Circulating cell free DNA response to exhaustive exercise in average trained men with type I diabetes mellitus

Abstract

It is believed that neutrophils extracellular traps (NETs) formation is responsible for the increase in cf DNA after exercise. Since T1DM is accompanied by enhanced NETs generation, we compared exercise-induced increase in cf DNA in 14 men with T1DM and 11 healthy controls and analyzed its association with exercise load. Subjects performed a treadmill run to exhaustion at speed corresponding to 70% of their personal VO2max. Blood was collected before and just after exercise for determination of plasma cf nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Exercise resulted in the increase in median cf n-DNA from 3.9 ng/mL to 21.0 ng/mL in T1DM group and from 3.3 ng/mL to 28.9 ng/mL in controls. Median exercise-induced increment (∆) in cf n-DNA did not differ significantly in both groups (17.8 ng/mL vs. 22.1 ng/mL, p = 0.23), but this variable correlated with run distance (r = 0.66), Δ neutrophils (r = 0.86), Δ creatinine (r = 0.65) and Δ creatine kinase (r = 0.77) only in controls. Pre- and post-exercise cf mt-DNA were not significantly different within and between groups. These suggest low usefulness of Δ cf n-DNA as a marker of exercise intensity in T1DM men.

Figure 1

Circulating cell free nuclear DNA (cf n-DNA) response to exhaustive treadmill exercise at speed corresponding to 70% of personal VO2max in male volunteers with T1DM (n = 14) and healthy control group (n = 11). Δ exercise induced increment. Results are expressed as mean, standard deviation, and (median). Exercise resulted in significant increase in cf n-DNA in both groups. No significant differences were noted between groups. The points (corresponding to values before and after the exercise) joined with lines represent individual results in both studied groups.

Figure 2

Circulating cell free mitochondrial DNA (cf mt-DNA) before and after exhaustive treadmill exercise at speed corresponding to 70% of personal VO2max in male volunteers with T1DM (n = 14) and healthy control group (n = 11). Δ exercise induced increment. Results are expressed as mean, standard deviation, and (median). No significant differences were found within and between groups. The points (corresponding to values before and after the exercise) joined with lines represent individual results in both studied groups.