Severity of glomerulopathy predicts long-term urinary albumin excretion rate in patients with type 1 diabetes and microalbuminuria.Diabetes Care. 1999 Feb; 22(2):314-9.DC
To investigate whether the degree of glomerular structural lesions in young patients with type 1 diabetes and microalbuminuria was associated with urinary albumin excretion rate (AER) 6 years later and whether the AER level was influenced by blood glucose control, blood pressure, or glomerular filtration rate (GFR).
RESEARCH DESIGN AND METHODS
There were 17 young adults with type 1 diabetes and microalbuminuria, 8 men and 9 women with mean age 20 years (95% CI: 18-22) and duration of diabetes of 11 years (10-13), who participated in a 6-year prospective study. Kidney biopsies (measurements of basement membrane thickness [BMT] and mesangial and matrix volume fractions) and GFR were performed at baseline. AER and HbA1c were measured at least three times a year and blood pressure once a year.
In a multivariate analysis, baseline BMT and mean 6-year HbA1c contributed significantly to AER at the end of the study (R2 = 0.69, P < 0.01). When mesangial volume fraction replaced BMT as the independent variable, this parameter and AER at baseline predicted the AER at 6 years (R2 = 0.55, P < 0.55). Mesangial volume fraction and BMT (in separate analysis) contributed significantly to change in AER during the study. During the study, neither AER (30 micrograms/min [19-40] to 16 micrograms/min [7-90]) nor blood pressure (96 mmHg [92-102] to 95 mmHg [91-98]) changed significantly in the group. However, HbA1c was reduced from 10.3 (9.6-11.0) to 8.4% (7.8-9.1) (P < 0.01).
In young patients with microalbuminuria, the long-term urinary AER was predicted by the degree of glomerular structural changes and associated with blood glucose control, but not with blood pressure or GFR.