Simm PJ, et al. - Bone, muscle, and balance outcomes were investigated in young patients taking antiepileptic drugs (AEDs). Compared to their matched controls, young people taking AEDs reported more fractures and had reductions in tibial volumetric bone mineral density (vBMD) and lower limb muscle force. These findings implied that further exploration of bone health issues of young patients on AED therapy was needed. To confirm these changes in the muscle–bone unit and to further explore the clinical outcomes, longitudinal studies were required.

• A case–control study utilizing an AED exposure–discordant matched-pair approach was performed.
• The authors included subjects (5-18 years) with at least 12 months of AED exposure.
• Pairs were twins, nontwin siblings and first cousins, sex- and age-matched (to within 2 years), allowing for greater power than with unrelated control subjects.
• They tested dual energy x-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and muscle force/balance, with questionnaires were administered for bone health and epilepsy details.

• The authors recruited 23 pairs, (median age 12.9 years [subjects] and 13.5 years [controls])-7 twin, 14 sibling, and 2 cousin pairs.
• Compared to controls, those taking AEDs had an increased prevalence of fractures (15 fractures in 8 subjects, compared with 4 fractures in 3 controls, p < 0.01).
• At the 4% site (tibia), trabecular volumetric bone mineral density (vBMD) measured by pQCT was reduced by 14% (p = 0.03) in subjects.
• At the tibia, subjects exerted a decreased maximum force compared to body weight (F_max total/g).
• No differences were observed in either bone mineral parameters measured by DXA or balance measures.