Subcutaneous Fat Tissue Thickness of the Anterior Neck and Umbilicus in Patients with Obstructive Sleep Apnea

Objective. To investigate the differences in thickness of sub- cutaneous fat tissue of the anterior neck and umbilicus of patients with and without obstructive sleep apnea (OSA), the relationship between thickness of subcutaneous fat tissue of the anterior neck and umbilicus and polysomnographic find- ings, and the influence of body mass index (BMI), anthropo- metric findings, and gender. Study Design. Cross-sectional study. Setting. Tertiary care university hospital. Subject and Methods. Seventy-three patients with OSA and 24 non-OSA patients were evaluated with polysomnography for 1 night. Anthropometric parameters and BMI were also investigat- ed. Subcutaneous fat tissue thickness of anterior neck and umbi- licus was assessed using ultrasound. The thickness of subcutane- ous fat tissue adjacent to the submandibular gland, isthmus, hyoid, suprasternal notch, and umbilicus was measured with ultrasound. Data analysis was performed using SPSS. Results. Apnea-hypopnea index (AHI) was significantly and positively correlated with age (P = .016, r 2 = 0.244), BMI (P < .001, r 2 = 0.416), and anthropometric findings (waist circum- ference P < .001, r 2 = 0.337; hip circumference P = .008, r 2 = 0.269; neck circumference P = .002, r 2 = 0.309). Minimum oxy- gen saturation was significantly, negatively correlated with age (P = .002, r 2 = −0.310), BMI (P < .001, r 2 = −0.404), and anthro- pometric findings (waist circumference P = .005, r 2 = −0.281, hip circumference P < .001, r 2 = −0.353, neck circumference P = .010, r 2 = −0.261). There were no significant differences between the OSA and non-OSA groups with respect to age (P = .178), gender (P = .189), or ultrasonographic findings for subcutaneous fat tissue thickness adjacent to the submandib- ular gland (P = .480), thyroid isthmus (P = .311), suprasternal notch (P = .950), umbilicus (P = .691), or hyoid (P = .159). Neck circumference (P = .039) and BMI (P = .014) were sig- nificantly higher in the OSA group. Conclusion. These indicate that anterior neck and umbilical subcutaneous fat tissue thickness may not contribute to the severity of OSA.