Differences in the acute effects of aerobic and resistance exercise in subjects with type 2 diabetes: results from the RAED2 Randomized Trial.

Elisabetta Bacchi,Maddalena Trombetta,Carlo Negri,Paolo Moghetti,Maria Elisabetta Zanolin,Massimo Lanza,Enzo Bonora,Conrad P. Earnest

doi:10.1371/journal.pone.0049937

Elisabetta Bacchi, Maddalena Trombetta + Show 6 more

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https://doi.org/10.1371/journal.pone.0049937

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Abstract

ObjectiveBoth aerobic (AER) and resistance (RES) training, if maintained over a period of several months, reduce HbA1c levels in type 2 diabetes subjects. However, it is still unknown whether the short-term effects of these types of exercise on blood glucose are similar. Our objective was to assess whether there may be a difference in acute blood glucose changes after a single bout of AER or RES exercise.Study DesignTwenty-five patients participating in the RAED2 Study, a RCT comparing AER and RES training in diabetic subjects, were submitted to continuous glucose monitoring during a 60-min exercise session and over the following 47 h. These measurements were performed after 10.9+0.4 weeks of training. Glucose concentration areas under the curve (AUC) during exercise, the subsequent night, and the 24-h period following exercise, as well as the corresponding periods of the non-exercise day, were assessed. Moreover, the low (LBGI) and high (HBGI) blood glucose indices, which summarize the duration and extent of hypoglycaemia or hyperglycaemia, respectively, were measured.ResultsAER and RES training similarly reduced HbA1c. Forty-eight hour glucose AUC was similar in both groups. However, a comparison of glucose AUC during the 60-min exercise period and the corresponding period of the non-exercise day showed that glucose levels were lower during exercise in the AER but not in the RES group (time-by-group interaction p = 0.04). Similar differences were observed in the nocturnal periods (time-by-group interaction p = 0.02). Accordingly, nocturnal LBGI was higher in the exercise day than in the non-exercise day in the AER (p = 0.012) but not in the RES group (p = 0.62).ConclusionsAlthough AER and RES training have similar long-term metabolic effects in diabetic subjects, the acute effects of single bouts of these exercise types differ, with a potential increase in late-onset hypoglycaemia risk after AER exercise.Trial registrationClinicalTrials.gov NCT01182948

Highlights

Current guidelines for exercise in subjects with type 2 diabetes recommend performing, whenever possible, both aerobic and resistance exercise training [1]
Forty-eight hour glucose areas under the curve (AUC) was similar in both groups
A comparison of glucose AUC during the 60-min exercise period and the corresponding period of the non-exercise day showed that glucose levels were lower during exercise in the AER but not in the RES group

Summary

Results

Subjects of the aerobic and resistance training groups participating in the sub-project had similar baseline characteristics (Table 1). Subsequent analyses of changes within groups showed significantly lower glucose AUC during exercise than in the corresponding period of the nonexercise day in the AER group, but not in the RES group (p = 0.04 and p = 0.90, respectively). Differences between the groups were found in the comparison of glucose AUC measured during the nocturnal period following the training session and the corresponding period of the non-exercise day (time-by-group interaction, p = 0.02, Tab.). Multiple regression analysis was carried out to assess whether there were additional variables independently associated with glucose changes These showed that gender, medication category (insulin sensitizers vs secretagogues), age and baseline glucose levels were not significant predictors of changes in blood glucose, either in the exercise period or in the nocturnal period or in the whole exercise day (data not shown).

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