Strength training improves muscle quality and insulin sensitivity in Hispanic older adults with type 2 diabetes

Abstract

Hispanics are at increased risk of morbidity and mortality due to their high prevalence of diabetes and poor glycemic control. Strength training is the most effective lifestyle intervention to increase muscle mass but limited data is available in older adults with diabetes. We determined the influence of strength training on muscle quality (strength per unit of muscle mass), skeletal muscle fiber hypertrophy, and metabolic control including insulin resistance (Homeostasis Model Assessment –HOMA-IR), C-Reactive Protein (CRP), adiponectin and Free Fatty Acid (FFA) levels in Hispanic older adults. Sixty-two community-dwelling Hispanics (>55 y) with type 2 diabetes were randomized to 16 weeks of strength training plus standard care (ST group) or standard care alone (CON group). Skeletal muscle biopsies and biochemical measures were taken at baseline and 16 weeks. The ST group show improved muscle quality (mean±SE: 28±3) vs CON (-4±2, p<0.001) and increased type I (860±252µm2) and type II fiber cross-sectional area (720±285µm2) compared to CON (type I: -164±290µm2, p=0.04; and type II: -130±336µm2, p=0.04). This was accompanied by reduced insulin resistance [ST: median (interquartile range) -0.7(3.6) vs CON: 0.8(3.8), p=0.05]; FFA (ST: -84±30µmol/L vs CON: 149±48µmol/L, p=0.02); and CRP [ST: -1.3(2.9)mg/L vs CON: 0.4(2.3)mg/L, p=0.05]. Serum adiponectin increased with ST [1.0(1.8)µg/mL] compared to CON [-1.2(2.2)µg/mL, p<0.001]. Strength training improved muscle quality and whole-body insulin sensitivity. Decreased inflammation and increased adiponectin levels were related with improved metabolic control. Further studies are needed to understand the mechanisms associated with these findings. However, these data show that strength training is an exercise modality to consider as an adjunct of standard of care in high risk populations with type 2 diabetes.

Exercise interventions in polypathological aging patients that coexist with diabetes mellitus: improving functional status and quality of life

“…Similar results were observed by Brooks et al (2007), who observed a reduction of 1.2 % in the HbA1c levels (P < 0.05) after 16 weeks of resistance training performed three times per week consisting of three sets of eight repetitions at an intensity ranging from 60 to 80 % of 1 RM. In all of these studies, no significant alteration in glycemic control was observed in the control group that did not perform any exercise intervention.…”

“…In addition to its important effect on glycemic control, resistance training is a very important intervention because it counteracts the exacerbated loss of muscle strength and functional capacity observed in elderly patients (Castaneda et al 2002;Dunstan et al 2002;Brooks et al 2007;Ibañez et al 2008;Geirsdottir et al 2012). For example, in study of Brandon et al (2003), 24 weeks of resistance training performed at moderate intensity induced increases in muscle strength and mobility in elderly with type 2 diabetes.…”

“…For example, in study of Brandon et al (2003), 24 weeks of resistance training performed at moderate intensity induced increases in muscle strength and mobility in elderly with type 2 diabetes. In general, studies have demonstrated that applying a resistance training intervention consisting of either two or three sets of 8-15 repetitions at an intensity ranging from 50 to 85 % of one maximum repetition (1 RM) performed two or three times per week for between 8 and 24 weeks markedly increases maximal muscle strength in elderly type 2 diabetic patients (Castaneda et al 2002;Dunstan et al 2002;Brooks et al 2007;Ibañez et al 2008;Geirsdottir et al 2012). It should be mentioned that lower resistance training volume (i.e., one set per exercise) may induce similar neuromuscular improvements as higher volumes (i.e., two to three sets per exercise) in healthy elderly subjects, especially in early phases of training (i.e., 3 months) (Radaelli et al 2014).…”

Beneficial Health Effect of Aquarobics (Role of Adiponectin on Women with Obesity)

“…Moreover, a significant difference was observed in the plasma level of adiponectin in the experimental group between the pre-test and post-test stages. The increase in the plasma level of adiponectin as a result of 12 weeks of aquarobics exercises was most likely a preventive factor for diseases related to adiponectin (32,36). In this research, the increase in the level of adiponectin after adjusting to the aquarobics exercises was similar to the results of a number of previous studies.…”

Effect of exercise training on neuromuscular function of elbow flexors and knee extensors of type 2 diabetic patients

“…Resistance training in particular has been seen to improve both muscle strength and 20 mass as well as insulin sensitivity (Brooks et al, 2007;Cauza et al, 2005;Dunstan et 21 al., 2002;Holten et al, 2004;LeBrasseur et al, 2011;Mann et al, 2014). For these 22 reasons, it may be desirable that type 2 diabetes patients would begin an appropriate 23 exercise training program as soon as possible after diagnosis to prevent, or at least 24 limit, the decline in neuromuscular function.…”