Changes in pro-inflammatory markers and leucine concentrations in response to Nordic Walking training combined with vitamin D supplementation in elderly women

Abstract

Mechanisms underpinning age-related decreases in muscle strength and muscle mass relate to chronic inflammation. Physical activity induces an anti-inflammatory effect, but it is modulated by additional factors. We hypothesized that vitamin D, which has also anti-inflammatory activity will modify adaptation to exercise and reduce inflammation in elderly women. Twenty-seven women aged 67 ± 8 years were included and divided into groups with baseline vitamin D concentration more than 20 ng mL^-1 (MVD) and less than 20 ng mL^-1 (LVD). Both groups performed 1 h Nordic Walking (NW) training combined with vitamin D supplementation for 12 weeks. Serum concentrations of inflammation markers, branched amino acids, vitamin D, muscle strength and balance were assessed at the baseline and three days after intervention. The training caused the significant decrease in concentration of pro-inflammatory proteins HMGB1 (30 ± 156%; 90% CI) and IL-6 (-10 ± 66%; 90% CI) in MVD group. This effects in group MVD were moderate, indicating vitamin D as one of the modifiers of these exercise-induced changes. Rise of myokine irisin induced by exercise correlated inversely with HMGB1 and the correlation was more pronounced at the baseline as well as after training among MVD participants. Although the intervention caused the leucine level to rise, a comparison of the recorded response between groups and the adjusted effect indicated that the effect was 20% lower in the LVD group. Overall the applied training program was effective in reducing HMGB1 concentration. This drop was accompanied by the rise of myokine irisin and better uptake of leucine among women with higher baseline vitamin D.

Keywords: Aging; Branched chain amino acids; High-Mobility Group Box 1 (HMGB1).

Fig. 1

Correlation between irisin and HMGB1 at the baseline and in response to 12 weeks Nordic Walking training in elderly women: a group LVD with baseline blood vitamin D level less than 20 ng mL⁻¹, b group MVD with baseline blood vitamin D level more than 20 ng mL⁻¹

Fig. 2

Changes in concentration of vitamin D at the baseline (I) and after whole intervention (II) in booth groups: LVD group with baseline blood vitamin D level less than 20 ng mL^−1, MVD group with baseline blood vitamin D level more than 20 ng mL⁻¹