Plasma Midregional Pro-atrial Natriuretic Peptide Is Associated With Blood Pressure Indices and Hypertension Severity in Adults With Hypertension

BACKGROUND Midregional pro-atrial natriuretic peptide (MR-proANP) is a newly described stable fragment of the N-terminal part of pro-atrial natriuretic peptide. We tested the hypothesis that in adults with essential hypertension, plasma levels of MR-proANP would be associated with systolic blood pressure (SBP), pulse pressure, and hypertension severity. METHODS Participants included 1,034 African Americans (65 +/- 9 years, 72% women) and 880 non-Hispanic whites (61 +/- 9 years, 55% women) belonging to sibships ascertained on the basis of hypertension. MR-proANP was measured by an immunoluminometric assay. Hypertension severity was based on number of hypertension medication classes used and multiples of SBP and diastolic blood pressure (DBP) deviations from 120/70 mm Hg. Generalized estimating equations were used to assess whether plasma levels of MR-proANP were associated with SBP, pulse pressure, and hypertension severity independent of potential confounding variables. RESULTS In African Americans, after adjustment for age, sex, body mass index, estimated glomerular filtration rate (eGFR), smoking history, diabetes, total cholesterol, high-density lipoprotein cholesterol, medication (beta-blocker, statin, and aspirin) use, and previous history of myocardial infarction or stroke, higher MR-proANP levels were significantly associated with greater SBP (P < 0.0001), pulse pressure (P < 0.0001), and hypertension severity (P = 0.0013). The associations were replicated in non-Hispanic whites; after adjustment for the above variables, higher MR-proANP levels were significantly associated with greater SBP (P = 0.013), pulse pressure (P = 0.0006), and hypertension severity (P = 0.028). CONCLUSION Plasma MR-proANP may be a marker of arterial stiffness and severity of hypertension in adults with hypertension.