The Study
The influence of shorter red blood cell lifespan on the rate of HbA1c target achieved in type 2 diabetes patients with a HbA1c detection value lower than 7%
This study looked at two groups of people with type 2 diabetes and compared their red blood cell lifespan to their blood sugar levels. It found that people with shorter-lived red blood cells tended to have HbA1c levels that didn’t match their actual blood sugar — but because it only looked at one moment in time, it can’t prove that short red blood cell life caused the mismatch.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
HbA1c measures average blood sugar, but it depends on how long red blood cells live. If they die early, there's less time to get coated with sugar, so HbA1c looks better than it should.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means doctors might think diabetes is under control when it’s not, leading to wrong treatment decisions.
- 234% of patients with 'good' HbA1c actually had high sugar if their red cells didn’t live long.
- 3Their real sugar levels were higher than the HbA1c showed.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Diabetes
Year
2022
Authors
Jun-ming Wang, L. Zhang, Yunru Bai, Xinli Wang, Weilin Wang, Jing Li, Saijun Zhou
Related Content
Claims (6)
Your HbA1c number isn't just about your average blood sugar — it also depends on how long your red blood cells live. The longer they stick around, the more sugar builds up on them, which can raise your HbA1c even if your blood sugar is stable.
In people with type 2 diabetes, red blood cells don’t live as long when there’s a bigger mismatch between their actual HbA1c levels and what those levels should be based on blood sugar — meaning the body’s sugar coating on blood cells doesn’t always match up with sugar levels.
If someone with type 2 diabetes has good HbA1c numbers but their red blood cells don’t live as long, their blood sugar might actually be higher than the test shows — meaning the test could be giving them a too-rosy picture of their sugar control.
Some people with diabetes might seem to have good blood sugar control based on standard tests, but if their red blood cells don’t live as long, the test could be misleading — and nearly 1 in 3 of these patients might actually have worse blood sugar levels than the test shows.
Even when blood sugar averages look good on a diabetes test, people with shorter-lived red blood cells might still have higher actual sugar levels throughout the day.
If someone with type 2 diabetes has red blood cells that don’t live as long, their A1c test might be giving a lower number than their real blood sugar levels — meaning the test could be misleading for them.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.