Effect of short-term hyperglycaemia of oral glucose on red cell sorbitol and plasma glucose concentrations in diabetic and non-diabetic Nigerians.

Red cell sorbitol (RCS) haemoglobin and plasma glucose were estimated in fasting and after two hours specimens in 22 apparently healthy non diabetic and 33 diabetic Black Nigerians. Red cell sorbitol and plasma glucose were significantly higher (p < 0.001) in the diabetics than in the non diabetics. The difference between the fasting plasma glucose and after two hours was significant both in the diabetic and non diabetic subjects (p < 0.001). A similar difference for the RCS was not significant (p < 0.05) in the non diabetic subjects. This observation confirms the presence of aldose reductase in human erythrocytes and its high Michaelis constant (Km). In the diabetic patients, plasma glucose correlated positively and significantly with RCS both at fasting and after two hours (p < 0.001). Thus both the fasting and random specimens can be used for the assessment of the polyol (sorbitol) pathway in diabetic patients. The polyol (sorbitol) pathway in diabetic patients can be minimised by strict glycaemic control in these patients.