Osteoporosis is characterized by a decline in bone mineral density (BMD) and increased fracture risk. Free radicals and antioxidant systems play a central role in bone remodeling. This study was conducted to illustrate the role of oxidative-stress-related genes in BMD and osteoporosis. A systematic review was performed following the PRISMA guidelines. The search was computed in PubMed, Web of Sciences, Scopus, EBSCO, and BVS from inception to November 1st, 2022. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Checklist tool. A total of 427 potentially eligible articles exploring this search question were detected. After removing duplicates (n = 112) and excluding irrelevant manuscripts based on screenings of their titles and abstracts (n = 317), 19 articles were selected for full-text review. Finally, 14 original articles were included in this systematic review after we applied the exclusion and inclusion criteria. Data analyzed in this systematic review indicated that oxidative-stress-related genetic polymorphisms are associated with BMD at different skeletal sites in diverse populations, influencing the risk of osteoporosis or osteoporotic fracture. However, it is necessary to look deep into their association with bone metabolism to determine if the findings can be translated into the clinical management of osteoporosis and its progression.

Coronavirus disease (COVID-19) is an infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can be asymptomatic or present with multiple organ dysfunction. Many infected individuals have chronic alterations associated with neuropsychiatric, endocrine, gastrointestinal, and musculoskeletal symptoms, even several months after disease onset, developing long-COVID or post-acute COVID-19 syndrome (PACS). Microbiota dysbiosis contributes to the onset and progression of many viral diseases, including COVID-19 and post-COVID-19 manifestations, which could serve as potential diagnostic and prognostic biomarkers. This review aimed to discuss the most recent findings on gut microbiota dysbiosis and its relationship with the sequelae of PACS. Elucidating these mechanisms could help develop personalized and non-invasive clinical strategies to identify individuals at a higher risk of experiencing severe disease progression or complications associated with PACS. Moreover, the review highlights the importance of targeting the gut microbiota composition to avoid dysbiosis and to develop possible prophylactic and therapeutic measures against COVID-19 and PACS in future studies.

Recent evidence shows that obesity correlates negatively with bone mass. However, traditional anthropometric measures such as body mass index could not discriminate visceral adipose tissue from subcutaneous adipose tissue. The visceral adiposity index (VAI) is a reliable sex-specified indicator of visceral adipose distribution and function. Thus, we aimed to identify metabolomic profiles associated with VAI and low bone mineral density (BMD). A total of 602 individuals from the Health Workers Cohort Study were included. Forty serum metabolites were measured using the targeted metabolomics approach, and multivariate regression models were used to test associations of metabolomic profiles with anthropometric, clinical, and biochemical parameters. The analysis showed a serum amino acid signature composed of glycine, leucine, arginine, valine, and acylcarnitines associated with high VAI and low BMD. In addition, we found a sex-dependent VAI in pathways related to primary bile acid biosynthesis, branched-chain amino acids, and the biosynthesis of pantothenate and coenzyme A (CoA). In conclusion, a metabolic profile differs by VAI and BMD status, and these changes are gender-dependent.

In postmenopausal women, due to endocrine changes, there is an increase in oxidative stress (OS) that predisposes them to cardiovascular and metabolic alterations. Sixty-one percent of women in this stage require a primary therapeutic strategy to decrease OS. This study aimed to evaluate the effect of resveratrol and vitamin C on OS in postmenopausal women. A randomized, double-blind clinical trial was carried out. Forty-six postmenopausal women with insulin resistance (HOMA-IR > 2.5) were included and divided into three treatment groups: group A: resveratrol, n = 13; group B: resveratrol + vitamin C, n = 15; and group C: vitamin C, n = 14. Between before and after the antioxidants, group B showed a decrease of 33% in lipohydroperoxides (p = 0.02), and malondialdehyde (MDA) decreased by 26% (p = 0.0007), 32% (p = 0.0001), and 38% (p = 0.0001) in groups A–C, respectively. For protein damage, group B is the most representative, with a decrease of 39% (p = 0.0001). For total antioxidant capacity (TAC), there were significant increases of 30% and 28% in groups B and C, respectively. For HOMA-IR, there were no significant differences among the study groups. Supplementation with this combination of antioxidants significantly decreases markers of OS in postmenopausal women. In addition, it increases TAC by up to 30%.

Background: Inconsistent epidemiological evidence between uric acid (UA) and bone mineral density (BMD) has been observed. Therefore, we evaluated the association between UA and BMD in Mexican adults. Methods: This analysis was conducted on 1423 participants from the Health Workers Cohort Study. We explored cross-sectional associations using linear regression and longitudinal associations using fixed-effects linear regression by sex and age groups (<45 and ≥45 years). Results: In females <45 years old, the cross-sectional analysis showed that UA levels were positively associated with total hip BMD. However, in the longitudinal analysis, we observed a negative association with the femoral neck and lumbar spine BMD. In contrast, in males <45 years old, we found an increase in total hip and femoral neck BMD in the groups with high levels of UA in the longitudinal association. On the other hand, in females ≥45 years old, we observed a longitudinal association between UA and loss of BMD at different sites. We did not observe an association between UA levels and BMD in males ≥45 years old. Conclusions: Our results suggest higher serum UA levels are associated with low BMD at different skeletal sites in Mexican females. Further studies are needed to delineate the underlying mechanisms behind this observation.

Epidemiological studies suggest a relationship between total 25-hydroxyvitamin D [25(OH)D], adiposity, and metabolic traits. The bioavailability of 25(OH)D is regulated by the albumin, vitamin D binding protein (VDBP), and variants of the GC gene. Therefore, it is not clear if bioavailable or free 25(OH)D offer additional benefits compared to total 25(OH)D when estimating the magnitude of these associations. Our aim was to evaluate the association between 25(OH)D (total, free and bioavailable) with adiposity and metabolic traits. This was a cross-sectional study of 1904 subjects from the Health Workers Cohort Study from Mexico. Free and bioavailable 25(OH)D were calculated based on VDBP and albumin determinations, using a formula adjusted for the GC gene diplotypes. Adiposity and metabolic traits were measured with standardized procedures. Free and bioavailable 25(OH)D levels correlated with total 25(OH)D, r = 0.71 and 0.70, respectively (p < 0.001). Total, bioavailable and free 25(OH)D levels were negatively associated with the adiposity marker (visceral adiposity index) and metabolic traits (metabolic syndrome, type 2 diabetes, triglycerides, triglycerides/HDL-c ratio, and triglycerides/glucose index) in multivariate regression models (ORs = 0.73 to 0.96). Our findings suggest that free and bioavailable 25(OH)D do not offer additional advantages over total 25(OH)D regarding its association with adiposity and several metabolic traits in Mexican adults.