A Study On Target Organ Damage In Patients With Obstructive Sleep Apnea-hypopnea Syndrome

BackgroundClinic-based studies suggested that obstructive sleep apnea-hypopnea syndrome(OSAHS) was associated with insulin resistance(IR), which had been quite well recognized as fundamental and leading causes of major health issues such as impaired glucose metabolism, cardiovascular diseases, and stroke. However, the molecular mechanism of how OSAHS caused insulin resistance remained to be rarely investigated.ObjectiveThe purpose of the study was to investigate whether OSAHS affected serum levels of white adipose tissue hormones, focusing on adiponectin, tumor necrosis factor-α(TNF-α), and interleukin-6(IL-6), which might help to explain OSAHS-associated target organ damage.MethodsFollowing polysomnographic examination, 80 adult male habitual snorers were divided into 4 groups: 20 with simple snorers, 20 with mild OSAHS, 20 with moderate OSAHS, and 20 with severe OSAHS. There was no significant difference in age and body mass index (BMI) among the 4 groups. The homeostasis model assessment of insulin resistance (HOMA-IR) was used to calculate insulin resistance. The serum levels of adiponectin, TNF-α,and IL-6 were measured by enzyme linked immunosorbent assay(ELISA). HOMA-IR and serum levels of white adipose tissue hormones were measured in all patients at baseline. Of 40 patients with moderate or severe OSAHS, 23 patients who underwent nasal continuous positive airway pressure (nCPAP) therapy were set as"nCPAP group", 14 patients who did not undergo nCPAP therapy were set as"control group", 3 patients undergoing diabetic or hypertensive treatments were excluded from further follow-up. HOMA-IR and serum levels of white adipose tissue hormones were measured in these 37 patients 1 month after nCPAP therapy. All data were recorded by computer and SPSS 11.5 for windows software was used for statistic analysis including one-way ANOVA, analysis of covariance, Chi-square test, Kruskal-Willis H test, Pearson's correlation, linear regression, and multiple regression. p < 0.05 was considered statistically significant.ResultsHOMA-IR, serum TNF-αlevels, and serum IL-6 levels were all higher in OSAHS patients at baseline. Such an increase was most significant in patients with moderate and severe OSAHS. Serum adiponectin levels were significantly lower in OSAHS patients at baseline. Such a decrease in adiponectin levels was most significant in patients with moderate and severe OSAHS. The differences of HOMA-IR and serum adiponectin levels did not change after covariate analysis (taking into account age and BMI). Insulin resistance (HOMA-IR) levels were higher in patients with target organ damage. Liner regression analysis showed insulin resistance (HOMA-IR) levels were positively correlated with AHI. Stepwise multiple regression analysis revealed that BMI and AHI were independently associated with serum adiponectin levels. After one month's follow-up, there was a significant decrease in insulin resistance (HOMA-IR) levels and serum levels of TNF-αand IL-6, and a significant increase in serum adiponectin levels in nCPAP group, while there were no similar changes in control group.ConclusionsSerum levels of adiponectin, TNF-α, and IL-6 were corrected with insulin resistance levels in patients with OSAHS. Effective nCPAP therapy might help ameliorate insulin resistance and reverse the associated target organ damage at least through decreased serum TNF-αand IL-6 levels and increased plasma adiponectin levels in OSAHS patients.