Research from Ghana shows that standard blood tests may underestimate blood sugar levels in individuals with sickle cell trait, risking missed prediabetes or diabetes diagnoses due to assay interference.
People living with sickle cell trait may be at greater risk of having prediabetes or diabetes missed because a standard blood test can read glucose control too low, according to Ghanaian researchers who presented their findings at ADLM 2026 in Anaheim, California. The study suggests that the method used to measure HbA1c, a test that reflects average blood sugar over roughly 2 to 3 months, can materially change who is classified as having normal blood sugar and who is not.
In the Ghana study, researchers reviewed 1,283 HbA1c tests from adults at a tertiary hospital in Accra in January and February 2026. They compared immunoturbidimetry, a common laboratory technique, with high-performance liquid chromatography, or HPLC, which can identify haemoglobin variants. Where the blood had normal haemoglobin, the two approaches tracked closely. But among the 198 participants with sickle cell trait, immunoturbidimetry produced much lower readings than HPLC, enough to shift a significant share of patients out of the prediabetes and diabetes ranges.
Dr Elikem Kumahor, the study’s lead author and a specialist laboratory physician at Korle Bu Teaching Hospital, said the findings matter particularly in Ghana, where sickle cell trait is widespread and haemoglobin variants may complicate diabetes testing. The researchers reported an average HbA1c of 5.1% with immunoassay versus 5.9% with HPLC in people with sickle cell trait. Using the lower-reading method, only 11.1% were classed as having prediabetes, compared with 34.5% by HPLC, while HPLC identified 4% as meeting the diabetes threshold and immunoassay identified none.
The concerns are not new. A 1998 study in Diabetes Care found that sickle cell trait and haemoglobin C trait could distort HbA1c results when immunoassay methods were used, creating the risk of misdiagnosis or poor diabetes management. Later case reports and reviews have reached similar conclusions, warning that haemoglobin variants can interfere with specific assay techniques and that clinicians may need to consider alternative markers such as fructosamine when results do not fit the clinical picture. The Ghana findings add fresh evidence that the problem remains relevant in West Africa, where sickle cell trait is common and routine screening may depend heavily on the test platform used.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
