肥胖白种人中低游离25-羟基维生素D、高维生素D结合蛋白和甲状旁腺激素。与骨骼存在复杂关联？
Low free 25-hydroxyvitamin D and high vitamin D binding protein and parathyroid hormone in obese Caucasians. A complex association with bone?
作者信息
Saarnio Elisa, Pekkinen Minna, Itkonen Suvi T, Kemi Virpi, Karp Heini, Ivaska Kaisa K, Risteli Juha, Koivula Marja-Kaisa, Kärkkäinen Merja, Mäkitie Outi, Sievänen Harri, Lamberg-Allardt Christel
机构信息
Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland.
Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.
出版信息
PLoS One. 2018 Feb 28;13(2):e0192596. doi: 10.1371/journal.pone.0192596. eCollection 2018.
BACKGROUND
Studies have shown altered vitamin D metabolism in obesity. We assessed differences between obese and normal-weight subjects in total, free, and bioavailable 25-hydroxyvitamin D (25(OH)D, 25(OH)DFree, and 25(OH)DBio, respectively), vitamin D binding protein (DBP), parathyroid hormone (PTH) and bone traits.
METHODS
595 37-47-year-old healthy Finnish men and women stratified by BMI were examined in this cross-sectional study. Background characteristic and intakes of vitamin D and calcium were collected. The concentrations of 25(OH)D, PTH, DBP, albumin and bone turnover markers were determined from blood. 25(OH)DFree and 25(OH)DBio were calculated. pQCT was performed at radius and tibia.
RESULTS
Mean±SE (ANCOVA) 25(OH)DFree (10.8±0.6 vs 12.9±0.4 nmol/L; P = 0.008) and 25(OH)DBio (4.1±0.3 vs 5.1±0.1 nmol/L; P = 0.003) were lower in obese than in normal-weight women. In men, 25(OH)D (48.0±2.4 vs 56.4±2.0 nmol/L, P = 0.003), 25(OH)DFree (10.3±0.7 vs 12.5±0.6 pmol/L; P = 0.044) and 25(OH)DBio (4.2±0.3 vs 5.1±0.2 nmol/L; P = 0.032) were lower in obese. Similarly in all subjects, 25(OH)D, 25(OH)DFree and 25(OH)DBio were lower in obese (P<0.001). DBP (399±12 vs 356±7mg/L, P = 0.008) and PTH (62.2±3.0 vs 53.3±1.9 ng/L; P = 0.045) were higher in obese than in normal-weight women. In all subjects, PTH and DBP were higher in obese (P = 0.047and P = 0.004, respectively). In obese women, 25(OH)D was negatively associated with distal radius trabecular density (R2 = 0.089, P = 0.009) and tibial shaft cortical strength index (CSI) (R2 = 0.146, P = 0.004). 25(OH)DFree was negatively associated with distal radius CSI (R2 = 0.070, P = 0.049), radial shaft cortical density (CorD) (R2 = 0.050, P = 0.045), and tibial shaft CSI (R2 = 0.113, P = 0.012). 25(OH)DBio was negatively associated with distal radius CSI (R2 = 0.072, P = 0.045), radial shaft CorD (R2 = 0.059, P = 0.032), and tibial shaft CSI (R2 = 0.093, P = 0.024).
CONCLUSIONS
The associations between BMI and 25(OH)D, 25(OH)DFree, and 25(OH)DBio, DBP, and PTH suggest that obese subjects may differ from normal-weight subjects in vitamin D metabolism. BMI associated positively with trabecular bone traits and CSI in our study, and slightly negatively with cortical bone traits. Surprisingly, there was a negative association of free and bioavailable 25(OH)D and some of the bone traits in obese women.
背景
研究表明肥胖人群的维生素D代谢存在改变。我们评估了肥胖与正常体重受试者在总25 - 羟基维生素D（25(OH)D）、游离25 - 羟基维生素D（25(OH)DFree）、生物可利用25 - 羟基维生素D（25(OH)DBio）、维生素D结合蛋白（DBP）、甲状旁腺激素（PTH）及骨特征方面的差异。
方法
在这项横断面研究中，对595名年龄在37 - 47岁、按体重指数（BMI）分层的芬兰健康男性和女性进行了检查。收集了背景特征以及维生素D和钙的摄入量。测定了血液中25(OH)D、PTH、DBP、白蛋白及骨转换标志物的浓度。计算了25(OH)DFree和25(OH)DBio。在桡骨和胫骨处进行了外周定量计算机断层扫描（pQCT）。
结果
在女性中，肥胖者的平均±标准误（协方差分析）25(OH)DFree（10.8±0.6 vs 12.9±0.4 nmol/L；P = 0.008）和25(OH)DBio（4.1±0.3 vs 5.1±0.1 nmol/L；P = 0.003）低于正常体重女性。在男性中，肥胖者的25(OH)D（48.0±2.4 vs 56.4±2.0 nmol/L，P = 0.003）、25(OH)DFree（10.3±0.7 vs 12.5±0.6 pmol/L；P = 0.044）和25(OH)DBio（4.2±0.3 vs 5.1±0.2 nmol/L；P = 0.032）较低。同样，在所有受试者中，肥胖者的25(OH)D、25(OH)DFree和25(OH)DBio较低（P<0.001）。肥胖女性的DBP（399±12 vs 356±7mg/L，P = 0.008）和PTH（62.2±3.0 vs 53.3±1.9 ng/L；P = 0.045）高于正常体重女性。在所有受试者中，肥胖者的PTH和DBP较高（分别为P = 0.047和P = 0.004）。在肥胖女性中，25(OH)D与桡骨远端小梁骨密度（R2 = 0.089，P = 0.009）及胫骨干皮质强度指数（CSI）（R2 = 0.146，P = 0.004）呈负相关。25(OH)DFree与桡骨远端CSI（R2 = 0.070，P = 0.049）、桡骨干皮质密度（CorD）（R2 = 0.050，P = 0.045）及胫骨干CSI（R2 = 0.113，P = 0.012）呈负相关。25(OH)DBio与桡骨远端CSI（R2 = 0.072，P = 0.045）、桡骨干CorD（R2 = 0.059，P = 0.032）及胫骨干CSI（R2 = 0.093，P = 0.024）呈负相关。
结论
BMI与25(OH)D、25(OH)DFree、25(OH)DBio、DBP及PTH之间的关联表明，肥胖受试者在维生素D代谢方面可能与正常体重受试者不同。在我们的研究中，BMI与小梁骨特征和CSI呈正相关，与皮质骨特征呈轻微负相关。令人惊讶的是，肥胖女性中游离和生物可利用的25(OH)D与某些骨特征呈负相关。
Zotero 插件