Abstract
Objective: To determine a local HbA~1c~ reference range.
Design: Healthy volunteers recruited into an observational study.
Subjects: 262 healthy volunteers. Subjects were excluded if known to be diabetic or on medication known to interfere with glucose levels or if random capillary blood glucose was >10mmol/L.
Conclusion: Our local reference range for DCA 2000 measurement of HbA~1c~ has now been established and is 5.5% (+/β0.5). Two standard deviations allow the normal range to rise to 6.5%. Significant (if small) differences were seen between sex, age and ethnicity. Districts, particularly those with nonβwhite populations, should establish local reference ranges for measurement of glycated haemoglobin. This study shows that it is practical to do so.
Results: Reference range was mean 5.5% (+/β0.5). There were differences in ethnicity, sex and age. Ethnicity: Mean HbA~1c~ in which (n=135) was 5.3% (+/β0.4), which was lower than for IndoβAsians (n=127), which was 5.7% (+/β0.5):p=0.001. Sex: In females (n=140) mean HbA~1c~ was 5.4% (+/β0.45), which was lower than for males (n=122) 5.6% (+/β0.5): p=0.006. Age: For white males aged 20β44 the mean value was 5.1% compared to a mean value of 5.6% in men >65 years. White females changed from 5.0% at ages 20β44 to 5.4% for >65years. IndoβAsian females changed from 5.3% at ages 20β44 to 5.7% in women >65 years. However, for IndoβAsian men aged20β44 the mean value was 5.6% and remained at 5.6% above the age of 65 years.