Contributory role of adenosine deaminase in metabolic syndrome
Adenosine deaminase (ADA) is an enzyme of purine metabolism commonly associated with severe combined immunodeficiency disease and believed to modulate bioactivity of insulin. Its contributory role in patients with metabolic syndrome (having features such as obesity, insulin resistance, fasting hyperglycaemia, lipid abnormalities and hypertension) in South Eastern Nigeria was studied. Body mass index (BMI), fasting blood glucose (FBG), Glycated haemoglobin (GHbA1c), total cholesterol, HDL-cholesterol, LDL-cholesterol (usually impaired in metabolic syndrome) and total serum ADA activity were measured in different groups of patients with metabolic syndrome (test subjects) and apparently healthy subjects (controls). The test subjects comprised six subgroups made up of the following; obese diabetic (N=25), obese non-diabetic (N=25), Non-obese diabetic (N=25), patients with hypercholesterolaemia (N=25), LDL-cholesterolaemia (N=25) and HDL-cholesterolaemia (N=25). The results showed that the mean values of all the parameters studied (BMI, FBG, GHbA1c, total cholesterol, HDL-cholesterol and LDL-cholesterol) were higher in the test subjects than their controls. BMI did not correlate significantly with FBG, GHbA1c, and ADA in the test and control subjects respectively. The mean serum ADA activity in the test subjects of obese diabetic, obese non-diabetic and non-obese diabetic subjects was higher than in controls (p< 0.001). ADA activity was also higher in the test subjects of hypercholesterolaemia, HDL-cholesterolaemia and LDL-cholesterolaemia than in control (p< 0.001). ADA activity also correlated positively with hypercholesterolemia (r = 0.640; p<0.001), HDL-cholesterolaemia (r = 0.646; p<0.001) and LDL-cholesterolaemia (r = 0.932; p<0.001), with the highest correlation in the LDL-cholesterolaemia. In conclusion, ADA activity is increased significantly in all parameters of metabolic syndrome studied and showed a significant correlation with all the three groups of dyslipidaemic subjects studied. ADA could therefore be used in daily routine laboratory assessment of most metabolic diseases especially in obese and diabetic patients.
Keywords: Diabetes Mellitus, Adenosine deaminase, Immunity, Metabolic Syndrome