Functional gastrointestinal disorders (FGID) are common class of disorders in gastroenterology. There is growing number of patients suffering from the FGIDs worldwide but is little known about actual causes and prevalence especially in developing countries. (1) The symptoms of FGIDs are heterogeneous, tend to come and go over time, and can overlap with many symptoms of other gastrointestinal disorders. Many patients state the worsening of the disease in stressful conditions, difficulties in work or marriage. There has been observed comorbidity with some other disorders of gastrointestinal tract but also with some non-gastrointestinal disorders. (2)
Visceral hypersensitivity is one of the major caracteristics of FGIDs. It usually manifests as pain associated with bowel disturbances. People with visceral hypersensitivity have reduced pain and discomfort thresholds.(3) There are several possible underlying mechanisms that have been proposed: subtle inflammation, psychosocial factors and altered sensorimotor function of the gut.(3) Visceral sensitivity index has been developed for measuring gastrointestinal symptom-specific anxiety (GSA) and accompanying hypersensitivity.(4) It was observed that gastrointestinal symptom-specific anxiety could be a significant predictor of gastrointestinal complaints and an important factor for quality of life in patients with IBS as well for gastrointestinal symptom severity. (5–6) Gastrointestinal-specific anxiety is also considered to be a mediator of the relationship between general psychological distress measures and gastrointestinal (GI) symptom severity. (7)
Clinical classification of FGIDs is mainly symptom based and in recent years much attention is paid on genetic research for identification of causative pathways and molecular basis.(8–10) The population of students is the healthiest segment of one society, but in recent years there has been a constant increase in their morbidity and mortality as well as of chronic diseases and disorders, deformities, growth and development disorders, injuries and mental health problems.(11) So called ”academic stress” can leave serious and long-term consequences including functional gastrointestinal disorders that are increasingly associated with populations exposed to stress.(12)
Stress is very often associated with various functional gastrointestinal disorders, so among the candidate genes associated with these disorders there are also genes whose products are involved in various physiological stress pathways and regulation of brain-gut axis. (12)
ACE gene encodes for angiotensin converting enzyme which is of vital importance for blood pressure regulation. ACE enzyme is involved in the conversion of angiotensin I to angiotensin II, physiologically active peptide and a potent vasoconstrictor that controls blood pressure and fluid-electrolyte balance.(13) Many other physiologic processes are affected by ACE and its peptide substrates and products.(13) Effects of angiotensin II are noticed on the vasculature, the heart, the kidney, the nervous system, metabolism, cell proliferation, and a lot of other processes.(13) Several studies have shown that ACE may also be involved in hypothalamic–pituitary–adrenal axis (HPA axis) regulation and catecholamine production by generation ATII and therefore required for sympatoadrenal activation during stress.(14)
The aim of this study was to explore the association between self-reported scores of Visceral Sensitivity Index questionnaire and the ACE genotype for rs1799752 (insertion/deletion in intron 16), among students exposed to psychological distress during the exam period.