Increased systemic inflammation overnight correlates with insulin resistance among children evaluated for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) in children is associated with obesity, insulin resistance, and elevated baseline inflammation as measured by high-sensitivity C-reactive protein (hsCRP). Our goal was to evaluate whether inflammation increases overnight among children suspected of having OSA and to determine whether worsened inflammation is associated with the degree of OSA severity, obesity, and/or insulin resistance. METHODS: Twenty-three children with clinical suspicion of OSA underwent a sleep study. Levels of hsCRP were tested the evening before and morning after the sleep study. Fasting insulin and glucose levels were measured from which the homeostasis model of insulin resistance (HOMA-IR) was calculated. Linear correlations were performed to evaluate relationships between hsCRP levels at baseline and change overnight (ΔhsCRP) vs. HOMA-IR, body mass index (BMI) z-score, and sleep study parameters related to O(2) saturation and the apnea-hypopnea index (AHI). RESULTS: Among children with OSA and the entire cohort, hsCRP values were correlated with HOMA-IR and BMI z-scores. HOMA-IR but not BMI z-score correlated with ΔhsCRP overnight in the entire cohort. Sleep study parameters, including AHI mean O(2) saturation overnight, REM O(2) nadir, and non-REM O(2) nadir were not correlated with hsCRP or ΔhsCRP overnight. CONCLUSION: Among children being evaluated for OSA, degree of insulin resistance may be an important determinant of increased systemic inflammation overnight. Sleep study markers did not correlate with ΔhsCRP, leaving uncertain the role of OSA in increasing inflammation overnight. Further studies are needed to explore these associations and their potential mechanisms.

Cardiovascular effects of polymethylmethacrylate use in percutaneous vertebroplasty.

BACKGROUND AND PURPOSE: Previous investigators have described an association between polymethylmethacrylate (PMMA) use in hip arthroplasty and cardiovascular derangement. Our purpose was to evaluate the effects of PMMA injection on patient vital signs during percutaneous vertebroplasty. METHODS: We retrospectively reviewed patient charts at our institution to gather blood pressure, heart rate, and arterial oxygen saturation data for the following time points: before, during, 5 minutes after, and 10 minutes after PMMA injection during percutaneous vertebroplasty. These data were obtained for 142 injections (78 patients), and preinjection vital signs were compared with vital signs during and after PMMA injection. Multivariable regression modeling was used to ascertain the effects of cardiopulmonary comorbidities on vital signs. RESULTS: Mean arterial blood pressure and heart rate during, 5 minutes after, and 10 minutes after PMMA injection were not significantly different from their respective preprocedure values (P =.19-.92). Values for oxygen saturation during PMMA injection and 5 minutes thereafter were not significantly different from preprocedure values (P =.80 and.89, respectively). Oxygen saturation was significantly lower at 10 minutes after injection than before injection (P =.007), although the mean difference was negligible (0.6%). CONCLUSION: We find no generalized association between PMMA injection during percutaneous vertebroplasty and systemic cardiovascular derangement.