Platelet Na + /H + exchanger activity in patients with coronary heart disease confirmed by selective arteriography and the disturbances of carbohydrate metabolism

Abstract

INTRODUCTION. Enhanced activity of Na⁺/H⁺ exchangers (NHE, sodium/proton exchanger) has been previously described in patients with arterial hypertension, poorly controlled type 1 and type 2 diabetes and nephropathy. There were also clinical trials with NHE1 inhibitors in patients with acute coronary syndromes. The aim of our study was the estimation of platelet Na⁺/H⁺ exchanger activity and selected risk factors in patients referred for coronary angiography, dependent on the disturbances of carbohydrate metabolism and atherosclerotic lesions.
MATERIAL AND METHODS. Platelet Na⁺/H⁺ exchanger activity was measured in platelet rich plasma, using an optical swelling assay, in 55 consecutive patients (7 with impaired glucose tolerance [IGT] and 14 with type 2 diabetes) with positive exercise test (mean age 57.3 ± 6.6 years) and in 32 healthy subjects (mean age 48.4 ± 9.0 years).
RESULTS. Na⁺/H⁺ exchanger activity was markedly increased in patients with coronary heart disease in comparison to the controls (4.36 ± 0.90 × 10^-3 × s^-1 vs 3.18 ± 0.55 × 10^-3 × s^-1, p = 0.000001). However, there was no significant differences between subjects with 1-, 2- and 3-vessel disease, nor with and without arterial hypertension (4.48 ± 0.92 × 10^-3 × s^-1 vs 4.34 ± 0.88 × 10^-3 × s^-1), as well as between patients with normal glucose tolerance, IGT and type 2 diabetes, however the mean values in each group were significantly higher than in the controls. Na⁺/H⁺ exchanger activity correlated with BMI (r = 0.30, p = 0.047).
CONCLUSIONS. Our study suggests enhanced activity of platelet Na⁺/H⁺ exchanger in patients with coronary heart disease, but the problem needs further investigations.