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This Article Full Text Full Text (PDF) All Versions of this Article: 293/1/E421    most recent 00123.2007v3 00123.2007v2 00123.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by O'Leary, V. B. Articles by Kirwan, J. P. Search for Related Content PubMed PubMed Citation Articles by O'Leary, V. B. Articles by Kirwan, J. P.

Enhanced adiponectin multimer ratio and skeletal muscle adiponectin receptor expression following exercise training and diet in older insulin-resistant adults

¹Department of Pathobiology, Lerner Research Institute; ²Department of Gastroenterology and Hepatology, Cleveland Clinic; ³Department of Physiology, Case Western Reserve University, School of Medicine; ⁴Department of Medicine, MetroHealth Medical Center, Cleveland, Ohio; ⁵Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, Minnesota; ⁶Division of Pediatric Endocrinology, School of Medicine, University of California San Diego; and ⁷Division of Diabetes, Endocrinology and Metabolism, Veterans Affairs San Diego Health Care System, San Diego, California

Submitted 23 February 2007 ; accepted in final form 8 May 2007

Circulating adiponectin is reduced in disorders associated with insulin resistance. This study was conducted to determine whether an exercise/diet intervention would alter adiponectin multimer distribution and adiponectin receptor expression in skeletal muscle. Impaired glucose-tolerant older (>60 yr) obese (BMI 30–40 kg/m²) men (n = 7) and women (n = 14) were randomly assigned to 12 wk of supervised aerobic exercise combined with either a hypocaloric (ExHypo, 500 kcal reduction, n = 11) or eucaloric diet (ExEu, n = 10). Insulin sensitivity was determined by the euglycemic (5.0 mM) hyperinsulinemic (40 mU·m^–2·min^–1) clamp. Adiponectin multimers [high (HMW), middle (MMW), and low molecular weight (LMW)] were measured by nondenaturing Western blot analysis. Relative quantification of adiponectin receptor expression through RT-PCR was determined from skeletal muscle biopsy samples. Greater weight loss occurred in ExHypo compared with ExEu subjects (8.0 ± 0.6 vs. 3.2 ± 0.6%, P < 0.0001). Insulin sensitivity improved postintervention in both groups (ExHypo: 2.5 ± 0.3 vs. 4.4 ± 0.5 mg·kg FFM^–1·min^–1, and ExEu: 2.9 ± 0.4 vs. 4.1 ± 0.4 mg·kg FFM^–1·min^–1, P < 0.0001). Comparison of multimer isoforms revealed a decreased percentage in MMW relative to HMW and LMW (P < 0.03). The adiponectin SA ratio (HMW/total) was increased following both interventions (P < 0.05) and correlated with the percent change in insulin sensitivity (P < 0.03). Postintervention adiponectin receptor mRNA expression was also significantly increased (AdipoR1 P < 0.03, AdipoR2 P < 0.02). These data suggest that part of the improvement in insulin sensitivity following exercise and diet may be due to changes in the adiponectin oligomeric distribution and enhanced membrane receptor expression.

glucose intolerance; diabetes; obesity; aging; gene expression

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				T. P. J. Solomon, S. N. Sistrun, R. K. Krishnan, L. F. Del Aguila, C. M. Marchetti, S. M. O'Carroll, V. B. O'Leary, and J. P. Kirwan Exercise and diet enhance fat oxidation and reduce insulin resistance in older obese adults J Appl Physiol, May 1, 2008; 104(5): 1313 - 1319. [Abstract] [Full Text] [PDF]