REPRODUCIBILITY OF ERYTHROCYTE SODIUM-LITHIUM COUNTERTRANSPORT ACTIVITY AND AMBULATORY BLOOD-PRESSURE MEASUREMENTS IN TYPE-1 DIABETES-MELLITUS

We aimed to study the reproducibility of sodium-lithium countertranspo rt [SLCT] activity and ambulatory blood pressure monitoring [ABPM] in type 1 diabetes. We did this by performing repeated measurements of SL CT activity and ABPM in 11 recent-onset diabetic children and in 1 1 p atients with longer duration of diabetes. Both parameters were related to microalbuminuria. In the older group of diabetic children a signif icant correlation [r = 0.78, P<0.005] in SLCT activity between the fir st and second study was observed [514.3+/-186.4 vs 491.0+/- 248.0 mu m ol/l erythrocytes/h]. Diurnal systolic and diastolic blood pressure we re comparable at both time points within the same group of diabetic ch ildren [in group 1. 102.6+/-6.1 vs 108.6+/-7.6 mmHg N.S.: in group 2: 113.4+/- 10.6 vs 114.0+/-7.8 mmHg N.S. Diastolic blood pressure in gro up 1. 57.4+/-4.8 vs 65.7+/-6.9 mmHg N.S., in group 2: 70.6+/-9.1 vs 68 .5+/-5.3 mmHg N.S.]. Moreover, there was a significant correlation in both diurnal and nocturnal systolic blood pressure between the first a nd second study in the whole diabetic population. Both SLCT activity a nd blood pressure values obtained by ABPM were found to be reproducibl e individual characteristic markers in type I diabetic children.