Effects of reduced sodium intake on hypertension control in older individuals - Results from the trial of nonpharmacologic interventions in the elderly (TONE)

Background: Few trials have evaluated the effects of reduced sodium intake in older individuals, and no trial has examined the effects in relevant sub groups such as African Americans. Patients And Methods: The effects of sodium reduction on blood pressure (BP ) and hypertension control were evaluated in 681 patients with hypertension , aged 60 to 80 years, randomly assigned to a reduced sodium intervention o r control group. Participants (47% women, 23% African Americans) had systol ic BP less than 145 mm Hg and diastolic BP less than 85 mm Hg while taking 1 anti-hypertensive medication. Three months after the start of interventio n, medication was withdrawn. The primary end point was occurrence of an ave rage systolic BP of 150 mm Hg or more, an average diastolic BP of 90 mm Hg or more, the resumption of medication, or a cardiovascular event during fol low-up (mean, 27.8 months). Results: Compared with control, mean urinary sodium excretion was 40 mmol/d less in the reduced sodium intervention group (P<.001); significant reduct ions in sodium excretion occurred in subgroups defined by sex, race, age, a nd obesity. Prior to medication withdrawal, mean reductions in systolic and diastolic BPs from the reduced sodium intervention, net of control, were 4 .3 mm Hg (P<.001) and 2.0 mm Hg (P=.001). During followup, an end point occ urred in 59% of reduced sodium and 73% of control group participants (relat ive hazard ratio=0.68, P<.001). In African Americans, the correspending rel ative hazard ratio was 0.56 (P=.005); results were similar in other subgrou ps. In dose-response analyses, end points were progressively less frequent with greater sodium reduction (P for trend=.002). Conclusion: A reduced sodium intake is a broadly effective, nonpharmacologi c therapy that can lower BP and control hypertension in older individuals.