Metabolic effects of alternate-day fasting in males with obesity with or without type 2 diabetes

Chrononutrition in the context of Ramadan: Potential implications

Every year, healthy adult Muslims practice dawn to sunset fasting for a whole lunar month. No food or fluid is allowed for the fasting time window. After sunset, eating is allowed. The dramatic change in the timing of meals is accompanied by changes in sleeping hours and thus alterations in circadian rhythms. Hormonal mechanisms mainly determined by the latter also change. These include shifts in cortisol and melatonin. Food-dependent hormones such as Ghrelin and leptin also show changes. A well-established principle of chrononutrition is that the timing of eating may be as or more important than the content of food. Ramadan fasting (RF) is distinct from other forms of intermittent fasting, although there are also some similarities with time restricted eating (TRE). Both have been shown to have health benefits. Here, we examine existing literature to understand and learn from this very commonly practiced form of fasting and its relationships to circadian rhythms and homoeostatic mechanisms.

Effects of Aerobic Training and Semaglutide Treatment on Pancreatic β-Cell Secretory Function in Patients With Type 2 Diabetes

CONTEXT

Prior to this study, it is known that type 2 diabetes is linked to obesity and a sedentary lifestyle, leading to inadequate β-cell function and insulin resistance. Limited research has explored the metabolic effects of combining exercise training with antidiabetic medications, particularly focusing on insulin secretion in patients with type 2 diabetes and moderately preserved β-cell function.

OBJECTIVE

The effect of the interaction of semaglutide and physical training on pancreatic β-cell secretory function is unknown in patients with type 2 diabetes.

METHODS

Thirty-one patients with type 2 diabetes underwent 12 weeks of aerobic training alone or concurrent to treatment with semaglutide. Patients randomly allocated to concurrent semaglutide and training were treated with semaglutide for 20 weeks before the training and evaluated at inclusion and again before and after the training intervention. Patients randomized to training were evaluated before and after training. The primary outcome was a change in insulin secretory capacity with training, evaluated by a 2-stepped hyperglycemic (20 and 30 mM) clamp.

RESULTS

Training increased the incremental area under the curve for insulin from 21 to 27 nM × 2 hours (ratio 1.28, 95% CI 1.02-1.60) during clamp step 1 and from 40 to 64 nM × 2 hours (ratio 1.61, 95% CI 1.25-2.07) during step 2. Semaglutide treatment increased insulin secretion from 16 to 111 nM × 2 hours (ratio 7.10, 95% CI 3.68-13.71), and from 35 to 447 nM × 2 hours (ratio 12.74, 95% CI 5.65-28.71), correspondingly. Semaglutide and training increased insulin secretion from 130 to 171 nM × 2 hours (ratio 1.31, 95% CI 1.06-1.63), and from 525 to 697 nM × 2 hours (ratio 1.33, 95% CI 1.02-1.72), correspondingly. The median increase in total insulin secretion with the combination was 134 nM × 2 hours greater (95% CI 108-232) than with training.

CONCLUSION

The combination of aerobic training and semaglutide treatment synergistically improved β-cell secretory function. (ClinicalTrials.gov number, ID NCT04383197).

Effects of Intermittent Fasting on Regulation of Metabolic Homeostasis: A Systematic Review and Meta-Analysis in Health and Metabolic-Related Disorders

Intermittent fasting (IF) is an emerging dietetic intervention that has been associated with improved metabolic parameters. Nowadays, the most common IF protocols are Alternate-Day Fasting (ADF) and Time-Restricted Fasting (TRF), but in this review and meta-analysis we have also considered Religious Fasting (RF), which is similar to TRF but against the circadian rhythm. The available studies usually include the analysis of a single specific IF protocol on different metabolic outcomes. Herein, we decided to go further and to conduct a systematic review and meta-analysis on the advantages of different IF protocols for metabolic homeostasis in individuals with different metabolic status, such as with obesity, diabetes mellitus type 2 (T2D) and metabolic syndrome (MetS). Systematic searches (PubMed, Scopus, Trip Database, Web of Knowledge and Embase, published before June 2022) of original articles in peer-review scientific journals focusing on IF and body composition outcomes were performed. Sixty-four reports met the eligibility criteria for the qualitative analysis and forty-seven for the quantitative analysis. Herein, we showed that ADF protocols promoted the major beneficial effects in the improvement of dysregulated metabolic conditions in comparison with TRF and RF protocols. Furthermore, obese and MetS individuals are the most benefited with the introduction of these interventions, through the improvement of adiposity, lipid homeostasis and blood pressure. For T2D individuals, IF impact was more limited, but associated with their major metabolic dysfunctions-insulin homeostasis. Importantly, through the integrated analysis of distinct metabolic-related diseases, we showed that IF seems to differently impact metabolic homeostasis depending on an individual's basal health status and type of metabolic disease.