Background: During the coronavirus disease 2019 (COVID-19) pandemic, people in Japan were urged to stay at home as much as possible, and this resulted in significant changes in lifestyle behavior. The new lifestyle included factors affecting both energy intake and energy consumption, and it is now thought that weight gain during the lockdown was the result of complex effects. The aim of this study was to determine the relationships among lifestyle habits, laboratory data, and body weight gain during the lockdown using medical check-up data. Methods: A total of 3789 individuals who had undergone consecutive medical check-ups during the period from 2018 to 2020 were included in this study. Participants whose body weight had increased by 5% or more were divided into two groups: a before-lockdown group (participants who had gained weight between 2018 and 2019) and an after-lockdown group (participants who had gained weight between 2019 and 2020). Physical measurements, laboratory data, and answers to six questions about lifestyle habits, for which information was obtained from the records from medical check-ups, were compared in the two groups. Results: There was no significant difference between the distribution of weight changes in 2018–2019 before the lockdown and the distribution of weight changes in 2019–2020 after the lockdown. The before-lockdown and after-lockdown groups both included about 7% of the total participants (279 and 273 participants, respectively). Diastolic blood pressure and levels of AST, ALT, and LDL-C were significantly higher in the after-lockdown group than in the before-lockdown group. The percentages of participants with alcohol consumption and exercise habits were significantly higher in the after-lockdown group than in the before-lockdown group, and an analysis by gender showed that the differences were significant for women but not for men. Conclusions: The distributions of weight changes before and during the COVID-19 pandemic were similar. Exercise habits and alcohol consumption might have been unique factors causing weight gain during the COVID-19 pandemic, particularly in women. Our findings suggest that the impact of behavioral restrictions and lifestyle changes during a pandemic may be different in men and women.

Fibroblast growth factor receptor 1 (FGFR1), also known as KAL2, is a tyrosine kinase receptor, and variants of FGFR1 have been detected in patients with Kallmann syndrome (KS), which is a congenital developmental disorder characterized by central hypogonadism and anosmia. Herein, we report an adult case of KS with a novel variant of FGFR1. A middle-aged male was referred for a compression fracture of a lumbar vertebra. It was shown that he had severe osteoporosis, anosmia, gynecomastia, and a past history of operations for cryptorchidism. Endocrine workup using pituitary and gonadal stimulation tests revealed the presence of both primary and central hypogonadism. Genetic testing revealed a novel variant of FGFR1 (c.2197_2199dup, p.Met733dup). To identify the pathogenicity of the novel variant and the clinical significance for the gonads, we investigated the effects of the FGFR1 variant on the downstream signaling of FGFR1 and gonadal steroidogenesis by using human steroidogenic granulosa cells. It was revealed that the transfection of the variant gene significantly impaired FGFR1 signaling, detected through the downregulation of SPRY2, compared with that of the case of the forced expression of wild-type FGFR1, and that the existence of the variant gene apparently altered the expression of key steroidogenic factors, including StAR and aromatase, in the gonad. The results suggested that the novel variant of FGFR1 detected in the patient with KS was linked to the impairment of FGFR1 signaling, as well as the alteration of gonadal steroidogenesis, leading to the pathogenesis of latent primary hypogonadism.

Long COVID (LC) may involve endocrine dysfunction; however, the underlying mechanism remains unclear. To examine hypothalamic–pituitary responses in patients with LC, we conducted a single-center retrospective study of patients with refractory LC referred to our University Hospital who underwent anterior pituitary stimulation tests. Between February 2021 and November 2025, 1251 patients with long COVID were evaluated, of whom 207 (19%) had relatively low random ACTH or cortisol levels. Ultimately, 16 underwent anterior pituitary stimulation tests and were included. All tests were performed in an inpatient setting without exogenous steroids. Fifteen patients (six women, mean age 35.6 years) underwent corticotropin-releasing hormone (CRH), thyrotropin-releasing hormone (TRH), and gonadotropin-releasing hormone (GnRH) tests. All patients had mild acute COVID-19, eight had ≥2 vaccinations, and the mean interval from infection was 343 days. Frequent symptoms included fatigue (100%), insomnia (66.7%), headache (60.0%), anorexia/nausea (40.0%), and brain fog (40.0%). Mean early-morning cortisol and 24 h urinary free cortisol were 7.5 μg/dL and 41.0 μg/day, respectively. MRI showed an empty sella in one case. Peak hormonal responses were preserved (ΔACTH 247%, ΔTSH 918%, ΔPRL 820%, ΔFSH 187%, ΔLH 1150%); however, peaks were delayed beyond 60 min in ACTH (13%), LH (33%), and FSH (87%). Notably, significantly delayed elevations remained at 120 min in the responses of TSH (4.1-fold), PRL (1.8-fold), LH (9.3-fold), and FSH (2.8-fold), suggesting possible hypothalamic involvement, particularly in the gonadotropin responses. Additionally, serum IGF-I was lowered (−0.70 SD), while GH response (mean peak 35.5 ng/mL) was preserved by growth hormone-releasing peptide (GHRP)-2 stimulation. Low-dose hydrocortisone and testosterone were initiated for three patients. Although direct viral effects and secondary suppression have been proposed, our findings may suggest that, at least in part, the observed response characteristics are consistent with functional secondary hypothalamic dysfunction rather than irreversible primary injury. These findings highlight the need for objective endocrine evaluation before initiating hormone replacements.

: Paragonimiasis is a parasitic disease caused by the genus Paragonimus , typically transmitted through the ingestion of raw or undercooked freshwater crabs. Although pulmonary involvement is typical, ectopic migration to subcutaneous or hepatic sites is rare and poses diagnostic challenges. A case of paragonimiasis in a 29-year-old Cambodian woman residing in Japan who presented with painless subcutaneous nodules on the chest and abdomen is reported in the current study. She had consumed raw crab 4 months before presentation. Laboratory findings revealed marked eosinophilia (21,000/ µ L) and elevated immunoglobulin E (5,049 IU/mL). Computed tomography scans revealed pleural effusion, club-shaped pulmonary consolidation, funicular hypodense lesions in the liver, and subcutaneous lesions. Stool and sputum test results were negative for parasite eggs; however, a microplate ELISA indicated a Paragonimus westermani infection. The patient responded well to 3 consecutive days of praziquantel (75 mg/kg/day) and was discharged a week later. This case highlights the importance of considering paragonimiasis in patients with unexplained subcutaneous nodules and eosinophilia, especially when supported by dietary risk factors.

Background: Although several risk factors have been reported for long COVID (LC), reliable biomarkers for this illness remain lacking. Insulin-like growth factor (IGF)-I, a major mediator of growth hormones, plays an important role in metabolism, neuroprotection, and systemic homeostasis, and therefore may be useful in predicting the severity and prognosis of LC. Methods: This study included patients who visited a specialized clinic for long COVID between 2022 and 2025 during the Omicron period and had serum IGF-I measurements taken. IGF-I levels were expressed as age- and sex-adjusted standard deviation scores (IGF-I SD), and patients were classified into low (SD < −1.0), normal (−1.0 ≤ SD < 1.0), and high (SD ≥ 1.0) groups. Clinical characteristics, patient-reported outcomes, laboratory data, and follow-up duration were analyzed. Results: A total of 811 patients were included (median 42 years; 52.5% female). Compared with the normal group, the low-IGF-I group exhibited higher fatigue (FAS: 37.0 vs. 34.0; p < 0.05) and depressive (SDS: 50.0 vs. 49.0; p < 0.05) status. Multivariable linear regression analyses identified lower IGF-I SD as independently associated with higher scores of both FAS and SDS. IGF-I SD values showed negative correlations with ferritin (ρ = −0.125, p < 0.05) and TSH (ρ = −0.202, p < 0.01) and positive correlations with albumin (ρ = 0.227, p < 0.01) and FT4 (ρ = 0.165, p < 0.01). Among the 237 patients who completed follow-up, the median duration from the initial visit to recovery tended to be longer in the low-IGF-I group (221 days) compared with the normal (191 days) and high (109 days) groups, although these differences were not statistically significant overall. In patients aged < 50 years, the low-IGF-I group showed a relatively longer follow-up duration (p < 0.05). Furthermore, the low-IGF-I group had a longer time to recovery compared to the high-IGF-I group (p < 0.05), and this difference was more pronounced in patients under 50 years of age, with significant differences observed among the three IGF-I groups. Conclusions: Lower IGF-I levels in LC may be associated with greater fatigue and depressive symptoms and longer recovery time, particularly in younger patients. Further studies are needed to clarify the clinical significance of these findings.