Relationships between metabolic clearance rate of insulin and body mass index in a female population ranging from anorexia nervosa to severe obesity
Castillo, M.J.; Scheen, A.J.; Jandrain, B.; Lefèbvre, P.J.
International Journal of Obesity and Related Metabolic Disorders Journal of the International Association for the Study of Obesity 18(1): 47-53
1994
ISSN/ISBN: 0307-0565 PMID: 8130815 Document Number: 437822
Changes in the metabolic clearance rate of insulin (MCR-I) have been described in several pathological conditions. Conflicting data suggest that they may be related to either body mass index (BMI) or body composition. This study aimed to investigate the relationship between the MCR-I and BMI in an exclusively female population showing a wide range of BMI. For that purpose, hyperinsulinemic normoglycemic glucose clamps were performed in nine anorectic subjects (BMI: 14.5 +- 0.8 kg/m-2), 11 healthy volunteers (BMI: 20.3 +- 0.5 kg/m-2) and 12 obese patients (BMI: 33.0 +- 0.9 kg/m-2). To exclude any influence of the menstrual cycle on the MCR-I, five healthy women underwent three tests at different days of the menstrual cycle: menstruation period, late follicular pre-ovulatory phase and luteal phase, in random order. The MCR-I, which was quite reproducible in a given subject, was not significantly modified by the menstrual cycle. In the premenopausal female population studied, the mean (+- s.e.m.) MCR-I normalized for body weight (kg) were 35.4 +- 3.4, 24.7 +- 1.8 and 14.0 +- 1.0 ml/kg/min (P lt 0.01) for anorectic subjects, healthy volunteers and obese patients, respectively. These differences were maintained when the MCR-I was normalized according to corporeal surface (m-2) (1018 +- 75, 859 +- 67, 638 +- 40 ml/m-2/min, P lt 0.01) or lean body mass (kg) (37.1 +- 3.4, 32.6 +- 2.7 and 24.1 +- 0.5 ml/kg-LBM/min, P lt 0.01), but disappeared when MCR-I was expressed per kg of ideal body weight (24.6 +- 2.2, 24.6 +- 2.1 and 22.4 +- 1.4 ml/kg-IBW/min, n.s.). There was a significant negative correlation between MCR-I and BMI whatever the mode of expression of MCR-I, i.e. body weight (kg) (r = -0.785, P lt 0.001), corporeal surface (m-2) (r = -0.619, P lt 0.001) or lean body mass (kg) (r = -0.543, P lt 0.01). This correlation was not statistically significant when the MCR-I was expressed per kg of ideal body weight (r = -0.121). The MCR-I was also significantly correlated to both basal plasma insulin levels (r = -0.400, P lt 0.05) and glucose metabolic clearance rate (MCR-G), as an index of insulin sensitivity, obtained in the clamp (r = -0.622, P lt 0.001). These results suggest that differences in insulin metabolism are linked to differences in body weight by a still unknown mechanism and that variations in insulin metabolism may partly account for differences in circulating insulin levels.