A new study in patients with type 1 diabetes mellitus (T1DM) has found that renal function decline occurs in patients with microalbuminuria and in those with normoalbuminuria and is determined in both patient groups by multiple factors. Krolewski and colleagues found that renal function decline among participants of the 2nd Joslin Kidney Study, defined as a progressive loss in estimated glomerular filtration rate of ≥3.3% per year, occurred in 10% of patients with normoalbuminuria and in 35% of those with microalbuminuria.