Obstructive sleep apnoea syndrome, plasma adiponectin levels, and insulin resistance.
ABSTRACT To investigate whether sleep-disordered breathing and/or plasma adiponectin levels are associated with insulin resistance independent of obesity or fat distribution in obstructive sleep apnoea syndrome (OSAS).
Cross-sectional clinical study.
Two-hundred and thirteen Japanese patients with OSAS aged 27-80 years were divided into three groups: 30 with mild OSAS [apnoea-hypopnoea index (AHI) = 10.3 +/- 0.9 episodes/h, minimum oxygen saturation (min SpO2) = 87.3 +/- 0.9%], 98 with moderate OSAS (AHI = 28.9 +/- 0.6 episodes/h, min SpO2 = 82.1 +/- 0.7%), and 85 with severe OSAS (AHI = 68.1 +/- 2.8 episodes/h, min SpO2 = 72.3 +/- 1.6%). Twenty-one patients undergoing diabetic treatments (two mild, nine moderate and 10 severe) were excluded from the assessment of insulin resistance and plasma adiponectin measurements.
Fat distribution [evaluated according to visceral (V) and subcutaneous (S) fat areas using computed tomography scanning at the umbilical level], blood pressure, metabolic parameters and hormones including insulin and adiponectin were measured. After full polysomnography, venous blood was collected between 0600 and 0700 h.
Severe OSAS patients were more hypertensive than mild and moderate OSAS. Fasting plasma glucose (FPG) and fasting plasma insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels were all higher in severe OSAS than mild and moderate OSAS patients. HOMA-IR was correlated not only with obesity [body mass index (BMI), V and S areas] but also with apnoea (AHI, min SpO2 and desaturation time). Additionally, HOMA-IR was correlated positively with haemoglobin (Hb)A1c, systolic (SBP) and diastolic blood pressure (DBP), triglycerides and free fatty acids (FFA), and negatively with high density lipoprotein (HDL)-cholesterol, suggesting that insulin resistance is a key component of the metabolic syndrome in OSAS. Plasma adiponectin levels were not different between mild, moderate and severe OSAS groups. Plasma adiponectin levels were correlated with HOMA-IR and V area, but not AHI or min SpO2. Stepwise multiple regression analysis, however, revealed that BMI, AHI and plasma adiponectin were independently associated with HOMA-IR.
Sleep-disordered breathing was associated with insulin resistance independent of obesity. Although plasma adiponectin was also an independent determinant of HOMA-IR in OSAS patients, plasma adiponectin was more closely related to obesity than to sleep apnoea. Although treatment of sleep-disordered breathing with nasal continuous positive airway pressure reportedly improves insulin sensitivity, our findings suggest that treatment of obesity is also essential in ameliorating insulin resistance at least through increased plasma adiponectin levels in OSAS.
- SourceAvailable from: Fabio Lanfranco[Show abstract] [Hide abstract]
ABSTRACT: Obstructive sleep apnea syndrome (OSAS) is a serious, prevalent condition that has significant morbidity and mortality when untreated. It is strongly associated with obesity and is characterized by changes in the serum levels or secretory patterns of several hormones. Obese patients with OSAS show a reduction of both spontaneous and stimulated growth hormone (GH) secretion coupled to reduced insulin-like growth factor-I (IGF-I) concentrations and impaired peripheral sensitivity to GH. Hypoxemia and chronic sleep fragmentation could affect the sleep-entrained prolactin (PRL) rhythm. A disrupted Hypothalamus-Pituitary-Adrenal (HPA) axis activity has been described in OSAS. Some derangement in Thyroid-Stimulating Hormone (TSH) secretion has been demonstrated by some authors, whereas a normal thyroid activity has been described by others. Changes of gonadal axis are common in patients with OSAS, who frequently show a hypogonadotropic hypogonadism. Altogether, hormonal abnormalities may be considered as adaptive changes which indicate how a local upper airway dysfunction induces systemic consequences. The understanding of the complex interactions between hormones and OSAS may allow a multi-disciplinary approach to obese patients with this disturbance and lead to an effective management that improves quality of life and prevents associated morbidity or death.International Journal of Endocrinology 02/2010; 2010(1687-8337):474518. DOI:10.1155/2010/474518 · 1.52 Impact Factor
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ABSTRACT: Metabolic syndrome (MS), the commonly used term for the clustering of obesity, insulin resistance, hypertension, and dyslipidemia, affects millions of people worldwide, and is associated with an increased risk of cardiovascular disease and type 2 diabetes. Recently, it has been suggested that obstructive sleep apnea (OSA), an increasingly prevalent condition, may contribute to the development of MS and diabetes. Despite substantial evidence from both clinical and population studies to suggest an independent link between OSA and metabolic abnormalities, the issue still remains controversial. Obesity, particularly visceral obesity, is an important factor in the assessment of adverse metabolic outcome in OSA. Further prospective and interventional studies, with adequate sample sizes and longer follow-up, rigorous control for adiposity, and, ideally, randomization and control for any therapeutic intervention, are clearly needed to address the direction of causality. There are multiple mechanistic pathways involved in the interaction between OSA, obesity, and metabolic derangements. Chronic intermittent hypoxia and sleep fragmentation with sleep loss in OSA are likely key triggers that initiate or contribute to the sustenance of inflammation as a prominent phenomenon, but their complex interplay remains to be elucidated. In summary, OSA may represent a novel risk factor for MS and diabetes, and thus clinicians should be encouraged to systematically evaluate the presence of metabolic abnormalities in OSA and vice versa.Proceedings of the American Thoracic Society 03/2008; 5(2):207-17. DOI:10.1513/pats.200708-139MG
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ABSTRACT: The purpose of this systematic review is to evaluate the diagnostic value of biological markers (exhaled breath condensate, blood, salivary and urinary) in the diagnosis of OSA in comparison to the gold standard of nocturnal PSG.Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine 10/2014; DOI:10.5664/jcsm.4358 · 2.83 Impact Factor