The Effect of Sodium Reduction on Blood Pressure and Physical Function in Older Adults

The Effect of Sodium Reduction on Blood Pressure and Physical Function in Older Adults

This study will examine the effects of low sodium meal plan on seated blood pressure in older adults from a community-based, congregate senior living facility.

Hypertension in older adults is a known contributor to both cardiovascular disease and falls. The Centers of Disease Control advocates for low sodium, senior meal plans as a strategy to lower blood pressure (BP). However, sodium is recommended to treat orthostatic hypotension (OH), a risk factor of falls. The long-term effects of low sodium intake on physical function are largely unknown in older adults.

The objective of this proposed pilot study is to determine the feasibility of an individual-level, randomized feeding study that examines the impact of sodium reduction on BP regulation among 40 semi-independent, older adults aged 60 and above.

Primary Aim 1: To determine the effects of a low sodium (<0.9 mg per kcal of energy intake), 2-week meal plan compared with a usual meal plan (average sodium ~2 mg per kcal of energy intake) on seated BP among independently living older adults.

Hypothesis Aim 1: Compared with the usual meal plan, a reduced sodium meal plan will lower seated BP in older adults after 2 weeks.

Feasibility Aim 1: To evaluate the recruitment experience, meal cost, meal delivery logistics, and compliance with and tolerability of the meal plan (urine sodium and palatability questionnaires).

Feasibility Aim 2: To determine effect size (variance) of secondary outcomes: standing BP, OH (standing minus seated BP), orthostatic symptoms, and a timed up and go test (TUG).

Eligible participants will be randomized to low versus usual sodium meal plans for two weeks. Assessments will be made at the in-person baseline visit, one week telephonic interview and 2 week in person follow-up visit.

The primary outcome is seated BP and secondary outcomes include orthostatic hypertension and Timed Up and Go (TUG) tests. Both primary and secondary outcomes will be measured twice: (1) before the study begins (baseline), and (2) after 2 week period. Patient-reported outcomes, dietary compliance, and urine electrolytes will be assessed as well.

Intent-to-treat analysis will be conducted for all endpoints.

Inclusion Criteria:

• Resident at Jack Satter House in Revere
• Age >= 60 years
• Resting systolic blood pressure 100-149 mm Hg and diastolic blood pressure <100 mm Hg
• Stable BP medications (no recent or intended changes)

Exclusion Criteria:

• Cognitive Impairment (Montreal Cognitive Assessment test <18)
• Unstable blood pressure medications in the past 2 months
• Terminal or mental illness
• Severe allergies to common foods
• Unwillingness to comply with the diet
• Physical inability to do a timed up and go test
• Active kidney dialysis or history of kidney transplant