Diet, ExerCIse and carDiovascular hEalth (DECIDE) - Salt Reduction Strategies for the Elderly in Nursing Homes in China

Diet, Exercise and Cardiovascular Health - Effect of Salt Substitute and Stepwise Salt Supply Control in Reducing Blood Pressure in the Elderly in Nursing Homes in China: a Factorial Cluster-randomized Controlled Trial

Sponsors

Lead Sponsor: Peking University

Collaborator: Changzhi Medical College
Xian Jiaotong University
Hohhot Center for Disease Control and Prevention
Yangcheng Ophthalmology Hospital

Source Peking University
Brief Summary

The DECIDE - Salt in Elderly (Diet, ExerCIse and carDiovascular hEalth - Salt Reduction Strategies for the Elderly in Nursing Homes in China) is to evaluate the effects, safety and cost-effectiveness of salt substitution (SS) and stepwise salt supply control (SSSC) in reducing blood pressure in Chinese elderly in nursing homes. The study will recruit over 1080 old people from 48 nursing homes in northern China. The 48 nursing homes will be randomised into the following 4 groups.

1. salt substitute (SS) and stepwise salt supply control (SSSC);

2. SS only;

3. SSSC only; and

4. no SS and no SSSC (control).

The intervention will last over 2 years. The randomization will be conducted centrally after the baseline survey completed. Primary outcome will be the change in systolic blood pressure. The secondary outcomes include: the changes in diastolic blood pressure, 24hr urinary sodium, potassium and microalbumin, and incidence of hyperkalemia and hyponatremia and cardiovascular events, death and incremental cost-effectiveness ratio.

Detailed Description

The DECIDE - Salt in Elderly (Diet, ExerCIse and carDiovascular hEalth - Salt Reduction Strategies for the Elderly in Nursing Homes in China) is a study in the DECIDE project, which includes five studies. The others are DECIDE - Diet, DECIDE - Exercise, DECIDE - Obesity in Children, and DECIDE - Smart Living. The DECIDE - Salt in Elderly study is to evaluate the effects, safety and cost-effectiveness of salt substitution (SS) and kitchen-based stepwise salt supply control (SSSC) in reducing blood pressure in Chinese elderly in nursing homes. Specifically, the study aims include:

1. to test if a stepwise salt supply control strategy could significantly reduce systolic blood pressure among elderly living in nursing homes;

2. to test if replacing regular salt with the market available salt substitute could significantly reduce systolic blood pressure among elderly living in nursing homes; and

3. to test if the joint effect of the two strategies is larger than that from one of each.

The corresponding null hypotheses that will be tested are:

1. the mean systolic blood pressure of elderly residents in nursing homes that are supplied with SS is equal to the mean systolic blood pressure of elderly residents in nursing homes that are supplied with regular salt;

2. the mean systolic blood pressure of elderly residents in nursing homes that apply SSSC is equal to the mean systolic blood pressure of elderly residents in nursing homes that do not apply SSSC;

3. There is no interaction between the two interventions above.

The study will recruit over 1080 old people from 48 nursing homes in northern China, where the mean salt intake is generally higher than 12 g/day. A 2x2 factorial cluster-randomized trial will be used to test two independent salt reduction strategies: 1) using salt substitute to replace the regular salt in the kitchen of nursing homes; and 2) training the nursing manager to control/reduce, step by step, the amount of salt supplied to the kitchen of nursing homes. The 48 nursing homes will be randomized to the following 4 groups.

1. salt substitute (SS) and stepwise salt supply control (SSSC);

2. SS only;

3. SSSC only; and

4. no SS and no SSSC (control).

A brief health education on salt and health will be applied to all four groups. The salt substitute (NaCl 62.5% and KCl 25%) will be centrally provided. And the Train-the-trainers model will be used to train the nursing home managers how to implement the SSSC.

The intervention will last over 2 years. The baseline examination including three blood pressure measurements and one 24-hr urine collection will be conducted for all participants. Fasting blood samples will be drawn for measurement of serum potassium and detect hyperkalemia and hyponatremia.

The randomization will be conducted centrally by the study coordinating center at Peking University Clinical Research Institute, after the baseline survey completed.

All participants will be followed up for blood pressure measurements at 6, 12, 18 and 24 months, for serum potassium at 12 and 24 months, and for 24-hr urine collection at 24 months.

Study outcomes:

Primary outcome: The change in systolic blood pressure from the baseline to 24 months

Secondary outcomes: The incidence of hyperkalemia and hyponatremia from the baseline to 24 months. The change in 24-hr urinary sodium, potassium and microalbumin from the baseline to 24 months. The change in diastolic blood pressure from the baseline to 24 months. The change in ocular fundus. The change in incremental cost-effectiveness ratio (ICER) from the baseline to 24 months. The incidence of cardiovascular events and death from the baseline to 24 months.

Power analysis:

On the assumptions of a 20% dropout rate, an intraclass correlation of 0.02, the number of clusters of 48 and at least 20 elderly people in each nursing home, and an α value of 0.05, the study to detect a mean 3.0 mmHg reduction in systolic blood pressure (SD, 18 mm Hg) between the intervention groups would have a power of 0.81. To detect a 4.0 mmHg reduction in systolic blood pressure (SD, 18 mm Hg), the power of the same sample size would be 0.96.

Statistical analysis: Investigators will follow the intention-to-treat principle to analyze both primary and secondary outcomes in the comparison between intervention and control.

Ethical considerations:

The study will be submitted to and approved by the Peking University IRB, which has the full accreditation from AAHRRP. The study salt substitute is the product available on Chinese market and has been approved manufactured according to the product standards issued by the ministry of health. The SSSC approach will take every step for 3 months and the biggest step of salt reduction will be just 10% of the original amount of use. And the study will ensure an interview will be conducted to collect the feedback before every next step will take place. The SSSC intervention will stop at any time that elderly people feel unlike the foods.

Overall Status Active, not recruiting
Start Date September 29, 2017
Completion Date April 30, 2022
Primary Completion Date April 30, 2020
Phase N/A
Study Type Interventional
Primary Outcome
Measure Time Frame
The change in systolic blood pressure baseline and 24-month follow-up
Secondary Outcome
Measure Time Frame
The incidence of hyperkalemia and hyponatremia throughout 24 months of follow-up
The change in 24-hour urinary sodium and potassium baseline and 24-month follow-up
The change in 24-hour urinary microalbumin baseline and 24-month follow-up
The change in diastolic blood pressure baseline and 24-month follow-up
The change in ICER baseline and 24-month follow-up
Cardiovascular events throughout 24 months of follow-up
Death throughout 24 months of follow-up
Enrollment 1080
Condition
Intervention

Intervention Type: Other

Intervention Name: SS

Description: Replace regular salt with market available potassium-enriched salt substitute in kitchens of nursing homes.

Other Name: Salt substitution

Intervention Type: Other

Intervention Name: SSSC

Description: A stepwise approach to reduce salt used in the kitchen of nursing homes by controlling the supply of salt.

Other Name: Stepwise salt supply control

Eligibility

Criteria:

Eligibility of nursing homes:

- To be eligible, the nursing home must has not participated in any salt reduction or other intervention trials, has at least 20 residents and has agreed to participate in the study.

Eligibility of individual elderly:

Inclusion Criteria:

- Living in the nursing home permanently or expectedly for the coming two years

- Life expectancy over six months.

- Provide written informed content.

Exclusion Criteria:

- No.

Gender: All

Minimum Age: N/A

Maximum Age: N/A

Healthy Volunteers: No

Overall Official
Last Name Role Affiliation
Yangfeng Wu, PhD Principal Investigator Peking University
Location
Facility: Mishan Nursing Home
Location Countries

China

Verification Date

September 2019

Responsible Party

Type: Principal Investigator

Investigator Affiliation: Peking University

Investigator Full Name: Yangfeng Wu

Investigator Title: Prof of Epidemiology and Sciences in Clincial Research

Has Expanded Access No
Number Of Arms 4
Arm Group

Label: SS+SSSC

Type: Experimental

Description: Salt substitute plus stepwise salt supply control

Label: SS only

Type: Experimental

Description: Salt substitute only

Label: SSSC only

Type: Experimental

Description: Stepwise salt supply control only

Label: control

Type: No Intervention

Description: No salt substitute and no stepwise salt supply control

Acronym DECIDE-Salt
Patient Data No
Study Design Info

Allocation: Randomized

Intervention Model: Parallel Assignment

Primary Purpose: Prevention

Masking: Single (Outcomes Assessor)

Source: ClinicalTrials.gov