Faculty Bibliography

BACKGROUND:The impact of middle turbinate resection (MTR) on olfaction remains a point of debate in the current literature. Few studies have objectively evaluated olfactory cleft airflow following MTR; thus, the mechanism by which MTR may impact olfaction is poorly understood. It is not known whether the postsurgical changes in airway volume, flow, and resistance increase odorant transport or disrupt the patterns of normal airflow. Computational fluid dynamics can be used to study the nasal airway and predict responses to surgical intervention. OBJECTIVE:To evaluate the functional impact of MTR on nasal airflow, resistance, and olfaction. METHODS:Five maxillofacial computed tomography scans of patients without signs of significant sinusitis or nasal polyposis were used. Control models for each patient were compared to their corresponding model after virtual total MTR. For each model, nasal airway volume, nasal resistance, and air flow rate were determined. Odorant transport of 3 different odorants in the nasal cavity was simulated based on the computed steady airflow field. RESULTS:Total airflow significantly increased following bilateral MTR in all patient models ( P < .05). Consistent with our airflow results, we found a decrease in nasal resistance following MTR. MTR significantly increased area averaged flux to the olfactory cleft when compared to controls for phenylethyl alcohol (high-sorptive odorant). Results for carvone (medium sorptive) were similarly elevated. MTR impact on limonene, a low flux odorant, was equivocal. CONCLUSION/CONCLUSIONS:MTR increases nasal airflow while decreasing the nasal resistance. Overall, olfactory flux increased for high sorptive (phenylethyl alcohol) and medium sorpitve (l-carvone) odorants. However, the significant variation observed in one of our models suggests that the effects of MTR on the nasal airflow and the resultant olfaction can vary between individuals based on individual anatomic differences.

BACKGROUND:Insulin resistance increases during adolescence in those with type 1 diabetes mellitus (T1DM), complicating glycemic control and potentially increasing cardiovascular disease (CVD) risk. Metformin, typically used in type 2 diabetes mellitus (T2DM), is a possible adjunct therapy in T1DM to help improve glycemic control and insulin sensitivity. OBJECTIVE:We hypothesized that metformin would improve metabolic parameters in adolescents with T1DM. DESIGN, SETTING, AND PARTICIPANTS/METHODS:This randomized, double-blinded, placebo-controlled trial included 74 pubertal adolescents (ages: 13-20 yr) with T1DM. Participants were randomized to receive either metformin or placebo for 6 months. Glycated hemoglobin (HbA1c), insulin dose, waist circumference, body mass index (BMI), and blood pressure were measured at baseline, 3 and 6 months, with fasting lipids measured at baseline and 6 months. RESULTS:Total daily insulin dose, BMI z-score and waist circumference significantly decreased at 3 and 6 months compared to baseline within the metformin group, even among normal-weight participants. In the placebo group, total insulin dose and systolic blood pressure increased significantly at 3 months and total insulin dose increased significantly at 6 months. No significant change was observed in HbA1c at any time point between metformin and placebo groups or within either group. CONCLUSIONS:Low-dose metformin likely improves BMI as well as insulin sensitivity in T1DM adolescents, as indicated by a decrease in total daily insulin dose. The decrease in waist circumference indicates that fat distribution is also likely impacted by metformin in T1DM. Further studies with higher metformin doses and more detailed measurements are needed to confirm these results, their underlying mechanisms, and potential impact on CVD in T1DM youth.

OBJECTIVES/OBJECTIVE:Prior research has demonstrated poor correlation between the obstructive apnea-hypopnea index (AHI) on full-night polysomnogram (PSG) and quality-of-life (QOL) scores. We aim to examine the association between rapid eye movement (REM) AHI and QOL scores in children with sleep-disordered breathing (SDB). STUDY DESIGN/METHODS:Prospective trial. SETTING/METHODS:Two tertiary children's hospitals. SUBJECTS AND METHODS/METHODS:Children between 3 and 16 years of age with suspected SDB who were undergoing PSG were eligible. Children with craniofacial anomalies were excluded. Subjects' caregivers completed the Obstructive Sleep Apnea-18 (OSA-18), a validated QOL survey. Power analysis determined a group size of 34. RESULTS:One hundred twenty-seven patients were enrolled. The mean (SD) age was 6.3 (3.3) years. Most subjects (52%) were black and 26% were obese. The mean (SD) obstructive AHI of the subject population was 5.4 (11.9), while the mean (SD) REM AHI was 13.1 (23.7). The mean total OSA-18 score was 65.2, indicating a moderate impact of SDB on QOL. Neither the obstructive AHI (P = .73) nor the REM AHI (P = .49) correlated with total OSA-18 scores. However, lower nadir oxygen saturation was associated with significantly poorer QOL (P = .02). The sleep disturbance OSA-18 subset score significantly correlated with both the obstructive AHI (r (2) = 0.22; P = .01) and the REM AHI (r (2) = 0.22; P = .01); the remaining 4 subset scores did not correlate with either factor. CONCLUSION/CONCLUSIONS:Neither obstructive AHI nor REM AHI correlates with total OSA-18 QOL scores. With the exception of nadir oxygen saturation, PSG parameters do not reflect the burden of SDB on QOL in children.