Influence of serum albumin & total protein on fructosamine measurement.

To assess the effect of serum albumin and total protein on the fructosamine level 57 hypoalbuminaemic patients (serum albumin less than 30 g/1), of whom 44 were nondiabetics and 13 were diabetics, were studied. Fructosamine levels of hypoalbuminaemic diabetics was increased only marginally in comparison to healthy controls (P greater than 0.05) whereas in 122 other normalbuminaemic diabetics, the level was found to be significantly higher (P less than 0.001). In control subjects, the correlation between fructosamine and serum albumin (r = 0.69, P less than 0.001) was better than that of total protein (r = 0.42, P less than 0.01) whereas in hypoalbuminaemic patients the pattern was reversed (r = 0.51 and 0.59 respectively), indicating substantial contribution by the globulins. A working formula suggesting approximate contribution of each gram of albumin and globulin in healthy subjects was calculated. It is inferred that the use of serum fructosamine for assessment of glycaemic status could be misleading in patients with lower albumin values. Calculating serum fructosamine values from serum albumin alone in these patients is likely to be inaccurate, as it ignores the contribution of globulins which can be substantial in certain disease conditions. A gross idea regarding the glycaemic status can be obtained by comparing actual and calculated values of fructosamine from the formula.