Abstract
Objective: Adrenomedullin (AM) is a potent hypotensive peptide which may be implicated in the
insulin regulatory system. Acute hyperinsulinemia exerts no influence on plasma AM
in normal subjects while no data on obese subjects has been reported.
Purpose: The aim of the study was to investigate the effect of acute hyperinsulinemia on the
plasma AM concentration in patients with uncomplicated obesity.
Research Methods: We measured the plasma AM levels in 23 obese subjects (BMI 41.9 ± 9.8 kg/m2 ), 21 females and 2 males (mean age 31 ± 7.2 years), before and during a euglycemic
hyperinsulinemic clamp. The control group consisted of 43 healthy subjects (HS) (22
males and 21 females; mean age 38 ± 12 years; BMI 23.3 ± 3.2 kg/m2 ).
Results: Baseline plasma AM was found to be higher in obese subjects (20.4 ± 8.4 pg/ml) than
in normal subjects (11.3 ± 0.8 pg/ml) (p < 0.001). A significant increase in the
plasma AM levels was observed in obese subjects during acute hyperinsulinemia (from
20.4 ± 8.4 pg/ml at 0 min to 26 ± 8.9 pg/ml at 120 min, p < 0.02). Plasma AM concentrations
were significantly correlated with insulin levels at 30 min (r = 0.44; p = 0.04) and
120 min (r = 0.40, p = 0.05) during the clamp.
Discussion: In conclusion, acute hyperinsulinemia induced a significant increase in the plasma
levels of AM in uncomplicated obese subjects. Hyperinsulinemia may, at least in part,
regulate levels of AM in obesity, explaining the high levels of the peptide in these
subjects.
Key words
Adrenomedullin - euglycemic hyperinsulinemic clamp
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Prof. M.D. Claudio Letizia
Dept. Scienze Cliniche Policlinico Umberto I
Viale del Policlinico 155
00156 Roma
Italy
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eMail: claudio.letizia@uniroma1.it