Stressed baby boys may snore as adults

Stress as a baby can lead to a respiratory disorder associated with snoring in adult males, according to new research published today [7 March] in Experimental Physiology, providing new insight into why men suffer more from sleep-disordered breathing than women.

The study showed that stressful experience in early life, such as separation from the mother, can disrupt the development of male babies’ hormone regulation systems. One potential consequence of this can be respiratory problems in adulthood.

Dr Richard Kinkead, who led the study at the Centre de Recherche du CHU de Québec, Canada, said:

“Over the past decade, our laboratory has established that neonatal stress has persistent and sex-specific effects on blood pressure and respiration, with consequences that persist well into adulthood.

“We use rats because much like pre-term infants their brains are immature at birth and highly sensitive to stress. Moreover, there are similarities between their cardio-respiratory system and ours, so this study provides real insights into the conditions that cause respiratory disorders in the human population.

“The different results in males and females in our previous studies suggested that sex hormones were contributing to the emergence of respiratory issues. Stress in early life did not affect long-term, baseline hormone levels. But when oxygen levels were lowered, there was a significant increase in the levels of testosterone circulating in the blood of stressed rats, but not in the controls. Though not well understood, this abnormal regulation of testosterone release seems to contribute to the respiratory problems we observed.”

In this study, on male rats, those removed from their mothers in early life had a greater hypoxic ventilatory response (HVR) – breathing difficulties when in reduced oxygen atmosphere, as at high altitude or when the respiratory system relaxes during sleep – than those in a control group left undisturbed with their mothers.

Surgical ablation of the testes to reduce the testosterone in the body proved to significantly reduce HVR.

Researchers found an increased number of androgen receptors in the brainstem of the stressed rats, which is the likely reason why these rats were more sensitive to the presence and withdrawal of testosterone.

Sleep-disordered breathing is a significant problem and is commonly associated with other pathologies such as hypertension and depression. This research advances our understanding of the processes around the condition and potential treatments.

ENDS

Notes for Editors

1.Research paper: Fournier S, Gulemetova R, Joseph V and Kinkead R. (2014) Testosterone potentiates the hypoxic ventilatory response of adult male rats subjected to neonatal stress. Experimental Physiology. [http://ep.physoc.org/content/early/2014/03/05/expphysiol.2013.077073.abstract]

 

2.Experimental Physiology publishes high quality, original, physiological research papers that give novel insights into fundamental homeostatic and adaptive responses in health and papers that further our knowledge of pathophysiological mechanisms in diseases. http://ep.physoc.org

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