Neu SC, et al. - A scrutiny was conducted of the consequence of sex and apolipoprotein E (APOE) genotype on the risks of developing mild cognitive impairment (MCI) and Alzheimer's disease (AD). In opposition to the long-standing opinions, men and women with the APOE ε3/ε4 genotype exhibited approximately the same odds of developing AD from age 55 to 85 years. However, women reported an increased risk at younger ages.

Methods

• This research encompassed twenty-seven independent research studies in the Global Alzheimer’s Association Interactive Network, with data on nearly 58000 subjects.
• It enrolled non-Hispanic white individuals with clinical diagnostic and APOE genotype data.
• Homogeneous data sets were cumulated in the case-control analyses, and logistic regression models estimated the risks.
• The primay outcome included estimation of the age-adjusted odds ratios (ORs) and 95% confidence intervals for developing MCI and AD, for men and women across APOE genotypes.

Results

• The age of the enrollees were betwen 55 and 85 years.
• A majority of the candidates were white, and for many individuals, racial/ethnic information was either not collected or not known.
• Men (OR, 3.09; 95% CI, 2.79-3.42) and women (OR, 3.31; CI, 3.03-3.61) with the APOE ε3/ε4 genotype from ages 55 to 85 years did not display a change in AD risk.
• Nevertheless, women reported a greater risk compared with men between the ages of 65 and 75 years (women, OR, 4.37; 95% CI, 3.82-5.00; men, OR, 3.14; 95% CI, 2.68-3.67; P = .002).
• Men with APOE ε3/ε4 demonstrated an increased risk of AD compared with men with APOE ε3/ε3. The APOE ε2/ε3 genotype conferred a protective effect on women (OR, 0.51; 95% CI, 0.43-0.61) decreasing their risk of AD more (P value=.01) than men (OR, 0.71; 95% CI, 0.60-0.85).
• No variation was illustrated between men with APOE ε3/ε4 (OR, 1.55; 95% CI, 1.36-1.76) and women (OR, 1.60; 95% CI, 1.43-1.81) in their risk of developing MCI between the ages of 55 and 85 years.
• However, women presented with an increased risk between 55 and 70 years (women, OR, 1.43; 95% CI, 1.19-1.73; men, OR, 1.07; 95% CI, 0.87-1.30; P=.05).
• No substantial changes were noted between men and women in their risks for converting from MCI to AD between the ages of 55 and 85 years.
• Individuals with APOE ε4/ε4 exhibited increased risks vs individuals with ε3/ ε4, but there were no marked differences between men and women with ε4/ ε4.