Glukosestoffwechsel im fortgeschrittenen Lebensalter

Effect of Total and Partial Meal Replacements on Factors Related to Glucose Metabolism: A Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Although some evidence shows the beneficial effects of meal replacements (MRs) on glucose metabolism as one of the main factors of diabetes, there are still no comprehensive findings in this field.

OBJECTIVE

We investigated the effects of total and partial MRs on fasting blood sugar (FBS), insulin, glycated hemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR) in this comprehensive study and meta-analysis.

DATA SOURCES

To find pertinent randomized controlled trials (RCTs) up to March 2024, databases including PubMed/Medline, Web of Science, Scopus, and Embase were searched.

DATA EXTRACTION

This study included all RCTs investigating the effects of MRs on factors related to glucose metabolism. The pooled weighted mean difference (WMD) and 95% CIs were computed using the random-effects model.

DATA ANALYSIS

The findings from 52 studies indicated significant reductions in FBS (WMD: -3.10 mg/dL; 95% CI: -4.99, -1.20; P < .001), insulin (WMD: -1.79 μU/mL; 95% CI: -3.51, -0.08; P = .40), HOMA-IR (WMD: -0.86; 95% CI: -1.68, -0.04; P = .040), and HbA1c (WMD: -0.24%; 95% CI: -0.35%, -0.13%; P < .001) levels following MR consumption compared with the control group. The findings obtained from the subgroup analysis showed that MRs cause a greater decrease in FBS, insulin, and HOMA-IR in the >50-years age group compared with those aged ≤50 years and also during interventions ≤24 weeks compared with >24 weeks.

CONCLUSION

In conclusion, it appears that MRs, along with other lifestyle factors, can lead to significant improvements in glucose metabolism.

Skeletal muscle atrophy: From mechanisms to treatments

Skeletal muscle is a crucial tissue for movement, gestural assistance, metabolic homeostasis, and thermogenesis. It makes up approximately 40% of the total body weight and 50% of total protein. However, several pathological abnormalities (e.g., chronic diseases, cancer, long-term infection, aging) can induce an imbalance in skeletal muscle protein synthesis and degradation, which triggers muscle wasting and even leads to atrophy. Skeletal muscle atrophy is characterized by weakening, shrinking, and decreasing muscle mass and fiber cross-sectional area at the histological level. It manifests as a reduction in force production, easy fatigue and decreased exercise capability, along with a lower quality of life. Mechanistically, there are several pathophysiological processes involved in skeletal muscle atrophy, including oxidative stress and inflammation, which then activate signal transduction, such as the ubiquitin proteasome system, autophagy lysosome system, and mTOR. Considering the great economic and social burden that muscle atrophy can inflict, effective prevention and treatment strategies are essential but still limited. Exercise is widely acknowledged as the most effective therapy for skeletal muscle atrophy; unfortunately, it is not applicable for all patients. Several active substances for skeletal muscle atrophy have been discovered and evaluated in clinical trials, however, they have not been marketed to date. Knowledge is being gained on the underlying mechanisms, highlighting more promising treatment strategies in the future. In this paper, the mechanisms and treatment strategies for skeletal muscle atrophy are briefly reviewed.