Obstructive sleep apnoea, insulin resistance and adipocytokines

Abstract

SummaryObstructive sleep apnoea (OSA) is associated with multiple cardiometabolic abnormalities. Obesity is considered a major risk factor for the development of OSA, and it is also an established risk factor for insulin resistance and other cardiometabolic disorders. The enigma remains whether OSA has any causal role in the adverse metabolic profile, independent of or beyond that due to obesity. Sleep apnoeas and hypopnoeas result directly in intermittent hypoxaemia and cerebral arousals, both of which may evoke a cascade of downstream biologic responses in various body tissues and cells. Adipose tissue is a major source of adipocytokines many of which play important roles in the regulation of various metabolic functions. It is hypothesized that OSA may, through its unique pathophysiology, affect metabolic function through modulation of production or action of adipocytokines. This review focuses on insulin resistance, glucose metabolism and relevant adipocytokines in the context of OSA.

The Bidirectional Relationship Between Obstructive Sleep Apnea and Metabolic Disease

“…For example, fasting can mitigate some cardiovascular consequences of IH, including the activation of glycogen synthase in the myocardium ( 127 ). Additionally, treatment with a lipolysis inhibitor ameliorates hyperglycemia and glucose intolerance induced by IH in mice ( 81 ), highlighting an important role for the adipose tissue and lipolysis in many of the downstream consequences of IH and perhaps OSA ( 77 , 128 ). Taken together, it is likely that circulating and fasting glucose is increased by OSA and that elevated glucose before the theoretical onset of OSA is likely to exacerbate the cardiometabolic outcomes of OSA.…”

Epidemiological and pathophysiological evidence supporting links between obstructive sleep apnoea and Type 2 diabetes mellitus

“…test; and the short insulin tolerance test for insulin sensitivity. (15) The plethora of outcome measures has challenged the grounds for making consistent comparisons across studies. Nevertheless, multiple studies have suggested a relationship between OSA and DM, which is most likely bidirectional.…”

Effects of small interfering RNA targeting TLR4 on expressions of adipocytokines in obstructive sleep apnea hyponea syndrome with hypertension in a rat model

“…Plasma levels of ADN released by adipose tissues were obviously higher in OSA patients and OSA played an essential role in stimulating endocrine functions of adipocytokines (Wolk et al, ). The modulation of OSAS in producing ADN brought about hypoadiponectinaemia and further caused worse cardiometabolic disorders (Lam et al, ). An increase in the serum leptin levels, which is a hormone produced by subcutaneous fat, caused increasing severity of OSAS, and associates with high morbidity of cardiovascular diseases (Ip, Lam, Ho, Tsang, & Lam, ; Tokuda, Sando, Matsui, Koike, & Yokoyama, ).…”