Neurotrophin levels at admission did not change significantly upon alcohol deprivation and were positively correlated with the BMI and LDL levels

BACKGROUND The neurotrophins brain-derived neurotrophic factor (BDNF) and neurotrophic factor 3 (NT3) could play a role in addictive behavior. Interactions between BDNF and dopamine transmission influence the alcohol intake. It has been hypothesized that extensive alcohol consumption leads to diminished circulating BDNF levels and impaired BDNF-mediated protective mechanisms. What is more, alcohol dependency causes changes in lipid metabolism which in turn may influence the neurotrophin system. METHODS In this study, we tested the hypothesis that alcohol withdrawal increases the serum levels of BDNF in alcoholic patients and investigated correlations between serum BDNF and NT3 and alcohol in breath as well as with the body-mass-index (BMI), lipoprotein profiles and lifestyle factors in 110 male in-patients diagnosed with alcohol addiction on the first day after admission and at discharge. RESULTS The intoxication level (alcohol in breath at admission) was significantly correlated with liver enzymes and BDNF concentrations (R = .28; p = .004). Patients with positive breath-alcohol test at admission had about 9 times higher NT3 levels and higher liver enzyme concentration levels than nonintoxicated subjects. Alcohol intoxicated patients with pathological aspartate aminase (ASAT) levels had even higher NT3 level (F = 5.41; p = .022). The concentration of NT3 was positively associated with the (BMI) (admission R = .36; p = .004; discharge R = .33; p = .001), and the obese patients had 3 to 5 times higher NT3 concentration than the others. Low-density lipoprotein (LDL) concentration levels were found to positively correlate with NT3 concentration levels (admission R = .025; p = .015 discharge R = .24; p = .23). CONCLUSION Other than expected, the levels of NT3 and to a lesser extent BDNF levels, were found to be significantly increased in acute alcohol abuse. Alcohol deprivation did not significantly change the serum neurotrophin levels at admission. NT3 levels were positively correlated with the BMI and LDL levels. Because of expected difference between genders, we recommend investigating these correlations further in patients of both genders.