Figure 1. Midlife and Late-Life Plasma Aβ Distributions and Scatterplots Concurrently and Cross-Temporally.

Graphs display histograms of plasma amyloid-β (Aβ) distributions (picograms per milliliter or ratio) at midlife and late life. Change scores (midlife − late life; picograms per milliliter) reflect increases in Aβ₄₂ and Aβ₄₀ from midlife to late life. Individual observations are plotted with a lowess smoother and kernel density plots representing quartiles 1, 2 (median), and 3 of the data. Forty-six observations with Aβ₄₂ or Aβ₄₀ values exceeding 70 or 500 pg/mL, respectively, were removed for enhanced visualization. Ratio distributions in panel A have been log₂ transformed to approximate normality. (A) Late-life and midlife plasma Aβ₄₂:Aβ₄₀; correlation 0.487. (B) Late-life and midlife plasma Aβ₄₂ (picograms per milliliter); correlation 0.486. (C) Late-life and midlife plasma Aβ₄₀ (picograms per milliliter); correlation 0.313. (D) Midlife plasma Aβ₄₂ (picograms per milliliter) and Aβ₄₀ (picograms per milliliter); correlation 0.612. (E) Late-life plasma Aβ₄₂ (picograms per milliliter) and Aβ₄₀ (picograms per milliliter); correlation 0.470. (F) Change in plasma Aβ₄₂ (picograms per milliliter) and plasma Aβ₄₀ (picograms per milliliter); correlation 0.612.