Design and Patients: Morbidly obese patients (n = 41) were divided into those whose apneahypoapnea index (AHI) was more or less than the median value and on the presence of OSA [OSA and no OSA (nOSA) groups]. We studied the antioxidant function of HDL and measured serum paraoxonase 1 (PON1) activity, TNFα, and intercellular adhesion molecule 1 (ICAM-1) levels in these patients. In a subset of 19 patients, we immunostained gluteal sc adipose tissue (SAT) for TNFα, macrophages, and measured adipocyte size.
Results: HDL lipid peroxide levels were higher and serum PON1 activity was lower in the high AHI group vs the low AHI group (P<.05 and P<.0001, respectively) and in the OSA group vs the nOSA group (P=.005andP<.05, respectively). SerumTNFα andICAM-1 levelsandTNFα immunostaining in SAT increased with the severity of OSA. Serum PON1 activity was inversely correlated with AHI (r=-0.41, P<.03) in the OSA group. TNFα expression in SAT directly correlated with AHI (r=0.53, P < .03) in the subset of 19 patients from whom a biopsy was obtained.
Context: Obstructive sleep apnea (OSA) complicates morbid obesity and is associated with increased cardiovascular disease incidence. An increase in the circulating markers of chronic inflammation and dysfunctional high-density lipoprotein (HDL) occur in severe obesity. Copyright
Objective: The objective of the study was to establish whether the effects of obesity on inflammation and HDL dysfunction are more marked when complicated by OSA.
Conclusion: Increased serum TNFα, ICAM-1, and TNFα expression in SAT provide a mechanistic basis for enhanced inflammation in patients with OSA. Decreased serum PON1 activity, impaired HDL antioxidant function, and increased adipose tissue inflammation in these patients could be a mechanism for HDL and endothelial dysfunction.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry
- Biochemistry, medical