Digitalni repozitorij raziskovalnih organizacij Slovenije

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po

Možnosti:
  Ponastavi


Iskalni niz: "avtor" (Darko Siuka) .

1 - 10 / 10
Na začetekNa prejšnjo stran1Na naslednjo stranNa konec
1.
The effect of vitamin D levels on the course of COVID-19 in hospitalized patients – a 1-year prospective cohort study [version 1; peer review: awaiting peer review]
Darko Siuka, Rajko Saletinger, Jure Uršič, Kristina J. Hartung, Rado Janša, David Štubljar, Joško Osredkar, 2023, izvirni znanstveni članek

Povzetek: Background: The aim of the current study was to assess the patients with COVID-19 and the impact of vitamin D supplementation on the course of COVID-19. Methods: This prospective cohort study included patients hospitalized due to COVID-19 between December 2020 and December 2021. Patients' demographic, clinical, and laboratory parameters were analysed. Results: 301 participants were enrolled in the study. 46 (15,3%) had moderate, and 162 (53,8%) had severe COVID-19. 14 (4,7%) patients died, and 30 (10,0%) were admitted to the ICU due to disease worsening. The majority needed oxygen therapy (n=224; 74,4%). Average vitamin 25(OH)D3 levels were below optimal at the admittance, and vitamin D deficiency was detected in 205 individuals. More male patients were suffering from vitamin D deficiency. Patients with the more severe disease showed lower levels of vitamin 25(OH)D3 in their blood. The most severe group of patients had more symptoms that lasted significantly longer with progressing disease severity. This group of patients also suffered from more deaths, ICU admissions, and treatments with dexamethasone, remdesivir, and oxygen. Conclusion: Patients with the severe course of COVID-19 were shown to have increased inflammatory parameters, increased mortality, and higher incidence of vitamin D deficiency. The results suggest that the vitamin D deficiency might represent a significant risk factor for a severe course of COVID-19.
Ključne besede: vitamin D, COVID-19, severity, supplementation
Objavljeno v DiRROS: 31.08.2026; Ogledov: 114; Prenosov: 52
.pdf Celotno besedilo (703,67 KB)
Gradivo ima več datotek! Več...

2.
Ten-year trends in serum 25-hydroxyvitamin D in Slovenia (2014–2023) : laboratory-based data from tested individuals and COVID-19-period changes
Joško Osredkar, Darko Siuka, Aleš Jerin, Borut Štabuc, Uroš Godnov, 2026, izvirni znanstveni članek

Povzetek: Background: Vitamin D status is influenced by season, age, and public health messaging. The COVID-19 pandemic was accompanied by heightened interest in vitamin D, but long-term national data from Central/Eastern Europe remain limited. We aimed to characterize 10-year trends, seasonal variation, and demographic determinants of serum 25-hydroxyvitamin D [25(OH)D] in Slovenia, with particular focus on changes during the COVID-19 period. Methods: We performed a retrospective cross-sectional analysis of all serum 25(OH)D measurements performed at the Slovenian national reference laboratory between January 2014 and December 2023. The core analytic cohort included 106,875 patients with valid 25(OH)D results, aged 0–100 years. Vitamin D status was classified as deficient (<30 nmol/L), insufficient (30–50 nmol/L), adequate (50–75 nmol/L), and optimal (>75 nmol/L). Temporal trends, seasonal patterns, and age- and sex-specific differences were assessed using non-parametric tests and Kendall’s τ. Results: Mean 25(OH)D concentration over the study period was 61.9 ± 34.2 nmol/L; 16.0% of patients were deficient and 22.8% insufficient. Annual mean 25(OH)D increased from 57.0 nmol/L in 2014 to 67.2 nmol/L in 2023, with a significant upward temporal trend and a 14.6% higher mean level during 2020–2023 compared with 2014–2019. Seasonal variation was pronounced (≈20% higher summer–autumn vs. winter–spring), and vitamin D status declined progressively with age, with the highest deficiency prevalence in patients ≥ 70 years. Females had slightly higher 25(OH)D than males, although absolute differences were small. Conclusions: This laboratory-based analysis of tested patients showed higher 25(OH)D concentrations during and after the COVID-19 period, superimposed on persistent seasonal and age-related gradients. These observations identify older adults and winter testing periods as important contexts for vitamin D optimization, but they should be interpreted as descriptive trends among tested individuals rather than as evidence of causal pandemic effects or population-wide prevalence changes.
Ključne besede: 25-hydroxyvitamin D, seasonal variation, deficiency, age factors, COVID-19 pandemic
Objavljeno v DiRROS: 24.04.2026; Ogledov: 344; Prenosov: 270
.pdf Celotno besedilo (1,54 MB)
Gradivo ima več datotek! Več...

3.
Disrupted vitamin D metabolism in hepatocellular carcinoma : free and bioavailable 25(OH)D as novel biomarkers of hepatic reserve and clinical risk
Joško Osredkar, Matej Rakuša, Aleš Jerin, Borut Štabuc, Martin Zaplotnik, Saša Štupar, Darko Siuka, 2026, izvirni znanstveni članek

Povzetek: Background: Although total 25-hydroxyvitamin D (25(OH)D) measurements may not accurately reflect functional vitamin D status, vitamin D deficiency is common in hepatocellular carcinoma (HCC). The contribution of altered vitamin D-binding protein (VDBP) and albumin to impaired bioavailability is poorly characterized in liver cancer. Methods: We measured total, free, and bioavailable 25(OH)D, VDBP, and albumin in 46 HCC patients and 87 healthy controls during winter and summer. Correlations with Child–Pugh score, Barcelona Clinic Liver Cancer (BCLC) stage, and disease aetiology were evaluated. Results: HCC patients exhibited significantly lower VDBP (177.3 ± 237.0 vs. 239.9 ± 141.9 mg/L, p < 0.001) and albumin (35.9 ± 5.4 vs. 48.0 ± 3.9 g/L, p < 0.001) compared to winter controls. Total 25(OH)D was lower in HCC (39.3 ± 22.1 nmol/L) versus summer controls (75.0 ± 22.8 nmol/L, p < 0.001) but comparable to winter controls (p = 0.061). HCC patients lacked seasonal variation in vitamin D fractions, unlike the controls. VDBP negatively correlated with free (ρ = −0.606, p < 0.001) and bioavailable 25(OH)D (ρ = −0.541, p < 0.001). Child–Pugh score correlated positively with BCLC stage (ρ = 0.378, p = 0.012) and inversely with albumin (ρ = −0.565, p < 0.001). Conclusions: Free and bioavailable vitamin D are profoundly compromised in HCC, reflecting impaired hepatic synthetic function and systemic inflammation. These fractions may serve as novel metabolic biomarkers superior to total 25(OH)D for assessing vitamin D deficiency and guiding individualized supplementation strategies in patients with liver cancer.
Ključne besede: hepatocellular carcinoma, vitamin D metabolism, 25-hydroxyvitamin D, free vitamin D, bioavailable vitamin D, vitamin D-binding protein, albumin, Child-Pugh score, BCLC staging, biomarkers
Objavljeno v DiRROS: 08.04.2026; Ogledov: 329; Prenosov: 205
.pdf Celotno besedilo (530,80 KB)
Gradivo ima več datotek! Več...

4.
Integrative vitamin D-inflammatory-coagulation biomarker index predicts COVID-19 severity : development and validation of the vitamin D inflammatory burden score (VDIBS)
Joško Osredkar, Uroš Godnov, Darko Siuka, 2026, izvirni znanstveni članek

Povzetek: Vitamin D deficiency is common in hospitalized COVID-19 patients and is associated with increased severity. However, single-biomarker approaches provide insufficient prognostic precision. We developed an integrative inflammatory-metabolic risk index combining vitamin D status, systemic inflammation, and coagulation activation. This is a prospective cohort study of 512 hospitalized COVID-19 patients (September 2022–December 2023) with serum 25(OH)D3 measurement at admission. The primary analysis (N = 301) included patients with complete data for VDIBS-Core components (CRP, ferritin, D-dimer, LDH). The Vitamin D Inflammatory Burden Score-Core (VDIBS-Core; range 0–7) integrated the following: (1) vitamin D tier (deficient < 30 nmol/L: 3 points; insufficient 30–50: 2; non-optimal 50–75: 1; sufficient > 75: 0), (2) inflammation score (CRP ≥ 100, ferritin ≥ 1000 each +1 point; 0–2 total), and (3) coagulation score (D-dimer ≥ 1000, LDH ≥ 3–6 or ≥ 6 each +0–2 points; 0–2 total). The IL-6 measurement (N = 48, 9.4%) was explored separately as VDIBS-Plus in the secondary analysis. The outcomes were severe COVID-19 (defined as the worst severity classification during hospitalization per WHO criteria), ICU admission, and mortality. The mean vitamin D was 63.4 ± 33.2 nmol/L (68.1% deficient). Among N = 301 with complete VDIBS-Core data, severe disease occurred in 221 (73.4%), ICU admission in 15 (5.0%), and mortality in 8 (2.7%). VDIBS-Core risk stratification showed the following: low-risk (VDIBS 0–2, n = 178) 8.4% severe; moderate-risk (VDIBS 3–5, n = 245) 45.7% severe; and high-risk (VDIBS 6–7, n = 89) 78.6% severe; χ2 = 142.3, p < 0.001. VDIBS-Core predicted severe disease with AUC 0.78 (95% CI 0.74–0.82), with excellent calibration (Hosmer–Lemeshow p = 0.40). When compared to complex multivariate models incorporating all seven individual biomarkers, VDIBS-Core demonstrated equivalent discrimination (AUC 0.82, Δ = 0.04, p = 0.08, not statistically significant) with superior clinical simplicity. Bootstrap internal validation confirmed modest optimism (optimism-corrected AUC 0.76). An incremental value analysis demonstrated that the vitamin D component contributes a significant additional predictive value compared to inflammation/coagulation biomarkers alone (LR test p = 0.004). VDIBS-Core provides bedside-implementable risk stratification using three simple components measurable in <5 min, integrating vitamin D-dependent immune regulation with systemic inflammation and coagulation activation. This composite approach offers a practical tool for treatment intensity escalation and monitoring frequency assignment in hospitalized COVID-19 patients. External validation in geographically diverse cohorts is required before widespread clinical implementation.
Ključne besede: vitamin D deficiency, COVID-19 severity, biomarker integration, risk stratification, immunometabolism
Objavljeno v DiRROS: 08.04.2026; Ogledov: 320; Prenosov: 264
.pdf Celotno besedilo (2,93 MB)
Gradivo ima več datotek! Več...

5.
Hemosuccus pancreaticus post-EUS-FNA in multicystic pancreatic tail formation : a case report
Goran Bokan, Eva Mihajlović Mislej, Borut Štabuc, Darko Siuka, 2025, drugi znanstveni članki

Ključne besede: EUS-FNA, gastrointestinal bleeding, hemosuccus pancreaticus
Objavljeno v DiRROS: 26.02.2026; Ogledov: 521; Prenosov: 412
.pdf Celotno besedilo (454,30 KB)
Gradivo ima več datotek! Več...

6.
Vloga citopatologije pri diagnostiki raka trebušne slinavke
Margareta Žlajpah, Damjana Cimerman, Ulrika Klopčič, Darko Siuka, Andrej Gruden, Jan Drnovšek, Margareta Strojan Fležar, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Ključne besede: rak rebušne slinavke, citopatologija, onkologija
Objavljeno v DiRROS: 25.02.2026; Ogledov: 460; Prenosov: 152
.pdf Celotno besedilo (84,57 KB)

7.
8.
Free and bioavailable vitamin D are correlated with disease severity in acute pancreatitis : a single-center, prospective study
Darko Siuka, Matej Rakuša, Aleš Vodenik, Lana Vodnik Klun, Borut Štabuc, David Štubljar, David Drobne, Helena Matelič, Joško Osredkar, 2025, izvirni znanstveni članek

Povzetek: Acute pancreatitis (AP) is primarily caused by inflammation and immunological responses, both of which are regulated by vitamin D. The purpose of this study was to examine the correlation between the severity of AP and vitamin D levels, including its total, free, and bioavailable forms. Eighty individuals with AP were enrolled in this study. Serum levels of free 25(OH)D3, bioavailable 25(OH)D3, and total 25-hydroxyvitamin D 25(OH)D3 were assessed. The severity of the disease course was assessed by scoring systems (Revised Atlanta classification, Ranson score, CTSI). Vitamin D deficiency was common in AP patients, with 31.3% being categorized as deficient (<50 nmol/L) and 27.5% having a severe deficiency (<30 nmol/L). Compared to patients with adequate vitamin D status, those with lower vitamin D levels had a significantly higher risk of developing moderate-to-severe AP (44.7% vs. 14.3%, p = 0.029). Patients with severe vitamin D insufficiency were the only ones who experienced severe AP. Clinical outcomes showed similar correlations: patients with significant vitamin D deficiency had longer hospital stays (mean of 12.1 ± 5.3 days vs. 7.8 ± 3.4 days, p = 0.018) and higher rates of ICU admission (31.8% vs. 8.0%, p = 0.007). Low levels of total, free, and bioavailable vitamin D were significantly associated with the severity of AP and ICU admission. Free, bioavailable, and total vitamin D were correlated with the severity of acute pancreatitis. All severe cases occurred in patients with severe vitamin D deficiency. Given the observational design, these associations require confirmation in interventional or mechanistic studies.
Ključne besede: vitamin D deficiency, acute pancreatitis severity, free and bioavailable vitamin D, inflammation and immune response, clinical outcomes
Objavljeno v DiRROS: 25.11.2025; Ogledov: 721; Prenosov: 489
.pdf Celotno besedilo (342,78 KB)
Gradivo ima več datotek! Več...

9.
Seasonal variation of total and bioavailable 25-hydroxyvitamin D [25(OH)D] in the healthy adult Slovenian population
Joško Osredkar, Vid Vičič, Maša Hribar, Evgen Benedik, Darko Siuka, Aleš Jerin, Urška Čegovnik Primožič, Teja Fabjan, Kristina Kumer, Igor Pravst, 2024, izvirni znanstveni članek

Povzetek: Objective: The aim of our study was to compare the total 25(OH)D fraction, the bioavailable vitamin fraction, and the free vitamin D fraction in spring and fall in a group of healthy individuals. Methods: In our study, we collected blood samples from healthy participants at the end of both summer and winter, and measured serum levels of albumin, DBP, and 25(OH)D. Utilizing these data, we calculated the percentage of free and bioavailable vitamin D. Our cohort comprised 87 participants, with a maleto- female ratio of 14:73, aged 35.95 ± 12.55 years, ranging from 19 to 70 years. We employed the chemiluminescence method to determine the vitamin 25(OH)D levels, the ELISA method was utilized to determine DBP levels, the albumin BCP Assay was performed using the ADVIA biochemical analyzer (Siemens) and an online calculator was used to determine the free and bioavailable 25(OH)D levels. Results: Our findings indicate significantly lower 25(OH)D levels in winter (44.13 ± 17.82 nmol/L) compared to summer (74.97 ± 22.75 nmol/L; p < 0.001). For vitamin D binding protein there was no significant difference from summer (236.2 ± 164.39 mg/L) to winter (239.86 ± 141.9 mg/L; p = 0.77), albumin levels were significantly higher in summer (49.37 ± 4.15 g/L vs. 47.97 ± 3.91 g/L, p = 0.01), but the magnitude of the change may not be large enough to be solely responsible for the stability of vitamin D levels throughout the year. In the winter season a significantly lower calculated bioavailable 25(OH)D vitamin (7.45 ± 5.66 nmol/L against 13.11 ± 8.27 nmol/L; p < 0.001) was observed, and the free fraction also showed a significant decrease (17.3 ± 12.9 pmol/L versus 29.7 ± 19.1 pmol/L; p < 0.0001). We observed a moderately positive correlation between 25(OH)D and bioavailable percentage in winter (r = 0.680; p < 0.001), in contrast with a lower positive association in summer (r = 0.343; p < 0.001). Conclusion: Our data suggest a positive correlation between total and bioavailable 25(OH)D levels. In addition to the statistically significant variation in 25(OH)D between the two observation periods, there was an additional variation in the free vitamin D percentage. The summertime synthesis of vitamin D in the skin could contribute directly to the free fraction of vitamin D. Standardizing the measurement of free 25(OH)D and clinical studies is necessary to establish reference values before these methods can be implemented in clinical practice.
Ključne besede: body mass index, ultraviolet, D3, cholecalciferol, D2, ergocalciferol, total 25(OH)D, 25-hydroxycholecalciferol, calcifediol, calcidiol, 25-hydroxyvitamin, 1, 25-(OH)D, 1, 25-dihydroxyvitamin D, vitamin D binding protein, Odds ratio
Objavljeno v DiRROS: 02.10.2025; Ogledov: 764; Prenosov: 385
.pdf Celotno besedilo (1,40 MB)
Gradivo ima več datotek! Več...

10.
Iskanje izvedeno v 0.21 sek.
Na vrh