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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #338632

Title: Race or vitamin D: A determinant of intima media thickness in obese adolescents?

item BACHA, FIDA - Children'S Nutrition Research Center (CNRC)
item ARSLANIAN, SILVA - University Of Pittsburgh Medical Center

Submitted to: Pediatric Diabetes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2016
Publication Date: 11/17/2016
Citation: Bacha, F., Arslanian, S.A. 2016. Race or vitamin D: A determinant of intima media thickness in obese adolescents? Pediatric Diabetes. doi:10.1111/pedi.12472.

Interpretive Summary: In previous studies, racial difference in the thickness of the inner lining of the blood vessels (called intima media thickness or IMT) was observed. We investigated whether this race difference can be accounted for by a difference in vitamin D levels, known to be lower in African American (AA) vs. American White (AW) youth. We measured IMT, vitamin D levels and other relevant variables in AA and AW adolescents. We found that AA youth have higher IMT and lower vitamin D levels compared with their AW peers. Vitamin D levels contributed to the IMT measure. However, the racial difference in IMT could not be completely attributed to a difference in vitamin D levels.Our findings support the recommendation that effort to prevent cardio vascular disease should start at a young age, especially in AA children.

Technical Abstract: Carotid intima media thickness (IMT), a predictor of cardiovascular events, is reported to be higher in African-American (AA) vs. White (AW) individuals. We investigated whether racial differences in IMT in obese adolescents could be explained by differences in 25 hydroxy-vitamin D [25(OH)D]. A total of 63 obese adolescents had 25(OH)D levels, determination of IMT, body composition, insulin sensitivity (IS) by hyperinsulinemic-euglycemic clamp, lipids and blood pressure (BP). IMT was higher and 25(OH)D lower in AA vs AW. IMT correlated with 25(OH)D level (r = -0.38, P = .002) but not with IS. In multiple regression analysis, race, HbA1c, BP and age, and not 25(OH)D, BMI or IS, were the significant determinants of IMT (R2 = 0.44, P < .001). Without race in the model, 25(OH)D (ß = -0.36, P = .009) contributed to the variance in IMT (R2 = 0.32, P = .007). Obese AA adolescents vs AW, have higher IMT, explained by race, BP, and HbA1c. Although 25(OH)D levels contribute to the variance in IMT, the observed racial difference in IMT could be mediated through other unknown race-related factors besides 25(OH)D.