Good a1c levels for type 1 diabetes

Over the last several years a significant amount of research has proven that control matters, and good control is now defined as an A1C of < 7 per cent.

Table of Contents Show

Diabetes Control & Complications Trial (DCCT) 1982-1993
But what do these results mean for you?
DCCT/EDIC Results 1993-2005 (NEJM 2005)
How the test works
What do these numbers mean?
Sometimes the test isn’t accurate, and here’s why:
Translating your A1c to an average blood sugar level
What’s a “perfect A1C”?

What is an A1C?

An A1C test shows your blood glucose control over the last 2 or 3 months.

Diabetes Control & Complications Trial (DCCT) 1982-1993

Research from both the Diabetes Control & Complications Trial (DCCT) and its follow up study (EDIC) proves that having an A1C of 7 per cent is definitely worthwhile for persons with type 1 diabetes.

Exactly 1441 volunteers aged 13 to 39, all with type 1 diabetes, took part. These people agreed to randomly be assigned to either conventional treatment - taking about two insulin injections a day - or to intensive treatment (IT) - taking either multiple dose insulin (MDI, about 4 injections a day) or an insulin pump.

During the study the A1C of each group was compared:

the conventional therapy group had an average A1C of 9.1 per cent (normal 4-6 per cent)
the intensive therapy group had an average A1C of 7.2 per cent

The purpose was to finally demonstrate whether or not good blood sugar control was really important to prevent the complications of diabetes. And indeed it is – as you can see below, complications developed at a much lower rate in the intensively treated group compared to the conventional group.

Effect of intensive therapy on:	Those with no complications at beginning of study:	Those with some complication at beginning of study:
Eye Disease (retinopathy)	76% overall reduction	54% less progression 45% less risk of needing laser therapy
Kidney Disease (nephropathy)	34% less microalbuminuria	56% less proteinuria
Nerve Disease (neuropathy)	69% less occurrence	57% less occurrence
Heart Disease	Trend towards reduction in risk factors	Trend towards reduction in risk factors

The reduction in risk for eye disease (the primary outcome) was so great that the study was stopped early – and intensive therapy to achieve an A1C of 7 per cent or less became the standard of practice worldwide!

But what do these results mean for you?

For you, a person with type 1 diabetes, lowering your A1C by 1 per cent means a 45 per cent less risk you will develop the chronic complications of diabetes! That’s 45 per cent for each 1 per cent lower! The closer to normal (<6 per cent) the A1C is the better!

The results also mean that an A1C of <7 per cent will also be good for you if you already have some signs of chronic complications. For example, kidney and eye disease may stay stable for years!

At the end of the original DCCT trial, all the people in the conventional group changed to intensive therapy and their A1C lowered. Then both groups went back to their usual diabetes care teams, coming back to the study centre for a once yearly assessment.

This same group of volunteers has remained in the DCCT follow up study called Epidemiology of Diabetes Interventions & Complications (EDIC) since 1993. Now that’s commitment to a research study!

Over time the A1C of the original intensive therapy and the former conventional therapy groups evened out at an average of 8%, but the benefits of intensive therapy remained – much to everyone’s surprise. And for the first time, the benefits of good control on heart/cardiovascular disease were clearly shown.

DCCT/EDIC Results 1993-2005 (NEJM 2005)

Original Intensive vs. Conventional Therapy Groups: Comparison of Complications Status	EDIC 11 yrs of A1C~ 8% Both testing 4 x per day
Eyes (retinopathy)	75% less progression
Kidney	86% risk reduction in onset of new microalbuminuria
Heart/ Cardiovascular	57% less risk of heart attack (MI), stroke or CV death Intensive group: 31 people with 46 events Conventional group: 52 people with 98 events

The latest results (2005) continue to support the earliest possible adoption of intensive therapy to achieve an A1C of <7 per cent. Early and optimal blood glucose control has long term benefits.

That’s why we believe so passionately in using the IT system, and why we want to help you find the best way for you to do this. We know it isn’t easy to act like a pancreas day in and day out. It‘s hard work – and we want to help!

2015-11-20

The A1C is a blood test that helps determine if your diabetes management plan is working well. (Both Type 1 and Type 2 take this test.) It’s done every 2-3 months to find out what your average blood sugar has been. (You may also hear this test called glycosylated hemoglobin, glycohemoglobin, hemoglobin A1c, and HbA1c.) A1c is the most common name for it though.

How the test works

Essentially, the test can tell how much sugar is in the blood stream by looking for proteins (hemoglobins). When glucose (sugar) enters the blood, it binds to the protein in the red blood cells. This binding creates “glycated hemoglobin”. The more sugar in the blood, the more glycated hemoglobin.

It’s important to test your blood sugar levels (BGLs) throughout the day; however, an A1C test gives you a bigger picture with a long-term average of those blood sugar levels.

What do these numbers mean?

The A1c is an average of what your blood sugar levels have been over the 3-month period. In general, the higher your A1C number, the higher your likelihood of diabetes complications. (You don’t want a high A1C; it means there is too much sugar in your blood and your body isn’t absorbing it.)

A1C number

4.6 – 6.0	Normal (does not have diabetes)
5.7 – 6.4	Pre-diabetes (warning that someone may develop Type 2 or have the beginning onset of Type 1)
6.7+	Diabetes (someone diagnosed with diabetes)
<7.0 – 7.5	Target range (for adults diagnosed with diabetes – children diagnosed with diabetes)

This target range varies between individuals, some people naturally run a little higher, some lower. It is important to note that especially in children a higher A1C (of 7.5) is recommended. The A1C number will help you and your doctor determine though if your diabetes management plan is working well.

Learn more about children’s A1C target range.

Sometimes the test isn’t accurate, and here’s why:

If you are bleeding a lot, the protein (hemoglobin) in your red bold cells may be low, so it could say your A1C is lower than it actually is.
If you’ve just had a blood transfusion or have other forms of hemolytic anemia, your A1C test results may be lower than it actually is.
If you are low in iron in the blood, your A1C test results may be higher than it actually is.
If you have a special hemoglobin (variant). Most people have Hemoglobin A. With the variant, you can be falsely high or low. A lab test can be done to see which one you are and special lab tests can then give you an accurate A1C. (Hemoglobin variants are mostly found in black, Mediterranean and Southeast Asian populations.)
A new lab can give different results as well. Keep this in mind if your results were sent away to a new facility. It could account for minor reading variations.

Translating your A1c to an average blood sugar level

	A1C level	Estimated average blood sugar level
	5 percent	5.4 mmol/L97 mg/dL
	6 percent	7.0 mmol/L126 mg/dL
	7 percent	8.6 mmol/L154 mg/dL
	8 percent	10.2 mmol/L183 mg/dL
	9 percent	11.8 mmol/L212 mg/dL
	10 percent	13.3 mmol/L240 mg/dL
	11 percent	14.9 mmol/L269 mg/dL
	12 percent	16.6 mmol/L298 mg/dL
	13 percent	18.1 mmol/L326 mg/dL
	14 percent	19.7 mmol/L355 mg/dL

What’s a “perfect A1C”?

This is often said when someone with diabetes has met their A1C target range, (which is 5-7). Keep in mind that an A1C test like any other BGL reading is just information to guide you in your diabetes management. Some run higher while others run low – it really depends on the individual. This number can vary wildly too throughout your life. Consult your doctor to find a target A1C range and a diabetes plan that works for you.

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