Aerobic exercise training fails to reduce blood pressure in nondipper-type hypertension

Abstract

To assess whether aerobic exercise training is an effective and an alternative method to control blood pressure (BP) in hypertension, 32 uncomplicated, never treated patients suffering from mild-to-moderate essential arterial hypertension (EAH) were included in an aerobic exercise training program using a regular standardized cycle ergometer exercise for 3 months. In all EAH patients, before and after the exercise training period, ambulatory BP monitoring (ABPM) was performed and several metabolic variables were assessed. Before exercise, in 20 EAH patients, a 48-h ABPM showed a normal day-night rhythm, with nocturnal BP decrease, according to a dipper-type hypertension, whereas in 12 EAH patients 48-h ABPM profile indicated a nondipper-type hypertension. After exercise, EAH dippers presented a significant decrease in the daytime systolic and diastolic BP, whereas EAH nondippers did not show any change in daytime and nighttime systolic and diastolic BP. Our study confirms the controversy about the postulated BP lowering effect of dynamic exercise in EAH patients, in the sense that only EAH dipper patients seem to obtain a beneficial diurnal lowering BP effect deriving from exercise, possibly through a reduction in sympathetic tone. On the contrary, physical activity seems to fail in reducing diurnal and nocturnal BP values in EAH nondippers, suggesting that in nondipper-type hypertension, other "masking" endogenous or exogenous factors could interfere with and prevail over the adrenergic-vagal balance that modulates the day-night BP synchronism.

Time of day for exercise on blood pressure reduction in dipping and nondipping hypertension

“…Not only were Non-Dippers found to respond to exercise treatment, but also Non-Dippers reduced their nighttime systolic blood pressure (À10.17 2.70 mmHg) despite the TOD for exercise. The reduction in systolic blood pressure in Non-Dippers contradicts the findings of Nami and collegues, 12 who reported aerobic exercise training failed to reduce blood pressure in nondipping hypertension.…”

“…The additional important findings in this study include: (1) Non-Dippers respond to exercise treatment, (ie both morning and evening exercise produced a reduction in nighttime systolic blood pressure in Non-Dippers) and (2) the duration of the blood pressure reduction appears to be greater than 12 h. Table 6 summarizes these findings in relationship to the literature. Non-Dippers were investigated in the study because (1) they have been identified as nonresponders to exercise 12 and (2) non-dipping hypertension is associated with more serious end-organ damage and higher incidence of cardiovascular complications than Dippers. 11 A single bout of exercise was chosen for this study because it may be the initial step to investigate the effectiveness of exercise on blood pressure reduction in populations previously identified as nonresponders.…”

“…The reproducibility of the dipping and nondipping hypertension is consistent with the study by Nami and collegues. 12 Systolic blood pressure reductions were found in average 24 h, daytime and nighttime systolic blood pressure. No significant reduction was found for diastolic blood pressure.…”

“…8 Hypertensive patients who do not exhibit nocturnal dipping (Non-Dippers: defined as o10% reduction in average nighttime blood pressure compared to average daytime blood pressure) 11 have been identified among the nonresponders to exercise training. 12 Nami et al 12 reported that aerobic exercise training failed to reduce blood pressure in Non-Dippers while it did reduce blood pressure in hypertensive patients who exhibited nocturnal dipping (Dippers). The unresponsiveness of the Non-Dippers to exercise treatment could not be attributed to salt intake and other metabolic factors.…”

“…The unresponsiveness of the Non-Dippers to exercise treatment could not be attributed to salt intake and other metabolic factors. 12 Non-dipping hypertension is associated with a higher degree of cardiovascular complications and more serious end-organ damage than Dipping hypertension. 11 Thus, a more effective exercise programme for Non-Dippers may be warranted.…”