Endocrine Abstracts

Background: We present an interesting case of a 56 year old male who, during pre–operative work up, was found to have a very low HbA1C 3.1% (10 mmol/mol). The patient was also noted to have mild thrombocytopenia, raised bilirubin and alanine aminotransferase and moderate splenomegaly on CT scan, with otherwise normal appearance of remaining abdominal viscera. His past medical history included alcohol excess (60–80 units/week), he was not diabetic and was taking Aspirin and Atorvastatin. It was felt his HbA1c was artefactually low due to increased red cell breakdown associated with splenomegaly.

Discussion: HbA1c is a validated, internationally recommended test for the diagnosis of diabetes, though HbA1c can become falsely lowered in clinical scenarios which lead to increased red cell turnover and therefore decreased opportunity for glycation of HbA1. Several population based cohort studies have investigated the link between very low HbA1c and mortality outcomes in non–diabetic adults, with varied results. Most agree there is a statistically significant link between very low HbA1c and all–cause mortality, though this becomes insignificant when adjusted for lifestyle and co–morbidity factors, and indeed the well–known “J–shaped curve” effect was subsequently accounted for when additional adjustment for liver function derangement was applied to their data set. Whilst very low HbA1c may not be an independent risk factor for increased mortality, there is potential for the finding to be a surrogate marker of increased all–cause mortality, and the authors would suggest this finding should not be quickly discounted as insignificant, but should prompt a thorough multi–systems assessment for potential underlying pathology. The patient in this case awaits Haematological work up of his splenomegaly, the cause of which has not yet been defined.