Mindfulness meditation lowers muscle sympathetic nerve activity and blood pressure in African-American males with chronic kidney disease

Abstract

Mindfulness meditation (MM) is a stress-reduction technique that may have real biological effects on hemodynamics but has never previously been tested in chronic kidney disease (CKD) patients. In addition, the mechanisms underlying the potential blood pressure (BP)-lowering effects of MM are unknown. We sought to determine whether MM acutely lowers BP in CKD patients, and whether these hemodynamic changes are mediated by a reduction in sympathetic nerve activity. In 15 hypertensive African-American (AA) males with CKD, we conducted a randomized, crossover study in which participants underwent 14 min of MM or 14 min of BP education (control intervention) during two separate random-order study visits. Muscle sympathetic nerve activity (MSNA), beat-to-beat arterial BP, heart rate (HR), and respiratory rate (RR) were continuously measured at baseline and during each intervention. A subset had a third study visit to undergo controlled breathing (CB) to determine whether a reduction in RR alone was sufficient in exacting hemodynamic changes. We observed a significantly greater reduction in systolic BP, diastolic BP, mean arterial pressure, and HR, as well as a significantly greater reduction in MSNA, during MM compared with the control intervention. Participants had a significantly lower RR during MM; however, in contrast to MM, CB alone did not reduce BP, HR, or MSNA. MM acutely lowers BP and HR in AA males with hypertensive CKD, and these hemodynamic effects may be mediated by a reduction in sympathetic nerve activity. RR is significantly lower during MM, but CB alone without concomitant meditation does not acutely alter hemodynamics or sympathetic activity in CKD.

Keywords: chronic renal insufficiency; mindfulness meditation; muscle sympathetic nerve activity.

Fig. 1.

Change in systolic blood pressure (SBP, A), diastolic blood pressure (DBP, B), mean arterial pressure (MAP, C), and heart rate (HR, D), during 14 min of mindfulness meditation (MM) versus control intervention. The model equation is given in the text. α₀ represents the mean difference relative to baseline under the control condition at minute 14, and α₁ is the discrepancy in that mean difference for the MM condition relative to the control condition at minute 14. β₀ is the rate of change of the difference from baseline over time under the control condition, whereas β₁ is the discrepancy in that rate of change for the MM condition relative to the control condition. *Significant P values <0.05.

Fig. 2.

Change in muscle sympathetic nerve activity (MSNA) quantified in burst frequency (bursts/min, A) and total activity [arbitrary units (AU)/min, B]. The model equation is given in the text. α₁ represents the discrepancy in the mean difference for the MM condition relative to the control condition at minute 14. β₁ is the discrepancy in the rate of change for the MM condition relative to the control condition. *Significant P values <0.05.

Fig. 3.

SBP, DBP, MAP, and HR (A) and MSNA (B) at baseline and during the 5-min recovery period after a session of MM. *P value <0.05 compared with baseline.

Fig. 4.

Respiratory rate (RR) at baseline (BL), midway (mid), and at the end of 14 min of MM (MM), control intervention, and controlled breathing (CB). *P value <0.05 for MM vs. control intervention at that time point. †ANOVA F-test was significant for a difference between MM vs. control interventions.

Fig. 5.

Change in MSNA from baseline to minute 14 during control intervention, MM, and CB. *P value <0.05 compared with control intervention.