The effect of increased ambulatory activity on markers of chronic low-grade inflammation: Evidence from the PREPARE programme randomized controlled trial

Aims To investigate whether an exercise intervention programme, with or without pedometer use, is effective at reducing chronic low-grade inflammation in those with impaired glucose tolerance.Methods Using baseline and 12 month data from the Pre-diabetes Risk Education and Physical Activity Recommendation and Encouragement (PREPARE) programme randomized controlled trial, we investigated whether the pedometer or the standard version of the PREPARE programme is associated with reduced chronic low-grade inflammation. Outcomes included interleukin-6, C-reactive protein, fasting and 2 h post-challenge glucose values and objectively measured ambulatory activity.Results Sevety-four participants (31% female; mean age, 65 years; body mass index, 29.3 ± 4.8 kg/m²) were included, of which 26 were in the control group and 24 were in each intervention group. At 12 months there was an increase in ambulatory activity of 1351 and 1849 steps/day in the standard and pedometer group, respectively, compared with control conditions; however, there was no significant change in markers of chronic low-grade inflammation. Across the pooled study sample, change in ambulatory activity was significantly correlated with change in interleukin-6 (r = -0.32, P = 0.01) after adjustment for group, age, sex, ethnicity, aspirin and statin medication, baseline body mass index and change in body mass index. Change in interleukin-6 was also significantly correlated with change in 2 h glucose after adjustment for the same variables (r = 0.26, P = 0.03).Conclusions This study failed to show reductions in markers of chronic low-grade inflammation following an intervention that promoted modest increases in ambulatory activity; however, across the study sample, increased ambulatory activity was associated with reduced interleukin-6, independent of obesity.