Vitamin D Retrospective Study and Role With Disease

NCT ID: NCT01798030

Last Updated: 2021-07-20

Basic Information

• Recruitment Status: UNKNOWN
• Total Enrollment: 362 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2009-11-30
• Study Completion Date: 2022-12-31

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.

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.

Conditions

Vitamin D Status; Glucose Tolerance; Blood Pressure; Bone Mineral Density; Hyperlipidemia

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: RETROSPECTIVE

Study Groups

Vitamin D

Specimen analysis

Vitamin D

Intervention Type: OTHER

N/A, frozen specimen study

Interventions

Vitamin D

N/A, frozen specimen study

Intervention Type: OTHER

Eligibility Criteria

Exclusion Criteria

-

• Minimum Eligible Age: 45 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Baltimore VA Medical Center

FED

Sponsor Role: lead

Responsible Party

Alice S. Ryan, PhD

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Alice S Ryan, PhD

Role: PRINCIPAL_INVESTIGATOR

Baltimore VAMC

Locations

Baltimore VAMC

Baltimore, Maryland, United States

Countries

United States

References

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.

Reference Type: DERIVED

PMID: 24717362 (View on PubMed)

Other Identifiers

43973

Identifier Type: -

Identifier Source: org_study_id