BACKGROUND: Elevated pregnancy-associated plasma protein A (PAPP-A) levels are associated with increased risk of death in ischemic heart disease as well as in hemodialysis patients. Previous research indicates that the prognostic value of PAPP-A may be stronger in patients with concomitant diabetes mellitus or signs of inflammation. We studied the association between PAPP-A and outcomes in prevalent hemodialysis patients and hypothesized that diabetes mellitus and inflammation status act as effect modifiers.
MATERIALS AND METHODS: Circulating PAPP-A levels were quantified using ELISA. Cox proportional hazards- and quantile regression models were used for associations between PAPP-A and mortality. PAPP-A levels were log-transformed for Normality.
RESULTS: During 60 months follow-up, 37 (40%) of the 92 participants died. Higher PAPP-A was associated with increased risk of mortality in unadjusted analysis (HR per SD = 1.4, 95% CI = 1 - 1.9, p = 0.03) and when adjusted for confounders and cardiovascular risk factors (HR = 1.8, 95% CI = 1.18-2.73, p = 0.006). An interaction between PAPP-A levels and diabetes mellitus on mortality was found (HR for the multiplicative interaction term = 2.74 95% CI = 1.02-7.37, p = 0.05). In a quantile regression adjusted for age and sex, one SD increase of PAPP-A was associated with 22 months shorter estimated time until 25% of the patients died (95% CI -35 to -9.1 months).
CONCLUSIONS: Increased PAPP-A levels are associated with higher all-cause mortality in prevalent hemodialysis patients with concomitant diabetes mellitus.