George Kalamaras

Dr. George Kalamaras


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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3 January 2020 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
Athanasia PatakaAthanasia Pataka
Athanasia Pataka
Serafeim - Chrysovalantis KotoulasSerafeim - Chrysovalantis Kotoulas
Serafeim - Chrysovalantis Kotoulas
GKGeorge Kalamaras
George Kalamaras
SSSophia Schiza
Sophia Schiza
KSKonstantinos Sapalidis
Konstantinos Sapalidis
CKChristoforos S. Kosmidis
Christoforos S. Kosmidis
Background: Gender affects the clinical presentation of obstructive sleep apnea (OSA). The classic OSA symptoms, such as sleepiness, snoring, and apnea, are not so frequent in women. Objectives: To evaluate possible gender differences in questionnaires used for OSA prediction, such as the Epworth Sleepiness Scale (ESS), STOP, STOP Bang (SB), Berlin Questionnaire (BQ), Athens Insomnia Scale (AIS), and Fatigue Scale (FS). Methods: 350 males were matched with 350 women referred to a sleep clinic, according to OSA severity. All responded to the questionnaires and underwent a sleep study. Cardiovascular disease (CVD) patients were separately analyzed. Results: ESS did not differ between genders. SB was higher in males, whereas STOP, BQ, AIS, and FS were higher in females. BQ presented the highest sensitivity in both genders, whereas STOP exhibited the highest specificity in males and ESS in females. AIS and FS were more sensitive and SB more specific in females, whereas BQ was more specific in males. For severe OSA, the predictive values of SB and BQ were almost similar for both genders; however AIS and FS were higher in women. CVD patients presented higher scores, independent of gender, except for AIS, which was higher in females. Conclusion: Gender-specific evaluation of questionnaires is necessary to prevent OSA under-diagnosis.

20 October 2021 in Medicina
Verified
Journal Article
Open access
PDF file
DIDespoina Ioannidou
Despoina Ioannidou
GKGeorge Kalamaras
George Kalamaras
Serafeim - Chrysovalantis KotoulasSerafeim - Chrysovalantis Kotoulas
Serafeim - Chrysovalantis Kotoulas
Athanasia PatakaAthanasia Pataka
Athanasia Pataka
Background and Objectives: Studies have tried to establish a relationship between Obstructive Sleep Apnea syndrome (OSA) and smoking but data still remain controversial. We aimed: 1. To evaluate the relationship between smoking and OSA; 2. To explore potential differences according to gender, and 3. To analyze the prevalence of cardiovascular disease (CVD) co-morbidities according to gender and smoking status. Materials and Methods: This retrospective study included 3791 (70.6% males) adult patients who visited a Sleep Clinic. All participants underwent nocturnal polysomnography. Daytime somnolence and insomnia were assessed by using the Epworth Sleepiness Scale (ESS) and the Athens Insomnia Scale (AIS). Ever-smokers completed the Fagerstrom Test for Nicotine Dependence (FTND). Results: OSA was confirmed in 72.1% of participants with 62.2% suffering from moderate-to-severe disease. The number of cigarettes/day, Pack/Years, and FTND were significantly higher in patients with more severe OSA. The prevalence of current smokers was higher in those without OSA or with mild disease, whereas the prevalence of former smokers was higher in moderate and severe OSA. In univariate analysis, current smokers were found to be 1.2 times more likely to have OSA compared with never and former smokers combined and former smokers 1.49 times more likely compared with never smokers. In the multiple regression analysis, after adjusting for BMI, gender, age and number of alcoholic drinks per week, smoking was not found to be significantly associated with OSA. In gender stratified multivariate analyses, no significant associations were observed. CVD co-morbidities were more frequent in more severe OSA. Hypertension, coronary disease and diabetes were more prevalent in former smokers with AHI ≥ 15, compared with current smokers, especially in men. Conclusions: Even if an independent effect of smoking on OSA was not found, the number of cigarettes/day, Pack/Years, and FTND were higher in patients with more severe OSA with more prevalent CVD co-morbidities.

31 August 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
Athanasia PatakaAthanasia Pataka
Athanasia Pataka
Serafeim - Chrysovalantis KotoulasSerafeim - Chrysovalantis Kotoulas
Serafeim - Chrysovalantis Kotoulas
GKGeorge Kalamaras
George Kalamaras
ATAsterios Tzinas
Asterios Tzinas
IGIoanna Grigoriou
Ioanna Grigoriou
PAParaskevi Argyropoulou
Paraskevi Argyropoulou
The connection between smoking and Obstructive sleep apnea (OSA) is not yet clear. There are studies that have confirmed the effect of smoking on sleep disordered breathing, whereas others did not. Nicotine affects sleep, as smokers have prolonged total sleep and REM latency, reduced sleep efficiency, total sleep time, and slow wave sleep. Smoking cessation has been related with impaired sleep. The health consequences of cigarette smoking are well documented, but the effect of smoking cessation on OSA has not been extensively studied. Smoking cessation should improve OSA as upper airway oedema may reduce, but there is limited data to support this hypothesis. The impact of smoking cessation pharmacotherapy on OSA has been studied, especially for nicotine replacement therapy (NRT). However, there are limited data on other smoking cessation medications as bupropion, varenicline, nortriptyline, clonidine, and cytisine. The aim of this review was to explore the current evidence on the association between smoking and OSA, to evaluate if smoking cessation affects OSA, and to investigate the possible effects of different pharmacologic strategies offered for smoking cessation on OSA.

1 December 2021 in Sleep Medicine
Verified
Journal Article
Closed access
Athanasia PatakaAthanasia Pataka
Athanasia Pataka
Christos A. FrantzidisChristos A. Frantzidis
Christos A. Frantzidis
GKGeorge Kalamaras
George Kalamaras
PGPolyxeni Gkivogkli
Polyxeni Gkivogkli
Serafeim - Chrysovalantis KotoulasSerafeim - Chrysovalantis Kotoulas
Serafeim - Chrysovalantis Kotoulas
PANAGIOTIS BAMIDISPANAGIOTIS BAMIDIS
PANAGIOTIS BAMIDIS

8 December 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
Athanasia PatakaAthanasia Pataka
Athanasia Pataka
Serafeim - Chrysovalantis KotoulasSerafeim - Chrysovalantis Kotoulas
Serafeim - Chrysovalantis Kotoulas
AKAliki Karkala
Aliki Karkala
ATAsterios Tzinas
Asterios Tzinas
GKGeorge Kalamaras
George Kalamaras
ESEmiliza Stefanidou
Emiliza Stefanidou
Tobacco smoking has been a recognized risk factor for cardiovascular diseases (CVD). Smoking is a chronic relapsing disease and pharmacotherapy is a main component of smoking cessation. Obstructive sleep apnea (OSA) and smoking both increase the risk of CVD and are associated with significant morbidity and mortality. There are few existing data examining how pharmacological treatment, such as nicotine replacement therapy (NRT), bupropion, and varenicline, affect smokers suffering with OSA and especially their cardiovascular effects. The aim of this review was to evaluate the effects of smoking cessation pharmacotherapy on OSA with a special emphasis on the cardiovascular system. Results: Only small studies have assessed the effect of NRTs on OSA. Nicotine gum administration showed an improvement in respiratory events but with no permanent results. No specific studies were found on the effect of bupropion on OSA, and a limited number evaluated varenicline’s effects on sleep and specifically OSA. Varenicline administration in smokers suffering from OSA reduced the obstructive respiratory events, especially during REM. Studies on second-line medication (nortriptyline, clonidine, cytisine) are even more limited. There are still no studies evaluating the cardiovascular effects of smoking cessation medications on OSA patients. Conclusions: Sleep disturbances are common withdrawal effects during smoking cessation but could be also attributed to pharmacotherapy. Smokers should receive personalized treatment during their quitting attempts according to their individual needs and problems, including OSA. Future studies are needed in order to evaluate the efficacy and safety of smoking cessation medications in OSA patients.

1 October 2022 in BMC Medical Informatics and Decision Making
Verified
Journal Article
Open access
PDF file
VDVlasios K. Dimitriadis
Vlasios K. Dimitriadis
CAChristina Alexopoulou
Christina Alexopoulou
AAAnastasia Amfilochiou
Anastasia Amfilochiou
PSPaschalis Steiropoulos
Paschalis Steiropoulos
GTGeorgia Trakada
Georgia Trakada
PNPantelis Natsiavas
Pantelis Natsiavas
Background: Chronic respiratory conditions are a prominent public health issue and thus, building a patient registry might facilitate both policy decision making and improvement of clinical management processes. Hellenic Registry of patients with Home Mechanical Ventilation (HR-HMV) was initiated in 2017 and a web-based platform is used to support patient data collection. Eighteen hospital departments (including sleep labs) across Greece participate in this initiative, focusing on recording data for both children and adult patients supported by mechanical ventilation at home, including patients with Sleep Apnea–Hypopnea Syndrome (SAHS) under Positive Airway Pressure (PAP) therapy. Methods: The HR-HMV initiative ultimately aims to provide a database for evidence-based care and policy making in this specific domain. To this end, a web information system was developed and data were manually collected by clinics and hospital departments. Legal and privacy issues (such as General Data Protection Rule compliance and technical information security measures) have been considered while designing the web application. Based on the collected data, an exploratory statistical report of SAHS patients in Greece is presented. Results: Eleven out of the eighteen participating clinics and hospital departments have contributed with data by the time of the current study. More than 5000 adult and children patient records have been collected so far, the vast majority of which (i.e., 4900 patients) diagnosed with SAHS. Conclusion: The development and maintenance of patient registries is a valuable tool for policy decision making, observational/epidemiological research and beyond (e.g., health technology assessment procedures). However, as all data collection and processing approaches, registries are also related with potential biases. Along these lines, strengths and limitations must be considered when interpreting the collected data, and continuous validation of the collected clinical data per se should be emphasized. Especially for Greece, where the lack of national registries is eminent, we argue that HR-HMV could be a useful tool for the development and the update of related policies regarding the healthcare services for patients with home mechanical ventilation support and SAHS patients, which could be useful for related initiatives at a European level as well.