FRUCTOSAMINE IN OBESE NORMAL SUBJECTS AND TYPE-2 DIABETES

The effect of various grades of obesity on serum fructosamine concentr ations was studied in Type 2 diabetic (n = 105) and non-diabetic (n = 128) subjects. In obese diabetic and non-diabetic subjects (body mass index greater-than-or-equal-to 30 kg m-2), the concentration of fructo samine was markedly lower than that obtained for lean diabetic and non -diabetic subjects with similar glycaemic control. Stepwise multiple-r egression analysis showed that fructosamine was associated with glycae mic control (as indicated by fasting plasma glucose and glycated haemo globin), fasting triglycerides, and body mass index in both diabetic a nd non-diabetic subjects. In vitro studies showed marked decreases in both the extent of [C-14]-glucose incorporation into plasma proteins a nd fructosamine production by incubated sera of obese patients whether diabetic or non-diabetic, with obese subjects with body mass index > 40 kg m-2 exhibiting the greatest decrease. In conclusion, serum fruct osamine concentrations are shown to decrease in obese diabetic and non -diabetic subjects with body mass index greater-than-or-equal-to 30 kg m-2 giving rise to the underestimation of glycaemic control as indica ted by fructosamine measurement. A change in the glycation reaction it self may be partly responsible for such decrease.