Insulin sensitivity in response to resistance training in those at risk for Type II Diabetes Mellitus

2010 Asics Conference of Science and Medicine in Sport / Journal of Science and Medicine in Sport 13S (2010) e1–e107

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Bone remodeling and type 2 diabetes: Effects of acute exercise

Insulin sensitivity in response to resistance training in those at risk for Type II Diabetes Mellitus

I. Levinger 1,∗ , R. Zebaze 2 , G. Jerums 2 , D. Hare 3 , S. Selig 1 , E. Seeman 2

K. Schofield 1,∗ , N. Rehrer 1 , A. Ross 2 , T. Perry 3

1 Institute

for Sport, Exercise and Active Living, School of Sport and Exercise Science, Victoria University, Australia 2 The University of Melbourne and the Department of Endocrinology, Austin Health, Australia 3 The University of Melbourne and the Department of Cardiology, Austin Health, Australia Background: Bone via osteocalcin (OC) in its undercarboxylated (unOC) form may contribute to glucose homeostasis. Exercise improves insulin sensitivity. We examined whether acute aerobic and power exercise mediate the beneficial effects on glycaemic control through unOC in individuals with type 2 diabetes (T2DM). Methods: Men and women aged 52.5 ± 1.0 (mean ± SEM) with (n = 23) and without T2DM (n = 26) were randomised to 45 min of aerobic (cycling at 75% of VO2 peak) or power (leg press at 75% of 1RM plus jumping sequence) exercises. Blood samples were taken at baseline and up to 2 h post-exercise. Results: Diabetics had lower OC (3.2 ± 0.3 versus 5.7 ± 0.4 ng mL−1 , p < 0.001), unOC (4.0 ± 0.4 versus 5.2 ± 0.4 ng mL−1 , p = 0.004) and high-molecular-weight adiponectin (HMW-AN, 1.7 ± 0.3 versus 2.6 ± 0.44 ng mL−1 , p = 0.061) compared to nondiabetics. In diabetics, aerobic and power exercise reduced serum glucose (p < 0.05). Aerobic exercise increased unOC (7.1 ± 2.6%, p = 0.029) and unOC/OC ratio (28.2 ± 9.9%, p = 0.022) whilst power exercise improved the unOC/OC ratio (16 ± 4.4%, p = 0.003). Changes in glucose levels correlated inversely with changes in unOC (r = −0.45, p = 0.021). Neither form of exercise altered HMW-AN. Similar results were observed in non-diabetics, but HMW-AN increased with both forms of exercise and changes in HMW-AN correlated inversely with glucose (r = −0.52, p = 0.005). For the whole cohort, those with higher baseline glucose levels had a greater reductions in glucose after exercise (r = −0.30, p = 0.02). LBM and muscle strength correlated inversely with the change of unOC (r = −0.34, p = 0.049, r = −0.27, p = 0.032, respectively). Conclusions: Acute aerobic and power exercise increased serum unOC, associated with lower serum glucose after exercise in diabetics. Those with low muscle mass and muscle strength and those with higher glucose exhibited larger increase in unOC and reduction in glucose levels. Benefits of exercise on glucose metabolism may be explained partly by effects on a bone derived protein. doi:10.1016/j.jsams.2010.10.587

1 School of Physical Education, University of Otago, New Zealand 2 NZ Academy of Sport, South Island, New Zealand 3 Department of Human Nutrition, University of Otago, New Zealand

Introduction: Insulin sensitivity increases with endurance training, however, studies observing insulin sensitivity with resistance training is limited, and with detraining studies moreso. This study examined insulin sensitivity and strength in offspring of Type II diabetics after resistance training and detraining. Method: Six (1 male, 5 female; 21.3 ± 1.8 years, 164.7 ± 4.6 cm, 62.2 ± 7.1 kg, mean ± SD) familial insulin resistant (FR) and 10 (4 male, 6 female; 23.0 ± 2.9 years, 169.7 ± 10.6 cm, 69.3 ± 14.1 kg, mean ± SD) controls (C) completed 9 weeks of resistance training: squat (SQ), leg press (LP), leg extension (LE), leg curl (LC) and box jump, followed by 9 weeks detraining. Measures at baseline (T1), after training (T2) and after detraining (T3) included an oral glucose tolerance test and performance tests (3RM; vertical jump). Repeated measures ANOVA were conducted. Results: There was a significant change in SQ, LP, LE and LC 3RM over time (P < 0.05). From T1 to T2, increases of 78 ± 28, 67 ± 40, 103 ± 46 and 69 ± 28%, resp., were observed in men, and 81 ± 27, 47 ± 25, 109 ± 46 and 65 ± 33%, resp., in women. 3RM decreased from T2 to T3 in men (−11 ± 7, −8 ± 5, −15 ± 5, −12 ± 7%, resp.) and women (−8 ± 6, −5 ± 6, −16 ± 4, −11 ± 8%, resp.). Fasting glucose did not change over time in FR (4.7 ± 0.5, 4.7 ± 0.2, 4.7 ± 0.2 mmol/L, T1, T2, T3, resp.) nor in C (5.1 ± 0.2, 4.9 ± 0.4, 4.8 ± 0.2 mmol/L, resp.), and was similar in both. Fasting insulin did not change over time in FR (8.8 ± 3.8, 8.2 ± 3.4, 8.5 ± 4.0 ␮U/ml, resp.) or C (7.4 ± 3.7, 6.4 ± 2.9, 6.3 ± 2.1 ␮U/ml, resp.), with no significant difference between FR and C. Insulin area under the curve (AUC) did, however, differ (P = 0.02) across time (T1, T2, T3) and between FR and C (P = 0.03). There was a significant interaction (P = 0.02), with a greater decrease in Insulin AUC in FR than in C with training and an increase in Insulin AUC in FR, but not in C, with detraining. Conclusions: Resistance training for 9 weeks produces similar increases in strength in both FR and C, and decreases in strength with detraining. Responses to a glucose load, however, are different. Those with familial insulin resistance exhibit a greater training effect of reducing insulin AUC and, in contrast to controls, an increase with detraining. While this population did not show clinical signs for diabetes, resistance training can increase insulin

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2010 Asics Conference of Science and Medicine in Sport / Journal of Science and Medicine in Sport 13S (2010) e1–e107

sensitivity and may reduce future risk of Type II diabetes.

the study may have lead to some placebo-induced improvements in control subjects, but not to the same extent as those involved in exercise programs.

doi:10.1016/j.jsams.2010.10.588 doi:10.1016/j.jsams.2010.10.589 128 129 Efficacy of an exercise program on the functional capacity and disease activity in females with rheumatoid arthritis C. Janse Van Rensburg ∗ , L. Fletcher, M. Viljoen, C. Coertzen, R. Grant, M. Ramagole, R. Collins, J. Ker University of Pretoria, South Africa Background: Rheumatoid arthritis (RA) is a chronic, immune-inflammatory disease of unknown aetiology affecting the synovial membrane of joints and surrounding tissues. Typically RA affects both large and small joints in a bilateral, symmetrical, poly-articular fashion. Degradation of bone, cartilage and muscle eventually lead to a reduction in physical function. The purpose of this study was to determine the efficacy of an endurance exercise program on the fitness parameters (flexibility, strength, and aerobic measurements), quality of life (visual analogue scale and health assessment questionnaire) and disease activity (DAS 28(4) version with CRP) of female RA patients. Methods: Female RA patients were randomly allocated to the experimental group (EG) (n = 19) and the control group (CG) (n = 8). All participants went through a battery of tests before the intervention, and again after completion of the study. The 12-week training program consisted of three, 45 min training sessions per week and included walking or aquatics, as well as stretches and isotonic strengthening exercises. The Mann–Whitney U test was used to compare measurements between groups. The Wilcoxon signed-rank test was used to compare baseline and post-intervention measurements within each group. Results: At the initiation of the study the CG and the EG were comparable for fitness, quality of life and disease activity. At completion of the training program statistically significant improvements at the 5% level of significance were seen between the EG and CG, in favour of the EG, for left lateral flexion (p = 0.015) and the 1 mile walk test (p = 0.011). Within the EG there were improvement of knee flexion left (p = 0.026), knee extension (right p = 0.011; left p = 0.009), scratch test (right p = 0.007; left p = 0.01), chair sit and reach (right p = 0.011, left p < 0.001), strength parameters (p < 0.05), 1 mile walk test (p < 0.001), VO2 max (p = 0.01) and DAS scores (p < 0.001). Within the CG improvements were shown for knee extension (right p = 0.05; left p = 0.013). Although their strength parameters improved significantly it was not in the same order as for the EG. The CG had a decline in their aerobic measurements, but their HAQ score improved (p = 0.03). Conclusion: An endurance exercise program combined with isotonic strengthening exercise and stretching improves the functional capacity, quality of life and disease activity of female patients with RA. Attention received during

The effects of a supplemental, theory-based physical activity counselling intervention for adults with type 2 diabetes R. Plotnikoff 1,∗ , M. Pickering 2 , N. Glenn 2 , S. Doze 4 , M. Reinbold-Matthews 2 , L. McLeod 4 , D. Lau 3 , G. Fick 3 , S. Johnson 2 , L. Flaman 2 1 The

University of Newcastle, Australia of Alberta, Canada 3 University of Calgary, Canada 4 David Thompson Health Region, Canada 2 University

Introduction: Among individuals with type 2 diabetes mellitus (T2DM), participation in regular physical activity (PA) has been linked to improvements in cardiovascular risk profile, increased cardiorespiratory fitness, and an overall improved quality-of-life. In spite of these benefits however, current prevalence estimates of PA indicate the majority of adults with T2DM remain either sedentary or insufficiently active to achieve health benefits. This study explored the effects of a standard diabetes education program compared to a supplemental PA intervention on diabetes-related health outcomes. Methodology: Adults aged 25–78 years with physician confirmed diagnosis of T2DM were recruited from voluntary-enrollment diabetes education programs, in Red Deer, Alberta, Canada. Using a prospective two-armed design, individuals who completed baseline assessment (n = 96) were randomly assigned to either standard care (DEP group; diabetes education program; n = 49) or standard care supplemented with an 8-week, individualized-counseling and community-based physical activity component (DEPplusPAS group; n = 47). Measurements were taken at baseline, 3, 6 and 12-months. Primary outcomes were changes in PA and HbA1c. A number of secondary outcomes were also assessed. Between group changes were compared using analysis of covariance (ANCOVA) (adjusting for baseline scores) and group changes over time using repeated-measures ANOVA. Results: Compared to baseline values, participants in the DEP group reported non-significant increases in mean weekly METmins of 125.9 and 95.0 at 3- and 6-months, respectively, and a decrease of 33.9 METmins, at 12-months. The DEPplusPAS group reported significant increases of 601.6, 549.1, and 654.2 METmins (p < 0.01) across the three respective time points. The differences in PA behavior change scores between groups were significantly larger for the DEPplusPAS group at all three time points (p < 0.01). HbA1c levels declined (p < 0.05) from baseline to all time points in the standard care group. Cardiorespiratory fitness improved for