Department of Physiology, Faculty of Biology, University of Murcia, Murcia, Spain.
Chronobiol Int. 2011 May;28(5):425-33. doi: 10.3109/07420528.2011.574766.
The circadian rhythm of core body temperature is associated with widespread physiological effects. However, studies with other more practical temperature measures, such as wrist (WT) and proximal temperatures, are still scarce. The aim of this study was to investigate whether obesity is associated with differences in mean WT values or in its daily rhythmicity patterns. Daily patterns of cortisol, melatonin, and different metabolic syndrome (MetS) features were also analyzed in an attempt to clarify the potential association between chronodisruption and MetS. The study was conducted on 20 normal-weight women (age: 38 ± 11 yrs and BMI: 22 ± 2.6 kg/m(2)) and 50 obese women (age: 42 ± 10 yrs and BMI: 33.5 ± 3.2 kg/m(2)) (mean ± SEM). Skin temperature was measured over a 3-day period every 10 min with the "Thermochron iButton." Rhythmic parameters were obtained using an integrated package for time-series analysis, "Circadianware." Obese women displayed significantly lower mean WT (34.1°C ± 0.3°C) with a more flattened 24-h pattern, a lower-quality rhythm, and a higher intraday variability (IV). Particularly interesting were the marked differences between obese and normal-weight women in the secondary WT peak in the postprandial period (second-harmonic power [P2]), considered as a marker of chronodisruption and of metabolic alterations. WT rhythmicity characteristics were related to MetS features, obesity-related proteins, and circadian markers, such as melatonin. In summary, obese women displayed a lower-quality WT daily rhythm with a more flattened pattern (particularly in the postprandial period) and increased IV, which suggests a greater fragmentation of the rest/activity rhythm compared to normal-weight women. These 24-h changes were associated with higher MetS risk.
核心体温的昼夜节律与广泛的生理效应有关。然而，使用其他更实用的体温测量方法（如腕部（WT）和近端温度）的研究仍然很少。本研究旨在探讨肥胖是否与 WT 均值差异或其昼夜节律模式有关。还分析了皮质醇、褪黑素和不同代谢综合征（MetS）特征的日间模式，试图阐明chronodisruption 和 MetS 之间的潜在关联。该研究在 20 名正常体重女性（年龄：38 ± 11 岁，BMI：22 ± 2.6 kg/m²）和 50 名肥胖女性（年龄：42 ± 10 岁，BMI：33.5 ± 3.2 kg/m²）（均值 ± SEM）中进行。使用“Thermochron iButton”每 10 分钟测量皮肤温度，连续测量 3 天。使用时间序列分析的集成软件包“Circadianware”获得节律参数。肥胖女性的平均 WT（34.1°C ± 0.3°C）明显较低，24 小时模式更平坦，节律质量较低，日内变异性（IV）较高。特别有趣的是，肥胖女性和正常体重女性在餐后 WT 二次峰值（二次谐波功率 [P2]）之间存在显著差异，餐后 WT 二次峰值被认为是 chronodisruption 和代谢改变的标志。WT 节律特征与 MetS 特征、肥胖相关蛋白和昼夜节律标志物（如褪黑素）有关。总之，肥胖女性的 WT 日节律质量较低，模式更平坦（特别是在餐后），IV 增加，表明与正常体重女性相比，休息/活动节律的碎片化程度更高。这些 24 小时变化与更高的 MetS 风险相关。
