Altered sleep patterns in patients with non-functional GHRH receptor

Area of Science:

• Endocrinology
• Sleep Medicine
• Genetics

Background:

• Growth hormone-releasing hormone (GHRH) influences sleep, with hypnotic effects on non-rapid eye movement (NREM) sleep.
• Growth hormone (GH) stimulates REM sleep.
• Growth hormone deficiency (GHD) is often associated with sleep disturbances, fatigue, and reduced quality of life (QoL).

Purpose of the Study:

• To investigate sleep quality in adult subjects with isolated GHD (IGHD) resulting from GHRH resistance.
• To determine if GHRH receptor gene mutations impact sleep architecture and subjective sleep quality.

Main Methods:

• A cross-sectional study involving 21 adult IGHD patients and 21 matched controls.
• Objective sleep assessment using polygraphic recordings (awake, NREM stages N1, N2, N3, REM).
• Subjective sleep evaluation via validated questionnaires (Pittsburgh Sleep Quality Index, Insomnia Severity Index, Epworth Sleepiness Scale).

Main Results:

• IGHD subjects demonstrated reduced sleep efficiency, total sleep time, and duration of N2 and REM sleep.
• Increased duration and percentage of N1 stage, wake, and wake-time after sleep onset were observed in IGHD subjects.
• No significant differences were found in N3 sleep duration or subjective sleep quality scores between groups.

Conclusions:

• Patients with IGHD due to GHRH resistance exhibit objective impairments in sleep quality, characterized by alterations in NREM and REM sleep.
• Despite objective sleep changes, IGHD subjects reported no subjective sleep consequences or reduced QoL.
• GHRH resistance appears to play a more significant role than GHD itself in determining sleep quality in these individuals.