New diabetes diagnostic threshold of hemoglobin A(1c) and the 3-year incidence of retinopathy.
The new diagnostic threshold of hemoglobin A(1c) was made based on evidence from cross-sectional studies, and no longitudinal study supports its validity. To examine whether hemoglobin A(1c) of 6.5% or higher defines a threshold for elevated risk of incident retinopathy, we analyzed longitudinal data of 19,897 Japanese adults who underwent a health checkup in 2006 and were followed up 3 years later. We used logistic regression models and restricted cubic spline models to examine the relationship between baseline hemoglobin A(1c) levels and the prevalence and the 3-year incidence of retinopathy. The restricted cubic spline model indicated a possible threshold for the risk of incident retinopathy at hemoglobin A(1c) levels of 6.0-7.0%. Logistic regression analysis found that individuals with hemoglobin A(1c) levels of 6.5-6.9% were at significantly higher risk of developing retinopathy at 3 years compared with those with hemoglobin A(1c) levels of 5.0-5.4% (adjusted odds ratio, 2.35 [95% CI 1.08-5.11]). Those with hemoglobin A(1c) levels between 5.5 and 6.4% exhibited no evidence of elevated risks. We did not observe a threshold in the analysis of prevalent retinopathy. Our longitudinal results support the validity of the new hemoglobin A(1c) threshold of 6.5% or higher for diagnosing diabetes.
Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA. ytsugawa@bidmc.harvard.edu
Yusuke
Y
Tsugawa
Osamu
O
Takahashi
James B
JB
Meigs
Roger B
RB
Davis
Fumiaki
F
Imamura
Tsuguya
T
Fukui
William C
WC
Taylor
Christina C
CC
Wee
D000328:Adult; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged
D006442:Glycated Hemoglobin