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Valerio A, Demarchi D, O’Flynn B, Motto Ros P, Tedesco S. Development of a Personalized Multiclass Classification Model to Detect Blood Pressure Variations Associated with Physical or Cognitive Workload. SENSORS (BASEL, SWITZERLAND) 2024; 24:3697. [PMID: 38894487 PMCID: PMC11175227 DOI: 10.3390/s24113697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 05/23/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
Comprehending the regulatory mechanisms influencing blood pressure control is pivotal for continuous monitoring of this parameter. Implementing a personalized machine learning model, utilizing data-driven features, presents an opportunity to facilitate tracking blood pressure fluctuations in various conditions. In this work, data-driven photoplethysmograph features extracted from the brachial and digital arteries of 28 healthy subjects were used to feed a random forest classifier in an attempt to develop a system capable of tracking blood pressure. We evaluated the behavior of this latter classifier according to the different sizes of the training set and degrees of personalization used. Aggregated accuracy, precision, recall, and F1-score were equal to 95.1%, 95.2%, 95%, and 95.4% when 30% of a target subject's pulse waveforms were combined with five randomly selected source subjects available in the dataset. Experimental findings illustrated that incorporating a pre-training stage with data from different subjects made it viable to discern morphological distinctions in beat-to-beat pulse waveforms under conditions of cognitive or physical workload.
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Affiliation(s)
- Andrea Valerio
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy;
| | - Danilo Demarchi
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy;
| | - Brendan O’Flynn
- Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland; (B.O.); (S.T.)
| | - Paolo Motto Ros
- Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Torino, Italy;
| | - Salvatore Tedesco
- Tyndall National Institute, University College Cork, Lee Maltings Complex, Dyke Parade, T12R5CP Cork, Ireland; (B.O.); (S.T.)
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Klop M, de Heus RAA, Maier AB, van Alphen A, Floor-Westerdijk MJ, Bronkhorst M, Melis RJF, Meskers CGM, Claassen JAHR, van Wezel RJA. Capturing postural blood pressure dynamics with near-infrared spectroscopy-measured cerebral oxygenation. GeroScience 2023; 45:2643-2657. [PMID: 37041313 PMCID: PMC10651596 DOI: 10.1007/s11357-023-00791-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/31/2023] [Indexed: 04/13/2023] Open
Abstract
Orthostatic hypotension (OH) is highly prevalent in older adults and associated with dizziness, falls, lower physical and cognitive function, cardiovascular disease, and mortality. OH is currently diagnosed in a clinical setting with single-time point cuff measurements. Continuous blood pressure (BP) devices can measure OH dynamics but cannot be used for daily life monitoring. Near-infrared spectroscopy (NIRS) has potential diagnostic value in measuring cerebral oxygenation continuously over a longer time period, but this needs further validation. This study aimed to compare NIRS-measured (cerebral) oxygenation with continuous BP and transcranial Doppler-measured cerebral blood velocity (CBv) during postural changes. This cross-sectional study included 41 participants between 20 and 88 years old. BP, CBv, and cerebral (long channels) and superficial (short channels) oxygenated hemoglobin (O2Hb) were measured continuously during various postural changes. Pearson correlations between BP, CBv, and O2Hb were calculated over curves and specific characteristics (maximum drop amplitude and recovery). BP and O2Hb only showed good curve-based correlations (0.58-0.75) in the initial 30 s after standing up. Early (30-40 s) and 1-min BP recovery associated significantly with O2Hb, but no consistent associations were found for maximum drop amplitude and late (60-175 s) recovery values. Associations between CBv and O2Hb were poor, but stronger for long-channel than short-channel measurements. BP associated well with NIRS-measured O2Hb in the first 30 s after postural change. Stronger associations for CBv with long-channel O2Hb suggest that long-channel NIRS specifically reflects cerebral blood flow during postural transitions, necessary to better understand the consequences of OH such as intolerance symptoms.
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Affiliation(s)
- Marjolein Klop
- Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Rianne A A de Heus
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Andrea B Maier
- Department of Human Movement Sciences, @AgeAmsterdam, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Centre for Healthy Longevity, @AgeSingapore, National University Health System, Singapore, Singapore
| | - Anne van Alphen
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | | | - René J F Melis
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Carel G M Meskers
- Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam University Medical Center, Amsterdam, the Netherlands
| | - Jurgen A H R Claassen
- Department of Geriatric Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Richard J A van Wezel
- Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands
- Department of Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, the Netherlands
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Newman L, O'Connor JD, Nolan H, Reilly RB, Kenny RA. Age and sex related differences in orthostatic cerebral oxygenation: Findings from 2764 older adults in the Irish Longitudinal Study on Ageing (TILDA). Exp Gerontol 2022; 167:111903. [PMID: 35902001 DOI: 10.1016/j.exger.2022.111903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 04/29/2022] [Accepted: 07/19/2022] [Indexed: 11/18/2022]
Abstract
AIMS Cerebral hypoperfusion is implicated in the pathogenesis of associations between orthostatic hypotension and adverse outcome such as falls, cognitive impairment, depression, and mortality. Although the blood pressure response to orthostasis has been well studied there is a lack of information on orthostatic cerebrovascular responses in older populations. METHODS AND RESULTS We measured cerebral hemodynamics, utilizing near infrared spectroscopy, coupled with peripheral blood pressure during an active stand in a large population of well-phenotyped older adults (N = 2764). Multi-level mixed effect models were utilized to investigate associations with age and sex, as well as confounders including anti-hypertensive medications. Normative cerebral oxygenation responses were also modelled utilizing generalized additive models for location, scale, and shape (GAMLSS). Older age groups experienced larger initial drops in oxygenation and a slower recovery, and responses also differed by sex. The drop after standing ranged from -1.85 % (CI: -2.02 to -1.68) in the males aged 54-59 years vs -1.15 % (CI: -1.31 to -1.00 %) in females aged 54-59 years, to -2.67 % (CI: -3.01 to -2.33) in males aged ≥ 80 years vs -1.97 % (CI: -2.32 to -1.62) females aged ≥ 80 years. Reduced oxygenation levels were also evident in those taking anti-hypertensive medications. CONCLUSION Cerebral autoregulation is impaired with age, particularly in older women and those taking anti-hypertensives. SBP during the stand explained some of the age gradient in the late recovery stage of the stand for the oldest age group. Reported orthostatic symptoms did not correlate with hypoperfusion. Therefore, measures of orthostatic cerebral flow should be assessed in addition to peripheral BP in older patients irrespective of symptoms. Further studies are required to investigate the relationship between NIRS measurements and clinical outcomes such as falls, cognitive impairment and depression.
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Affiliation(s)
- Louise Newman
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin 2, Ireland.
| | - John D O'Connor
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin 2, Ireland
| | - Hugh Nolan
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin 2, Ireland
| | - Richard B Reilly
- Trinity Centre for Biomedical Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - Rose Anne Kenny
- The Irish Longitudinal Study on Ageing, Trinity College Dublin, Dublin 2, Ireland; Mercer's Institute for Successful Ageing, St James's Hospital, Dublin, Ireland
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Zienkiewicz A, Favre M, Ferdinando H, Iring S, Serrador J, Myllylä T. Blood pressure wave propagation - a multisensor setup for cerebral autoregulation studies. Physiol Meas 2021; 42. [PMID: 34731844 DOI: 10.1088/1361-6579/ac3629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 11/03/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Cerebral autoregulation is critically important to maintain proper brain perfusion and supply the brain with oxygenated blood. Non-invasive measures of blood pressure (BP) are critical in assessing cerebral autoregulation. Wave propogation velocity may be a useful technique to estimate BP but the effect of the location of the sensors on the readings has not been thoroughly examined. In this paper, we were interested to study if propagation velocity of the pressure wave in the direction from the heart to the brain may differ compared with propagation from the heart to the periphery, as well as across different physiological tasks and/or health conditions. Using non-invasive sensors simultaneously placed on different locations of the human body allow for the study of how propagation velocity of the pressure wave, based on pulse transit time (PTT), varies across different directions. APPROACH We present multi-sensor BP wave propagation measurement setup aimed for cerebral autoregulation studies. The presented sensor setup consists of three sensors, one each placed on the neck, chest and finger, allowing simultaneous measurement of changes in BP propagation velocity towards the brain and to the periphery. We show how commonly tested physiological tasks affect the relative changes of PTT and correlations with BP. MAIN RESULTS We observed that during maximal blow, valsalva and breath hold breathing tasks, the relative changes of PTT were higher when PTT was measured in the direction from the heart to the brain than from the heart to the peripherals. In contrast, during a deep breathing task, the relative change in PTT from the heart to the brain was lower. In addition, we present a short literature review of PTT methods used in brain research. SIGNIFICANCE These preliminary data suggest that physiological task and direction of PTT measurement may affect relative PTT changes. Presented three-sensor setup provides an easy and neuroimaging compatible method for cerebral autoregulation studies by allowing to measure BP wave propagation velocity towards the brain vs. towards the periphery.
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Affiliation(s)
- Aleksandra Zienkiewicz
- Optoelectronics and Measurement Techniques Research Unit, University of Oulu, Oulu, FINLAND
| | - Michelle Favre
- Department of Pharmacology, Physiology & Neuroscience, Rutgers The State University of New Jersey, Newark, New Jersey, UNITED STATES
| | - Hany Ferdinando
- Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Pohjois-Pohjanmaa, FINLAND
| | - Stephanie Iring
- Department of Pharmacology, Physiology & Neuroscience, Rutgers The State University of New Jersey, Newark, New Jersey, UNITED STATES
| | - Jorge Serrador
- Department of Pharmacology, Physiology & Neuroscience, Rutgers The State University of New Jersey, Newark, New Jersey, UNITED STATES
| | - Teemu Myllylä
- Optoelectronics and Measurement Techniques Research Unit, University of Oulu, Oulu, FINLAND
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Christopoulos EM, Reijnierse EM, Lange PW, Meskers CGM, Maier AB. Orthostatic Hypotension and Orthostatic Intolerance Symptoms in Geriatric Rehabilitation Inpatients, RESORT. J Am Med Dir Assoc 2021; 22:2468-2477.e2. [PMID: 34478695 DOI: 10.1016/j.jamda.2021.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 08/09/2021] [Accepted: 08/14/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Orthostatic hypotension (OH) and orthostatic intolerance symptoms are common in older community-dwelling adults and are associated with reduced quality of life and detrimental health outcomes. This study aimed to determine the prevalence, co-occurrence and determinants of OH and orthostatic intolerance symptoms in geriatric rehabilitation inpatients. DESIGN Observational, longitudinal cohort, "REStORing the health of acutely unwell adulTs" (RESORT). SETTING AND PARTICIPANTS Geriatric rehabilitation inpatients (n = 1505) of a tertiary teaching hospital in Melbourne, Australia. METHODS OH was defined as a drop in systolic blood pressure by ≥20 mm Hg and/or diastolic blood pressure by ≥10 mm Hg within three 3 of moving from supine to a standing or sitting position. Symptoms were recorded following the 3 minutes. Determinants included sociodemographics, reason for admission, cognitive health, nutritional status, physical performance, frailty, morbidity, medication use, length of stay (LOS), and number of geriatric conditions. Independent t-tests, Mann-Whitney U tests or χ2 tests were used to analyze differences between inpatients with and without OH and symptoms. Logistic regression analyses were used to ascertain the determinants. RESULTS OH and orthostatic intolerance symptoms were prevalent in 19.8% (standing: 21.4%, sitting: 18.2%) and 22.6% (standing: 25.0%, sitting: 20.2%) of inpatients, respectively. Symptoms were reported by 32.8% of inpatients with OH and 20.1% without OH. Higher number of comorbidities and geriatric conditions, low functional independence, and longer LOS were determinants of OH. Female gender, higher number of morbidities and geriatric conditions, low functional independence, depression risk, poor physical performance, musculoskeletal and "other" reasons for admission, and long LOS during geriatric rehabilitation were determinants of symptoms. CONCLUSIONS AND IMPLICATIONS OH and orthostatic intolerance symptoms occur in one-fifth of geriatric rehabilitation inpatients, however, the co-occurrence is low and determinants differ. Poorer health in patients with orthostatic intolerance symptoms highlights the need to assess symptoms in clinical practice, independent of an OH diagnosis.
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Affiliation(s)
- Elena M Christopoulos
- Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Esmee M Reijnierse
- Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Department of Rehabilitation Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Peter W Lange
- Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
| | - Carel G M Meskers
- Department of Rehabilitation Medicine, Amsterdam UMC, VU University Medical Center, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Andrea B Maier
- Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia; Department of Human Movement Sciences, @AgeAmsterdam, Faculty of Behavioural and Movement Sciences, VU University Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands; Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Centre for Healthy Longevity, @AgeSingapore, National University Health System, Singapore.
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O'Connor JD, O'Connell MDL, Knight SP, Newman L, Donoghue OA, Kenny RA. Impaired Stabilisation of Orthostatic Cerebral Oxygenation is Associated with Slower Gait Speed: Evidence from The Irish Longitudinal Study on Ageing. J Gerontol A Biol Sci Med Sci 2021; 77:1216-1221. [PMID: 34331759 PMCID: PMC9159662 DOI: 10.1093/gerona/glab219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Indexed: 11/25/2022] Open
Abstract
Background Cerebral autoregulation (CAR) systems maintain blood flow to the brain across a wide range of blood pressures. Deficits in CAR have been linked to gait speed (GS) but previous studies had small sample sizes and used specialized equipment which impede clinical translation. The purpose of this work was to assess the association between GS and orthostatic cerebral oxygenation in a large, community-dwelling sample of older adults. Method Data for this study came from the Irish Longitudinal Study on Ageing. A near-infrared spectroscopy (NIRS) device attached to the forehead of each participant (n = 2 708) was used to track tissue saturation index (TSI; the ratio of oxygenated to total hemoglobin) during standing. GS was assessed using a portable walkway. Results Recovery was impaired in slower GS participants with a TSI value at 20 seconds (after standing) of −0.55% (95% CI: −0.67, −0.42) below baseline in the slowest GS quartile versus −0.14% (95% CI: −0.25, −0.04) in the fastest quartile. Slower GS predicted a lower TSI throughout the 3-minute monitoring period. Results were not substantially altered by adjusting for orthostatic hypotension. Adjustment for clinical and demographic covariates attenuated the association between but differences remained between GS quartiles from 20 seconds to 3 minutes after standing. Conclusion This study reported evidence for impaired recovery of orthostatic cerebral oxygenation depending on GS in community-dwelling older adults. Future work assessing NIRS as a clinical tool for monitoring the relationship between GS and cerebral regulation is warranted.
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Affiliation(s)
- John D O'Connor
- The Irish Longitudinal Study on Ageing, University of Dublin, Trinity College, Ireland.,The Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, UK
| | - Matthew D L O'Connell
- Department of Population Health Sciences, School of Population Health and Environmental Sciences, King's College London, UK
| | - Silvin P Knight
- The Irish Longitudinal Study on Ageing, University of Dublin, Trinity College, Ireland
| | - Louise Newman
- The Irish Longitudinal Study on Ageing, University of Dublin, Trinity College, Ireland
| | - Orna A Donoghue
- The Irish Longitudinal Study on Ageing, University of Dublin, Trinity College, Ireland
| | - Rose Anne Kenny
- The Irish Longitudinal Study on Ageing, University of Dublin, Trinity College, Ireland
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Newman L, O'Connor JD, Romero-Ortuno R, Reilly RB, Kenny RA. Supine Hypertension Is Associated With an Impaired Cerebral Oxygenation Response to Orthostasis: Finding From The Irish Longitudinal Study on Ageing. Hypertension 2021; 78:210-219. [PMID: 34058851 DOI: 10.1161/hypertensionaha.121.17111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Louise Newman
- The Irish Longitudinal Study on Ageing (L.N., J.D.O., R.R.-O., R.A.K.), Trinity College Dublin, Ireland
| | - John D O'Connor
- The Irish Longitudinal Study on Ageing (L.N., J.D.O., R.R.-O., R.A.K.), Trinity College Dublin, Ireland
| | - Roman Romero-Ortuno
- The Irish Longitudinal Study on Ageing (L.N., J.D.O., R.R.-O., R.A.K.), Trinity College Dublin, Ireland.,Discipline of Medical Gerontology, School of Medicine (R.R.-O., R.B.R., R.A.K.), Trinity College Dublin, Ireland.,Mercer's Institute for Successful Ageing, St. James' Hospital, Dublin, Ireland (R.R.-O., R.A.K.)
| | - Richard B Reilly
- Trinity Centre for Biomedical Engineering (R.B.R.), Trinity College Dublin, Ireland.,Discipline of Medical Gerontology, School of Medicine (R.R.-O., R.B.R., R.A.K.), Trinity College Dublin, Ireland
| | - Rose Anne Kenny
- The Irish Longitudinal Study on Ageing (L.N., J.D.O., R.R.-O., R.A.K.), Trinity College Dublin, Ireland.,Discipline of Medical Gerontology, School of Medicine (R.R.-O., R.B.R., R.A.K.), Trinity College Dublin, Ireland.,Mercer's Institute for Successful Ageing, St. James' Hospital, Dublin, Ireland (R.R.-O., R.A.K.)
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Orthostatic blood pressure recovery associates with physical performance, frailty and number of falls in geriatric outpatients. J Hypertens 2020; 39:101-106. [PMID: 32773650 PMCID: PMC7752240 DOI: 10.1097/hjh.0000000000002617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Blood pressure (BP) recovery after orthostatic hypotension might be important to prevent cerebral hypoperfusion episodes in older adults, and be related to better clinical outcome. The objective was to study the relationship between BP recovery and clinical outcome, that is physical and cognitive performance, frailty and falls, in geriatric outpatients.
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O'Connor JD, O'Connell MDL, Romero-Ortuno R, Hernández B, Newman L, Reilly RB, Kenny RA, Knight SP. Functional Analysis of Continuous, High-Resolution Measures in Aging Research: A Demonstration Using Cerebral Oxygenation Data From the Irish Longitudinal Study on Aging. Front Hum Neurosci 2020; 14:261. [PMID: 32765238 PMCID: PMC7379867 DOI: 10.3389/fnhum.2020.00261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 06/12/2020] [Indexed: 12/16/2022] Open
Abstract
Background: A shift towards the dynamic measurement of physiologic resilience and improved technology incorporated into experimental paradigms in aging research is producing high-resolution data. Identifying the most appropriate analysis method for this type of data is a challenge. In this work, the functional principal component analysis (fPCA) was employed to demonstrate a data-driven approach to the analysis of high-resolution data in aging research. Methods: Cerebral oxygenation during standing was measured in a large cohort [The Irish Longitudinal Study on Aging (TILDA)]. FPCA was performed on tissue saturation index (TSI) data. A regression analysis was then conducted with the functional principal component (fPC) scores as the explanatory variables and transition time as the response. Results: The mean ± SD age of the analysis sample was 64 ± 8 years. Females made up 54% of the sample and overall, 43% had tertiary education. The first PC explained 96% of the variance in cerebral oxygenation upon standing and was related to a baseline shift. Subsequent components described the recovery to before-stand levels (fPC2), drop magnitude and initial recovery (fPC3 and fPC4) as well as a temporal shift in the location of the minimum TSI value (fPC5). Transition time was associated with components describing the magnitude and timing of the nadir. Conclusions: Application of fPCA showed utility in reducing a large amount of data to a small number of parameters which summarize the inter-participant variation in TSI upon standing. A demonstration of principal component regression was provided to allow for continued use and development of data-driven approaches to high-resolution data analysis in aging research.
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Affiliation(s)
- John D O'Connor
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland
| | - Matthew D L O'Connell
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland.,Department of Population Health Sciences, King's College London, London, United Kingdom
| | - Roman Romero-Ortuno
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland.,The Global Brain Health Institute, Trinity College, The University of Dublin, Dublin, Ireland
| | - Belinda Hernández
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland
| | - Louise Newman
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland
| | - Richard B Reilly
- Trinity Centre for Biomedical Engineering, Trinity College, The University of Dublin, Dublin, Ireland
| | - Rose Anne Kenny
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland
| | - Silvin P Knight
- The Irish Longitudinal Study on Aging, Trinity College, The University of Dublin, Dublin, Ireland
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Mol A, Meskers CG, Niehof SP, Maier AB, van Wezel RJ. Pulse transit time as a proxy for vasoconstriction in younger and older adults. Exp Gerontol 2020; 135:110938. [DOI: 10.1016/j.exger.2020.110938] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/12/2020] [Accepted: 03/26/2020] [Indexed: 12/18/2022]
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