Various biological processes show seasonal variations in humans, including important metabolic pathways. Seasonal changes in gene expression may affect annual differences in human immunity. We hypothesized that seasonal changes occur in clock gene expression levels that are associated with body mass index. Six non-obese men and five obese men participated in summer and winter. Two milliliters of saliva were collected, and total RNA was isolated from buccal epithelial cells in saliva. The clock gene expression levels of CLOCK, BMAL1, PER1, CRY2, REV-ERB-α, and REV-ERB-ß were examined by real-time PCR. Blood samples were measured HbA1c, glucose, insulin, adiponectin, IL-6, and TNF-α. Participants were asked about their sleeping hours and seasonal pattern. In the present study, CLOCK, BMAL1, and REV-ERB-β gene expression levels were significantly lower in winter than in summer; BMAL1 expression level was significantly lower in obese men than in non-obese. Concentrations of adiponectin and insulin were significantly different between obese and non-obese. No significant seasonal effects were observed in HbA1c, glucose, insulin, adiponectin, IL-6, or TNF-α concentrations. Sleep duration did not significantly differ between summer and winter. The short photoperiod during winter might contribute to seasonal alterations in the expression of clock genes in men. In the present results, revealed seasonal differences in clock gene expression levels might be associated with obesity. These results also showed the potential for measuring clock gene expression in a non-invasive manner using saliva samples.

各种生物过程显示出人类的季节性变化，包括重要的代谢途径。基因表达的季节性变化可能会影响人体免疫力的年度差异。我们假设季节性变化发生在与体重指数相关的时钟基因表达水平上。夏季和冬季，有6名非肥胖男性和5名肥胖男性参加。收集两毫升唾液，并从唾液的颊上皮细胞中分离总RNA。通过实时PCR检测CLOCK，BMAL1，PER1，CRY2，REV-ERB-α和REV-ERB-ß的时钟基因表达水平。测量血样中的HbA1c，葡萄糖，胰岛素，脂联素，IL-6和TNF-α。参与者被问到他们的睡眠时间和季节性模式。在本研究中，CLOCK，BMAL1，冬季REV-ERB-β基因表达水平明显低于夏季。肥胖男性的BMAL1表达水平显着低于非肥胖男性。肥胖和非肥胖者之间脂联素和胰岛素的浓度显着不同。在HbA1c，葡萄糖，胰岛素，脂联素，IL-6或TNF-α浓度中未观察到明显的季节性影响。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。肥胖男性的BMAL1表达水平显着低于非肥胖男性。肥胖和非肥胖者之间脂联素和胰岛素的浓度显着不同。在HbA1c，葡萄糖，胰岛素，脂联素，IL-6或TNF-α浓度中未观察到明显的季节性影响。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。肥胖男性的BMAL1表达水平显着低于非肥胖男性。肥胖和非肥胖者之间脂联素和胰岛素的浓度显着不同。在HbA1c，葡萄糖，胰岛素，脂联素，IL-6或TNF-α浓度中未观察到明显的季节性影响。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。肥胖和非肥胖者之间脂联素和胰岛素的浓度显着不同。在HbA1c，葡萄糖，胰岛素，脂联素，IL-6或TNF-α浓度中未观察到明显的季节性影响。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。肥胖和非肥胖者之间脂联素和胰岛素的浓度显着不同。在HbA1c，葡萄糖，胰岛素，脂联素，IL-6或TNF-α浓度中未观察到明显的季节性影响。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。夏季和冬季之间的睡眠时间没有显着差异。冬季短暂的光周期可能会导致男性时钟基因表达的季节性变化。在目前的结果中，时钟基因表达水平的季节性差异可能与肥胖有关。这些结果还显示了使用唾液样品以非侵入性方式测量时钟基因表达的潜力。