An Obese Female with Prader-Willi Syndrome and Daytime Sleepiness

GH was approved for Prader-Willi Syndrome (PWS) in 2000. Fatalities in individuals with PWS soon after beginning GH treatment prompted concern about GH worsening sleep apnea. We sought to determine whether GH affects sleep apnea in individuals with PWS. Twenty-five patients with PWS had overnight polysomnography (PSA) at baseline and 6 wk after starting GH. The study was conducted in a sleep lab using a standardized procedure. The patients studied had genetically confirmed PWS. PSA results were analyzed for frequency and severity of central and obstructive apnea/hypopnea events and total apnea/hypopnea index. As a group, GH improved apnea/hypopnea index by a mean of 1.2 events per hour (P = 0.02) and central events by a median of 1.7 events per hour (P < 0.001). Fourteen patients had improvement in obstructive events by a mean of 1.7 events per hour. Six patients had worsening of obstructive events on GH. Four of these patients had upper respiratory tract infections at the time of the second PSA and had tonsil/adenoid hypertrophy on otorhinolaryngological evaluation. Two patients with high serum IGF-I levels had increased obstructive events. Most of our PWS patients had improvement after short-term GH treatment, but 32% had worsening of sleep disturbance. A subset of PWS patients are at risk during this window of vulnerability shortly after initiation of GH. Because it is difficult to predict who will worsen with GH, patients with PWS should have PSA before and after starting GH and should be monitored for sleep apnea with upper respiratory tract infections. Otorhinolaryngological evaluation is warranted if sleep apnea worsens on GH. IGF-I levels should be monitored, with the goal being physiological levels.

Sleep-related breathing disorders are common in individuals with Prader-Willi syndrome (PWS). The US Food and Drug Administration approved the use of growth hormone in PWS in 2000. Many infants with PWS are being started on growth hormone therapy, but no data exist on the respiratory effects of growth hormone treatment in this age group. To perform overnight polysomnographic studies to evaluate the effects of growth hormone on sleep-related breathing in infants with PWS. Pilot study evaluating overnight polysomnography before and 6 weeks after initiation of growth hormone therapy at a dose of 1 mg/m2 per day in 20 infants from 2 to 21 months of age with genetically confirmed PWS. Polysomnography results were analyzed for frequency and severity of obstructive and central apnea and hypopnea events and the overall apnea-hypopnea index. When data were analyzed for the total group, there were no significant changes in sleep-related disorders before and after institution of growth hormone therapy. However, 12 infants had an increase in the frequency of obstructive events associated with either upper respiratory infections or a diagnosis of gastroesophageal reflux at the second sleep study (after institution of growth hormone therapy). Resolution of these conditions was associated with normalization of polysomnography results on follow-up studies. Overall, growth hormone therapy, per se, had no significant effect on sleep related-breathing disorders in infants with PWS. Infants with upper respiratory infections of gastroesophageal reflux may be at risk for developing more obstructive events after beginning growth hormone treatment. We recommend close monitoring of infants with PWS after they begin growth hormone therapy, especially when they have upper respiratory infections.

This study aimed to examine the effect of sleep state (rapid eye movement [REM] versus non-rapid eye movement [NREM]) and position (supine versus non-supine position) on obstructive respiratory events distribution in adolescent population (ages 12 to 18 y). This was a retrospective study that included 150 subjects between the ages of 12 to 18 y with an apnea-hypopnea index (AHI) > 1/h. Subjects using REM sleep-suppressant medications and subjects with history of genetic anomalies or craniofacial syndromes were excluded. The median age was 14 y with interquartile range (IQR) of 13 to 16 y, 56% of patients were males and the median body mass index (BMI) z-score was 2.35 (IQR: 1.71-2.59) with 77.3% of patients fulfilling obesity criteria. Respiratory obstructive events were more common in REM sleep. The median REM obstructive AHI (OAHI) was 8.9 events per hour (IQR: 2.74-22.8), whereas the median NREM OAHI was 3.2 events per hour (IQR: 1.44-8.29; p < 0.001). African American adolescents had more REM obstructive events with median REM OAHI of 13.2 events per hour (IQR: 4.88-30.6), which was significantly higher than median REM OAHI of 4.94 (IQR: 2.05-11.36; p = 0.004) in white adolescents. Obstructive events were more common in supine position with higher median supine OAHI of 6.55 (IQR: 4-17.73) when compared to median non-supine OAHI of 2.94 (IQR: 1-6.54; p < 0.001). This study shows that sleep related obstructive respiratory events in the adolescents (12 to 18 y of age) occur predominantly in REM sleep and in supine position.

To assess the accuracy of novel algorithms using an oximeter-based finger plethysmographic signal in combination with a nasal cannula for the detection and differentiation of central and obstructive apneas. The validity of single pulse oximetry to detect respiratory disturbance events was also studied. Patients recruited from four sleep laboratories underwent an ambulatory overnight cardiorespiratory polygraphy recording. The nasal flow and photoplethysmographic signals of the recording were analyzed by automated algorithms. The apnea hypopnea index (AHI(auto)) was calculated using both signals, and a respiratory disturbance index (RDI(auto)) was calculated from photoplethysmography alone. Apnea events were classified into obstructive and central types using the oximeter derived pulse wave signal and compared with manual scoring. Sixty-six subjects (42 males, age 54 ± 14 yrs, body mass index 28.5 ± 5.9 kg/m(2)) were included in the analysis. AHI(manual) (19.4 ± 18.5 events/h) correlated highly significantly with AHI(auto) (19.9 ± 16.5 events/h) and RDI(auto) (20.4 ± 17.2 events/h); the correlation coefficients were r = 0.94 and 0.95, respectively (p < 0.001) with a mean difference of -0.5 ± 6.6 and -1.0 ± 6.1 events/h. The automatic analysis of AHI(auto) and RDI(auto) detected sleep apnea (cutoff AHI(manual) ≥ 15 events/h) with a sensitivity/specificity of 0.90/0.97 and 0.86/0.94, respectively. The automated obstructive/central apnea indices correlated closely with manually scoring (r = 0.87 and 0.95, p < 0.001) with mean difference of -4.3 ± 7.9 and 0.3 ± 1.5 events/h, respectively. Automatic analysis based on routine pulse oximetry alone may be used to detect sleep disordered breathing with accuracy. In addition, the combination of photoplethysmographic signals with a nasal flow signal provides an accurate distinction between obstructive and central apneic events during sleep.

Dampened surge in heart rate at respiratory event termination in children with Prader-Willi syndrome.

The aim was to determine the feasibility of using an unattended 2-channel device to screen for obstructive sleep apnea in a population of high-risk patients using a targeted, case-finding strategy. The case finding was based on the presence of risk factors not symptoms in the studied population. The study took place from June 2007 to May 2008 in rural and metropolitan Queensland and New South Wales. Family doctors were asked to identify patients with any of the following: BMI > 30, type 2 diabetes, treated hypertension, ischemic heart disease. Participants applied the ApneaLink+O2 at home for a single night. The device recorded nasal flow and pulse oximetry. Data were analyzed by proprietary software, then checked and reported by either of two sleep physicians. 1,157 patients were recruited; mean age 53 ± 14.6, M/F% = 62/38, mean BMI = 31.8, obesity = 35%, diabetes = 16%, hypertension = 39%, IHD = 5%, Mean Epworth Sleepiness Scale score (ESS) = 8.3. The prevalence of unrecognized OSA was very high: 71% had an AHI > 5/h, 33% had an AHI > 15/h, and 16% had an AHI > 30/h. The ApneaLink+O2 device yielded technically adequate studies in 93% of cases. The study shows that a "real world" simple low cost case finding and management program, based on unattended home monitoring for OSA, can work well in a population with risk factors and comorbidities associated with OSA, independent of the presence of symptoms. The prevalence of unrecognized OSA was very high.

Hypocretin (Hcrt) is a neurotransmitter of the dorsal and lateral hypothalamus that regulates sleep, appetite, and energy consumption. Recent evidence indicates that it is also involved in pleasure/reward-seeking. Mutation of the Hcrt-receptor gene causes narcolepsy in canines, and Hcrt knockout mice exhibit narcolepsy-like symptoms. Human narcoleptics do not commonly have mutations in the ligand or receptor but do have degeneration of Hcrt-containing neurons, possibly through an autoimmune mechanism. When Hcrt neurons degenerate in mice, hypophagia and obesity are observed, symptoms that are also present in some human narcoleptics. This article reviews the recent literature with regard to the many functions of this single molecule. The authors suggest that eating habits and impulsivity may be topics worth exploring in the evaluation of narcoleptic patients.

Introduction Sleep-disordered breathing (SDB) is common in patients with Prader–Willi Syndrome (PWS). However, the prevalence of SDB varies widely between studies. Early identification of SDB and factors contributing to its incidence is essential, particularly when considering growth hormone (GH) therapy. Objectives The aims of the study were to describe the prevalence and phenotypes of sleep-disordered breathing (SDB) in patients with Prader–Willi syndrome (PWS) and to determine the effects of age, gender, symptoms, GH therapy and body mass index on SDB severity. Methods This study was a retrospective chart review of all patients with genetically confirmed Prader–Willi syndrome who underwent diagnostic overnight polysomnography (PSG) in the sleep laboratory at Sidra Medicine. Clinical and PSG data of enrolled patients were collected. Results We identified 20 patients (nine males, eleven females) with PWS who had overnight sleep polysomnography (PSG) at a median age (IQR) of 5.83 (2.7–12) years. The median apnea-hypopnea index (AHI) was 8.55 (IQR 5.8–16.9) events/hour. The median REM-AHI was 27.8 (IQR 15–50.6) events/hour. The median obstructive apnea-hypopnea index (OAHI) was 7.29 (IQR 1.8–13.5) events/hour. The median central apnea-hypopnea index (CAHI) was 1.77 (IQR 0.6–4.1) events/hour. Nineteen patients (95%) demonstrated SDB by polysomnography (PSG) based on AHI ≥1.5 events/hour. Nine patients (45%) were diagnosed with obstructive sleep apnea (OSA). Three patients (15%) were diagnosed with central sleep apnea (CSA). Seven patients (35%) were diagnosed with mixed sleep apnea. No correlations were observed between AHI and age, gender, BMI, symptoms, or GH therapy. However, REM-AHI was significantly correlated with BMI (P=0.031). Conclusion This study shows a high prevalence of SDB among our patients with PWS. Obstructive sleep apnea was the predominant phenotype. BMI was the only predictor for high REM-AHI. Further studies of large cohorts are warranted to define SDB in PWS and design the appropriate treatment.

Obstructive sleep disorders in Prader–Willi syndrome: The role of surgery and growth hormone

Sleep disordered breathing and growth hormone therapy in children with Prader Willi syndrome

Obesity, insulin resistance, and puberty seem to influence and been inversely associated with 25-hydroxy vitamin D (25OHD) levels. To our knowledge, a study on 25OHD in children and adolescents with Prader-Willi syndrome (PWS), a genetic form of obesity, is not yet available. To analyze the 25OHD values in pediatric PWS subjects in comparison with a control group (CNT), highlighting the possible correlations with IR, BMD, body composition, pubertal stage, and GH therapy (GHT). Auxological and laboratory parameters, HOMA-IR, Vitamin D status, and bone density and body composition by DEXA scan were analyzed in 52 PWS and 110 controls (CNT), gender-, age-, and BMI-SD matched. None of them was on calcium or vitamin D. 20 PWS were on growth hormone (GH) therapy and 32 were previously treated. Altogether, PWS had similar values of 25OHD compared to CNT.16 PWS (30.7%) and 27 CNT (24.5%) had low 25OHD levels (<20ng/ml) (p=NS). 25OHD of PWS on GHT were comparable to those previously treated. In both groups, univariate analysis showed a negative correlation between 25OHD and fat mass% (FM%). GH therapy and pubertal stage were positively correlated with bone parameters analyzed by DXA. Multivariate regression confirmed only FM% as negative predictor of 25HOD in PWS patients, as previously described. GHT does not seem to influence 25OHD in PWS. Our data showed that PWS had similar values of 25OHD compared to CNT. As already described, FM seems to be the only parameter influencing 25OHD levels. Finally, GHT does not seem to influence 25OHD metabolism in PWS.

Growth hormone (GH) therapy is now widely given to Prader-Willi syndrome (PWS) patients to encourage growth in body height and to prevent obesity. Scoliosis, one of the complications in this syndrome, is thought to be accelerated in parallel with a rapid increase in body height, especially during adolescence. To determine whether GH therapy aggravates scoliosis and to identify any factor which might predict the progression of scoliosis, we studied 35 (22 males and 13 female) PWS patients between the ages of 2-16 years on GH therapy whose scoliosis was followed with spinal X-rays every 6 months. Thirteen (37.1%) of 35 patients had scoliosis with a Cobb angle of over 10°. Scoliosis was unchanged in five patients (14.3%), became worse in six (17.1%) and improved in two (5.7%). All 22 (62.9%) of 35 patients who did not have scoliosis did not develop scoliosis with GH therapy. Since abnormal paraspinal muscle development was thought to induce scoliosis, we measured cross-sectional areas of paraspinal muscles by using one slice CT scan at the level of the umbilicus at the level of L4. Since there was a delay in the increase in total paravertebral muscle area and prolonged asymmetry in patients with progressive scoliosis, both were thought to be useful predictors of progressive scoliosis in PWS patients with GH therapy.

Background Prader-Willi syndrome (PWS) is associated with marked obesity that can lead to severe complications such as diabetes mellitus. Early adiposity rebound (AR) is associated with future obesity and an increased risk of diabetes mellitus and metabolic syndrome. Previous reports have shown that the onset of AR occurred earlier in diseases that cause obesity. However, there have been no studies focusing on the timing of AR in PWS, or on the effect of growth hormone (GH) treatment on AR. The aim of this study was to explore AR in PWS patients and to analyze the effect of GH treatment on AR. Methods This retrospective study evaluated 48 patients, with 16 of the patients found to have AR prior to GH treatment. AR was constructed for each patient using Microsoft Excel, and the exact point of the nadir of body mass index (BMI) following the initial peak was determined. We additionally analyzed the relationship between GH treatment and the timing of AR onset. Results AR onset for patients found to have AR before starting GH treatment was 16.0 (13.0-21.0) months. In contrast, AR onset for patients found to have AR after starting GH treatment was 27.5 (23.8-36.3) months. The difference between the two groups was statistically significant (p=0.0001). A positive correlation was found between the GH treatment period and AR (p=0.00013). Conclusion The median age of AR onset in PWS patients was 16.0 (13.0-21.0) months, and GH treatment might delay the early AR onset.

Patients with Prader-Willi syndrome (PWS) suffer from excessive sleepiness and sleep disordered breathing (SDB). We reviewed the polysomnograms (PSGs) and multiple sleep latency tests (MSLTs) in a cohort of PWS patients to determine the relationship of BMI(Z) scores, daytime sleepiness, growth hormone (GH) treatments, and SDB. Attended overnight PSGs were performed for PWS patients referred for concern for SDB between January 2000 and January 2005. Age at time of study, genotype, use and dose of GH, sleepiness scale, normalized body-mass index (BMI(Z)), total sleep time, latency to stage I and REM sleep, sleep stage percentages, apnea-hypopnea index (AHI), central apnea (CA) frequency, oxygen saturation nadir, maximum carbon dioxide tension, periodic limb movement index, presence of snoring, normality of EEG, and, in several patients, mean sleep latency testing were determined. All patients exhibited some form of SDB. There was a positive correlation between the BMI(Z) and AHI. The BMI(Z) was significantly different between GH-treated and -untreated groups, but there was not a significant difference between AHI, CA, oxygen nadir, or maximum carbon dioxide tension of the GH-treated and -untreated groups. There was no significant correlation between the MSLT and the sleepiness scale or AHI. There was also no significant difference between the AHIs of patients with different genetic defects. There should be a low threshold for obtaining PSG to evaluate SDB, but the type and severity of SDB were not predictable based on a sleepiness scale score, BMI(Z), or underlying genetic defect.

Introduction Prader-Willi syndrome (PWS) is the most common syndromic form of obesity, and the majority of the cases arise sporadically. Patients with PWS are at a high risk of sleep-related disorders, such as obstructive sleep apnea (OSA), central sleep apnea (CSA), and nocturnal hypoventilation. Management of untreated sleep apnea is essential before starting growth hormone (GH) therapy for the treatment of PWS. We present a patient with PWS who was noted to have complicated sleep apnea during the preemptive workup, prompting the initiation of positive airway pressure (PAP) therapy. Report of case An 11-year-old male with PWS presented to the sleep medicine clinic for screening of sleep apnea before starting GH therapy. His past sleep medicine workup included a polysomnogram (PSG) at the age of 4 years, showing an apnea-hypopnea index (AHI) of 14.1/hour. He underwent tonsillectomy and adenoidectomy (T&amp;A) after that study at the age of 4 and 7 years, and the repeat PSG showed residual OSA with AHI of 2.5/hour. The patient was not able to tolerate PAP therapy and was managed conservatively. On present evaluation, significant findings were excessive daytime sleepiness (EDS) with pediatric Epworth Sleepiness Score of 14/24, weight/age percentile of 62, and grade 2 facial malocclusion. Overnight PSG was performed, which showed an AHI of 8.0/hour (obstructive AHI 3.8/hour and central AHI of 4.2/hour, suggesting CSA), minimum oxygen saturation of 84%, average end-tidal carbon dioxide of 45.1 mm Hg, and time above 50 mm Hg of 40.2% of the total sleep time (suggesting nocturnal hypoventilation). A PAP titration study was done, which achieved adequate control with bilevel positive airway pressure (BPAP) of 12/8 cm H2O with a backup respiratory rate of 8 breaths per minute. The patient tolerated this therapy well during the titration study, and BPAP with the above settings was prescribed. Conclusion The management of sleep apnea in individuals with PWS remains challenging. Unlike in non-syndromic cases of pediatric sleep apnea, T&amp;A is not as effective in these patients, who eventually require treatment with PAP therapy. Narcolepsy and cataplexy-like phenotypes are also common in this population, which also need to be adequately screened and treated. Support (if any)