The Effect of Carnosine Supplementation on Musculoskeletal Health in Adults with Prediabetes and Type 2 Diabetes: A Secondary Analysis of a Randomized Controlled Trial.

Background/objectives: Type 2 diabetes (T2D) is associated with an increased risk of adverse musculoskeletal outcomes likely due to heightened chronic inflammation, oxidative stress, and advanced glycation end-products (AGE). Carnosine has been shown to have anti-inflammatory, anti-oxidative, and anti-AGE properties. However, no clinical trials have examined the impact of carnosine on musculoskeletal health in adults with prediabetes or T2D.

Methods: In a randomized, double-blind clinical trial, 49 participants with prediabetes or T2D and without existing musculoskeletal conditions were assigned to receive either 2 g/day carnosine or matching placebo for 14 weeks. Whole-body dual-energy X-ray absorptiometry (DXA) was used to assess body composition, and peripheral quantitative computed tomography (pQCT) was used to assess bone health at the distal and proximal tibia.

Results: Forty-three participants completed this study. Carnosine supplementation had no effect on change in hand grip strength (HGS) or upper-limb relative strength (HGS/lean mass) versus placebo. Change in appendicular lean mass, percentage of body fat, visceral fat area, proximal tibial cortical volumetric bone mineral density (vBMD), distal tibial trabecular vBMD, and stress-strain index did not differ with carnosine compared to placebo. Fourteen weeks of carnosine supplementation did not improve muscle strength, body composition, or bone health in adults with prediabetes or T2D.

Conclusions: Carnosine supplementation may not be an effective approach for improving musculoskeletal health in adults with prediabetes and T2D without musculoskeletal conditions. However, appropriately powered trials with longer duration are warranted to confirm our findings. The trial was registered at clinicaltrials.gov (NCT02917928).