Osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia are frequently prevalent in patients with primary biliary cholangitis (PBC), according to data published in the European Journal of Gastroenterology and Hepatology. In a cohort of patients with PBC, osteoporosis, sarcopenia, and vertebral fracture were prevalent, and diagnosis with one tended to predict diagnosis of another.
This cross-sectional study enrolled patients diagnosed with PBC between 2017 and 2019 at participating medical centers in Japan. Eligible patients had been evaluated for skeletal muscle mass index, handgrip strength, and bone mineral density (BMD). The primary outcomes were diagnosis of vertebral fractures, osteoporosis, or sarcopenia. Vertebral fractures were identified using spinal lateral X-rays. BMD of the lumbar spine, femoral neck, and total hip was used to diagnose osteoporosis (T-score ≤−2.5). Sarcopenia was defined by low handgrip strength (<26 kg for men; <18 kg for women) and low muscle mass (<7.0 kg/m2 for men; <5.7 kg/m2 for women). Patients who met cutoffs for both osteoporosis and sarcopenia were considered to have osteosarcopenia. Logistic regression was performed to identify correlates of sarcopenia and osteoporosis.
The study cohort included 117 patients (82.1% women). Median age at PBC diagnosis was 61 years (interquartile range [IQR], 51-69 years). Of 117 patients, 33 had osteoporosis (28.2%), 27 had sarcopenia (23.1%), 21 had vertebral fracture (17.9%), and 18 had osteosarcopenia (15.4%).
In multivariate analyses, osteoporosis was significantly associated with older age (odds ratio [OR] 1.090; 95% CI, 1.034-1.148; P =.001), lower body mass index (OR 0.823; 95% CI, 0.690-0.982; P =.031), and sarcopenia (OR 4.126; 95% CI, 1.280-13.297; P =.018). Similarly, sarcopenia diagnosis was significantly associated with osteoporosis (OR 3.420; 95% CI, 1.057-11.067; P =.040), lower body mass index (OR 0.708; 95% CI, 0.568-0.883; P =.002), and vertebral fracture (OR 10.936; 95% CI, 2.678-44.663; P =.001).
These trends persisted in analyses stratified by gender. In women, sarcopenia diagnosis increased the likelihood of osteoporosis (OR 6.510; 95% CI, 2.100-20.180; P =.001). Similarly, osteoporosis was significantly predictive of sarcopenia in women (OR, 4.012; 95% CI, 1.186-13.576; P =.020). Skeletal muscle mass index was significantly positively correlated with BMD of the lumbar spine, femoral neck, and total hip (all P <.001). Compared with patients with neither condition, patients with osteosarcopenia had significantly higher prevalence of vertebral fracture (55.6% vs 6.7%).
While it is well-known that PBC increases susceptibility to osteoporosis, the present data elucidate correlations between PBC, osteoporosis, and sarcopenia. Patients with osteoporosis and sarcopenia were more likely to be complicated by vertebral fracture. As study limitations, investigators cited the cross-sectional design, which prevents the assertion of causality. Additionally, patient lifestyle and nutrition data were not available.
“[O]steoporosis and sarcopenia are critical issues, especially in postmenopausal female patients,” the investigators concluded. “Comprehensive diagnostic assessment and treatment strategies for these bone and muscle disorders are essential inpatients [with PBC].”
Saeki C, Oikawa T, Kanai T, et al. Relationship between osteoporosis, sarcopenia, vertebral fracture, and osteosarcopenia in patients with primary biliary cholangitis [published online June 16, 2020]. Eur J Gastroenterol Hepatol. doi: 10.1097/MEG.0000000000001791