Effect of High- versus Low-Intensity Supervised Aerobic and Resistance Training on Modifiable Cardiovascular Risk Factors in Type 2 Diabetes; The Italian Diabetes and Exercise Study (IDES)

Abstract

BackgroundWhile current recommendations on exercise type and volume have strong experimental bases, there is no clear evidence from large-sized studies indicating whether increasing training intensity provides additional benefits to subjects with type 2 diabetes.ObjectiveTo compare the effects of moderate-to-high intensity (HI) versus low-to-moderate intensity (LI) training of equal energy cost, i.e. exercise volume, on modifiable cardiovascular risk factors.DesignPre-specified sub-analysis of the Italian Diabetes and Exercise Study (IDES), a randomized multicenter prospective trial comparing a supervised exercise intervention with standard care for 12 months (2005–2006).SettingTwenty-two outpatient diabetes clinics across Italy.PatientsSedentary patients with type 2 diabetes assigned to twice-a-week supervised progressive aerobic and resistance training plus exercise counseling (n = 303).InterventionsSubjects were randomized by center to LI (n = 142, 136 completed) or HI (n = 161, 152 completed) progressive aerobic and resistance training, i.e. at 55% or 70% of predicted maximal oxygen consumption and at 60% or 80% of predicted 1-Repetition Maximum, respectively, of equal volume.Main Outcome Measure(s)Hemoglobin (Hb) A1c and other cardiovascular risk factors; 10-year coronary heart disease (CHD) risk scores.ResultsVolume of physical activity, both supervised and non-supervised, was similar in LI and HI participants. Compared with LI training, HI training produced only clinically marginal, though statistically significant, improvements in HbA1c (mean difference −0.17% [95% confidence interval −0.44,0.10], P = 0.03), triglycerides (−0.12 mmol/l [−0.34,0.10], P = 0.02) and total cholesterol (−0.24 mmol/l [−0.46, −0.01], P = 0.04), but not in other risk factors and CHD risk scores. However, intensity was not an independent predictor of reduction of any of these parameters. Adverse event rate was similar in HI and LI subjects.ConclusionsData from the large IDES cohort indicate that, in low-fitness individuals such as sedentary subjects with type 2 diabetes, increasing exercise intensity is not harmful, but does not provide additional benefits on cardiovascular risk factors.Trial Registration www.ISRCTN.org ISRCTN-04252749.

Resistance and Aerobic Training in the Treatment of Type 2 Diabetes Mellitus

“…Based on these data, authors concluded that the HI training is effective in improving the functional capacity and the endothelium-dependent vasodilator response in obese patients with DM2, being an important preventive strategy. Similar result was observed in the Italian Diabetes and Exercise Study, 303 patients (HI and LW intensities groups) improved exercise capacity (VO 2MAX ), insulin sensitivity (HOMA-IR), glycemic control (HbA1C), lipid profile (HDL-c) and strength (1RM), besides reducing systolic and diastolic blood pressure and becoming more physical active after 12 months of treatment [10]. Among the aforementioned variables, the HI and LW groups differed only in muscle strength, HbA1C, and total cholesterol in favor of the HI group.…”

“…It is important to highlight the concomitant performance of strength training (60% 1RM) with endurance protocols, which may have influenced the outcome of the research. These studies show that both training intensities are beneficial in DM2 treatment [8,10].…”

Respuestas metabólicas inducidas por ejercicio físico de alta intensidad en mujeres sedentarias con glicemia basal alterada e hipercolesterolemia

“…Estos resultados concuerdan con estudios previos donde una intervención con EF de alta intensidad redujo los niveles de IMC y PC en -3,8% y -4,9, respectivamente 17 .…”

“…La magnitud de estos cambios fue de -28% y -26,9% en CT, -24% y -18% en C-LDL, +13% y +10% en C-HDL, -20% y -18% en TG en los grupos HH y NH, respectivamente. Estos cambios son superiores a los reportados en estudios previos por Balducci y col., 17 (-12% glicemia, -11% CT, -20% C-LDL, +6,5% C-HDL y -2,6% TG). No obstante, esta diferencia en los cambios podría estar explicada por las características de los participantes, ya que la intervención de Balducci y col. 17 fue aplicada en personas sin alteraciones metabólicas.…”

“…Estos cambios son superiores a los reportados en estudios previos por Balducci y col., 17 (-12% glicemia, -11% CT, -20% C-LDL, +6,5% C-HDL y -2,6% TG). No obstante, esta diferencia en los cambios podría estar explicada por las características de los participantes, ya que la intervención de Balducci y col. 17 fue aplicada en personas sin alteraciones metabólicas. Como ya se ha reportado anteriormente 20,21 , y como también lo demuestran nuestros resultados, los grupos con mejor respuesta al EF son aquellos que presentan una mayor alteración en sus parámetros metabó-licos al inicio del programa de EF, sugiriendo que mientras menor es la condición física y mayor el riesgo metabólico, los beneficios alcanzados mediante el EF serán más significativos.…”