156 SODIUM-LITHIUM COUNTERTRANSPORT ACTIVITY IN DIABETICS AND THEIR PARENTS

Abstract

We evaluated the activity of sodium lithium countertransport (SLC) in red cells of 32 diabetic children with persistent microalbuminuria (overnight Albumin Excretion Rate >30 ug/min/1.73 m2), of 32 normoalbuminuric diabetics and 32 non-diabetic matched children. SLC was significantly higher in diabetics with microalbuminuria (mean±SD, 0.47 ± 0.18 mmol of lithium/l of red cells/hour) than in diabetics without microalbuminuria (0.31 ± 0.15; p<0.01) and in normal children (0.32 ± 0.16; p < 0.01). Mean Blood Pressure (MBP) was higher in microalbuminuric diabetics than in normoalbuminuric ones and in healthy controls. SLC and MBP were significantly increased in parents of diabetics with incipient diabetic nephropathy, while they were in the normal range in parents of both normoalbuminuric IDDM patients and normal children. The predisposition to hypertension, indicated by high SLC and MBP, is evident in patients with persistent microalbuminuria.