Exploratory Analysis of the Variable Response to an Intensive Lifestyle Change Program for Metabolic Syndrome

Abstract

Background Wide variability in response to lifestyle interventions has been recognized for many years, and researchers have begun to disentangle sources of error from inherent differences in individual responsiveness. The objective of this secondary analysis of an intensive lifestyle intervention (diet and exercise) for metabolic syndrome (MetS) was to identify potentially important differences among study completers grouped by treatment response as measured by change in a continuous metabolic syndrome (Gurka/MetS) score. Methods All study completers from a 12-month primary care study were categorized into one of five groups according to change in the Gurka/MetS score. A change of 0.4 in z-score defined clinically relevant change in line with results of previous studies. Repeated measures analysis of covariance was used to examine the Gurka/MetS score over 12 months, looking for differences in response over time by the five groups. Results Of 176 participants, 50% (n = 88) had stable scores, 10% (n = 18) had relevant change scores in the first 3 months only and reverted toward baseline, 20% (n = 35) achieved meaningful change over the whole study, 11% (n = 20) had a delayed response at 3–12 months, and 9% (n = 15) demonstrated worsening scores. Significant response group*time differences were noted (p < 0.001). Improvement in diet quality and fitness scores were similar across all groups. Available other variables did not account for the differences. Conclusion Work is needed to identify key factors that account for differences in responses to lifestyle interventions that can be used to guide treatment decisions for intensive lifestyle interventions for this common condition. Trial Registration ClinicalTrials.gov Identifier: NCT01616563; first registered June 12, 2012.