, and primary glomerulonephritis.

Main Results:

• Newly diagnosed T1DM patients, prior to insulin therapy, exhibited significantly increased urinary PC-1 excretion compared to controls.
• After approximately 12.4 years of insulin therapy, urinary PC-1 levels significantly decreased.
• Decreased urinary PC-1 activity was observed in T1DM patients with microalbuminuria, manifest nephropathy, and renal failure.
• Urinary NAGA excretion was significantly elevated in all T1DM groups except those without nephropathy.

Conclusions:

• Urinary PC-1 excretion is elevated in newly detected T1DM patients with poor glycemic control.
• Conversely, urinary PC-1 excretion is decreased in T1DM patients with micro-/macroalbuminuria and those without apparent kidney damage.
• In T1DM patients with primary glomerulonephritis, urinary PC-1 was decreased while NAGA was increased compared to healthy controls.