Background: Diabetic neuropathy (DN) is a very frequent microvascular complication
of type 2 diabetes mellitus (T2DM). Obesity and physical inactivity are well-known
risk factors for T2DM. Fibroblast growth factor 21 (FGF21) is a liver-secreted hormone
with several beneficial effects on obesity-related metabolic disorders. We aimed to
investigate the effect of short-term physical activity on the levels of FGF21, and
its correlation with the severity of peripheral sensory polyneuropathy in T2DM patients.
Methods: Thirty patients with DN were enrolled in the study, compared to age- and
gender-matched controls. We conducted a six-week aerobic training program, which meant
treadmill and cycle ergometers three times a week. Anthropometric and laboratory parameters
were measured for each patient before and after intervention. Serum levels of FGF21,
TNF-alpha, irisin, leptin and adiponectin were measured by ELISA. The sensory perception
threshold (CPT) was quantitatively measured using Neurometer?. Results: We found significant
decreases in BMI, waist circumference, HbA1c and TNF-alpha levels. From baseline to
six-week follow-up, FGF21 levels were significantly increased in DN patients. Significant
negative correlations were shown between the changes in FGF21 levels and BMI, between
changes in FGF21 and the improvement of CPT values, and between the changes in FGF21
and TNF-alpha levels. There was no difference in irisin, adiponectin and leptin levels
in DN patients after aerobic training program. Conclusion: The physical activity may
increase the level of FGF21 in T2DM patients with neuropathy. Our results highlight
the importance of regular physical activity in the treatment of diabetic neuropathy.
