Vitamin D status and its associations with bone mineral density, bone turnover markers, and parathyroid hormone in Chinese postmenopausal women with osteopenia and osteoporosis

Exploring the relationship between serum 25-hydroxyvitamin D levels and intestinal fungal communities and their metabolites in postmenopausal Chinese women

BACKGROUND

Research gaps persist in understanding the interactions between serum 25 (OH)D levels, intestinal fungi, and their metabolites in postmenopausal women.

METHODS

This study, approved by the Ethics Committee of Zhongshan Hospital, Xiamen University, recruited postmenopausal women from Xiamen. Clinical assessments included Body Mass Index (BMI) calculations and blood tests for various bone-related markers using Roche's electrochemiluminescence system. Bone density was measured via dual-energy X-ray absorptiometry. Fecal DNA was extracted for Internal Transcribed Spacer (ITS) sequencing with a two-stage PCR process and analyzed using high-throughput Illumina sequencing. Metabolites were extracted from fecal samples and analyzed by ultra-high-performance liquid chromatography combined with mass spectrometry. Statistical analyses and data visualization were performed using R, focusing on fungal community structure and correlations with metabolites.

RESULTS

The study analyzed 81 postmenopausal women, categorized into vitamin D deficient (VDD), insufficient (VDI), and sufficient (VDS) groups based on serum 25 (OH)D levels. Other health markers, including age and BMI, were consistent across groups. Notably, Linear discriminant analysis identified distinct fungal communities across VDD, VDI, and VDS groups. In the VDD group, notable fungi included Hanseniaspora occidentalis and Pichia. The VDI group showed enrichment of Candida, while the VDS group had higher abundances Such as Phanerochaete, and Nectriaceae. Alpha diversity metrics, such as the Chao1 index, differed significantly among the groups (p < 0.05). Correlation analysis (Spearman) revealed that fungi like Trichosporon and Penicillium positively associated with 25 (OH)D3, whereas fungi such as Cystofilobasidium were negatively correlated with bone mineral density (BMD). Metabolites like Glutaric acid positively correlated with 25 (OH)D3, while L-Citrulline and Deoxycholic acid were negatively correlated. Additionally, Argininosuccinic acid correlated positively with BMD, whereas Acamprosate and p-Hydroxyphenylacetic acid were negatively associated.

CONCLUSION

In postmenopausal women, fungal community composition varies significantly with vitamin D status, potentially correlating with serum 25 (OH)D levels and BMD, indicating that specific fungal species may be relevant for therapeutic strategies with osteoporosis and offering insights into the broader bone health effects of vitamin D.

Relationship Between Vitamin D Receptor Gene BsmI Polymorphism and 25-Hydroxyvitamin D Total Levels in Slovak Postmenopausal Women with Reduced Bone Mineral Density

Objectives: The BsmI polymorphism of the VDR gene (vitamin D receptor) is one of the important genetic variants influencing the development of osteoporosis. Measurement and evaluation of the 25-hydroxyvitamin D (25(OH)D) concentration in individuals with reduced bone mineral density are essential because deficiency of this hormone causes impaired bone mineralization, leads to low BMD (bone mineral density), and influences fracture formation. The aim of the study was to investigate the relationship between the VDR gene BsmI polymorphism and 25(OH)D levels in Slovak postmenopausal women. Materials and Methods: The study population consisted of 287 untreated postmenopausal women, who were divided into three groups based on T-scores: normal (CG = 65), osteopenia (OPE = 126), and osteoporosis (OPO = 96). DNA isolation was performed using a standard protocol. Genetic analyses of the BsmI (rs1544410) polymorphism of the VDR gene were performed using the TaqMan SNP genotyping assays. Biochemical analysis of total 25(OH)D was performed in blood serum using the electrochemiluminescence method. Results: The chi-square test confirmed that the mutant T allele was not associated with the development of osteoporosis (p = 0.419). Through Kruskal-Wallis analysis, we found significant differences (p < 0.05, p < 0.01) in total 25(OH)D concentrations in individual genotypes of the BsmI variant of the VDR gene between the groups of women studied. Conclusions: It can be concluded that the VDR gene and its variant BsmI as well as 25(OH)D total may be relevant markers in the etiology of the search for individuals at risk of osteoporosis.

The association of combined vitamin C and D deficiency with bone mineral density and vertebral fracture

PURPOSE

Both vitamin C and D deficiencies are extremely common in clinical practice, especially in elderly population. Unfortunately, the role of vitamin C deficiency in osteoporosis related consequences is often neglected. The aim of the present study is to analyse if combined vitamin C and D deficiency would have an association with bone mineral density (BMD) and osteoporotic vertebral fracture (OVF).

METHODS

Ninety-nine post-menopausal female patients admitted in the department of spine surgery of third affiliated hospital of Sun Yat-sen University were enrolled in the study. The participants were divided into four groups; vitamin D deficiency alone (comparator group), vitamin C deficiency alone and combined vitamin C and D deficiency as experimental group. The levels of vitamin C, vitamin D, calcium, phosphorous, BMD and condition of OVF were analysed.

RESULTS

There were statistically significant differences between the groups in terms of vitamin C and D levels. In terms of lumbar BMD, significant differences were observed between vitamin D deficiency alone and combined vitamin C and D deficiency. Only the combined vitamin C and D deficiency had a significant negative association with lumbar BMD and T-score. Similarly, combined vitamin C and D deficiency had a significant positive association with lumbar osteoporosis. None of the groups had any significant association with OVF. Combined vitamin C and D deficiency was found to be significantly associated with lower lumbar BMD and osteoporosis.

CONCLUSION

Combined vitamin C and D deficiency results in lower bone mineral density and higher risk of osteoporosis. We believe that existence of deficiencies of both vitamins could have a synergistic effect. Therefore, we recommend that vitamin C and D should be routinely measured in clinical practice.

Imiglucerase, cholecalciferol, and bone-diet in skeletal health management of type I Gaucher disease patients: a pilot study and systematic review

Skeletal anomalies represent a characteristic feature of type 1 Gaucher disease (GD1). Here we evaluated the impact of an integrated therapy comprising enzyme-replacement therapy (ERT), cholecalciferol, and a normocalcemic-normocaloric-hyposodic diet (bone diet) on bone health in GD1 patients. We also performed a systematic review to compare our results with available data. From January 1, 2015 to February 28, 2019, all GD1 patients referred to Federico II University were enrolled and treated with the integrated therapy. Bone turnover markers and bone mineral density (BMD) were evaluated at baseline (T0) and after 24 months (T24). We enrolled 25 GD1 patients, all showing 25-hydroxy vitamin D (25OHD) levels < 50 nmol/l (hypovitaminosis D) at T0. Response to cholecalciferol treatment was effective, showing a direct relationship between 25OHD levels before and after treatment. At T0, 2 GD1 patients showed fragility fractures, 5 the Erlenmeyer flask deformity, 3 osteonecrosis, and 7 a BMD Z-score ≤ -2. Overall, GD1 patients with bone anomalies showed higher C-terminal telopeptide levels compared with those without bone anomalies. No new bone anomalies occurred during 2 years of follow-up. At T24, BMD remained stable across the entire study cohort, including in patients with bone anomalies. The systematic review showed that our study is the first that evaluated all bone health parameters. Hypovitaminosis D is prevalent in GD1 patients. The response to cholecalciferol treatment was effective but different to healthy subjects and in patients with metabolic bone disorders. Integrated therapy including ERT, cholecalciferol, and bone diet guarantees bone health.

Osteoporosis and Primary Biliary Cholangitis: A Trans-ethnic Mendelian Randomization Analysis

Osteoporosis is a major clinical problem in many autoimmune diseases, including primary biliary cholangitis (PBC), the most common autoimmune liver disease. Osteoporosis is a major cause of fracture and related mortality. However, it remains unclear whether PBC confers a causally risk-increasing effect on osteoporosis. Herein, we aimed to investigate the causal relationship between PBC and osteoporosis and whether the relationship is independent of potential confounders. We performed bidirectional Mendelian randomization (MR) analyses to investigate the association between PBC (8021 cases and 16,489 controls) and osteoporosis in Europeans (the UK Biobank and FinnGen Consortium: 12,787 cases and 726,996 controls). The direct effect of PBC on osteoporosis was estimated using multivariable MR analyses. An independent replication was conducted in East Asians (PBC: 2495 cases and 4283 controls; osteoporosis: 9794 cases and 168,932 controls). Trans-ethnic meta-analysis was performed by pooling the MR estimates of Europeans and East Asians. Inverse-variance weighted analyses revealed that genetic liability to PBC was associated with a higher risk of osteoporosis in Europeans (OR, 1.040; 95% CI, 1.016-1.064; P = 0.001). Furthermore, the causal effect of PBC on osteoporosis persisted after adjusting for BMI, calcium, lipidemic traits, and sex hormones. The causal relationship was further validated in the East Asians (OR, 1.059; 95% CI, 1.023-1.096; P = 0.001). Trans-ethnic meta-analysis confirmed that PBC conferred increased risk on osteoporosis (OR, 1.045; 95% CI, 1.025-1.067; P = 8.17 × 10-6). Our data supports a causal effect of PBC on osteoporosis, and the causality is independent of BMI, calcium, triglycerides, and several sex hormones.