A case of hypophosphatemia and elevated intact fibroblast growth factor 23 levels after short-term saccharated ferric oxide administration in a young woman and database analysis of adverse drug reactions in Japan.

Intravenous iron replacement therapy is a common treatment for iron deficiency. Commonly used agents in this treatment include ferric carboxymaltose, ferric derisomaltose, and saccharated ferric oxide (SFO). These drugs are known to elevate fibroblast growth factor 23 levels, resulting in hypophosphatemia, but in past reports, hypophosphatemia attributable to SFO treatment has been associated mainly with prolonged administration over several weeks. The present study details our experience of a case of moderate hypophosphatemia (<2 mg/dL) in a 22-year-old woman who had no specific history of hypophosphatemia during the first 5 days of SFO treatment, and showed an increase in intact fibroblast growth factor 23 levels within the first week of treatment. Cases of hypophosphatemia have been reported as occurring as early as 1 week after the start of SFO administration in the Japanese Adverse Drug Event Report database. These cases, along with our case, underline the need for awareness of the possibility of hypophosphatemia from the early stage of SFO administration, regardless of the patient's age or dosage, as well as the need to monitor patients to prevent complications.

Skeletal muscle is associated with exercise tolerance evaluated by cardiopulmonary exercise testing in Japanese patients with chronic obstructive pulmonary disease.

Decreasing exercise tolerance is one of the key features related to a poor prognosis in patients with chronic obstructive pulmonary disease (COPD). Cardiopulmonary exercise testing (CPET) is useful for evaluating exercise tolerance. The present study was performed to clarify the correlation between exercise tolerance and clinical parameters, focusing especially on the cross-sectional area (CSA) of skeletal muscle. The present study investigated 69 patients with COPD who underwent CPET. The correlations between oxygen uptake ([Formula: see text]) at peak exercise and clinical parameters of COPD, including skeletal muscle area measured using single-section axial computed tomography (CT), were evaluated. The COPD assessment test score (ρ = - 0.35, p = 0.02) was weakly correlated with [Formula: see text] at peak exercise. In addition, forced expiratory volume in one second (FEV1) (ρ = 0.39, p = 0.0009), FEV1/forced vital capacity (ρ = 0.33, p = 0.006), and the CSA of the pectoralis muscles (PMs) (ρ = 0.36, p = 0.007) and erector spinae muscles (ECMs) (ρ = 0.39, p = 0.003) were correlated with [Formula: see text] at peak exercise. Multivariate analysis adjusted by age and FEV1 indicated that PMCSA was weakly correlated after adjustment (ß value [95% confidence interval] 0.175 [0.03-0.319], p = 0.02). In addition, ECMCSA tended to be correlated, but not significantly after adjustment (0.192 [- 0.001-0.385] p = 0.052). The COPD assessment test, FEV1, FEV1/FVC, PMCSA, and ECMCSA were significantly correlated with [Formula: see text] at peak exercise.