Acute Effects of Gabapentin in Sleep Parameters and Hormonal Release During Sleep in Older Men

Phase 4

Terminated

Brief Summary: The primary objective of this study is to evaluate the effects of gabapentin in sleep polysomnography parameters and in nocturnal secretion of endogenous hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG) and somatotropic axes hormones and basal IGF-1 in older men.

Detailed Description: The influence of sleep variables on muscle protein anabolism is little studied, but data on the effects of slow-wave sleep and the syndrome of obstructive sleep apnea on the hypothalamic-pituitary axis indicate that interventions in the sleep structure and disorders impact on the age-related muscle loss. Thus, we propose to assess the acute effects of a drug potentially capable of increasing slow wave sleep, and consequently growth hormone release during sleep, on the physiological release of growth hormone, testosterone and IGF-1 during the night in older healthy men.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Basal Apnea-Hypopnea index (aHI)>=15
Restless Legs Syndrome Symptons
BMI less than 18.5 kg/m2 or greater than 30 kg/m2
Less than 30 min. of regular physical activity (at least walking inside home, etc.)
Plasma albumin below 3.5 mg/dL
Psychoactive drugs use
Drugs with muscle anabolic potential
Current treatment for obesity or weight gain
Enteral or parenteral feeding
Inability to walk without assistance,
Loss of independence in any activity of daily living
Nocturia above 2 episodes
Smoking more than 2 cigarettes per day
Alcoholism (more than 2 doses a day)
Prior epilepsy diagnosis
Clinically evident atherosclerotic disease
Dementia
Depression
Rheumatic diseases
Cancer
Diabetes (poorly controlled, HbA1C > 7,0, requirement of insulin)
Thyroid dysfunction without treatment
Advanced stages in COPD, HF, liver or renal failure

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	A single dose of placebo with exactly the same characteristics of the active drug at bedtime.
Gabapentin	Gabapentin	A single dose of Gabapentin 300mg at bedtime.

Primary Outcome Measures

Name	Time	Method
Growth Hormone Secretion	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime.	Every 20 minutes after admission to the laboratory, blood samples (2.5 mL) for GH measurement will be collected (between 20:00 - or 2 hours before lights off - and 06:00).
IGF-1	Immediately after the sleep night in that gabapentin or placebo dose were given at bedtime.	It will be included in the analysis of the last sample collected for GH, testosterone and cortisol measurements at 06:00.

Secondary Outcome Measures

Name	Time	Method
Total testosterone	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime.	Every 20 minutes after admission to the laboratory, blood samples (2.5 mL) for free and total testosterone measurements will be collected (between 20:00 - or 2 hours before lights off - and 06:00).
Apnea-Hypopnea Index during sleep	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime. a single gabapentin or placebo dose at bedtime.	Sedative drugs may increase asymptomatic airway collapsability during sleep mainly in older individuals
Slow Wave Sleep - Stage N3	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime.	Full sleep night polysomnographic recording.
Free testosterone	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime.	Every 20 minutes after admission to the laboratory, blood samples (2.5 mL) for free and total testosterone measurements will be collected (between 20:00 - or 2 hours before lights off - and 06:00).
Cortisol	During only one sleep night immediately after a single gabapentin or placebo dose at bedtime.	Every 20 minutes after admission to the laboratory, blood samples (2.5 mL) for cortisol measurement will be collected (between 20:00 - or 2 hours before lights off - and 06:00).