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Serum 25-hydroxyvitamin D and Ethnic Differences in Arterial Stiffness and Endothelial Function.

Alvarez JA, Gower BA, Calhoun DA, Judd SE, Dong Y, Dudenbostel T, Scholl J, Ashraf AP - J Clin Med Res (2012)

Bottom Line: It is not clear if ethnic differences in 25(OH)D mediate differences in vascular function.Results indicated that 25(OH)D was inversely associated with AIx75, supine systolic blood pressure (SBP), central aortic SBP and central aortic diastolic blood pressure (DBP), independent of age, sex, and percent body fat (standardized β= -0.29 to -0.43, P < 0.05 for all).AAs had greater AIx75 (P = 0.04) and PWV (P = 0.07) and lower FMD (P = 0.02) compared to EA after adjusting for age and percent body fat; further adjustment for 25(OH)D reduced the ethnic differences (P = 0.44, 0.53, and 0.20, respectively).

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition Sciences, University of Alabama Birmingham, Birmingham, AL, USA.

ABSTRACT

Background: Vitamin D reportedly influences vascular function, which is worse in African Americans (AAs) relative to European Americans (EAs). It is not clear if ethnic differences in 25(OH)D mediate differences in vascular function. This study examined the relationships of serum 25-hydroxyvitamin D (25(OH)D) with indicators of vascular function among healthy, young AA and EA adults.

Methods: This is a cross sectional study involving 23 AAs and 22 EAs. The main outcomes were augmentation index (AIx75), central aortic pressure, pulse wave velocity (PWV), flow-mediated dilation (FMD), and seated and supine blood pressures.

Results: Results indicated that 25(OH)D was inversely associated with AIx75, supine systolic blood pressure (SBP), central aortic SBP and central aortic diastolic blood pressure (DBP), independent of age, sex, and percent body fat (standardized β= -0.29 to -0.43, P < 0.05 for all). AAs had greater AIx75 (P = 0.04) and PWV (P = 0.07) and lower FMD (P = 0.02) compared to EA after adjusting for age and percent body fat; further adjustment for 25(OH)D reduced the ethnic differences (P = 0.44, 0.53, and 0.20, respectively).

Conclusion: The 25(OH)D was associated with vascular function in healthy adults, and lower 25(OH)D among AAs may contribute to their greater arterial stiffness and reduced endothelial function (Clinical trials.gov NCT01041365, NCT01041547).

No MeSH data available.


Related in: MedlinePlus

Relationship of 25(OH)D with AIx75, supine SBP, and aortic blood pressures, adjusted for age, sex, and percent body fat. Filled circles indicate AA, open circles indicate EA.
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Figure 1: Relationship of 25(OH)D with AIx75, supine SBP, and aortic blood pressures, adjusted for age, sex, and percent body fat. Filled circles indicate AA, open circles indicate EA.

Mentions: Simple Pearson correlation analyses indicated a significant relationship or a trend towards significance of 25(OH)D with several vascular outcomes, but not seated BP or supine DBP (Table 3). In exploratory MLR analyses for AIx75, supine SBP, and aortic BP as the dependent variables with age, sex, ethnic group, and 25(OH)D as the independent variables, ethnic group was not a significant predictor in the models (P = 0.43 to 0.87) whereas 25(OH)D was either statistically significant or approached significance (P = 0.04 to 0.098). Removal of ethnic group from the models resulted in a significant contribution of 25(OH)D (P < 0.05 for all). As depicted in Figure 1, the relationship of 25(OH)D with AIx75, supine SBP, aortic SBP, and aortic DBP remained statistically significant after incorporating percent body fat to the models. The addition of SES or physical activity to the models did not alter the results (P = 0.009 - 0.04) with the exception of attenuation of supine SBP (P = 0.08) after further adjustment for physical activity. Use of waist circumference or BMI in place of percent body fat as a measure of adiposity yielded similar results, and results were also similar if AIx was used in place of AIx75 (data not shown). The relationship of 25(OH)D with AIx75 was independent of supine and central aortic SBP (data not shown). In MLR models for PWV and FMD, 25(OH)D did not meet the a priori criteria for model entry with ethnic group in the models (P = 0.35 and 0.70, respectively), suggesting the relationship between 25(OH)D and these variables was not independent of ethnic group in analyses among the whole group.


Serum 25-hydroxyvitamin D and Ethnic Differences in Arterial Stiffness and Endothelial Function.

Alvarez JA, Gower BA, Calhoun DA, Judd SE, Dong Y, Dudenbostel T, Scholl J, Ashraf AP - J Clin Med Res (2012)

Relationship of 25(OH)D with AIx75, supine SBP, and aortic blood pressures, adjusted for age, sex, and percent body fat. Filled circles indicate AA, open circles indicate EA.
© Copyright Policy - open access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376878&req=5

Figure 1: Relationship of 25(OH)D with AIx75, supine SBP, and aortic blood pressures, adjusted for age, sex, and percent body fat. Filled circles indicate AA, open circles indicate EA.
Mentions: Simple Pearson correlation analyses indicated a significant relationship or a trend towards significance of 25(OH)D with several vascular outcomes, but not seated BP or supine DBP (Table 3). In exploratory MLR analyses for AIx75, supine SBP, and aortic BP as the dependent variables with age, sex, ethnic group, and 25(OH)D as the independent variables, ethnic group was not a significant predictor in the models (P = 0.43 to 0.87) whereas 25(OH)D was either statistically significant or approached significance (P = 0.04 to 0.098). Removal of ethnic group from the models resulted in a significant contribution of 25(OH)D (P < 0.05 for all). As depicted in Figure 1, the relationship of 25(OH)D with AIx75, supine SBP, aortic SBP, and aortic DBP remained statistically significant after incorporating percent body fat to the models. The addition of SES or physical activity to the models did not alter the results (P = 0.009 - 0.04) with the exception of attenuation of supine SBP (P = 0.08) after further adjustment for physical activity. Use of waist circumference or BMI in place of percent body fat as a measure of adiposity yielded similar results, and results were also similar if AIx was used in place of AIx75 (data not shown). The relationship of 25(OH)D with AIx75 was independent of supine and central aortic SBP (data not shown). In MLR models for PWV and FMD, 25(OH)D did not meet the a priori criteria for model entry with ethnic group in the models (P = 0.35 and 0.70, respectively), suggesting the relationship between 25(OH)D and these variables was not independent of ethnic group in analyses among the whole group.

Bottom Line: It is not clear if ethnic differences in 25(OH)D mediate differences in vascular function.Results indicated that 25(OH)D was inversely associated with AIx75, supine systolic blood pressure (SBP), central aortic SBP and central aortic diastolic blood pressure (DBP), independent of age, sex, and percent body fat (standardized β= -0.29 to -0.43, P < 0.05 for all).AAs had greater AIx75 (P = 0.04) and PWV (P = 0.07) and lower FMD (P = 0.02) compared to EA after adjusting for age and percent body fat; further adjustment for 25(OH)D reduced the ethnic differences (P = 0.44, 0.53, and 0.20, respectively).

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition Sciences, University of Alabama Birmingham, Birmingham, AL, USA.

ABSTRACT

Background: Vitamin D reportedly influences vascular function, which is worse in African Americans (AAs) relative to European Americans (EAs). It is not clear if ethnic differences in 25(OH)D mediate differences in vascular function. This study examined the relationships of serum 25-hydroxyvitamin D (25(OH)D) with indicators of vascular function among healthy, young AA and EA adults.

Methods: This is a cross sectional study involving 23 AAs and 22 EAs. The main outcomes were augmentation index (AIx75), central aortic pressure, pulse wave velocity (PWV), flow-mediated dilation (FMD), and seated and supine blood pressures.

Results: Results indicated that 25(OH)D was inversely associated with AIx75, supine systolic blood pressure (SBP), central aortic SBP and central aortic diastolic blood pressure (DBP), independent of age, sex, and percent body fat (standardized β= -0.29 to -0.43, P < 0.05 for all). AAs had greater AIx75 (P = 0.04) and PWV (P = 0.07) and lower FMD (P = 0.02) compared to EA after adjusting for age and percent body fat; further adjustment for 25(OH)D reduced the ethnic differences (P = 0.44, 0.53, and 0.20, respectively).

Conclusion: The 25(OH)D was associated with vascular function in healthy adults, and lower 25(OH)D among AAs may contribute to their greater arterial stiffness and reduced endothelial function (Clinical trials.gov NCT01041365, NCT01041547).

No MeSH data available.


Related in: MedlinePlus