Early postmenopausal women with cardiovascular risk factors improve microvascular dysfunction after acute estradiol administration.
OBJECTIVE
This study aimed to compare endothelial microcirculatory function in hypertensive and diabetic (HD) and healthy postmenopausal women before and after nasal application of 17β-estradiol.


METHODS
Seventy-one women aged 42 to 59 years within 10 years of menopause, divided into HD (n = 31) and similar-age healthy (n = 40) women were evaluated noninvasively through nailfold videocapillaroscopy before and 1 hour after estradiol, measuring basal (RBCV) and maximum (RBCVmax) red blood cell velocity after 1 minute of arterial occlusion, representing baseline and endothelial-mediated vasodilation, and time to reach RBCVmax (TRBCVmax), representing microvascular compliance/stiffness.


RESULTS
Hot flashes did not differ from or affect microvascular results. Before estradiol, HD showed lower RBCV (1.495 ± 0.20 vs 1.52 ± 0.10 mm/s, P = 0.019), borderline lower RBCVmax (1.655 ± 0.09 vs 1.706 ± 0.10 mm/s, P = 0.054), and shorter TRBCVmax (7.94 ± 1.44 vs 8.8 ± 2.03 s, P = 0.011) compared with healthy women. After estradiol, RBCV and RBCVmax increased, and TRBCVmax decreased in both groups (P = 0.0001 for all). HD women showed a higher RBCV increment (14.6% ± 2% vs 11.1 ± 1.4%, P = 0.021) associated with a smaller TRBCVmax reduction (23.6% ± 2% vs 31% ± 2%, P = 0.045). Changes in RBCVmax did not differ between HD (11.6% ± 1%) and healthy (8.3% ± 1.3%, P = 0.1) women. RBCV, RBCVmax, and TRBCVmax absolute values after estradiol were similar between groups. Past oral contraceptive exposure (P = 0.035) and cigarette smoking (P = 0.047) influenced healthy women's microvascular responses to estradiol, whereas triglyceride levels impaired HD vasodilation (P = 0.028).


CONCLUSIONS
Before estradiol, HD presented impaired microvascular dilation and compliance compared with control women of similar age. After estradiol, HD recovered microvascular endothelial-mediated dilation, reaching similar absolute values, but the smaller reduction in TRBCVmax suggests irreversible microvascular stiffness.
Laboratory for Clinical and Experimental Research on Vascular Biology-BioVasc, Biomedical Center, State University of Rio de Janeiro, Rio de Janeiro, Brazil. rclapauch@uol.com.br
Ruth
R
Clapauch
Anete S
AS
Mecenas
Priscila A
PA
Maranhão
Eliete
E
Bouskela
D000281:Administration, Intranasal; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D002318:Cardiovascular Diseases / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D004958:Estradiol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D055806:Microvessels / Q000187:drug effects* / Q000503:physiopathology*; D008875:Middle Aged; D017698:Postmenopause; D012307:Risk Factors
D004958:Estradiol