Effects of Isotretinoin on bone density and Calcium homeostasis in patients with Acne Vulgaris

Background and aim: Side effects of long-term systemic isotretinion use with high accumulative doses on skeletal system have been known, but there are few studies about the effects of short term isotretinoin therapy for acne patients. This study was aimed to recognize the effects of systemic isotretinion on calcium homeostasis and bone density in acne patients referring to clinics affiliated to the Skin Research Center of Shahid Beheshti University of Medical Sciences.Materials and Methods: In this before and after clinical trial, 20 patients with severe acne vulgaris in whom systemic treatment with isotretinoin was indicated were assessed. They included 13 female and 7 male patients with a mean age of 24.3±4.7 years. Serum levels of calcium, phosphorus and alkaline phosphatase as well as lumbar and hip bone mineral density (BMD) of the patients were evaluted before and after treatment with 120 mg/kg total dose of isotretinion. Results were analysed using Wilcoxon signed ranked test before and after treatment and P values less than 0.05 were considered statistically significant.Results: The mean levels of serum calcium and alkaline phosphatase were decreased after treatment course while the mean level of serum phosphorus was increased in comparison to their mean levels before the treatment but the changes were statistically non-significant. BMD of neck and total femur showed no significant difference, but trivial increase (0.0151 gr/cm2) was detected in lumbar BMD after treatment (P<0.05).Conclusion: Considering no significant change in neck and total femur BMD and trivial and clinically unimportant increase in lumbar BMD (L2-L4), it seems that 120 mg/kg total dose of isotretinion that is used for acne has no significant effect on skeletal system.