Leisure and occupational physical activity at different ages and risk of endometriosis

Objective Cohort and case-control studies have suggested that adult physical activity (PA) may lower endometriosis risk and improve symptoms, but evidence is still controversial. To add information on leisure and occupational PA impact, if any, on endometriosis risk, we have analyzed data from a small case-control study conducted in Milan (Italy). Study design Ninety cases and 90 controls (median age 35 years, range 18-76) were compared. Endometriosis was laparoscopically diagnosed within the year before interview. Information on demographic variables, menstrual and reproductive history, occupational and recreational physical activity was collected. Results A consistent protective effect emerged between leisure PA and endometriosis risk. For <2-4 and ≤5 h/week (reference no PA), the estimated odds ratios (ORs) were, respectively: 0.36 (95% CI 0.18-0.74) and 0.83 (95% CI 0.27-2.53) as regards PA in early adolescence; 0.31 (95% CI 0.15-0.63) and 0.78 (95% CI 0.25-2.38) as regards PA in teenage years; 0.34 (95% CI 0.12-0.94) and 0.33 (95% CI 0.08-1.28) for PA in adulthood. However, no significant trend was seen according to hours spent in leisure PA. Occupational PA did not show statistical significant differences among different types or across age classes. Conclusions These results suggest that leisure PA in early adolescence, teenage years and adulthood may, to some extent, decrease the risk of endometriosis. In the interpretation of these results, however, the role of potential biases cannot be totally ruled out.