Bahijri Suhard M, Ajabnoor Ghada M, Borai Anwar, Al-Aama Jumana Y, Chrousos George P
Department of Clinical Biochemistry, Faculty of Medicine, Saudi Diabetes Research Group, King Fahd Medical Research Center, King Abdulaziz University, PO Box 4873, Jeddah 21412, Saudi Arabia.
Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
Ther Adv Endocrinol Metab. 2015 Oct;6(5):223-32. doi: 10.1177/2042018815594527.
Each year Muslims fast from dawn to sunset for 1 month (Ramadan). In Saudi Arabia, the sleep-wake cycle during Ramadan is severely disturbed and is associated with abolition of the circadian cortisol rhythm, exposing Saudis to continuously increased cortisol levels, which may influence the immune response. In addition to cortisol, sleep and fasting affect the secretion of parathyroid hormone (PTH) and hence bone metabolism.
Our objective was to investigate the effect of Ramadan type fasting on secretory patterns of PTH, markers of bone metabolism, and serum immunoglobulins. Blood samples from healthy young volunteers were collected at 9 a.m. and 9 p.m. (± 1 hour) before (Shaban) and 2 weeks into Ramadan. Calcium, phosphorus, magnesium, albumin, alkaline phosphatase, 25-OH vitamin D, intact PTH (iPTH), and immunoglobulin (Ig) A, M and G were measured.
During Ramadan, evening-adjusted calcium was higher (p = 0.036) and phosphate lower (p < 0.001) than the corresponding morning value. Moreover, the Ramadan mean morning phosphate was higher and the evening level lower was than Shabaan values (p = 0.010 and p <0.001, respectively), while mean iPTH level was decreased compared with the morning value (p = 0.001), and the evening mean during Shabaan (p = 0.029). Mean IgG concentration was significantly lower during Ramadan (p = 0.003 and p = 0.021 for morning and evening, respectively).
Changes in dietary practices during Ramadan modulated PTH secretion to a pattern which might be beneficial to bone health. Combined effects of fasting and disturbed sleep led to a noted decrease in IgG level. Therefore, a possible beneficial effect of fasting on bone turnover is combined with decreased immune response.
每年穆斯林会在斋月期间从黎明到日落禁食1个月。在沙特阿拉伯，斋月期间的睡眠-清醒周期受到严重干扰，且与昼夜皮质醇节律的消失有关，这使沙特人暴露于持续升高的皮质醇水平下，可能会影响免疫反应。除皮质醇外，睡眠和禁食还会影响甲状旁腺激素（PTH）的分泌，进而影响骨代谢。
我们的目的是研究斋月期间禁食对PTH分泌模式、骨代谢标志物和血清免疫球蛋白的影响。在斋月前（沙班月）上午9点和晚上9点（±1小时）以及斋月开始2周后，采集健康年轻志愿者的血样。检测钙、磷、镁、白蛋白、碱性磷酸酶、25-羟基维生素D、完整PTH（iPTH）以及免疫球蛋白（Ig）A、M和G。
在斋月期间，经晚上调整后的钙水平高于相应的早晨值（p = 0.036），而磷酸盐水平低于早晨值（p < 0.001）。此外，斋月期间早晨的平均磷酸盐水平高于沙班月，晚上的水平低于沙班月（分别为p = 0.010和p <0.001），而iPTH的平均水平与早晨值相比有所下降（p = 0.001），与沙班月期间晚上的平均值相比也下降了（p = 0.029）。斋月期间IgG的平均浓度显著降低（早晨和晚上分别为p = 0.003和p = 0.021）。
斋月期间饮食习惯的改变将PTH分泌调节至可能有益于骨骼健康的模式。禁食和睡眠紊乱的综合作用导致IgG水平显著下降。因此，禁食对骨转换可能产生的有益作用与免疫反应降低并存。
