Aerobic plus resistance training was more effective than either alone in type 2 diabetes.

ED FROM Sigal RJ, Kenny GP, Boule NG, et al. Effects of aerobic training, resistance training, or both on glycemic control in type 2 diabetes: a randomized trial. Ann Intern Med 2007;147:357–69. Correspondence to: Dr R J Sigal, University of Calgary, Calgary, Alberta, Canada; [email protected] Source of funding: Canadian Institutes of Health Research and Canadian Diabetes Association. c Clinical impact ratings: GP/FP Primary care 6/7; IM/Ambulatory care 5/7; Endocrine 5/7; Physical medicine & rehabilitation 5/7 Comparisons of aerobic training, resistance training, combined training, and no exercise for type 2 diabetes* Outcomes at 6 months Mean change from baseline Difference in change between groups (95% CI) Combined Aerobic Resistance No exercise HbA1c concentration (%) — 20.43 — 0.07 20.51 (20.87 to 20.14) — — 20.30 0.07 20.38 (20.72 to 20.22) 20.90 20.43 — — 20.46 (20.83 to 20.09) 20.90 — 20.30 — 20.59 (20.95 to 20.23) Body weight (kg) — 22.6 — 20.3 22.2 (23.9 to 20.6) Waist circumference (cm) — 23.0 — 21.0 22.1 (24.1 to 20.2) *Hb = haemoglobin; CI defined in glossary. Analysis based on a mixed-effects model and adjusted for age, sex, training site, and hypoglycaemic medication. C O M M EN TA R Y O ptimal management of type 2 diabetes includes exercise. The American Diabetes Association recommends 150 min/week of aerobic and resistance exercise. However, this recommendation does not address the issue of the incremental effect of combined aerobic and resistance exercises. This well-designed study by Sigal et al is an important contribution to the knowledge base on the incremental effects of combined aerobic and resistance exercise for glycaemic control in type 2 diabetes. It overcame some of the challenges faced by behaviour modification studies; however, participants were motivated volunteers who were given the incentive of a free gym membership, which is difficult to achieve in routine practice. Of note, the combined group exercised twice as much as the aerobic or resistance training groups alone; thus, it is difficult to know whether the difference in HbA1c change between the groups is because of the duration or the combination of exercise. The incremental effect of combined exercise on body composition, lipids, and BP was not significant; however, aerobic exercise reduced waist circumference more than no exercise. Clinicians can be more confident about giving specific advice about exercise, especially on the incremental effect of aerobic and resistance training on improving glycaemic control. The study also allows for estimation of the effect of exercise on glycaemic control and shows that this effect is greater in persons with higher HbA1c concentrations. Kamlesh Bhargava, MD, MRCGP(INT) Sultan Qaboos University, Muscat, Oman 1. Sigal RJ, Kenny GP, White RR, et al. Diabetes Care 2006;29:1433–38. Therapeutics 40 EBM April 2008 Vol 13 No 2 group.bmj.com on September 19, 2017 Published by http://ebm.bmj.com/ Downloaded from