Ozone decreases sperm quality in systemic lupus erythematosus patients

To investigate the deleterious effects of air pollutants exposure in the Sao Paulo metropolitan region on semen quality in systemic lupus erythematosus (SLE).

A seven-years longitudinal repeated-measures panel study was performed at the Laboratory of Experimental Air Pollution and Rheumatology Division. Two semen samples from 28 post-pubertal SLE patients were analyzed. Daily concentrations of air pollutants exposure: PM10, SO2, NO2, ozone, CO, and meteorological variables were evaluated on 90 days before each semen collection dates using generalized estimating equation models.

Intravenous cyclophosphamide (IVCYC) and ozone had an association with a decrease in sperm quality of SLE patients. IVCYC was associated with decreases of 64.3 million of spermatozoa/mL (95% CI 39.01-89.65; p=0.0001) and 149.14 million of spermatozoa/ejaculate (95% CI 81.93-216.38; p=0.017). With regard to ozone, the most relevant adverse effects were observed from lags 80-88, when the exposure to an interquartile range increase in ozone 9-day moving average concentration led to decreases of 22.9 million of spermatozoa/mL (95% CI 5.8-40.0; p=0.009) and 70.5 million of spermatozoa/ejaculate (95% CI 12.3-128.7; p=0.016). Further analysis of 17 patients that never used IVCYC showed association between exposure to ozone (80-88 days) and decrease of 30.0 million of spermatozoa/mL (95% CI 7.0-53.0; p=0.011) and 79.0 million of spermatozoa/ejaculate (95% CI 2.1-155.9; p=0.044).

Ozone and IVCYC had a consistent adverse effect on semen quality of SLE patients during spermatogenesis. Minimizing exposure to air pollution should be taken into account, especially for patients with chronic systemic inflammatory diseases living in large cities.