| Abstract | Ciljevi istraživanja: Ispitati razlike u kliničkim obilježjima i globalnoj DNA-metilaciji u bolesnika s KOPB-om iz dvaju zemljopisno različitih hrvatskih područja. Ustroj studije: Presječno istraživanje Ispitanici i metode: Uključeno je 136 bolesnika s KOPB-om i 64 kontrolna ispitanika obaju spolova starosti od 40 do 92 godine. Klinička i fenotipska obilježja KOPB-a analizirana su spirometrijom, bronhodilatacijskim testom, CT-om pluća, plućnom difuzijom, CAT-upitnikom, mMRC-skalom, laboratorijsko-dijagnostičkom obradom, EKG-om i UZV-om srca. Kvaliteta života ispitana je pomoću SF-36 i SGRQ upitnika. Globalna DNA-metilacija određivana je iz periferne krvi ispitanika. Rezultati: Usporedbom bolesnika nađeno je da su osječki bolesnici bitno više kašljali i iskašljavali (P < 0,001), imali teže stupnjeve zaduhe (P < 0,001), više kardiovaskularnih komorbiditeta (P < 0,001) i depresije (P = 0,01) u odnosu na zadarske bolesnike. Zadarski bolesnici češće su imali emfizem (P < 0,001) i blaže stupnjeve zaduhe (mMRC- 0, 1, 2) nego osječki bolesnici. Kvaliteta života osječkih bolesnika bila je lošija je u odnosu na zadarske bolesnike. Globalna DNA-metilacija nije se bitno razlikovala između bolesnika s KOPB-om i kontrolne skupine te između osječkih i zadarskih bolesnika. Bolesnici s KOPB-om, pušači te ispitanici iz Osijeka imali su niže vrijednosti globalne DNA-metilacije. Bitna razlika u globalnoj DNA-metilaciji nađena je samo u zadarskih ispitanika, između bolesnika i kontrolne skupine u skupini svih ispitanika (P = 0,02) i skupini muškaraca (P = 0,03), te između aktivnih pušača, bivših pušača i nepušača (P = 0,01). Bitna razlika u DNA-metilaciji između osječkih i zadarskih ispitanika nađena je u skupini kontrolnih ispitanika (P = 0,001). Vrijednosti globalne DNA-metilacije, razvrstane u dva klastera, pokazale su da je klaster 2 (visokometilirana DNA) bitno manje zastupljen od klastera 1 (niskometilirana DNA) i pretežno nađen u zadarskih ispitanika. S obzirom na pripadnost klasteru, bolesnici s KOPB-om su se bitno razlikovali prema pušenju (P = 0,03), pušačkim godinama (P = 0,002), kašlju (P = 0,001), iskašljavanju (P = 0,01) i zadusi u naporu (P = 0,007). Globalna hipometilacija DNA bila je zastupljenija u bolesnika koji su kašljali (P = 0,04), te manje zastupljena u bolesnika s depresijom (P = 0,04). Vrijednosti globalne DNA-metilacije ≤ 2,8 ukazuju na veću vjerojatnost kašlja (P = 0,04) i pušački indeks ≥ 20 PY (P = 0,009). Zaključak: Razlike u kliničkim obilježjima bolesnika s KOPB-om u kontinentalnoj i primorskoj Hrvatskoj povezane su kako s okolišnim čimbenicima rizika tako i zaštitnim učincima okoliša. Ovim istraživanjem nije potvrđeno da je određivanje globalne DNA-metilacije prikladan i pouzdan biomarker u KOPB-u, ali ima naznaka da bi ona mogla biti važna kao epigenetički marker u nekim karakteristikama kao što je su pušenje i kašalj. |
| Abstract (english) | Research objectives: To examine the differences in the clinical characteristics and global DNA methylation in patients with COPD from two geographically different Croatian regions. Study-design: Cross-sectional research Subjects and methods: 136 COPD patients and 64 control subjects of both sexes aged 40-92 were included. Clinical and phenotypic characteristics of COPD were analyzed by spirometry, bronchodilation test, lung CT, pulmonary diffusion, CAT questionnaire, mMRC-scale, laboratory-diagnostic processing, ECG and ultrasound of the heart. Quality of life was examined by using the SF-36 and SGRQ questionnaire. Global DNA methylation was determined from the subjects' peripheral blood. Results: By comparing the patients, it was found that patients from Osijek coughed harder and expectorated (P<0.001), had more severe degrees of shortness of breath (P<0.001), more cardiovascular comorbodities (P<0.001) and depression (P=0.01), compared to Zadar patients. Patients from Zadar more often had emphysema (P<0.001) and milder degrees of dyspnea (mMRC- 0, 1, 2), than patients from Osijek. The quality of life of Osijek patients was worse compared to Zadar patients. Global DNA methylation did not significantly differ from COPD and controls, and between patients from Osijek and Zadar. Patients with COPD, smokers and subjects from Osijek had lower values of global DNA methylation. A significant difference in global DNA methylation was found only in subjects from Zadar, between patients and controls in the group of all subjects (P=0.02) and the group of men (P=0.03), and between smokers, ex-smokers and non-smokers. A significant difference in DNA methylation between subjects from Osijek and Zadar was found in control subjects (P=0.001). Global DNA methylation values, classified into two clusters, showed that cluster-2 (low-methylated DNA) was significantly less represented than culster-1 (high-methylated DNA), and was predominantly found in Zadar subjects. Considering the cluster membership, patients with COPD differed significantly according to smoking (P=0.03), smoking years (P=0.002), cough (P=0.001), expectoration (P=0.01) and shortness of breath in exertion (P=0.007). Global hypomethylation of DNA was more common in patients who coughed (P=0.04), and less common in patients with depression (P=0.04). Global DNA-methylation values of ≤ 2.8 indicate a higher probability of cough (P=0.04) and a smoking index greater than ≤ 20 PY (P=0.009). Conclusion: Differences in the clinical features of COPD are associated with enviromental risk factors and protective effects of the environment in coastal versus continental Croatia. This research did not confirm that the determination of global DNA methylation is a suitable and reliable biomarker in COPD, but there are indications that it could be important as an epigenetic marker in some characteristics of the disease such as smoking and cough. |
