Department of Kinesiology, The University of Alabama in Huntsville, Huntsville, AL, United States.
Alabama College of Osteopathic Medicine, Dothan, AL, United States.
Complement Ther Med. 2020 Jun;51:102417. doi: 10.1016/j.ctim.2020.102417. Epub 2020 Apr 25.
It has been hypothesized that sweat loss during exercise causes a disruption in calcium homeostasis that activates bone resorption and over time leads to low bone mineral density. The purpose of this small pilot study was to determine whether dermal calcium loss from a bout of excessive sweating during light intensity physical activity triggers an increase in biomarkers of bone resorption. Biochemical markers related to bone homeostasis were measured before and after a 90 min Bikram hot yoga practice performed in a room heated to 105 °F with 40 % humidity. Participants were five females with a mean age of 47.4 ± 4.7 years. Nude body weight, serum total calcium (Ca), free ionized calcium, albumin, parathyroid hormone (PTH) and CTX-I were measured before and after a Bikram hot yoga practice. Mean estimated sweat loss was 1.54 ± 0.65 L, which elicited a 1.9 ± 0.9 % decrease in participant's body weight. Mean Ca concentration in sweat was 2.9 ± 1.7 mg/dl and the estimated mean total calcium lost was 41.3 ± 16.4 mg. Serum ionized Ca increased from 4.76 ± 0.29 mg/dl to 5.35 ± 0.36 mg/dl after the Bikram hot yoga practice (p = 0.0118). Serum PTH decreased from pre- 33.9 ± 3.3 pg/ml to post- 29.9 ± 2.1 pg/ml yoga practice (p = 0.0015) when adjusted for hemoconcentration (PTH), implying a decrease in PTH secretion. We conclude that calcium loss in sweat during 90 min of Bikram hot yoga did not trigger an increase in PTH secretion and did not initiate bone resorption.
据推测，运动时的汗液流失会导致钙稳态紊乱，从而激活骨吸收，随着时间的推移导致骨矿物质密度降低。本小型先导研究的目的是确定轻度体力活动期间大量出汗导致的皮肤钙流失是否会引发骨吸收生物标志物的增加。在 105°F 且湿度为 40%的房间中进行 90 分钟比克拉姆热瑜伽练习前后，测量与骨稳态相关的生化标志物。参与者为 5 名女性，平均年龄为 47.4±4.7 岁。在比克拉姆热瑜伽练习前后测量裸体体重、血清总钙 (Ca)、游离离子钙、白蛋白、甲状旁腺激素 (PTH) 和 CTX-I。估计平均出汗量为 1.54±0.65 L，导致参与者体重减轻 1.9±0.9%。汗液中 Ca 浓度的平均值为 2.9±1.7 mg/dl，估计总钙流失量为 41.3±16.4 mg。比克拉姆热瑜伽练习后血清离子钙从 4.76±0.29 mg/dl 增加到 5.35±0.36 mg/dl（p=0.0118）。比克拉姆热瑜伽练习后，血清 PTH 从 33.9±3.3 pg/ml 降低至 29.9±2.1 pg/ml（p=0.0015），当根据血液浓缩（PTH）调整时，表明 PTH 分泌减少。我们得出结论，90 分钟比克拉姆热瑜伽期间汗液中的钙流失并未引发 PTH 分泌增加，也未引发骨吸收。
