Progression of nephropathy in type 2 diabetic patients.
BACKGROUND
Nephropathy in type 2 diabetes is the single most common cause of end-stage renal disease (ESRD), but the decline in kidney function varies considerably between individuals, and determinants of renal function loss, early in the course of renal disease, have not been clearly identified.


METHODS
In a prospective observational study, we followed 227 (60 female) Caucasian type 2 diabetic patients with nephropathy for 6.5 (range 3 to 17) years from a baseline glomerular filtration rate (GFR) of 83 (SD30) mL/min/1.73m(2) with 7 (range 3 to 22) measurements of GFR ((51)Cr-EDTA) per patient. We evaluated determinants of (1) rate of decline in GFR, (2) risk of doubling in serum creatinine or ESRD, and (3) mortality using potential risk factors at baseline and during follow-up.


RESULTS
The mean (SD) rate of decline in GFR was 5.2 (4.1) mL/min/year. In multivariate regression analysis, higher baseline albuminuria, systolic blood pressure (SBP), hemoglobin A1c, GFR, age, and degree of diabetic retinopathy were significantly associated with increased rate of decline in GFR (R(2) (adj) 0.24). During follow-up, elevated mean albuminuria, SBP, hemoglobin A1c, and lower hemoglobin, heavy smoking, and presence of diabetic retinopathy were significantly associated with increased decline in GFR (R(2) (adj) 0.26). During follow-up, 63 patients had a doubling in serum creatinine or developed ESRD, and 79 patients died, primarily due to cardiovascular disease. In Cox regression analysis, higher baseline albuminuria, hemoglobin A1c, and SBP, together with lower GFR and hemoglobin, were significantly associated with shorter time to doubling of serum creatinine or ESRD. Higher baseline albuminuria, hemoglobin A1c, SBP, and age were significantly associated with increased mortality.


CONCLUSIONS
Our long-term prospective study of type 2 diabetic patients with nephropathy has revealed several modifiable risk factors of enhanced progression in kidney disease and increased mortality.
Rossing
Kasper
K
Department of Physiology, Steno Diabetes Center, Gentofte, Denmark. krossing@dadlnet.dk
Christensen
Per K
PK
Hovind
Peter
P
Tarnow
Lise
L
Rossing
Peter
P
Parving
Hans-Henrik
HH
D000419:Albuminuria / Q000401:mortality / Q000503:physiopathology; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology; D003404:Creatinine / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000401:mortality* / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000401:mortality* / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D044465:White People
D003404:Creatinine