Plasma neuropeptide Y during dynamic exercise in patients with essential hypertension

The aim or the study was to assess plasma neuropeptide Y immunoreactivity concentration (NPY-ir) during dynamic exercise in pts with different stages of essential hypertension (ESH). We studied 25 males aged 29.4 +/- 6.3 yrs with established ESH (ESH) and 12 healthy males aged 27.3 +/- 5.1 yrs (C). Plasma concentrations of NPY-ir, NA, A, BP were measured before treadmill test, in the last minute of two six-min. work loads corresponding to 60% and 80% of maximal individual load and 30 min. after cessation of exercise. Plasma NPY-ir was evaluated with RIA, NA and A with REA. Gradual exercise resulted in an increase of NPY-ir in ESH (from 14.4 +/- 5.8 to 18.1 +/- 6.4 and 20.7 +/- 8.1 fmol/ml p = 0.036, p = 0.02) and in C (from 11.7 +/- 4.6 to 13.4 +/- 5.0 and 15.2 +/- 5.9 fmol/ml, p < 0.01). Likewise plasma NA and A increased in both groups. Plasma NPY-ir during exercise was significantly higher in ESH than in C (p = 0.041 and p = 0.047) while no such differences were observed in plasma NA and A. According to the left ventricle mass index (LVMI) ESH was divided into two subgroups: with left ventricular hypertrophy (LVH+) n = 10, LVMI = 159.7 +/- 7.7 g/m2 and without the hypertrophy (LVH-) n = 15 LVMI = 112.3 +/- 19.2g/m2. LVH- presented significant increase in plasma NPY-ir during exercise (from 14.7 +/- 5.7 to 18.2 +/- 6.5, 22.8 +/- 8.3 fmol/ml p < 0.01), while no changes in LVH+ were observed (from 14.1 +/- 5.8 to 17.8 +/- 6.0 and 17.8 +/- 6.7 fmol/ml, ns). LVH+ were older than LVH- (33.4 +/- 7.1 yrs vs 26.7 +/- 4.2 p = 0.04), but no correlation between age and plasma NPY-ir was noticed. No differences in plasma NA and A were present between these subgroups.

Patients at different stages of essential hypertension display various patterns of sympatho-adrenal activation during dynamic exercise.