Impact of treatment with active vitamin D calcitriol on bone turnover markers in people with type 2 diabetes and stage 3 chronic kidney disease

Gut-X Axis and Its Role in Poultry Bone Health: A Review

The normal development and growth of bones are critical for poultry health. With the rapid increase in poultry growth rates achieved over the last few decades, juvenile meat-type poultry exhibit a high incidence of leg weakness and lameness. These issues are significant contributors to poor animal welfare and substantial economic losses. Understanding the potential etiology of bone problems in poultry will aid in developing treatments for bone diseases. The gut microbiota represents the largest micro-ecosystem in animals and is closely related to many metabolic disorders, including bone disease. It achieves this by secreting secondary metabolites and coordinating with various tissues and organs through the circulatory system, which leads to the concept of the gut-X axis. Given its importance, modulating gut microbiota to influence the gut-X axis presents new opportunities for understanding and developing innovative therapeutic approaches for poultry bone diseases. In light of the extensive literature on this topic, this review focuses on the effects of gut microbiota on bone density and strength in poultry, both directly and indirectly, through the regulation of the gut-X axis. Our aim is to provide scientific insights into the bone health problems faced by poultry.

Correlation between diabetes mellitus and refracture risk in patients with osteoporotic fractures: a retrospective cohort study

BACKGROUND

Diabetes and osteoporosis are frequent long-term conditions. There is little information on the relationship between diabetes and the risk of refracture in people who have osteoporotic fractures (OPFs), even though both conditions have been individually associated with increased fracture risk.

METHODS

We conducted a retrospective cohort study using the Osteoporotic Fracture Registry System of the Affiliated Kunshan Hospital of Jiangsu University. The study included 2,255 patients aged 50 years or older who were admitted with OPFs, comprising 107 with diabetes and 2,148 without. The risk of refracture within 1, 3, and 5 years was evaluated using Cox proportional hazard regression models based on whether or not a diabetes diagnosis was made during the admission assessment. Furthermore, the rates of refracture between individuals with and without diabetes were compared using Kaplan-Meier curves.

RESULTS

In patients with OPFs, diabetes was significantly positively correlated with refracture risk. For the follow-up periods of 1, 3, and 5 years, the hazard ratios (HRs) in the fully adjusted model were 2.83 (95% confidence interval [CI]: 1.09 to 7.39, P-value = 0.033), 2.65 (95% CI: 1.27 to 5.52, P-value = 0.009), and 2.72 (95% CI: 1.39 to 5.32, P-value = 0.004), respectively.

CONCLUSIONS

The findings highlight the importance of monitoring bone health and implementing preventative interventions in individuals with diabetes, since they reveal that diabetic patients face a risk of refracture that is more than twice as high as that of non-diabetic individuals.

Vitamin D: are all compounds equal?

Vitamin D is a pre-hormone essential for maintaining mineral homeostasis and also plays significant roles in bone, cardiovascular and renal health. Vitamin D deficiency is prevalent in the general population, and even more so in chronic kidney disease (CKD) patients, in which it contributes to the development and progression of mineral and bone disorder. The landscape of vitamin D treatment has evolved, with several analogues now available, each possessing distinct pharmacokinetic and pharmacodynamic properties, efficacies and safety profiles. This diversity allows for tailored, personalized approaches to treatment in CKD patients. This review aims to provide a comprehensive overview of vitamin D, including its natural sources and metabolism, and examines the main available pharmacological vitamin D products. Particular emphasis is placed on their application in CKD management, highlighting how these compounds can be strategically used to address both vitamin D deficiency and secondary hyperparathyroidism, while also acknowledging the ongoing debate about their impact on bone health and other clinical outcomes.

The effect of active vitamin D supplementation on body weight and composition: A meta-analysis of individual participant data

BACKGROUND & AIMS

Obesity is associated with vitamin D (VitD) deficiency. However, previous studies showed mixed effects of VitD (25-hydroxyVitD/calcidiol) supplementation on body weight. The biological actions of VitD require the hydroxylation of inactive VitD into active VitD (1.25-dihydroxyVitD/calcitriol). This step is highly regulated; therefore, supplementing with inactive VitD might not be sufficient to overcome the potential adverse health effects of VitD deficiency. The objective of this study was to conduct a systematic review and individual participant data (IPD) meta-analysis of data acquired from randomised placebo-controlled calcitriol trials (RCTs) to determine the effects of calcitriol on body weight and weight-related parameters.

METHODS

Studies were identified from MEDLINE, EMBASE, and CENTRAL databases up to January 27, 2024, and excluded those involving dialysis or cancer patients. We obtained IPD from eligible trials and assessed bias using the Cochrane Collaboration risk-of-bias tool and methodological quality using the Heyland Methodological Quality Score. The study was prospectively registered with PROSPERO (CRD42017076202).

RESULTS

Although none of the studies reported information regarding our primary objective, we obtained IPD for 411 patients, with 206 randomised to receive calcitriol and 205 to placebo. This dataset enabled us to conduct an IPD meta-analysis with 17,084 person-months of follow-up (median: 11 months). Meta-analysis showed that calcitriol does not alter body weight, BMI, waist circumference, fat mass or lean body mass compared to placebo. Adjusting for age and sex did not alter the outcomes.

CONCLUSIONS

In conclusion, this systematic review and IPD meta-analysis indicate that calcitriol does not affect body weight in normal-weight postmenopausal women and lean patients with type 1 diabetes nor in people suffering from obesity, type 2 diabetes and chronic kidney disease. Whether calcitriol lowers body weight in VitD-sufficient people with obesity remains to be elucidated.

Non-Classical Effects of FGF23: Molecular and Clinical Features

This article reviews the role of fibroblast growth factor 23 (FGF23) protein in phosphate metabolism, highlighting its regulation of vitamin D, parathyroid hormone, and bone metabolism. Although it was traditionally thought that phosphate-calcium homeostasis was controlled exclusively by parathyroid hormone (PTH) and calcitriol, pathophysiological studies revealed the influence of FGF23. This protein, expressed mainly in bone, inhibits the renal reabsorption of phosphate and calcitriol formation, mediated by the α-klotho co-receptor. In addition to its role in phosphate metabolism, FGF23 exhibits pleiotropic effects in non-renal systems such as the cardiovascular, immune, and metabolic systems, including the regulation of gene expression and cardiac fibrosis. Although it has been proposed as a biomarker and therapeutic target, the inhibition of FGF23 poses challenges due to its potential side effects. However, the approval of drugs such as burosumab represents a milestone in the treatment of FGF23-related diseases.

Type 2 diabetes mellitus plays a protective role against osteoporosis --mendelian randomization analysis

BACKGROUND

Type 2 diabetes mellitus (DM2) and osteoporosis (OP) are currently the two most significant causes of mortality and morbidity in older adults, according to clinical evidence. The intrinsic link between them is yet unknown, despite reports of their coexistence. By utilizing the two-sample Mendelian randomization (MR) approach, we sought to evaluate the causal impact of DM2 on OP.

METHODS

The aggregate data of the whole gene-wide association study (GWAS) were analyzed. A two-sample MR analysis was performed using single-nucleotide polymorphisms (SNPs), which are strongly associated with DM2, as instrumental variables (IVs) to evaluate the causal analysis of DM2 on OP risk with OR values, using inverse variance weighting, MR-egger regression, and weighted median methods, respectively.

RESULT

A total of 38 single nucleotide polymorphisms were included as tool variables. According to the results of inverse variance-weighted (IVW), we found that there was a causal relationship between DM2 and OP, in which DM2 had a protective effect on OP. For each additional case of DM2, there is a 0.15% decrease in the odds of developing OP (OR = 0.9985;95%confidence interval:0.9974,0.9995; P value = 0.0056). There was no evidence that the observed causal effect between DM2 and the risk of OP was affected by genetic pleiotropy (P = 0.299). Using Cochran Q statistics and MR-Egger regression in the IVW approach, the heterogeneity was calculated; P > 0.05 shows that there is a significant amount of heterogeneity.

CONCLUSION

A causal link between DM2 and OP was established by MR analysis, which also revealed that DM2 decreased the occurrence of OP.

Biochemical Markers of Bone Fragility in Patients with Diabetes. A Narrative Review by the IOF and the ECTS

CONTEXT

The risk of fragility fractures is increased in both type 1 and type 2 diabetes. Numerous biochemical markers reflecting bone and/or glucose metabolism have been evaluated in this context. This review summarizes current data on biochemical markers in relation to bone fragility and fracture risk in diabetes.

METHODS

Literature review by a group of experts from the International Osteoporosis Foundation (IOF) and European Calcified Tissue Society (ECTS) focusing on biochemical markers, diabetes, diabetes treatments and bone in adults.

RESULTS

Although bone resorption and bone formation markers are low and poorly predictive of fracture risk in diabetes, osteoporosis drugs seem to change bone turnover markers in diabetics similarly to non-diabetics, with similar reductions in fracture risk. Several other biochemical markers related to bone and glucose metabolism have been correlated with BMD and/or fracture risk in diabetes, including osteocyte-related markers such as sclerostin, HbA1c and advanced glycation end products (AGEs), inflammatory markers and adipokines, as well as IGF-1 and calciotropic hormones.

CONCLUSION

Several biochemical markers and hormonal levels related to bone and/or glucose metabolism have been associated with skeletal parameters in diabetes. Currently, only HbA1c levels seem to provide a reliable estimate of fracture risk, while bone turnover markers could be used to monitor the effects of anti-osteoporosis therapy.