Increasing systemic chronic inflammation mediated the association between poor sleep during pregnancy and gestational cardiovascular health

OBJECTIVES

This study aimed to examine the association between sleep behaviors and cardiovascular health (CVH) during pregnancy and test whether high-sensitivity C-reactive protein (hs-CRP) mediates this association.

METHODS

The study included 4204 pregnant women from the Maternal and Infant Health cohort study in Hefei (MIH-Hefei). Information on sleep (chronotype, sleep duration, snoring, daytime sleepiness, and insomnia) was collected through a touch-screen structured questionnaire at 16-23 weeks' gestation. CVH (body mass index, blood pressure, total cholesterol, glucose, and smoking) and hs-CRP were measured at 24-28 weeks' gestation. The role of hs-CRP in the association between sleep and CVH was explored in a mediation analysis, while adjusting for multiple confounding factors.

RESULTS

Poor sleep score was significantly associated with poor gestational CVH metrics, including an RR of 0.872 (95% CI, 0.810, 0.938) for having all ideal (vs. any nonideal) CVH metrics; hs-CRP level was significantly associated with poor gestational CVH metrics, including an RR of 0.531 (95% CI, 0.432, 0.609) for having all ideal (vs. any nonideal) CVH metrics. Sleep scores were positively correlated with hs-CRP level (β, 0.020, 95% CI, 0.006, 0.034). Mediation analysis revealed that the association between sleep and CVH mediated by hs-CRP was 12.31% (indirect effect, -0.0095, 95% CI, -0.0167, -0.0042).

CONCLUSIONS

Poor sleep during pregnancy, particularly late chronotype and snoring, may worsen CVH by increasing systemic chronic inflammation.

Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events (i.e., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE.

Self-reported sleep duration and napping, cardiac risk factors and markers of subclinical vascular disease: cross-sectional study in older men

STUDYOBJECTIVES

Daytime sleep has been associated with increased risk of cardiovascular disease and heart failure (HF), but the mechanisms remain unclear. We have investigated the association between daytime and night-time sleep patterns and cardiovascular risk markers in older adults including cardiac markers and subclinical markers of atherosclerosis (arterial stiffness and carotid intima-media thickness (CIMT)).

METHODS

Cross-sectional study of 1722 surviving men aged 71-92 examined in 2010-2012 across 24 British towns from a prospective study initiated in 1978-1980. Participants completed a questionnaire and were invited for a physical examination. Men with a history of heart attack or HF (n=251) were excluded from the analysis.

RESULTS

Self-reported daytime sleep duration was associated with higher fasting glucose and insulin levels (p=0.02 and p=0.01, respectively) even after adjustment for age, body mass index, physical activity and social class. Compared with those with no daytime sleep, men with daytime sleep >1 hour, defined as excessive daytime sleepiness (EDS), had a higher risk of raised N-terminal pro-brain natriuretic peptide of ≥400 pg/mL, the diagnostic threshold for HF (OR (95% CI)=1.88 (1.15 to 3.1)), higher mean troponin, reduced lung function (forced expiratory volume in 1 s) and elevated von Willebrand factor, a marker of endothelial dysfunction. However, EDS was unrelated to CIMT and arterial stiffness. By contrast, night-time sleep was only associated with HbA1c (short or long sleep) and arterial stiffness (short sleep).

CONCLUSIONS

Daytime sleep duration of >1 hour may be an early indicator of HF.

Sleep duration and quality, and risk of gestational diabetes mellitus in pregnant Chinese women

AIMS

To examine the association between sleep disturbances during pregnancy and risk of gestational diabetes mellitus.

METHODS

From 2010 to 2012, 12 506 women in Tianjin, China, were screened using a 50-g 1-h glucose challenge test at 24-28 weeks' gestation. Those with glucose challenge test values of ≥ 7.8 mmol/l were invited to further undergo a 75-g 2-h oral glucose tolerance test. Gestational diabetes was determined according to the International Association of Diabetes and Pregnancy Study Group's definition. Self-reported sleep duration and sleep quality during pregnancy was documented using a modified questionnaire. Logistic regression was used to obtain odds ratios and 95% CIs.

RESULTS

A total of 919 women (7.3%) had gestational diabetes. Sleep duration was found to have an approximate J-shaped association with gestational diabetes risk after adjusting for covariates. Compared with a sleep duration of 7-9 h/day (43% of 12 506 women), the adjusted odds ratios for sleep duration of ≥ 9 h/day (55%) and < 7 h/day (2%) for gestational diabetes were 1.21 (95% CI 1.03-1.42) and 1.36 (95% CI 0.87-2.14), respectively. Compared with good sleep quality (37.9% of 12 506 women), the adjusted odds ratios of moderate (59.9%) and poor sleep quality (2.2%) for gestational diabetes were 1.19 (95% CI 1.01-1.41) and 1.61 (95% CI 1.04-2.50), respectively.

CONCLUSION

In pregnant Chinese women, poor sleep quality, and shorter and longer duration of sleep during pregnancy were independently associated with an increased risk of gestational diabetes.

Daytime sleepiness is associated with hyperhomocysteinemia in rural area of China: A cross-sectional study

OBJECTIVE

To ascertain whether sleep abnormalities including daytime sleepiness, snoring, apnea, sleep disruption and sleep duration abnormity are significantly associated with hyperhomocysteinemia (Hhcy).

METHODS

A total of 5992 participants were involved in the cross-sectional study. Sleep abnormalities were evaluated by a structured questionnaire. Hhcy was defined as plasma levels of homocysteine ≥15μm/L.

RESULTS

After adjustment for age, gender, education, current smoking status and current drinking status, daytime sleepiness (OR, 1.597; 95%CI, 1.210-2.110, P=0.001), sleep duration <6h (OR, 1.273; 95%CI, 1.063-1.524, P=0.009) and sleep duration >8h (OR, 1.205; 95%CI, 1.065-1.364, P=0.003) were significantly associated with Hhcy. While snoring (OR, 1.065; 95%CI, 0.950-1.195, P=0.279), apnea (OR, 1.170; 95%CI, 0.924-1.482, P=0.193), and sleep disruption (OR, 1.065; 95%CI, 0.852-1.331, P=0.580) were not. After further adjustment for body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, total cholesterol, physical activity, diabetes, coronary heart disease, stroke, depression, glomerular filtration rate, hypertension and hyperuricemia, still the increased OR could be found in the daytime sleepiness group (OR, 1.569; 95%CI, 1.145-2.150, P=0.005). However, sleep duration <6h (OR, 1.067; 95%CI, 0.788-1.445, P=0.676) and sleep duration >8h groups (OR, 1.080; 95%CI, 0.883-1.320, P=0.453) were no longer significantly associated with Hhcy.

CONCLUSIONS

Daytime sleepiness, but not sleep duration abnormity, snoring, apnea and sleep disruption was an independent risk factor for Hhcy.

Sleepiness, inflammation and oxidative stress markers in middle-aged males with obstructive sleep apnea without metabolic syndrome: a cross-sectional study

BACKGROUND

The simultaneous occurrence of metabolic syndrome and excessive daytime sleepiness are very common in obstructive sleep apnea (OSA) patients. Both conditions, if present in OSA, have been reported to be associated with inflammation and disruption of oxidative stress balance that impair the cardiovascular system. To verify the impact of daytime sleepiness on inflammatory and oxidative stress markers, we evaluated OSA patients without significant metabolic disturbance.

METHODS

Thirty-five male subjects without diagnostic criteria for metabolic syndrome (Adult Treatment Panel III) were distributed into a control group (n = 10) (43 ± 10.56 years, apnea-hypopnea index - AHI 2.71 ± 1.48/hour), a non-sleepy OSA group (n = 11) (42.36 ± 9.48 years, AHI 29.48 ± 22.83/hour) and a sleepy OSA group (n = 14) (45.43 ± 10.06 years, AHI 38.20 ± 25.54/hour). Excessive daytime sleepiness was considered when Epworth sleepiness scale score was ≥ 10. Levels of high-sensitivity C-reactive protein, homocysteine and cysteine, and paraoxonase-1 activity and arylesterase activity of paraoxonase-1 were evaluated.

RESULTS

Patients with OSA and excessive daytime sleepiness presented increased high-sensitivity C-reactive protein levels even after controlling for confounders. No significant differences were found among the groups in paraoxonase-1 activity nor arylesterase activity of paraoxonase-1. AHI was independently associated and excessive daytime sleepiness tended to have an association with high-sensitivity C-reactive protein.

CONCLUSIONS

In the absence of metabolic syndrome, increased inflammatory response was associated with AHI and daytime sleepiness, while OSA was not associated with abnormalities in oxidative stress markers.

Effect of continuous positive airway pressure therapy on sexual function and serum testosterone in males with type 2 diabetes and obstructive sleep apnoea

OBJECTIVE

There have been no studies of the effect of continuous positive airway pressure (CPAP) therapy on erectile dysfunction (ED) and serum testosterone in men with type 2 diabetes and obstructive sleep apnoea (OSA), a patient group at increased risk of ED and hypogonadism. The aim of this study was to determine whether CPAP improves sexual and gonadal function in males with type 2 diabetes and a pre-CPAP apnoea-hypopnoea index >15/h.

DESIGN

Substudy of a trial assessing the effect of 3 months of CPAP on cardiovascular risk in type 2 diabetes.

PATIENTS

Of 35 males starting CPAP, 27 (mean ± SD age 65.4 ± 9.6 years, median [interquartile range] diabetes duration 12.1 [5.2-15.3] years) completed the trial.

MEASUREMENTS

Serum total and free testosterone, responses to the Androgen Deficiency in the Aging Aale (ADAM) and Sexual Health Inventory for Men (SHIM) questionnaires.

RESULTS

There were no significant changes in mean total or free testosterone (baseline concentrations 12.7 ± 4.5 nm and 0.26 ± 0.07 pm, respectively), or SHIM score (baseline 13 [5-17]), after 3 months of CPAP (P > 0.20). The ADAM score (baseline 6.2 ± 2.1) fell after 1 month (to 5.0 ± 2.6) and was maintained at this level at 3 months (P = 0.015). The Epworth Sleepiness Scale score decreased and self-reported physical activity increased over 3 months (P ≤ 0.017) without a change in body mass index (P = 1.00).

CONCLUSIONS

These findings imply that CPAP therapy improves somnolence and promotes exercise in men with type 2 diabetes, but that there is no direct benefit for gonadal or sexual function.

Sleep-wake and melatonin pattern in craniopharyngioma patients

OBJECTIVE

To assess the influence of craniopharyngioma or consequent surgery on melatonin secretion, and the association with fatigue, sleepiness, sleep pattern and sleep quality.

DESIGN

Cross-sectional study.

METHODS

A total of 15 craniopharyngioma patients were individually matched to healthy controls. In this study, 24-h salivary melatonin and cortisol were measured. Sleep-wake patterns were characterised by actigraphy and sleep diaries recorded for 2 weeks. Sleepiness, fatigue, sleep quality and general health were assessed by Multidimensional Fatigue Inventory, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Short-Form 36.

RESULTS

Patients had increased mental fatigue, daytime dysfunction, sleep latency and lower general health (all, P≤0.05), and they tended to have increased daytime sleepiness, general fatigue and impaired sleep quality compared with controls. The degree of hypothalamic injury was associated with an increased BMI and lower mental health (P=0.01). High BMI was associated with increased daytime sleepiness, daytime dysfunction, mental fatigue and lower mental health (all, P≤0.01). Low midnight melatonin was associated with reduced sleep time and efficiency (P≤0.03) and a tendency for increased sleepiness, impaired sleep quality and physical health. Midnight melatonin remained independently related to sleep time after adjustment for cortisol. Three different patterns of melatonin profiles were observed; normal (n=6), absent midnight peak (n=6) and phase-shifted peak (n=2). Only patients with absent midnight peak had impaired sleep quality, increased daytime sleepiness and general and mental fatigue.

CONCLUSION

Craniopharyngioma patients present with changes in circadian pattern and daytime symptoms, which may be due to the influence of the craniopharyngioma or its treatment on the hypothalamic circadian and sleep regulatory nuclei.

The impact of sleep deprivation on sleepiness, risk factors and professional performance in medical residents

BACKGROUND

Prolonged working hours and sleep deprivation can exert negative effects on professional performance and health.

OBJECTIVES

To assess the relationship between sleep deprivation, key metabolic markers, and professional performance in medical residents.

METHODS

We compared 35 residents working the in-house night shift with 35 senior year medical students in a cross-sectional cohort study. The Epworth Sleepiness Scale (ESS) questionnaire was administered and blood tests for complete blood count (CBC), blood chemistry panel, lipid profile and C-reactive protein (CRP) were obtained from all participants.

RESULTS

Medical students and medical residents were comparable demographically except for age, weekly working hours, reported weight gain, and physical activity. The ESS questionnaires indicated a significantly higher and abnormal mean score and higher risk of falling asleep during five of eight daily activities among medical residents as compared with medical students. Medical residents had lower high density lipoprotein levels, a trend towards higher triglyceride levels and higher monocyte count than did medical students. CRP levels and other laboratory tests were normal and similar in both groups. Among the residents, 5 (15%) were involved in a car accident during residency, and 63% and 49% reported low professional performance and judgment levels after the night shift, respectively.

CONCLUSIONS

Medical residency service was associated with increased sleepiness, deleterious lifestyle changes, poorer lipid profile, mild CBC changes, and reduced professional performance and judgment after working the night shift. However, no significant changes were observed in CRP or in blood chemistry panel. Larger prospective cohort studies are warranted to evaluate the dynamics in sleepiness and metabolic factors overtime.

Association between excessive daytime sleepiness and severe hypoglycemia in people with type 2 diabetes: the Edinburgh Type 2 Diabetes Study

OBJECTIVE

Sleep-disordered breathing and sleepiness cause metabolic, cognitive, and behavioral disturbance. Sleep-disordered breathing is common in type 2 diabetes, a condition that requires adherence to complex dietary, behavioral, and drug treatment regimens. Hypoglycemia is an important side effect of treatment, causing physical and psychological harm and limiting ability to achieve optimal glycemic control. We hypothesized that sleep disorder might increase the risk of hypoglycemia through effects on self-management and glucose regulation.

RESEARCH DESIGN AND METHODS

People with type 2 diabetes (n = 898) completed questionnaires to assess sleep-disordered breathing, daytime sleepiness, and occurrence of severe hypoglycemia.

RESULTS

Subjects who scored highly on the Epworth Sleepiness Scale were significantly more likely to have suffered from severe hypoglycemia. This was a significant predictor of severe hypoglycemia in regression analysis including the variables age, sex, duration of diabetes, HbA1c, BMI, and treatment type.

CONCLUSIONS

Daytime sleepiness may be a novel risk factor for hypoglycemia.

[The study on AHI, LSaO2 and ET-1 in patients with obstructive sleep apnea-hypopnea syndrome after H-UPPP]

OBJECTIVE

To explore the treatment effect of H-UPPP on patients with obstructive sleep apnea hypopnea syndrome (OSAHS).

METHOD

Seventy-nine patients were enrolled in our study. Among which 49 patients were done with H-UPPP, and the other 30 patients were done with UPPP. AHI and LSaO2 were monitored by polysomnography and plasma endothelins-1 were tested with enzyme linked immunosorbent assay (ELISA) before and after operation.

RESULT

Forty-one patients were improved with reduced snoring and daytime sleepiness one year after operation in H-UPPP group,and the overall efficiency was 83.7%. Twenty-six patients were improved with reduced snoring and daytime sleepiness one year after operation in UPPP group, and the overall efficiency was 86.7%. There were significant differences of AHI, LSaO2 and ET-1 before and after operation between the two groups. Negative correlation was showed between AHI and LSaO2, also between LSaO2 and ET-1.

CONCLUSION

Both H-UPPP and UPPP were proved to be effective to patients with OSAHS. The perioperative complications with H-UPPP was less than UPPP.

Endothelial function in patients with post-CPAP residual sleepiness

STUDY OBJECTIVES

The significance of residual excessive daytime sleepiness (EDS) on cardiovascular markers in patients with adequately treated obstructive sleep apnea (OSA) remains unclear. The objective of this study was to investigate flow-mediated dilatation (FMD) and inflammatory markers (C-reactive protein [CRP], tumor necrosis factor [TNF]-alpha, and interleukin [IL]-6) in continuous positive airway pressure (CPAP)-compliant patients with residual EDS compared with CPAP-compliant patients without residual EDS.

METHODS

FMD of the brachial artery was measured by ultrasound in 12 CPAP-compliant patients with OSA who had residual EDS and 12 age-, sex-, and body mass index-matched CPAP-compliant patients with OSA who did not have residual EDS on week 8 after initiation of CPAP. Twelve otherwise-healthy subjects without sleep disordered breathing were used as control subjects. Serum concentrations of CRP, TNF-alpha, and IL-6 were quantified by enzyme-linked immunosorbent assays.

RESULTS

Baseline FMD was comparable among CPAP-compliant patients with residual EDS (7.2 +/- 2.3), CPAP-compliant patients without residual EDS (8.6 +/- 2.1), and control subjects (7.7 +/- 1.4) (p = 0.37). The concentrations of CRP, TNF-alpha, and IL-6 were also not significantly different between subjects with CPAP-compliant residual EDS and those without residual EDS (p = 0.44, p = 0.37, and p = 0.42; respectively).

CONCLUSIONS

Residual EDS in patients with adequately treated OSA may not represent a risk factor for cardiovascular diseases.

Iron stores, periodic leg movements, and sleepiness in obstructive sleep apnea

STUDY OBJECTIVES

Most clinical sleep studies are performed for suspected obstructive sleep apnea (OSA), yet one-quarter to one-half show periodic leg movements (PLMs), for reasons that remain unknown. Several other disparate sleep disorders also increase the risk for PLMs. We examined the novel hypotheses that OSA as a representative sleep disorder could promote lower body iron stores, as reflected by serum ferritin levels, and, through downstream effects on dopaminergic transmission, increase PLMs and daytime sleepiness.

METHODS

Subjects were recruited as they underwent laboratory-based polysomnography for suspected OSA. Serum ferritin levels were measured the next morning. Each subject completed an Epworth Sleepiness Scale and a brief questionnaire to assess for restless legs syndrome (RLS).

RESULTS

The frequency of apneic events showed no association with serum ferritin levels, before or after adjustment for age, sex, body mass index, and likely RLS (each p value > 0.3). Serum ferritin levels did not predict the frequency of PLMs (p = 0.7) or Epworth scores (p = 0.8). Iron deficiency as a dichotomous variable, determined by ferritin levels less than < 50 microg/L or in combination with low transferrin saturation or mean corpuscular volume, showed similar results. In exploratory analyses, contrary to expectations, lower minimum oxygen saturation and increased sleep-stage shifts predicted increased rather than decreased ferritin levels (p = 0.03 and p = 0.02, respectively).

CONCLUSIONS

Results of this study, powered to detect small to moderate effect sizes, strongly suggest that OSA does not cause lower serum ferritin levels, which, in turn, cannot explain PLMs or daytime sleepiness in these patients.

Forty- versus 20-minute trials of the maintenance of wakefulness test regimen for licensing of drivers

STUDY OBJECTIVES

Objective assessment of the ability to maintain wakefulness, although very important, is still equivocal. A recent study from our lab has shown that the Maintenance of Wakefulness Test (MWT), when performed with the 20-minute protocol (MWT20), is unreliable in assessing patients who are highly motivated to maintain wakefulness. In this study, we sought to examine whether the 40-minute protocol (MWT40) is a better tool in assessing such individuals.

METHODS

One hundred sixty-four consecutive subjects referred to our sleep lab by the Medical Institute for Driving Safety were studied. All subjects underwent a full-night polysomnogram followed by an MWT, 4 trials of 40 minutes each. All subjects knew that if they failed the wakefulness test their driving license would be revoked.

RESULTS

Forty-one subjects out of 164 (25%) fell asleep at least once. Of 39 subjects with severe obstructive sleep apnea, (respiratory disturbance index > 40/h), 19 fell asleep (48.7%). Of 13 subjects with a minimum oxygen saturation level below 65%, 7 fell asleep (53%). In the MWT20, only 7% of patients with severe obstructive sleep apnea fell asleep at least once.

CONCLUSIONS

We conclude that the MWT40 is superior to the MWT20 in detecting difficulties maintaining wakefulness in a highly motivated population. However, our results yield a significantly lower detection of difficulties maintaining wakefulness than those reported in healthy subjects, suggesting that the MWT40 is also highly affected by motivation. We believe that, for a highly motivated population (such as for a driver's license validation), different average sleep-latency threshold should be used than in general population.

[Association between residual sleepiness and central sleep apnea events in patients with obstructive sleep apnea syndrome]

OBJECTIVE

To investigate the possible association between residual sleepiness (RS) and central sleep apnea events in patients with obstructive sleep apnea syndrome (OSAS) following continuous positive airway pressure (CPAP) treatment, as well as the effects of adaptive servo-ventilation (ASV) on RS.

METHODS

Following correct application of CPAP treatment and exclusion of other sleepiness-associated disorders, 50 patients with moderate-to-severe OSAS were recruited, including 26 patients with RS (RS group) and 24 patients without RS (control group). The treatment of one month's auto-CPAP (AutoCPAP) followed by one week ASV with autoCS2 ventilator was performed. Comparisons were made separately before treatment, on AutoCPAP and ASV treatments in both groups of the following parameters: polysomnographic parameters including central sleep apnea index (CSAI), micro-arousal index (MAI), etc; daytime Epworth sleepiness score (ESS), and possibly sleepiness-associated factor, i.e., plasma tumor necrosis factor-alpha (TNF-alpha). Plasma TNF-alpha levels were measured by enzyme linked immunosorbent assay (ELISA). t test and single factor analysis of variances were used for comparison between two groups and within group respectively. q test was used for couple comparison within group at 3 different stages. Pearson correlation test was performed for correlation analysis between 2 variables.

RESULTS

Before treatment there was no significant difference between two groups in apnea hypopnea index (AHI), MAI, minimal pulse oxygen saturation (minSpO2), ESS and plasma TNF-alpha levels (t: 0.630, 1.223, 0.691, 0.764 and 0.19 2, all P > 0.05). However, the CSAI in RS group was significantly higher than that in the control group [(7.19 +/- 1.75) times/h vs (3.37 +/- 1.04) times/h, t = 4.097, P < 0.05)]. After 1 month's AutoCPAP treatment there was a significant decrease in AHI, CSAI, MAI and ESS in both groups (q: 0.87-112.55, all P < 0.05), but CSAI, MAI and ESS in the RS group than those in the control group [CSAI: (7.19 +/- 1.75) times/h vs (3.37 +/- 1.04) times/h, t = 9.473, P < 0.05; MAI: (9.00 +/- 1.95) times/h vs (2.36 +/- 0.66) times/h, t = 14.385, P < 0.05; ESS: 9.54 +/- 0.51 vs 5.42 +/- 1.32, t = 2.857, P < 0.05). On one weeks' ASV treatment there was such a further significant decrease in CSAI, MAI and daytime ESS in the RS group and the control group. In addition, compared with the plasma TNF-alpha level before treatment in the RS group, there was no statistical difference on AutoCPAP treatment but a significant decrease on ASV treatment. Plasma TNF-alpha levels were positively correlated with ESS (r = 0.503, P < 0.01) and MAI (r = 0.545, P < 0.01).

CONCLUSIONS

RS in OSAS patients following CPAP treatment was associated with their CSAI before and during treatment. By effectively eliminating CSA events with ASV, RS was significantly improved, which suggested that ASV was effective in treatment of RS. The elevation of plasma TNF-alpha level was correlated with the severity of sleepiness and may be involved in the pathogenesis of RS.

Association between serum neopterin, obesity and daytime sleepiness in patients with obstructive sleep apnea

OBJECTIVE

Obesity and obstructive sleep apnea (OSA) and systemic inflammation may interact through biochemical pathways. Neopterin (NP) is a monocyte/macrophage activation marker produced by macrophages in response to interferon-gamma secreted by activated T-lymphocytes. This study examines the association between NP, obesity and OSA.

PATIENTS AND METHODS

The study included 22 newly diagnosed OSA (+) patients and 18 OSA (-) patients. Subjects with history of coronary artery disease, transplant patients, history of alcohol and drug abuse, history of HIV and any other significant medical illnesses such as active infections, autoimmune disease, malignancy, liver disease, pulmonary disease (COPD, asthma,...), neuromuscular disease, patients on immunomodulating therapy or HMG-CoA reductase inhibitors were excluded.

RESULTS

There were no significant differences in age, body mass index (BMI), and smoking habits of the OSA (+) patients and OSA (-) patients. Serum NP levels did not show any significant difference between the OSA (+) patients and OSA (-) patients, however, NP levels were positively correlated with BMI (r=0.320, p=0.044). There was no significant correlation between NP and any of the polysomnographic parameters. The result of stepwise regression analyses (r(2)=0.320, p<0.001) showed that high serum NP levels (p=0.004) and apnea-hypopnea index (AHI) were a risk factor for elevated Epworth sleepiness score, independent of BMI.

CONCLUSION

We suggest that serum NP levels correlate with BMI. There was a significant relationship between serum NP levels and excessive daytime sleepiness in OSA patients.

A comparison of glycemic control, sleep, fatigue, and depression in type 2 diabetes with and without restless legs syndrome

OBJECTIVE

The purpose of this pilot study was to determine how sleep quality, glycemic control, sleepiness, fatigue, and depression differ in persons with type 2 diabetes with and without restless legs syndrome (RLS). RESEARCH DESIGNS/METHODS: The design was a descriptive, case-control study of participants with type 2 diabetes with and without RLS at the University of Pennsylvania, Rodebaugh Diabetes Center. Thirty-nine participants (adults over 21 years of age who had been diagnosed with type 2 diabetes and had a HbA1c in the last 3 months) were stratified based on RLS diagnostic criteria. Exclusion criteria included severe hypoglycemia identified by seizures or coma related to hypoglycemia or known sleep disorder other than RLS. The primary outcome of sleep was measured by self-report sleep quality (Pittsburgh Sleep Quality Index) with secondary outcomes including HbA1c, sleepiness (Epworth Sleepiness Scale), fatigue (Fatigue Severity Scale), and depression (Center for Epidemiologic Studies-Depression Scale).

RESULTS

Participants with type 2 diabetes with RLS reported a significant difference in quality of sleep (p = .001), sleep latency (p = .04), sleep efficiency (p = .035), use of sleep medications (p < .001), and daytime dysfunction (p = .005). In the total group, higher HbA1c levels were positively correlated with sleepiness (p = 038). Global Pittsburgh Sleep Quality Index scores were positively correlated with fatigue (r = .58, p = .002) and depression (r =.74, p < .001). As well, fatigue and sleepiness were positively correlated (r = .36, p = .04).

CONCLUSIONS

RLS is a significant sleep disorder that may have an impact on diabetes management and health outcomes. More research should be conducted on the impact of RLS in sleep to improve diabetic management.

Effects of food on the single-dose pharmacokinetics/pharmacodynamics of tizanidine capsules and tablets in healthy volunteers

BACKGROUND

A multiparticulate capsule formulation of the alpha2-adrenergic agonist tizanidine has been developed to decrease C(max), AUC, and associated somnolence, while maintaining efficacy.

OBJECTIVE

The purpose of this study was to compare the pharmacokinetics and impact of somnolence on cognitive function after single doses of the tablet and capsule formulations of tizanidine under fed and fasted conditions in healthy volunteers.

METHODS

This Phase I, single-dose, randomized, open-label, 4-way crossover study was conducted at MDS Pharma Services, Belfast, United Kingdom. Healthy male and female adult subjects received tizanidine (8 mg) as tablets and capsules under fasting and nonfasting conditions. Blood samples were collected to determine plasma tizanidine pharmacokinetic profiles, and computerized cognitive function tests were performed that yielded a validated composite score, Power of Attention, an index of sedation.

RESULTS

Ninety-six patients were enrolled in the study (54 men, 42 women; mean [SD] age, 27 [8] years [range, 18-52 years]; mean [SD] body weight, 71.7 [12.4] kg [range, 46-102 kg]). Tizanidine tablets and capsules were found to be bioequivalent after fasting. In the fed state, mean C(max) and AUC(0-t) were substantially decreased, by 33.8% and 15.4%, comparing the capsules and tablets, respectively. The median T(max) increased significantly from 1.41 to 3.0 hours (P < 0.001). Administration of the capsules with food resulted in <20% difference in mean C(max) and AUC(0-t) compared with the fasting state, whereas mean C(max) and AUC(0-t) were 22.6% and 45.2% higher when the tablet formulation was administered with food. The onset of impairment in Power of Attention was significantly delayed from 0.75 to 1.5 hours postdose when capsules were administered with food compared with the other conditions (P < 0.001). The most commonly reported adverse events were asthenia, somnolence, and orthostatic hypotension. A significantly lower adverse event rate was observed in the combined capsules group compared with the tablets, suggesting that differences in tolerability may exist.

CONCLUSIONS

The results of this study in healthy volunteers suggest that the capsule and tablet formulations of tizanidine were bioequivalent only in the fasted state. The capsule formulation exhibited a food effect that reduced C(max) and AUC(0-t), and significantly increased T(max), which was associated with a delay in cognitive impairment. The large interpatient variability in plasma profiles most likely dampened the ability to fully elucidate the differences between the 2 formulations.

Associations between sleep and cortisol responses to stress in children and adolescents: a pilot study

A growing body of animal and human research suggests reciprocal associations between sleep and activity of the hypothalamic pituitary adrenocortical (HPA) axis. However, few studies have examined associations between sleep and stress-induced cortisol responses in children and adolescents. This pilot study examined associations among 3 sleep parameters (sleep-wake behavior problems, daytime sleepiness, sleep quantity) and cortisol responses to stress in 31 participants ages 10 to 17 (15 males, 16 females). During a "rest" session in which participants habituated to the laboratory, daytime sleepiness, sleep-wake behavior problems, and sleep quantity were assessed using a modified Sleep Habits Survey. On a separate day, participants completed a laboratory stress session involving 3 performance stressors. Salivary cortisol was collected during baseline, stress, and recovery periods. Significant associations between participant reported sleep-wake behavior problems and cortisol reactivity were found, with greater sleep-wake behavior problems associated with decreased cortisol responses. No associations emerged between sleep quantity and cortisol responses to stress; daytime sleepiness showed a trend toward an effect on cortisol reactivity. Although preliminary, results suggest there may be important influences of sleep quality but not quantity on HPA regulation and responses to daytime stressors in children and adolescents, and further study is warranted.

Case study: psychiatric misdiagnosis of non-24-hours sleep-wake schedule disorder resolved by melatonin

This case study describes a 14-year-old male suffering from significant academic and personal difficulties, who has been diagnosed with depression, schizotypal personality disorder, and learning disabilities. Because of excessive sleepiness, assessment for a potential sleep disorder was performed. An overnight polysomnographic study revealed no primary sleep disorders. Wrist actigraphy revealed a non-24-hour sleep-wake pattern. Delay in temperature rhythm and dissociation with melatonin rhythms were also noted. Treatment with oral melatonin restored normal sleep-wake schedule. In a follow-up psychiatric evaluation, none of the above diagnoses were present. Greater awareness of sleep disorders may prevent psychiatric misdiagnosis of treatable sleep-wake schedule disorders.

Prostaglandin D Synthase (β-trace) in Healthy Human Sleep

STUDY OBJECTIVES

The prostaglandin D system plays an important role in animal sleep. In humans, alterations in the prostaglandin D system have been found in diseases exhibiting sleep disturbances as a prominent symptom, such as trypanosoma infection, systemic mastocytosis, bacterial meningitis, major depression, or obstructive sleep apnea. Assessment of this system's activity in relation to human physiologic sleep was the target of the present study.

DESIGN

Serum concentrations of lipocalin-type prostaglandin D synthase (L-PGDS, former beta-trace), and plasma levels of the pineal hormone melatonin were measured in 20 healthy humans (10 women, 10 men; aged: 23.3 +/- 2.39 years) at 4-hour intervals over a period of 5 days and nights, which included physiologic sleep, rapid eye movement sleep deprivation, and total sleep deprivation. In addition, the serum L-PGDS and plasma melatonin levels of 6 subjects were determined under conditions of bright white (10,000 lux) or dark red light (< 50 lux) in a crossover design during total sleep deprivation. Nocturnal blood sampling was performed by a through-the-wall tube system. L-PGDS was measured by an automated immunonephelometric assay, and melatonin was analyzed by direct radioimmunoassay.

RESULTS

Serum L-PGDS concentrations showed marked time-dependent changes with evening increases and the highest values at night (P < .0005). This nocturnal increase was suppressed during total sleep deprivation (P < .05), independent of external light conditions and melatonin secretion. Rapid eye movement sleep deprivation had no impact on circulating L-PGDS levels.

CONCLUSIONS

The circadian L-PGDS pattern and its suppression by total sleep deprivation indicate an interaction of the prostaglandin D system and human sleep regulation. L-PGDS measurements may well provide new insights into physiologic and pathologic sleep regulation in humans.

Plasma C-reactive protein levels among children with sleep-disordered breathing

INTRODUCTION

Levels of C-reactive protein (CRP), an important serum marker of inflammation with major implications for cardiovascular morbidity and atherogenesis, are elevated among adult patients with sleep-disordered breathing (SDB). We hypothesized that elevated CRP plasma levels would also be present among children with SDB.

METHODS

Eighty-one children (mean age: 9.3 +/- 3.7 years) underwent polysomnographic evaluations. Samples for plasma CRP level and lipid profile determinations were drawn the next morning.

RESULTS

Because plasma CRP levels were not normally distributed in this cohort, logarithmic transformation was applied. Log plasma CRP levels were significantly higher in the SDB group (obstructive apnea/hypopnea index [AHI] of > or =5), compared with the mild SDB group (AHI of > or =1 and <5) and the control group (AHI of <1). Significant positive correlations were found between log CRP levels and AHI (r =.53) and arousal index (r =.28), whereas an inverse correlation was found between the lowest nocturnal arterial oxygen saturation and log CRP levels (r = -.47). These correlations persisted after exclusion of outliers. Moreover, 94% of the children with elevated log CRP levels reported excessive daytime sleepiness and/or learning problems, compared with 62% of the children with normal log CRP levels.

CONCLUSIONS

Plasma CRP levels were increased among some children with SDB and were correlated with AHI, arterial oxygen saturation nadir, and arousal index measures. These changes were particularly prominent among children who were sleepy or presented with neurobehavioral complaints. The intermittent hypoxemia and sleep fragmentation of SDB may underlie inflammatory responses, the magnitude of which may ultimately lead to the cardiovascular, cognitive, and behavioral morbidities of SDB.

L-DOPA-induced excessive daytime sleepiness in PD: a placebo-controlled case with MSLT assessment

A 74-year-old patient with idiopathic Parkinson's disease was evaluated for unintended sleep episodes that occurred after long-term treatment with 400 mg/day of L-dopa. Overnight sleep studies and multiple sleep latency testing were carried out under double-blind administration of either L-dopa or placebo. Mean sleep latency with L-dopa was 7 minutes, in contrast to a normal value of 19 minutes, 25 seconds with placebo. The authors' results suggest that L-dopa may cause daytime somnolence in some patients with Parkinson's disease.

Autoantibodies to a 68/48 kDa protein in chronic fatigue syndrome and primary fibromyalgia: a possible marker for hypersomnia and cognitive disorders

OBJECTIVE

To identify antinuclear antibodies (ANA) specific for chronic fatigue syndrome (CFS), and in related conditions such as fibromyalgia (FM) or psychiatric disorders.

METHODS

One hundred and fourteen CFS patients and 125 primary and secondary FM patients were selected based on criteria advocated by the Centers for Disease Control and Prevention and by the American College of Rheumatology, respectively. As controls, healthy subjects and patients with either various psychiatric disorders or diffuse connective tissue diseases were included. Autoantibodies were examined by immunoblot utilizing HeLa cell extracts as the antigen.

RESULTS

Autoantibodies to a 68/48 kDa protein were present in 13.2 and 15.6% of patients with CFS and primary FM, respectively. In addition, autoantibodies to a 45 kDa protein were found in 37.1 and 21.6% of the patients with secondary FM and psychiatric disorders, respectively. Meanwhile, these two autoantibodies were not found at all in connective tissue disease patients without FM, nor in healthy subjects (P<0.05). As a group, the anti-68/48 kDa-positive CFS patients presented more frequently with hypersomnia (P<0.005), short-term amnesia (P<0.07) or difficulty in concentration (P<0.05) than those CFS patients without the antibodies.

CONCLUSIONS

The presence of the anti-68/48 kDa protein antibodies in a portion of both CFS and primary FM patients suggests the existence of a common immunological background. These antibodies may find utility as possible markers for a clinicoserological subset of CFS/FM patients with hypersomnia and cognitive complaints.

REM sleep and mood state in childbearing women: sleepy or weepy?

STUDY OBJECTIVES

To test the hypotheses that: 1) an increase in endogenous progesterone levels during the luteal phase of the menstrual cycle will alter REM sleep and mood state, and 2) a decrease in endogenous progesterone levels during postpartum will also alter REM sleep and mood state.

DESIGN

A longitudinal descriptive study utilizing ambulatory polysomnography for two consecutive nights at seven time points.

SETTING

Subject's homes.

PARTICIPANTS

The first hypothesis was tested with 34 women studied during both the follicular and luteal phases of their menstrual cycle. The second hypothesis was tested with 31 women who completed the sleep studies during pregnancy and at one month postpartum.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Women who ovulated (high levels of serum progesterone in the luteal phase) had shorter REM latency, more REM sleep, and more positive mood state compared to those who did not ovulate (low luteal progesterone). Compared to the third trimester (high progesterone), REM latency was significantly shorter at one month postpartum (low progesterone). Mood state was most positive at the second trimester and most negative at one month postpartum.

CONCLUSIONS

REM sleep and mood state were related to low progesterone levels during the menstrual cycle, but postpartum REM sleep and mood state were related to increased wake time rather than changes in progesterone levels.

Elevation of plasma cytokines in disorders of excessive daytime sleepiness: role of sleep disturbance and obesity

Excessive daytime sleepiness (EDS) and fatigue are frequent symptoms in the general population and the chief complaint of the majority of patients at Sleep Disorders Centers. There is evidence that the inflammatory cytokines tumor necrosis factor-alpha (TNF alpha), interleukin-1beta (IL-1beta), and IL-6 are involved in physiological sleep regulation and that their administration to humans is associated with sleepiness and fatigue. To explore whether plasma levels of TNF alpha, IL-1beta, and IL-6 are elevated in patients with EDS, we measured morning plasma levels of TNF alpha, IL-1beta, and IL-6 in 12 sleep apneics, 11 narcoleptics, 8 idiopathic hypersomniacs, and 10 normal controls. TNF alpha was significantly elevated in sleep apneics and narcoleptics compared to that in normal controls (P < 0.001 and P = 0.001, respectively). Plasma IL-1beta concentrations were not different between sleep disorder patients and controls, whereas IL-6 was markedly and significantly elevated in sleep apneics compared to that in normal controls (P = 0.028). The primary factor influencing TNF alpha values was the degree of nocturnal sleep disturbance, whereas the primary determinant for IL-6 levels was the body mass index. Our findings suggest that TNF alpha and IL-6 might play a significant role in mediating sleepiness and fatigue in disorders of EDS in humans.

Disturbed hypothalamic-pituitary axis in idiopathic recurring hypersomnia syndrome

Disturbed function of the hypothalamic-pituitary axis at adrenal and thyroid levels was found during an episode of hypersomnia in the idiopathic recurring hypersomnia syndrome. These endocrinological abnormalities, abolished ACTH and cortisol responses to insulin-induced hypoglycemia and absent TSH response to TRH, normalised thereafter in the symptom-free interval. These data support the hypothesis that Kleine-Levin syndrome is related to an intermittent hypothalamic dysfunction.

Hypersomnolent and nonhypersomnolent patients with upper airway obstruction during sleep

When the syndrome consisting of sleep-induced apnea and hypersomnolence is due to upper airway obstruction, the hypersomnolence is believed to be the direct result of deprivation of sleep related to such obstructions. The purpose of this report is to describe a group of four asymptomatic subjects with upper airway obstruction during sleep. These subjects were matched with a group of patients with the syndrome of sleep-induced apnea and hypersomnolence. There were no significant differences between symptomatic and asymptomatic groups in terms of the absolute number of upper airway obstructions (252 vs 231), their mean duration (20.8 vs 25.9 seconds), the mean arterial carbon dioxide tension during sleep (39 vs 39 mm Hg), or the electroencephalographic patterns during sleep. The only variables that emerged as significantly different between the two groups were the weights (128 vs 90 kg; P less than 0.05), the low arterial oxygen pressure (PaO2) on waking (54 vs 80 mm Hg; P less than 0.002), and the lower PaO2 during sleep (47 vs 70 mm Hg; P less than 0.01) in the symptomatic patients. From these data, we conclude that the hypersomnolence in patients with sleep-induced apnea due to upper airway obstruction cannot be explained by deprivation of sleep, and other factors need to be carefully examined in future studies.

Absence of sleep-related growth hormone elevations in myotonic dystrophy

There is evidence that in myotonic dystrophy, the endocrine and central nervous systems are affected. To study a possible relationship between both defects, we investigated nocturnal sleep patterns and associated growth hormone secretion in two men and three women with myotonic dystrophy. In three patients who were clinically the most severely affected by myotonic dystrophy, plasma growth hormone elevations related to the slow-wave phase of sleep were absent. The two least severely affected patients had plasma growth hormone increases of low magnitude and brief duration (from 0.4 ng per milliliter to 13.0 ng per milliliter). These data suggest a failure of integration at a subcortical level of the slow-wave phase of sleep with the hypothalamic-pituitary mechanisms of growth hormone secretion. Thalamic neuronal lesions occurring in myotonic dystrophy could be responsible for such failure.