[Weight changes of patients in methadone maintenance treatment during four years period]

Besides significant reduction in heroin consumption, weight gain is an accompanying phenomenon during methadone maintenance treatment. Priority of this on-going study was to find out, if it is stable, or transitory. We were also interested in possible contribution of pharmacological and socio-cultural factors on body weight changes.

It was a longitudinal, clinical, observational study. The sample consisted of 42 patients from methadone maintenance treatment program (MMTP) from the Centre for Treatment of Drug Dependencies in Bratislava. Their average age was 28.6 years (SD ± 6.0); 67 % were males. The weight (kg) and body mass index (BMI) were monitored in the series of five measurements during four years period in MMTP: at treatment entry after one year, after two, after three and after four years in the program. Relationship was also explored between daily dose of methadone and BMI. The average weight of the patients and their BMI were: before the entry into MMTP 65.2 kg (SD ± 13.9) and 22.2 (SD ± 3.9); after one year 72.7 kg (SD ± 15.3) and 24.7 (SD ± 4.1); after two 75.2 kg (SD ± 16.7) and 25.6 (SD ± 4.4); after three 74.2 kg (SD ± 17.1) and 25.1 (SD ± 4.5); after four years 75.0 kg (SD ± 16.5) and 25.2 (SD ± 4.2). Significant increase of BMI was detected after one year (t = 5.03; p < 0.001) and less significant between one and two years (t = 2.5; p < 0.05) in MMTP. Significant difference was also found between proportional distributions of the patients according to BMI categories: underweight, norm, overweight, obesity; at the time of entry to MMTP and after one year in it (χ² = 13.6; p < 0.01). No any other statistically significant changes were found later on, after 1 - 4 years from the entry to the treatment. The correlation between daily dose of methadone and BMI (r = 0.273) was not significant after four years in MMTP.

The weight of the patients in MMTP has increased significantly after one year in the treatment, but remained stable from the second year. No substantial correlation was detected between methadone dose and BMI.