Haemoglobin A1 levels in Nigerian diabetic patients using microcolumn affinity chromatography.

Haemoglobin A1 (HbA1) levels were measured in forty-five diabetic Nigerians and thirteen non-diabetic controls using disposable microcolumn kits based on affinity chromatography. The effect on HbA1 results of storage of whole blood samples for 1 week at room temperature and in a refrigerator was also evaluated. The mean +/- s.d. of HbA1 levels in diabetic patients and controls were 12.1 +/- 5.6% and 5.2 +/- 0.90% respectively. The difference was highly significant, P less than 0.001. Newly diagnosed diabetic patients who had not been on any treatment had significantly higher mean value of HbA1, 14.4 +/- 5.0%, than old patients already on treatment, 9.5 +/- 2.9%, P less than 0.01. In a group of nine patients, the mean +/- s.d. of baseline HbA1 value was 10.3 +/- 4.2% and after 1 week storage of different portions of the samples at room temperature and in a refrigerator, the mean +/- s.d. respectively were 9.8 +/- 3.6% and 11.0 +/- 4.2%. There was thus a slight decrease on storage at room temperature and a slight increase during refrigeration but the observed differences were not statistically significant. It is concluded that the glyc-affinity micro-column chromatography is a satisfactory and potentially useful method for measuring HbA1 levels in tropical developing countries. The method was easy to use and the assays could be run under average ambient room temperature without recourse to use of an air-conditioned room or a special chromatography chamber.