Vitamin D Retrospective Study and Role With Disease

• ClinicalTrials.gov Identifier: NCT01798030
• Recruitment Status: Active, not recruiting
• First Posted: February 25, 2013
• Last Update Posted: May 18, 2020
• Sponsor: Baltimore VA Medical Center
• Information provided by (Responsible Party): Alice S. Ryan, PhD, Baltimore VA Medical Center

Study Description

Brief Summary:

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.

Condition or disease	Intervention/treatment
Vitamin D Status; Glucose Tolerance; Blood Pressure; Bone Mineral Density; Hyperlipidemia	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 Design

• Study Type: Observational
• Actual Enrollment: 362 participants
• Observational Model: Other
• Time Perspective: Retrospective
• Official Title: Association of Vitamin D With Diabetes, Osteoporosis and Cardiovascular Risk
• Study Start Date: November 2009
• Estimated Primary Completion Date: November 2020
• Estimated Study Completion Date: December 2020

Groups and Cohorts

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

Outcome Measures

Primary Outcome Measures :

1. Vitamin D [ Time Frame: Day 1 ]
   Vitamin D level ng/dl

Other Outcome Measures:

1. IGF-1 [ Time Frame: Day 1 ]
   Insulin like growth factor
2. IGF binding proteins [ Time Frame: Day 1 ]
   Insulin Growth Factor Binding protein levels
3. PTH [ Time Frame: Day 1 ]
   Parathyroid Hormone levels

Biospecimen Retention:   Samples With DNA

Vitamin D, IGF-1, and PTH levels will be measured in coded plasma samples belonging to the PI and collaborating Investigators within the GRECC that are stored in our freezers (from previously approved studies: HP-00040261,HP-00040975, HP-00041166 and HP-00041199) . The Nutrition Obesity research center genetics core will determine Vitamin D receptor polymorphisms on de-identified samples. No clinical information will accompany the samples.

Eligibility Criteria

• Ages Eligible for Study: 45 Years to 85 Years (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes
• Sampling Method: Non-Probability Sample

Study Population

obese, older men and postmenopausal women

Criteria

Inclusion Criteria: 45-85 years of age

Exclusion Criteria: none

-

Contacts and Locations

Locations

United States, Maryland

Baltimore VAMC

Baltimore, Maryland, United States, 21201

Sponsors and Collaborators

Baltimore VA Medical Center

Investigators

• Principal Investigator: Alice S Ryan, PhD; Baltimore VAMC

More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

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.

• Responsible Party: Alice S. Ryan, PhD, Professor, Baltimore VA Medical Center
• ClinicalTrials.gov Identifier: NCT01798030
• Other Study ID Numbers: 43973
• First Posted: February 25, 2013
• Last Update Posted: May 18, 2020
• Last Verified: May 2020

Individual Participant Data (IPD) Sharing Statement:

• Plan to Share IPD: No

Keywords provided by Alice S. Ryan, PhD, Baltimore VA Medical Center:

Vitamin D; Diabetes; Osteoporosis; Cardiovascular Risk

Additional relevant MeSH terms:

Hyperlipidemias; Metabolic Diseases; Dyslipidemias; Lipid Metabolism Disorders; Vitamin D; Vitamins; Micronutrients; Nutrients; Growth Substances; Physiological Effects of Drugs; Bone Density Conservation Agents