Are you Yoshiyuki Aoki?

Claim your profile

Publications (2)5.54 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We aimed to assess whether obstructive sleep apnoea syndrome (OSAS) affects plasma IGF-1 and dehydroepiandrosterone sulphate (DHEA-S) levels in men, factors implicated in the development of age-related metabolic disorders. We conducted a cross-sectional and longitudinal clinical study. We measured plasma IGF-1 and DHEA-S levels in 191 non-drug-treated Japanese men (34 primary snorers (PS), 88 patients with mild-to-moderate OSAS and 69 patients severe OSAS ). Plasma IGF-1 and DHEA-S were negatively correlated with age. Plasma IGF-1 was also negatively correlated with plasma glucose, HOMA-IR and systolic blood pressure and apnoea parameters such as the apnoea-hypopnea index, minimum oxygen saturation and slow-wave sleep (SWS) time. Plasma DHEA-S was associated with plasma glucose, HbA1c and free fatty acid and was negatively correlated with SWS time. To eliminate the influence of age, PS, patients with mild-to-moderate OSAS and severe OSAS were divided into three groups by age: young (<40 years), middle-aged (40-59 years) and elderly (≥ 60 years). Patients with severe OSAS aged <40 or <60 years had lower plasma IGF-1 or DHEA-S levels, respectively, than did the corresponding snorers and mild-to-moderate OSAS groups. Continuous positive airway pressure therapy for generally 16-18 months increased plasma IGF-1 levels in patients with severe OSAS aged <40 years (n = 18). Plasma DHEA-S levels were increased in patients with severe OSAS aged <60 years, whose DHEA-S level was below the mean value for that age (n = 23/41). Severe OSAS could reduce plasma IGF-1 and DHEA-S levels in younger, but not elderly Japanese men, which is potentially associated with the development of metabolic abnormalities.
    Clinical Endocrinology 09/2011; 76(4):593-601. · 3.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Obstructive sleep apnea syndrome (OSAS) is related to the increased prevalence of cardiovascular disease and metabolic syndrome (MS). A novel adipokine, retinol binding protein-4 (RBP4), was reported to be associated with insulin resistance and the prevalence of type 2 diabetes. To examine whether plasma RBP4 is associated with insulin resistance and MS development in OSAS, we measured plasma RBP4 levels in 181 Japanese men (24 healthy controls and 40 mild, 64 moderate, and 53 severe OSAS) of whom 26 had mild glucose intolerance with HbA1c < or = 6.0%. After a full polysomnography, blood was collected between 06:00 and 07:00 AM. Plasma RBP4 levels in moderate/severe OSAS patients were higher than in control subjects. Plasma RBP4 was not correlated with apnea variables, HOMA-IR, or blood pressure. However, it was positively correlated with visceral fat areas and plasma triglyceride levels. The prevalence of MS was higher in severe OSAS patients than in mild/moderate OSAS and control subjects. Plasma RBP4 was higher in OSAS patients with MS than in those without MS. This study indicates that plasma RBP4 is associated with dyslipidemia, but not with insulin resistance, glucose intolerance, or hypertension in patients with OSAS. Visceral obesity may play key roles in increasing the plasma RBP4 level and MS development in OSAS.
    Hormone and Metabolic Research 11/2008; 41(3):221-6. · 2.15 Impact Factor