Prevalence of raised sodium-lithium countertransport activity in type 1 diabetic patients

Prevalence of raised sodium-lithium countertransport activity in type 1 diabetic patients. The prevalence of raised Na + /Li + countertransport (CT) activity (>0.41 mmol/liter RBC/hr) was assessed in 185 consecutive insulin-dependent diabetic patients attending an outpatient diabetic clinic. Normoalbuminuria was defined as an overnight albumin excretion rate (AER) of + /Li + CT (>0.41 mmol/liter RBC/hr) was 21.5, 42.8 and 51.7% (P = 0.0005), in patients with normo-, micro- and macroalbuminuria, respectively. In the whole group, Na + /Li + CT was significantly related to mean blood pressure (MBP; r s = 0.37, P s = 0.38, P + /Li + CT, MBP, duration of diabetes and glycosylated hemoglobin (HbAl). The frequency of normoalbuminuric patients with high Na + /Li + CT activity fell with duration of diabetes. The risk of proteinuria was significantly greater in patients with raised Na + /Li + CT compared to those with Na + /Li + CT within the normal range (odds ratio 3.8, 95% CI, 1.9 and 7.8). A relative excess of patients with proteinuria (micro + macroalbuminuria) was found in the group with elevated Na + /Li + CT and HbAl above the median value (8.05%) of the whole population (χ 2 = 9.7, P + /Li + CT activity is more prevalent in IDDM patients with proteinuria and is rare in long-standing normoalbuminuric patients; the risk of proteinuria increases with increasing Na + /Li + CT rates; blood glucose control and Na + /Li + CT appear to interact in determining proteinuria.