Characterization of lung-to-finger circulation time in sleep study assessment: The Multi-Ethnic Study of Atherosclerosis

Younghoon Kwon, Sara Mariani, Sneha R. Gadi, David R. Jacobs, Naresh M. Punjabi, Michelle L. Reid, Ali Azarbarzin, Andrew D. Wellman, Susan Redline

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Objectives: Lung-to-finger circulation time (LFCT) measured from sleep studies may reflect underlying cardiac dysfunction. We aimed to examine the distribution of LFCT in community-dwelling men and women in order to better understand the factors determining LFCT between and within subjects. Approach: We included participants of the Multi-Ethnic Study of Atherosclerosis (MESA) Sleep with polysomnography-based evidence of sleep apnea (defined by apnea hypopnea index >15 hr-1). In a randomly selected subset of the analytical dataset, we tested an automated LFCT measurement method against the visual method. Using the automated method we then scored LFCTs from all eligible respiratory events for all included participants. A multiple regression model was constructed to determine factors independently associated with average LFCT across subjects. We also explored factors that are associated with LFCT within subjects using linear mixed-effect models. Main results: In a subset of the cohort (N = 39) there was a high correlation in average LFCT obtained by automated and visual methods (r = 0.96). In the analysis of 596 participants, men [19.6 (2.8)] (vs. women [17.9 (2.7) s], p < 0.0001) and older age (> 69 (vs. ≤ 69) had longer average LFCT (19.4 [2.8] vs. 18.5 [2.9] s, p < 0.0001). These associations persisted in multivariable analysis. No association was found with body habitus. Within subject analysis revealed trivial associations between apnea/hypopnea duration, apnea (vs. hypopnea), nadir O2 saturation and sleep stages (NREM vs. REM) and individual LFCT. Significance: Automated LFCT measurement was highly correlated with visual-based LFCT measurement. In this group of community-dwelling adults, male sex and older age were associated with higher average LFCT.

Original languageEnglish (US)
Article number065004
JournalPhysiological Measurement
Issue number6
StatePublished - Jun 2020


  • circulation
  • polysomnography
  • sleep apnea
  • sleep study

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Biomedical Engineering
  • Physiology (medical)


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