Serum zinc concentration and quality of life in chronic liver diseases

Health related quality of life (HRQOL) in chronic liver disease (CLD) patients has been attracting much attention these days because it is closely associated with clinical outcomes in CLD patients. HRQOL has become established as an important concept and target for research and practice in the fields of medicine. A critique of HRQOL research is the lack of conceptual clarity and a common definition of HRQOL. Using a clear definition of HRQOL may increase the conceptual understanding. In this study, we aimed to elucidate the association between serum zinc (Zn) level and HRQOL as assessed by the Beck Depression Inventory-2nd edition (BDI-II), Pittsburgh Sleep Quality Index Japanese version (PSQI-J) and the 36-Item Short Form Health Survey (SF-36) in CLD patients (n = 322, median age = 65 years, 121 liver cirrhosis (LC) patients (37.6%)). The median serum Zn level for all cases was 73.2 μg/dl. The median BDI-II score and PSQI-J score were 6 and 5, respectively. Patients with higher BDI-II score tended to have lower serum Zn level compared with those with lower BDI-II score. Similar tendencies were observed in patients with higher PSQI-J score. In the SF-36, physical functioning, role physical and physical component summary score significantly correlated with serum Zn level regardless of age, liver disease etiology and the LC status. While mental health and mental component summary score did not significantly correlate with serum Zn level regardless of age, liver disease etiology and the LC status. In conclusion, serum Zn level can be a useful marker for decreased HRQOL in patients with CLDs, especially for physical components.