Conclusions
Results suggest that MBSR may protect against declines in the sensitivity of immune cells to the anti-inflammatory effects of glucocorticoids among at-risk lonely older adults and show value in studying this biological mechanism in future trials.
Methods
Lonely older adults (65-85 years; n = 190) were randomly assigned to an 8-week Mindfulness-Based Stress Reduction (MBSR) or a matched Health Enhancement Program (HEP). Whole blood drawn before and after the intervention and at 3-month follow-up was incubated with endotoxin and varying concentrations of dexamethasone, and interleukin-6 production was assessed using enzyme-linked immunosorbent assay. GCR was assessed as the concentration of dexamethasone required to decrease the stimulated interleukin-6 response by 50% (half maximal inhibitory concentration), with higher concentrations indicating greater GCR. Mixed-effects linear models tested time (pre, post, follow-up) by condition (MBSR versus HEP) effects.
Objective
Mindfulness interventions have been effective for improving a range of health outcomes; however, pathways underlying these effects remain unclear. Inflammatory processes may play a role, possibly through increased resistance of immune cells to the anti-inflammatory effects of glucocorticoids (i.e., glucocorticoid resistance, or GCR). Here, we conducted an initial examination of whether mindfulness training mitigates GCR among lonely older adults.
Results
There was no overall time by condition effect on GCR across all time points. However, a significant time by condition effect was observed from preintervention to postintervention (d = 0.29), such that MBSR buffered increases in GCR observed in the HEP group. Although MBSR showed small, nonsignificant reductions in GCR from preintervention to 3-month follow-up, group differences were not maintained at the 3-month follow-up (d = 0.10). Conclusions: Results suggest that MBSR may protect against declines in the sensitivity of immune cells to the anti-inflammatory effects of glucocorticoids among at-risk lonely older adults and show value in studying this biological mechanism in future trials.
Trial registration
Clinical Trials identifier NCT02888600.