Endocrinology and Metabolism

Altered energetic properties in skeletal muscle of men with well-controlled insulin-dependent (type 1) diabetes

Gregory J. Crowther, Jerrold M. Milstein, Sharon A. Jubrias, Martin J. Kushmerick, Rodney K. Gronka, Kevin E. Conley


This study asked whether the energetic properties of muscles are changed by insulin-dependent diabetes mellitus (or type 1 diabetes), as occurs in obesity and type 2 diabetes. We used 31P magnetic resonance spectroscopy to measure glycolytic flux, oxidative flux, and contractile cost in the ankle dorsiflexor muscles of 10 men with well-managed type 1 diabetes and 10 age- and activity-matched control subjects. Each subject performed sustained isometric muscle contractions lasting 30 and 120 s while attempting to maintain 70–75% of maximal voluntary contraction force. An altered glycolytic flux in type 1 diabetic subjects relative to control subjects was apparent from significant differences in pH in muscle at rest and at the end of the 120-s bout. Glycolytic flux during exercise began earlier and reached a higher peak rate in diabetic patients than in control subjects. A reduced oxidative capacity in the diabetic patients' muscles was evident from a significantly slower phosphocreatine recovery from a 30-s exercise bout. Our findings represent the first characterization of the energetic properties of muscle from type 1 diabetic patients. The observed changes in glycolytic and oxidative fluxes suggest a diabetes-induced shift in the metabolic profile of muscle, consistent with studies of obesity and type 2 diabetes that point to common muscle adaptations in these diseases.

  • glycolysis
  • mitochondrial oxidative phosphorylation
  • tibialis anterior muscle


  • This research was supported by National Institute of Arthritis and Musculoskeletal and Skin Diseases Grants AR-41928 and AR-45184 and by the Diabetes Endocrinology Research Center Grant no. 5-P30-DK-17047. G. J. Crowther was supported in part by a National Science Foundation predoctoral fellowship.

  • Address for reprint requests and other correspondence: K. E. Conley, Dept. of Radiology, Box 357115, Univ. of Washington Medical Center, Seattle, WA 98195-7115 (E-mail:kconley{at}u.washington.edu).

  • The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

  • 10.1152/ajpendo.00343.2002

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