Association between Osteoporosis and Skeletal Muscle Mass in Men.

STUDY DESIGN: Cross-sectional study. PURPOSE: This cross-sectional study aimed to investigate the risk factors for osteoporosis in men by assessing bone mineral density (BMD), skeletal muscle mass, body fat mass, grip strength, and advanced glycation end products (AGEs). OVERVIEW OF LITERATURE: Fewer studies have reported the correlation between BMD and skeletal muscle mass in women. Moreover, a few studies have examined the relationship between osteoporosis and skeletal muscle mass. METHODS: This study included 99 men (mean age, 74.9 years; range, 28-93 years) who visited Qiball Clinic for BMD and body composition examinations. The osteoporosis group consisted of 24 patients (mean age, 72.5 years; range, 44-92 years), and the control group consisted of 75 individuals (mean age, 74.9 years; range, 28-93 years). Whole-body skeletal muscle mass was measured using a bioelectrical impedance analyzer. BMD was measured by dual X-ray absorptiometry. Skin autofluorescence (SAF), a marker of dermal AGE accumulation, was measured using a spectroscope. Osteoporosis was defined as a bone density T score of -2.5 or less. Physical findings, skeletal muscle mass, BMD, grip strength, and SAF were compared between the osteoporosis and control groups. RESULTS: The osteoporosis group had significantly lower trunk muscle mass (23.1 kg vs. 24.9 kg), lower leg muscle mass (14.4 kg vs. 13.0 kg), and skeletal mass index (7.1 kg/m2 vs. 6.7 kg/m2) than the control group (all p<0.05). Lower limb muscle mass was identified as a risk factor for osteoporosis in men (odds ratio, 0.64; p=0.03). CONCLUSIONS: Conservative treatment of osteoporosis in men will require an effective approach that facilitates the maintenance or strengthening of skeletal muscle mass, including exercise therapy with a focus on lower extremities and nutritional supplementation.

Analgesic Effect of Duloxetine on an Animal Model of Monosodium Iodoacetate-Induced Hip Osteoarthritis.

We investigated the efficacy of duloxetine on hyperalgesia, histopathological and radiographic findings, pain-related sensory innervation of dorsal-root ganglia (DRG), and spinal changes in a rat model of induced hip osteoarthritis (OA). The right hip joints of male Sprague-Dawley rats (n = 6 rats/group) in the Sham group were injected with 25 µl of sterile saline and 25 µl of sterile saline with 2 mg of monosodium iodoacetate (MIA) were injected to the MIA + Vehicle and MIA + Duloxetine groups. We injected duloxetine 20 mg/kg intraperitoneally in the MIA + Duloxetine group 28 days after injection, whereas rats in the MIA + Vehicle group were injected with 0.5 ml of 20% dimethyl sulfoxide. We assessed hyperalgesia, histopathological changes, immunoreactive (-ir) neurons for calcitonin gene-related peptide and activating transcription factor 3 in DRG, and immunoreactive neurons for ionized-calcium-binding adaptor molecule 1 (Iba1) in the dorsal horn of the spinal cord. MIA administration into the hip joint let to mechanical hyperalgesia of the ipsilateral hind paw (p < 0.05). A single injection of duloxetine significantly attenuated it in induced hip OA (p < 0.05) and suppressed the number of Iba1-ir microglia of the ipsilateral dorsal horn (p < 0.05). These results suggest that a single injection of duloxetine suppressed mechanical hyperalgesia and may influence the expression of Iba1 in the microglia of the ipsilateral dorsal horn in the MIA-induced hip OA. This finding implies the inhibitory effects of duloxetine against neuropathic pain, which may lead to a change of microglial activities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:422-430, 2020.

Analysis of skeletal muscle mass in women over 40 with degenerative lumbar scoliosis.

PURPOSE: We investigated the involvement of sarcopenia in middle-aged and elderly women with degenerative lumbar scoliosis (DLS). METHODS: A total of 971 women (mean age 70.4 years) were included in our study. These included 87 cases of DLS (mean 73.8 years) and 884 controls (69.8). Lumbar and femur BMD was measured for all participants using dual-energy X-ray absorptiometry. We used a bioelectrical impedance analyzer to analyze body composition, including appendicular skeletal muscle mass index (SMI; appendicular lean mass (kg)/(height (m))2. We determined bone density and skeletal muscle mass in both groups and determined the prevalence of sarcopenia. We examined the correlation between bone density and appendicular muscle mass in both groups. We also examined factors related to scoliosis using logistic regression analysis. RESULTS: The DLS group showed significantly higher lumbar BMD, lower femur BMD, lower lean mass arm, and lower lean mass leg, and lower lean mass trunk (p < 0.05). Sarcopenia prevalence (SMI < 5.75) was 59.8% in DLS subjects and 42.8% in controls, revealing a high prevalence in DLS (p < 0.05). In both groups, lumbar and femur BMD were positively correlated with appendicular muscle mass. By logistic regression analysis, trunk muscle mass was detected as a risk factor for DLS independent of age (p < 0.05). CONCLUSIONS: In middle-aged and elderly women, prevalence of sarcopenia was 59.8% in DLS cases and 42.8% in controls, which revealed a high prevalence in DLS. A decrease in trunk muscle was a significant risk factor for DLS that was independent of age. These slides can be retrieved under Electronic Supplementary Material.

Changes in proinflammatory cytokines, neuropeptides, and microglia in an animal model of monosodium iodoacetate-induced hip osteoarthritis.

The aim of this study was to investigate the local production of proinflammatory cytokines, pain-related sensory innervation of dorsal-root ganglia (DRG), and spinal changes in a rat model of induced hip osteoarthritis (OA). Seventy-five Sprague-Dawley rats were used, including 25 controls and 50 injected into the right hip joints (sham group, injected with 25 µl of sterile saline: N = 25; and monosodium iodoacetate (MIA) group, injected with 25 µl of sterile saline with 2 mg of MIA: N = 25). We measured the local production of TNF-α, immunoreactive (-ir) neurons for calcitonin gene-related peptide (CGRP), and growth associated protein-43 (GAP-43) in DRG, and immunoreactive neurons for ionized-calcium-binding adaptor molecule-1 (Iba-1) in the dorsal horn of spinal cord, on post-induction days 7, 14, 28, 42, and 56 (N = 5 rats/group/time point). For post-induction days 7-42, the MIA group presented significantly elevated concentrations of TNF-α than the other groups (p < 0.01), and a higher expression of CGRP-ir in FG-labeled DRG neurons than the sham group (p < 0.01). MIA rats also presented significantly more FG-labeled GAP-43-ir DRG neurons than the sham group on post-induction days 28, 42, and 56 (p < 0.05), and a significantly higher number of Iba-1-ir microglia in the ipsilateral dorsal horn than the other groups, on post-induction days 28, 42, and 56. The results suggest that in rat models, pain-related pathologies due to MIA-induced hip OA, originate from inflammation caused by cytokines, which leads to progressive, chronic neuronal damage that may cause neuropathic pain. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2978-2986, 2018.

Surgical management of severe scoliosis with high-risk pulmonary dysfunction in Duchenne muscular dystrophy.

Between 2005 and 2007, 14 patients who had severe scoliosis in Duchenne muscular dystrophy (DMD) and a poor forced vital capacity (FVC) of <30% at admission underwent scoliosis surgery. FVC on admission was 21.6% (range, 16-27%). The patients were given respiratory muscle training using a pulmonary trainer (Threshold IMT, Philips Respironics, Inc.) for six weeks before operation. FVC increased to 26.2% (range, 22-31%) the day before operation. The mean preoperative scoliosis was 98 degrees (range, 81 degrees-130 degrees). All patients underwent posterior fusion and all-screw construction and were extubated on the operative day. No patients developed any respiratory complications. The postoperative scoliosis was 34 degrees (range, 20 degrees-40 degrees) (65%). FVC remained stable at six weeks after operation. FVC decreased to 19.8% (range, 16-25%) and the mean scoliosis was 35 degrees (range, 23 degrees-40 degrees) (64%) at two years after operation. DMD patients with severe scoliosis and FVC considered too low to permit reasonable surgical risk could undergo surgery and could benefit from surgery.