Effect of an Intensive Lifestyle Intervention on Glycemic Control in Patients With Type 2 Diabetes: A Randomized Clinical Trial

Abstract

Importance: It is unclear whether a lifestyle intervention can maintain glycemic control in patients with type 2 diabetes.

Objective: To test whether an intensive lifestyle intervention results in equivalent glycemic control compared with standard care and, secondarily, leads to a reduction in glucose-lowering medication in participants with type 2 diabetes.

Design, setting, and participants: Randomized, assessor-blinded, single-center study within Region Zealand and the Capital Region of Denmark (April 2015-August 2016). Ninety-eight adult participants with non-insulin-dependent type 2 diabetes who were diagnosed for less than 10 years were included. Participants were randomly assigned (2:1; stratified by sex) to the lifestyle group (n = 64) or the standard care group (n = 34).

Interventions: All participants received standard care with individual counseling and standardized, blinded, target-driven medical therapy. Additionally, the lifestyle intervention included 5 to 6 weekly aerobic training sessions (duration 30-60 minutes), of which 2 to 3 sessions were combined with resistance training. The lifestyle participants received dietary plans aiming for a body mass index of 25 or less. Participants were followed up for 12 months.

Main outcomes and measures: Primary outcome was change in hemoglobin A1c (HbA1c) from baseline to 12-month follow-up, and equivalence was prespecified by a CI margin of ±0.4% based on the intention-to-treat population. Superiority analysis was performed on the secondary outcome reductions in glucose-lowering medication.

Results: Among 98 randomized participants (mean age, 54.6 years [SD, 8.9]; women, 47 [48%]; mean baseline HbA1c, 6.7%), 93 participants completed the trial. From baseline to 12-month follow-up, the mean HbA1c level changed from 6.65% to 6.34% in the lifestyle group and from 6.74% to 6.66% in the standard care group (mean between-group difference in change of -0.26% [95% CI, -0.52% to -0.01%]), not meeting the criteria for equivalence (P = .15). Reduction in glucose-lowering medications occurred in 47 participants (73.5%) in the lifestyle group and 9 participants (26.4%) in the standard care group (difference, 47.1 percentage points [95% CI, 28.6-65.3]). There were 32 adverse events (most commonly musculoskeletal pain or discomfort and mild hypoglycemia) in the lifestyle group and 5 in the standard care group.

Conclusions and relevance: Among adults with type 2 diabetes diagnosed for less than 10 years, a lifestyle intervention compared with standard care resulted in a change in glycemic control that did not reach the criterion for equivalence, but was in a direction consistent with benefit. Further research is needed to assess superiority, as well as generalizability and durability of findings.

Trial registration: clinicaltrials.gov Identifier: NCT02417012.

Conflict of interest statement

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Allan Vaag was appointed vice president for AstraZeneca’s Translational Research and Early Clinical Development during the completion of the study, but remained in the scientific steering committee of this study. Dr Christensen’s employer, the Parker Institute, Bispebjerg, and Frederiksberg Hospital, is supported by core grant OCAY-13-309 from the Oak Foundatian; he reports receiving personal fees from Abbott, AbbVie, Amgen, Axellus A/S, Bayer HealthCare Pharmaceuticals, Biogen Idec, Bristol-Myers Squibb, Cambridge Weight Plan, Celgene, Eli Lilly, Hospira, Ipsen, Janssen, Laboratories Expanscience, Merck Sharp & Dohme, Mundipharma, Norpharma, Novartis, Orkla Health, Pfizer, Roche, Rottapharm-Madaus, Sobi, Takeda, and Wyeth; personal fees from employment from Research Unit for Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics, and the University of Southern Denmark; grants pending and grant funding from Axellus A/S, AbbVie, Cambridge Weight Plan, Janssen, Merck Sharp & Dohme, Mundipharma, Novartis, and Roche; and being involved in many health care initiatives and research that could benefit from wide uptake of this publication including Cochrane, Outcome Measures in Rheumatology, International Dermatology Outcome Measures, RADS, and the Grading of Recommendations Assessment, Development and Evaluation Working Group. No other disclosures were reported.

Figures

Figure 1.. Flow of Participants Through the Study

BMI indicates body mass index (calculated as weight in kilograms divided by height in meters squared).

Figure 2.. Hemoglobin A1c Levels for the Lifestyle vs Standard Care Groups Among Participants With Non–Insulin-Dependent Type 2 Diabetes, Intention-to-Treat Analysis

Data are least squares means derived from mixed linear models and adjusted for baseline hemoglobin A1c and sex. Error bars indicate 95% CIs.

Figure 3.. Proportion of Participants With Non–Insulin-Dependent Type 2 Diabetes With a Reduction in Glucose-Lowering Medication From Baseline in the Lifestyle vs Standard Care Groups

Error bars indicate 95% CIs. If the prespecified treatment target was reached at the medical consultation, the pharmacological treatment was halved. If unchanged values or an additional reduction was observed at the following medical consultation, the medical treatment was paused.