Education-based, lifestyle intervention programs with unsupervised exercise improve outcomes in adults with metabolic syndrome. A systematic review and meta-analysis.

To determine whether lifestyle intervention programs comprising dietary intervention and prescribed, unsupervised exercise improve outcomes for people with metabolic syndrome. A systematic review and meta-analysis of randomised controlled trials. Online databases CINAHL, MEDLINE, PubMed and Embase were searched from the earliest date available to October 2020. Post-intervention data were pooled to calculate mean differences (MD) or standardised mean differences (SMD) and 95% confidence intervals (CI) using inverse variance methods and random effects models. Trial methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale and overall quality of each meta-analysis was assessed using the Grading of Recommendation Assessment, Development and Evaluation approach. Eleven studies from 9 randomised controlled trials with 1,835 participants were included. There was high quality evidence that lifestyle intervention programs with unsupervised exercise reduced waist circumference (MD -2.82 cm, 95%CI -5.64 to 0.00, I2 91%) and blood pressure (systolic: MD -3.89 mmHg, 95%CI -5.19 to -2.58, I2 4%; diastolic: MD -3.16 mmHg, 95%CI -4.83 to -1.49, I2 50%) and increased physical activity levels (SMD 0.47, 95%CI 0.24 to 0.70, I2 45%) when compared to usual care. There was low quality evidence that they improved quality of life (SMD 0.59, 95%CI 0.05 to 1.13, I2 84%). Unsupervised programs had no significant effect on fasting blood glucose (unless > 3 months duration), metabolic syndrome prevalence or cholesterol. Lifestyle intervention programs with prescribed, unsupervised exercise are a practical alternative to supervised programs for people with metabolic syndrome when time, access or resources are limited or when social distancing is required.