Plasma stem cell factor levels are associated with risk of cardiovascular disease and death

Objective. Stem cell factor (SCF) is a key growth factor for several types of stem and progenitor cells. There is experimental evidence that such cells are of importance for maintaining the integrity of the cardiovascular system. We investigated the association between circulating levels of SCF and risk for development of cardiovascular events and death. Methods. SCF was analysed by the proximity extension assay technique in plasma from 4742 subjects participating in the Malmo Diet and Cancer Study. Cardiovascular events and death were monitored through national registers with a mean follow-up time of 19.2 years. Results. Subjects with high baseline levels of SCF had lower cardiovascular (n = 340) and all-cause mortality (n = 1159) as well as a lower risk of heart failure (n = 177), stroke (n = 318) and myocardial infarction (n = 452). Smoking, diabetes and high alcohol consumption were associated with lower levels of SCF. Single nucleotide polymorphisms in the gene region encoding PDX1 C-terminal inhibiting factor 1 (PCIF1) and matrix metalloproteinase-9 were associated with plasma SCF levels. The highest SCF quartile remained independently associated with a lower risk of a lower risk of cardiovascular [hazard ratio and 95% confidence interval 0.59 (0.43-0.81)] and all-cause mortality [0.68 (0.57-0.81)], heart failure [0.50 (0.31-0.80)] and stroke [0.66 (0.47-0.92)], but not with MI [0.96 (0.72-1.27)] as compared with the lowest quartile when adjusting for traditional cardiovascular risk factors in Cox proportional hazard regression models. Conclusions. This prospective population-based study demonstrates that subjects with high levels of SCF have a lower risk of cardiovascular events and death. The findings provide clinical support for a protective role of SCF in maintaining cardiovascular integrity.