ABSTRACT
Objective:To investigate the relationship between the number of epithelial progenitor cells(EPCs)in peripheral blood and blood parameter values in order to clarify the relationship between peripheral blood EPCs and the length of survival in elderly individuals aged 75 and beyond.Methods:Analysis was conducted on 114 individuals ≥75 years recruited from the Department of Geriatrics, Tianjin Medical University General Hospital in 2008.Clinical data were collected with December 31, 2020 as the end of the follow-up.Associations between peripheral blood EPC numbers, blood parameter values and all-cause mortality were analyzed.Results:In low and high EPC groups based on orthogonal partial least squares-discriminant analysis(OPLS-DA), D-Dimer was found to be a potential classification marker[the variable importance in projection(VIP)=4.750], out of a panel of blood tests.Blood parameters such as red blood cells(RBC), hemoglobin(HGB), hematocrit(HCT), aspartate aminotransferase(AST), gamma-glutamyl transferase(GGT), lactate dehydrogenase(LDH)and D-Dimer showed statistically significant differences between groups with different levels of EPCs(all P<0.05). Blood EPC numbers were positively correlated with RBC, HGB and HCT and negatively correlated with GGT and D-Dimer in older individuals( r=0.364, 0.343, 0.336, -0.312, -0.312, P<0.05 for all). The number of circulating EPCs had a significant positive correlation with survival time in older individuals( r=0.234, P=0.017). Based on the data of the long-term(12-years)follow-up, Logistic regression analysis suggested that the number of EPCs, age, and HCT were associated with all-cause mortality events in older individuals( OR=0.971, 1.585, 1.231, P=0.013, 0.012, 0.029). Conclusions:EPCs in the peripheral circulation may be involved in the progression of various conditions such as anemia, cardiac, hepatic and renal injury, and coagulation.The number of circulating EPCs may influence the survival of elderly individuals ≥75 years.Age and HCT may be risk factors for all-cause mortality events, whereas the number of EPCs may be a protective factor.