Increased blood pressure and erythrocyte sodium/lithium countertransport activity are not inherited in diabetic nephropathy.
Genetic predisposition to essential hypertension, represented by maximal erythrocyte sodium/lithium countertransport activity, has been suggested as a marker for the risk of developing clinical nephropathy in Type 1 (insulin-dependent) diabetes mellitus. To evaluate this hypothesis we measured arterial blood pressure and maximal sodium/lithium countertransport activity of erythrocytes in 80 parents of 49 Type 1 diabetic patients with clinical nephropathy, 78 parents of 49 normoalbuminuric patients and 17 age-matched non-diabetic individuals. The two diabetic groups were carefully matched. In the two groups of parents blood pressure and cell sodium/lithium countertransport activity showed no significant differences (137/83 vs 133/81 mm Hg and 0.33 vs 0.32 mmol/(1 cells x h) respectively). The proportion of parents who had died or received antihypertensive drugs was similar in the two groups. The patients with Type 1 diabetes had significantly higher sodium/lithium countertransport compared to the 39 non-diabetic control subjects independently of the presence or absence of nephropathy (p less than 0.002). However, patients with nephropathy tended to have higher sodium/lithium countertransport activity than normoalbuminuric patients (0.48 vs 0.41 mmol/(1 cells x h), p = 0.06). We conclude that genetic predispositions to essential hypertension and increased maximal erythrocyte sodium/lithium countertransport activity do not appear to be risk markers for the development of clinical nephropathy in Type 1 diabetic patients.
Jensen
J S
JS
Steno Memorial Hospital, Gentofte, Denmark.
Mathiesen
E R
ER
Nørgaard
K
K
Hommel
E
E
Borch-Johnsen
K
K
Funder
J
J
Brahm
J
J
Parving
H H
HH
Deckert
T
T
D017920:Antiporters; D001692:Biological Transport; D001794:Blood Pressure; D002352:Carrier Proteins / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications; D003928:Diabetic Nephropathies / Q000150:complications*; D004910:Erythrocyte Membrane / Q000378:metabolism*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology*; D008094:Lithium / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000378:metabolism*
D017920:Antiporters; D002352:Carrier Proteins; C045885:sodium-lithium countertransporter; D008094:Lithium; D012964:Sodium