Sodium-lithium countertransport in microalbuminuric insulin-dependent diabetic patients.
A familial predisposition to arterial hypertension has recently been suggested as one important component of the susceptibility to diabetic kidney disease. Sodium-lithium countertransport activity, a marker of risk for essential hypertension, has been found to be increased in diabetic patients with overt nephropathy. We have measured red blood cell sodium-lithium counter-transport activity in 36 microalbuminuric insulin-dependent diabetic patients, a group at high risk of progression to clinical nephropathy and cardiovascular disease, and compared it with that of a matched group of 36 normoalbuminuric diabetic patients. Sodium-lithium countertransport was higher in the microalbuminuric (0.43 [95% confidence interval (CI) 0.38-0.47] mmol/l red blood cells [RBC]/hr) than in the normoalbuminuric diabetic patients (0.29 [0.25-0.33] mmol/l RBC/hr, mean difference 0.14 [0.08-0.20]; p less than 0.0001). Microalbuminuric patients had a higher frequency of parental hypertension than normoalbuminuric diabetic patients (56% vs. 28%, p less than 0.05). Sodium-lithium countertransport was related to mean arterial pressure in the microalbuminuric patients (r = 0.54, p less than 0.001) and to daily insulin requirements in both groups (microalbuminuric patients r = 0.39, p less than 0.05; normoalbuminuric patients r = 0.42, p less than 0.01). In a subset of patients in whom lipoproteins were measured, sodium-lithium countertransport activity was related to total and very low density lipoprotein triglycerides (r = 0.41, p less than 0.05 and r = 0.48, p less than 0.05) and to apolipoprotein B (r = 0.56, p less than 0.05), independently of body mass index, albumin excretion rate, glycemic control, and insulin dose.(ABSTRACT TRUNCATED AT 250 WORDS)
Jones
S L
SL
Unit for Metabolic Medicine, UMDS Guy's Hospital, London, UK.
Trevisan
R
R
Tariq
T
T
Semplicini
A
A
Mattock
M
M
Walker
J D
JD
Nosadini
R
R
Viberti
G
G
D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000378:metabolism* / Q000652:urine; D017920:Antiporters; D002319:Cardiovascular System / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism* / Q000652:urine; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism* / Q000652:urine; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
D017920:Antiporters; D002352:Carrier Proteins; C045885:sodium-lithium countertransporter