Glycated haemoglobin A1c for diagnosing diabetes in Chinese subjects over 50 years old: a community‐based cross‐sectional study. (9th April 2013)

• Record Type: Journal Article
• Authors: Lin, Shuo; Hu, Li; Li, Xiaofeng; Chen, Yanming; Xu, Haixia; He, Shengqing; Ren, Zhuozhuo; Tang, Xixiang; Qiu, Yawei; Xu, Jing; Mu, Panwei; Zeng, Longyi
• Is Part Of: Clinical endocrinology. Volume 80:Number 5(2014:May)
• Page Start: 656
• Page End: 661
• Publication Date: 2013-04-09
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.12202
• Languages: English
• ISSNs: 0300-0664

Abstract

<abstract abstract-type="main" id="cen12202-abs-0001"> <title>Summary</title> <sec id="cen12202-sec-0001" sec-type="section"> <title>Objective</title> <p>Little is known about using glycated haemoglobin A<sub>1</sub>c (HbA<sub>1</sub>c) to diagnose diabetes in Chinese subjects over 50 years old. This study aims to evaluate HbA<sub>1</sub>c in diagnosing diabetes and identify the optimal threshold to be used in Chinese community subjects aged over 50 years.</p> </sec> <sec id="cen12202-sec-0002" sec-type="section"> <title>Methods</title> <p>A community‐based cross‐sectional survey was conducted from October 2010 to January 2011 in Shipai community of Guangzhou, Guangdong, China. A total of 1494 subjects (72·8%) aged over 50 years were investigated. Fasting plasma glucose (FPG<sub>1st</sub>) and HbA<sub>1</sub>c were assayed in each participant. Diabetic candidates with FPG<sub>1st</sub> ≥ 5·6 mmol/l or HbA<sub>1</sub>c ≥ 39 mmol/mol (5·7%) were informed to undergo a 75‐g oral glucose tolerance test (OGTT). Diagnosis of diabetes was made by 1999 World Health Organization criteria. Sensitivity and specificity of HbA<sub>1</sub>c for diagnosing diabetes were calculated by receiver operating characteristics (ROC) curve.</p> </sec> <sec id="cen12202-sec-0003" sec-type="section"> <title>Results</title> <p>Among 1494 subjects, 161 subjects (10·8%) with previously diagnosed diabetes and 21 with missing data were excluded. Among the remaining 1312 subjects (87·8%), 861 subjects (65·6%) with either FPG<sub>1st</sub> ≥ 5·6 mmol/l or HbA1c ≥ 39 mmol/mol (5·7%) were invited to perform OGTT. Finally, 453 subjects (52·6%) performed OGTT (FPG<sub>2nd</sub> and 2‐h plasma glucose were measured) and 54 subjects (11·9%) were identified as being diabetes. The area under ROC curve was 0·916 (0·887–0·940) for HbA<sub>1</sub>c and 0·972 (0·953–0·985) for FPG<sub>2nd</sub> in diagnosing diabetes (<italic>P</italic> = 0·045). An HbA<sub>1</sub>c threshold of 48 mmol/mol (6·5%) yielded the highest combination of sensitivity (75·9%) and specificity (95·5%) for diagnosing diabetes.</p> </sec> <sec id="cen12202-sec-0004" sec-type="section"> <title>Conclusion</title> <p>An HbA<sub>1</sub>c threshold of 48 mmol/mol (6·5%) was highly specific and had a good sensitivity for diagnosing diabetes among Chinese subjects aged over 50 years with FPG ≥ 5·6 mmol/l or HbA<sub>1</sub>c ≥ 39 mmol/mol (5·7%). This threshold may be suitable for diagnosing diabetes in Chinese subjects over 50 years old.</p> </sec> </abstract>