Distribution and Correlates of Midregional Proadrenomedullin in the General Population

Adrenomedullin (ADM)1 is a multifunctional peptide hormone expressed in most tissues and in multiple cell types in response to cellular stress, ischemia, and hypoxia. These characteristics indicate that ADM may have a role in protection against cellular injury and therefore is a promising biomarker of disease (1). Increased ADM concentrations have been reported in multiple diseases; however, the results between studies have been inconsistent, perhaps owing to technical difficulties in measuring ADM (2). To overcome these problems a novel assay has been developed. This assay reflects ADM production by measurement of midregional proadrenomedullin (MR-proADM), a separate fragment of the precursor peptide preproadrenomedullin. MR-proADM, which has no known function and is produced in a 1:1 stoichiometry to ADM. The MR-proADM assay has been shown to exhibit low intraassay variability, and concentrations of MR-proADM appear stable in samples that are stored at room temperature for up to 72 h, undergo multiple freeze-thaw cycles, or are drawn from patients in a nonfasting state (2). We used the previously described immunoluminometric sandwich assay (2) (Brahms) to measure MR-proADM in 5258 fasting individuals from the cardiovascular cohort of the population-based Malmo Diet and Cancer Study who attended a baseline visit between 1991 and 1996 (3). We studied the relation of MR-proADM with 23 other baseline variables (Table …