Current Age, But Not Age Of Menopause, Is Associated With Blood Pressure Reactivity To Isometric Exercise In Postmenopausal Females

Hypertension (HTN) and cardiovascular disease (CVD) risks increase substantially after menopause, and literature suggests that the age at which menopause is completed contributes to this risk. Blood pressure (BP) reactivity to static fatiguing handgrip (HG) exercise can reveal existing HTN and may be valuable in predicting future risk for developing HTN. Thus, we aimed to determine if the age of menopause would contribute to greater BP reactivity during a static fatiguing HG in females. We hypothesized that cardiovascular reactivity would be positively related to age and inversely related to menopause age. METHODS: Participants laid supine throughout testing. Each participant performed a maximum voluntary contraction (MVC) of the hand followed by a 3-min. baseline rest (BL), then a continuous HG at 30% of MVC force to fatigue. Beat-to-beat BP and heart rate (HR) were recorded during BL and HG. Measures of systolic, diastolic, and mean arterial BP (SBP, DBP, and MAP, respectively) and HR were compared at the start, 25%, 50%, 75%, and end of each participant's fatiguing contraction. To further evaluate cardiovascular reactivity, baseline measures of BP and HR were also compared to peak responses. Statistical analyses included repeated-measures ANOVA and Pearson correlation, and results are presented as mean±SD. RESULTS: Eleven postmenopausal females (age 63±4 yrs.; range: 58-69 yrs.), with menopause age of 50±4 yrs. (range: 42-55 yrs.), completed all procedures. Average BL SBP and DBP were 135±14mmHg and 77±9mmHg, respectively. Systolic BP, DBP, MAP, and HR increased from BL throughout the fatiguing contraction (time effect: p≤0.001 for all). Peak values of BP and HR increased from BL (ΔSBP: 55±28mmHg; ΔDBP: 43±24mmHg; ΔMAP: 45±21mmHg; ΔHR: 29±14 bpm; p<0.001 for all tests). Age was correlated with peak increases in SBP, DBP, and MAP (r=0.71, p=0.014; r=0.76, p=0.006; r=0.78, p=0.005, respectively), but not with peak change in HR (p>0.05). Menopause age was not correlated with BP or HR reactivity (p>0.05 for all). CONCLUSION: Although age of menopause appears to be strongly linked to future risk of CVD, we did not observe a significant relationship between cardiovascular reactivity and age of menopause. Instead, findings from this study suggest that current age may provide a stronger indicator of exaggerated BP reactivity and potential increased risk for CVD in females.