Abnormal Skeletal Muscle Capillary Recruitment During Exercise in Patients With Type 2 Diabetes Mellitus and Microvascular Complications

Lisa Womack, Dawn Peters, Eugene J. Barrett, Sanjiv Kaul, Wendie Price, Jonathan R. Lindner

Research output: Contribution to journalArticle

79 Scopus citations

Abstract

Objectives: We sought to determine whether skeletal muscle capillary recruitment is impaired in type 2 diabetes mellitus (DM) with and without microvascular complications (MC). Background: Insulin and exercise each stimulate recruitment of skeletal muscle capillaries. Insulin-mediated recruitment is impaired in insulin-resistant humans and animals, but exercise-mediated recruitment has not been studied. Methods: We studied 20 control subjects, 22 patients with DM, and 8 patients with DM + MC. With the patients under fasting conditions, contrast-enhanced ultrasound perfusion imaging of the forearm flexor muscles was performed to evaluate capillary blood flow and blood volume at rest and during low- or high-intensity contractile exercise (25% and 80% maximal handgrip). Rheologic parameters of erythrocyte deformability and plasma viscosity were measured. Results: Muscle capillary responses to exercise were similar between the control and DM groups, but were reduced (p < 0.05) in those with DM + MC. The DM + MC group had a ≈50% reduction in capillary recruitment and a ≈60% to 70% reduction in capillary blood flow during both low- and high-intensity exercise compared with the control group. These abnormalities were independent of disease duration. Patients with DM + MC were more insulin resistant than DM patients and had an elevated whole blood viscosity that correlated with plasma glucose (p = 0.001) and C-reactive protein (p = 0.003). Conclusions: Capillary recruitment during low- and high-intensity exercise is normal in uncomplicated type 2 DM but is impaired in those with microvascular complications. Abnormalities in capillary recruitment may be related to abnormal hemorheology, although larger trials are needed to establish this relation.

Original languageEnglish (US)
Pages (from-to)2175-2183
Number of pages9
JournalJournal of the American College of Cardiology
Volume53
Issue number23
DOIs
StatePublished - Jun 9 2009

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Keywords

  • contrast ultrasound
  • diabetes mellitus
  • microbubbles
  • microvascular dysfunction
  • muscle perfusion

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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