Obstructive sleep apnea and effects of continuous positive airway pressure on triglyceride-rich lipoprotein metabolism

Abstract

This study aimed to explore lipoprotein metabolism in obstructive sleep apnea (OSA) and the effects of continuous positive airway pressure (CPAP). We studied 15 men with severe OSA [apnea-hypopnea index (AHI) ≥30 events/hour] and 12 age-, BMI-, and waist circumference-matched volunteers without OSA (AHI <5 events/hour). Carotid intima-media thickness (CIMT) was determined by a blind examiner. After 12 h fasting, a triglyceride-rich chylomicron-like emulsion, labeled with [C]cholesteryl oleate and [H]triolein, was injected intravenously followed by blood sample collection at preestablished times. Fractional clearance rate (FCR) of the radiolabeled lipids was estimated by compartmental analysis of radioisotope decay curves. Compared with controls, patients with OSA showed a significant delay in both cholesteryl ester FCR (0.0126 ± 0.0187 vs. 0.0015 ± 0.0025 min; = 0.0313) and triglycerides FCR (0.0334 ± 0.0390 vs. 0.0051 ± 0.0074 min; = 0.0001). CIMT was higher in the OSA group: 620 ± 17 vs. 725 ± 29 µm; = 0.004. Cholesteryl ester FCRs were inversely related to total sleep time <90% ( = -0.463; = 0.029) and CIMT ( = -0.601; = 0.022). The triglyceride FCR was inversely correlated with AHI ( = -0.537; = 0.04). In a subgroup of patients treated with CPAP for 3 months (n = 7), triglyceride FCR increased 5-fold ( = 0.025), but the cholesteryl ester FCR was unchanged. In conclusion, severe OSA decreased lipolysis of triglyceride-rich lipoproteins and delayed removal of remnants. CPAP treatment may be effective to restore the lipolysis rates.

Adipose tissue as a key player in obstructive sleep apnoea

“…A recent study in OSA patients corroborates the previous results from rodents exposed to IH, showing a decreased lipolysis of triglyceride-rich lipoproteins in patients with severe OSA [66]. Furthermore, delayed triglyceride-rich lipoproteins clearance through adipose tissue lipoprotein lipase inhibition were associated with increased carotid intima-media thickness [66]. The majority of observational studies support a link between OSA and dyslipidaemia [64], while in a meta-regression analysis, apnoea-hypopnoea index had a significant effect on low density lipoprotein and triglycerides [67].…”

“…As previously described in rodents, IH results in an increase in metabolic dyslipidaemia in patients with OSA [65] favoured by upregulated triglycerides and phospholipids biosynthesis, and inhibited triglyceride uptake in the liver. A recent study in OSA patients corroborates the previous results from rodents exposed to IH, showing a decreased lipolysis of triglyceride-rich lipoproteins in patients with severe OSA [66]. Furthermore, delayed triglyceride-rich lipoproteins clearance through adipose tissue lipoprotein lipase inhibition were associated with increased carotid intima-media thickness [66].…”

Analysis of Metabolites Changes on Obstructive Sleep Apnea Patients After Multilevel Sleep Surgery

“…Furthermore, the same group has recently shown that people with severe OSA exhibited delayed lipoprotein remnants removal as well as decreased lipolysis of TG rich particles. Both processes were positively correlated with the severity of IH and were enhanced by CPAP treatment [52]. Our data are also pointing in the same direction and highlighting the beneficial impact of MLS in the treatment of OSA.…”

Targeted Metabolomics Analysis on Obstructive Sleep Apnea Patients after Multilevel Sleep Surgery

“…Furthermore, the same group has recently shown that people with severe OSA exhibited delayed lipoprotein remnants removal, as well as decreased lipolysis of TG-rich particles. Both processes were positively correlated with the severity of IH and were enhanced by CPAP treatment [ 55 ]. Our data also point in the same direction and highlight the beneficial impact of MLS in the treatment of OSA.…”