A longitudinal evaluation of urinary glycosaminoglycan excretion in normoalbuminuric type 1 diabetic patients.
BACKGROUND
Previously, we found high urinary glycosaminoglycan (GAG) concentration, together with an altered electrophoretic pattern, in normoalbuminuric type 1 diabetic subjects with hemoglobin A(1c) (HbA(1c)) > or =8.0%. The purpose of this study was long-term evaluation of GAG excretion variations in these patients compared to those with HbA(1c) < 8.0% at baseline who maintained better metabolic control over time.


METHODS
We enrolled 26 normotensive, normoalbuminuric type 1 diabetic patients and divided them into two groups according to mean HbA(1c) levels during the follow-up period. GAGs were isolated from 24-h urine samples on two separate occasions, at baseline and after a mean (+/-SD) follow-up of 6.8+/-1.1 years.


RESULTS
All patients remained normoalbuminuric at follow-up, and had normal urinary alpha(1)-microglobulin levels. In patients with HbA(1c) <8.0%, total GAG levels and low sulfated chondroitin sulfate-proteoglycan/chondroitin sulfate ratio were almost unchanged during the follow-up period. In contrast, these increased in patients with HbA(1c) > or =8.0% and were significantly related to both HbA(1c) levels and the duration of poor glycemic control.


CONCLUSIONS
Our results show a strong influence of hyperglycemic environment on GAG metabolism in diabetes and indicate that the distribution pattern of urinary GAGs, besides their total concentration, may be predictive of altered GAG metabolism in type 1 diabetes.
De Muro
Pierina
P
Department of Physiological, Biochemical and Cellular Science, University of Sassari, via Muroni 25, 07100 Sassari, Italy. demuro@uniss.it
Fresu
Pietro
P
Tonolo
Giancarlo
G
Maioli
Mario
M
Cherchi
Giovanni Battista
GB
Murgia
Antonio
A
Ibba
Cristina
C
Sanna
Giovanni Maria
GM
Cherchi
Gian Mario
GM