An analysis of age-related loss of skeletal muscle mass and its significance on osteoarthritis in a Korean population

BACKGROUND/AIMS: This study was conducted in order to analyze the effects of sarcopenia on age-related osteoarthritis (OA) of the knee in a Korean population. METHODS: All the Korean subjects who visited the Yeungnam University Medical Center Health Promotion Center between 2008 and 2012 in order to undergo a routine medical examination were enrolled. A total of 5,723 young, healthy people (2,959 males, 2,764 females) enrolled as normal subjects and 23,473 subjects (13,006 males and 10,467 females) were included for evaluation of the effects of sarcopenia on OA. There were 266 subjects who followed-up bioelectrical impedance analysis at a 4-year interval. Of 327 subjects enrolled in this study, knees with anteroposterior X-rays were assessed according to the Kellgren-Lawrence (K/L) grade. RESULTS: Skeletal muscle mass index (SMI) and basal metabolic rate (BMR) showed a steady decrease with the advance of age (p < 0.01), but SMI showed strong positive correlation with BMR (r = 0.72, β = 30.96, p < 0.01). During the 4-year interval, BMR showed a significant decrease with aging (p < 0.01), consistently with the decrease of SMI. Knees with normal SMI were prone to be designated as K/L grade 0 or 1; however, subjects with sarcopenia showed a trend toward the higher K/L grade, classified as knee radiological osteoarthritis (ROA) (p < 0.01). CONCLUSIONS: The results of this study may indicate that sarcopenia as age-related loss of skeletal muscle mass is interactively correlated with the presence and severity of age-related OA.

An overlap syndrome of Churg-Strauss syndrome and rheumatoid arthritis / 영남의대학술지

Churg-Strauss syndrome (CSS) is a necrotizing vasculitis with extra-, peri-vascular eosinophilic infiltration. Chronic symmetric polyarthritis with the presence of rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody are the mainstay of rheumatoid arthritis (RA) diagnosis. Mononeuritis multiplex is a peripheral neuropathy involving more than 2 separate nerve areas. A 62-year-old male patient was referred for left foot drop and polyarthritis of both hands and feet for 4 months. During evaluation, mononeuritis multiplex was detected on nerve conduction study and electromyography tests: vasculitis with neutrophil, eosinophil, and lymphocyte infiltration on peroneal nerve biopsy. A positive response to methacholin and bronchodilator was observed on the pulmonary function test. Radiologic tests showed peri-articular soft tissue swelling and osteopenia on both hand and foot. Marked peripheral eosinophilia, high RF, and positive perinuclear anti-neutrophil cytoplasmic antibody were detected on blood tests. Here, we report on a patient with overlap syndrome of CSS and RA with review of the relevant literature, from which a few references to overlap syndrome of CSS and RA were available.