Low-magnitude mechanical signals may be associated with increased bone cross-sectional area in adolescents and young adults with anorexia nervosa, according to a recent randomized clinical trial.

This double-blind study, published in JAMA Network Open, included 40 completers who received either a daily 10-minute Low-magnitude mechanical signals (LMMS) intervention (0.3g at 32-37 Hz) or sham (placebo) for six months. Researchers aimed to assess whether LMMS could help maintain or improve tibial trabecular volumetric bone mineral density (vBMD), the study’s primary outcome.

After six months, no statistically significant difference in tibial trabecular vBMD was observed between the LMMS and placebo groups. The LMMS group’s vBMD slightly decreased, from a median of 313.4 mg/cm³ to 309.4 mg/cm³, while the placebo group saw a slight increase, from 308.5 mg/cm³ to 319.2 mg/cm³ (95% CI for difference in median change, −57.11 to 2.49). However, the LMMS group showed significant increases in tibial total cross-sectional area (CSA) at the 4% site—from 795.8 mm² to 827.5 mm²—while the placebo group saw a decrease from 847.3 mm² to 843.3 mm² (95% CI, 2.94-162.53; P = .01). Similarly, trabecular CSA at the tibial 4% site increased in the LMMS group but declined in the placebo group (95% CI, 2.80-139.68; P = .02).

While LMMS did not improve trabecular vBMD, it was associated with significant changes in bone structure, achieved without weight-bearing exercise, often restricted in AN management. These findings indicate LMMS may offer a non-exercise approach for bone structure changes in adolescents and young adults with AN. Future research should explore longer durations and more severely malnourished populations to assess potential benefits.

Full disclosures are available in the published study.