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Precise protein supplementation strategies for muscle improvement are still lacking. The timing or type of protein supplementation has been debated as a window of opportunity to improve muscle mass, strength, and physical performance. We conducted a network meta-analysis of randomized controlled trials with protein supplements and resistance training. PubMed, Web of Science, Cochrane Library, and SPORTDiscus databases were searched until May 1, 2023. We included 116 eligible trials with 4,711 participants that reported on 11 timing and 14 types of protein supplementation. Compared with placebo, protein supplementation after exercise (mean difference [MD]: 0.54 kg [95% confidence intervals 0.10, 0.99] for fat-free mass, MD: 0.34 kg [95% confidence intervals 0.10, 0.58] for skeletal muscle mass) and at night (MD: 2.85 kg [0.49, 5.22] for handgrip strength, MD: 12.12 kg [3.26, 20.99] for leg press strength) was most effective in improving muscle mass and strength, respectively (moderate certainty). Milk proteins (milk, whey protein, yogurt, casein, and bovine colostrum), red meat, and mixed protein were effective for gains in both muscle mass and strength (moderate certainty). No timing or type of protein showed a significant enhancement in physical performance (timed up-to-go test, 6-min walk test, and gait speed). Pre/postexercise and Night are key recommended times of protein intake to increase muscle mass and strength, respectively. Milk proteins are the preferred types of protein supplements for improving muscle mass and strength. Future randomized controlled trials that directly compare the effects of protein timing or types are needed. This trial was registered at International Prospective Register of Systematic Reviews as CRD42022358766. [ABSTRACT FROM AUTHOR]

Background: Advanced glycation end products (AGEs), a group of food processing byproducts, have been implicated in the development of various diseases. However, the relationship between circulating AGEs and sleep disorders remains uncertain. Methods: This cross-sectional study elucidated the association of plasma AGEs with sleep disorders among 1732 Chinese adults who participated in the initial visit (2019–2020) of the Tongji–Shenzhen Cohort (TJSZC). Sleep behavior was assessed using self-reported questionnaires and precise accelerometers. Plasma levels of AGEs, including Nε-(Carboxymethyl)lysine (CML), Nε-(Carboxyethyl)lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolone-2-yl)-ornithine (MG-H1), were quantified by ultra-high performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). Results: In logistic regression, per IQR increment in individual AGEs was associated with an increased odds ratio of short sleep duration (CML: 1.11 [1.00, 1.23]; CEL: 1.16, [1.04, 1.30]), poor sleep quality (CML: 1.33 [1.10, 1.60]; CEL: 1.53, [1.17, 2.00]; MG-H1: 1.61 [1.25, 2.07]), excessive daytime sleepiness (CML: 1.33 [1.11, 1.60]; MG-H1: 1.39 [1.09, 1.77]), and insomnia (CML: 1.29 [1.05, 1.59]). Furthermore, in weighted quantile sum regression and Bayesian kernel machine regression analyses, elevated overall exposure levels of plasma AGEs were associated with an increased risk of sleep disorders, including short sleep duration, poor sleep quality, excessive daytime sleepiness, and insomnia, with CML being identified as the leading contributor. Insufficient vegetable intake and higher dietary fat intake was associated with an increase in plasma CEL. Conclusions: These findings support a significant association between plasma AGEs and sleep disorders, indicating that AGEs may adversely influence sleep health and reducing the intake of AGEs may facilitate preventing and ameliorating sleep disorders. [ABSTRACT FROM AUTHOR]

Aims: Population‐based evidence regarding circulating advanced glycation end‐products (AGEs) and the risk of type 2 diabetes (T2D) is conflicting and insufficient. We aimed to examine the association of plasma AGEs and plasma soluble receptors for AGEs (sRAGE) with T2D. Materials and Methods: We conducted a hospital‐based case–control study including 1072 pairs (53.9 ± 9.7 years, 56.0% male) of newly diagnosed T2D and age‐ and sex‐matched controls. We further performed a nested case–control study within an ongoing prospective cohort consisting of 127 incident T2D cases and 381 well‐matched controls (62.2 ± 5.1 years, 71.7% male). Plasma AGEs were detected using liquid chromatography–tandem mass spectrometry, and plasma sRAGE was measured by enzyme‐linked immunosorbent assay. Conditional logistic regression was used to evaluate the association of plasma AGEs and sRAGE concentrations with T2D. Results: Higher plasma AGEs and lower sRAGE concentrations were associated with higher odds of T2D. The multivariable‐adjusted odds ratios of T2D comparing the highest with the lowest quartile levels were 3.28 (95% CI: 2.14, 5.02) for plasma AGEs and 0.25 (95% CI: 0.16, 0.39) for plasma sRAGE. Participants in the highest quartile of plasma AGEs and the lowest quartile of sRAGE concentrations had the greatest odds of T2D. The positive association of AGEs and inverse association of sRAGE with T2D risk was confirmed in the replication‐nested case–control study. Conclusions: Increased circulating AGEs and decreased sRAGE concentrations were associated with elevated T2D risk. Our findings may have implications for the strategies of T2D prevention and management. [ABSTRACT FROM AUTHOR]