Search

Objectives: This study investigated whether an association between insulin resistance (IR) and muscle parameters is appreciable in young healthy men, independent of obesity. Furthermore, markers of muscle metabolism and hormones/possible determinants, were explored., Methods: 358 healthy young men were divided into a less and more insulin sensitive (LIS [age=33.2±5.4, BMI=23.4±2.3] and MIS [age=35.5±5.3, BMI=28.1±3.7]) group based on upper and lower quartile of HOMA-IR. Muscle cross-sectional area (CSA), -density, handgrip force, serum testosterone, estradiol, SHBG, Vitamin 25(OH)D, creatinine, IGF-1, IGFBP-3 and leptin levels were compared between these groups, correcting for differences in age, physical activity and fat mass. Correlations between HOMA-IR and these parameters, and between muscle measures and biochemical parameters, were calculated., Results: LIS is related to lower relative muscle CSA, muscle density, muscle/fat CSA ratio, relative handgrip force and level of physical activity. Furthermore, lower levels in SHBG, testosterone, Vitamin 25(OH)D and higher leptin, IGF-1 and IGFBP-3 levels were observed in LIS. Bio available T, FT, TE2, FE2, bioavailable E2, serum and urinary creatinine levels did not differ between groups., Conclusion: Differences in muscle performance are already present in healthy men with lower insulin sensitivity and could be possibly modifiable risk factors for the development of type 2 diabetes., Competing Interests: The authors have no conflict of interest.

Objectives: The purpose of this study was to investigate whether there is already an association of insulin resistance (IR) with muscle mass and -force/torque in an adult population and whether this relationship is the same in distal and proximal body parts., Methods: 358 Healthy young men were divided into a more insulin sensitive (MIS) (n=89) and a less insulin sensitive (LIS) group (n=89), respectively using lower and upper quartiles of HOMA-IR index (Homeostasis Model Assessment of IR). Muscle force/torque and lean mass, were compared between the two groups., Results: LIS subjects had higher absolute thigh lean mass, but not higher thigh muscle torque, resulting in a lower torque per kg muscle. In upper arm, lean mass was higher in LIS subjects, but also absolute muscle torque resulted higher. For handgrip force, the LIS and MIS group had similar results, despite a trend towards higher forearm lean mass in LIS subjects. Lean mass % of total lean mass is lower in LIS subjects in more distal body parts., Conclusions: Already in a young healthy population, IR seems to be associated with lower force/torque per muscle mass and lower lean mass % of total lean mass predominantly in more distal body parts.

Objective: In this study we evaluated the effect of sprint interval training on metabolic and physical fitness in adolescents and young adults with intellectual disabilities when compared with continuous aerobic training and no training (control)., Methods: Fifty-four persons with intellectual disabilities (age: 17 (3.0), body mass index: 27.7 (3.7), intelligence quotient: 59 (8.6)) were matched based on age, gender and intelligence quotient between sprint interval training (n = 17), continuous aerobic training (n = 15) and control (n = 14). Sprint interval training was composed of three blocks of 10 minutes at ventilatory threshold (blocks 1 and 3: 10 sprint bouts of 15 seconds, followed by 45 seconds relative rest; block 2: continuous training) twice a week for 15 weeks. Continuous aerobic training was composed of three blocks of 10 minutes continuous training. After eight weeks, intensity was increased to 110% of ventilatory threshold. The control group did not participate in supervised exercise training. Before and after the training period, body composition, physical and metabolic fitness were evaluated., Results: Sprint interval training showed a significant positive evolution for waist circumference, fat%, systolic blood pressure, lipid profile, fasting insulin, homeostasis model assessment of insulin resistance, peak VO2, peak Watt, ventilatory threshold, 6-minute walk distance and muscle fatigue resistance when compared with no training (P < 0.01). The sprint interval training group demonstrated significant improvements for fat%, systolic blood pressure, low-density lipoprotein, fasting insulin, peak VO2 and peak power and ventilatory threshold (P < 0.01) when compared with continuous aerobic training., Conclusion: In this study we could observe that sprint interval training has stronger beneficial effects on body composition, physical fitness and metabolic fitness compared with control. Compared with continuous aerobic training, sprint interval training seems to result in better outcome.

Objective: To investigate the effect of peripheral neuropathy and cognition on gait performance in older adults with type 2 diabetes mellitus., Design: Cross-sectional study., Setting: Community and residential aged care setting., Participants: Older adults (N=101; 56 patients with diabetes, 28 with peripheral neuropathy and 28 without peripheral neuropathy; and 45 matched controls)., Interventions: Not applicable., Main Outcome Measures: Spatiotemporal gait parameters were recorded under 3 conditions: simple, counting backward by 3 from 40, and reciting animal names. The Mini-Mental State Examination and the clock drawing test were used to estimate cognitive impairment levels., Results: Compared with controls, older adults with diabetes walked slower, took shorter strides during all walking conditions, and showed more gait variability especially during dual-task conditions. Gait patterns did not differ between participants suffering from diabetes mellitus with and without neuropathy. Compared with normal walking, dual-task conditions affected all gait parameters similarly in all groups. Backward counting affected gait more than animal naming in participants with diabetes but not in healthy controls. Additional analyses in older adults with diabetes showed that participants with impaired cognitive function walked slower, took shorter strides, had shorter double support time, and increased gait variability compared with participants with intact cognitive function., Conclusions: This study showed that gait parameters are affected in older adults with type 2 diabetes. Gait was further affected by reduced cognitive function, irrespective of the presence of neuropathy., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)