Effects of Thyroid Hormone on A1C and Glycated Albumin Levels in Nondiabetic Subjects With Overt Hypothyroidism
- Mee Kyoung Kim, MD1,
- Hyuk Sang Kwon, MD, PHD1,
- Ki-Hyun Baek, MD, PHD1,
- Je Hoon Lee, MD, PHD2,
- Woo Chan Park, MD, PHD3,
- Hyung Sun Sohn, MD, PHD4,
- Kwang-Woo Lee, MD, PHD1 and
- Ki-Ho Song, MD, PHD1
- 1Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea;
- 2Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea;
- 3Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea;
- 4Department of Nuclear Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
- Corresponding author: Ki-Ho Song, kihos{at}catholic.ac.kr.
Abstract
OBJECTIVE We aimed to determine the effects of thyroid hormone on A1C and glycated albumin (GA) in nondiabetic patients with overt hypothyroidism.
RESEARCH DESIGN AND METHODS A1C levels were measured in 45 nondiabetic patients with overt hypothyroidism and 180 euthyroid control subjects. A1C, GA, fasting blood glucose (FBG), 1,5-anhydroglucitol, and erythrocyte indexes were determined in 30 nondiabetic patients with overt hypothyroidism before and after thyroid hormone replacement.
RESULTS A1C levels were higher in patients with hypothyroidism compared with control subjects. A1C levels were decreased by thyroid hormone replacement. Thyroid hormone replacement increased serum erythropoietin, reticulocyte count, and mean corpuscular hemoglobin (MCH). The change in A1C level was significantly correlated with the change in reticulocyte count or MCH. Thyroid hormone replacement decreased serum levels of albumin and GA. However, FBG and 1,5-anhydroglucitol levels were not altered.
CONCLUSIONS Levels of A1C and GA are spuriously high in nondiabetic patients with overt hypothyroidism.
Footnotes
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
- Received May 23, 2010.
- Accepted August 29, 2010.
- © 2010 by the American Diabetes Association.
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