Islet antibodies associated with pancreatic B-cell dysfunction at and 3 years after diagnosis of diabetes in subjects aged 35-64 years old: degree of impairment less severe than in those aged 0-34 years old.
OBJECTIVE
To determine differences in pancreatic B-cell function in relation to islet antibodies at diagnosis of diabetes and 3 years later in subjects aged 35-64 years old compared with those aged 0-34 years.


METHODS
From a population-based diabetes register, 46 (0-34 years old) and 323 (35-64 years old) incident diabetic patients were investigated at diagnosis and 3 years later. Islet cell antibodies (ICA, GADA and IA-2A) and fasting plasma C-peptide were measured.


RESULTS
Islet antibodies were found in 80% of the subjects aged 0-34 years and in 11% of those aged 35-64 years at diagnosis. ICA and GADA was the only combination of two islet antibodies detected in those aged 35-64 years and was, with or without IA-2A, associated with significantly lower median fasting C-peptide values than in those without or with only one antibody [0.35 nmol/l, interquartile range (IQR) 0.63 vs. 0.85 nmol/l, IQR 0.49; P = 0.0004]. However, fasting C-peptide in subjects aged 35-64 years old with multiple islet antibodies was higher than in those aged 0-34 years with islet antibodies (median 0 nmol/l, IQR 0.16, P = 0.0019). After 3 years' follow-up, fasting C-peptide was even lower in subjects aged 35-64 years old with three islet antibodies (median 0.14 nmol/l, IQR 0.27; P = 0.05).


CONCLUSIONS
Islet antibodies were common in adults at diagnosis of diabetes. The combination of ICA and GADA indicates impaired B-cell function at diagnosis of diabetes in those aged 35-64 years old.
Berger
B
B
Department of Medicine, Skaraborg Hospital, Skövde, Sweden. bo.berger@vgregion.se
Borg
H
H
Fernlund
P
P
Stenström
G
G
Sundkvist
G
G
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000276:immunology*; D002096:C-Peptide / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003920:Diabetes Mellitus / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D050417:Insulin-Secreting Cells / Q000276:immunology*; D007515:Islets of Langerhans / Q000276:immunology*; D008875:Middle Aged
D001323:Autoantibodies; D002096:C-Peptide; C024211:islet cell antibody