Intermittent fasting can be effective in reducing metabolic disorders and age-related diseases. However, there remain questions about the effects of fasting with respect to the age in which fasting begins, the fasting models, and the mechanisms involved. We investigated the effects of age of beginning fasting and chronic mild and severe fasting models on blood pressure (BP), insulin/glucose profile, and expression of klotho, sirtuin1 (SIRT1), and sirtuin3 (SIRT3) in male Wistar rats. Young (3 months), middle-aged (12 months), and old (22 months) animals were randomly divided into three subgroups and fed as ad libitum (AL), AL with fasting 1 day per week (FW), and AL with fasting every other day (EOD), respectively, for 3 months. The FW reduced the weight gain in young animals (p < 0.001 vs. AL), whereas EOD induced weight loss in all three age categories (p < 0.001). Aging was associated with high BP, high glucose, and insulin levels. Both FW and EOD feedings decreased BP and blood glucose level (p < 0.001) and EOD decreased insulin level (p < 0.05 vs. AL) in old animals. Parallel to aging, the expression of SIRT1 and klotho significantly decreased in plasma and EOD feeding recovered this defect. Both FW and EOD feedings increased the expression of SIRT3 in middle-aged and old rats. Age is a determining factor for the effectiveness of fasting and old animals respond more desirably to fasting. The effect of EOD fasting is more effective than FW fasting in improving the metabolic factors, partly through the recovery of SIRT1 and klotho.

中文翻译：

---

年龄和禁食模型对雄性大鼠血压，胰岛素/葡萄糖谱和长寿蛋白表达的影响。

间歇性禁食可有效减少代谢紊乱和与年龄有关的疾病。然而，仍然存在关于禁食对禁食开始年龄的影响，禁食模型以及所涉及的机制的问题。我们调查了开始禁食的年龄以及慢性轻度和重度禁食模型的年龄对雄性Wistar大鼠血压（BP），胰岛素/葡萄糖谱以及klotho，sirtuin1（SIRT1）和sirtuin3（SIRT3）表达的影响。将幼小（3个月），中年（12个月）和大龄（22个月）的动物随机分为三个亚组，随意喂养（AL），每周禁食1天（FW）的AL和每星期禁食1天的AL每隔一天禁食3个月。FW减少了年幼动物的体重增加（p 相对于AL，<0.001），而EOD在所有三个年龄段均导致体重减轻（p  <0.001）。衰老与高血压，高血糖和胰岛素水平有关。FW和EOD喂养均降低BP和血糖水平（p  <0.001），而EOD降低胰岛素水平（p ＜0.05 vs. AL）。在衰老的同时，血浆中SIRT1和klotho的表达显着下降，而EOD喂养恢复了该缺陷。FW和EOD喂养均可增加SIRT3在中老年大鼠中的表达。年龄是禁食效果的决定因素，而老动物对禁食的反应更理想。EOD禁食的效果比FW禁食更有效地改善了代谢因子，部分原因是通过恢复SIRT1和klotho。