Background: It is unknown whether the benefits of intensive lifestyle interventions (ILI) are equally distributed among participants with type 2 diabetes of different races/ethnicities or educational attainment. We hypothesized that individuals of White race/ethnicity and greater educational attainment (EA) would receive greater benefit from ILI within a clinical trial.
Methods: Using data from the Look AHEAD trial which assigned adults with T2D to an ILI or diabetes support and education (DSE) , we examined weight outcomes (achievement of the 7% weight loss goal, percent weight change) , stratified by race/ethnicity and EA. Differences between groups are described using univariate analyses and multivariable linear and logistic regression adjusted for age, sex, treatment arm, and baseline insulin use.
Results: Among 4,640 participants (mean age 59 years, 58% women) , 17% were non-Hispanic Black, 14% were Hispanic, and 13% did not have a high school degree. Black and Hispanic participants were less likely to achieve the weight loss goal in both the ILI (45.8% vs. 60.7%, p<0.0 and 53.0% vs. 60.7%, p=0.01, respectively) and DSE arms of the trial and achieved lesser percent weight loss in the ILI arm. By contrast, participants with lower EA (less than a high school degree) were more likely to achieve the weight loss goal in the ILI but numerically less likely to achieve it in the DSE arm, with evidence of an arm by education interaction (p for interaction 0.015) , suggesting greater benefit from the ILI in this subgroup. Participants with lower EA also achieved greater percent weight change than peers in the ILI at both 1 year and 4 years after randomization, with ongoing evidence of an arm by education interaction at 4 years.
Conclusions: Black and Hispanic participants experienced less weight loss in both arms of the Look AHEAD trial, whereas those with lower EA experienced superior benefits in the ILI compared to other groups. Individuals with low EA may receive relatively greater benefits from ILIs, compared to those with higher EA.
S.Cromer: Other Relationship; Johnson & Johnson Medical Devices Companies, Research Support; National Institute of Diabetes and Digestive and Kidney Diseases. J.B.Meigs: Consultant; Quest Diagnostics. D.J.Wexler: Other Relationship; Elsevier, Novo Nordisk, UpToDate.