From adrenarche to aging of adrenal zona reticularis: precocious female adrenopause onset

Abstract

Objective: Adaptive changes in DHEA and sulfated-DHEA (DHEAS) production from adrenal zona reticularis (ZR) have been observed in normal and pathological conditions. Here we used three different cohorts to assess timing differences in DHEAS blood level changes and characterize the relationship between early blood DHEAS reduction and cell number changes in women ZR.

Materials and methods: DHEAS plasma samples (n = 463) were analyzed in 166 healthy prepubertal girls before pubarche (<9 years) and 324 serum samples from 268 adult females (31.9-83.8 years) without conditions affecting steroidogenesis. Guided by DHEAS blood levels reduction rate, we selected the age range for ZR cell counting using DHEA/DHEAS and phosphatase and tensin homolog (PTEN), tumor suppressor and cell stress marker, immunostaining, and hematoxylin stained nuclei of 14 post-mortem adrenal glands.

Results: We confirmed that overweight girls exhibited higher and earlier DHEAS levels and no difference was found compared with the average European and South American girls with a similar body mass index (BMI). Adrenopause onset threshold (AOT) defined as DHEAS blood levels <2040 nmol/L was identified in >35% of the females >40 years old and associated with significantly reduced ZR cell number (based on PTEN and hematoxylin signals). ZR cell loss may in part account for lower DHEA/DHEAS expression, but most cells remain alive with lower DHEA/DHEAS biosynthesis.

Conclusion: The timely relation between significant reduction of blood DHEAS levels and decreased ZR cell number at the beginning of the 40s suggests that adrenopause is an additional burden for a significant number of middle-aged women, and may become an emergent problem associated with further sex steroids reduction during the menopausal transition.

Keywords: DHEA-S; DHEAS; PTEN; adrenarche; adrenopause; dehydroepiandrosterone; female; phosphatase and tensin homolog; sulfated-dehydroepiandrosterone.

Figure 1

Scatter plot of DHEAS values. DHEAS levels are shown in 166 girls from 3 up to 8 years of age (463 samples in total). Groups (underweight, normal and overweight) were compared by trendlines using quadratic fit.

Figure 2

(A) Scatter plot of serum DHEAS values in adult women. Groups were compared by trendlines using quadratic fit. The horizontal dashed line was placed on level 2040 nmol/L. (B) Box plot associating DHEAS levels and age in women and summarizing the minimum, first quartile, median, third quartile, and maximum values.

Figure 3

DHEA/DHEAS immunostaining-positive cells at age 16 years (A and E), and at the age with a significant reduction in DHEAS blood level, at 43 years (B and F). Scale bar 100 µm (A and B) and 10 µm (E and F). ZR, zona reticularis; ZF, zona fasciculata; ZG, zona glomerulosa. Nuclei are shown in blue (hematoxylin counterstained), DHEA/DHEAS are stained brown. PTEN immunostaining-positive nuclei (brown) at peak DHEAS blood level at 19 years (C and G), and at the age with the most intense DHEAS blood level reduction, at 43 years (D and H). Scale bar 100 µm (C and D) and10 µm (G and H). The cytoplasmic PTEN signal was either not detectable in most cells or was a very weak signal in few cells (red arrow-heads). ZR, zona reticularis; ZF, zona fasciculata; ZG, zona glomerulosa.