Nitrogen-bisphosphonate therapy is linked to compromised coenzyme Q10 and vitamin e status in postmenopausal women

Abstract

Background: Nitrogen-bisphosphonates (N-BPs) are the most widely used drugs for bone fragility disorders. Long-term or high-dose N-BP use is associated with unusual serious side effects such as osteonecrosis of the jaw, musculoskeletal pain, and atypical fractures of long bones. It has escaped notice that the pathway N-BPs block is central for the endogenous synthesis of coenzyme Q10, an integral enzyme of the mitochondrial respiratory chain and an important lipid-soluble antioxidant. Our objective was to assess the coenzyme Q10 and antioxidant status in relation to N-BP exposure in women with postmenopausal osteoporosis. Methods: Seventy-one postmenopausal women (age, 73.5 ± 5.5 y) with osteoporosis and no other malignancy were included in this cross-sectional study. Seventeen were treatment naive, 27 were on oral N-BP, and 27 were on iv N-BP. Results: Vitamin E γ-tocopherol levels (μmol/mL) were significantly reduced in N-BP users [oral, H(2) = 18.5, P = .02; iv, H(2) = 25.2, P