Hyperkyphosis and self-reported and objectively measured sleep quality in older men

OBJECTIVES: Hyperkyphosis is associated with restricted pulmonary function and posture, potentially contributing to poor sleep. A previous study reported older women with hyperkyphosis had worse self-reported sleep quality, but it is less clear if this association exists in men. We examined the association between hyperkyphosis and subjective and objective sleep quality in a cohort of older men. DESIGN: Longitudinal analysis of data from large cohort of older men participating in the Osteoporotic Fractures in Men Study (MrOS). SETTING: Community. PARTICIPANTS: We studied 754 men participants in MrOS who had kyphosis measured during the 3(rd) clinic visit (2007–2009) and future subjective and objective sleep quality assessed between 2009–2012 (an average of 2.9 years later). INTERVENTION: N/A. MEASUREMENTS: To measure kyphosis, 1.7 cm thick wooden blocks were placed under the participant’s head to achieve a neutral spine position while lying supine on a DXA table. We collected data on both subjective (Pittsburgh Sleep Quality Index [PSQI], and Epworth Sleepiness Scale [ESS]) and objective (wrist actigraphy: Total Sleep Time [TST], Wake After Sleep Onset [WASO], Sleep Efficiency [SE], Sleep Onset Latency [SOL]; and polysomnography: Apnea Hypopnea Index [AHI]) sleep measurements. Those who required >3 blocks were considered hyperkyphotic (n = 145 or 19.2%). RESULTS: In unadjusted and multivariable analyses, men with hyperkyphosis did not report having worse self-reported sleep characteristics based on PSQI and ESS. Similarly, there were no significant associations between hyperkyphosis and objective sleep measures. When examined as a continuous predictor (blocks ranging from 0–8), results were no different. CONCLUSIONS: Although we hypothesized that poor posture in those with hyperkyphosis would interfere with sleep, in this sample of older men, worse kyphosis was not associated with self-reported or objectively measured poor sleep quality.