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Analysis of A-phase subtypes during sleep intervals and NREM stages based on gender. Average number of A-phase subtypes per hour of NREM sleep across consecutive 90-min intervals (top), as well as NREM sleep stages (bottom) for men (left) and women (right) with identical age distribution in Osteoporotic Fractures in Men (MrOS), Study and Study of Osteoporotic Fractures (SOF), respectively.
