Low risk of overt nephropathy after 24 yr of childhood-onset type 1 diabetes mellitus (T1DM) in Norway.
OBJECTIVE
To estimate the risk of diabetic nephropathy and associated risk factors in a nationwide cohort of childhood-onset type 1 diabetes mellitus (T1DM) and 19-30 yr of diabetes duration.


METHODS
Patients diagnosed with childhood-onset T1DM (<15 yr) from 1973 through 1982, who previously (1989-1990) participated in a clinical examination to assess diabetic complications, were invited for a new examination in 2002-2003. Of 355 eligible patients, 299 participated (84.2%), and complete urine samples for evaluation of albuminuria were obtained from 295 patients, with a mean age of 33 yr (range 20.9-44.0) and mean diabetes duration of 24 yr (range 19.3-29.9). Persistent microalbuminuria and overt nephropathy [albumin excretion rate (AER) 15-200 microg/min and AER > 200 microg/min, respectively] in at least two out of three consecutive overnight urine samples were defined as diabetic nephropathy.


RESULTS
Overt nephropathy was found in 7.8% [95% confidence interval (CI) 4.7-10.9] and persistent microalbuminuria in 14.9% (95% CI 10.8-19.0) of the subjects. Hemoglobin A1c (HbA1c) (p = 0.001), systolic blood pressure (BP) (p = 0.002), total cholesterol (p = 0.019), and C-reactive protein (CRP) (p = 0.019) were associated with diabetic nephropathy. Significant predictors in 1989-1990 for the development of diabetic nephropathy in 2002-2003 were HbA1c (p < 0.001), AER (p = 0.007), and cholesterol (p = 0.022).


CONCLUSIONS
In a subgroup of patients diagnosed with childhood-onset T1DM in 1973-1982, 7.8% had overt nephropathy after 19-30 yr of diabetes duration, which is low compared with studies from other countries. HbA1c, systolic BP, total cholesterol, and CRP were each independently associated with diabetic nephropathy.
Skrivarhaug
Torild
T
Department of Pediatrics, Ullevål University Hospital, Oslo, Norway. torild.skrivarhaug@medisin.uio.no
Bangstad
Hans-Jacob
HJ
Stene
Lars C
LC
Sandvik
Leiv
L
Hanssen
Kristian F
KF
Joner
Geir
G
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure; D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D002784:Cholesterol / Q000097:blood; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D015994:Incidence; D008297:Male; D009664:Norway / Q000453:epidemiology; D018570:Risk Assessment; D013997:Time Factors
D002097:C-Reactive Protein; D002784:Cholesterol; D006442:Glycated Hemoglobin