Obesity itself does not influence BDNF serum levels in adults

In European countries more than 50% of the population are overweight, 30% with obesity. In Poland overweight was present in 41% of men and 28.7% of women (obesity 15.7% and 19.9%). It was examined whether obesity affects serum levels of brain-derived neurotrophic factor (BDNF) and interleukin-6 (IL-6), which may lead to the consequences of obesity, such as type 2 diabetes, hypertension, and finally the metabolic syndrome. We aimed to examine whether obesity affects the serum levels of BDNF and IL-6.

The study involved 144 people aged 45 to 86 years, 80 subjects with diagnosed obesity and 64 with normal body weight, ≤ 65 years old (n = 45) and > 65 years old (n = 99). All patients underwent tests of glucose, total cholesterol, HDL, LDL, triglycerides levels, using routine laboratory methods. A test of the concentration of IL-6 and BDNF was carried out. The declared level of physical activity (gymnastics, cycling or walking) was considered.

It was shown that in women ≤ 65 years old, obesity was associated with higher levels of interleukin-6. When the test group, divided into the above categories, was analyzed for the diagnosis of hypertension, heart failure or diabetes mellitus, no statistically significant differences in the investigated parameters were detected. The concentration of brain-derived neurotrophic factor did not differ in the investigated subjects, regardless of sex, age, obesity, or the declared physical activity.

The concentration of interleukin-6 in younger people, including those with normal body weight, correlated with total cholesterol and triglyceride levels, and it was significantly higher in obese women compared to those with normal body weight.