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Background: Vitamin D is a fat-soluble steroid that influences cardiovascular health by affecting lipid metabolism. Since dyslipidemia is a key risk factor for cardiovascular disease (CVD), our study aimed to explore the relationship between vitamin D levels and lipid parameters, considering the effects of age and gender. Methods: In this cross-sectional study of 47,778 outpatients, we analyzed correlations between two forms of vitamin D—25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D)—and lipid parameters, including low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol (TC). Subgroup analyses by age and gender provided additional insights. Results: Results showed that 25(OH)D levels were negatively correlated with LDL and TC across the cohort. This association was particularly evident in men over 50, whereas women showed a positive correlation with LDL and TC before age 50 and a negative correlation after. HDL levels positively correlated with 25(OH)D across all age groups, with the strongest association in postmenopausal women. In contrast, 1,25(OH)2D showed a positive correlation only with HDL in individuals over 50, with no significant correlation with LDL or TC in any age group. Conclusions: In conclusion, findings from this cross-sectional study underscore an association between elevated levels of 25(OH)D and more favorable lipid profiles, characterized by reduced LDL and total cholesterol, as well as increased HDL levels. This association is particularly pronounced among individuals over 50 years of age and postmenopausal women. [ABSTRACT FROM AUTHOR]

Metallic implants are frequently used in medicine to support and replace degenerated tissues. Implant loosening due to particle exposure remains a major cause for revision arthroplasty. The exact role of metal debris in sterile peri‐implant inflammation is controversial, as it remains unclear whether and how metals chemically alter and potentially accumulate behind an insulating peri‐implant membrane, in the adjacent bone and bone marrow (BM). An intensively focused and bright synchrotron X‐ray beam allows for spatially resolving the multi‐elemental composition of peri‐implant tissues from patients undergoing revision surgery. In peri‐implant BM, particulate cobalt (Co) is exclusively co‐localized with chromium (Cr), non‐particulate Cr accumulates in the BM matrix. Particles consisting of Co and Cr contain less Co than bulk alloy, which indicates a pronounced dissolution capacity. Particulate titanium (Ti) is abundant in the BM and analyzed Ti nanoparticles predominantly consist of titanium dioxide in the anatase crystal phase. Co and Cr but not Ti integrate into peri‐implant bone trabeculae. The characteristic of Cr to accumulate in the intertrabecular matrix and trabecular bone is reproducible in a human 3D in vitro model. This study illustrates the importance of updating the view on long‐term consequences of biomaterial usage and reveals toxicokinetics within highly sensitive organs. [ABSTRACT FROM AUTHOR]

Delayed type hypersensitivity (DTH) reactions are considered infrequent complications in arthroplasty, but have been recognized to be associated with devastating morbidity and substantial decrease in quality of life of affected patients. Chronic inflammation of artificial joints and associated loss of peri-implant bone often require revision surgery. Methods for the diagnosis of implant-related DTH are available but infrequently considered to the full extent. Sequential diagnostics based on exclusion of septic complications, local and systemic metal level determination, lymphocyte transformation testing (LTT), and local T cell subset analysis are required for an unequivocal DTH diagnosis. Here, we report on a patient with a history of chronic rheumatoid arthritis and an unfavorable outcome of unilateral knee arthroplasty. This case illustrates pitfalls and difficulties in the course of recurrent inflammation following joint replacement. In the early course, suspicion of low-grade bacterial infection led to three two-stage revisions. Afterwards, the joint was proven to be sterile. However, metal level quantification revealed release of especially cobalt and chromium from the joint, LTT indicated persisting cobalt and nickel sensitization and subset analysis of T cells from the synovium suggested DTH as a root cause for the inflammatory symptoms. This report aims to recommend the depicted diagnostic algorithm as an adequate tool for future DTH detection. Yet, systemic to local subset ratios for effector memory and regulatory T cells should be derived from sufficient patient numbers to establish it as a diagnostic marker. Moreover, future prospects regarding implant-related DTH diagnostics are discussed. Therapeutic options for the portrayed patient are proposed, considering pharmaceutical, cell-therapeutic and surgical aspects. Patients who experience peri-implant inflammation but do not have obvious mechanical or infectious problems remain a diagnostic challenge and are at high risk of being treated inadequately. Since potentially sensitizing materials are regularly used in arthroplasty, it is essential to detect cases of acute DTH-derived inflammation of an artificial joint at early postoperative stages. This would reduce the severity of inflammation-related long-term consequences for affected patients and may avoid unnecessary revision surgery. [ABSTRACT FROM AUTHOR]