The impact of neck circumference on hypoglossal nerve stimulator therapy outcomes.

Study objectives: Hypoglossal nerve stimulation (HGNS) therapy has historically had strict eligibility requirements including a body mass index (BMI) < 32 kg/m². However, recent Food and Drug Administration approval expanded indications to a BMI < 40 kg/m². There is a wide variability in body fat distribution. This study sought to determine whether neck circumference (NC) is a better surrogate predictive variable for HGNS outcomes than BMI.

Methods: A retrospective chart review was conducted at a tertiary care center on adults who underwent HGNS implantation by a single surgeon from March 2017 to October 2021. Baseline demographic data including NC, diagnostic sleep studies, and postimplantation HGNS titration studies were collected. Linear regression and Spearman's correlation coefficient analysis were used to compare NC, percentage of predicted NC, and BMI with the apnea-hypopnea index at effective voltage.

Results: This study included 43 patients who were middle-aged (61.1 years), predominantly male (76.7%), with severe obstructive sleep apnea (median apnea-hypopnea index, 35 events/h) and mean NC of 15.3 inches. Using the NC and percentage of predicted NC, positive correlations with apnea-hypopnea index at effective voltage were observed (P = .0033, Spearman's correlation coefficient = .438 and P = .0029, Spearman's correlation coefficient = .444). While controlling for BMI, a 1-inch increase in NC was associated with a 35% increase in apnea-hypopnea index at effective voltage (P = .0411).

Conclusions: A larger NC was independently associated with worse HGNS outcomes. Further research is needed to support and confirm these findings, particularly across sexes.

Citation: Hutz MJ, Plata DM, LoSavio P, Herdegen J, Zhang Y, Mokhlesi B. The impact of neck circumference on hypoglossal nerve stimulator therapy outcomes. J Clin Sleep Med. 2024;20(11):1755-1761.