Description
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by plaques, tangles, and neuronal cell loss. In the earliest stages of AD, tangles develop in brain structures associated with olfactory processing. Previous research has found that along with the current diagnostic measures, the additional use of olfactory measures can increase the correct classification rate for AD. The cause of AD is unknown, however, there are notable risk factors associated with the onset and development of AD. Currently, the strongest genetic risk factor associated with AD is the presence of an _4 allele of the Apolipoprotein E gene. Other risk factors associated with AD include age, low education, family history, Down syndrome, mild cognitive impairment, head trauma, and cardiovascular health factors, such as high blood pressure, high cholesterol, heart disease, stroke, and diabetes. Increases in adipose tissue, especially in areas around the abdomen, have been linked to increases in cardiovascular health problems. Epidemiological studies suggest a connection between maintaining a healthy weight, exercising, and eating healthier choices and the age of onset of AD such that healthier lifestyles may prolong AD onset by up to 5 years. Therefore, it is important to understand the influence and role of obesity in AD. Olfactory event-related potential latencies were recorded during odor memory encoding and retrieval tasks. Latencies were examined at the N1, P2, N2, and P3 ERP components and the midline electrode sites Fz, Cz, and Pz were analyzed as they produce the cleanest OERP waveform. I investigated correlations between different measures of obesity including body mass index (BMI), waist circumference, and waist to hip ratios and olfactory processing speed for healthy individuals who are genetically at risk for AD (ApoE _4+) (n= 30) and for those not genetically at risk (ApoE _4-) (n= 30). Bivariate correlation analyses revealed significant positive correlations between measures of obesity and ERP latencies during odor retrieval for the genetically at risk group (ApoE _4+). It is important to note that these significant linear relationships occurred for young, middle, and older aged participants. However, the exclusion of older participants from analyses strengthened previous relationships, therefore highlighting the importance of adiposity on brain integrity as early as young and middle age. These findings provide useful information about the negative effects of adiposity, especially among those genetically at risk for AD
