Lower Blood Vitamin D Levels Are Associated With an Increased Incidence of Contrast-Induced Nephropathy in Patients Undergoing Coronary Angiography

Vitamin D deficiency may increase the risk of acute kidney injury in patients with diabetes and predict a poorer outcome in patients with acute kidney injury

BACKGOUND

People with diabetes are much more likely to develop acute kidney injury (AKI) than people without diabetes. Low 25-hydroxy-vitamin D [25(OH)D] concentrations increased the risk of AKI in specific populations. Few studies have explored the relationship between the 25(OH)D level and AKI in patients with diabetes. We conducted this study to investigate the relationship between the plasma level of 25(OH)D and the risk of AKI in patients with diabetes, and to evaluate whether the 25(OH)D level could be a good prognostic marker for AKI progression.

METHODS

A total of 347 patients with diabetes were retrospectively reviewed. The primary endpoint was the first event of AKI. The secondary endpoint is need-of-dialysis. AKI patients were further followed up for 6 months with the composite endpoint of end-stage renal disease (ESRD) or all-cause death. Kaplan-Meier survival analysis and Cox proportional hazards models were used.

RESULTS

During a median follow-up of 12 weeks (12.3 ± 6.7), 105 incident AKI were identified. The middle and high tertiles of baseline 25(OH)D levels were associated with a significantly decreased risk of AKI and dialysis compared to the low tertile group (HR = 0.25, 95% CI 0.14-0.46; HR = 0.24, 95% CI 0.13-0.44, respectively, for AKI; HR = 0.15; 95% CI 0.05-0.46; HR = 0.12; 95% CI 0.03-0.42, respectively, for dialysis). Sensitivity analysis revealed similar trends after excluding participants without history of CKD. Furthermore, AKI patients with 25(OH)D deficiency were associated with a higher risk for ESRD or all-cause death (HR, 4.24; 95% CI, 1.80 to 9.97, P < 0.001).

CONCLUSION

A low 25 (OH) vitamin D is associated with a higher risk of AKI and dialysis in patients with diabetes. AKI patients with 25(OH)D deficiency were associated with a higher risk for ESRD or all-cause death.

Associations between Serum 25-hydroxyvitamin D, Sun Exposure Time, Dietary Vitamin D Intake, and New-Onset Acute Kidney Injury among 413,169 UK Adults

BACKGROUND

The prospective associations of serum 25(OH)D, sun exposure time, and dietary vitamin D with risk of acute kidney injury (AKI) are unclear.

OBJECTIVES

We aimed to evaluate the relations of serum 25(OH)D, sun exposure time, and dietary vitamin D intake with new-onset AKI and examine whether genetic susceptibility modified such associations.

METHODS

A total of 413,169 participants (mean age was 56.4 y, 47.2% were male) from UK Biobank without prior AKI were included. Sun exposure time was expressed as time spent outdoors. Genetic risk scores were calculated by 263 single nucleotide polymorphisms, which showed significant associations with the estimated glomerular filtration rate. The primary outcome was new-onset AKI. Cox proportional hazards models were used to estimate the HRs and (95% CIs).

RESULTS

During a median follow-up duration of 12 y, 16,938 (4.1%) participates developed new-onset AKI. Compared with those with serum 25(OH)D <25 nmol/L, significantly lower risks of new-onset AKI were found between participants with 25(OH)D 25 to <50 nmol/L (adjusted HR: 0.76; 95% CI: 0.73, 0.80), and ≥50 nmol/L (adjusted HR: 0.69; 95% CI: 0.65, 0.72). Moreover, in summer, participants who spent ≥4 h outdoors per day (tertile 3) had a significantly lower risk of new-onset AKI (adjusted HR: 0.90; 95% CI: 0.86, 0.95) than those who spent <2 h outdoors per day (tertile 1). Similar results were found for time spent outdoors in winter. In addition, those in quintile 5 of dietary vitamin D intake showed a lower risk of new-onset AKI (≥4.2 μg/d, adjusted HR: 0.90; 95% CI: 0.82, 0.98) than those in quintile 1 (<1.0 μg/d). Genetic risks of kidney diseases did not significantly modify all the 3 above associations (all P-interactions >0.05).

CONCLUSIONS

Serum 25(OH)D concentrations, time spent outdoors, and dietary vitamin D intake were all inversely associated with new-onset AKI, independent of genetic risks for kidney diseases.

A Narrative Review of Recent Studies on the Role of Vitamin D in the Prevention of Cardiac and Renal Risk and Additional Considerations for COVID-19 Vulnerability

The role of vitamin D in maintaining a healthy cardiovascular (CV) and the renal system has received increasing attention. Low vitamin D levels are associated with the incidence of hypertension, cardiac remodeling, and chronic congestive heart failure. Low vitamin D levels also influence renal disease progression and albuminuria deterioration. Moreover, recent research indicates that vitamin D deficiency can be a potential risk factor for coronavirus disease-19 (COVID-19) infection and poorer outcomes. Data are inconclusive as to whether supplementation with vitamin D agents reduces CV disease risk or COVID-19 severity. Conversely, in patients with kidney disease, vitamin D supplementation is associated with an improvement in kidney function and albuminuria. This narrative review considers recent data on the effects of vitamin D on the CV and renal system, as well as its possible role regarding COVID-19 complications.

Current Smoking is a Risk Factor for the Irregular Surface and Calcification of Carotid Plaque in Men

Objective

To explore whether current smoking could influence plaque characteristics and determine its correlation to the irregular surface and calcification of carotid plaque.

Methods

Three hundred and seventeen patients with severe carotid atherosclerosis stenosis (SCAS) detected by color duplex flow imaging (CDFI) and confirmed by CT angiography (CTA) were recruited. The results of laboratory parameters were collected by using electronic database of the hospital. Computerized tomography (CT) scanning and high-resolution ultrasonography were performed for assessment of plaque morphology, respectively.

Results

All enrolled smokers and non-smokers had no significant difference among all characteristics not related to smoking. CT scanning could efficiently identify the difference among enrolled smokers and non-smokers not only for the characteristics related to smoking but also the onsets of carotid plaque. Surface morphology was also efficiently detected by ultrasonography. Further ridge trace analysis showed that ultrasonography is efficient for diagnosis of calcified plaque compared with gold standard for plaque diagnosis. Further correlation analysis showed that ultrasonography parameters could offer reliable evidence for plaque scores, which was associated with age index. Ultrasonography parameters could efficiently differentiate plaque morphologies among enrolled smokers and never-smokers.

Conclusion

Current smoking was positively associated with plaque calcification onsets, and smoking cessation could efficiently attenuate such injury. High-frequency ultrasound can clearly distinguish the details of calcification with promising clinical significance for current smoking patients.

Vitamin D and Acute Kidney Injury: A Two-Way Causality Relation and a Predictive, Prognostic, and Therapeutic Role of Vitamin D

Background: Acute kidney injury (AKI) constitutes a multi-factorially caused condition, which significantly affects kidney function and can lead to elevated risk of morbidity and mortality. Given the rising scientific evidence regarding vitamin D's (VitD's) multisystemic role, the connection between AKI and VitD is currently being studied, and the complex relation between them has started to be unraveled.

Methods: A systematic review had been conducted to identify the pathogenetic relation of VitD and AKI and the potential role of VitD as a biomarker and therapeutic–renoprotective factor.

Results: From 792 articles, 74 articles were identified that fulfilled the inclusion criteria. Based on these articles, it has been found that not only can VitD disorders (VitD deficiency or toxicity) cause AKI but, also, AKI can lead to great disruption in the metabolism of VitD. Moreover, it has been found that VitD serves as a novel biomarker for prediction of the risk of developing AKI and for the prognosis of AKI's severity. Finally, animal models showed that VitD can both ameliorate AKI and prevent its onset, suggesting its renoprotective effect.

Conclusion: There is a complex two-way pathogenetic relation between VitD disorders and AKI, while, concomitantly, VitD serves as a potential novel predictive–prognostic biomarker and a treatment agent in AKI therapy.

Risk factors of contrast-induced nephropathy in patients with STEMI and pump failure undergoing percutaneous coronary intervention

Risk factors associated with the development of contrast-induced nephropathy (CIN) remain poorly defined in patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). The present study was designed to assess the association between the Killip grade and the development of CIN in patients with STEMI and pump failure undergoing PCI. Data were retrospectively collected from the records of patients with STEMI and pump failure from the Chinese Society of Cardiology and American Heart Association database. A total of 7,471 patients were analyzed, including 5,521 patients with Killip grade II, 878 with Killip III and 1,072 with Killip IV pump failure. Patients were classified into two groups: Those undergoing primary PCI (PPCI; n=5,063) and those undergoing elective PCI (EPCI; n=2,408). Patients in the PPCI group had higher cardiac arrest rates, lower blood pressure and higher cholesterol levels as compared to the EPCI group. There was a statistically significant difference in the rates of CIN with Killip II pump failure in the PPCI group as compared to the EPCI group, but not in those with Killip III and VI pump failure. Logistic regression analysis indicated that the Killip classification is a risk predictor for post-PCI CIN. The present results indicated a positive association between the Killip grade and post-PCI CIN in patients with STEMI and pump failure. In addition, patients with STEMI and Killip grade II pump failure were at a higher risk of PCI after PPCI as compared to EPCI. Further prospective studies are required to confirm the present results.

Assessment of 25-Hydroxyvitamin D Levels in Patients with Resistant Hypertension

OBJECTIVE

To investigate the possible correlation between serum 25-hydroxyvitamin D levels and resistant hypertension (RH).

SUBJECTS AND METHODS

Patients who had undergone ambulatory blood pressure measurements (ABPM) during outpatient controls were enrolled. Fifty subjects with RH, 50 with controlled hypertension (CHT) and 50 normotensive subjects (NT) were included in the study. RH was defined as 'suboptimal blood pressure control despite using 3 antihypertensive agents including a diuretic or need for 4 or more drugs to control blood pressure'. The 25-hydroxyvitamin D and parathormone levels were compared between the groups. Pearson's correlation coefficient test was applied to assess the correlation between 25-hydroxyvitamin D levels and office blood pressure (BP) and ABPM. Logistic regression analysis was used to determine the independent correlates of RH.

RESULTS

The 25-hydroxyvitamin D level was significantly lower in the RH group (17.02 ± 5.4 ng/ml) compared to the CHT (24.9 ± 4.8 ng/ml) and NT groups (28.0 ± 5.7 ng/ml, p < 0.001). In univariate correlation analysis, 25-hydroxyvitamin D levels had a significant negative correlation with office systolic BP (r = -0.329, p < 0.001), office diastolic BP (r = -0.395, p < 0.001), systolic ambulatory BP (r = -0.844, p = 0.004), and diastolic ambulatory BP (r = -0.567, p = 0.005). ROC analysis revealed that 25-hydroxyvitamin D levels <21.50 ng/ml predicted the presence of RH with a sensitivity of 78% and a specificity of 79% (AUC = 0.89, 95% CI 0.83-0.94). In the multivariate logistic regression analysis, 25-hydroxyvitamin D level was independently correlated with the presence of RH (β 0.660, 95% CI 0.572-0.760, p < 0.001).

CONCLUSION

There was an independent correlation between lower 25-hydroxyvitamin D levels and presence of RH.

Vitamin D deficiency is a potential risk factor for contrast-induced nephropathy

Vitamin D deficiency (VDD) is widespread in the general population. Iodinated (IC) or gadolinium-based contrast media (Gd) may decrease renal function in high-risk patients. This study tested the hypothesis that VDD is a predisposing factor for IC- or Gd-induced nephrotoxicity. To this end, male Wistar rats were fed standard (SD) or vitamin D-free diet for 30 days. IC (diatrizoate), Gd (gadoterate meglumine), or 0.9% saline was then administered intravenously and six groups were obtained as the following: SD plus 0.9% saline (Sham-SD), SD plus IC (SD+IC), SD plus Gd (SD+Gd), vitamin D-free diet for 30 days plus 0.9% saline (Sham-VDD30), vitamin D-free diet for 30 days plus IC (VDD30+IC), and vitamin D-free diet for 30 days plus Gd (VDD30+Gd). Renal hemodynamics, redox status, histological, and immunoblot analysis were evaluated 48 h after contrast media (CM) or vehicle infusion. VDD rats showed lower levels of total serum 25-hydroxyvitamin D [25(OH)D], similar plasma calcium and phosphorus concentration, and higher renal renin and angiotensinogen protein expression compared with rats fed SD. IC or Gd infusion did not affect inulin clearance-based estimated glomerular filtration rate (GFR) in rats fed SD but significantly decreased GFR in rats fed vitamin D-free diet. Both CM increased renal angiotensinogen, and the interaction between VDD and CM triggered lower renal endothelial nitric oxide synthase abundance and higher renal thiobarbituric acid reactive substances-to-glutathione ratio (an index of oxidative stress) on VDD30+IC and VDD30+Gd groups. Conversely, worsening of renal function was not accompanied by abnormalities on kidney structure. Additionally, rats on a VDD for 60 days displayed a greater fall in GFR after CM administration. Collectively, our findings suggest that VDD is a potential risk factor for IC- or Gd-induced nephrotoxicity most likely due to imbalance in intrarenal vasoactive substances and oxidative stress.

Brain natriuretic peptide for prevention of contrast-induced nephropathy after percutaneous coronary intervention or coronary angiography

BACKGROUND

Many methods reportedly prevent contrast-induced nephropathy (CIN), but the effect of brain natriuretic peptide (BNP) on CIN is unknown. In this study we investigated recombinant BNP use before coronary angiography (CA) or nonemergent percutaneous coronary intervention (PCI) in patients with unstable angina.

METHODS

One thousand patients with unstable angina were prospectively evaluated. The patients were randomly assigned to: group A, isotonic normal saline (NaCl 0.9%, 1 mL/kg/h) for 24 hours before CA or PCI; and group B, human recombinant BNP (rhBNP; 0.005 μg/kg/min). Serum creatinine (Scr) levels and estimated glomerular filtration rate were measured before and 24, 48, and 72 hours, and 7 days after the procedure. The primary outcome was CIN incidence defined according to a relative (≥ 25%) or absolute (≥ 0.5 mg/dL and 44 μmol/L, respectively) increase in Scr from baseline within 48 hours. The secondary end points were the changes in the Scr and estimated glomerular filtration rate, before and after the procedure.

RESULTS

Contrast volume, a history of diabetes mellitus, and BNP administration independently predicted CIN. The incidence of CIN was significantly greater in group A than in group B (14.8% vs 5.6%; P < 0.01). Renal function was less compromised in patients who received rhBNP. The Scr of all patients with CIN remained increased for 24 hours, but it was lower and recovered faster in patients who received rhBNP.

CONCLUSIONS

rhBNP administration before CA or PCI protects renal function and can significantly decrease CIN incidence.