Bone mineral density and bone turnover markers in patients receiving a single course of isotretinoin for nodulocystic acne

Background High-dose isotretinoin has been reported to have adverse effects on bone mineral density (BMD); however, studies evaluating changes in BMD with isotretinoin therapy at different dosages and with varying treatment durations have produced conflicting results. Objective To investigate the effect of a standard, single course of isotretinoin therapy on BMD and bone turnover markers in patients with nodulocystic acne. Methods Thirty-six patients (15 male, 21 female) with severe, recalcitrant, nodulocystic acne and 36 healthy controls (16 male, 20 female) were enrolled in the study. Patients received isotretinoin treatment for 4-6 months until a cumulative dose of 120 mg/kg had been achieved. BMD in the lumbar spine and femur was measured at baseline and at the end of therapy by dual-energy X-ray absorptiometry. Serum calcium, phosphate, parathormone, total alkaline phosphatase, osteocalcin, free deoxypyridinoline, and urinary calcium were also measured before and at the end of treatment. Results No significant differences were found in lumbar spine and femoral BMD between the patient and control groups at the beginning of the study (P > 0.05), and no statistically significant difference was observed between the BMD values in patients at the beginning vs. the end of treatment (P > 0.05). No statistically significant difference in bone turnover markers was found between patients and controls at the beginning of the study (P > 0.05), and no statistically significant changes in bone turnover markers were observed in patients at the beginning vs. the end of treatment (P > 0.05). Conclusion A single course of isotretinoin therapy has no clinically significant effect on bone metabolism.