Increases in body mass index and cardiovascular risk factors during methadone maintenance treatment

Objective: This study describes changes in weight and cardiovascular risk factors over time among individuals enrolled in methadone maintenance treatment for opioid use disorder. Demographic and clinical predictors of weight gain were also evaluated. Design: This study was a retrospective chart review evaluating data over a period of 3 years. Setting: Medical records of individuals enrolled in an academic research outpatient methadone maintenance treatment program were reviewed. Patients: Seventy-four individuals who were admitted and retained in methadone maintenance treatment for at least 3 consecutive years were included. Outcome measures: Annual weight was assessed by calculating body mass index (BMI). Changes over time in cardiovascular risk factors of hypertension, diabetes, and hypercholesterolemia were also assessed. Results: The percentage of patients categorized as overweight, obese, or morbidly obese BMI increased from 42 percent (n = 31) at admission to 76 percent (n = 56), 82 percent (n = 61), and 88 percent (n = 65) at 1, 2, and 3 years post-admission, respectively. Hypertension, diabetes, and hypercholesterolemia also tended to increase following admission. BMI increases tended to be greater for those with a higher dose of methadone, as well as for females and Black/African American individuals. No other predictors of weight gain were identified. Conclusions: These data indicate that methadone maintenance treatment is associated with clinically meaningful weight gain and increases in cardiovascular risk factors. Given the importance of methadone maintenance for treatment of opioid use disorder, future research should examine additional predictors and potential mechanisms of weight gain among methadone patients and develop tailored interventions including nutritional knowledge and lifestyle recommendations.