Exercise-loaded blood pressure and Li-Na countertransport system in the erythrocyte membrane as predictors of mild essential hypertension prognosis.

SUMMARY 1. The blood pressure response to exercise loading, Na concentration in the erythrocyte and Li–Na countertransport (Li–Na CT) system in the erythrocyte membrane in 40 male volunteers and 98 patients with mild essential hypertension were investigated. Subjects were divided into a juvenile group ( 36 years and <65 years) group. Exercise-loaded blood pressure in patients with mild essential hypertension was followed up for more than 5 years. 2. Systolic blood pressure (SBP) at 6 min during exercise loading was significantly higher in the mild hypertension group compared with the control group. 3. Patients with high SBP at exercise loading in the mild hypertension group transferred more often to the moderate hypertension group within 5 years. 4. No difference in the haemodynamic parameter at rest was noted in the transferred group for moderate hypertension and the non-transferred group. 5. A higher blood pressure response to noradrenaline was noted in the transferred group compared with the non-transferred group of the juvenile group. 6. High Na concentration in the erythrocyte and acceleration of the Li–Na CT system in the erythrocyte membrane were noted in the mild hypertension group compared with the volunteer group. 7. A correlation between SBP at exercise loading and Li-Na CT system in the erythrocyte membrane was noted. This correlation was strongly noted in subjects less than 50 years old. 8. From these results it was concluded that SBP at exercise loading and Li–Na CT system in the erythrocyte membrane are useful as indicators for the prognosis of mild essential hypertension.