Clinical and demographic features of chronic progressive external ophthalmoplegia in a large adult-onset cohort.

Chronic progressive external ophthalmoplegia (CPEO) is a common mitochondrial disease. We evaluated the impact of sex and smoking status upon knee extension strength and the phenotypic spectrum of disease in a large cohort of adult-onset CPEO patients (N=116) using retrospective chart analysis. The CPEO patients showed significantly lower knee extension strength as compared to the age- and sex-matched control population (-37%, P<0.05). Smoking also negatively impacted knee extension strength only in women with CPEO (-26%, P<0.05). We conclude that smoking and female sex interact negatively in CPEO patients.