Hypothalamic-pituitary-adrenal (HPA) axis functioning in relation to body fat distribution
Femke Rutters1, Arie G Nieuwenhuizen, Sofie G T Lemmens
1Department of Human Biology, Maastricht University, Maastricht, The Netherlands. F.Rutters@hb.unimaas.nl
Clinical Endocrinology
|September 23, 2009
Summary
Disturbances in the hypothalamic-pituitary-adrenal (HPA) axis and its feedback mechanisms are linked to increased visceral fat accumulation. This study explores HPA axis function in relation to body fat distribution.
Area of Science:
- Endocrinology
- Metabolic Health
- Human Physiology
Background:
- The hypothalamic-pituitary-adrenal (HPA) axis regulates the body's response to stress.
- Body fat distribution, particularly visceral fat, is associated with metabolic and cardiovascular risks.
- Understanding the interplay between HPA axis function and fat distribution is crucial for metabolic health.
Purpose of the Study:
- To investigate the relationship between hypothalamic-pituitary-adrenal (HPA) axis functioning and HPA feedback mechanisms.
- To correlate these HPA axis parameters with body fat distribution in individuals ranging from normal weight to obese.
- To explore potential sex differences in these relationships.
Main Methods:
- Study included 91 men and 103 women aged 18-45 years with Body Mass Index (BMI) from 19-35 kg/m(2).
- Assessed body composition via hydrodensitometry and deuterium dilution.
- Measured cortisol variability (5-h concentrations), HPA axis feedback (dexamethasone suppression test), and HPA axis response to a high-intensity exercise challenge.
Main Results:
- In men, higher fat mass index (FMI) correlated inversely with 5-h cortisol exposure and HPA axis negative feedback.
- In women, waist-to-hip ratio (WHR) showed inverse relationships with 5-h cortisol exposure and HPA axis negative feedback.
- HPA axis functioning under challenge was inversely related to waist circumference in men and WHR in women, suggesting a link to visceral fat accumulation.
Conclusions:
- Dysregulation of the HPA axis, both under basal and challenged conditions, is associated with increased visceral fat.
- These findings highlight the significant role of HPA axis function in the pathophysiology of obesity and fat distribution.
Related Concept Videos
01:37Hypothalamic-Pituitary Axis
The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.
01:02Hypodermis
The hypodermis (the subcutaneous layer or superficial fascia) is present directly below the dermis. It connects the skin to the underlying fascia (fibrous tissue) of the bones and muscles. It is not strictly a part of the skin, although the border between the hypodermis and dermis can be difficult to distinguish. The hypodermis consists of well-vascularized, loose, areolar connective tissue and adipose tissue, which functions as a mode of fat storage and provides insulation and cushioning for...
01:24Physiological Foundation of Stress
Stress triggers a coordinated physiological response involving the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. This dual activation ensures that the body is prepared for both immediate and prolonged stress management. The process begins with the perception of a stressor. This initial phase activates the SNS, leading to the rapid release of adrenaline (epinephrine) from the adrenal glands.
Role of the Sympathetic Nervous System
Adrenaline triggers the...
Role of the Sympathetic Nervous System
Adrenaline triggers the...
01:19Cushing Syndrome II: Pathophysiology
Cortisol production is normally governed by the hypothalamic–pituitary–adrenal (HPA) axis, which maintains hormonal balance through tightly regulated feedback mechanisms. Disruption of this regulatory system is central to the development of Cushing syndrome, whether the excess cortisol originates from external medications or internal pathology. Persistent cortisol elevation alters metabolism, immune function, and endocrine signaling, producing the characteristic clinical features of the...
01:31Hormones of the Adrenal Glands
Adrenal hormones play a pivotal role in maintaining the body's electrolyte balance and orchestrating responses to stress, showcasing the intricate functions of the adrenal cortex and medulla.
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone...
The adrenal cortex, a powerhouse of hormone synthesis, generates over two dozen corticosteroid hormones. The zona glomerulosa produces mineralocorticoids, exemplified by aldosterone, influencing the electrolyte composition of body fluids. The synthesis of glucocorticoids such as cortisol and corticosterone...
01:27Major Hormones and Their Functions
Hormones, the biochemical messengers produced by endocrine glands, are pivotal in regulating bodily functions and maintaining homeostasis. Each hormone's balance is crucial; imbalances can lead to significant physiological disruptions. Major hormones include oxytocin, cortisol, epinephrine, estrogen, testosterone, thyroxine, growth hormone, insulin, and glucagon.
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.