NT-pro-BNP during hypoglycemia and hypoxemia in normal subjects: impact of renin-angiotensin system activity.
Brain-derived natriuretic peptide (BNP) is a cardioprotective peptide released, together with the inactive NH(2)-terminal part of its prohormone (NT-pro-BNP), in response to different kinds of myocardial stress. Hypoglycemia and hypoxemia are conditions that threaten cellular function and hence potentially stimulate BNP release. BNP interacts with the renin-angiotensin system (RAS). The aim of this study was, therefore, to explore if basal RAS activity has an impact on NT-pro-BNP concentrations during myocardial stress induced by hypoglycemia and hypoxemia. From a cohort of 303 healthy young men, 10 subjects with high-RAS activity and 10 subjects with low-RAS activity (age 26 +/- 1 yr; mean +/- SE) were studied in a single-blinded, randomized, counterbalanced, crossover study on three occasions separated by at least 3 wk: 1) hypoglycemia (mean nadir plasma glucose 2.7 +/- 0.5 mmol/l), 2) hypoxemia (mean nadir Po(2) 5.8 +/- 0.5 kPa), and 3) normoglycemic normoxia (control). NT-pro-BNP was measured at baseline, during the stimuli, and in the recovery phase. Hypoxemia was associated with a 9% increase in NT-pro-BNP from 2.2 +/- 1.5 pmol/l at baseline to 2.4 +/- 1.5 pmol/l during hypoxemia (P < 0.001). Hypoglycemia did not affect the NT-pro-BNP level. RAS activity had no impact on NT-pro-BNP levels during hypoglycemia and hypoxemia. Hypoxemia, but not hypoglycemia, stimulates NT-pro-BNP. This indicates that cardiac defense mechanisms against hypoglycemia, if any, are probably different from those against hypoxemia. Basal RAS activity had no impact on NT-pro-BNP levels.
Due-Andersen
R
R
Endocrinology Section, Division of Internal Medicine I, Hillerød Hospital, Helsevej 2, DK-3400 Hillerød, Denmark. rsa@noh.regionh.dk
Pedersen-Bjergaard
U
U
Høi-Hansen
T
T
Olsen
N V
NV
Kistorp
C
C
Faber
J
J
Boomsma
F
F
Thorsteinsson
B
B
D000328:Adult; D000804:Angiotensin II / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D018592:Cross-Over Studies; D006801:Humans; D007003:Hypoglycemia / Q000139:chemically induced / Q000378:metabolism*; D007004:Hypoglycemic Agents; D000860:Hypoxia / Q000378:metabolism*; D007328:Insulin; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D012016:Reference Values; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000502:physiology*
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D000804:Angiotensin II; D020097:Natriuretic Peptide, Brain; D012083:Renin