Prevalence and associations of respiratory-related leg movements: the MrOS sleep study

Abstract

Objectives Obstructive respiratory events often terminate with an associated respiratory-related leg movement (RRLM). Such leg movements are not scored as periodic leg movements (PLMS), though the criteria for distinguishing RRLM from PLMS differ between American Academy of Sleep Medicine (AASM) and World Association of Sleep Medicine (WASM)/ International Restless Legs Syndrome Study Group (IRLSSG) scoring manuals. Such LMs may have clinical significance in patients with obstructive sleep apnea (OSA). We examined the prevalence and correlates of RRLM in men with OSA. Methods A case control sample of 575 men was selected from all men with an apnea-hypopnea index (AHI, ≥3% desaturation criteria) ≥ 10 and good data from piezoelectric leg movement sensors at the first home sleep study in the MrOS cohort (mean age=76.8 years). Sleep studies were rescored for RRLMs using five different RRLM definitions varying both latency of leg movement onset from respiratory event termination and duration of the leg movement. Quartile of RRLM% (the number of RRLM/the number of hypopneas+apneas) was derived. Results Nonparametric densities of RRLM% were most influenced by alterations in the latency rather than the duration of the LM. The most liberal RRLM definition (latency 0–5 sec, duration 0.5–10 sec) led to a median RRLM% of 23.4 (IQ range 12.41, 37.12) in this sample. The average AHI and arousal index increased as quartile of RRLM% increased, as well as prevalence of COPD. The prevalence of those with a history of hypertension decreased as RRLM% increased. Non-caucasian race was associated with lower RRLM%. Conclusion Within an elderly sample with moderate to severe OSA, piezoelectric-defined RRLM% is associated with a number of sleep-related and demographic factors. Further study of the optimal definition, predictors and consequences of RRLM is warranted.

Fatigue and disturbances of sleep in patients with osteogenesis imperfecta – a cross-sectional questionnaire study

“…The absence of snoring, however, makes apnea unlikely; only 6% of apnea patients do not snore [ 29 ]. Insomnia and restless legs syndrome are each clinically significant in 5–10% of adults in general population, and an average incidence of 23% of respiratory-related leg movements has been documented in a sleep apnea cohort [ 33 – 35 ]. According to this study, insomnia and restless legs are more frequent in OI population than among unaffected peers.…”

Periodic leg movements during sleep: phenotype, neurophysiology, and clinical significance

“…For example, in patients with RLS, it has been shown that only the periodic LMs respond to dopaminergic treatment and that non-periodic LMs with IMIs <5 s are unaffected [44]. On the other hand, LMs associated with respiratory events may be associated with clinical variables independent of PLMS, such as number of apnea episodes, presence of chronic obstructive pulmonary disease, hypertension and ethnic factors [45]. Thus, the investigation of nocturnal non-periodic leg movement activity deserves further attention.…”

“The Effect of Obstructive Sleep Apnea on Peripheral Blood Amino Acid and Biogenic Amine Metabolome at Multiple Time Points Overnight“

“…That glucose is again released into the blood circulation and taken up by muscles, where it is converted to pyruvate 12 . OSA is known to be associated with increased night-time muscle activity, due to either respiratory-related leg movements secondary to obstructive respiratory events 13 or bathroom visits because of nocturia 3 . Although significantly higher in patients with OSA than in control individuals in our study, the night-time levels of Ala in OSA patients remained nearly stable and not deviating from the evening levels ( Figure 1).…”