Introduction Although the Diabetes Prevention Program and other clinical trials demonstrated the efficacy of intensive lifestyle interventions (ILI) and metformin to prevent Type 2 diabetes, no studies have tested their comparative effects in pragmatic settings. This study was designed to compare the real-world effectiveness of ILI, metformin, and standard care among Hispanic women (Latinas) with prediabetes. Study design RCT. Setting/participants Ninety-two Latinas, who had a mean hemoglobin A1c of 5.9%, BMI of 33.3 kg/m2, and waist circumference of 97.4 cm, were recruited from an urban community and randomly assigned to ILI, metformin, or standard care using 1:1:1 allocation. Data were collected from 2013–2015 and analyzed in 2016. Intervention The 12-month ILI was adapted from the Diabetes Prevention Program’s ILI and delivered by community health workers (promotoras) over 24 sessions. Metformin participants received 850 mg twice daily. Those randomized to standard care continued their regular medical care. Main outcome measures Weight and secondary outcomes (waist circumference, blood pressure, hemoglobin A1c, fasting plasma glucose, insulin, and lipids) were assessed at baseline and 12 months. Results ILI participants demonstrated significantly greater mean weight loss (−4.0 kg, 5.0%) than metformin (−0.9 kg, 1.1%) and standard care participants (+0.8 kg, 0.9%) (p<0.001). The difference in weight loss between metformin and standard care was not significant. The ILI group experienced a greater reduction in waist circumference than standard care (p=0.001), and a marginal improvement in hemoglobin A1c compared with metformin and standard care (p=0.063). Conclusions In the first comparative effectiveness trial of diabetes prevention treatments, a 12-month ILI produced significantly greater weight loss than metformin and standard care among Latinas with prediabetes. These data suggest that ILI delivered by promotoras is an effective strategy for preventing diabetes in this high-risk group, which may be superior to metformin. Future pragmatic trials involving larger samples should examine differences in diabetes incidence associated with these treatments.

Purpose The purpose of this pilot study is to test the feasibility, acceptability, and preliminary effectiveness of a Promotora-Led Diabetes Prevention Program (PL-DPP) in Hispanic women (Latinas). Methods Twenty Latina adults with prediabetes were enrolled in this single-arm pilot trial of PL-DPP. Participants underwent a year-long lifestyle intervention consisting of 24 sessions divided into 14 weekly core sessions and 10 post-core sessions offered either biweekly or monthly. Each session was led by a promotora in Spanish. The primary outcome was weight change over the 12-month study period. Results The study participants were socioeconomically challenged, middle-aged Latinas with limited access to health care. Eighteen participants (90%) completed at least 12 sessions, and 1 was lost to follow-up. Overall, participants reported high levels of satisfaction with PL-DPP. At 12 months, the participants achieved a mean weight loss of 10.8 pounds, which corresponded to 5.6% of initial body weight. Significant pre-post reductions in waist circumference, diastolic blood pressure, LDL cholesterol, and insulin levels were also observed. Modest reductions in A1C and fasting plasma glucose were not significant. Conclusions The PL-DPP demonstrated feasibility, acceptability, and preliminary effectiveness in a high-risk population of Latinas. Future research examining this intervention in a randomized clinical trial should explore factors impacting its effects using both qualitative and quantitative methods.

IntroductionUS Latinos are growing at the fastest rate of any racial/ethnic group in the United States and have the highest lifetime risk of diabetes. Acculturation may increase the risk of diabetes among all Latinos, but this hypothesis has not been studied in a nationally representative sample. The objective of this study was to test the hypothesis that acculturation was associated with an increased risk of diabetes in such a sample.MethodsWe conducted a cross-sectional analysis including 3,165 Latino participants in the 2007–2010 National Health and Nutrition Examination Survey. Participants with doctor-diagnosed diabetes and participants without diagnosed diabetes who had glycated hemoglobin (HbA1C) values of 6.5% or higher were classified as having diabetes. An acculturation score, ranging from 0 (lowest) to 3 (highest), was calculated by giving 1 point for each of 3 characteristics: being born in the United States, speaking predominantly English, and living in the United States for 20 years or more. Logistic regression was used to determine the association between acculturation and diabetes.ResultsThe prevalence of diabetes among Latinos in our sample was 12.4%. After adjusting for sociodemographic factors, the likelihood of diabetes (95% confidence interval [CI]) increased with level of acculturation— 1.71 (95% CI, 1.31–2.23), 1.63 (95% CI, 1.11–2.39), and 2.05 (95% CI, 1.27–3.29) for scores of 1, 2, and 3, respectively. This association persisted after further adjustment for body mass index (BMI), total dietary calories, and physical inactivity.ConclusionAcculturation was associated with a higher risk of diabetes among US Latinos, and this risk was only partly explained by BMI and weight-related behaviors. Future research should examine the bio-behavioral mechanisms that underlie the relationship between acculturation and diabetes in Latinos.

Promotora Effectiveness Versus Metformin Trial (PREVENT-DM) is a randomized comparative effectiveness trial of a lifestyle intervention based on the Diabetes Prevention Program delivered by community health workers (or promotoras), metformin, and standard care. Eligibility criteria are Hispanic ethnicity, female sex, age ≥20 years, fluent Spanish-speaking status, BMI ≥23kg/m2, and prediabetes. We enrolled 92 participants and randomized them to one of the following three groups: standard care, DPP-based lifestyle intervention, or metformin. The primary outcome of the trial is the 12-month difference in weight between groups. Secondary outcomes include the following cardiometabolic markers: BMI, waist circumference, blood pressure, and fasting plasma glucose, hemoglobin A1C (HbA1c), total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, and insulin. PREVENT-DM participants are socioeconomically disadvantaged Latinas with a mean annual household income of $15,527 ± 9,922 and educational attainment of 9.7 ± 3.6 years. Eighty-six percent of participants are foreign born, 20% have a prior history of gestational diabetes, and 71% have a first-degree relative with diagnosed diabetes. At baseline, PREVENT-DM participants had a mean age of 45.1 ± 12.5 years, weight of 178.8 ± 39.3lbs, BMI of 33.3 ± 6.5kg/m2, HbA1c of 5.9 ± 0.2%, and waist circumference of 97.4 ± 11.1cm. Mean baseline levels of other cardiometabolic markers were normal. The PREVENT-DM study successfully recruited and randomized an understudied population of Latinas with prediabetes. This trial will be the first U.S. study to test the comparative effectiveness of metformin and lifestyle intervention versus standard care among prediabetic adults in a “real-world” setting.