THE EFFECT OF THYROID FUNCTION ON GLYCATED HEMOGLOBIN AND GLYCATED ALBUMIN IN PREDIABETIC EUTHYROID PATIENTS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 414-431-HPT Axis Biology
Clinical
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-415
Yongin Cho*, Dong Yeob Shin, Kwang Joon Kim, Hyeonjin Park, Kyeong Hye Park, Sena Hwang and Eun Jig Lee
Yonsei University College of Medicine, Seoul, South Korea
OBJECTIVE Recent studies have reported that TSH levels may modify glycated hemoglobin (A1c) and glycated albumin (GA), both of which are indices of glycemic control. A guideline established in 2011 suggested a method of distinguishing prediabetes with the indices; however, the association between thyroid function and A1c or GA has not yet been elucidated. Therefore, we aimed to determine the effects of thyroid hormone on A1c and glycated albumin (GA) in prediabetic patients with euthyroid status.

RESEARCH DESIGN AND METHODS A total of 205 euthyroid prediabetic patients who underwent regular health check-up in 2012 at Severance Hospital, Seoul, Korea were included in this cross-sectional, retrospective study. Prediabetes was defined as A1c between 5.7 and 6.4% or fasting blood glucose (FBG) between 100 and 125 mg/dL. A1c and glycated albumin levels were measured in these patients. TFT (free T4, T3, TSH), A1c, GA, FBG, and lipid profiles was checked.

RESULTS In this euthyroid, prediabetic population, A1C levels did not correlate with TSH level. However, GA was significantly correlated with TSH level. (r=0.432, p value < 0.01) Furthermore, after adjusting for confounding parameters affecting GA, such as glucose level, multiple linear regression analysis showed that GA is independently associated with TSH. (β = 0.312, p value < 0.05)

CONCLUSIONS While A1c was not associated with TFT results in prediabetic patients, GA was positively associated with TSH. Therefore, thyroid function does not affect the A1c-based classification of prediabetes. However, GA, which is another marker of glycemic control, is influenced by thyroid function, which limits its use in screening for prediabetes.

Nothing to Disclose: YC, DYS, KJK, HP, KHP, SH, EJL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm