Modulation of cardiometabolic risk and CardioRenal syndrome by oral vitamin D3 supplementation in Black and White Southern Sahara residents with chronic kidney disease Stage 3: focus on racial and ethnic disparities.

OBJECTIVES: Several studies have shown that cholecalciferol supplementation (25OHD-S) in chronic kidney disease (CKD) improves kidney injury by reducing fibrosis-related vascular calcification and declining apoptosis-linked nephron damage. METHODS: The oral 25OHD-S was evaluated in 60,000 IU/month/36 weeks versus in 2000 IU/d/24 weeks in CKD Stage 3 with serum 25OHD level < 20 ng/mL. The study was undertaken on 156 black subjects and 150 white subjects Southern Sahara (SS). All biomarkers of cardiometabolic (CMet) and cardiorenal (CRenal) syndrome, Renin-angiotensin-aldosterone system (RAAS) profile, secondary hyperparathyroidism (SHPT), N-terminal pro B-type natriuretic peptide (NT-proBNP), Troponin T (cTnT) and atherogenicity risk were assessed by biochemical methods. Estimate glomerular filtration rate (eGFR) by chronic CKD-EPI equation formula. Total serum vitamin D by liquid chromatography-tandem mass spectrometry (MS). RESULTS: Vitamin D deficiency alters in the same manner CMet, CRenal, and others biomarkers in both groups SS; however, these disorders are more acute in blacks compared to whites SS. Oral 25OHD-S a highlighted improvement of eGFR drop, SHPT decrease, decline proteinuria, and cardiac failure risk (NT-proBNP and cTnT) attenuation. Concomitantly, 25OHD-S normalizes Renin, Aldosterone, and Angiotensin System (RAAS) activity. Nevertheless, homocysteine and Lp (a) do not modulate by 25OHD-S. CONCLUSIONS: The oral vitamin D3 supplementation, according the dose, and the treatment duration does not like in black-skinned people versus to white-skinned inhabitants, while the 02 groups are native to the same Saharan environment. It emerge that a high intermittent dose through an extensive supplementation (60,000 IU/36 weeks) was more effective in black subjects. At opposite, a lower dose during a short period supplementation is sufficient (2000 IU/24 weeks) in white subjects.

Oral Cholecalciferol Supplementation in Sahara Black People with Chronic Kidney Disease Modulates Cytokine Storm, Oxidative Stress Damage and Athero-Thromboembolic Risk.

The 25-hydroxyvitamin D3 (25OHD3) deficiency in chronic kidney disease (CKD) is associated with immune system dysfunction (pro-inflammatory cytokines storm) through macrophages renal infiltration, oxidative stress (OxS) damage and athero-thromboembolic risk. Conversely, cholecalciferol supplementation (25OHD-S) prevents kidney fibrosis by inhibition of vascular calcification and nephrotic apoptosis (nephrons reduction). The objective of this study was to investigate the pleiotropic effects of 25OHD-S on immunomodulation, antioxidant status and in protecting against thromboembolic events in deficiency CKD Black and White individuals living in the Southern Sahara (SS). The oral 25OHD-S was evaluated in 60,000 IU/month/36 weeks versus in 2000 IU/day/24 weeks in Black (n = 156) and White (n = 150). Total serum vitamin D was determined by liquid chromatography-tandem mass spectrometry. All biomarkers of pro-inflammatory cytokines (PIC) were assessed by ELISA tests. OxS markers were assessed by Randox kits. Homocysteine and lipoproteine (a) were evaluated by biochemical methods as biomarkers of atherothromboembolic risk. All statistical analyses were performed with Student's t-test and one-way ANOVA. The Pearson test was used to calculate the correlation coefficient. The means will be significantly different at a level of p value < 0.05. Multiple logistic regressions were performed using Epi-info and Statview software. Vitamin D deficiency alters the PIC profile, OxS damage and atherothrombogenic biomarkers in both SS groups in the same manner; however, these disorders are more acute in Black compared to White SS individuals. The results showed that the serum 25OHD3 concentrations became normal (>75 nmol/L or >30 ng/mL) in the two groups. We have shown that the dose and duration of 25OHD-S treatment are not similar in Black SS residents compared to White SS subjects, whilst the same inhabit the south Sahara environment. It appears that a high dose intermittent over a long period (D60: 36 weeks) was more efficient in Black people; while a lower dose for a short time is sufficient (D2: 24 weeks) in their White counterparts. The oral 25OHD-S attenuates PIC overproduction and OxS damage, but does not reduce athero-thromboembolic risk, particularly in Black SS residents.

[Effects of oral vitamin D3 supplementation in stage 3 chronic kidney disease subjects: insulin resistance syndrome and hormonal disturb interactions]. / Effets d'une supplémentation orale en vitamine D3 chez des sujets atteints de maladie rénale chronique au stade 3 : interactions avec le syndrome d'insulinorésistance et les perturbations hormonales.

The 1-25-hydroxyvitamine D (1-25OHD) or calcitriol deficiency in chronic kidney disease (CKD) patients was associated with increases vascular calcification risk, nephrons reduction, bone deficit and cardiovascular mortality by atherosclerosis. The objective of this study was to investigate the pleiotropic effects of 200.000 IU (D200 group) every 3 months versus 30.000 IU (D30 group) every month dose vitamin D supplementation in stage 3 CKD patients. A cohort of 132 adult subjects was randomized into 2 groups according to dose vitamin D supplementation in deficient subjects (25OHD <50 nmol/L or <20 ng/mL). Serum 25OHD levels were assessed before and after 6 and 12 months of vitamin D supplementation. Patients were phenotyped for IRS according to NCEP/ATPIII. Glomerular filtration rate (GFR) by the MDRD formula. Insulin resistance was evaluated by the Homa-IR model. IRS clusters by Cobas Integra 400®. PTH, Cortisol and IGF-1 were determined by radioimmunologic methods. The 25OHD profile was analyzed by LC-MS/MS. Results showed that vitamin D supplementation increased serum 25OHD concentrations (>75 nmol/L or >30 ng/mL) in both groups; however, the supplementation benefits are more significant in D30 group than in D200 group. We noted a highlighted improvement of kidney function, an inhibition of GFR collaps, a safe reduction of proteinuria, a significant PTH and C-reactive protein (inflammation) levels attenuation, concomitantly with cortisolemia normalization and decreased IGF-1 depletion. Nevertheless, homocysteine and Lp(a) concentrations remain increased, not modulated by vitamin D treatment. This study shows that continuous low doses (30.000 IU every month) are recommended for intermittent high doses (200.000 IU every 3 months) vitamin D supplementation. Our study suggests that the serum 25OHD profile can be considered a reliable biomarker in the bioclinic CKD status to stage stabilization and inhibit its evolution.