Circannual temperature-related variation in hemoglobin A1c is unlikely to affect its use as a diagnostic test for type 2 diabetes.
BACKGROUND
To evaluate the relationship between temperature and hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) levels in Harbin of China and analyze whether these would affect diagnosis and control of diabetes.


METHODS
Two groups were investigated: 1. Routine patients come from outpatients, 2. Research subjects including 224 healthy volunteers and 391 diabetic patients, who had 5 blood specimens collected between February and June 2010. Fasting plasma glucose and hemoglobin A1c were detected.


RESULTS
In non-diabetic patients, mean HbA1c concentrations for all temperature categories were not significantly different, but mean FPG level was higher at cooler temperatures (p < 0.05). In the diabetic group, mean HbA1c concentrations were higher at cool temperatures than at very cold temperatures (p < 0.05), but mean FPG level was higher at cold temperature than at other temperature categories (p < 0.05). Both the within- and the between-subject coefficients of variation (CVs) for HbA1c were smaller than for FPG.


CONCLUSIONS
During the year of this study, there were substantial temperature fluctuations but HbA1c concentration was more stable than FPG in non-diabetic individuals. It is therefore unlikely that temperature-related variation in HbA1c could affect the use of HbA1c as a diagnostic test for type 2 diabetes, but could affect the use of HbA1c as a glycemia control test for diabetes.
Department of Clinical Biochemistry Laboratory, The 4th Affiliated Hospital of Harbin Medical University, Harbin, China.
Li
L
Xue
Hongyan
H
Liang
Xiaofeng
X
Jiang
D000328:Adult; D015415:Biomarkers / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism*; D003080:Cold Temperature; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012621:Seasons; D055815:Young Adult
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human