Author contributions:
1) Kanelina Bimpa: conception and design, administrative support, provision of study materials or patients, collection and assembly of data, data analysis and interpretation, manuscript writing, final approval of manuscript
2) Theodosia Charitou: conception and design, provision of study materials or patients, collection and assembly of data, manuscript writing, final approval of manuscript
3) Apostolos C. Ziogas: collection and assembly of data, data analysis and interpretation, manuscript writing, final approval of manuscript, manuscript submission
4) Konstantinos Kantounis: conception and design, administrative support, provision of study materials or patients, collection and assembly of data, final approval of manuscript
5) Emmanouil Xydias: collection and assembly of data, data analysis and interpretation, manuscript writing, final approval of manuscript
6) Mattheos Bobos: conception and design, provision of study materials or patients, collection and assembly of data, manuscript writing, final approval of manuscript
7) Elias Tsakos: administrative support, provision of study materials or patients, collection and assembly of data, data analysis and interpretation, final approval of manuscript