Clinical trial NCT00876928: Vitamin D in Minorities With Prediabetes
Official title: Effect of Vitamin D Supplementation on Pre-Diabetes in a Minority Population
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Pre-diabetes
Keywords: pre-diabetes
minorities
oral glucose tolerance test
disposition index
insulin secretion
insulin sensitivity
diabetes
Lead sponsor: Charles Drew University of Medicine and Science
Sponsor class: OTHER
Collaborators: name: American Diabetes Association
First posted: 2009-04-07
Enrollment: 117
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Vitamin D supplementation in minority subjects with both pre-diabetes and low vitamin D levels will delay the development of diabetes.

Detailed description: Low vitamin D levels 1) are associated with abnormalities in insulin secretion and insulin action, 2) predict the development of diabetes in those without diabetes, and 3) are more common in people with diabetes. Minority populations (African-Americans and Latinos) are more likely to have both low levels of vitamin D and diabetes. This study will identify minority individuals who are at increased risk for diabetes (those with central obesity, family history of diabetes in first degree relatives and either with hypertension or being treated for hypertension), and determine if they have both pre-diabetes, ie, impaired fasting glucose and/or impaired glucose tolerance, and low levels of vitamin D. Those that have both will be randomized to either high doses of vitamin D or placebo and insulin secretion and action as well as changes in the oral glucose tolerance test (reversion to normal, maintenance of pre-diabetes or development of diabetes) will be monitored at 3 month intervals for one year. This study will test the hypothesis that the increased amount of diabetes in minority populations may be due in part to low levels of vitamin D and whether supplementing this vitamin may delay the development of diabetes.

Eligibility criteria: Inclusion Criteria:

1. Age greater than 40.
2. Impaired fasting glucose (FPG level greater than 100 and less than 126 mg/dl); and/or
3. Impaired glucose tolerance (2-h plasma glucose concentration after 75 gram glucose load greater than 140 and less than 200 mg/dl)
4. Serum 25-OHD less than 30 ng/ml
5. Able and willing to provide informed consent

Exclusion Criteria:

1. FPG greater than 126 mg/dl or 2-hour-OGTT plasma glucose greater than 200 mg/dl
2. Major psychiatric disorder on medication (excluding successfully treated depression)
3. Diagnosed diabetes mellitus
4. HIV/AIDS
5. Major hematological, hepatic (AST/ALT levels greater than or equal to 2 times normal) or renal eGFR less than 60 ml/min) disorder
6. History of carcinoma, except skin basal cell or squamous cell skin carcinomas
7. Heart failure, unstable angina or history of a myocardial infarction
8. Alcohol or substance abuse
9. Current treatment with glucocorticoids
10. Current treatment with diabetes medications, including metformin
11. Cushing's syndrome
12. Primary hyperparathyroidism
13. Nephrolithiasis
14. Pregnancy or breast-feeding
15. Regular visits to a tanning salon (unlikely in this minority population)

Primary outcomes:
measure: Percent of Subjects Who Develop Diabetes
timeFrame: one year
Secondary outcomes:
measure: Disposition Index
timeFrame: Baseline, 3, 6, 9, 12 months
Other outcomes:
Locations:
city: Los Angeles
country: United States
facility: Charles Drew University
state: California
Study officials:
affiliation: Charles Drew University
name: Mayer B. Davidson, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Sinha-Hikim I, Duran P, Shen R, Lee M, Friedman TC, Davidson MB. Effect of long term vitamin D supplementation on biomarkers of inflammation in Latino and African-American subjects with pre-diabetes and hypovitaminosis D. Horm Metab Res. 2015 Apr;47(4):280-3. doi: 10.1055/s-0034-1383652. Epub 2014 Jul 10.
citation: Davidson MB, Duran P, Lee ML, Friedman TC. High-dose vitamin D supplementation in people with prediabetes and hypovitaminosis D. Diabetes Care. 2013 Feb;36(2):260-6. doi: 10.2337/dc12-1204. Epub 2012 Oct 1.