Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index.

Dementias of old age, in particular Alzheimer's disease (AD), pose a growing threat to the longevity and quality of life of individuals as well as whole societies world-wide. The risk factors are both genetic and environmental (life-style) and there is an overlap with similar factors predisposing to cardiovascular diseases (CVD). Using a case-control genetic approach, we have identified a SNP (rs10507391) in ALOX5 gene, previously associated with an increased risk of stroke, as a novel genetic risk factor for AD. ALOX5 gene encodes a 5'-lipoxygenase (5'-LO) activating protein (FLAP), a crucial component of the arachidonic acid/leukotriene inflammatory cascade. A-allele of rs4769874 polymorphism increases the risk of AD 1.41-fold (p<0.0001), while AA genotype does so 1.79-fold (p<0.0001). In addition, GG genotype of rs4769874 polymorphism is associated with a modest increase in body mass index (BMI). We discuss potential biochemical mechanisms linking the SNP to AD and suggest possible preventive pharmacotherapies some of which are based on commonly available natural products. Finally, we set the newly identified AD risk factors into a broader context of similar CVD risk factors to generate a more comprehensive picture of interacting genetics and life-style habits potentially leading to the deteriorating mental health in the old age.

Diabetes, hypertension and stroke - does Alzheimer protect you?

OBJECTIVE: The aim of our current research project is to further evaluate the role of risk factors in the pathogenesis of Alzheimer's disease; these include genetic variations, environmental factors and lifestyle issues. METHODS: We have been conducting an association study on 373 patients with Alzheimer's disease and 286 unrelated control individuals. The occurrence and the age of onset of diabetes and cardiovascular diseases were evaluated in both groups. Apolipoprotein E genotype was analyzed in all subjects by PCR method. RESULTS: We report that, in Czech population carrying ApoE4 allele increases risk of Alzheimer's disease 2.1-fold and genotype E4E4 increases the risk 8.4-fold. We have also identified a significant association between ApoE4 allele, Alzheimer's disease and hypertension. Hypertensive subjects with the ApoE4 allele have 1.5-fold greater risk of Alzheimer's disease. Thus, hypertension together with ApoE4 allele translates into 1.5-fold higher risk of AD. The most intriguing original finding in the present study is that Alzheimer's disease patients have significantly later onset of diabetes, hypertension and stroke in comparison with control subjects. This effect was not influenced by ApoE genotype. The diabetes appeared in AD patients on average more than 10 years later than in the control subjects (p<0.0001), hypertension was diagnosed 14 years later in AD patients (p<0.00001) and stroke occurred on average 6 years later (p<0.005), compared to the control group. CONCLUSIONS: Overall, in addition to the above novel findings, our study expands the data base on risk factors that could be used in near future when testing for the genetic risk of Alzheimer's disease.