Exercise training upregulates intracellular nicotinamide phosphoribosyltransferase expression in humans: a systematic review with meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of human intervention studies
PubMed 37954044 · doi:10.3389/fpubh.2023.1287421
What was done
A systematic review and meta-analysis of literature from inception to July 5, 2023 (PubMed, Scopus, ClinicalTrials.gov, ICTRP) evaluating the effect of exercise training interventions on intracellular nicotinamide phosphoribosyltransferase (iNAMPT) expression in humans. Standardized mean differences were synthesized using a common-effect model.
What was found
Across 5 eligible studies, exercise training significantly upregulated iNAMPT with an overall Cohen's d of 0.81 (95% CI: 0.55 to 1.07), corresponding to an average 1.46-fold increase and an estimated 71.7% probability of upregulation in an individual adult. Probability of upregulation was estimated at 79.3% in men, 75.6% in young adults, 68.7% in older adults, 75.1% after aerobic exercise, and 66.4% after resistance exercise.
Why it matters
iNAMPT is the rate-limiting enzyme in mammalian NAD+ biosynthesis, which declines with age. This synthesis provides quantitative evidence that both aerobic and resistance exercise promote muscular iNAMPT expression in humans.
Limits
The analysis is restricted to only 5 studies; participant characteristics, baseline health status, and total sample size are not reported in the abstract. The use of a common-effect model may overlook potential between-study heterogeneity across diverse exercise modalities and training durations.
Cited by
- supports Fasting and physical exercise increase intracellular NAD levels in humans.