Malin Svensson

Sleep Apnea and Glucose Metabolism: A Long-term Follow-up in a Community-Based Sample

BACKGROUND It has been suggested that sleep-disordered breathing (SDB) is a risk factor for diabetes, but long-term follow-up studies are lacking. The aim of this community-based study was to analyze the influence of SDB on glucose metabolism after > 10 years. METHODS Men without diabetes (N = 141; mean age, 57.5 years) were investigated at baseline, including whole-night respiratory monitoring. After a mean period of 11 years and 4 months, they were followed up with an interview, anthropometric measurements, and blood sampling. Insulin resistance was quantified using the homeostasis model assessment of insulin resistance (HOMA-IR). ΔHOMA-IR was calculated as (HOMA-IR at follow-up − HOMA-IR at baseline). An oral glucose tolerance test was performed on 113 men to calculate the insulin sensitivity index. RESULTS The mean apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) at baseline were 4.7 and 3.3, respectively. At follow-up, 23 men had diabetes. An ODI > 5 was a predictor of developing diabetes (OR, 4.4; 95% CI, 1.1-18.1, after adjusting for age, BMI, and hypertension at baseline and ΔBMI and years with CPAP during follow-up). The ODI was inversely related to the insulin sensitivity index at follow-up (r = −0.27, P = .003). A deterioration in HOMA-IR was significantly related to all variables of SDB (AHI, AHI > 5; ODI, ODI > 5; minimum arterial oxygen saturation), even when adjusting for confounders. When excluding the variable years with CPAP from the multivariate model, all associations weakened. CONCLUSIONS SDB is independently related to the development of insulin resistance and, thereby, the risk of manifest diabetes mellitus.

Daytime Sleepiness Relates to Snoring Independent of the Apnea-Hypopnea Index in Women From the General Population

OBJECTIVES The aim was to investigate the significance of snoring and sleep apnea on daytime symptoms in a population-based sample of women. METHOD From the general population, 400 women aged 20 to 70 years were randomly selected, with oversampling of habitually snoring women. The women were investigated using full-night polysomnography and a questionnaire. The apnea-hypopnea index (AHI) was calculated, and women who acknowledged snoring loudly and disturbingly often or very often were considered habitual snorers. RESULTS Habitual snoring was independently related to excessive daytime sleepiness (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.31 to 3.99), to falling asleep involuntarily during the day (OR, 2.11; 95% CI, 1.06 to 4.21), to waking up unrefreshed (OR, 2.14; 95% CI, 1.30 to 3.52), to daytime fatigue (OR, 2.77; 95% CI, 1.54 to 4.99), and to a dry mouth on awakening (OR, 2.00; 95% CI, 1.22 to 3.27) after adjustment for AHI, age, body mass index (BMI), smoking, total sleep time, percentage of slow-wave sleep, and percentage of rapid eye movement (REM) sleep. An AHI > or = 15/h was only related to a dry mouth on awakening after adjustment for snoring, age, BMI, smoking, total sleep time, percentage of slow-wave sleep, and percentage of REM sleep (OR, 2.24; 95% CI, 1.14 to 4.40). An AHI of 5 to 15/h was not related to any daytime symptom. CONCLUSIONS Excessive daytime sleepiness and daytime fatigue are related to habitual snoring independent of the apnea-hypopnea frequency, age, obesity, smoking, and sleep parameters in a population-based sample of women, but not to the AHI. This indicates that snoring is an independent cause of excess daytime sleepiness and not merely a proxy for sleep apnea.

Relationship between sleep‐disordered breathing and markers of systemic inflammation in women from the general population

Sleep‐disordered breathing (SDB) is a risk factor for cardiovascular disease (CVD). The underlying pathogenesis is not clear. In patients with obstructive sleep apnoea syndrome (OSAS) elevated levels of inflammatory markers, such as C‐reactive protein (CRP), interleukin‐6 (IL‐6) and tumour necrosis factor α (TNFα) have been found. These markers have also been shown as independent markers of CVD in other populations. The aim of the study was to investigate the association between SDB and systemic inflammation in a population‐based cohort of women. From 6817 women who previously answered a questionnaire concerning snoring habits, 230 habitually snoring women and 170 women regardless of snoring status went through polysomnography, anthropometric measurements and blood sampling. Analyses were made for CRP, TNFα, IL‐6, myeloperoxidase (MPO) and lysozyme. The levels of CRP, IL‐6 and lysozyme were significantly higher in subjects with apnoea–hypopnoea index (AHI) ≥15 compared with women with lower AHI. All inflammatory markers except MPO correlated to AHI and oxygen desaturation measures, and to waist circumference. In multiple linear regressions adjusting for age, waist circumference and smoking, independent correlations between oxygen desaturation indices (ODI) and inflammation were found for IL‐6 (P = 0.03 for % sleep time with saturation <90%) and TNFα (P = 0.03 for ODI 3%). No significant correlations were found between AHI and inflammation. Also, for women from the general population there is an independent correlation between SDB and inflammation, even after adjusting for obesity. The results indicate that intermittent hypoxia, and not the AHI, is related to systemic inflammation seen in OSAS.

Can anatomical and functional features in the upper airways predict sleep apnea? A population-based study in females

Conclusion. The importance of clinical findings in the nose and throat, including fiberoptic endoscopy during the Muller maneuver, in predicting sleep apnea is greater in normal-weight than in overweight women. Objectives. The aim of this study was to identify clinical features that could predict sleep apnea in women. Method. From 6817 women who previously answered a questionnaire concerning snoring habits, 230 women who reported habitual snoring and 170 women from the whole cohort went through a full-night polysomnography. A nose and throat examination including fiber endoscopic evaluation of the upper airways during the Muller maneuver was performed in a random selection of 132 women aged 20–70 years. Results. Sleep apnea was defined as an apnea-hypopnea index of ≥ 10. The influence of clinical features on the prevalence of sleep apnea varied between normal-weight and overweight women. A low soft palate, retrognathia, the uvula touching the posterior pharyngeal wall in the supine position, and a 75% or more collapse at the soft palate during the Muller maneuver were all significant predictors of sleep apnea in women with a body mass index (BMI) < 25 kg/m2 but not in overweight women.

Leisure-time physical activity predicts complaints of snoring in women: a prospective cohort study over 10 years.

OBJECTIVE We aimed to assess the impact of self-reported physical activity on incidence and remission of snoring complaints in women. METHODS A population-based sample of 4851 women aged >20 years responded to questionnaires in years 2000 and 2010. Based on the responses, the women were categorized into low, medium, or high level of physical activity at baseline and at follow-up. RESULTS The prevalence of habitual snoring complaints increased from 7.6% at baseline to 9.2% in 2010 (P<.0001). After adjusting for age, body mass index (BMI), waist and neck circumference, weight gain, smoking status, alcohol dependence, and snoring status at baseline, reported physical activity level at baseline had a protective effect on habitual snoring complaints at follow-up. The adjusted odds ratio (OR) (95% confidence intervals) for complaints of habitual snoring was 0.7 (0.5-0.9) for the reported medium physical activity level and 0.5 (0.4-0.8) for the high activity level. When subdividing the population by changes in reported physical activity level over the follow-up period, an increase in physical activity was followed by a decrease in the complaint of snoring. Similarly a high level of reported physical activity only had a protective effect on snoring in participants who remained at a high or medium level. CONCLUSIONS A low level of self-reported physical activity is a risk factor for future habitual snoring complaints in women, independent of weight, weight gain, alcohol dependence, and smoking. Increased physical activity can modify the risk.

Simplified Facial Nerve Grading

Magnetoencephalography (MEG) is a useful and non-invasive method of brain mapping that has been used in many studies on evoked fields. However, there have been very few reports on magnetoencephalographic fields related with motor function. This is the first report of the recordings of magneticoencephalographic fields related with voluntary facial movement. We succeeded in recording magnetoencephalographic fields just before and during the task of lip protrusion by using a 160channel whole-head type biomagnetometer. The normal human subject repeated this task 200 times in an interval of approximately 5 seconds. In all of the 3 patients examined, equivalent current dipoles were identified initially in the nearby left primary motor area from approximately 300 ms before the initiation of the task (-300 ms). At the time of -200 ms, equivalent current dipoles (ECDs) were clearly identified in the primary motor cortex bilaterally. These results indicate that the neural activity in the primary motor cortex for lip protrusion starts not symmetrically, but asymmetrically, first in the left hemisphere and then in the right hemisphere.