Vitamin D and Physical Function in Older Adults

Role of Vitamin D Status on Physical Function and Falls in Adults of Advanced Age

Projections from NHANES III indicate that approximately 12,000,000 U.S. adults ≥ 60 years of age have vitamin D insufficiency (serum 25(OH)D < 50 nmol/L). A growing body of evidence suggests that vitamin D status may be important in biologic processes involved in the maintenance of physical function. To test the hypothesis that vitamin D insufficiency is associated with poorer muscle strength and physical performance, we propose to evaluate the role of vitamin D status (serum 25(OH)D) on physical function and falls in the CHS All Stars cohort, a population of advanced age. The specific aims are as follows:

Specific Aim 1. To describe the prevalence and correlates of vitamin D insufficiency in adults of advanced age.

Specific Aim 2. To examine the cross-sectional association between vitamin D status and muscle strength (leg and grip strength), physical performance (3 m/15 ft walk time, repeated chair stands, and standing balance), self-reported physical function (mobility, ADL and IADL disability), and falls.

Specific Aim 3. To examine the longitudinal association between vitamin D status at baseline and incident disability (mobility, ADL and IADL disability) over 3 years of follow-up.

Research Hypotheses: Low vitamin D status (25(OH)D < 50 nmol/L) will be associated with (a) lower levels of muscle strength and physical performance; (b) higher levels of self-reported limitations in physical function and falls; and (c) greater odds of incident disability.

Study Overview

• Status: Completed
• Conditions: Physical Function; Vitamin D

• Study Type: Observational
• Enrollment (Actual): 1100

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 79 years and older (OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Cardiovascular Health Study (CHS), is a longitudinal, observational, population-based study of the onset, progression, and course of heart disease and stroke in the elderly which began in 1988. We are only examining those that participated in the the CHS All Stars which is from the same cohort of people who were still alive in 2005 when enrollment began. We approached everyone who was in the CHS study and asked them to participate in the CHS All Stars study. Blood samples were collected at the year 18 visit and analyzed for serum 25(OH)D.

Description

Inclusion Criteria:

• Participant in the main CHS study

Exclusion Criteria:

• Not willing to give consent

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

CHS All Stars; CHS All Stars is an ancillary study of the Cardiovascular Health Study (CHS), a longitudinal, observational, population-based study of the onset, progression, and course of heart disease and stroke in the elderly which began in 1988. The All Stars study reexamined the survivors of CHS to determine the likelihood of maintaining function later in life. A focus was to determine whether age-related biological factors are long-term predicators of functional aging which was assessed through a follow-up exam (Yr 18 visit conducted in 2005-06, n=1674 older adults, mean age =84 years) and 3 yrs of subsequent 6 month interval phone contacts. Vitamin D status (serum 25(OH)D and PTH) is being assessed in all CHS All Stars participants who provided a blood sample at the Yr 18 visit (n~1100).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To examine the association between vitamin D status and muscle strength (leg, grip strength), physical performance (3m/15 ft walk time, repeated chair stands, and balance), self-reported physical function (mobility, ADL and IADL disability), and falls.	At the year 18 visit of the CHS study
To examine the longitudinal association between vitamin D status at baseline and incident disability (mobility, ADL and IADL disability) over 3 years of follow-up.	Years 18 - 21 of CHS Study

Secondary Outcome Measures

Outcome Measure	Time Frame
To describe the prevalence and correlates of vitamin D insufficiency in adults of advanced age.	Year 18 of CHS study

Collaborators and Investigators

• Sponsor: Wake Forest University Health Sciences
• Collaborators: Merck Sharp & Dohme LLC

Publications and helpful links

Helpful Links

• CHS Study Home page

Study record dates

Study Major Dates

• Study Start: April 1, 2008
• Primary Completion (ACTUAL): February 1, 2011
• Study Completion (ACTUAL): February 1, 2011

Study Registration Dates

• First Submitted: July 2, 2008
• First Submitted That Met QC Criteria: July 2, 2008
• First Posted (ESTIMATE): July 8, 2008

Study Record Updates

• Last Update Posted (ACTUAL): July 6, 2018
• Last Update Submitted That Met QC Criteria: July 3, 2018
• Last Verified: July 1, 2018

More Information

Terms related to this study

• Keywords: Vitamin D; Physical Function; Aging; Falls; CHS
• Other Study ID Numbers: IRB00005739