Effects of long term supplementation of vitamin D on inflammation, cytokines, thrombosis and IGF-1 levels in minority subjects with pre-diabetes and hypovitaminosis D

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 257-280-Disorders of Vitamin D Metabolism & Action
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-268
Indrani Sinha-Hikim*1, Petra Duran2, Ruoquing Shen3, Martin Lee4, Theodore C Friedman1 and Mayer B Davidson1
1David Geffen School of Medicine, UCLA, 2Charles Drew University of Medicine and Science, 3Charles R. Drew University of Medicine and Science, Los Angeles, CA, 4Charles Drew University/ David Geffen School of Medicine, UCLA
Background: Vitamin D levels are lower in people with pre-diabetes and diabetes and diabetes is associated with increased inflammation and thrombotic tendencies. In-vitro studies support the involvement of vitamin D in modulating the inflammatory cytokine responses. Low vitamin D levels and low growth hormone levels are both found in obesity and both are postulated to play a role in modifying metabolic parameters. This randomized, double-blind study examined whether high doses of vitamin D for one year affected these biomarkers in subjects with both pre-diabetes and hypovitaminosis D.

Objective: To evaluate the effects of high dose of vitamin D supplementation for one year on cytokine, inflammatory and thrombotic parameters as well as IGF-1 levels in people with pre-diabetes and low levels of vitamin D.

Experimental Procedures: In Latino and African American subjects ≥40 years old, pre-diabetes was diagnosed by a 2 hr glucose level of 140-199 mg/dL and/or FPG 110-125 mg/dL.109 subjects had serum 25-OH vitamin D levels < 30 ng/mL and prediabetes and were randomized to either receive vitamin D (mean 88,865 IU/ week) (n=56) or placebo oil (n=53) for one year. Serum samples were collected at baseline, 6, 9 and 12 months for measurements of inflammatory cytokines IL6, TNFα, C-reactive protein (CRP) and PAI-1 and IGF-1 from 40 randomly selected subjects in each group.

Results: Serum 25-OH vitamin D levels of 20 ng/mL quickly rose to nearly 70 ng/mL in those receiving vitamin D and did not change in the placebo group. Two-way repeated measure ANOVA showed that there were no differences between the 2 groups in any of  the five selected parameters: TNFα (P=0.43); CRP (P=0.31); IL6 (P=0.67); PAI-1 (P=0.14); and IGF-1 (P=0.88).

Conclusion: High dose vitamin D supplementation in subjects with pre-diabetes and hypovitaminosis D for one year failed to affect levels of inflammatory cytokines, markers of inflammation, as well as PAI 1, and IGF-1.

Nothing to Disclose: IS, PD, RS, ML, TCF, MBD

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Grant Support: CDU-AXIS, U54MD007598, NIMHD