Plasma amyloid β protein 42 in non-demented persons aged 75 years:: Effects of concomitant medication and medial temporal lobe atrophy

Plasma amyloid beta(AP42) levels increase with age and are elevated in some patients during the early stages of Alzheimer's disease (AD). Although plasma AP42 is not useful for diagnosis of AD, it might be a biological risk factor. In the elderly population a considerable variety of concomitant medication is used for the treatment of various disorders. How this co-medication might influence AP42 levels is still to be investigated. Through the Vienna Transdanube Aging study (VITA), the authors measured cross-sectional AP42 plasma levels during the initial examination of 526 individuals aged 75 years without dementia. The medication considered included: treatment with calcium channel blockers, digitalis, anticoagulants, antihistamines, ergotamine, histamine H-2 receptor antagonists, bronchodilators, pentoxyfilline, neuroleptics, insulin, oral antidiabetics, L-dopa, benzodiazepines, oestrogen, Gingko biloba, vitamins, piracetam, non-steroidal anti-inflammatory drugs (NSAIDs), and statins. Of the study population aged 75 years, 90% were users of some of the above-mentioned medication. Depending on their medial temporal lobe atrophy (NITA), users of insulin showed significantly increased levels of AP42, while users of gingko biloba for at least 2 years of drug intake had significantly decreased AP42 plasma levels, independent of their NITA. Users of NSAIDs showed a non-significant trend to reduced AP42 plasma levels, while users of biguanides showed an increase in AP42 plasma levels. In the multiple regression analysis considering possible interactions between various medications statin users showed a significant decrease of A beta 42; insulin users had again significantly higher and long-term gingko biloba users lower plasma A beta 42 levels. Persons with a low degree of NITA had significantly increased A 42 plasma levels. Considering the increase of A beta 42 plasma levels, as a risk factor for AD, any changes induced by medication by long-term use in the peripheral and possibly also in the central compartment, could be of clinical relevance. (c) 2005 Elsevier Inc. All rights reserved.