Vitamin D Retrospective Study and Role With Disease

Association of Vitamin D With Diabetes, Osteoporosis and Cardiovascular Risk

Vitamin D deficiency is associated with a heightened risk for developing type 2 diabetes, hypertension, and osteopenia/osteoporosis. Vitamin D is made in the skin when it is exposed to sunlight and it is also obtained from the diet and dietary supplements. Older people, individuals with high skin pigmentation, obese and sedentary individuals have low levels of Vitamin D because pigmentation blocks Vitamin D production in the skin, aging and physical inactivity are associated with reduced exposure to sunlight, and obesity is associated with the storage of Vitamin D in fat preventing its utilization by muscle, bone and other tissues that require its metabolic action. These conditions are also associated with heightened risk for developing type 2 diabetes, glucose intolerance, hypertension, and osteopenia/osteoporosis in older and obese individuals. This is particularly heightened in older women who tend to have increased body fat, are more physically inactive and are at high risk for central obesity and its metabolic consequences of diabetes, hypertension and osteoporosis.

Study Overview

• Status: Active, not recruiting
• Conditions: Blood Pressure; Glucose Tolerance; Hyperlipidemia; Bone Mineral Density; Vitamin D Status
• Intervention / Treatment: Other: Vitamin D

Detailed Description

The heightened prevalence of obesity in aging especially in postmenopausal women suggests that interventions to raise Vitamin D levels might be preventive of these diseases. Investigators have completed studies of the effects of weight loss and exercise interventions in approximately 400 older women and men over the last 15 years, many of whom are obese. Investigators have data on glucose tolerance, blood pressure and bone density in these studies and stored plasma in which investigators can analyze Vitamin D levels. Vitamin D may be an important risk factor for these metabolic diseases and the availability of these samples for Vitamin D analysis will allow investigators to perform a cross-sectional study to address relationships of Vitamin D levels to glucose intolerance and diabetes, hypertension/blood pressure status, bone mineral density, the degree of obesity, and physical activity status measured as maximal aerobic capacity and accelerometry in these older men and women.

The results of this study have the potential to impact clinical practice in the prevention and treatment of diabetes, hypertension, and osteopenia/osteoporosis. This would circumvent the current dilemma for prevention of these chronic diseases through treatment of obesity, as these data would provide immediate prospects for changing the recommended doses of Vitamin D beneficial for reducing risk for these diseases.

The purpose of this study is to 1) determine the prevalence of Vitamin D deficiency in obese, older men and postmenopausal women and 2) the association of Vitamin D levels to glucose tolerance, blood pressure, bone mineral density, and hyperlipidemia, as well as association with Vitamin D receptor gene polymorphisms affecting metabolic responses to Vitamin D.

• Study Type: Observational
• Enrollment (Actual): 362

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • Baltimore VAMC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 45 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

obese, older men and postmenopausal women

Description

Inclusion Criteria: 45-85 years of age

Exclusion Criteria: none

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Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Vitamin D; Specimen analysis	Other: Vitamin D; N/A, frozen specimen study

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Vitamin D	Vitamin D level ng/dl	Day 1

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
IGF-1	Insulin like growth factor	Day 1
IGF binding proteins	Insulin Growth Factor Binding protein levels	Day 1
PTH	Parathyroid Hormone levels	Day 1

Collaborators and Investigators

• Sponsor: Baltimore VA Medical Center
• Investigators: Principal Investigator: Alice S Ryan, PhD, Baltimore VAMC

Publications and helpful links

General Publications

• Sorkin JD, Vasaitis TS, Streeten E, Ryan AS, Goldberg AP. Evidence for threshold effects of 25-hydroxyvitamin D on glucose tolerance and insulin resistance in black and white obese postmenopausal women. J Nutr. 2014 May;144(5):734-42. doi: 10.3945/jn.114.190660. Epub 2014 Apr 9.

Study record dates

Study Major Dates

• Study Start: November 1, 2009
• Primary Completion (Anticipated): November 1, 2021
• Study Completion (Anticipated): December 1, 2022

Study Registration Dates

• First Submitted: February 21, 2013
• First Submitted That Met QC Criteria: February 22, 2013
• First Posted (Estimate): February 25, 2013

Study Record Updates

• Last Update Posted (Actual): July 20, 2021
• Last Update Submitted That Met QC Criteria: July 19, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Keywords: Diabetes; Vitamin D; Osteoporosis; Cardiovascular Risk
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Dyslipidemias; Hyperlipidemias; Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Vitamin D
• Other Study ID Numbers: 43973

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO