Kyphosis and Sleep Characteristics in Older Persons: The Rancho Bernardo Study.

Che Wankie

doi:10.23937/2572-4053.1510004

Abstract

Kyphosis is a forward curvature of the thoracic spine that is associated with multiple adverse health outcomes. This cross-sectional study examined the association between kyphosis and sleep characteristics. Participants were 468 white, community-dwelling individuals (women = 255; men = 213) from the Rancho Bernardo cohort who had kyphosis assessed using a flexicurve ruler at a 2007-09 follow-up research clinic visit and sleep quality assessed by mailed survey in 2010 with the Pittsburgh Sleep Quality Index (PSQI), scored 0-18, with >5 indicative of poor sleep quality. Women had a mean age of 73.3 ± 8.8 years; men 74.2 ± 8.1 years. Mean flexicurve measures were 12.6 ± 3.2 for women and 12.1 ± 2.6 for men. No significant associations were found between kyphosis and any self-reported sleep measure in men, but women with worse kyphosis had poorer sleep quality, based on total PSQI score and two PSQI subcomponents. In women, with each unit increase in kyphosis, after adjusting for age, marital status, height, general health, calcium supplement use, estrogen use, exercise, arthritis, and depression, there was an associated increase in total PSQI score, indicating worse sleep quality (standard β-estimate = 1.37, 95% CI: 1.03, 1.82). Women with worse kyphosis were also more likely to sleep ≤ 7 hours (Odds Ratio (OR) = 1.11, 95% CI: 1.02, 1.22) and report use of sleep medications (OR = 1.14, 95% CI: 1.03, 1.25). In women only, those with worse flexicurve kyphosis had worse scores on the PSQI, slept fewer hours (≤ 7 hours) and were more likely to report sleep medication use than those with less kyphosis. The association between kyphosis and objective sleep measures in older persons deserves further investigation.

Highlights

Accentuated kyphosis, popularly known as the dowager’s hump, is a forward curvature of the thoracic spine that appears as a humped or crooked back [1,2]
Three models were examined for each sleep quality outcome: unadjusted, age-adjusted, and the full model that included all candidate variables that met the screening criteria of being associated with sleep quality
Among men, compared to those who reported good sleep quality, those with poor sleep quality had a higher prevalence of arthritis

Summary

Introduction

Accentuated kyphosis, popularly known as the dowager’s hump, is a forward curvature of the thoracic spine that appears as a humped or crooked back [1,2]. Hyperkyphosis has been associated with falls, fractures, disability, and mortality [5–9]. Thoracic kyphosis is associated with mild back pain and restricted respiratory function [4,10]. Given these previous observations, it is conceivable that hyperkyphosis associated with physical discomforts including impaired respiratory function may contribute to the deterioration of sleep quality. Sleep changes may occur with age alone, it is plausible that the sleep-wake schedule of persons with kyphosis may be further altered due to weak spinal extensor muscles, disturbed breathing patterns, and pressure exerted on the diaphragm which may make sleep an uncomfortable experience. Complications from poor sleep might serve as an explanation for some of the previously described associations of hyperkyphosis with poor physical functioning, falls, fractures, and earlier mortality

Participants

Procedures

Results

Discussion