Is sarcopenia associated with osteoporosis? A cross-sectional study of 262 women with hip fracture.

BACKGROUND: Several lines of evidence support the view that sarcopenia and osteoporosis are strictly connected. However, the capability of the updated sarcopenia definition to capture the concomitant presence of osteoporosis has been scarcely investigated. AIM: The main aim was to assess the association between sarcopenia defined according to the revised criteria from the European Working Group on Sarcopenia in Older People (EWGSOP2) and osteoporosis in women with a hip fracture. A second aim was to investigate the thresholds for low appendicular lean mass (aLM) and handgrip strength to optimize osteoporosis detection. DESIGN: Cross-sectional study. SETTING: Rehabilitation hospital. POPULATION: Women with subacute hip fracture. METHODS: A scan by dual-energy X-ray absorptiometry (DXA) was performed to assess body composition. A Jamar dynamometer was used to measure handgrip strength. Sarcopenia was diagnosed with both handgrip strength <16 kg and aLM <15 kg. Osteoporosis was identified with femoral bone mineral density lower than 2.5 standard deviations below the mean of the young reference population. RESULTS: We studied 262 of 290 women. Osteoporosis was found in 189 of the 262 women (72%; 95% CI: 67-78%) whereas sarcopenia in 147 (56%; 95% CI: 50-62%). After adjustment for age, time interval between fracture and DXA scan and body fat percentage the odds ratio to have osteoporosis for a sarcopenic woman was 2.30 (95% CI: 1.27-4.14; P=0.006). Receiver operating characteristic curve analyses showed that the best cut-off points to discriminate osteoporosis were 20 kg for handgrip strength and 12.5 kg for aLM. Adopting the optimized thresholds to define sarcopenia, the adjusted odds ratio to have osteoporosis for a sarcopenic woman was 3.68 (95% CI: 1.93-7.03; P<0.001). CONCLUSIONS: This preliminary study shows a positive association between sarcopenia defined according to the EWGSOP2 criteria and osteoporosis in 262 women with hip fracture. The association may be bettered by refining the cut-off points for low aLM and handgrip strength. CLINICAL REHABILITATION IMPACT: Sarcopenia seems to be a risk factor for osteoporosis in hip-fracture women. The issue, and the potential role of optimized thresholds should be addressed by robust longitudinal studies.