Response of diastolic blood pressure to long-term sodium restriction is posture related

Eighty-five subjects, aged 31–55 years, suffering from uncomplicated essential hypertension and receiving no regular medication were randomized to sodium restriction and control groups. Systolic (SBP) and diastolic (DBP) blood pressure were measured during an orthostatic test at baseline and after 6 months sodium restriction. The mean daily sodium excretion of 43 treated subjects decreased from 193±91 mmol to 95±70 mmol (p 10 mmHg, n=17), indeterminate (DBP decrease 5–10 mmHg, n=18) and sodium-resistant (DBP decrease < 5 mmHg, n=8) subgroups. At 6 months the level of DBP in the supine position was lower than at baseline in both sensitive and resistant subgroups, whereas in the standing position a lower DBP than at baseline was seen only in the sodium-sensitive subgroup. The magnitude of the su...