Toshiaki Shiomi

Metabolic Syndrome in Japanese Patients with Obstructive Sleep Apnea Syndrome

We investigated the prevalence of metabolic syndrome in patients with obstructive sleep apnea syndrome (OSAS) referred to a tertiary university–based medical center. A cross-sectional study of patients with a definite diagnosis of OSAS was performed using new diagnostic criteria for metabolic syndrome that were designed for the Japanese population. Clinical features and comorbidities related to metabolic syndrome were compared between 819 patients with OSAS (719 men and 100 women) and 89 control subjects without OSAS. Metabolic syndrome was significantly more common in the patients with OSAS than in the controls (49.5% vs. 22.0% for men, p<0.01; 32.0% vs. 6.7% for women, p<0.01). Men with OSAS (apnea-hypopnea index [AHI;[ge;5/h) had a higher risk of metabolic syndrome compared with controls (odds ratio [OR]: 3.47; 95% confidence interval [CI]: 1.84–6.53). There was a significantly increased risk of metabolic syndrome in men with moderate OSAS (AHI: 15–29.9/h) (OR: 2.83; 95% CI: 1.42–5.66) and men with severe OSAS (AHI≥30/h) (OR: 5.09; 95% CI: 2.67–9.71). Women with OSAS (AHI≥5/h) also had an increased risk of metabolic syndrome (OR: 6.59; 95% CI: 1.47–29.38), and the risk was significantly higher in women with severe OSAS (AHI≥30/h) (OR 14.00; 95% CI: 2.93–66.82). Risk factors for metabolic syndrome differed by gender: in men, age, body mass index (BMI), and OSAS (AHI≥15/h) were significantly associated with metabolic syndrome, whereas, in women, BMI was the only risk factor for metabolic syndrome. The increase of metabolic syndrome in Japanese OSAS patients suggests that this patient population is burdened with multiple risk factors for cardiovascular disease.

Obstructed breathing in children during sleep monitored by echocardiography

Six 3 to 14‐year‐old boys with snoring and obstructive sleep apnea syndrome were monitored polygraphically during sleep with and without nasal continuous positive airway pressure with simultaneous recording of esophageal pressure (Pes) and M‐mode and two‐dimensional echocardio‐grams. Continuous non‐invasive blood pressure monitoring was performed in two older children. Three of the six children demonstrated a diastolic leftward shift of the interventricular septum related to the negativity of Pes. Progressively more negative Pes correlated significantly with an increase in right ventricular internal end‐diastolic dimension and a decrease in left ventricular internal end‐diastolic dimension, with at times left ventricular “collapse”. One of the subjects with blood pressure monitoring demonstrated pulsus paradoxus with leftward shift of the interventricular septum. Nasal continuous positive airway pressure normalized all changes. Pulsus paradoxus and leftward shift of the interventricular septum are related to the mechanical changes associated with heavy snoring during sleep, regardless of the amount of oxygen desaturation.

Falling asleep while driving and automobile accidents among patients with obstructive sleep apnea–hypopnea syndrome

Abstract Among 448 patients with obstructive sleep apnea–hypopnea syndrome (OSAHS), 40 patients (8.9%) had been involved in one or more automobile accidents during the preceding 5 years. The main cause of these accidents was falling asleep while driving. Excessive sleepiness during driving was associated with an Epworth sleepiness scale (ESS) score of > 11 and/or an apnea–hypopnea index (AHI) of > 15. The automobile accident rate among 182 patients with severe OSAHS (AHI > 30) was significantly higher than the rate among 106 simple snorers (AHI < 5). Although four of the simple snorers were involved in automobile accidents, their ESS scores were all very high (15 or more).

Prevalence of ischemic heart disease among patients with sleep apnea syndrome

Abstract We investigated the prevalence of ischemic heart disease (IHD) in sleep apnea syndrome (SAS) and the presence of coronary risk factors involved in the onset of IHD in 386 subjects with suspected SAS due to heavy snoring. The prevalence of IHD among patients with untreated SAS was found to be 23.8%, and the percentage of patients having SAS complicated with IHD was high among those with moderate or severe SAS. Sleep apnea syndrome patients with IHD also showed high prevalences of hypertension and hyperlipidemia. It appears that sleep apnea aggravates the factors that cause coronary vascular disorders, and is involved in the onset of IHD.

Multiple cardiovascular risk factors in obstructive sleep apnea syndrome patients and an attempt at lifestyle modification using telemedicine-based education.

Severe obstructive sleep apnea syndrome (OSAS) is a typical ‘lifestyle‐related disease’ characterized by a high incidence of cardiovascular risk factors, such as obesity, smoking, hypertriglyceridemia, and diabetes mellitus. Patients with OSAS tend to have eating disorders as a result of efforts to overcome the intolerable sleepiness. Treatment of OSAS should therefore aim to improve the lifestyle through encouraging weight reduction, physical activity increase, and tobacco avoidance, in addition to direct therapy such as continuous positive airway pressure for upper airway obstruction. The telemedicine system we developed was considered to be effective for providing home‐based education on nutrition and exercise aimed at correcting multiple risk factors in OSAS patients.

Pulmonary hypertension in patients with severe obstructive sleep apnea.

Abstract Thirty‐seven patients (35 men and two women) with obstructive sleep apnea–hypopnea syndrome (OSAHS) without any known cardiovascular and lung diseases were examined by Doppler echocardiography. Eight of the 37 (21.6%) patients experienced daytime pulmonary hypertension (PH), and all of them had severe OSAHS with an apnea–hypopnea index of > 30. The study suggested that one‐third of patients with severe OSAHS had daytime PH.

Effects of physiological cardiac pacing on sleep-disordered breathing in patients with chronic bradydysrhythmias

In six patients with chronic bradydysrhythmias, polysomnographies were performed before cardiac pacemaker implantation and over the week following implantation. A patient with third‐degree atrioventricular block (AVB) and two patients with sinus node dysfunction (SND) were associated with sleep‐disordered breathing (SDB). Their cardiac pacemaker therapies, with the increase in the average heart rate, led to a reduction of apnea–hypopnea index and/or an improvement of Cheyne‐Stokes breathing. It seems that chronic bradydysrhythmia is one of the causative factors leading to SDB.

Arrhythmias in Centenarians

Background: Many studies have shown an increase in the prevalence of arrhythmias with advancing age. However, little is known about arrhythmias in centenarians. Method and Results: Thirty‐two Japanese centenarians aged 100–106 years (14 males, 18 females) were studied. All of them had 12‐lead EGGs, and 22 also had 24‐hour ambulatory monitoring. As controls, 89 healthy Japanese elderly from the same geographic area underwent 12‐lead ECG. Their mean age was 75 ± 6 years with a range of 63–93 years, and there were 28 males and 61 females. Twenty‐three of them also had Holter ECGs. On the 12‐lead ECG, the heart rate was slightly, but significantly, higher in the centenarians (76.8 ± 12.7 beats/min) than that in the elderly subjects (74.9 ± 5.9 beats/min, P < 0.005). PQ and QTC were significantly longer in the centenarians (174 ± 29 and 439 ± 33 msec, respectively) compared with the elderly subjects (158 ± 23 and 417 ± 31 msec, P < 0.005 and P < 0.001, respectively). Supraventricular premature beats (SVPBs) were observed in 31% of the centenarians and in 4% of the elderly subjects (P < 0.001). First‐ and second‐degree AV block was recorded in 25% of the centenarians and 1% of the elderly subjects (P < 0.001). Right bundle branch block was found in 19% of the centenarians and 7% of the elderly subjects (P < 0.05). There were no differences in the frequency of ventricular premature beats (VPBs) or QRS voltage. On the Holter ECG, there were no significant differences in average heart rate, maximum heart rate, minimum heart rate, or the longest RR interval. A subgroup of centenarians had frequent SVPBs. However, none of them had > 1,000 VPBs/day as opposed to four elderly subjects (P < 0.01). Atrial fibrillation was not observed in any records of the centenarians despite the presence of frequent SVPBs. Conclusion: These data suggest that conduction disturbances of the AV nodal—His‐Purkinje system and frequent SVPBs are common in centenarians, whereas very frequent VPBs and atrial fibrillation seem less common.

Aging, respiratory efforts during sleep, and pulsus paradoxus

Forty patients with either obstructive sleep apnea syndrome or a clinical complaint of daytime sleepiness with measured nocturnal increase in upper airway resistance and snoring were investigated during sleep for the presence of pulsus paradoxus, which is defined as a decrease in systolic blood pressure (SBP) of at least 10 mmHg during inspiration. Two thirds of the subjects presented pulsus paradoxus. Age, lowest oxygen saturation (SaO2), and negative inspiratory esophageal pressure nadir (an index of inspiratory effort) were the only studied variables which could statistically dissociate patients presenting pulsus paradoxus. We then divided the patient population into three different subgroups of equal number based upon the degree of decrease in SBP (i.e., >20 mmHg, <20 but >10 mmHg, and <10 mmHg). In this second analysis, age was the only significant variable that separated the three groups. Lowest SaO2 could not be used to statistically separate subjects with mild to moderate pulsus paradoxus from those without it; and negative inspiratory esophageal pressure measurements could only significantly identify subjects with severe pulsus paradoxus (i.e., >20 mmHg) from those without any pulsus paradoxus. The variable which correlated best with age was negative inspiratory esophageal pressure nadir (R = 0.83). Our interpretation is that as age increased, negative inspiratory esophagel pressure became less negative, due to the known impact of aging on muscles, and pulsus paradoxus was no longer observed.

Effective three-dimensional evaluation analysis of upper airway form during oral appliance therapy in patients with obstructive sleep apnoea

The oral appliance (OA) is considered to be an effective treatment modality for obstructive sleep apnoea (OSA). Upper airway enlargement during OA therapy is critical, and lateral cephalometry has been used for the two-dimensional evaluation of upper airway form during this therapy. However, this method cannot provide an accurate three-dimensional (3D) view of upper airway form. To confirm the effects of OA on the upper airway in patients with OSAS, we performed CT in the presence and absence of OA in 15 Japanese patients (12 males, 3 females) who responded to OA therapy. CT in the presence and absence of OA was consecutively performed for each patient, and upper airway cross-sectional area in six arbitrary planes parallel to the palatal plane was measured. Next, 3D image reconstruction was performed; morphological changes in upper airway form were evaluated, and upper airway volume at three levels from the palatal plane to the deepest point of the epiglottis was measured. The cross-sectional area of two planes in the posterior soft palate region significantly increased in the presence of OA compared with that in the absence of OA. In the presence of OA, upper airway cross-sectional area and volume significantly increased in the posterior soft palate region compared with those in the posterior tongue region. 3D CT image reconstruction accurately confirmed morphological changes in the upper airway during OA therapy. Continued use of this 3D evaluation is expected to improve the results of OA therapy in the future.