{"doi":"10.1093/ajh/hpab160","title":"Blood Pressure Variability: Not to Be Discounted","abstract":null,"journal":"American Journal of Hypertension","year":2022,"id":612334,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":1,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":277837,"name":"Tara I. Chang","orcid":"0000-0002-4691-1681","position":1,"is_corresponding":false},{"id":1576595,"name":"Katherine M Wang","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Blood Pressure Variability: Not to Be Discounted","abstract":"Arterial blood pressure (BP) is a dynamic parameter characterized by short-term (seconds to minutes) and long-term (days to months to years) variability. Physiologically, BP variability (BPV) helps to maintain homeostasis in the face of various intrinsic neurohumoral and behavioral stimuli as well as extrinsic stimuli.1 Patients with hypertension and their providers have largely focused treatment targets on absolute or mean systolic BP, which strongly associates with morbidity and mortality.2 In more recent decades, studies have emerged showing an association among higher BPV and poorer clinical outcomes, independent of mean BP. Poorer clinical outcomes include stroke, dementia, myocardial infarction, and death.3–6 These studies raise interest in BPV as a potential intervenable target. The association of BPV and kidney outcomes is incompletely understood. Prior studies have associated higher long-term visit-to-visit BPV with increased albuminuria and resistive index,7 kidney function decline,8 chronic kidney disease progression,9 and incident end-stage kidney disease.10–12 However, other studies have shown no association between BPV and albuminuria or end-stage kidney disease.13,14 To help shed additional light on this topic, in this issue of the American Journal of Hypertension, Ernst et al. leverage longitudinal data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial to determine the association between visit-to-visit office BPV and kidney function.15 Recruited participants were 65 years and older, without evidence of cardiovascular comorbidities, and thus considered relatively healthy at baseline. They defined BPV as the within-individual standard deviation of the mean systolic BP obtained from 3 study visits (baseline and first 2 annual study visits), with a mean follow-up time after the second annual visit of 2.02 years. The authors found that participants in the highest BPV tertile had lower estimated glomerular filtration rate and higher urine albumin-to-creatinine ratio at baseline compared with participants in the lowest tertile; however, higher BPV did not have a significant association with incident chronic kidney disease or with estimated glomerular filtration rate or urine albumin-to-creatinine ratio trajectory. The study was well conducted but hampered by the relatively sparse number of BP measurements available to estimate BPV, a limitation acknowledged by the authors. However, currently there are no set standards for how many BP measurements are necessary or optimal when studying BPV, and this lack of a standard definition adds to the challenges of studying this complex phenomenon. Some studies calculate BPV using measurements over several days, while others use serial BP measurements separated by months, or as in this study—years. In a clinical trial, BP measurements may be more frequent and reliably obtained but may be much less frequent when obtained under less protocolized circumstances or when BP was not the central focus of the study. The choice of how to calculate BPV can depend on the number of data sampling points available. For example, BPV can be calculated as the standard deviation of the mean systolic BP, as in this study, but can also be expressed as the coefficient of variation, average real variability, or variation independent of the mean. These estimates correlate with each other to varying degrees.11 Given the nature of observational studies and post hoc analyses leading to methodological differences in recruited study cohorts, study design, and outcome of interests, discordant results are perhaps unsurprising, and it becomes a herculean task to compare studies head-to-head. Because BP can fluctuate physiologically and pathologically for a variety of reasons, it may be optimal to have repeated BP measurements at similar times over a period of months or longer, whether to ascertain the average “usual” BP or to study BPV. Based on modeling simulations, it has been suggested that 7–10 BP readings may allow an accurate and reproducible estimate of usual underlying BP.16 The ability to conduct precise, more frequent BP sampling coupled with standardization in extrapolation of BPV estimates would allow for more robust studies to establish prognostic significance and clinical utility. We look to future technological innovation to provide us with a quick, simple, noninvasive method of collecting accurate and more concentrated BP measurements, akin to current wearable devices approved to extract wrist-based electrocardiograms to study atrial fibrillation.17 The Omron HeartGuide received FDA clearance in 2018 as the first wrist-worn medical device for BP monitoring. This commercially available personal device utilizes an inflatable oscillometric BP cuff that inflates over the radial artery and obtains pulse waveform data to generate a systolic and diastolic BP.18 One potential drawback is that the watch requires the user to hold their device-wearing wrist to their heart, potentially introducing user error. An Italian study recruiting 721 individuals from the general community found that approximately 63% of the cohort had BP discrepancy of at least ±10 mm Hg error at home using a wrist cuff compared with BP measurements obtained at the office.19 The discrepancy was presumed to be due to user error, despite formal training for participants. Numerous companies have BP wearable devices under development, including ones that do not require inflation of a BP cuff.20 These cuffless devices largely rely on an optical sensor to measure pulse transit time, the time interval for a pulse pressure waveform to travel from the heart to a distal artery. The wirelessly transmitted data are then used to calculate the speed at which this pulse travels, also known as the pulse wave velocity, which can be used to approximate BP. The calculations are most accurate when accounting for physiological factors that regulate BP, such as heart rate and properties of the blood vessel.21 Advantages of cuffless instruments include elimination of discomfort and cumbersome features associated with cuff-based devices, such as limb positioning or disturbance upon cuff inflation. Surpassing the limitations of cuff-based methods, users could obtain BP readings in a continuous manner, during physical activity, or while asleep.22 In clinical practice, remote BP telemonitoring can aide patients and providers in screening and diagnosis of BP disorders, guide management, and provide risk assessment.23 Cuffless devices will allow for increased BP sampling and generation of ample data points in which to obtain estimates of BPV. The ease of use and convenience of these devices would help answer questions about whether BPV can be modified by specific interventions and whether outcomes would be improved. However, although many cuffless devices are already available to consumers, they should be rigorously tested and validated for accuracy before being widely implemented. Despite the lack of association between BPV and kidney function in this study, we believe that BPV is still a parameter worthy of further investigation. Prior evidence suggests that higher BPV is associated with a proatherosclerotic process and confers real risk for adverse outcomes.3,11 Further studies could help elucidate the mechanistic role of BP and disease development, and whether BPV is a potential therapeutic target in the management of hypertension such as the timing and choice of antihypertensive medication administration. Progress in BPV research has been hampered by limitations of BP monitoring and lack of standardized definitions. Until these key issues can be addressed, management of BP will and should continue to rely on mean systolic BP for risk assessment and primary and secondary prevention. The authors declared no conflict of interest.","is_dataset_classified":null,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"34622281","pmcid":null,"openalex_id":"https://openalex.org/W3202707466","authors":[],"funders":[],"total_grants":0,"fwci":0.2922,"citation_percentile":0.59299959,"influential_citations":0,"citation_trend":[{"year":2021,"count":1},{"year":2023,"count":1}],"oa_status":"bronze","license":"https://academic.oup.com/pages/standard-publication-reuse-rights","oa_locations":[{"url":"https://academic.oup.com/ajh/article-pdf/35/2/118/46382195/hpab160.pdf","host_type":"journal"},{"url":"https://academic.oup.com/ajh/article-pdf/35/2/118/46382195/hpab160.pdf","host_type":"publisher"},{"url":"http://academic.oup.com/ajh/advance-article-pdf/doi/10.1093/ajh/hpab160/40755609/hpab160.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1093/ajh/hpab160","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/34622281","host_type":"repository"}],"fields_of_study":["Blood Pressure and Hypertension Studies","Hemodynamic Monitoring and Therapy","Heart Rate Variability and Autonomic Control","Blood Pressure"],"mesh_terms":["Blood Pressure"],"keywords":["Medicine","Blood pressure","Cardiology","Internal medicine"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-02T02:56:15.895396Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}