A brief submaximal isometric exercise test 'unmasks' systolic and diastolic masked hypertension

An exaggerated blood pressure (BP) response during dynamic exercise testing has been proposed as an additional screening tool to identify systolic masked hypertension (masked-HYP). However, masked-HYP in young people is often characterized by an elevated DBP. Static/isometric exercise elicits augmented sympathetic stimulation causing greater increases in both SBP and DBP than dynamic exercise.

To examine whether individuals with masked-HYP exhibit exaggerated BP responses during a submaximal handgrip vs. normotensive individuals and individuals with sustained hypertension (true-HYP), and the possible associations of exercise BP with total peripheral resistance (TPR), central/aortic BP, and 24-h-ambulatory BP (24-h BP).

Eighty-six participants [untreated, newly diagnosed, masked-HYP (n = 27), true-HYP (n = 31), and normotensive individuals (n = 28); 46.3 ± 10.7 years], following evaluation of office BP, central/aortic BP, pulse wave velocity, carotid intima-media thickness, echocardiocardiography, and 24-h BP, underwent a 3-min handgrip (30% maximal voluntary contraction) with beat-by-beat BP and hemodynamics assessment (Finapres Medical Systems).

Despite similar baseline-BP in masked-HYP and normotensive individuals, during exercise masked-HYP exhibited a markedly greater (P < 0.01) SBP and DBP vs. normotensive individuals, and similar BP to true-HYP. TPR significantly increased (P < 0.001) during exercise, in masked-HYP and true-HYP. The exaggerated BP responses in masked-HYP were evident from the 1st minute of exercise and correlated (P < 0.05) with central/aortic-BP, aortic stiffness, 24-h BP, day-BP, night-time-BP, and interventricular septum thickness.

During handgrip, masked-HYP exhibited exaggerated BP and TPR responses, similar to those of true-HYP. These responses were evident from the 1st minute of exercise and correlated with 24-h BP, suggesting that systolic and diastolic masked-HYP can be 'unmasked' during a brief, submaximal, handgrip test.