Toshiki Akahoshi

The association between sleep problems and perceived health status: A Japanese nationwide general population survey

OBJECTIVE Sleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status. METHODS Cross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD). RESULTS The prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status. CONCLUSIONS This study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.

Obstructive sleep apnoea is associated with risk factors comprising the metabolic syndrome.

Background and objective:  Several features of OSA syndrome suggest that it is a manifestation of the metabolic syndrome (MS). In this study, we investigated the prevalence of the MS among male Japanese patients with OSA, as well as the relationship between OSA in non‐obese patients and components of the MS other than obesity (hypertension, dyslipidaemia and glucose intolerance).

Prevalence of chronic kidney diseases in patients with chronic obstructive pulmonary disease: assessment based on glomerular filtration rate estimated from creatinine and cystatin C levels

Background Cardiovascular diseases, osteoporosis, and depression are identified comorbidities of chronic obstructive pulmonary disease (COPD), but there have been few reports of chronic kidney disease (CKD) as a comorbidity of COPD. The objective of this study was to investigate the prevalence of CKD in COPD patients using estimated glomerular filtration rate (eGFR) based on creatinine (Cr) and cystatin C (Cys) levels. Methods The prevalence of CKD and the values of various CKD-related parameters were compared between 108 stable COPD outpatients (COPD group) and a non-COPD control group consisting of 73 patients aged 60 years or more without a history of COPD or kidney disease. CKD was defined as an eGFR less than 60 mL/min/1.73 m2. Results The Cr level was significantly higher in the COPD group, but eGFR based on serum Cr (eGFRCr) was not significantly different between the two groups (73.3±25.3 vs 79.7±15.5 mL/min/1.73 m2). The Cys level was significantly higher and eGFR based on serum Cys (eGFRCys) was significantly lower in the COPD group (60.0±19.4 vs 74.0±13.5 mL/min/1.73 m2, P<0.0001). The prevalence of CKD evaluated based on eGFRCr was 31% in the COPD group and 8% in the non-COPD group with an odds ratio of 4.91 (95% confidence interval, 1.94–12.46, P=0.0008), whereas the evaluated prevalence based on eGFRCys was 53% in the COPD group and 15% in the non-COPD group with an odds ratio of 6.30 (95% confidence interval, 2.99–13.26, P<0.0001), demonstrating a higher prevalence of CKD when based on eGFRCys rather than on eGFRCr. Conclusion CKD is a comorbidity that occurs frequently in COPD patients, and we believe that renal function in Japanese COPD patients should preferably be evaluated based not only on Cr but on Cr in combination with Cys.

Predicting optimal continuous positive airway pressure in Japanese patients with obstructive sleep apnoea syndrome

Background and objective:  Several algorithms that predict the optimal CPAP have been developed for Caucasian patients with OSA syndrome, but these algorithms do not allow for racial differences in craniofacial anatomy. We investigated whether an equation that included data on craniofacial structure, physique and severity of OSA could more accurately predict the optimal CPAP for Japanese patients with OSA syndrome.

Arrhythmia and sleep-disordered breathing in patients undergoing cardiac surgery

BACKGROUND Recently, the role of sleep-disordered breathing (SDB) in cardiovascular disease has attracted attention. In this study, we investigated the influence of SDB on postoperative arrhythmias after cardiac surgery. METHODS AND RESULTS In 89 patients undergoing cardiac surgery, postoperative portable monitoring for SDB and Holter electrocardiography were performed. The primary end-points were the apnea-hypopnea index (AHI) and occurrence of arrhythmia. The secondary end-points were: (1) patient background factors; (2) average heart rate; (3) maximum heart rate (total, daytime, and nighttime); (4) minimum heart rate (total, daytime, and nighttime); (5) minimum SaO(2) during sleep; and (6) an independent predictor for arrhythmia. Twenty-six patients (29.2%) had an AHI≥15 and they were classified into the SDB group, while patients with an AHI<15 formed the non-SDB group (70.8%). Although there was no significant difference in atrial fibrillation, frequent nocturnal premature ventricular contractions were significantly more common in the SDB group (19.2%) than the non-SDB group (3.2%) (p=0.01). Maximum daytime and nighttime heart rates were also significantly higher in the SDB group. AHI was a significant predictor for frequent nocturnal premature ventricular contractions. CONCLUSIONS This study showed that SDB is common among patients undergoing cardiac surgery, and that SDB might be closely associated with arrhythmia in these patients.

Sleep disordered breathing in cardiac surgery patients: The NU-SLEEP trial

BACKGROUND Sleep disordered breathing (SDB) is associated with lifestyle-related diseases and its treatment influence the prognosis of cardiac disease, but little investigation of SDB has been conducted in cardiac surgery patients. METHODS AND RESULTS A prospective study was performed in 1005 patients undergoing cardiac surgery. The primary endpoint was the severity of SDB determined from the apnea/hypopnea index. The secondary endpoints were patient background factors, cardiovascular risk factors, ejection fraction, atrial and brain natriuretic peptides, oxidative stress and inflammatory markers, and postoperative atrial fibrillation. While 227 patients (22.6%) did not have SDB, there were 361 patients (35.9%) with mild SDB, 260 patients (25.9%) with moderate SDB, and 157 patients (15.6%) with severe SDB. Patients with severe SDB had a lower ejection fraction and higher levels of atrial and brain natriuretic peptides than the other groups. Postoperative atrial fibrillation occurred in 28 patients without SDB (13.6%), 43 patients with mild SDB (13.5%), 74 patients with moderate SDB (31.9%), and 73 patients with severe SDB (52.5%), being significantly more frequent in the severe group than the other groups. CONCLUSIONS SDB was frequent in cardiac surgery patients. Activation of the renin-angiotensin-aldosterone system, postoperative atrial fibrillation atrial, and cardiac dysfunction were associated with severe SDB. Markers of inflammation and oxidative stress also increased as SDB became more severe.