INSULIN RESISTANCE AND ENDOGENOUS DIGOXIN-LIKE FACTOR IN OBESE HYPERTENSIVE PATIENTS WITH GLUCOSE-INTOLERANCE

Hypertensive obese subjects with glucose intolerance have hyperinsulin aemia, insulin resistance and intracellular cation imbalance resulting in increased sodium content. The aim of our study was to assess in th ese patients plasma levels of endogenous digoxin-like factor (EDLF), a n inhibitor of the sodium-pump mechanism. We studied 14 hypertensive a nd 12 normotensive subjects with obesity and glucose intolerance for f asting blood glucose, and plasma insulin, C-peptide and EDLF levels: t he two groups were matched for age and BMI and were studied after a 2- week wash-out period from hypotensive drugs. Compared with normotensiv es, hypertensive subjects had higher plasma insulin levels, a greater immunoreactive insulin/C-peptide ratio, a lower glucose/insulin ratio and higher plasma EDLF levels. Our results confirm that among obese pe ople with glucose intolerance, hypertensives are more hyperinsulinaemi c and insulin-resistant than normotensives and indicate that the intra cellular cation imbalance in these patients may be attributable, at le ast in part, to EDLF.