The figure is from Dementia and Alzheimer Disease Incidence

The figure is from: Dementia and Alzheimer Disease Incidence: A Prospective Cohort Study (JAMA, 2002, Vol59, No. 11). Read the caption to select which criteria for causality that the figure satisfies. Fill in the criteria in the space provided. Do this task for all five figures. Age and the incidence of Alzheimer disease for persons with an apolipoprotein E sum4 allele compared with persons without an apolipoprotein E sum4 allele. Person-years were calculated by dividing the number of cases by the number of person-years of exposure within 5-year intervals starting at the age of 65 years (these are multiplied by 1000 to get rates per 1000 person-years. Question Asked: What causes Dementia & Alzheimer? Could APOE e4 Allele be a risk factor?

Solution

I Answer:

The correct answer is \"Strength of Association\". The graph is showing the strength of relation of APOe4 allele with the disease.

II Answer:

Dementia is a syndrome; Alzheimer\'s disease is a type of dementia. Dementia occurs when certain brain cells are damaged. The damage may be due to an injury, prolonged drug use, HIV infection, stroke etc.

Alzheimer\'s disease is a type of dementia. In this plaques are formed in certain regions of the brain. As a result, those regions of the brain are impaired and become useless. Slowly cell connections are lost; at last these brain cells die.

The main genetic determinant of Alzheimer\'s disease is apolipoprotein E. When an injury occurs in the brain, then the cholesterol carrier, apolipoprotein is responsible to repair the same. Researches have shown that individuals having allele e4 are at greater risk of this disease in comparison to those having e3 and e2. So, your answer is yes, APOE allele e4 is a risk factor. The diagram is clearly showing the same.