Sleep‐Disordered Breathing and the Association With Cardiovascular Risk

Morbidity and mortality of middle-aged and elderly narcoleptics

OBJECTIVES

The objective of the study was to evaluate the morbidities and mortality in a national group of middle-aged and elderly narcolepsy patients before and after the first diagnosis of the condition.

METHODS

From the Danish National Patient Registry (NPR), 1174 patients (45.1% males) aged 20-59 years and 339 patients (44.8% males) aged 60+ who received a diagnosis of narcolepsy between 1998 and 2014 were compared, respectively, with 4716 and 1353 control citizens matched for age, gender and geography, who were randomly chosen from the Danish Civil Registration System Statistics. In the NPR, all morbidities are grouped into major WHO classes.

RESULTS

Middle-aged and elderly patients had more health contacts before and after their narcolepsy diagnosis with respect to several disease domains: infections, neoplasm, endocrine/metabolic diseases/diabetes, mental/psychiatric, neurological (including epilepsy), eye, cardiovascular (hypertension, ischemic heart disease), respiratory (upper-airway infections, sleep apnea), gastrointestinal, musculoskeletal (including discopathies) and skin diseases. Narcolepsy patients had lower reproductive rates. Furthermore, patients showed significantly more health contacts due to the evaluation and control contacts for disease and symptoms. Patients suffered from significantly more multiple diseases than did controls. The 17-year hazard ratio mortality rates were 1.35 (95% CI, 0.94-1.95, p = 0.106) among 20-59 year-olds, and 1.38 (1.12-1.69, p = 0.002) among those aged 60+ years.

CONCLUSION

There are higher rates of morbidity in several disease domains before and after a diagnosis of narcolepsy. Elderly narcolepsy patients have higher mortality rates.

Markers of Sleep-Disordered Breathing and Prediabetes in US Adults

Background. Prediabetes is a preclinical stage in the hyperglycemia continuum where subjects are at increased risk of developing diabetes. Several studies reported a positive association between markers of sleep-disordered breathing (SDB) and diabetes. However, few studies investigated the relationship between SDB markers and prediabetes. Methods. We examined 5,685 participants ≥20 years from the National Health and Nutrition Examination Survey (NHANES) 2005-2008. The exposure of interest was SDB markers including sleep duration, snoring, snorting, and daytime sleepiness. The outcome was prediabetes (n = 2058), among subjects free of diabetes. Results. SDB markers were associated with prediabetes. Compared to those without any sleep disturbance, the multivariable odds ratio (OR) (95% confidence interval (CI)) of prediabetes among those with three or more SDB markers was 1.69 (1.28-2.22). In subgroup analyses, the association between SDB markers and prediabetes was stronger among women (OR (95% CI) = 2.09 (1.36-3.23) when compared to men (1.52 (1.00-2.35)) and was present among non-Hispanic whites (2.66 (1.92-3.69)) and Mexican Americans (1.99 (1.13-3.48)), but not among non-Hispanic blacks (1.10 (0.70-1.73)). Conclusion. SDB markers were associated with prediabetes. This association was stronger in women and was present mainly in non-Hispanic whites and Mexican Americans.

Sleep physiology and sleep disorders in childhood

Sleep has long been considered as a passive phenomenon, but it is now clear that it is a period of intense brain activity involving higher cortical functions. Overall, sleep affects every aspect of a child's development, particularly higher cognitive functions. Sleep concerns are ranked as the fifth leading concern of parents. Close to one third of all children suffer from sleep disorders, the prevalence of which is increased in certain pediatric populations, such as children with special needs, children with psychiatric or medical diagnoses and children with autism or pervasive developmental disorders. The paper reviews sleep physiology and the impact, classification, and management of sleep disorders in the pediatric age group.

Diurnal variability of C-reactive protein in obstructive sleep apnea

OBJECTIVE

The objective of this study is to examine the diurnal variability of C-reactive protein (CRP) in obstructive sleep apnea (OSA).

METHODS AND MEASUREMENTS

Participants included 44 women and men with untreated OSA (mean apnea/hypopnea index = 37.5, SD +/- 28) and 23 healthy adults with no OSA. Sleep was monitored with polysomnography in the University of California San Diego General Clinical Research Center. Over a 24-h period, blood was collected every 2 h, and CRP levels were determined.

RESULTS

Adjusting for age, gender, and body mass index, a significant group by time interaction showed that patients with OSA had higher CRP levels during the daytime (8:00 a.m.-8:00 p.m.) versus the nighttime (10:00 p.m. until 6:00 p.m.; p < 0.001). Non-apneics showed no significant change in CRP levels during the 24 h.

CONCLUSIONS

The findings indicate that sleep apnea patients have disproportionately elevated CRP levels in the day versus the nighttime, possibly as a result of carryover effects of nighttime arousal into the daytime.

Post- to pre-overnight sleep systolic blood pressures are associated with sleep respiratory disturbance, pro-inflammatory state and metabolic situation in patients with sleep-disordered breathing

OBJECTIVE

The aim of the current study was to investigate whether changes in post- to pre-overnight sleep systolic blood pressure (SSBP) are associated with sleep respiratory disturbance, pro-inflammatory state, and metabolic situation in patients with sleep-disordered breathing (SDB).

METHODS

Anthropometry, sleep polysomnography, biochemical markers, and pre- and post-overnight sleep BP were measured from 263 SDB patients. All SDB patients were further subgrouped into MORNING SURGE (% changes from post- to pre-overnight SSBP >+1SD of this cohort), MORNING DROP (% changes <-1SD), CONSTANT HIGH (% changes within+/-1SD, averaged SSBP>130mmHg) and CONSTANT LOW (% changes within+/-1SD, averaged SSBP<130mmHg).

RESULTS

BMI, neck circumference, waistline circumference, respiratory disturbance index, arousal index, lowest oxygen saturation, duration of SaO(2)<90%, blood glucose, hs-CRP, and metabolic syndrome score in MORNING SURGE and CONSTANT HIGH were significantly greater than those in CONSTANT LOW. Except metabolic syndrome score, all other parameters in MORNING DROP were similar to those in CONSTANT LOW.

CONCLUSION

Patients with SDB whose post- to pre-overnight SSBPs were elevated or maintained a constant high have more sleep respiratory disturbance, more pro-inflammatory state, and higher metabolic syndrome indices than the rest. Without subdividing into CONSTANT LOW, MORNING DROP, CONSTANT HIGH, and MORNING SURGE, the important pathophysiologic points of SDB patients will possibly be missed.

Obstructive sleep apnea and insulin resistance: a role for microcirculation?

Obstructive sleep apnea is an increasingly recognized medical problem. The recent attention to its frequency in the general population and its important role in metabolic, vascular, and behavioral aspects have sharply increased the number and nature of investigations, thereby revealing new aspects that open new approaches in research. Whereas obstructive sleep apnea is a well-known phenomenon accompanying obesity and diabetes, new findings strongly suggest that this close relationship may also operate in the opposite direction. Indeed obstructive sleep apnea may be a primary feature inducing or aggravating a series of vascular and metabolic disturbances closely resembling the metabolic syndrome. This review will discuss established and potential mechanisms responsible for these changes. Obstructive sleep apnea indeed appears to gather all the elements necessary to induce insulin resistance, hypertension, and possibly heart failure. After careful analysis of these modifications and considering how they are intertwined, we propose that microcirculation could represent the common denominator mediating the progression of this pathology, as it is eventually the case in the metabolic syndrome and diabetes domain. This plausible hypothesis is discussed in detail and should be verified by appropriate preclinical and clinical protocols, which are now achievable by using noninvasive techniques in humans.