Alterations in Hemoglobin and Serum 25-hydroxyvitamin D are Related Before and After Weight Loss Independent of African Admixture

作者：Carter Stephen J^*; Plaisance Eric P; Fisher Gordon; Fernandez Jose R; Gower Barbara A; Hunter Gary R

来源：International Journal of Sport Nutrition and Exercise Metabolism, 2017, 27(1): 59-66.

DOI：10.1123/ijsnem.2016-0002

• adiposity
• dieting
• hormones
• race disparity

African American (AA) and European American (EA) women often exhibit differences in hemoglobin (Hb) and 25-hydroxyvitamin D [25(OH)D], both of which can be altered by calorie restriction leading to weight loss. Given these known differences, it is of clinical interest to examine the potential for race-specific, adverse responses to weight loss. Sixty-four overweight (BMI 27-29.9 kg/m(2)), premenopausal women consumed a standardized, very-low calorie diet to reduce BMI < 25 kg/m(2). Ancestry informative markers provided estimates of African admixture, an objective mean of expressing race. Blood sampling and anthropometric measures were performed at baseline and upon meeting target BMI. At baseline, in the overweight state, Hb (g/dL) (AA, 11.7 +/- 0.9 vs. EA, 12.5 +/- 0.8; p <.01) and 25(OH)D (nmol/L) (AA, 35.7 +/- 12.9 vs. EA, 57.0 +/- 20.0; p <.01) were lower in AAs. After weight loss, Hb decreased (AA,-0.5 +/- 0.7 vs. EA,-0.4 +/- 0.6; p =.48) to a similar extent among races. Conversely, 25(OH)D increased (AA, 43.4 +/- 14.0 vs. EA 68.2 +/- 24.3; p <.01) though the magnitude of change (Delta) was not different (AA, +7.8 +/- 13.5 vs. EA, +11.2 +/- 16.7; p =.37) between races. Multiple linear regression revealed a positive association between Delta Hb and Delta 25(OH)D (r =.386; p <.01) adjusted for African admixture, Delta testosterone, and Delta body fat%. Path analyses revealed a significant indirect effect of Delta body fat% on Delta Hb through Delta 25(OH)D, beta =-0.023, CI [-0.06,-0.004]. Following 15% weight loss, participants with the largest increase in serum 25(OH)D exhibited the smallest decrease in Hb. Future research should clarify the optimal degree of calorie restriction to stimulate weight loss while mitigating the potential risk of anemia associated with dieting efforts.

• 出版日期2017-2