Neuroendocrine Response Following a Thoracic Spinal Manipulation in Healthy Men

Abstract

Study Design Controlled laboratory study. Background Spinal manipulation (SM) can trigger a cascade of responses involving multiple systems, including the sympathetic nervous system and the endocrine system, specifically, the hypothalamic-pituitary axis. However, no manual therapy study has investigated the neuroendocrine response to SM (ie, sympathetic nervous system-hypothalamic-pituitary axis) in the same trial. Objective To determine short-term changes in sympathetic nervous system activity, heart rate variability, and endocrine activity (cortisol, testosterone, and testosterone-cortisol [T/C] ratio) following a thoracic SM. Methods Twenty-four healthy men aged between 18 and 45 years were randomized into 2 groups: thoracic SM (n = 12) and sham (n = 12). Outcome measures were salivary cortisol (micrograms per deciliter), salivary testosterone (picograms per milliliter), T/C ratio, heart rate variability, and changes in oxyhemoglobin concentration of the right calf muscle (micromoles per liter). Measurements were done before and at 5 minutes, 30 minutes, and approximately 6 hours after intervention. Results A statistically significant group-by-time interaction was noted for T/C ratio (P<.05) and salivary cortisol (P<.01) concentrations. Significant between-group differences were noted for salivary cortisol concentration at 5 minutes (mean difference, 0.35; 95% confidence interval: 0.12, 0.6; interaction: P<.01) and for T/C ratio at 6 hours postintervention (mean difference, -0.09; 95% confidence interval: -0.16, -0.04; P = .02). However, SM did not differentially alter oxyhemoglobin, testosterone, or heart rate variability relative to responses in the sham group. Conclusion Thoracic SM resulted in an immediate decrease in salivary cortisol concentration and reduced T/C ratio 6 hours after intervention. A pattern of immediate sympathetic excitation was also observed in the SM group. J Orthop Sports Phys Ther 2017;47(9):617-627. Epub 13 Jul 2017. doi:10.2519/jospt.2017.7348.

The acute effects of joint manipulative techniques on markers of autonomic nervous system activity: a systematic review and meta-analysis of randomized sham-controlled trials

“…1). Of these, 16 deal with mobilizations (oscillatory technique) [35–50], 1 with an atypical mobilization technique [51], 5 with sustained natural apophyseal glides (SNAGs) / mobilization with movement [52–56], and 7 with high velocity low amplitude manipulation [57–63]. The experimental interventions were undertaken in various parts of the spine but also in the extremities in two studies [38, 52] and the effects were reported in relation to skin conductance ( N = 15), heart rate ( N = 11), skin temperature ( N = 11), blood pressure ( N = 7), HRV ( N = 5), respiratory rate ( N = 3), skin blood flow ( N = 3), biochemical markers ( N = 2), pupil diameter ( N = 1), and oxy-hemoglobin concentration ( N = 1).…”

“…Low-certainty evidence (Table 3 P, Q) suggests that spinal manipulation may have no acute effect on cardiac autonomic activity, as there was no effect on various HRV components immediately after the intervention. There was no effect on the spectral power of the normalized HF component (mean difference 1.16, 95% CI -4.86 to 7.18, I 2 = 0%, p = 0.71, 3 studies [57–59]), no effect on the spectral power of the normalized LF component (mean difference 2.84, 95% CI -3.47 to 9.14, I 2 = 0%, p = 0.38, 3 studies [57–59]), and no effect on the LF / HF ratio (mean Difference − 0.06, 95% CI -0.34 to 0.22, I 2 = 0%, p = 0.67, 4 studies [57–59, 63]). Sampath et al [63] also reported no effect on the LF / HF ratio 30 min after the intervention.…”

“…Very low-certainty evidence (Table 3 O, P) suggests that spinal manipulation has no acute effect on muscle sympathetic nerve activity, as there was no effect on the oxy-hemoglobin concentration measured on a calf muscle immediately, 5 min, and 30 min after the intervention in 1/1 study [63].…”

The effect of a single spinal manipulation on cardiovascular autonomic activity and the relationship to pressure pain threshold: a randomized, cross-over, sham-controlled trial

“…not during the very immediate period after the interventions), since we first measured the sensitivity to experimentally induced pain. This is different from the sham-controlled trials included in the previous review which measured HRV within the 5 min [34,[50][51][52] after the interventions. Our results at short term (i.e.…”

“…Our results at short term (i.e. 30-40 min) are also in accordance with another sham-controlled trial that reported no RRi intervals between normal beats; Log logarithm with base 10; HF high frequency; HF normalized unit: HF/(HF + LF) x 100; LF low frequency; RMSSD root mean square of the successive differences between normal heartbeats; SDNN standard deviation of the inter beat interval of normal sinus beats; SBP systolic blood pressure; DBP diastolic blood pressure; MBP mean blood pressure effect on the LF/HF ratio 30 min after the intervention [52]. However, a recent sham-controlled trial [21] reported a statistically significant effect of a thoracic HVLA manipulation on a time domain index of HRV (increase of RMSSD) within the 60 s following the intervention.…”