Transcapillary escape rate and relative metabolic clearance of glycated and non-glycated albumin in Type 1 (insulin-dependent) diabetes mellitus

Abstract

The transcapillary escape rate and relative plasma disappearance of glycated and non-glycated albumin were measured in 25 male Type 1 (insulin-dependent) diabetic patients using a double tracer technique. The patients were divided into three groups on the basis of their urinary albumin excretion: group 1, normal albumin excretion (less than 30 mg/24 h) (n = 8); group 2, microalbuminuria (30-300 mg/24 h) (n = 9); and group 3, clinical nephropathy (greater than 300 mg/24 h) (n = 8). Six male age-matched non-diabetic persons served as control subjects. The transcapillary escape rate of glycated albumin was similar in group 1 and control subjects (4.7 +/- 2.1 versus 5.1 +/- 1.7%), but significantly increased in group 2 (7.0 +/- 1.7%, p less than 0.05) and in group 3 (7.9 +/- 3.1%, p less than 0.05). The transcapillary escape rate of glycated albumin was slightly lower than that of non-glycated albumin in all groups, but significant only in normal control subjects. No difference in the catabolic rate of glycated and non-glycated albumin was found. We conclude that the in vivo effects of glycation on the clearance and transcapillary passage of albumin are small and not likely to play any significant role in the development of late diabetic microvascular complications.

Albumin synthesis in preterm infants on the first day of life studied with [1-13C]leucine

“…The turnover of intra-and extravascular albumin (transcapillary exchange) is unknown in infants and children. In adults it is estimated to be ϳ5%/h (6). This equilibration between the intra-and extravascular albumin pool may have caused us to label the extravascular albumin partially as well.…”

Increased Transcapillary Escape Rate of Albumin in Nondiabetic Men in Response to Hyperinsulinemia

“…The technique used for assessing vascular permeability, the TER of radiolabeled albumin, provides a noninvasive way of estimating rates of albumin equilibration across the vascular membrane. Other investigators have demonstrated in the basal state an increased TER of radiolabeled albumin in diabetic patients compared with nondiabetic subjects, but the cause for this vascular abnormality remains unknown (2,5).…”

“…An increased transcapillary escape rate (TER) of albumin has been demonstrated in type I diabetic patients who have microalbuminuria or clinical nephropathy (2). In these studies, the magnitude of the permeability defect seems to be related to the severity of clinical microangiopathy, particularly nephropathy (1,2,4,5).…”

“…I ncreased microvascular permeability has been demonstrated in type I (insulin-dependent) and type II (noninsulin-dependent) diabetic patients and has been implicated in the pathogenesis of diabetic microangiopathic complications (1)(2)(3)(4)(5)(6). An increased transcapillary escape rate (TER) of albumin has been demonstrated in type I diabetic patients who have microalbuminuria or clinical nephropathy (2).…”

Hidden Complexities in the Measurement of Fructosyl-Lysine and Advanced Glycation End Products for Risk Prediction of Vascular Complications of Diabetes

“…ACE inhibitors/ angiotensin receptor blockers and lipid-lowering agents may similarly affect plasma protein AGE levels through effects on glomerular tightening and TER, respectively (13,14). These effects on plasma protein FL and AGEs have hitherto been given little consideration, except for two previous studies (13,15). In future work, awareness of these factors would likely improve risk predictor analysis.…”