Prognostic factors for the course of beta cell function in autoimmune diabetes.
This study presents a 2-yr follow-up of 281 patients, aged 15-34 yr, diagnosed with diabetes between 1992 and 1993. At diagnosis, 224 (80%) patients were positive for at least one of the following autoantibodies: islet cell antibodies (ICAs), glutamic acid decarboxylase antibodies (GADAs), or tyrosine phosphatase antibodies (IA-2As); the remaining 57 (20%) patients were negative for all three autoantibodies. At diagnosis, C-peptide levels were lower (0. 27; 0.16-0.40 nmol/L) in autoantibody-positive patients compared with autoantibody-negative patients (0.51; 0.28-0.78 nmol/L; P: < 0. 001). After 2 yr, C-peptide levels had decreased significantly in patients with autoimmune diabetes (0.20; 0.10-0.37 nmol/L; P: = 0. 0018), but not in autoantibody-negative patients. In patients with autoimmune diabetes, a low initial level of C-peptide (odds ratio, 2. 6; 95% confidence interval, 1.7-4.0) and a high level of GADAs (odds ratio, 2.5; 95% confidence interval, 1.1-5.7) were risk factors for a C-peptide level below the reference level of 0.25 nmol/L 2 yr after diagnosis. Body mass index had a significant effect in the multivariate analysis only when initial C-peptide was not considered. Factors such as age, gender, levels of ICA or IA-2A or insulin autoantibodies (analyzed in a subset of 180 patients) had no effect on the decrease in beta-cell function. It is concluded that the absence of pancreatic islet autoantibodies at diagnosis were highly predictive for a maintained beta-cell function during the 2 yr after diagnosis, whereas high levels of GADA indicated a course of decreased beta-cell function with low levels of C-peptide. In autoimmune diabetes, an initial low level of C-peptide was a strong risk factor for a decrease in beta-cell function and conversely high C-peptide levels were protective. Other factors such as age, gender, body mass index, levels of ICA, IA-2A or IAA had no prognostic importance.
Törn
C
C
Department of Medicine, University Hospital, 221 85 Lund, Sweden. Carina.Torn@med.lu.se
Landin-Olsson
M
M
Lernmark
A
A
Palmer
J P
JP
Arnqvist
H J
HJ
Blohmé
G
G
Lithner
F
F
Littorin
B
B
Nyström
L
L
Scherstén
B
B
Sundkvist
G
G
Wibell
L
L
Ostman
J
J
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001323:Autoantibodies / Q000032:analysis*; D015415:Biomarkers; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007515:Islets of Langerhans / Q000473:pathology*; D008297:Male; D011379:Prognosis; D012727:Sex Characteristics; D013997:Time Factors
D001323:Autoantibodies; D015415:Biomarkers; D002096:C-Peptide