Cholesterol delivery to the adrenal glands estimated by adrenal venous sampling: An in vivo model to determine the contribution of circulating lipoproteins to steroidogenesis in humans.
Level 4 - case-series / case-control
Physiological cross-sectional sampling study in a small clinical cohort
PubMed 28461157 · doi:10.1016/j.jacl.2017.03.018
What was done
Blood samples were drawn from both adrenal veins and the inferior vena cava (IVC) in 23 patients with primary aldosteronism undergoing adrenal venous sampling (AVS). High-density lipoprotein cholesterol (HDL-C) and lipoprotein particle concentrations (HDL-P and LDL-P) were quantified using nuclear magnetic resonance spectroscopy. Apolipoprotein A-I (apoA-I) and apolipoprotein B (apoB) concentrations were measured by immunoturbidimetry to compare adrenal venous levels to systemic (IVC) levels in the whole cohort and in a subgroup of 13 patients with aldosterone-producing adenomas (APA).
What was found
Plasma HDL-C, HDL-P, and LDL-P were not significantly lower in adrenal venous samples compared to IVC samples (HDL-C: P = .59; HDL-P: P = .06; LDL-P: P = .93). ApoB was significantly lower in adrenal venous plasma than in IVC (P = .026 overall; P < .05 for right adrenal vein). In the 13 APA patients, apoB was also significantly lower in the APA adrenal vein versus IVC (P = .045), and LDL-P trended lower (P = .065). ApoA-I concentrations were not significantly lower in adrenal venous plasma compared to IVC in either the overall group (P = .20) or the APA subgroup (P = .075). Absolute concentration values and effect sizes were not reported in the abstract.
Why it matters
This study provides direct in vivo human evidence that the adrenal gland takes up circulating LDL-derived apoB particles for steroidogenesis, demonstrating that adrenal venous sampling can serve as a clinical model for studying organ-specific lipoprotein metabolism.
Limits
The study is limited by a small sample size (n = 23 overall, n = 13 APA) and a population restricted to patients with primary aldosteronism, which may not generalize to normal adrenal physiology. Absolute concentrations, confidence intervals, and organ blood flow rates were not reported in the abstract.
Cited by
- supports The adrenal glands and gonads utilize cholesterol delivered by LDL to synthesize steroid hormones.