| City: |
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Mineola |
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State:
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NY |
| Zip Code: |
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11501 |
| Conditions: |
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Determining if Vitamin D Can Decrease Bone Loss and Inhibit the Decline Physical Performance in Elderly African American Women. |
| Purpose: |
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Vitamin D is a hormone that is produced when sunlight is absorbed by the skin. Vitamin D
insufficiency has been recognized as a problem in areas where sun exposure is limited,
especially in the wintertime. In addition, the more pigmented the skin is, the less capable
it is of utilizing sunlight to make vitamin D. Vitamin D plays an important role in helping
the body absorb calcium and in building strong bones. It has also been shown to improve
muscle function in the elderly. As we get older, our vitamin D levels in the blood go down
and this may increase the risk for falls and fractures. If we can improve vitamin D status
as we age, we may be able to improve muscle strength and decrease the risk of falls and
fractures.
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| Study summary: |
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The long-term goal of this project is to develop strategies for the prevention of
osteoporotic fractures in African Americans. Most intervention studies have excluded
African Americans because of the erroneous belief that osteoporosis is not a major health
problem in this population. In fact, the incidence rate of hip fracture in blacks is 50% of
the rate in whites. Since longevity is increasing in the black population, osteoporotic
fractures will become an even greater problem for this ethnic minority in the future.
Furthermore, morbidity and mortality from osteoporotic fractures is greater in blacks. The
elderly require higher intake of vitamin D to prevent bone loss resulting from secondary
hyperparathyroidism. Calcium with sufficient vitamin D supplementation may decrease
fractures in elderly white populations as a result of reduction in bone loss and falls
(improved physical performance). The only fracture intervention study to include African
Americans—the Women's Health Initiative—used an inadequate dose of vitamin D (400 IU), a
dose unlikely to achieve the vitamin D status proposed by U.S. experts: serum 25
hydroxyvitamin D [25(OH)D] concentration above 75 nmol/L. No calcium/vitamin D intervention
studies on fall prevention or physical performance have included African Americans.
As a result of increased skin pigmentation, blacks synthesize less vitamin D from sun
exposure. As a result, serum 25(OH)D levels are often in the "insufficient" range. This is
accompanied by secondary hyperparathyroidism, but adult blacks have a relative skeletal
resistance to PTH, so that they have lower bone turnover. They also have more efficient
renal conservation of calcium starting in childhood. Addition of vitamin D3 to a
calcium-sufficient African American postmenopausal population does not prevent bone loss.
The calcium/vitamin D requirements of black adults may be lower than white adults through
midlife. However, the elderly require more vitamin D to produce the higher 25(OH)D levels
required to overcome the hyperparathyroidism associated with aging. The skeleton of elderly
African Americans appears to be susceptible to the increasing parathyroid hormone levels of
old age. Bone loss accelerates and bone turnover markers increase in elderly African
Americans just as in whites. The specific aims of this project are to determine if dietary
supplementation with calcium/vitamin D will safely reduce bone loss and bone turnover and
improve physical performance in elderly African Americans. We will enroll 250 African
American women in a four-year vitamin D3 intervention trial where serum 25(OH)D will be
maintained at an optimum level above 75 nmol/L. Adequate calcium intake will be ensured.
Functional markers of vitamin D including bone density, serum PTH, and bone turnover will be
measured. The NIH Conference on Vitamin D and Health in the 21st Century, September 5-6,
2007 concluded that research in this population is a high priority. |
| Criteria: |
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Inclusion Criteria:
1. Ambulatory women older than 70 years of age. Self declared as African Americans.
2. 20 nmol/L < serum 25(OH)D level < 65 nmol/L.
3. Willingness to take study drug and participate for four years in the trial.
4. Willingness to refrain from the use of self-administered supplements during the
trial.
Exclusion Criteria:
1. Serum 25(OH)D levels ≤ 20 nmol/L or ≥ 65 nmol/L.
2. BMD total hip below - 2.5 standard deviation (using NHANES III adult young white men
and women as the point of reference) or history of osteoporotic fracture.
3. Moderate to severe fracture in one or more vertebrae by Instant Vertebral Assessment
on DXA.
4. Treatment with HRT, SERMS, calcitonin, PTH, androgens, bisphosphonates, phosphate or
anabolic steroids during 6 months prior to entry.
5. Use of systemic corticosteroids (oral or IV) within the last year at an average dose
of greater than 5 mg per day of oral prednisone or equivalent for a period of three
months or more prior to screening.
6. Hypercalcemia (serum calcium > 10.6 mg (dl) or history of primary
hyperparathyroidism.
7. History of chronic liver disease, chronic renal insufficiency, Parkinson's, metabolic
bone disease, hema-tologic tumors, rheumatologic disease requiring steroids,
malabsorption or new diagnosis or active treat-ment of cancer 12 months prior to
inclusion.
8. Use of medications that influence bone metabolism (e.g. anticonvulsants).
9. Significant deviation from normal in either: history, physical examination or
laboratory tests as evaluated by the Principle Investigator. Participants with a
history of hypercalciuria, nephrolithiasis and active sarcoidosis will also be
excluded.
10. Participation in another investigational trial 30 days prior to screening.
11. Spinal disease that affects interpretation of bone densitometry like scoliosis with a
Cobb angle greater than 15o, history of surgery at lumbosacral spine.
12. Bilateral hip replacement.
13. Currently smoking more than 10 cigarettes daily.
14. Body width on DXA > 25 cm.
15. Patients who are deemed unsafe to perform muscular function testing as evaluated by
the investigator.
---------- Study participants should live close to the study site, as this study
requires multiple visits over a four year period. |
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| Study is available at: |
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Winthrop University Hospital
Mineola, NY 11501
United States
Primary Contact:
John F. Aloia, MD
Email: Jaloia@winthrop.org
Phone: 516-663-2442
Secondary Contact:
Jane S. Greensher, R.N. CCRC
Email: Jmoore@winthrop.org
Phone: 516 663 2772 |
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If you are interested in this clinical trial please use the contact information above. If you would like to get additional information about this clinical trial please visit ClinicalTrials.gov.
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| Data Source: |
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ClinicalTrials.gov |
| Date Processed: |
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March 23, 2011 |
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