Switzer Boyd R, Atwood Jan R, Stark Aliza H, Hatch John W, Travis Rebecca, Ullrich Fred, Lyden Elizabeth R, Wu Xiumei, Chiu Yulanda, Smith Jan L
Department of Nutrition, University of North Carolina-Chapel Hill, Chapel Hill, NC 27599-7461, USA.
J Am Coll Nutr. 2005 Jun;24(3):217-26. doi: 10.1080/07315724.2005.10719468.
This study investigated the relationships of plasma vitamins A, E, and carotenoids with age, BMI and former/non-smoking history after adjusting for wheat bran supplementation.
All 39 African American women in the church-based, volunteer sample, 40-70 years old, supplemented their daily diets for 5-6 wks. with 1/2 cup of a riboflavin-spiked wheat bran cereal.
Urinary riboflavin concentrations increased from 0.8 +/- 0.1 mg/day at baseline to 7.5 +/- 0.5 mg/day after supplementation, confirming the 99.2 +/- 10.5% self-reported adherence. Plasma nutrient concentrations did not change significantly with supplementation nor was never/former smoking history related to diet. Plasma retinol and serum cholesterol were significantly higher (p < 0.0002) in persons older than 55 years compared to younger adults. Plasma retinol (microg/dL) but not serum cholesterol was associated significantly with menopausal status and hormone replacement therapy (HRT; p = 0.05); progressive increases in retinol concentrations were found in the women after adjusting for pre/post supplementation: lowest in pre-menopause (47.7 +/- 4.8); intermediate concentrations in post-menopause on HRT (54.6 +/- 3.0); highest level in post-menopause without HRT (61.1 +/- 3.0). Similarly, a progressive increase was found in lipid-unadjusted alpha-tocopherol concentrations and menopausal status with or without HRT. Vitamin A and cholesterol intakes were not significantly different by age group. Plasma carotenoids were not significantly different by age or fiber supplementation, but alpha- and beta-carotene and beta-cryptoxanthin were significantly lower with BMI > or = 30. In contrast to carotenoids, both plasma levels of gamma-tocopherol and lipid-adjusted gamma-tocopherol were significantly higher with obesity compared to those with BMI < 30.
Plasma alpha- and beta-carotene and beta-cryptoxanthin were negatively associated with obesity, whereas gamma-tocopherol measures were consistently elevated with high BMI. The increase in age-associated plasma retinol in postmenopausal women was likely related to decreased estrogen concentrations in the African American women. Smoking history was not influential in this study.
本研究在调整麦麸补充量后，调查血浆维生素A、E和类胡萝卜素与年龄、体重指数（BMI）以及既往/非吸烟史之间的关系。
在以教堂为基础的志愿者样本中，选取了39名年龄在40 - 70岁之间的非裔美国女性，她们在5 - 6周的时间里，每天食用半杯添加核黄素的麦麸谷物来补充日常饮食。
补充后尿核黄素浓度从基线时的0.8±0.1毫克/天增加到7.5±0.5毫克/天，证实了自我报告的99.2±10.5%的依从性。补充后血浆营养素浓度没有显著变化，既往/非吸烟史与饮食也无关。与年轻成年人相比，55岁以上人群的血浆视黄醇和血清胆固醇显著更高（p < 0.0002）。血浆视黄醇（微克/分升）而非血清胆固醇与绝经状态和激素替代疗法（HRT；p = 0.05）显著相关；在调整补充前后后发现，女性视黄醇浓度逐渐升高：绝经前最低（47.7±4.8）；接受HRT的绝经后中等浓度（54.6±3.0）；未接受HRT的绝经后最高水平（61.1±3.0）。同样，在未调整脂质的α - 生育酚浓度以及绝经状态（无论是否接受HRT）方面也发现了逐渐增加的情况。不同年龄组的维生素A和胆固醇摄入量没有显著差异。血浆类胡萝卜素在年龄或纤维补充方面没有显著差异，但当BMI≥30时，α - 和β - 胡萝卜素以及β - 隐黄质显著降低。与类胡萝卜素相反，肥胖者的血浆γ - 生育酚水平和经脂质调整的γ - 生育酚水平均显著高于BMI < 30者。
血浆α - 和β - 胡萝卜素以及β - 隐黄质与肥胖呈负相关，而γ - 生育酚水平在高BMI时持续升高。绝经后女性中与年龄相关的血浆视黄醇增加可能与非裔美国女性雌激素浓度降低有关。吸烟史在本研究中没有影响。
