What hormone is most likely increased in a patient with chronic fatigue, weight gain, and sleep deprivation due to a varied work schedule, leading to increased appetite and metabolism changes?

Sleep Deprivation and Ghrelin Elevation

The most likely explanation for this patient's chronic fatigue and weight gain is an increase in ghrelin (option b), as sleep deprivation consistently elevates this orexigenic hormone, which stimulates appetite and contributes to weight gain independent of BMI.

Hormonal Changes in Sleep Deprivation

Ghrelin Elevation

• Short sleep duration (3-7 hours) is directly associated with elevated ghrelin levels, with a predicted 14.9% higher ghrelin for 5 hours versus 8 hours of sleep, independent of BMI 1.
• Ghrelin is the only known orexigenic (appetite-stimulating) hormone and increases hunger and food intake 2.
• The elevation in ghrelin with sleep restriction occurs regardless of body composition and is proportional to the degree of sleep curtailment 1.

Leptin Suppression (Not Elevation)

• Sleep deprivation causes decreased leptin levels, not increased 1.
• A predicted 15.5% lower leptin occurs with habitual sleep of 5 hours versus 8 hours 1.
• This makes option "c" (leptin increase) incorrect, as leptin actually decreases with sleep deprivation.

Mechanism of Weight Gain

Appetite Dysregulation

• The combination of elevated ghrelin and suppressed leptin creates a hormonal milieu that increases appetite and promotes positive energy balance 1.
• These hormonal changes are likely to increase appetite, explaining the increased BMI observed with short sleep duration 1.
• Ghrelin stimulates food intake by acting on hypothalamic centers, the hindbrain, and the mesolimbic reward system 2.

Clinical Context

• In Western societies where chronic sleep restriction is common and food is widely available, changes in appetite regulatory hormones with sleep curtailment contribute to obesity 1.
• This patient's military work schedule with variable shifts and only 3-7 hours of sleep per 24-hour period creates the exact conditions for ghrelin elevation and subsequent weight gain.

Why Other Options Are Incorrect

Glucose (Option a)

• While sleep deprivation can affect glucose metabolism, glucose elevation is not the primary driver of the appetite changes and weight gain described 1.
• The hormonal appetite dysregulation (ghrelin/leptin) is the more direct mechanism.

Growth Hormone (Option d)

• Growth hormone is secreted by the pituitary and has anabolic effects on skeletal muscle 3.
• Growth hormone is not primarily associated with appetite stimulation or the weight gain pattern seen with sleep deprivation 3.
• Growth hormone deficiency, rather than excess, would be more consistent with chronic fatigue states.

Clinical Implications

The U-shaped curvilinear association between sleep duration and BMI demonstrates that in persons sleeping less than 8 hours, increased BMI is proportional to decreased sleep 1. This patient's 3-7 hour sleep pattern places him squarely in the range where ghrelin elevation drives appetite and weight gain, making ghrelin (option b) the correct answer.