Erythrocyte Na(+)-K(+)-ATPase activity, metabolic control, and neuropathy in IDDM patients.
OBJECTIVE
To study the relationship among red blood cell Na(+)-K(+)-ATPase activity, metabolic control, and diabetic neuropathy.


METHODS
Na(+)-K(+)-ATPase activity has been measured in the red cell membrane of 43 long-standing IDDM patients (duration of diabetes 17.5 +/- 2 years, mean +/- SE), with 20 of the patients presenting with peripheral neuropathy. There were 23 healthy subjects serving as the control group.


RESULTS
Na(+)-K(+)-ATPase activity was significantly lower in diabetic patients than in healthy subjects (236.5 +/- 7.5 vs. 294 +/- 10 nmol P1 . mg protein-1 . h-1, P < 0.05). Among diabetic patients, Na+/K(+)-ATPase activity was not dependent on the degree of diabetic control, nor was it correlated with either fasting blood glucose (r = 0.16, NS) or HbA1 (r = 0.01, NS). Na(+)-K(+)-ATPase activity was lower in patients with neuropathy than in those without it (212 +/- 8.5 vs. 261 +/- 6.6, P < 0.05). Furthermore, in a subgroup of 20 patients, a positive correlation was observed between erythrocyte Na(+)-K(+)-ATPase activity and nerve conduction velocity in the peroneal (r = 0.558, P < 0.02) and tibial nerve (r = 0.528, P < 0.05).


CONCLUSIONS
These results suggest that diabetes-induced Na(+)-K(+)-ATPase activity dysfunction could be implicated in the pathogenesis of human diabetic neuropathy and the electrophysiological abnormalities observed in these patients.
Raccah
D
D
Diabetes Department, University Hospital Timone, Marseille, France.
Fabreguetts
C
C
Azulay
J P
JP
Vague
P
P
D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000201:enzymology / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000097:blood* / Q000503:physiopathology; D004910:Erythrocyte Membrane / Q000201:enzymology*; D005071:Evoked Potentials; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D010543:Peroneal Nerve / Q000503:physiopathology; D012016:Reference Values; D012044:Regression Analysis; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*; D013497:Sural Nerve / Q000503:physiopathology; D013979:Tibial Nerve / Q000503:physiopathology
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D000254:Sodium-Potassium-Exchanging ATPase