U.S. doctors online nowAsk doctors free
Houston, TX
A 58-year-old male asked:

M58, my fasting blood sugar and a1c don't match, for example fasting is 150 and a1c is 5.7 why is it so? both done at one month interval.

2 doctor answers2 doctors weighed in
Dr. Dan Fisher
Internal Medicine 28 years experience
Looks good.: A1c integrates blood sugar values over the last 60 days whereas the fbg is just a simple point in time. The discordance suggests that your blood glucose is well controlled over the "rest" of the day.
Dr. Stanley Schwartz
Endocrinology 53 years experience
A1c reflects: Average sugar for every second for 3months fingerstick sugar reflects blood sugar that 1 second in time :) so often they don't match.

90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more. Get help now:

Ask doctors free
Educational text
Talk to a doctor
24/7 visits - just $39!
50% off with $15/month membership
Last updated Feb 5, 2014


Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.