Does sleep apnea contribute to peripheral edema?

From the Guidelines

Sleep apnea is a significant contributor to peripheral edema, primarily due to its effects on heart function and fluid retention. The relationship between sleep apnea and peripheral edema can be explained by several mechanisms:

• Increased pressure in the chest: Repeated episodes of airway obstruction create negative pressure in the chest, which can impair blood return to the heart, as discussed in the context of obstructive sleep apnoea syndrome (OSAS) treatment options 1.
• Right-sided heart strain: This pressure change and intermittent low oxygen levels can lead to right-sided heart dysfunction over time, which is a known consequence of untreated OSAS 1.
• Hormonal changes: Sleep apnea disrupts normal hormone balance, particularly affecting antidiuretic hormone (ADH) and atrial natriuretic peptide (ANP), which regulate fluid balance.
• Increased aldosterone: The body may produce more aldosterone in response to perceived low oxygen, leading to sodium and water retention.
• Sedentary lifestyle: People with sleep apnea often feel fatigued, leading to less physical activity and poorer circulation in the legs. Although the provided study 1 focuses on non-CPAP therapies in obstructive sleep apnoea, it highlights the importance of treating sleep apnea to reduce cardiovascular morbidities, which can indirectly contribute to peripheral edema. Treating sleep apnea, typically with continuous positive airway pressure (CPAP) therapy, is essential to manage peripheral edema, and additional measures such as elevating the legs, wearing compression stockings, and increasing physical activity can also help alleviate the condition.

From the Research

Relationship Between Sleep Apnea and Peripheral Edema

• Sleep apnea has been associated with an increased risk of peripheral edema, particularly in patients with fluid-retaining states such as congestive heart failure and end-stage renal disease 2.
• The pathophysiology of sleep apnea involves fluid shift, where fluid retained in the legs during the day shifts rostrally while recumbent, leading to edema of upper airways 2.
• Studies have shown that patients with sleep apnea are more likely to have peripheral edema, with one study finding that 41% of patients with obstructive sleep apnea had pretibial edema 3.
• The presence of sleep apnea has been found to be a significant predictor of peripheral edema, with an odds ratio of 3.068 in one study 4.

Mechanisms Underlying the Relationship

• The mechanism underlying the relationship between sleep apnea and peripheral edema is thought to involve the redistribution of fluid during sleep, leading to increased pressure in the upper airways and subsequent edema 2.
• Pulmonary hypertension is also a common finding in patients with sleep apnea and peripheral edema, and is thought to contribute to the development of edema 3.
• Inflammation may also play a role in the relationship between sleep apnea and peripheral edema, with studies showing that sleep apnea can induce systemic inflammation 5.

Clinical Implications

• The association between sleep apnea and peripheral edema has important clinical implications, particularly in patients with idiopathic leg edema, where sleep apnea may be an underlying cause 4.
• Routine sleep apnea assessment is recommended in patients with idiopathic bilateral leg edema 4.
• Treatment of sleep apnea may also be beneficial in reducing the risk of peripheral edema, particularly in patients with fluid-retaining states 2.