Discussion
obesity, obese, CKD, TNF-α, overweight, adiposity
OBESITY, OBESE, ADIPOSITY
The preliminary results of this 12-week study showed that compared with the CD group, the eGFR in the TRF group increased by 3.1 ml/min/1.73mWe also focused on patient adherence in our study, and from the results, patients in the TRF group experienced some hunger, but within tolerable range, and stated that TRF adherence was good. Likewise, in another similar 2×6 week crossover study involving 24 patients, it was observed that short-term TRF was safe, feasible and well tolerated in healthy middle-aged and elderly adults (In this study, we tried to explain the underlying mechanism of TRF’s benefit for CKD patients. We believe that it may be due to the following reasons.The first is the change in body composition. Our study reported a significant decrease in body weight and BMI in the TRF group. At the same time, the body composition analysis indicated not only a reduction in adiposity (body fat mass and visceral fat), but also a parallel reduction in muscle and water. It showed that patients in the TRF group were more likely to reduce protein intake and calorie intake when they followed TRF and a low-protein diet. This reduced the burden on the kidneys and improved renal outcomes. The renal risks of obesity include renal function impairment and damage to renal structure (Secondly, TRF may cause changes in the gut microbiota. Although our study did not affect the species diversity of gut microbiota, TRF induced positive changes in the gut microbiota. Significant elevation of harmful gut microbiota was observed in the TRF group before the intervention. Yet in the limited studies, it was not enough to summarize the role and influence of The third reason may be inflammatory factors. However, we observed no conclusive positive results in our study. We observed the effect of TRF on the inflammatory factors TNF-α, IL-6 and CRP, but they showed different tendencies separately. Although animal studies have shown that TRF can reduce the inflammatory factors TNF-α and IL-6 (In addition, in our study, we also observed a decrease in serum phosphate and uric acid, maintenance of total protein and albumin, in the TRF group. This may have been attributed to a significant decrease in patients’ dietary intake, with reduced phosphorus, protein and purine intake which may also lead to further approval of renal outcomes.To our knowledge, this is the first study to evaluate the effects of TRF in overweight and obese moderate-to-severe CKD in China, with low drop-out rates, and specifically assessing dietary intake and gut microbiota. Nonetheless, our exploratory study has several limitations. Firstly, due to the specificity of the intervention and the impact of COVID-19, this study is merely a small sample size study. Although only 28 patients were ultimately included in the study, the patients were representative. They were sourced from outpatient clinics and recruited and included in strict accordance with the study criteria without special selection. However, because of the relatively small sample size, the conclusions we drew were cautious. Due to the small sample and imperfect compliance, it may not reflect the true effect of TRF intervention. Additionally, this was a non-randomized controlled study, and there may be some variation in individuals’ self-discipline regarding their lifestyles and such as dietary control between the two groups. This may have introduced bias into the analysis of the two groups’ results, but may be helpful in terms of adherence. Finally, because of the short duration of the intervention in this study, and the lack of follow-up for patients in both groups, we could not determine the long-term efficacy of TRF therapy.