Nattapong Jaimchariyatam

Clinical and polysomnographic data of positional sleep apnea and its predictors

IntroductionIn Asian population, facial structure may contribute to the primary pathophysiology of obstructive sleep apnea (OSA). We hypothesized that sleep position may have more effect on OSA in Asians compared to the Western population. If this hypothesis is accurate, positional therapy will have a major impact on treatment of OSA among Asians.Patients/methodsWe reviewed 263 polysomnographic studies from our laboratory from January 1, 2010 to June 30, 2010. Criteria for positional and non-positional OSA were (1) supine respiratory disturbance index (RDI)/non-supine RDI ≥2 and total RDI ≥5 and (2) supine RDI/non-supine RDI <2 and total RDI ≥5, respectively. We aimed to determine the difference in baseline characteristics, polysomnographic findings, and predictors for positional OSA.ResultsWe found 144 patients diagnosed with OSA (RDI ≥5), and 96 patients met the criteria for positional OSA (67%), in which in almost half of these patients (47%), RDI was normalized (RDI < 5) in non-supine position. Snoring frequency were significantly lower among positional OSA and OSA was less severe indicated by lower RDI and arousal index, higher mean and nadir oxygen saturation, and higher %NREM3. We also found that low snoring frequency (less than 20% of total sleep time) was a significant predictor for positional OSA (odd ratio of 3.27; p = 0.011), contrarily to low mean oxygen saturation (<95%) which was found to be a negative predictor (odd ratio of 0.31; p = 0.009). Among OSA patients, low RDI (<15) was a significant predictor for normalization of RDI in non-supine position (odd ratio of 8.77; p = < 0.001), contrarily to low mean oxygen saturation (<95%) which was also found to be a negative predictor (odd ratio of 0.13; p = 0.001).ConclusionPositional OSA is very prevalent and noted in almost 70% of our patients. Low snoring frequency was noted to be a positive predictor for positional OSA, contrarily to low mean oxygen saturation which was found to be a negative predictor. These findings are encouraging that positional therapy can be very beneficial as the treatment modality for OSA among Asians.

Polysomnographic determinants of nocturnal hypercapnia in patients with sleep apnea.

STUDY OBJECTIVES Identify polysomnographic and demographic factors associated with elevation of nocturnal end-tidal CO2 in patients with obstructive sleep apnea. METHODS Forty-four adult patients with obstructive sleep apnea were selected such that the maximal nocturnal end-tidal CO2 was below 45 mm Hg in 15 studies, between 45 and 50 mm Hg in 14, and above 50 mm Hg in 15. Measurements included mean event (i.e., apneas or hypopneas) and mean inter-event duration, ratio of mean post- to mean pre-event amplitude, and percentage of total sleep time spent at an end-tidal CO2 < 45, 45-50, and > 50 mm Hg. An integrated nocturnal CO2 was calculated as the sum of the products of average end-tidal CO2 at each time interval by percent of total sleep time spent at the corresponding time interval. RESULTS The integrated nocturnal CO2 was inversely correlated with mean post-apnea duration, with lesser contributions from mean apnea duration and age (R (2) = 0.56), but did not correlate with the apnea-hypopnea index, or the body mass index. Mean post-event to mean pre-event amplitude correlated with mean post-apnea duration (r = 0.88, p < 0.001). Mean apnea duration did not correlate with mean post-apnea duration. CONCLUSIONS Nocturnal capnometry reflects pathophysiologic features of sleep apnea, such as the balance of apnea and post-apnea duration, which are not captured by the apnea-hypopnea index. This study expands the indications of capnometry beyond apnea detection and quantification of hypoventilation syndromes.

Comparison of Polysomnographic and Clinical Presentations and Predictors for Cardiovascular-Related Diseases between Non-Obese and Obese Obstructive Sleep Apnea among Asians

INTRODUCTION Unlike Caucasians, many Asians with obstructive sleep apnea (OSA) are non-obese but are affected by the disease due to predisposing craniofacial structure. Therefore, non-obese and obese OSA may represent different disease entities. The associated risk factors for developing cardiovascular-related diseases, consequently, may be considered separately for the two types of OSA. METHOD We reviewed polysomnographic studies performed in adults (aged ≥ 18 years) diagnosed with OSA (respiratory disturbance index [RDI] ≥ 5). We divided the patients into obese (body mass index [BMI] ≥ 25) and non-obese (BMI < 25) groups. We aimed to determine the differences between these two groups in terms of clinical presentations, polysomno-graphic findings, and association with cardiovascular-related diseases including hypertension, diabetes mellitus, coronary artery disease, and/or cerebrovascular disease. RESULTS Among 194 patients with OSA (RDI ≥ 5), 63.4% were non-obese and 36.6% were obese. Compared with obese OSA patients, non-obese OSA patients were noted to have smaller neck size, less prevalence of hypertension, and less history of frequent nocturia (> 3-4/week), with equal prevalence of excessive daytime sleepiness. Overall, non-obese OSA patients were noted to have milder disease indicated by lower total, supine, and non-supine, NREM RDI and higher mean and nadir oxygen saturations. In the non-obese group, only total obstructive apnea index (OAI) was noted to be a predictor for developing any of the cardiovascular-related diseases after controlling for age, sex, and RDI (odds ratio = 9.7). However, in the obese OSA group, frequent snoring (> 50% of total sleep time), low sleep efficiency (≤ 90%), and low mean oxygen saturation (< 95%) were noted to be significant predictors of cardiovascular-related diseases (odds ratios = 12.3, 4.2, and 5.2, respectively). CONCLUSION Among Asians, most OSA patients were not obese. Compared to obese OSA patients, non-obese OSA patients were noted to have less prevalence of hypertension and less history of nocturia. They were also noted to have overall milder OSA. Only OAI was noted to be a significant predictor for cardiovascular-related disease in the non-obese OSA group.

Association between respiratory events and nocturnal gastroesophageal reflux events in patients with coexisting obstructive sleep apnea and gastroesophageal reflux disease

BACKGROUND Literature has addressed the increased prevalence of gastroesophageal reflux disease (GERD) in obstructive sleep apnea (OSA). Significant improvement of GERD has been found after OSA treatment. However, precise mechanisms underlying this correlation remain unclear. We examined the association between nocturnal gastroesophageal reflux (GER) and sleep events in patients with coexisting OSA and GERD. METHODS A case-crossover study among 12 patients with coexisting moderate-severe OSA and GERD was conducted. Participants underwent simultaneous polysomnography and esophageal impedance and pH monitoring. GER subtypes (ie, acid reflux, non-acid reflux) were defined as outcomes. Respective control time points were selected in all eligible control periods. Each sleep event was assessed individually. Estimated odds ratios (ORs) and 95% confidence intervals (CIs) were analyzed. A p-value of < 0.05 was considered significant. RESULTS Patients were determined as moderate to severe OSA (respiratory disturbance index of 42.66 [±22.09]). There were a total of 50 GER episodes, 22 acid reflux and 28 non-acid reflux. Arousals and awakenings were significantly associated with subsequent GER events. The OR for GER following an arousal was 2.31 (95% CI 1.39-3.68; p < 0.001) and following an awakening was 3.71 (95% CI 1.81-7.63; p < 0.001). GER events were significantly less likely to occur after other respiratory events (OR 0.38 [95% CI 0.18-0.82]; p = 0.01). No sleep events followed GER events (p > 0.05). CONCLUSIONS Both awakening and arousal appear to precipitate any subtype of GER events in patients with coexisting GERD and moderate to severe OSA. However, GER events were significantly less likely to occur after other respiratory events and did not appear to cause sleep-related events.

Severity of Obstructive Sleep Apnea in Patients With and Without Cardiovascular-Related Diseases

BACKGROUND: Previous studies have often investigated the association of obstructive sleep apnea (OSA) with cardiovascular morbidity and mortality, but the possibility of reverse causation has not been clearly defined. OBJECTIVE: To examine if the presence of any of the cardiovascular-related diseases, including hypertension, diabetes mellitus, coronary artery disease, and/or cerebrovascular disease, correlates with more severe OSA. METHODS: This was a retrospective study where all patients age ≥ 18 years referred to our sleep laboratory for suspected OSA were included. The data from the full-night baseline and split-night polysomnographic reports were reviewed. Data were then evaluated by logistic regression analysis to compare between 2 groups, the severity of OSA (respiratory disturbance index [RDI] < 15 vs RDI ≥ 15, and RDI < 5 vs RDI ≥ 5), other polysomnographic variables and daytime sleepiness score (Epworth Sleepiness Scale [ESS] score < 10 and ≥ 10). RESULTS: 190 patients were analyzed. The patients with any of the cardiovascular-related diseases were noted to have more severe sleep apnea (RDI ≥ 15), with an adjusted odds ratio of 3.24. Sleep efficiency ≥ 90% and mean oxygen saturation ≥ 95% were observed less commonly in the patients with any of the cardiovascular-related diseases (adjusted odds ratios of 0.45 and 0.36, respectively). There was no statistically significant difference in ESS score. CONCLUSIONS: Patients with any of the cardiovascular-related diseases are at a higher risk of having moderate to severe OSA without significant increase in daytime sleepiness. Therefore, we suggest that patients with any of the cardiovascular-related diseases should be screened for OSA, even if they are asymptomatic.

Increased Sleep Disturbances in Thai Children With Attention-Deficit Hyperactivity Disorder Compared With Typically Developing Children

This study compares sleep disturbances in Thai children aged 5–12 years with attention-deficit hyperactivity disorder (ADHD) and typically developing children using the Children’s Sleep Habits Questionnaire (CSHQ)–Thai version. Fifty-five children with ADHD and 110 typically developing children were enrolled. Their parents completed the CSHQ, the ADHD rating scales, and the Strengths and Difficulties Questionnaire (SDQ). Children with ADHD had significantly higher scores in all subscales of the CSHQ compared to controls. Among children with ADHD, children with higher SDQ scores (> 15) appeared to have more sleep disturbances than those with relatively lower SDQ scores. Moreover, fewer sleep-related behavioral problems were observed in the medication treated group, which is particularly new to the field and for some perhaps not unexpected clinically.

Observational study of omeprazole for gastroesophageal reflux on pulmonary function in adult asthmatics

Abstract Background Asthma is a chronic inflammatory disease of airways. Gastroesophageal reflux disease (GERD) is known to be associated with worsening asthma. We hypothesized that treatment of GERD in asthmatics will improve asthma control and quality of life. We reviewed our experience of treatment of GERD in asthmatics in Thailand. Objectives To study the effects of omeprazole for treatment of GERD in patients with poorly controlled asthma on pulmonary function tests and asthma control test (ACT) scores. Methods This study was conducted at King Chulalongkorn Memorial Hospital between August 2009 and December 2010. Patients with partly controlled and uncontrolled asthma who were found to have GERD by 24 hour esophageal pH monitoring were administered omeprazole 40 mg per day for 8 weeks. Pulmonary function tests and ACT scores before and after treatment were compared at 4-weeks and 8-weeks follow up. Results Twenty four patients were included in this study. None of them had asthmatic attacks during the study. After 4 and 8 weeks of omeprazole treatment, the mean FEV1 (2.20 ± 0.64 L, 2.36 ± 0.58 L, respectively) and the mean ACT score (20.82 ± 3.30, 23.00 ± 1.69, respectively) were significantly higher than the pretreatment values (mean FEV1 1.99 ± 0.56 L and ACT score 16.36 ± 3.97) (P < 0.05). Conclusion High-dose omeprazole may improve pulmonary function and the level of asthma control in Thai patients with partly controlled or uncontrolled asthma and coexisting GERD.