the effect of opium dependency on testis volume: a case-control study

background: given the paucity of data on possible testis changes in opioid dependents, we sought to compare the testis volumes between a group of opium dependents and a group of healthy controls. objective: comparison of testis volume between opium dependents and healthy controls. materials and methods: this case-control study recruited 100 men with opium dependency (cases) and 100 healthy men (controls) in iran, in 2008. a checklist containing questions about age, height, weight, daily amount of cigarette use, and duration of cigarette use for all the participants as well as daily amount of opium use (grams) and duration of opium use (years) for the case group was completed. additionally, the dimensions of each testis were measured by a single person using calipers, and the mean of the left and right testes volume was compared between these two groups. results: the mean of the testis volumes in the case group was significantly lower than that of the case group (11.2±2.2 and 25.1±2.7cm³, p<0.001). the results of the ancova test showed that even after the omission of the cigarette smoking effect (p=0.454), the testis volume remained lower in the opium dependents (r2=0.884, p<0.001). in the case group, there were significant reverse correlations between testis volume and age (r=-0.404, p<0.001), daily amount of opium use (r=-0/207, p=0.039) and duration of opium use (r=-0.421, p<0.001). conclusion: we found that the testis volume in the male opium dependents was lower than that of the healthy controls. we would recommend that future studies into the impact of drugs on the testis dimensions pay heed to possible histological changes in the testes owing to opium dependency.