The Presence and Consequence of Nonalbuminuric Chronic Kidney Disease in Patients With Type 1 Diabetes

OBJECTIVE This study investigated the prevalence of nonalbuminuric chronic kidney disease in type 1 diabetes to assess whether it increases the risk of cardiovascular and renal outcomes as well as all-cause mortality. RESEARCH DESIGN AND METHODS This was an observational follow-up of 3,809 patients with type 1 diabetes from the Finnish Diabetic Nephropathy Study. All patients were Caucasians and thoroughly examined at baseline. Their mean age was 37.6 +/- 11.8 years and duration of diabetes 21.2 +/- 12.1 years. Follow-up data on cardiovascular and renal outcomes and mortality were retrieved from registers. During 13 years of median follow-up, 378 developed end-stage renal disease, 415 suffered an incident cardiovascular event, and 406 died. RESULTS At baseline, 78 (2.0%) had nonalbuminuric chronic kidney disease. This was associated with older age, female sex, history of retinal laser treatment, cardiovascular events, and the number of antihypertensive drugs in use, but not with blood pressure levels or specific antihypertensive agents. Nonalbuminuric chronic kidney disease did not increase the risk of albuminuria (hazard ratio [HR] 2.0 [95% CI 0.9-4.4]) or end-stage renal disease (HR 6.4 [0.8-53.0]) but did increase the risk of cardiovascular events (HR 2.0 [1.4-3.5]) and all-cause mortality (HR 2.4 [1.4-3.9]). The highest risk of cardiovascular and renal end points was observed in the patients with albuminuria. CONCLUSIONS Nonalbuminuric chronic kidney disease is not a frequent finding in patients with type 1 diabetes, but when present, it is associated with an increased risk of cardiovascular morbidity and all-cause mortality but not with renal outcomes.