Obesity does not modify the effect of continuous positive airway pressure on insulin resistance in adults with obstructive sleep apnoea.

This study found no evidence that obesity significantly modifies the effect of 4 months of CPAP treatment on HOMA-IR. Longer duration of CPAP treatment may be needed in order to reduce insulin resistance and determine whether obesity modifies the effect. https://bit.ly/3CtX7jZ.

Effect of Obstructive Sleep Apnea and Positive Airway Pressure Therapy on Cardiac Remodeling as Assessed by Cardiac Biomarker and Magnetic Resonance Imaging in Nonobese and Obese Adults.

It is unknown whether obesity modifies the effect of obstructive sleep apnea (OSA) and positive airway pressure (PAP) therapy on cardiac remodeling and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels. We compared NT-proBNP and cardiac magnetic resonance imaging in adults without OSA (n=56) and nonobese (n=73; body mass index <30 kg/m2) and obese (n=136; body mass index ≥30 kg/m2) adults with OSA. We also investigated these traits in nonobese (n=45) and obese (n=78) participants with OSA adherent to 4 months of PAP treatment. At baseline, left ventricular mass to end-diastolic volume ratio, a measure of left ventricular concentricity, was greater in both nonobese and obese participants with OSA compared with those without OSA. Participants with OSA and obesity exhibited reduced phasic right atrial function. No significant differences in baseline NT-proBNP were observed across groups. The effect of PAP treatment on NT-proBNP and left atrial volume index was significantly modified by obesity. In nonobese participants, PAP therapy was associated with a decrease in NT-proBNP (P<0.0001) without a change in left atrial volume index, whereas in obese participants, PAP was associated with an increase in left atrial volume index (P=0.006) without a change in NT-proBNP. OSA was associated with left ventricular concentric remodeling independent of obesity and right atrial dysfunction in participants who were obese. PAP treatment was associated with reduced NT-proBNP in nonobese participants with OSA, but left atrial enlargement in obese participants with OSA, suggesting that PAP-induced reduction in BNP release (which is known to occur during obstructive apnea episodes) may lead to volume retention in obese participants with OSA. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01578031.

Changes in sleepiness and 24-h blood pressure following 4 months of CPAP treatment are not mediated by ICAM-1.

OBJECTIVE: Continuous positive airway pressure (CPAP) therapy reduces circulating intercellular adhesion molecule 1 (ICAM-1) in adults with obstructive sleep apnea (OSA). ICAM-1 levels may affect the daytime sleepiness and elevated blood pressure associated with OSA. We evaluated the association of changes from baseline in ICAM-1 with changes of objective and subjective measures of sleepiness, as well as 24-h ambulatory blood pressure monitoring (ABPM) measures, following 4 months of CPAP treatment. METHODS: The study sample included adults with newly diagnosed OSA. Plasma ICAM-1, 24-h ABPM, Epworth Sleepiness Scale (ESS), and psychomotor vigilance task (PVT) were obtained at baseline and following adequate CPAP treatment. The associations between changes in natural log ICAM-1 and changes in the number of lapses on PVT, ESS score, and 24-h mean arterial blood pressure (MAP) were assessed using multivariate regression models, controlling for a priori baseline covariates of age, sex, BMI, race, site, smoking status, physical activity, anti-hypertensive medications, AHI, and daily hours of CPAP use. RESULTS: Among 140 adults (83% men), mean (± SD) body mass index (BMI) was 31.5 ± 4.2 kg/m2, and apnea-hyopnea index (AHI) was 36.8 ± 15.3 events/h. Sleepiness measures, although not ICAM-1 or ABPM measures, improved significantly following CPAP treatment. We observed no statistically significant associations between the change in ICAM-1 and changes in sleepiness, MAP, or other ABPM measures. CONCLUSION: Changes in ICAM-1 levels were not related to changes in sleepiness or ABPM following CPAP treatment of adults with OSA. Future work should explore whether or not other biomarkers may have a role in mediating these treatment outcomes in adults with OSA.

Use of a dual-layer amniotic membrane in the treatment of diabetic foot ulcers: an observational study.

BACKGROUND: Despite advances in the treatment, fewer than half of diabetic foot ulcers (DFUs) heal in 12 weeks and 85% of non-traumatic amputations follow the development of a DFU. The search for treatment options continues. Placental-derived products have shown promise in the treatment of DFUs. This study investigates Artacent (Tides Medical, US), a unique amniotic patch containing two layers of amnion and its potential to increase growth factor delivery. METHOD: This observational analysis included patients with DFUs with documented failure to heal by >50% after the protocol-defined run-in period (either two or four weeks) of standard of care (SOC), and who had been randomised in a larger clinical trial that had been discontinued earlier for logistical reasons. Patients were randomised to either weekly or biweekly application of the dual-layer amniotic membrane (DLAM) plus SOC and were included in per-protocol effectiveness analyses. Descriptive statistics were chosen for this analysis. Primary endpoint was complete closure at 12 weeks. RESULTS: A total of 26 patients were included in the analysis. Examination of baseline patient characteristics revealed that the ulcers were larger than in most DFU clinical trials (4.65±4.89cm2). For the primary endpoint, 17/26 (65%, 95% CI: 44-83%) of the combined treatment arms achieved complete closure. The small sample size precluded a meaningful comparison of healing between weekly and biweekly DLAM applications. CONCLUSION: The observations taken from the discontinued clinical trial suggest that the DLAM promotes healing of DFUs. The healing rates are similar to those in other placental-based tissue studies. In addition, the relatively larger size of the ulcers suggests that the DLAM may be effective in ulcers that are more resistant to standard of care. In the future, a revised clinical trial with a greater sample size is planned.

Implant placement accuracy in total knee arthroplasty: validation of a CT-based measurement technique.

BACKGROUND: The primary goal of many computer-assisted surgical systems like robotics for total knee arthroplasty (TKA) is to accurately execute a preoperative plan. To assess whether the preoperative plan was executed accurately in 3D, one option is to compare the planned and postoperative implant placement using a preoperative and postoperative CT scan of the patient's limb. This comparison requires a 3D-to-3D surface registration between the preoperative and postoperative 3D bone models and between the planned and postoperative 3D implants. Hence, the present study aimed at validating this measurement technique by determining (I) the anatomical regions that result in the lowest 6-degree of freedom (DoF) errors for 3D-to-3D surface registration of bone models, (II) the 6-DoF errors for 3D-to-3D surface registration of the implant models, and (III) the 6-DoF of the complete measurement technique. METHODS: Four different regions of the femur were tested to determine which one would result in the most accurate 3D-to-3D registration of the bone models using 12 cadaveric lower limb specimens. Next, total knee arthroplasties were performed on six specimens, and the accuracy of the 3D-to-3D implant registration was evaluated against a gold standard registration performed using fiducial markers. RESULTS: The most accurate 3D-to-3D bone registration was obtained when using the largest anatomical regions available after TKA, being the full 3D femur model or the femur model without the distal femur which resulted in root mean square errors within 0.2 mm for translations and 0.2° for rotation. The accuracy of the 3D-to-3D femoral and tibial implant registration was within 0.7 mm for translations and 0.4°-0.6° for rotations, respectively. The accuracy for the overall procedure was within 0.9 mm and 0.6° for both femur and tibia when using femoral regions resulting in accurate 3D-to-3D bone registration. CONCLUSIONS: In conclusion, this measurement technique can be used in applications where measurement errors up to 0.9 mm in translations and up to 0.6° in rotations in component placement are acceptable.

Blood pressure response to treatment of obese vs non-obese adults with sleep apnea.

Many patients with obstructive sleep apnea (OSA), but not all, have a reduction in blood pressure (BP) with positive airway pressure (PAP) treatment. Our objective was to determine whether the BP response following PAP treatment is related to obesity. A total of 188 adults with OSA underwent 24-hour BP monitoring and 24-hour urinary norepinephrine collection at baseline. Obesity was assessed by waist circumference, body mass index, and abdominal visceral fat volume. Participants adherent to PAP treatment were reassessed after 4 months. Primary outcomes were 24-hour mean arterial pressure (MAP) and 24-hour urinary norepinephrine level. Obstructive sleep apnea participants had a significant reduction in 24-hour MAP following PAP treatment (-1.22 [95% CI: -2.38, -0.06] mm Hg; P = .039). No significant correlations were present with any of the 3 obesity measures for BP or urinary norepinephrine measures at baseline in all OSA participants or for changes in BP measures in participants adherent to PAP treatment. Changes in BP measures following treatment were not correlated with baseline or change in urinary norepinephrine. Similar results were obtained when BP or urinary norepinephrine measures were compared between participants dichotomized using the sex-specific median of each obesity measure. Greater reductions in urinary norepinephrine were correlated with higher waist circumference (rho = -0.21, P = .037), with a greater decrease from baseline in obese compared to non-obese participants (-6.26 [-8.82, -3.69] vs -2.14 [-4.63, 0.35] ng/mg creatinine; P = .027). The results indicate that the BP response to PAP treatment in adults with OSA is not related to obesity or urinary norepinephrine levels.

Physical Activity Following Positive Airway Pressure Treatment in Adults With and Without Obesity and With Moderate-Severe Obstructive Sleep Apnea.

STUDY OBJECTIVES: To examine the level of physical activity (PA) before and following positive airway pressure (PAP) treatment in adults who have obstructive sleep apnea (OSA) with obesity versus without obesity. METHODS: Simultaneous waist accelerometer and wrist actigraphy recordings were obtained in 129 adults with obesity and 69 adults without obesity and who had OSA prior to and following 4 months of PAP therapy and in 52 patients in a control group. Primary PA measurements were average steps per day on waist accelerometry and average counts per minute (CPM) per day on wrist actigraphy. RESULTS: At baseline, participants with obesity and OSA exhibited fewer steps per day on waist accelerometer and fewer CPM per day on wrist actigraphy compared to participants without obesity and with OSA (despite similar apnea-hypopnea index between groups). Following PAP treatment, participants with OSA had modestly increased CPM per day on wrist actigraphy (17.69 [95% confidence interval (CI), 5.67-29.71], P = .005) and increased light PA time (0.26 [95% CI, 0.07-0.44] hours, P = .008) on waist accelerometer. Participants without obesity and with OSA had greater improvements in PA measures on average compared to participants with obesity and OSA, although the differences were not statistically significant. Weight increased following PAP treatment in the participants with obesity and OSA (1.71 [95% CI, 0.41-3.02] kg, P = .010) but was unchanged in the group without obesity (0.93 [95% CI, -0.89 to 2.76] kg, P = .311). CONCLUSIONS: Compared to study participants without obesity and with OSA, participants with obesity and OSA had reduced PA at baseline. PA increased significantly in participants without obesity, with OSA, and who were adherent to PAP treatment. Results indicate that treatment of OSA is unlikely to be associated with a change in PA in adults with obesity and OSA and help explain the absence of weight loss following PAP treatment in adults with OSA. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov, title: The Effects of Treating Obese and Lean Patients With Sleep Apnea (PISA), identifier: NCT01578031, URL: https://clinicaltrials.gov/ct2/show/NCT01578031.

Carotid Artery Wall Thickness in Obese and Nonobese Adults With Obstructive Sleep Apnea Before and Following Positive Airway Pressure Treatment.

Study objectives: Debate persists as to whether obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. The purpose of this study was to compare carotid intima-media thickness (IMT), an early sign of atherosclerosis, in obese and nonobese adults with OSA before and following positive airway pressure (PAP) treatment. Methods: A total of 206 adults newly diagnosed with OSA with an apnea-hypopnea index (AHI) of 15-75 events/hour and 53 controls with AHI <10 were studied. Waist circumference was used to classify participants as obese and nonobese. Bilateral common carotid artery B-mode ultrasound was performed at baseline to assess IMT, arterial diameter, arterial-wall mass, and circumferential wall stress. Measurements were repeated in 118 participants with OSA who completed a 4-month PAP treatment and had an average daily use over that period of ≥4 hours/day. Results: No significant differences in carotid IMT, diameter, or arterial-wall mass were present at baseline between participants with OSA and controls stratified by waist circumference, after adjusting for other cardiovascular risk factors. In participants with OSA, who had adequate PAP adherence over the 4-month treatment, carotid artery diameter significantly increased (mean change [95% confidence interval] = 0.13 [0.06, 0.20] mm; p = .0004), but no significant changes in carotid IMT, arterial-wall mass, and circumferential stress were observed in obese and nonobese participants. Conclusions: Regardless of obesity status, carotid IMT is not increased in adults with moderate to severe OSA versus controls and does not change following 4 months of PAP treatment.