Diabetes Care, Vol 20, Issue 7 1108-1110, Copyright © 1997 by American Diabetes Association
Low prevalence of antibodies to GAD65 in a 50- to 74-year-old general Dutch population. The Hoorn Study
JB Ruige, MR Batstra, HJ Aanstoot, LM Bouter, GJ Bruining, JN De Neeling and RJ Heine
Institute for Research in Extramural Medicine, Vrije Universiteit, Amsterdam, The Netherlands. jb.ruige.emgo@med.vu.nl
OBJECTIVE: To assess the prevalence of antibodies to GAD65 (GAD65-A) in
relation to glucose tolerance disturbances and to blood glucose-lowering
therapy in a general Dutch population. RESEARCH DESIGN AND METHODS: A
population sample of 2,350 Dutch subjects, age 50-74 years, agreed to
undergo an oral glucose tolerance test (OGTT). They were classified as
having normal glucose tolerance, impaired glucose tolerance, newly detected
diabetes, or known diabetes. GAD65-A levels were measured in serum by means
of a standardized radioligand assay and subsequently were expressed as
indexes. The prevalence rates were defined as the proportions of
individuals of each category of glucose tolerance exceeding the value of
the index at the 99th percentile of the entire study population. RESULTS:
The prevalence rates and the 95% CIs of GAD65-A were 0.7% (0.4-1.2%) in
cases of normal glucose tolerance, 2.4% (0.9-5.3%) in impaired glucose
tolerance, 0% (0-3.3%) in newly detected diabetes, according to the World
Health Organization (WHO) criteria, and 3.5% (0.7-10.0%) in known diabetes.
A total of 2 out of 3 subjects with GAD65-A indexes above the 99th
percentile and 10 out of 18 subjects with GAD65-A indexes above the 85th
percentile received insulin therapy for their diabetes, which showed an
association between GAD65-A and insulin therapy CONCLUSIONS: Low prevalence
rates of latent autoimmunity to GAD were found in 50- to 74-year-old Dutch
subjects with normal and abnormal glucose tolerance, and GAD65-A was
associated with insulin use in known diabetic subjects.