Microalbuminuria following gestational diabetes

Microalbuminuria (MA) precedes clinical nephropathy in patients with insulin-dependent diabetes mellitus, and is associated with an increased mortality, mostly due to cardiovascular disease in patients with non-insulin-dependent diabetes mellitus. Microalbuminuria is rarely detected in patients with diabetes of less than five years' duration. Our study was designed to determine whether MA and its sequelae also appear 5-8 years after pregnancy complicated by gestational diabetes mellitus (GDM).

We examined the presence of MA in 72 women who had not conceived since a previous GDM-pregnancy 5-8 years ago and compared them to a control group of 35 women who had no GDM history, and who were matched for age, parity and time since last pregnancy. Microalbuminuria was determined in all subjects using an overnight 8 hours urine collection. Mann-Whitney rank-sum test was used to compare data between the study and the control groups. Student's t test was used to compare data within the study group.

Median value of the urinary albumin excretion rate (AER) in the study group was significantly higher than median value of urinary AER of the control group (p < 0.0001), but only 30.5% of the subjects of the study group were found to be microalbuminuria-positive, defined as urinary AER value of more than 21 mg/24 h. No correlation between MA and blood pressure, fasting blood glucose, serum creatinine, blood urea nitrogen and parity was found.

MA was found to be more frequent after GDM and no predisposing factors for its appearance were elucidated. Hence, we suggest that it may well be a sign of early renal disease and that long-term follow-up of all GDM patients for MA and other markers of renal disease is strongly indicated.