Preliminary Study On The Relationship Of The Anthropometric Characteristics And The Change Of NPY With Abnormal Lipid Metabolism In Patients With OSAS

Objective: Obstructive Sleep Apnea Syndrome(OSAS)has a close relationship with obesity.This study was designed to explore the possible role of body parameters of OSAS patients in predicting the OSAS severity.And the changes of neuropeptide Y and leptin levels in blood serum in patients with OSAS were determined.The secreted characteristics of these two hormones in patients with OSAS were studied and their role in the development of obesity in OSAS was explored.Methods: In the first part of the study,patients with OSAS were divided into mild OSAS group and severe OSAS group according to apnea-hyponea index(AHI).The height,weight,waist circumference and hip circumference were measured.We calculated the BMI,WHR,BAI,and BAIw.The body characteristics were evaluated in OSAS patients with varying degrees of obesity to determine which of the body parameters or indicators were statistically correlated to the severity of OSAS.In the second part,the patients with OSAS and the healthy subjects were included in the study.The content and rhythm of serum neuropeptide Y,cortisol,norepinephrine and melatonin were determined at 8:00,16:00 and 00:00.The serum level of leptin was determined at 8:00.Results: In the first part,30 OSAS patients were enrolled,including 14 patients with mild OSAS and 16 patients with severe OSAS.Eight healthy subjects were entered into the control group.There was a significant difference between each group(P <0.05)in BMI,waist circumference,hip circumference,WHR,BAI and BAIw.WHR was an independent risk factor in predicting OSAS or severe OSAS.But hip circumference was important in WHR when predicting OSAS,while waist circumference was important in WHR when predicting severe OSAS.None of BMI,WHR,BAI or BAIw had statistic preference to predict OSAS severity.In the second part,the content and rhythm of serum neuropeptide Y,cortisol,norepinephrine and melatonin were determined at 8:00,16:00 and 00:00.The serum level of leptin was determined at 8:00.Conclusion: Waist circumference,hip circumference,waist-to-hip ratio,BMI,BAI,BAIw can be used as an index to evaluate body size of patients with OSAS.Simple measurements of waist circumference and hip circumference can be used to evaluate the severity of OSAS.OSAS induced an increased circadian rhythm of NPY secretion leading to proliferation and metabolic disorder of white adipose tissue around the subcutaneous and visceral organs and accumulation of fat.Subsequently,excessive increase in overload excessive load of subcutaneous adipose tissue resulted in abnormal visceral fat deposition that changed the visceral adipose tissue endocrine status,leading to excessive leptin secretion.Excessive secretion of leptin into the CNS inhibited the central NPY synthesis and secretion,resulting in loss of NPY secretion rhythm.NPY and leptin may be important molecules in OSAS patients with obesity and fat ectopic deposition.