Dr Michael Fanning
Insomnia: A sleep physician’s perspective
The next time a patient complains of insomnia, before you reach for a prescription pad to write temazepam, consider the following… apart from poor sleep hygiene and psychophysiologic insomnia (whereby the patient’s anxiety about insomnia exacerbates the insomnia), insomnia is frequently secondary to circadian rhythm disorders and sleep disordered breathing. Sorting it out requires a thorough sleep history including time to bed, sleep latency, night-time awakenings, time out of bed and details about day time naps.
A common mistake that patients make is trying to force themselves to sleep (rather than going to bed when sleepy), getting out of bed at variable times (rather than getting out of bed at the same time each day, which helps reset our ~25 hour circadian rhythm back to a 24 hour cycle) and lying in bed awake for prolonged periods (which tends to teach the body that being awake in bed is desirable).
Sleep disordered breathing such as obstructive sleep apnoea is a common cause of sleep maintenance insomnia (where the patient can’t stay asleep) and restless sleep. It is the obstructive breathing that wakes them from sleep but patients are rarely able to recall breathing difficulties.
Type 2 Diabetes
Risk of obstructive sleep apnea in patients with type 2 diabetes mellitus.
PMID: 23846968
Cass AR, Alonso WJ, Islam J, Weller SC.
University of Texas Medical Branch, Galveston, TX 77555-1123, USA. acass@utmb.edu
Fam Med. 2013 Jul-Aug;45(7):492-500.
BACKGROUND AND OBJECTIVES: Type 2 diabetes mellitus (DM) and obstructive sleep apnea (OSA) share several clinical findings: obesity, hypertension, and impaired glucose tolerance. OSA may be an under-recognized comorbidity of DM. The purpose of this study is to estimate the proportion of patients with type 2 DM at risk for OSA and describe factors associated with that risk.
METHODS: This cross-sectional study enrolled 297 adults, ages 18 years and older, with type 2 DM from a university-based Family Medicine Center. Participants completed a research questionnaire recording socio-demographic information, medical history, and clinical data including medications and hemoglobin A1C. OSA risk was determined using the Berlin Questionnaire. Relationships between risk of OSA and socio-demographic and clinical variables were evaluated using bivariate analyses and covariate adjusted logistic regression models.
RESULTS: Thirty-seven participants (12.5%) had a prior diagnosis of OSA. Based on the Berlin Questionnaire, 124 (48.6%) of the remaining patients were classified as high risk for OSA. Patients less than age 60 years were at increased risk for OSA, adjusted OR=2.67 (1.57, 4.54; 95% CI). Non-Hispanic whites, adjusted OR=1.76(1.01, 3.06; 95% CI), and patients with symptoms of depression, adjusted OR=2.64 (1.60, 4.52; 95% CI), were also at higher risk. Gender and hemoglobin A1C were not associated with increased risk of OSA.
CONCLUSION: Nearly half of adults with type 2 DM may be at high risk for OSA, and many may be undiagnosed. In a primary care setting, the Berlin Questionnaire is an easily applied screening instrument that identifies patients at increased risk of OSA who may benefit from further diagnostic studies and treatment of OSA.
OSA is associated with impaired glucose metabolism in Han Chinese subjects.
PMID: 23286469
Gu CJ, Li M, Li QY, Li N, Shi GC, Wan HY.
Shanghai Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
Chin Med J (Engl). 2013 Jan;126(1):5-10.
BACKGROUND: Increasingly, evidence from population, clinic-based and laboratory studies supports an independent association between obstructive sleep apnea syndrome (OSAS) and an increased risk of type 2 diabetes; however, this observation has yet to be replicated in China and the potential mechanisms that link these two conditions are not clear.
METHODS: A total of 179 Han Chinese subjects were enrolled in this study. All subjects underwent polysomnography, the oral glucose tolerance-insulin releasing test (OGTT-IRT) and serum HbA(1)c measurement. Indexes including homeostasis model assessment-IR (HOMA-IR), Matsuda index, HOMA-β, early phase insulinogenic index (ΔI(30)/ΔG(30)), AUC-I(180) and oral disposition index (DIo) were calculated for the assessment of insulin resistance and pancreatic β-cellfunction.
RESULTS: Based on OGTT, 25.4%, 44.6% and 54.5% subjects were diagnosed having glucose metabolic disorders respectively in control, mild to moderate and severe OSAS groups (P < 0.05). Serum HbA(1)c levels were highest in subjects with severe OSAS (P < 0.05). In contrast, compared with normal subjects, HOMA-β,ΔI(30)/Δ(G30) and DIO were lower in severe OSAS group (P < 0.05). In stepwise multiple linear regressions, 0-min glucose and HbA(1)c were positively correlated with the percentage of total sleep time below an oxyhemoglobin saturation of 90% (T90) (Beta = 0.215 and 0.368, P < 0.05); 30-min and 60-min glucose was negatively correlated with the lowest SpOO(2) (LSpO(2)) (Beta = -0.214 and-0.241, P < 0.05). HOMA-β and DI(O) were negatively correlated with T90 (Beta =-0.153 and -0.169, P < 0.05) while body mass index (BMI) was the only determinant of HOMA-IR and Matsuda index.
CONCLUSION: OSAS is associated with impairment in glucose tolerance and pancreatic β-cell function in Han Chinese subjects while insulin sensitivity is mainly determined by obesity.
Decreased nocturnal glucose variability in non-diabetic patients with sleep apnea: a pilot study.
Elizur A, Maliar A, Shpirer I, Buchs AE, Shiloah E, Rapoport MJ.
Dept of Pediatrics, Assaf Harofeh Medical Center, Sackler Faculty of Med, Tel Aviv University, Israel. elizura@gmail.com
Isr Med Assoc J. 2013 Sep;15(9):465-9.
Comment inIsr Med Assoc J. 2013 Sep;15(9):510-1.
BACKGROUND: Obstructive sleep apnea has been should be associated with impaired glucose metabolism and overt diabetes mellitus. However, the effect of hypoxic episodes on nocturnal glucose regulation in non-diabetic patients is unknown.
OBJECTIVES: To investigate the effect of hypoxemia and nocturnal glucose homeostasis in non-diabetic patients with sleep apnea.
METHODS: Seven non-diabetic patients with moderate to severe sleep apnea were connected to a continuous glucose-monitoring sensor while undergoing overnight polysomnography. Mean SpO2 and percentage of time spent at SpO2 90% were recorded. The correlation between mean glucose levels, the difference between consecutive mean glucose measurements (glucose variability) and the corresponding oxygen saturation variables were determined in each patient during REM and non-REM sleep.
RESULTS: No consistent correlation was found for the individual patient between oxygen saturation variables and glucose levels during sleep. However, a lower mean SpO2 correlated with decreased glucose variability during sleep (r = 0.79, P= 0.034). This effect was primarily evident during REM sleep in patients with significant, compared to those with mild, oxygen desaturations during sleep (>30% vs. < 10% of sleeping time spent with SpO2 < 90%) (P = 0.03).
CONCLUSION: Severe nocturnal hypoxemia in non-diabetic patients with moderate to severe sleep apnea might affect glucose regulation primarily during REM sleep.
Hypertension
Predictors of blood pressure reduction with nocturnal CPAP therapy in patients with OSA and prehypertension.
PMID: 23427278
Yorgun H, Kabakçi G, Canpolat U, Kirmizigül E, Sahiner L, Ates AH, Sendur MA, et al
Department of Cardiology, Hacettepe University, Ankara, Turkey.
Comment in Angiology. 2014 Feb;65(2):93-4.
Angiology. 2014 Feb;65(2):98-103
Previous studies showed that treatment of obstructive sleep apnea syndrome (OSAS) with continuous positive airway pressure (CPAP) significantly reduced the blood pressure (BP) in hypertensive patients. We investigated the predictors of BP change in normotensive patients with OSAS who underwent CPAP. A total of 24patients with OSAS (19 male; age: 48.7 ± 10.4 years) were enrolled. The 24-hour mean BP (24 hMBP), subjective sleepiness, fasting venous blood samples, and anthropometric measurements were assessed at baseline, 6th week and 12th week of CPAP treatment. The 24 hMBP fell at 12 weeks from 89.2 ± 8.4 to 82.9 ± 7.3 mm Hg (P < .0001) irrespective of the severity of disease. Also, both daytime and nighttime BP showed significant reduction after CPAP. Male gender, Epworthsleepiness scale, body mass index, smoking, alcohol use, and baseline 24 hMPB were the independent predictors of a fall in 24 hMBP.
CONCLUSION: CPAP therapy may provide benefit even in the absence of overt hypertension by reducing both daytime and nighttime BP.
The relationship between morning hypertension and sleep quality in patients with OSAS.
PMID: 23530964
Sasaki N, Ozono R, Yamauchi R, Teramen K, Edahiro Y, Ishii K, Seto A, Kihara Y.
Department of Internal Medicine, Mitsubishi Mihara Hospital, Mihara, Japan. fm2khdz3@384.jp
Clin Exp Hypertens. 2013;35(4):250-6.
This study aimed to investigate the prevalence of abnormal diurnal blood pressure(BP) profiles in patients with obstructive sleep apnea syndrome (OSAS) in relation to the data of a sleep study. Total 103 patients newly diagnosed with OSAS underwent overnight polysomnography and 24-hour ambulatory BP measurements. Patients without morning or nocturnal hypertension (control group), patients with morning hypertension but not nocturnal hypertension (surge-type group), and patients with both morning and nocturnal hypertension (sustained-type group) were compared. Morning hypertension was present in 54 patients (16 surge-type and 38sustained-type). The apnea-hypopnea index and sleep efficiency were higher and lower, respectively, in the sustained-type group than in the other groups. Slow-wave sleep incidence was significantly lower in the sustained-type and surge-type groups than in the control group.
CONCLUSION: These results suggest that approximately half the OSAS patients displayed morning hypertension, the sustained-type being more common than the surge-type. Poor sleep quality plays an important role in the pathogenesis of morning hypertension in both the sustained-and the surge-type group.
Gastro-oesophageal Reflux (GOR)
Nocturnal gastro-oesophageal reflux, asthma and symptoms of OSA: a longitudinal, general population study.
PMID: 23018910
Emilsson ÖI, Bengtsson A, Franklin KA, Torén K, Benediktsdóttir B, Farkhooy A, Weyler J, Dom S, De Backer W, et al.
Faculty of Medicine, University of Iceland, Landspitali University Hospital, Reykjavik, Iceland. ossuri@landspitali.is
Eur Respir J. 2013 Jun;41(6):1347-54.
Nocturnal gastro-oesophageal reflux (nGOR) is associated with asthma and obstructive sleep apnoea (OSA). Our aim was to investigate whether nGOR is a risk factor for onset of asthma and onset of respiratory and OSA symptoms in a prospective population-based study. We invited 2640 subjects from Iceland, Sweden and Belgium for two evaluations over a 9-year interval. They participated in structured interviews, answered questionnaires, and underwent spirometries and methacholine challenge testing. nGOR was defined by reported symptoms. Subjects with persistent nGOR (n=123) had an independent increased risk of new asthma at follow-up (OR 2.3, 95% CI 1.1-4.9). Persistent nGOR was independently related to onset of respiratory symptoms (OR 3.0, 95% CI 1.6-5.6). The risk of developing symptoms of OSA was increased in subjects with new and persistent nGOR (OR 2.2,95% CI 1.3-1.6, and OR 2.0, 95% CI 1.0-3.7, respectively).
CONCLUSION: No significant association was found between nGOR and lung function or bronchial responsiveness. Persistent symptoms of nGOR contribute to the development of asthma andrespiratory symptoms. New onset of OSA symptoms is higher among subjects with symptoms of nGOR. These findings provide evidence that nGOR may play a role in the genesis of respiratory symptoms and diseases.
Nocturnal gastro-oesophageal reflux and sleep apnea: what relationship?
Emilsson ÖI, Bengtsson A, Franklin KA, Torén K, Benediktsdóttir B, Farkhooy A, Weyler J, Reflux gastro-oesophagien nocturne et syndrome d’apnees du sommeil : Quelles relations ?
Romdhane Hayfa; Ben Abdallah Hatem; Abdelli Mohamed Nabil
Hospital militaire principal d’instruction de Tunis, Universitd Tunis-El Manar, Tunisie.
La Tunisie medicale ( Tunisia ) Aug-Sep 2012 , 90 (8-9) p598-601
BACKGROUND: Gastro-oesophageal reflux disease and nocturnal sleep disturbances are frequently encountered in clinical practice and are often associated. However, the combination of these two syndromes does not necessarily imply a cause and effect. In a more precise, the relationship between nocturnal gastro-oesophageal reflux and sleep apnea syndrome has been debated since even if their respective prevalences are high in the presence of one or the other syndrome, it is difficult to eliminate mutual induction.
AIM: To determine the pathophysiological relations, the frequency of the association between nocturnal gastro-oesophageal reflux and sleep apnea syndrome and the impact of specific therapies to each of these two syndromes on the other. METHODS: Review of the literature.
RESULTS: On the relationship between these two entities, it seems obvious that nocturnal gastro-oesophageal reflux affects the normal physiology of sleep and alters its quality and that the sleep apnea syndrome can aggravate reflux. On the frequency of their association, gastro-oesophageal reflux was observed in the presence of sleep apnea syndrome; in 27 to 75% of patients in studies that do not include pH-metric and polysomnographic recording simultaneously. Regarding treatment, continuous positive airway pressure seems to improve night time gastro-oesophageal reflux both in terms of symptoms that pH-metric results. Similarly, inhibitors of proton pump inhibitors have demonstrated their effectiveness in combination with specific treatment, in improving symptoms caused by sleep apnea syndrome.
CONCLUSION: we can confirm that there is a strong link between nocturnal gastro-oesophageal reflux and sleep apnea syndrome but causality is hard to be confirmed. Moreover, it seems useful to look for sleep disorders in patients with nocturnal gastro-oesophageal reflux also to suggest the diagnosis of gastro-oesophageal reflux in patients with sleep apnea syndrome.
Depression
Obstructive sleep apnea and the subsequent risk of depressive disorder: a population-based follow-up study.
Chen YH, Keller JK, Kang JH, Hsieh HJ, Lin HC.
School of Public Health, Taipei Medical University, Taipei, Taiwan.
J Clin Sleep Med. 2013 May 15;9(5):417-23.
Comment in J Clin Sleep Med. 2013 May 15;9(5):425-6.
STUDY OBJECTIVES: Empirical findings on the prospective link between obstructive sleep apnea (OSA) and subsequent depression are mixed. This nationwide, population-based study thus aimed at assessing the risk of depressive disorder within the first year following a diagnosis with OSA. Gender effects were further examined.
DESIGN: Cohort study.
SETTING: Taiwan.
PATIENTS: This study used data from the Longitudinal Health Insurance Database2000. A total of 2,818 patients diagnosed with OSA between 2002 and 2008 were evaluated, and 14,090 matched non-OSA enrolees used as a comparison cohort.
MEASUREMENTS AND RESULTS: Each patient was followed for one year to identify subsequent depressive disorder. We found that during the one-year follow-up, the incidence of depressive disorder per thousand person-years was about twice as high among patients with OSA (18.10, 95% CI = 13.62-23.61) as those without OSA(8.23, 95% CI = 6.83-9.84). The Cox proportional hazards model revealed that patients with OSA were independently associated with a 2.18 times (95% CI =1.55-3.08) increased risk of subsequent depressive disorder within a year, compared to those without OSA. As epidemiological studies have consistently documented an increased risk for depression in women, we hypothesized and confirmed higher risks of depressive disorder among female patients with OSA(2.72, 95% CI = 1.68-4.40) than their male counterparts (1.81, 95% CI =1.09-3.01).
CONCLUSION: A prospective link between OSA and subsequent depressive disorder within one year was confirmed by the current study. The risk was particularly evident among women. Regular psychiatric screening among patients with OSA is suggested to prompt the timely detection of depression.
Image attributions:
“Diabetic Lancet Device In Hand” Image courtesy of pat138241 / FreeDigitalPhotos.net
“Doctor Measuring Blood Pressure” Image courtesy of Ambro / FreeDigitalPhotos.net
