Background: Observational studies have reported a high prevalence of obesity and diabetes in subjects on methadone therapy; there are, however, limited data about metabolic syndrome. The aim of the study was to evaluate the prevalence of metabolic syndrome and related factors in individuals with heroin use disorder on methadone therapy.
Methods: A cross-sectional study in individuals with heroin use disorder on methadone therapy at a drug abuse outpatient center. Medical examinations and laboratory analyses after a 12-hour overnight fast were recorded. Metabolic syndrome was diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria.
Results: One hundred and twenty-two subjects were included, with a mean age of 46.1 ± 9 years, a median body mass index (BMI) of 25.3 kg/m2 (interquartile range [IQR]: 21.2-28), and 77.9% were men. Median exposure to methadone therapy was 13 years (IQR: 5-20). Overweight and obesity were present in 29.5% and 17.2% of the participants, respectively. Metabolic syndrome components were low high-density lipoprotein (HDL) cholesterol (51.6%), hypertriglyceridemia (36.8%), high blood pressure (36.8%), abdominal obesity (27.0%), and raised blood glucose levels (18.0%). Abdominal obesity was more prevalent in women (52% vs. 20%, P = >0.01) and high blood pressure more prevalent in men (41.1% vs. 22.2%, P = .07). Prevalence of metabolic syndrome was 29.5% (95% confidence interval [CI]: 16.6-31.8). In the multivariate logistic regression analysis, BMI (per 1 kg/m2 increase odds ratio [OR]: 1.49, 95% CI: 1.27-1.76) and exposure time to methadone therapy (per 5 years of treatment increase OR: 1.38, 95% CI: 1.28-1.48) were associated with metabolic syndrome.
Conclusions: Overweight and metabolic syndrome are prevalent findings in individuals with heroin use disorder on methadone therapy. Of specific concern is the association of methadone exposure with metabolic syndrome. Preventive measures and clinical routine screening should be recommended to prevent metabolic syndrome in subjects on methadone therapy.
Keywords: Heroin use disorder; metabolic syndrome; methadone.