Creatine energy substrate increases bone density in the Pah enu2 classical PKU mouse in the context of phenylalanine restriction.
Level 5 - mechanism / opinion, no new human data
Animal and in vitro laboratory research
PubMed 37588420 · doi:10.1016/j.ymgmr.2023.100996
What was done
The authors investigated the effect of creatine on skeletal stem cell (SSC) differentiation and bone density in classical phenylketonuria (PKU). In vitro, Pah enu2 mouse SSCs undergoing osteoblast differentiation were treated with creatine to measure in situ alkaline phosphatase activity and intracellular ATP content. In vivo, wild-type littermates and Pah enu2 mice were assigned to control groups (untreated Pah enu2, dietary phenylalanine-restricted Pah enu2, and wild-type) or experimental groups receiving 1% creatine in drinking water for 60 days with or without dietary phenylalanine restriction. Bone metrics were assessed using microcomputed tomography.
What was found
In vitro, creatine increased intracellular ATP content and in situ alkaline phosphatase activity in Pah enu2 SSCs. In vivo, untreated and phenylalanine-restricted Pah enu2 control cohorts exhibited equivalent osteopenia. In phenylalanine-unrestricted Pah enu2 mice, creatine supplementation had no effect on bone density. In contrast, phenylalanine-restricted Pah enu2 mice receiving creatine showed increased bone density. No specific numerical values, effect sizes, or p-values were reported in the abstract.
Why it matters
Osteopenia in PKU often persists despite dietary phenylalanine control. This study provides preclinical proof-of-concept in mice that combining phenylalanine restriction with metabolic energy substrates like creatine may help address bone density deficits refractory to dietary monotherapy.
Limits
This is an animal and in vitro laboratory study, limiting direct clinical translation to humans. The abstract does not provide sample sizes (n), numerical bone density values, variance measures, or statistical test results.
Cited by
- partial Creatine stimulates osteoblasts and reduces osteoclast activity, favorably altering bone turnover similarly to bisphosphonates.