Obesity blunts insulin-mediated microvascular recruitment in human forearm muscle

Lucy H. Clerk, Michelle A. Vincent, Linda A. Jahn, Zhenqi Liu, Jonathan R. Lindner, Eugene J. Barrett

    Research output: Contribution to journalArticle

    200 Scopus citations

    Abstract

    We have previously shown that skeletal muscle capillaries are rapidly recruited by physiological doses of insulin in both humans and animals. This facilitates glucose and insulin delivery to muscle, thus augmenting glucose uptake. In obese rats, both insulin-mediated microvascular recruitment and glucose uptake are diminished; however, this action of insulin has not been studied in obese humans. Here we used contrast ultrasound to measure microvascular blood volume (MBV) (an index of microvascular recruitment) in the forearm flexor muscles of lean and obese adults before and after a 120-min euglycemic-hyperinsulinemic (1 mU·min-1·kg -1) clamp. We also measured brachial artery flow, fasting lipid profile, and anthropomorphic variables. Fasting plasma glucose (5.4 ± 0.1 vs. 5.1 ± 0.1 mmol/l, P = 0.05), insulin (79 ± 11 vs. 38 ± 6 pmol/l, P = 0.003), and percent body fat (44 ± 2 vs. 25 ± 2%, P = 0.001) were higher in the obese than the lean adults. After 2 h of insulin infusion, whole-body glucose infusion rate was significantly lower in the obese versus lean group (19.3 ± 3.2 and 37.4 ± 2.6 μmol· min-1·kg-1 respectively, P < 0.001). Compared with baseline, insulin increased MBV in the lean (18.7 ± 3.3 to 25.0 ± 4.1, P = 0.019) but not in the obese group (20.4 ± 3.6 to 18.8 ± 3.8, NS). Insulin increased brachial artery diameter and flow in the lean but not in the obese group. We observed a significant, negative correlation between MBV and ΔBMI (R = -0.482, P = 0.027) in response to insulin. In conclusion, obesity eliminated the insulin-stimulated muscle microvascular recruitment and increased brachial artery blood flow seen in lean individuals.

    Original languageEnglish (US)
    Pages (from-to)1436-1442
    Number of pages7
    JournalDiabetes
    Volume55
    Issue number5
    DOIs
    StatePublished - Aug 15 2006

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    Keywords

    • MBV
    • MFV, microvascular flow velocity
    • Microvascular blood volume

    ASJC Scopus subject areas

    • Internal Medicine
    • Endocrinology, Diabetes and Metabolism

    Cite this

    Clerk, L. H., Vincent, M. A., Jahn, L. A., Liu, Z., Lindner, J. R., & Barrett, E. J. (2006). Obesity blunts insulin-mediated microvascular recruitment in human forearm muscle. Diabetes, 55(5), 1436-1442. https://doi.org/10.2337/db05-1373