Svartberg Johan, Jorde Rolf, Sundsfjord Johan, Bønaa Kaare H, Barrett-Connor Elizabeth
Department of Medicine, University Hospital of North Norway, N-9038 Tromsø.
J Clin Endocrinol Metab. 2003 Jul;88(7):3099-104. doi: 10.1210/jc.2002-021878.
Studies of seasonal variation in male testosterone levels show contradictory results. We report here a cross-sectional study of the seasonal variation in total and free testosterone, LH, and SHBG levels in 1548 men living in north Norway, a population exposed to a wide seasonal variation in temperature and daylight. Total testosterone showed a bimodal seasonal variation (P < 0.001) with a small peak in February, the nadir in June, and a more prominent peak in October and November. Free testosterone also showed a significant seasonal pattern (P < 0.001), with the peak in December and the nadir in August. These patterns persisted after adjusting for age and waist to hip ratio (P < 0.001). Lowest testosterone levels occurred in months with the highest temperatures and longest hours of daylight. Waist to hip ratio paralleled the change in daylight and temperature, with the highest values during the summer and was thus inversely related to the seasonal testosterone variation. The variations in hormone levels were large, with a 31% difference between the lowest and highest monthly mean level of free testosterone. Prospective studies are needed to establish the direction of the association and its etiology.
关于男性睾酮水平季节性变化的研究结果相互矛盾。我们在此报告一项横断面研究，该研究针对居住在挪威北部的1548名男性的总睾酮、游离睾酮、促黄体生成素（LH）和性激素结合球蛋白（SHBG）水平的季节性变化展开，该人群暴露于温度和日照时长存在广泛季节性变化的环境中。总睾酮呈现双峰式季节性变化（P < 0.001），2月出现一个小高峰，6月为最低点，10月和11月出现更显著的高峰。游离睾酮也呈现出显著的季节性模式（P < 0.001），12月达到高峰，8月为最低点。在对年龄和腰臀比进行校正后，这些模式依然存在（P < 0.001）。最低的睾酮水平出现在温度最高和日照时长最长的月份。腰臀比与日照和温度的变化平行，在夏季达到最高值，因此与睾酮的季节性变化呈负相关。激素水平的变化幅度很大，游离睾酮最低和最高月平均水平之间相差31%。需要进行前瞻性研究以确定这种关联的方向及其病因。
