Aims/hypothesis: To study whether urinary orosomucoid excretion rate (UOER) predicts mortality in normoalbuminuric patients with diabetes at 5 years of follow-up, and to investigate the relationship between orosomucoid in serum and urine.
Methods: A cohort of 578 patients with diabetes (430 type 2, 148 type 1) was followed prospectively for an average of 5 years. UOER was measured in timed overnight urine samples.
Results: Eighty-two patients with type 2 diabetes and 17 patients with type 1 diabetes died. Among patients with type 2 diabetes, 251 (58%) had normoalbuminuria; increased UOER independently predicted cardiovascular mortality (OR 4.94, 95% CI 1.60-15.22; p<0.006) in those with normoalbuminuria and in the entire cohort of patients with type 2 diabetes (odds ratio 3.63, 95% CI 1.50-8.81; p<0.005). Patients with increased UOER had a higher all-cause mortality than those with normal UOER (log-rank test, p<0.001 for type 2 patients; p<0.04 for type 1 patients). In patients with type 1 diabetes, there were five cardiovascular deaths and no significant predictive value of UOER. Patients with increased UOER had a subclinical increase in serum orosomucoid.
Conclusion/interpretation: Increased UOER was an independent, powerful predictor of cardiovascular mortality in normoalbuminuric patients with type 2 diabetes and in the entire cohort of patients with type 2 diabetes. There were indications of UOER as being a valuable marker in type 1 diabetes that showed differences in survival between patients with normal versus increased UOER. Serum orosomucoid was associated with UOER; UOER may be a marker of low-grade inflammation in patients with diabetes.