Mitigating cellular inflammation in older adults: a randomized controlled trial of Tai Chi Chih

Abstract

Objectives: To evaluate the effects of a behavioral intervention, Tai Chi Chih (TCC) on circulating markers of inflammation in older adults.

Design: A prospective, randomized, controlled trial with allocation to two arms, TCC and health education (HE), 16 weeks of intervention administration, and 9 weeks follow-up.

Participants: A total of 83 healthy older adults, aged 59 to 86 years.

Measurements: The primary endpoint was circulating levels of interleukin 6 (IL-6). Secondary outcomes were circulating levels of C-reactive protein, soluble IL-1 receptor antagonist, soluble IL-6 receptor, soluble intercellular adhesion molecule, and IL-18. Severity of depressive symptoms, sleep quality, and physical activity was also assessed over the treatment trial.

Results: Among those older adults with high levels of IL-6 at entry, a trend for a treatment group by time interaction was found (F[1,70] = 3.48, p = 0.07), in which TCC produced a drop of IL-6 levels comparable to those found in TCC and HE subgroups who had low levels of IL-6 at entry (t72's = 0.80, 1.63, p's >0.10), whereas IL-6 in HE remained higher than the TCC and HE subgroups with low entry IL-6 (t72 = 2.47, p = 0.02; t72 = 1.71, p = 0.09). Decreases in depressive symptoms in the two treatment groups correlated with decreases of IL-6 (r = 0.28, p <0.05). None of the other cellular markers of inflammation changed in TCC versus HE.

Conclusion: TCC can be considered a useful behavioral intervention to reduce circulating levels of IL-6 in older adults who show elevated levels of this inflammatory marker and are at risk for inflammation-related morbidity.

Trial registration: ClinicalTrials.gov NCT00118885.

Conflict of interest statement

Conflict of interest statement

Dr. Irwin, the corresponding author, has had full access to all the data in the study and has final responsibility for the decision to submit for publication. Drs. Irwin and Olmstead declare that they have no conflicts of interest.

Figures

Figure 1

Participant flow and distribution of subjects in study

Figure 2

Effects of Tai Chi Chih vs. health education on circulating levels of interleukin-6 over 25 weeks. TCC is stratified by entry levels of IL-6 into high quartile (λ) and lower three quartiles (σ), and health education is stratified by entry levels of IL-6 into high quartile (μ) and lower three quartiles (∇). The shaded area indicates the duration of the intervention from baseline to week 16.