BACKGROUND: Despite evidence from animal and clinical studies showing the detrimental effects of macrophage migration inhibitory factor (MIF) on bone metabolism, there are no clinical studies relating circulating MIF levels to osteoporosis-related phenotypes. This cross-sectional study investigated the association of plasma MIF with bone mineral density (BMD), bone turnover markers (BTMs), and prevalence of osteoporosis in postmenopausal Korean women. METHODS: A total of 246 women not taking any medications or diagnosed with any diseases that could affect bone metabolism were enrolled. BMD values at the lumbar spine, femoral neck, and total femur, and blood levels of MIF and BTMs were measured in all subjects. Osteoporosis was defined by World Health Organization criteria. RESULTS: Before and after adjustment for confounding variables, higher MIF levels were significantly associated with lower BMD values at all measured sites and higher levels of all BTMs. All BMD values and BTMs significantly changed in a dose-dependent fashion across increasing MIF quartile. When participants were divided into two groups according to osteoporosis status, postmenopausal women with osteoporosis demonstrated 24.2% higher plasma MIF levels than those without osteoporosis (P=0.041). The odds ratio per each standard deviation increment of MIF levels for prevalent osteoporosis was 1.32 (95% confidence interval, 1.01 to 1.73). CONCLUSION: This study provides the first epidemiological evidence that higher plasma MIF may be associated with higher risk of osteoporosis resulting from lower bone mass and higher bone turnover rate, and thus it could be a potential biomarker of poor bone health outcomes in postmenopausal women.
Animals ; Bone Density* ; Bone Remodeling* ; Confounding Factors (Epidemiology) ; Cross-Sectional Studies ; Female ; Femur ; Femur Neck ; Humans ; Macrophage Migration-Inhibitory Factors ; Macrophages* ; Metabolism ; Odds Ratio ; Osteoporosis ; Phenotype ; Plasma* ; Prevalence ; Spine ; World Health Organization

Purpose: We aimed to investigate changes in visiting patterns after the lifting of mask mandates in a single pediatric emergency medical center in Seoul, Korea. Methods: This retrospective study was based on the data of patients’ (≤ 18 years) visits to the emergency department (ED) of the center from January 1, 2022 through June 30, 2023. Clinical characteristics, Korean Triage and Acuity Scale (KTAS) level, ED outcomes, and length of stay were compared between before (March 20-June 30, 2022) and after (March 20-June 30, 2023) the lifting of mask mandates. The comparisons were iterated in the patients with infectious disease. Results: During the study period, a total of 18,654 children visited the ED. After the lifting of mask mandates, ED visits increased from 7,146 to 11,508 (61.0%; 95% confidence interval, 59.5-62.6; P < 0.001). The increase was more prominent in the age of 2-5 years (82.9%), infectious diseases (175.3%), KTAS level 3 (127.7%), and length of stay shorter than 3 hours (78.8%-92.6%). The number of patients per hour increased by 151.2% for 5 patients or more and over 3,000% for 10 or more. Median length of stay decreased (2.3 hours [interquartile range, 1.2-4.1] to 1.9 hours [1.1-3.5]; P < 0.001). The patients with infectious disease (n = 7,139) showed similar patterns of increase in the age of 2-5 years, KTAS level 3, and length of stay shorter than 3 hours, with an additional increase in the age of 6-18 years. Conclusion After the lifting of mask mandates, pediatric visits increased by 61%, with the highest increase in children with mild infectious diseases on weekends and at night, and the proportion of more than 10 visits per hour significantly increased. We need urgent and realistic support measures from health authorities.