Moving to an A1C-Based Diagnosis of Diabetes Has a Different Impact on Prevalence in Different Ethnic Groups

Abstract

OBJECTIVETo compare screen-detected diabetes prevalence and the degree of diagnostic agreement by ethnicity with the current oral glucose tolerance test (OGTT)-based and newly proposed A1C-based diagnostic criteria.RESEARCH DESIGN AND METHODSSix studies (1999–2009) from Denmark, the U.K., Australia, Greenland, Kenya, and India were tested for the probability of an A1C ≥6.5% among diabetic case subjects based on an OGTT. The difference in probability between centers was analyzed by logistic regression adjusting for relevant confounders.RESULTSDiabetes prevalence was lower with the A1C-based diagnostic criteria in four of six studies. The probability of an A1C ≥6.5% among OGTT-diagnosed case subjects ranged widely (17.0–78.0%) by study center. Differences in diagnostic agreement between ethnic subgroups in the U.K. study were of the same magnitude as between-country comparisons.CONCLUSIONSA shift to an A1C-based diagnosis for diabetes will have substantially different consequences for diabetes prevalence across ethnic groups and populations.

Current controversies in the use of haemoglobin A1c

“…However, given that it is not known if any one test has a stronger association with complication risk, adding further complexity and potential discordance to the diagnostic criteria could be considered undesirable. A comparison of HbA 1c data from six studies, conducted in Denmark, the United Kingdom, Australia, Greenland, Kenya and India, found considerable discordance between the different diagnostic criteria which varied substantially between the six countries [58]. The probability that an individual who met plasma glucose criteria for diabetes also had an HbA 1c ‡6.5% ranged between 17 and 78% between the studies.…”

Üçüncü Basamak Bir Hastaneye Başvuran Riskli Popülasyonda Oral Glukoz Tolerans Testi ile Diabetes Mellitus ve Prediyabet Prevalansının Tespiti

“…Glukoz bakılan her merkezde OGTT ise yapılabilmektedir ve kolayca diyabet tanısı konulmaktadır. Çalışmalar göstermiştir ki OGTT 'ye karşı A1C ile diyabet tanısı konulduğu zaman prevalans düşmektedir (10).…”

Wytyczne ESC dotyczące cukrzycy, stanu przedcukrzycowego i chorób układu sercowo- -naczyniowego opracowane we współpracy z EASD

“…U ponad 60% chorych na cukrzycę typu 2 rozwija się CVD, która jest cięższym i bardziej [20]. Ograniczone dane na temat wartości HbA 1c w tej populacji wykazują duże rozbieżności w porównaniu z wynikami OGTT [21], jednak nie zostało to potwierdzone w badaniu Evaluation of Screening and Early Detection Strategies for T2DM and IGT (DETECT-2), co omówiono dokładniej w części 3.3 [22]. U Europejczyków częstość występowania cukrzycy zwiększa się z wiekiem, niezależnie od płci.…”