Effects of vitamin D combined with pioglitazone hydrochloride on bone mineral density and bone metabolism in Type 2 diabetic nephropathy

Changes in Bone Turnover, Inflammatory, Oxidative Stress, and Metabolic Markers in Women Consuming Iron plus Vitamin D Supplements: a Randomized Clinical Trial

We aimed to investigate whether combination of vitamin D and iron supplementation, comparing vitamin D alone, could modify bone turnover, inflammatory, oxidative stress, and metabolic markers. Eighty-seven women with hemoglobin (Hb) ≤ 12.7 g/dL and 25OHD ≤ 29 ng/mL vitamin D deficiency/insufficiency aged 18-45 years were randomly assigned into two groups: (1) receiving either 1000 IU/day vitamin D3 plus 27 mg/day iron (D-Fe); (2) vitamin D3 plus placebo supplements (D-P), for 12 weeks. In D-Fe group, significant decrease in red blood cells (RBC) (P = 0.001) and hematocrit (Hct) (P = 0.004) and increases in mean corpuscular hemoglobin concentration (MCHC) (P = 0.001), 25OHD (P < 0.001), osteocalcin (P < 0.001), high-density cholesterol (HDL) (P = 0.041), and fasting blood sugar (FBS) (P < 0.001) were observed. D-P group showed significant decrease in RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), mean corpuscular volume (MCV) (P = 0.004), mean corpuscular hemoglobin (MCH) (P < 0.001), MCHC (P = 0.005), serum ferritin (P < 0.001), and low-density cholesterol (LDL) (P = 0.016) and increases of 25OHD (P < 0.001), osteocalcin (P < 0.001), C-terminal telopeptide (CTX) (P = 0.025), triglyceride (TG) (P = 0.004), FBS (P < 0.001), and interleukin-6 (IL-6) (P = 0.001) at week 12. After the intervention, the D-P group had between-group increases in mean change in the osteocalcin (P = 0.007) and IL-6 (P = 0.033), and decreases in the RBC (P < 0.001), Hb (P < 0.001), Hct (P < 0.001), and MCV (P = 0.001), compared with the D-Fe group. There were significant between-group changes in MCH (P < 0.001), MCHC (P < 0.001), ferritin (P < 0.001), and serum iron (P = 0.018). Iron-vitamin D co-supplementation does not yield added benefits for improvement of bone turnover, inflammatory, oxidative stress, and metabolic markers, whereas, vitamin D alone may have some detrimental effects on inflammatory and metabolic markers. IRCT registration number: IRCT201409082365N9.

The Emerging Role of Vitamin D and Vitamin D Receptor in Diabetic Nephropathy

Diabetic nephropathy (DN), one of the most common and severe microvascular complications of diabetes mellitus (DM), is an important risk factor for DM patient's death. Nowadays, DN has become the leading cause of end-stage renal disease (ESRD) in most countries without effective therapeutic methods. Recently, the renoprotective effects mediated by vitamin D (VD) and vitamin D receptor (VDR) have been evidenced. VD, a kind of steroid with the active form 1,25(OH)₂D₃, has been known for the crucial roles in the modulation of serum calcium and phosphorus concentrations. It exerts important functions by binding with its receptor VDR.VDR, a transcription factor located at chromosome 12 containing 9 exons, is one of the nonsteroid nuclear hormone receptor superfamily, which participates in transcriptional regulation of genes in tissue- and cell-specific ways. Increasing evidences have demonstrated that VD/VDR signaling pathway possesses a variety of kidney-protective effects in DN patients, such as antiproteinuria, antifibrosis, anti-inflammatory, and preventing podocyte damage. Although there are many studies on the role of the VD/VDR signaling pathway in DN, the effects and mechanisms still need to be further explained. This review summarized the multiple roles of VD/VDR in podocyte injury, tubule lesions, interstitial fibrosis, and inflammation, as well as the clinical applications about DN to explore much more and effective therapeutic methods for DN.

The analysis of risk factors for diabetic nephropathy progression and the construction of a prognostic database for chronic kidney diseases

Background

Diabetic nephropathy (DN) affects about 40% of diabetes mellitus (DM) patients and is the leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) all over the world, especially in high- and middle-income countries. Most DN has been present for years before it is diagnosed. Currently, the treatment of DN is mainly to prevent or delay disease progression. Although many important molecules have been discovered in hypothesis-driven research over the past two decades, advances in DN management and new drug development have been very limited. Moreover, current animal/cell models could not replicate all the features of human DN, while the development of Epigenetics further demonstrates the complexity of the mechanism of DN progression. To capture the key pathways and molecules that actually affect DN progression from numerous published studies, we collected and analyzed human DN prognostic markers (independent risk factors for DN progression).

Methods

One hundred and fifty-one DN prognostic markers were collected manually by reading 2365 papers published between 01/01/2002 and 12/15/2018. One hundred and fifteen prognostic markers of other four common CKDs were also collected. GO and KEGG enrichment analysis was done using g:Profiler, and a relationship network was built based on the KEGG database. Tissue origin distribution was derived mainly from The Human Protein Atlas (HPA), and a database of these prognostic markers was constructed using PHP Version 5.5.15 and HTML5.

Results

Several pathways were significantly enriched corresponding to different end point events. It is shown that the TNF signaling pathway plays a role through the process of DN progression and adipocytokine signaling pathway is uniquely enriched in ESRD. Molecules, such as TNF, IL6, SOD2, etc. are very important for DN progression, among which, it seems that “AGER” plays a pivotal role in the mechanism. A database, dbPKD, was constructed containing all the collected prognostic markers.

Conclusions

This study developed a database for all prognostic markers of five common CKDs, offering some bioinformatics analyses of DN prognostic markers, and providing useful insights towards understanding the fundamental mechanism of human DN progression and for identifying new therapeutic targets.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2016-y) contains supplementary material, which is available to authorized users.