Resistin is closely related to systemic inflammation in obstructive sleep apnea

Obstructive sleep apnea (OSA) is closely related to systemic inflammation. Resistin is an adipocyte-derived cytokine (adipokine) that may link obesity with inflammation.

We aimed to investigate whether incremental changes in OSA severity, from normal to severe, primarily affect the levels of resistin and other adipokines.

Serum levels of resistin, interleukin-6 (IL-6) and leptin were examined in 31 men with OSA and 10 men without OSA, matched for age, body mass index (BMI) and several metabolic profiles. In 11 of the 31 men with OSA, these mediators were reexamined after 3 months of nasal continuous airway pressure (nCPAP) therapy.

Levels of resistin and IL-6 were simultaneously elevated in men with OSA compared with those in men without OSA (p < 0.05), while levels of leptin did not differ. The resistin and IL-6 levels tended to increase with increasing disease severity (p < 0.05), which was based on the apnea-hypopnea index (AHI). The average oxyhemoglobin saturation during sleep (p < 0.01) and IL-6 (p < 0.05) emerged as significant determinants of resistin, even after adjustments for age, BMI, leptin levels and metabolic risk factors. After nCPAP therapy, the elevated levels of resistin and IL-6 decreased, reaching almost baseline levels of controls. Before treatment, AHI correlated positively with the reduction rate in resistin (p < 0.05).

In OSA patients, resistin production can be enhanced by hypoxic stress during sleep, possibly mediating systemic inflammatory processes. nCPAP therapy may play a beneficial role in the control of resistin production.