Neurotransmitter enhancement therapy with acetylcholinesterase inhibitors (AChEIs) is a clinically proven approach for patients with Alzheimer's disease (AD). Donepezil is one of the three currently approved AChEIs for treating AD symptoms delaying the decline in cognitive function. In addition to cholinergic hypofunction, there are several factors in AD pathogenesis. For example, adipocytokines released from adipose tissue are also thought to play a role in the progress of dementia. Adipokines, i.e., leptin and adiponectin, are involved in the modulation of certain cognitive functions in the brain. The goal of our study was to elucidate effects of donepezil therapy on the serum levels of certain adipokines, such as leptin and adiponectin in AD patients. Clinically diagnosed mild-to-moderate AD patients (n = 26) were involved in this open-labeled, single-center, prospective self-control study. ApoE polymorphism, serum adiponectin, leptin, LDL, HDL, triglyceride levels, and BMI were determined before and at 12 and 24 weeks intervals of donepezil treatment, respectively. Twenty-four weeks of donepezil treatment induced a linear decrease of serum leptin levels (p = 0.013) and a linear elevation of serum adiponectin levels (p = 0.007). BMI (p < 0.001) and abdominal circumference (p = 0.017) were significantly lower at 24 weeks as compared to control values. None of the other examined metabolic parameters were changed during the treatment period. This previously unrecognized serum adipokine regulating potential of donepezil may be relevant in its therapeutic, disease modifying effect in AD by transferring protective (by increasing serum adiponectin levels) and detrimental (by decreasing serum leptin levels) effects onto the neurodegenerative process at the same time.
Keywords: Acetylcholinesterase inhibitor; Alzheimer's disease; adipokine; adiponectin; apolipoprotein E; body weight; dementia; donepezil; leptin.