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Effects of low‐dose l ‐arginine on insulin‐mediated vasodilatation and insulin sensitivity
Author(s) -
WASCHER T. C.,
GRAIER W. F.,
DITTRICH P.,
HUSSAIN M. A.,
BAHADORI B.,
WALLNER S.,
TOPLAK H.
Publication year - 1997
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1046/j.1365-2362.1997.1730718.x
Subject(s) - insulin , insulin sensitivity , vasodilation , arginine , medicine , endocrinology , pancreatic hormone , chemistry , pharmacology , insulin resistance , biochemistry , amino acid
The present study was carried out to evaluate the effect of a low‐dose intravenous supplementation of l ‐arginine on insulin‐mediated vasodilatation and insulin sensitivity. The study was performed in healthy subjects ( n = 7) and patients with obesity ( n = 9) and non‐insulin‐dependent diabetes mellitus (NIDDM) ( n = 9). Insulin‐mediated vasodilatation was measured by venous occlusion plethysmography during the insulin suppression test, evaluating insulin sensitivity. Experiments were performed twice in each subject in the presence or absence of a concomitant infusion of l ‐arginine (0.52 mg kg −1 min −1 ). l ‐Arginine restored the impaired insulin‐mediated vasodilatation observed in obesity (22.4 ± 4.1%, P < 0.01 vs. without l ‐arginine) and NIDDM (20.3 ± 3.2%, P < 0.01 vs. without l ‐arginine). In healthy subjects, no effect on insulin mediated‐vasodilatation was observed (24.8 ± 3.1% vs. 21.4 ± 3.1%). Insulin sensitivity was improved significantly ( P < 0.001) in all three groups by infusion of l ‐arginine. No effect of l ‐arginine was observed on insulin, insulin‐like growth factor I (IGF‐I), free fatty acids (FFAs) or C‐peptide levels during the insulin suppression test. Our data indicate that defective insulin‐mediated vasodilatation in obesity and NIDDM can be normalized by intravenous l ‐arginine. Furthermore, l ‐arginine improves insulin sensitivity in obese patients and NIDDM patients as well as in healthy subjects, indicating a possible mechanism that is different from the restoration of insulin‐mediated vasodilatation.