AHA/ACC-defined stage 1 hypertensive adults do not display cutaneous microvascular endothelial dysfunction

Area of Science:

• Cardiovascular Science
• Hypertension Research
• Endothelial Function Studies

Background:

• The 2017 AHA/ACC guidelines redefined stage 1 hypertension, but its impact on microvascular endothelial dysfunction is unclear.
• Endothelial dysfunction, particularly nitric oxide (NO)-dependent dilation, is a key factor in hypertension pathogenesis.
• Assessing endothelial function across hypertension stages is crucial for understanding disease progression.

Purpose of the Study:

• To determine if cutaneous microvascular endothelial dysfunction is present in stage 1 hypertension (HTN1) compared to normotensive adults (NTN).
• To compare the severity of endothelial dysfunction in HTN1 and stage 2 hypertension (HTN2).
• To investigate if impairments in NO-dependent dilation mediate this graded dysfunction.

Main Methods:

• Retrospective analysis of 20 NTN, 22 HTN1, and 44 HTN2 adults.
• 24-h ambulatory blood pressure monitoring to assess BP and nocturnal dipping status.
• Laser Doppler flowmetry during microdialysis with acetylcholine (ACh) and L-NAME to measure NO-dependent dilation.

Main Results:

• ACh-induced vasodilation was impaired in HTN2 (P < 0.01) but not HTN1 (P = 0.85) compared to NTN.
• Reductions in NO-dependent dilation were observed in HTN2 (P < 0.01) but not HTN1 (P = 0.76).
• Endothelium-dependent dilation was impaired in non-dippers, irrespective of hypertension classification (P < 0.05).

Conclusions:

• Functional impairments in NO-mediated endothelium-dependent dilation are not evident in stage 1 hypertension.
• Lack of nocturnal blood pressure dipping is associated with blunted endothelium-dependent dilation, regardless of hypertension stage.
• This study provides the first pharmacological assessment of endothelial function in adults classified by 2017 AHA/ACC hypertension guidelines.