Mitochondrial capacity is affected by glycemic status in young untrained women with type 1 diabetes but is not impaired relative to healthy untrained women

作者:Item Flurin; Heinzer Schweizer Susanne; Wyss Michael; Fontana Piero; Lehmann Roger; Henning Anke; Weber Markus; Boesiger Peter; Boutellier Urs; Toigo Marco*
来源:American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, 2011, 301(1): R60-R66.
DOI:10.1152/ajpregu.00747.2010

摘要

Item F, Heinzer-Schweizer S, Wyss M, Fontana P, Lehmann R, Henning A, Weber M, Boesiger P, Boutellier U, Toigo M. Mitochondrial capacity is affected by glycemic status in young untrained women with type 1 diabetes but is not impaired relative to healthy untrained women. Am J Physiol Regul Integr Comp Physiol 301: R60-R66, 2011. First published April 13, 2011; doi:10.1152/ajpregu.00747.2010.-In this study, we examined whether glycemic status influences aerobic function in women with type 1 diabetes and whether aerobic function is reduced relative to healthy women. To this end, we compared several factors determining aerobic function of 29 young sedentary asymptomatic women (CON) with 9 women of similar age and activity level with type 1 diabetes [DIA, HbA1c range = 6.9-8.2%]. Calf muscle mitochondrial capacity was estimated by (31)P-magnetic resonance spectroscopy. Capillarization and muscle fiber oxidative enzyme activity were assessed from vastus lateralis and soleus muscle biopsies. Oxygen uptake and cardiac output were evaluated by ergospirometry and N(2)O/SF(6) rebreathing. Calf muscle mitochondrial capacity was not different between CON and DIA, as indicated by the identical calculated maximal rates of oxidative ATP synthesis [0.0307 (0.0070) vs. 0.0309 (0.0058) s(-1), P = 0.930]. Notably, HbA1c was negatively correlated with mitochondrial capacity in DIA (R(2) = 0.475, P = 0.040). Although HbA1c was negatively correlated with cardiac output (R(2) = 0.742, P = 0.013) in DIA, there was no difference between CON and DIA in maximal oxygen consumption [2.17 (0.34) vs. 2.21 (0.32) l/min, P = 0.764], cardiac output [12.1 (1.9) vs. 12.3 (1.8) l/min, P = 0.783], and endurance capacity [532 (212) vs. 471 (119) s, P = 0.475]. There was also no difference between the two groups either in the oxidative enzyme activity or capillary-to-fiber ratio. We conclude that mitochondrial capacity depends on HbA1c in untrained women with type 1 diabetes but is not reduced relative to untrained healthy women.

  • 出版日期2011-7