Fibroblast growth factor 21 (FGF21), a member of the FGF subfamily, is produced primarily in the liver and adipose tissue. The main function of FGF21 is to regulate energy metabolism of carbohydrates and lipids in the body through endocrine and other means, making FGF21 have potential clinical value in the treatment of metabolic disorders. Although FGF21 and its receptors play a role in the regulation of bone homeostasis through a variety of signaling pathways, a large number of studies have reported that the abuse of FGF21 and its analogues and the abnormal expression of FGF21 in vivo may be associated with bone abnormalities. Due to limited research information on the effect of FGF21 on bone metabolism regulation, the role of FGF21 in the process of bone homeostasis regulation and the mechanism of its occurrence and development have not been fully clarified. Certainly, the various roles played by FGF21 in the regulation of bone homeostasis deserve increasing attention. In this review, we summarize the basic physiological knowledge of FGF21 and the effects of FGF21 on metabolic homeostasis of the skeletal system in animal and human studies. The information provided in this review may prove beneficial for the intervention of bone diseases.

Purpose: A systematic review and meta-analysis was conducted to combine the data available from clinical trials and evaluate the clinical efficacy and safety of tirzepatide in people with type 2 diabetes (T2D).Methods: We systematically searched the MEDLINE, Embase, Cochrane Library, and clinical trials registries (https://clinicaltrials.gov) up to 25 March 2022 for randomized controlled trials (RCTs) that compared tirzepatide with placebo or active hypoglycemic drugs in subjects with T2D. Heterogeneity was judged by the I² value and Cochran’s Q test. The randomized effects model was adopted to calculate risk ratios and weighted mean differences (WMDs). The primary outcome was the change from baseline in HbA1c levels. Secondary efficacy endpoints were fasting serum glucose (FSG), change of body weight, blood pressure, fasting lipid profiles, and safety indexes.Results: Six trials comprising 6,579 subjects (4,410 in the tirzepatide group and 2,054 in the control group) fulfilled the pre-specified criteria and were included in the study. Tirzepatide treatment resulted in reducing HbA1c (WMD: -1.07%; 95% confidence intervals [CIs]: −1.44, −0.56), FSG (WMD, −21.50 mg/dl; 95% CI: −34.44, −8.56), body weight (WMD: −7.99 kg; 95% CI −11.36, −4.62), and blood pressure and ameliorated fasting lipid profiles, without increasing hypoglycemia, either as monotherapy or an add-on therapy. Tirzepatide increased the risk of gastrointestinal adverse events mainly in add-on therapy but not in terms of pancreatitis or cholelithiasis. Furthermore, tirzepatide presented a dose–response effect on the reduction in HbA1c and body weight and increase in nausea and vomiting.Conclusion: In patients with type 2 diabetes, tirzepatide shows superior blood glucose control and weight loss performance, without an increased risk of hypoglycemia.Systematic Review Registration: (https://www.crd.york.ac.uk/PROSPERO), identifier (CRD42022319442).

Objective: The aim of this study was to investigate the status of Vitamin D deficiency and the effect of environmental factors on Vitamin D levels so as to provide theoretical support for public health promotion in this region. Methods: A total of 22,387 subjects who underwent a physical examination at the center in the West China Hospital, Sichuan University, between April, 2018 and May, 2020 were enrolled in this study. Their data on gender, age, inspection date, serum 25 hydroxyvitamin D (25-(OH) D), parathyroid hormone (PTH), and total calcium were retrospectively reviewed. Next, the percentage of Vitamin D status was compared in different sex and age groups, and the fluctuation of Vitamin D level was described in relation to the change of environment. Finally, the univariable and multivariable linear regression analyses were performed to explore the risk and protective factors of Vitamin D deficiency. Results: The proportion of Vitamin D deficiency in this area was 42.17%, and it was significantly higher among women and young people. The fluctuation trend of 25-(OH) D levels are consistent with temperature and solar radiation, and opposite to air quality, in the whole year. There was a positive relationship between 25-(OH) D levels with temperature and solar radiation; however, parathyroid hormone, female and AQI were negatively correlated with Vitamin D levels. Conclusion: Vitamin D deficiency is common in subtropic areas, such as Sichuan Basin, which is related to solar radiation and air pollution.