Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT01798030 |
| Other study ID # |
43973 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
November 2009 |
| Est. completion date |
December 2022 |
Study information
| Verified date |
July 2021 |
| Source |
Baltimore VA Medical Center |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial 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.
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.
