Premium
Reductions in Microvascular Function can be Detected by Near‐infrared Spectroscopy (NIRS) following Ischemia‐Reperfusion in Early Postmenopausal Women
Author(s) -
Somani Yasina B.,
Soares Rogerio N.,
Gosalia Jigar,
Delgado Jocelyn,
Murias Juan M.,
Proctor David N.
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.07050
Subject(s) - brachial artery , medicine , endothelial dysfunction , forearm , cardiology , ischemia , menopause , estrogen , reactive hyperemia , reperfusion injury , blood flow , urology , endocrinology , surgery , blood pressure
The onset of menopause and accompanying changes to ovarian hormones often precedes endothelial dysfunction in women. In particular, accelerated impairments in microvascular function coincides with the loss of estrogen, as does impaired endothelial resilience to ischemia‐reperfusion (IR) injury. In early postmenopausal women (4 ± 1 years since menopause), we tested the hypothesis that the NIRS‐derived measurement of vascular responsiveness (reoxygenation slope, %.s −1 ) in the forearm could detect reductions in microvascular function following whole‐arm IR injury. In conjunction, brachial artery flow‐mediated dilation (FMD) and shear rate (area under curve; AUC peak ) were measured. Thirteen healthy, normotensive (116 ± 11/72 ± 9 mmHg) postmenopausal women (57 ± 3 years) were tested before (Pre IR ), after (Post IR ), and 15 minutes following IR (Post 15 ). The IR injury was achieved by inflating a cuff around the upper‐arm to 250 mmHg for 20 min followed by 15 min of reperfusion. The NIRS‐derived reoxygenation slope was lower Post IR (1.02 ± 0.56%.s −1 vs. 1.23 ± 0.64%.s −1 Pre IR ; p =0.04), but not at Post 15 (1.17 ± 0.51%.s −1 ; p =0.08). Brachial artery FMD was lower Post IR (3.57 ± 0.52% vs. 8.14 ± 2.44% Pre IR ; p < 0.001), but not at Post 15 (7.61 ± 1.89%; p = 0.54). Shear AUC peak were similar across tests ( p >0.05). Our findings suggest that the NIRS‐derived reoxygenation slope is a non‐invasive method that may detect transient impairments in forearm microvascular function, and may also be used to assess efficacy of therapeutic interventions in improving both vascular function and resilience in this population. Support or Funding Information Penn State Human Health and Development Endowment AwardSchematic of study timeline