Other variables that could influence HbA1c test results and thus glycaemic control, were assessed and the results showed that none of the following parameters; aspirin, being on anti-retroviral drugs, erythropoietin, iron, and vitamin B12 supplements; being a smoker; alcohol intake; having splenectomy; recent transfusion; splenomegaly; arthritis; and sickle cell disease—known to affect Glycaemic control or the monitoring test (HbA1c) directly or indirectly—significantly influenced glycaemic control in any way (Table 6). The gene discussed is EPO; the disease is sickle cell disease.