Predictors of weight loss in obese patients with obstructive sleep apnea.

PURPOSE: Consistent predictors of weight loss outcomes with very low-energy diets (VLEDs) in obstructive sleep apnea (OSA) have not been identified. This study aimed to identify variables predictive of weight loss success in obese patients with OSA undertaking an intensive weight loss programme. METHODS: We analysed biological, psychological, and behavioural variables as potential predictors of weight loss in obese patients with OSA after a 2-month VLED followed by one of two 10-month weight loss maintenance diets. Actigraphy, in-lab polysomnography, urinary catecholamines, and various psychological and behavioural variables were measured at baseline, 2, and 12 months. Spearman's correlations analysed baseline variables with 2-month weight loss, and 2-month variables with 2-12 month-weight change. RESULTS: Forty-two patients completed the VLED and thirty-eight completed the maintenance diets. Actigraphy data revealed that late bedtime (rs = - 0.45, p = < 0.01) was correlated with 2-month weight loss. The change in the time that participants got out of bed (rise-time) from baseline to two months was also correlated with 2-month weight loss (rs = 0.36, p = 0.03). The Impact of Weight on Quality of Life-Lite questionnaire (IWQOL) Public Distress domain (rs = - 0.54, p = < 0.01) and total (rs = - 0.38, p = 0.02) scores were correlated with weight loss maintenance from 2 to 12 months. CONCLUSIONS: Results from this small patient sample reveal correlations between actigraphy characteristics and weight loss in obese patients with OSA. We suggest the IWQOL may also be a useful clinical tool to identify OSA patients at risk of weight regain after initial weight loss. CLINICAL TRIAL REGISTRATION: This clinical trial was prospectively registered on 18/02/2013 with the Australia and New Zealand Clinical Trials Registry (ACTRN12613000191796). PUBLIC REGISTRY TITLE: Sleep, Lifestyle, Energy, Eating, Exercise Program for the management of sleep apnea patients indicated for weight loss treatment: A randomised, controlled pilot study. URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363680.

Magnesium supplementation for the treatment of restless legs syndrome and periodic limb movement disorder: A systematic review.

Magnesium supplementation is often suggested for restless legs syndrome (RLS) or period limb movement disorder (PLMD) based on anecdotal evidence that it relieves symptoms and because it is also commonly recommended for leg cramps. We aimed to review all articles reporting the effects of magnesium supplementation on changes in RLS and/or PLMD. We conducted a systematic search looking for all relevant articles and then two reviewers read all article titles and abstracts to identify relevant studies. Eligible studies were scored for their quality as interventional trials. We found 855 abstracts and 16 of these could not be definitively excluded for not addressing all aspects of our research question. Seven full-text articles were unlocatable and one was ineligible which left eight studies with relevant data. One was a randomised placebo-controlled trial, three were case series and four were case studies. The RCT did not find a significant treatment effect of magnesium but may have been underpowered. After quality appraisal and synthesis of the evidence we were unable to make a conclusion as to the effectiveness of magnesium for RLS/PLMD. It is not clear whether magnesium helps relieve RLS or PLMD or in which patient groups any benefit might be seen.

Diurnal changes in central blood pressure and pulse pressure amplification in patients with obstructive sleep apnoea.

STUDY OBJECTIVES: Recent evidence suggests that compared to peripheral blood pressure (BP), central BP may be more strongly associated with target organ damage and cardiovascular morbidity and mortality. Technological advances now allow the ambulatory measurement of peripheral and central BP over 24 â€‹h. For the first time, we set out to characterise the diurnal profile of central BP and pulse pressure amplification (PPA) in patients with obstructive sleep apnoea (OSA). METHODS: In this observational study, patients with moderate to severe OSA underwent 24 â€‹h central and peripheral BP testing before and after at least 4 weeks of CPAP therapy. Concurrent actigraphy was performed to confirm sleep and wake times. RESULTS: 36 patients were screened, 31 had successful testing (mean (SD) age 45 â€‹± â€‹10 years, AHI 58 â€‹± â€‹27 events/hr, Office BP 136/89 â€‹± â€‹10.7/9.5 â€‹mmHg, 32% on anti-hypertensives, 77% dippers), 21 completed testing post CPAP. Central systolic and diastolic BP followed the same nocturnal dipping profile as peripheral BP, however the peripheral pulse pressure (PP) narrowed in sleep (-3.2 â€‹mmHg, p â€‹< â€‹0.001), whereas the central PP remained unchanged (0.124 â€‹mmHg, NS), causing a significant reduction in PPA overnight (-10.7%, p â€‹< â€‹0.001). The magnitude of dip in central systolic pressure was less than peripheral systolic pressure (by 2.3 â€‹mmHg, p â€‹< â€‹0.001). After treatment with CPAP, the PPA reduction overnight was attenuated (by -3.3%, p â€‹= â€‹0.004). CONCLUSIONS: In moderate to severe OSA, central BP and PPA reduce overnight during sleep. Further randomised controlled studies are needed to quantify the differential effects of CPAP and anti-hypertensives on central versus peripheral BP.

Does Armodafinil Improve Driving Task Performance and Weight Loss in Sleep Apnea? A Randomized Trial.

RATIONALE: Patients with obstructive sleep apnea (OSA) unable to tolerate standard treatments have few alternatives. They may benefit from weight loss, but the major symptom of daytime performance impairment may remain during weight loss programs. OBJECTIVES: We hypothesized that wakefulness-promoter armodafinil would improve driving task performance over placebo in patients undergoing weight loss. METHODS: This was a placebo-controlled, double-blind, randomized trial of armodafinil versus placebo daily for 6 months in patients who were also randomized to one of two diets for 6 months with follow-up at 1 year in overweight, adult, patients with OSA who had rejected standard treatment and suffered daytime sleepiness. MEASUREMENTS AND MAIN RESULTS: Primary outcome was change in steering deviation in the final 30 minutes of a 90-minute afternoon driving task (AusED) at 6 months. Secondary outcomes were Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, and fat mass measured by dual-emission X-ray absorptiometry. Armodafinil improved driving task performance over placebo at 3 months (12.9 cm; 95% confidence interval, 4.1-21.7; P = 0.004), but not the primary time point of 6 months (5.5 cm; 95% confidence interval, -3.3 to 14.3; P = 0.223). Patients on armodafinil lost 2.4 kg more fat than those on placebo at 6 months (95% confidence interval, 0.9-4.0; P = 0.002). Other secondary outcomes were not significantly improved. CONCLUSIONS: Armodafinil did not improve driving task performance at the primary endpoint of 6 months. Armodafinil might be a useful adjunctive to weight loss in patients with OSA rejecting conventional treatments but this needs to be directly tested in a specifically designed, properly powered clinical trial. Clinical trial registered with Australian and New Zealand Clinical Trials Registry (ACTRN 12611000847910).

Maintenance diets following rapid weight loss in obstructive sleep apnea: a pilot 1-year clinical trial.

Very low energy diets (VLED) appear to be the most efficacious dietary-based obesity reduction treatments in obstructive sleep apnea (OSA); however, effective weight loss maintenance strategies remain untested in this condition. Our study aimed to assess the feasibility, tolerability and efficacy of two common maintenance diets during a 10-month follow-up period after rapid weight loss using a 2-month VLED. In this two-arm, single-centre, open-label pilot trial, obese adult OSA patients received a 2-month VLED before being allocated to either the Australian Guide to Healthy Eating diet (AGHE) or a low glycaemic index high-protein diet (LGHP). Outcomes were measured at 0, 2 and 12 months. We recruited 44 patients [113.1 ± 19.5 kg, body mass index (BMI): 37.2 ± 5.6 kg m-2 , 49.3 ± 9.2 years, 12 females]. Twenty-four patients were on continuous positive airway pressure (CPAP) or mandibular advancement splint (MAS) therapy for OSA. Forty-two patients completed the VLED. The primary outcome of waist circumference was reduced by 10.6 cm at 2 months [95% confidence interval (CI): 9.2-12.1], and patients lost 12.9 kg in total weight (95% CI: 11.2-14.6). There were small but statistically significant regains in waist circumference between 2 and 12 months [AGHE = 3.5 cm (1.3-5.6) and LGHP = 2.8 cm (0.6-5.0]. Other outcomes followed a similar pattern of change. After weight loss with a 2-month VLED in obese patients with OSA, a structured weight loss maintenance programme incorporating commonly used diets was feasible, tolerable and efficacious for 10 months. This programme may be deployed easily within sleep clinics; however, future research should first test its translation within general clinical practice.

Chronotherapy for hypertension in obstructive sleep apnoea (CHOSA): a randomised, double-blind, placebo-controlled crossover trial.

BACKGROUND: Obstructive sleep apnoea (OSA) is an important cause of secondary hypertension. Nocturnal hypertension is particularly prevalent in OSA and is a strong predictor of cardiovascular mortality. Studies in patients with essential hypertension have suggested that nocturnal administration of antihypertensives improves nocturnal blood pressure (BP) without elevating daytime BP. We evaluated the efficacy of this technique in patients with OSA with stage I/II hypertension, both before and after the addition of CPAP. METHODS: In this double-blind randomised placebo-controlled crossover trial, patients with moderate-to-severe OSA and hypertension received 6 weeks each of evening or morning perindopril with opposing time-matched placebo. CPAP therapy was subsequently added for 8 weeks in addition to either morning or evening perindopril. The primary outcome was sleep systolic BP (SBP) using 24-hour BP monitoring, analysed using linear mixed models. RESULTS: Between March 2011 and January 2015, 85 patients were randomised, 79 completed both dosing times, 78 completed the CPAP phase. Sleep SBP reduced significantly from baseline with both evening (-6.9 mm Hg) and morning (-8.0 mm Hg) dosing, but there was no difference between dosing times (difference: 1.1 mm Hg, 95% CI -0.3 to 2.5). However, wake SBP reduced more with morning (-9.8 mm Hg) than evening (-8.0 mm Hg) dosing (difference: 1.8 mm Hg, 95% CI 1.1 to 2.5). Addition of CPAP to either evening or morning dosing further reduced sleep SBP, but by a similar amount (evening: -3.2 mm Hg, 95% CI -5.1 to -1.3; morning: -3.3 mm Hg, 95% CI -5.2 to 1.5). CONCLUSIONS: Our findings support combining OSA treatment with morning administration of antihypertensives. Unlike in essential hypertension, our results do not support evening administration of antihypertensives, at least with perindopril. Further research is required before this strategy can be widely adopted into hypertension guidelines and clinical practice. TRIAL REGISTRATION NUMBER: ACTRN12611000216910, Results.

Residual Daytime Sleepiness in Obstructive Sleep Apnea After Continuous Positive Airway Pressure Optimization: Causes and Management.

Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA), but it is also common in the general population. When sleepiness remains after continuous positive airway pressure (CPAP) treatment of OSA, comorbid conditions or permanent brain injury before CPAP therapy may be the cause of the residual sleepiness. There is currently no broad approach to treating residual EDS in patients with OSA. Individual assessment must be made of comorbid conditions and medications, and of lifestyle factors that may be contributing to the sleepiness. Modafinil and armodafinil are the only pharmacologic agents indicated for residual sleepiness in these patients.