Impact of obesity on plasma natriuretic peptide levels.
BACKGROUND
The mechanisms linking obesity to hypertension have not been established, but sodium retention and excessive sympathetic tone are key contributors. The natriuretic peptides are important regulators of sodium homeostasis and neurohormonal activation, raising the possibility that obese individuals have an impaired natriuretic peptide response.


RESULTS
We examined the relations of plasma B-type natriuretic peptide (BNP) and N-terminal proatrial natriuretic peptide (N-ANP) to body mass index in 3389 Framingham Study participants (1803 women) without heart failure. Multivariable regression analyses were performed, adjusting for clinical and echocardiographic covariates. BNP levels below the assay detection limit and N-ANP levels in the lowest sex-specific quartile were categorized as low. Multivariable-adjusted mean plasma BNP levels in lean (<25 kg/m2), overweight (25 to 29.9 kg/m2), and obese (> or =30 kg/m2) men were 21.4, 15.5, and 12.7 pg/mL, respectively (trend P<0.0001). Corresponding values in women were 21.1, 16.3, and 13.1 pg/mL (trend P<0.001). A similar pattern was noted for plasma N-ANP. Obese individuals had higher odds of having low plasma BNP (multivariable-adjusted odds ratios: men, 2.51; 95% CI, 1.71 to 3.68; women, 1.84; 95% CI, 1.32 to 2.58) and low plasma N-ANP (odds ratios: men, 4.81; 95% CI, 2.98 to 7.76; women, 2.85; 95% CI, 2.01 to 4.04) compared with lean individuals. Diabetes also was associated with low plasma natriuretic peptide levels, and the negative effects of obesity and diabetes on natriuretic peptide levels were additive.


CONCLUSIONS
Obese individuals have low circulating natriuretic peptide levels, which may contribute to their susceptibility to hypertension and hypertension-related disorders.
Wang
Thomas J
TJ
Framingham Heart Study, Framingham, Mass 01702, USA.
Larson
Martin G
MG
Levy
Daniel
D
Benjamin
Emelia J
EJ
Leip
Eric P
EP
Wilson
Peter W F
PW
Vasan
Ramachandran S
RS
D009320:Atrial Natriuretic Factor / Q000097:blood*; D001824:Body Constitution; D015992:Body Mass Index; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D011498:Protein Precursors / Q000097:blood*
C099254:N-terminal proatrial natriuretic peptide; D011498:Protein Precursors; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor