Olga Klassen

Dr. Olga Klassen

orcid

Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 August 2025 in Medicina
Verified
Journal Article
Open access
PDF file
LILyazat Ibrayeva
Lyazat Ibrayeva
BIBacheva Irina
Bacheva Irina
AAAssel Alina
Assel Alina
OKOlga Klassen
Olga Klassen
Background and Objectives: Chronic lung diseases act as multi-organ conditions in which systemic inflammation, vascular dysfunction, and fibrosis intersect. The pulmo-renal continuum—functional crosstalk between lungs and kidneys—remains poorly characterized. We compared year-long changes in endothelin-1 (ET-1), galectin-3 (Gal-3), renal indices (eGFR, ACR), and quantitative CT densitometry in COPD and systemic sclerosis-associated ILD (SSc-ILD). Materials and Methods: In this prospective observational study (January 2023–December 2024), 112 patients were consecutively enrolled (COPD, n = 58; SSc-ILD, n = 54). Assessments were performed at baseline and 12 months. ET-1 (ELISA) and Gal-3 (chemiluminescence) were measured in serum; eGFR was calculated by the creatinine-based CKD-EPI (2021) equation; ACR was photometric. High-resolution chest CT provided lung volume and parenchymal density (Hounsfield units) at six predefined axial levels per lung. Non-parametric statistics were applied: Wilcoxon signed-rank (within-group), Mann–Whitney U (between-group), and Spearman rank correlations for associations; results are reported with p-values (and 95% CIs). Results: Baseline eGFR was normal (COPD 90.37; SSc-ILD 92.4 mL/min/1.73 m2). eGFR declined by 6.76% in COPD (p = 0.001) and 3.16% in SSc-ILD (p = 0.029). ET-1 increased in both cohorts but more in COPD (+83.78%, p = 0.0002) than in SSc-ILD (+23.83%, p = 0.0001). Gal-3 rose significantly only in SSc-ILD (+10.2%, p = 0.043). FVC decreased in COPD (−4.01%, p = 0.01) and was unchanged in SSc-ILD. Total lung volume declined in SSc-ILD (−6.08%, p = 0.02) but not in COPD. CT density shifts were small: several slices in COPD and one slice (L6) in SSc-ILD reached statistical but not biological relevance. Conclusions: COPD exhibited larger vascular and renal biomarker shifts (ET-1 up, eGFR down, ACR up), suggesting systemic inflammation and early renal involvement. In SSc-ILD, biomarker and CT changes predominantly reflected pulmonary fibrosis progression with limited renal impact. Integrating biomarkers with quantitative CT may help delineate organ-specific trajectories along the pulmo-renal continuum; longer, larger studies are warranted. Limitations: This was a single-center cohort with a modest sample (58 COPD and 54 SSc-ILD) and a 12-month, two-time-point follow-up, which may not capture long-term trajectories and may limit it generalizability; larger multicenter studies with an extended follow-up are warranted.

28 October 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
LILyazat Ibrayeva
Lyazat Ibrayeva
BIBacheva Irina
Bacheva Irina
AAAssel Alina
Assel Alina
OKOlga Klassen
Olga Klassen
Background/Objectives: Systemic sclerosis-associated interstitial lung disease (SSc-ILD) and chronic obstructive pulmonary disease (COPD) are linked to multi-organ vulnerability involving the lungs, heart, and kidneys. This study aimed to compare the annual changes in pulmonary, cardiac, and renal parameters in patients with SSc-ILD and COPD across three consecutive years, using both individual biomarkers and integrated composite profiles. Methods: This observational longitudinal study included repeated assessments in 2023, 2024, and 2025. Functional, laboratory, and imaging parameters were collected: 6-min walk test (6MWT), SpO2 (pre-/post-exercise), spirometry/CT lung volumes, gas exchange (pO2/pCO2/lactate), echocardiography [left ventricular ejection fraction (LVEF), estimated systolic pulmonary artery pressure (sPAP)], cardiac biomarkers (NT-proBNP, MR-proANP, hsTnT), renal markers [eGFR, creatinine, albuminuria, albumin-to-creatinine ratio (ACR)], heart rate variability (HRV), and renal CT densitometry. All markers were standardized (z-scores, higher values = worse). Subprofiles were generated and aggregated into three integrated profiles (cardiac, renal, pulmonary). Within-group dynamics were analyzed using the Wilcoxon signed-rank test (year-to-year deltas), between-group comparisons with the Mann–Whitney U test, effect sizes via Cliff’s delta, and multiple testing correction with the Benjamini–Hochberg false discovery rate (FDR). Results: Exercise tolerance declined in both groups: by 2025, 6MWT distance decreased by −10 m in SSc-ILD (p = 0.006; q = 0.010) and −20 m in COPD (p = 0.002; q = 0.004); post-exercise SpO2 fell in both cohorts (both p < 0.001; q < 0.001). MR-proANP remained consistently higher in SSc-ILD across all years (p ≤ 0.005; q ≤ 0.028). sPAP increased in both groups, reaching higher values in COPD by 2025 (p = 0.007; q = 0.033). NT-proBNP and hsTnT increased over time, while eGFR declined, and ACR rose in both cohorts (both p < 0.001; q < 0.001). HRV (HF/total power) decreased by 2025. Composite profiles showed: in 2023, the cardiac profile was worse in SSc-ILD (δ ≈ 0.27; p = 0.011; q = 0.048), but differences diminished by 2025; the renal profile was initially worse in SSc-ILD but later shifted unfavorably in COPD; the pulmonary profile showed no consistent between-group differences. Conclusions: Over three years, patients with SSc-ILD and COPD exhibited concordant deterioration in pulmonary, cardiac, and renal function. Distinct leading markers emerged: desaturation during exercise and neurohormonal activation (MR-proANP) in SSc-ILD, versus reduced 6MWT and higher sPAP in COPD. These findings support the need for integrated monitoring of the cardio–pulmo–renal continuum. Limitations include the observational design, multiple comparisons, and absence of advanced repeated-measures modeling.

1 January 2024 in Problems of Nutrition
Verified
Journal Article
Open access
LILyazat Ibrayeva
Lyazat Ibrayeva
DRDina Rybalkina
Dina Rybalkina
AAAssel Alina
Assel Alina
BIBacheva Irina
Bacheva Irina
MAMeruyert Aubakirova
Meruyert Aubakirova
POP.V. Ovtsynov
P.V. Ovtsynov
Биоимпедансометрия у пациентов с хроническими заболеваниями легких в контексте пульмокардиоренального континуума

4 February 2025 in Научно — практический журнал Фтизиопульмонология
Verified
Journal Article
Closed access
LIL.K. Ibrayeva
L.K. Ibrayeva
OKOlga Klassen
Olga Klassen
AAA.R. Alina
A.R. Alina
IBI.V. Bacheva
I.V. Bacheva
ANA.A. Nygimetova
A.A. Nygimetova
Resume: The first quarter of the 21st century is nearly complete, and the medical community increasingly faces the challenges of global population aging and the steady rise in chronic disease prevalence. It is evident that the complete or partial loss of function in one organ affects the status of others. The kidneys and lungs jointly regulate fluid homeostasis, acidbase balance, immune response, and the production of biologically active molecules. For instance, renal insufficiency leads to fluid overload and hypertension, thereby exacerbating disease severity and increasing mortality in patients with chronic lung diseases, such as interstitial lung diseases and COPD. At the same time, chronic lung diseases significantly affect kidney health, both through hypoxia and nephrotoxic effects of treatments. Rheumatic diseases, such as systemic sclerosis, should be specifically highlighted, as fibrosis develops in both organs. Understanding inter-organ interactions is crucial for preventing complications and improving survival. These factors underscore the necessity of recognizing these interrelations when selecting treatment strategies. Ideally, a multidisciplinary approach should be employed, involving specialists in pulmonology, nephrology, and rheumatology. Collaborative efforts will enable proper treatment, timely detection, and prevention of complications. Applying knowledge of inter-organ relationships will not only improve the quality of medical care but also reduce the financial burden on the healthcare system. This review attempts to describe the mechanisms linking kidney damage and pulmonary dysfunction, with a focus on chronic kidney disease (CKD) and its impact on lung health. It emphasizes the importance of early detection of CKD and outlines potential biomarkers for assessing damage to both organs, as well as therapeutic targets. The search was conducted in electronic databases such as Scopus, Web of Science, PubMed, and Google Scholar, using relevant keywords: «COPD and CKD,» «ILD and CKD», «Kidney function and lung function,» «Renal dysfunction and respiratory failure.» The search span was 15 years, from 2009 to 2024, and included only open-access articles in English, encompassing all types of studies, focusing solely on adults and animal studies. Pediatric studies were excluded from consideration.