Relationship between type 2 diabetes mellitus and markers of cutaneous melanoma aggressiveness: an observational multicentric study in 443 patients with melanoma.

BACKGROUND: Some studies have suggested a relationship between type 2 diabetes mellitus (T2DM) and increased incidence of melanoma. Efforts are under way to identify preventable and treatable factors associated with greater melanoma aggressiveness, but no studies to date have examined the relationship between T2DM and the aggressiveness of cutaneous melanoma at diagnosis. OBJECTIVES: To explore potential associations between T2DM, glycaemic control and metformin treatment and the aggressiveness of cutaneous melanoma. METHODS: We conducted a cross-sectional multicentric study in 443 patients diagnosed with cutaneous melanoma. At diagnosis, all patients completed a standardized protocol, and a fasting blood sample was extracted to analyse their glucose levels, glycated haemoglobin concentration and markers of systemic inflammation. Melanoma characteristics and aggressiveness factors [Breslow thickness, ulceration, tumour mitotic rate (TMR), sentinel lymph node (SLN) involvement and tumour stage] were also recorded. RESULTS: The mean (SD) age of the patients was 55·98 (15·3) years and 50·6% were male. The median Breslow thickness was 0·85 mm. In total, 48 (10·8%) patients were diagnosed with T2DM and this finding was associated with a Breslow thickness > 2 mm [odds ratio (OR) 2·6, 95% confidence interval (CI) 1·4-4·9; P = 0·004)] and > 4 mm (OR 3·6, 95% CI 1·7-7·9; P = 0·001), TMR > 5 per mm2 (OR 4·5, 95% CI 1·4-13·7; P = 0·009), SLN involvement (OR 2·3, 95% CI 1-5·7; P = 0·038) and tumour stages III-IV (vs. I-II) (OR 3·4, 95% CI 1·6-7·4; P = 0·002), after adjusting for age, sex, obesity, alcohol intake and smoking habits. No significant associations emerged between glycated haemoglobin levels, metformin treatment and melanoma aggressiveness. CONCLUSIONS: T2DM, rather than glycaemic control and metformin treatment, is associated with increased cutaneous melanoma aggressiveness at diagnosis.

Association between sleep apnea and low bone mass in adults: a systematic review and meta-analysis.

We performed a systematic review of the literature to assess the association between sleep apnea and bone metabolism diseases including osteoporosis in adult population. Results from clinical trials suggest that the association between sleep apnea and low bone mass in adults is possible. INTRODUCTION: This study aimed to synthesize existing evidence on the potential association between sleep apnea and low bone mass in adults. METHODS: Electronic searches of five databases were performed. The inclusion criteria consisted of studies in humans that assessed potential associations between sleep apnea and bone metabolic diseases in an adult population. For diagnosis of sleep apnea overnight polysomnography, home polygraphy, or validated records from healthcare databases were considered. Reduced bone density, osteoporosis, serum/urinary levels for markers of bone formation and resorption, or risk of fractures caused without history of trauma were considered indicators of low bone mass. A random-effects model meta-analysis was applied when possible. RESULTS: Of the 963 relevant references, 12 studies met our inclusion criteria and were assessed to be of medium to low bias. Nine out of 12 studies reported an association between sleep apnea and low bone mass (increased bone resorption markers, reduced bone density, and higher risk of osteoporosis). Two studies did not report a significant association, whereas one study reported an increase of bone density in sleep apnea patients compared to non-sleep apnea patients. Meta-analysis of 2 studies (n = 112,258 patients) showed that sleep apnea was a significant risk factor for osteoporosis (odds ratio (OR), 1.92; 95%CI, 1.24 to 2.97; I2 = 66%); females only had an OR of 2.56 (95% CI, 1.96 to 3.34; I2 = 0%) while the OR in males was 2.03 (95% CI, 1.24 to 3.35; I2 = 38%). CONCLUSIONS: An association between sleep apnea and low bone mass in adults is plausible, but supporting evidence has a risk of bias and is inconsistent.

Treatment with TUG891, a free fatty acid receptor 4 agonist, restores adipose tissue metabolic dysfunction following chronic sleep fragmentation in mice.

BACKGROUND: Sleep fragmentation (SF), a frequent occurrence in multiple sleep and other diseases leads to increased food intake and insulin resistance via increased macrophage activation and inflammation in visceral white adipose tissue (VWAT). Free fatty acid receptor 4 (FFA4) is reduced in pediatric sleep apnea patients and FFA4 agonists have been proposed in the treatment of obesity and metabolic dysfunction. METHODS: Male mice were subjected to SF exposures for 6 weeks, and treated during the last 2 weeks with either TUG891, a potent and selective FFA4 agonist, or vehicle (Veh). Glucose and insulin tolerance tests and VWAT insulin sensitivity tests were conducted (phosphorylated Akt/total Akt), along with flow cytometric assessments of VWAT macrophage polarity, and T-cell lymphocyte subsets. RESULTS: SF-TUG891 mice showed reduction in food consumption, weight gain and VWAT mass. Furthermore, TUG891 treatment ameliorated glucose tolerance test and insulin tolerance test responses and increased VWAT p-Akt/Akt responses to insulin. Increases in M1/M2 macrophages and decreased Treg counts in VWAT associated with SF were markedly improved by TUG891, and VWAT macrophages from TUG891-treated mice had markedly attenuated insulin resistance effects on naïve cultured adipocytes. CONCLUSIONS: Treatment with an FFA4 agonist reverses SF-induced food intake increases and gains in body weight, and significantly attenuates VWAT inflammation and insulin resistance. Thus, interventional dietary or pharmaceutical strategies aimed at increasing FFA4 activity may serve as potentially useful adjunctive therapies for sleep disorders accompanied by metabolic morbidity.

Metabolic consequences of snoring in adolescents and younger adults: a population study in Chile.

STUDY OBJECTIVES: To investigate the potential association between snoring and other symptoms indicative of sleep-disordered breathing and metabolic syndrome (MetS) in Hispanic adolescents and younger adults using a large population-based survey. METHODS: Sleep-related information, anthropometric measurements and fasting blood samples markers of MetS were obtained from subjects aged 15-40 years collected through the 2nd Chilean Health Survey. Regression models were constructed to evaluate the associations of snoring with MetS, hypertension and serum cholesterol levels. The modulating effect of sleep duration was accounted for in the models. RESULTS: A total of 2147 subjects (42% males, mean age 27.9±7.6 years) were included. Snoring and short sleep duration were present in 43.5 and 25% of the entire population, respectively. MetS was detected in 19.5% of the subjects. In the adjusted regression model, the odds of MetS among snoring subjects were 2.13 times higher (95% confidence interval (CI): 1.52-2.99; P<0.01), and 1.53-fold higher odds of elevated cholesterol also emerged (95% CI: 1.12-2.10; P<0.01). However, the odds of hypertension were not increased by the presence of snoring after adjusting for confounders. In addition, snoring was associated with an increase of 7.26 and 6.56 mg dl-1 for total and low-density lipoprotein cholesterol, respectively, even after adjusting for age, sex and body mass index. Short sleep duration was associated with a small albeit significant risk increase for high systolic blood pressure. CONCLUSIONS: In this large population-based sample of young Hispanic adults and adolescents, snoring, but not sleep duration, emerged as an independent risk factor for dyslipidemia and MetS, but not for hypertension.

Epigenomic profiling in visceral white adipose tissue of offspring of mice exposed to late gestational sleep fragmentation.

BACKGROUND: Sleep fragmentation during late gestation (LG-SF) is one of the major perturbations associated with sleep apnea and other sleep disorders during pregnancy. We have previously shown that LG-SF induces metabolic dysfunction in offspring mice during adulthood. OBJECTIVES: To investigate the effects of late LG-SF on metabolic homeostasis in offspring and to determine the effects of LG-SF on the epigenome of visceral white adipose tissue (VWAT) in the offspring. METHODS: Time-pregnant mice were exposed to LG-SF or sleep control during LG (LG-SC) conditions during the last 6 days of gestation. At 24 weeks of age, lipid profiles and metabolic parameters were assessed in the offspring. We performed large-scale DNA methylation analyses using methylated DNA immunoprecipitation (MeDIP) coupled with microarrays (MeDIP-chip) in VWAT of 24-week-old LG-SF and LG-SC offspring (n=8 mice per group). Univariate multiple-testing adjusted statistical analyses were applied to identify differentially methylated regions (DMRs) between the groups. DMRs were mapped to their corresponding genes, and tested for potential overlaps with biological pathways and gene networks. RESULTS: We detected significant increases in body weight (31.7 vs 28.8 g; P=0.001), visceral (642.1 vs 497.0 mg; P=0.002) and subcutaneous (293.1 vs 250.1 mg; P=0.001) fat mass, plasma cholesterol (110.6 vs 87.6 mg dl(-1); P=0.001), triglycerides (87.3 vs 84.1 mg dl(-1); P=0.003) and homeostatic model assessment-insulin resistance values (8.1 vs 6.1; P=0.007) in the LG-SF group. MeDIP analyses revealed that 2148 DMRs (LG-SF vs LG-SC; P<0.0001, model-based analysis of tilling-arrays algorithm). A large proportion of the DMR-associated genes have reported functions that are altered in obesity and metabolic syndrome, such as Cartpt, Akt2, Apoe, Insr1 and so on. Overrepresented pathways and gene networks were related to metabolic regulation and inflammatory response. CONCLUSIONS: Our findings show a major role for epigenomic regulation of pathways associated with the metabolic processes and inflammatory responses in VWAT. LG-SF-induced epigenetic alterations may underlie increases in the susceptibility to obesity and metabolic syndrome in the offspring.

Effect of resveratrol on visceral white adipose tissue inflammation and insulin sensitivity in a mouse model of sleep apnea.

BACKGROUND: Sleep fragmentation (SF) increases food intake and the risk of obesity, and recruits macrophages to visceral white adipose tissue (VWAT) promoting tissue inflammation and insulin resistance. Administration of resveratrol (Resv) has been associated with significant improvements in high-fat diet-induced obesity, inflammation and insulin resistance. METHODS: Male mice were subjected to SF or sleep control conditions for 8 weeks, and treated with either Resv or vehicle (Veh). Fasting plasma levels of glucose, insulin and leptin were obtained and VWAT insulin sensitivity tests were performed (phosphorylated AKT/total AKT), along with flow-cytometric assessments for VWAT macrophages (M1 and M2) and T-cell lymphocytes (CD4+, CD8+ and T regulatory cell (Treg)). RESULTS: SF-Veh and SF-Resv mice showed increased food consumption and weight gain. However, although SF-Veh mice exhibited increased fasting insulin and leptin levels, and reduced VWAT p-AKT/AKT responses to insulin, such alterations were abrogated in SF-Resv-treated mice. Increases in M1, reduced M2 counts and increased tumor necrosis factor-α release emerged in SF-Veh macrophages compared with all other three groups. Similarly, increased CD8+ and reduced Treg lymphocyte counts were apparent in SF-Veh. CONCLUSIONS: Resveratrol does not reverse the SF-induced increases in food intake and weight gain, but markedly attenuates VWAT inflammation and insulin resistance, thereby providing a potentially useful adjunctive therapy in the context of sleep disorders manifesting metabolic morbidity.

Effects of adenotonsillectomy on plasma inflammatory biomarkers in obese children with obstructive sleep apnea: A community-based study.

BACKGROUND: Obesity and obstructive sleep apnea syndrome (OSA) are highly prevalent and frequently overlapping conditions in children that lead to systemic inflammation, the latter being implicated in the various end-organ morbidities associated with these conditions. AIM: To examine the effects of adenotonsillectomy (T&A) on plasma levels of inflammatory markers in obese children with polysomnographically diagnosed OSA who were prospectively recruited from the community. METHODS: Obese children prospectively diagnosed with OSA, underwent T&A and a second overnight polysomnogram (PSG) after surgery. Plasma fasting morning samples obtained after each of the two PSGs were assayed for multiple inflammatory and metabolic markers including interleukin (IL)-6, IL-18, plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), adiponectin, apelin C, leptin and osteocrin. RESULTS: Out of 122 potential candidates, 100 obese children with OSA completed the study with only one-third exhibiting normalization of their PSG after T&A (that is, apnea-hypopnea index (AHI) ≤1/hour total sleep time). However, overall significant decreases in MCP-1, PAI-1, MMP-9, IL-18 and IL-6, and increases in adropin and osteocrin plasma concentrations occurred after T&A. Several of the T&A-responsive biomarkers exhibited excellent sensitivity and moderate specificity to predict residual OSA (that is, AHI⩾5/hTST). CONCLUSIONS: A defined subset of systemic inflammatory and metabolic biomarkers is reversibly altered in the context of OSA among community-based obese children, further reinforcing the concept on the interactive pro-inflammatory effects of sleep disorders such as OSA and obesity contributing to downstream end-organ morbidities.

Sleep fragmentation promotes NADPH oxidase 2-mediated adipose tissue inflammation leading to insulin resistance in mice.

BACKGROUND: Short sleep has been implicated in higher risk of obesity in humans, and is associated with insulin resistance. However, the effects of fragmented sleep (SF) rather than curtailed sleep on glucose homeostasis are unknown. METHODS: Wild-type and NADPH oxidase 2 (Nox2) null male mice were subjected to SF or sleep control conditions for 3 days to 3 weeks. Systemic and visceral adipose tissue (VAT) insulin sensitivity tests, glucose tolerance test, fluorescence-activated cell sorting and immunohistochemistry for macrophages and its sub-types (M1 and M2), and Nox expression and activity were examined. RESULTS: Here we show that SF in the absence of sleep curtailment induces time-dependent insulin resistance, in vivo and also in vitro in VAT. Oxidative stress pathways were upregulated by SF in VAT, and were accompanied by M1 macrophage polarization. SF-induced oxidative stress, inflammation and insulin resistance in VAT were completely abrogated in genetically altered mice lacking Nox2 activity. CONCLUSIONS: These studies imply that SF, a frequent occurrence in many disorders and more specifically in sleep apnea, is a potent inducer of insulin resistance via activation of oxidative stress and inflammatory pathways, thereby opening the way for therapeutic strategies.

Effects of late gestational high-fat diet on body weight, metabolic regulation and adipokine expression in offspring.

AIMS/HYPOTHESIS: Gestational exposures such as dietary changes can alter offspring phenotype through epigenetic modifications and promote increased risk for specific diseases, such as metabolic syndrome. We hypothesized that high-fat diet (HFD) during late gestation would lead increased risk for insulin resistance and hyperlipidemia via associated epigenetic alterations in tissue adipocytokine genes. METHODS: Offspring mice of mothers fed a HFD during late gestation (HFDO) were weighed and their food intake measured weekly till age 20 weeks at which time glucose and insulin tolerance tests, plasma lipid and adipocytokine levels were assessed, as well as mRNA expression in visceral fat. Adipocytokine gene methylation levels in visceral fat, liver and muscle were also assayed. RESULTS: HFDO mice had increased weight accrual and food intake, and exhibited insulin resistance, hyperlipidemia and hyperleptinemia, as well as hypoadiponectinemia. Furthermore, increased methylation of adiponectin and leptin receptor, and decreased methylation of leptin genes with unchanged glucagon-like peptide-1 methylation patterns emerged in HFDO mice. CONCLUSIONS: Taken together, late gestational HFD induces increased risk of metabolic syndrome in the progeny, which is coupled with hypoadiponectinemia as well as with leptin resistance, and concomitant presence of selective tissue-based epigenetic changes among adipocytokine genes.

Sex-dependent GOAL screening performance in adults at risk for obstructive sleep apnea.

OBJECTIVE: To evaluate possible sex-related differences in the performance of the GOAL, a 4-item obstructive sleep apnea (OSA) screening instrument in adults. METHODS: Between July 2019 and June 2021, this cross-sectional study included consecutively recruited patients from one Brazilian sleep laboratory undergoing overnight polysomnography. Individuals with GOAL scores ≥ 2 of a maximum of 4 points are classified at high risk for OSA diagnosis. Actual OSA severity was based on the apnea-hypopnea index: ≥ 5.0/h as any OSA, ≥ 15.0/h as moderate-to-severe OSA, and ≥ 30.0/h as severe OSA. Performance of the GOAL instrument in women and men was assessed by the discriminatory ability (obtained from area under the curve [AUC]-Receiver Operating Characteristic curves) and 2×2 contingency tables. RESULTS: A total of 2,978 subjects (55.3% males) were evaluated. The frequency of GOAL-defined OSA high-risk was statistically higher in men when compared to women (p < 0.001). The GOAL predictive parameters for screening all severity OSA levels were as follows: in females, sensitivity ranging from 58.2% to 78.3% and specificity ranging from 60.0% to 77.6%, while in males, sensitivity ranging from 90.5% to 96.9% and specificity from 20.7% to 46.8%. The GOAL questionnaire had similar discriminatory properties, assessed by AUC, in women and in men: i) any OSA: 0.741 vs. 0.771 (p = 0.204), ii) moderate-to-severe OSA: 0.727 vs. 0.737 (p = 0.595), and iii) severe OSA: 0.728 vs. 0.703 (p = 0.240); respectively. CONCLUSIONS: The GOAL instrument emerges as a useful tool for screening adult individuals and displays similar performance in both women and men.

Effect of continuous positive airway pressure in very elderly with moderate-to-severe obstructive sleep apnea pooled results from two multicenter randomized controlled trials.

STUDY OBJECTIVE: There is very limited information about the effect of continuous positive airway pressure (CPAP) in the very elderly. Here we aimed to analysed the effect of CPAP on a clinical cohort of patients with obstructive sleep apnea (OSA) ≥80 years old. METHODS: Post-hoc pooled analysis of two open-label, multicenter clinical trials aimed to determine the effect of CPAP in a consecutive clinical cohort of elderly (≥70 years old) with moderate-to-severe OSA (apnea-hipopnea index ≥15 events/hour) randomized to receive CPAP or no CPAP for three months. Those consecutive patients ≥80 years old were included in the study. The primary endpoint was the change in Epworth Sleepiness scale (ESS). Secondary outcomes included sleep-related symptoms, quality of life, neurocognitive and mood status as well as office blood pressure measurements. RESULTS: From the initial 369 randomized individuals with ≥70 years, 97 (26.3%) with ≥80 years old were included (47 in the CPAP group and 50 in the no-CPAP group). The mean (SD) age was 81.5 (2.4) years. Average use of CPAP was 4.3 (2.6) hours/night (53% with good adherence) Patients in the CPAP group significantly improved snoring and witnessed apneas as well as AHI (from 41.9 to 4.9 events/hour). However no clinical improvements were seen in ESS (-1.2 points, 95%CI, 0.2 to -2.6), any domain of QSQ, any neurocognitive test, OSA-related symptoms, depression/anxiety or blood pressure levels. CONCLUSIONS: The present study does not support the use of CPAP in very elderly patients with moderate-to-severe OSA.

Myeloid-related protein 8/14 levels in children with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is common in children and leads to multiple end-organ morbidities. Myeloid-related protein (MRP) 8/14 plays an important pathophysiological role in atherosclerosis, and plasma levels correlate with endothelial cell dysfunction. We hypothesised that MRP8/14 levels would be altered in children with OSA. 255 children (aged 7.6+/-1.5 yrs) were included after a sleep study and a morning blood sample. MRP8/14 and interleukin-6 plasma levels were assayed using ELISA and C-reactive protein by immunoturbidometry. Endothelial function was assessed as the hyperaemic response after occlusion of the brachial artery. Plasma log MRP8/14 levels showed apnoea/hypopnoea index (AHI) dose-dependent increases regardless of obesity. Moreover, log MRP8/14 levels correlated with log AHI (r = 0.340, p<0.001) after controlling for age and body mass index Z-score, and with endothelial function. Children with the highest MRP levels (>1.34 ug x mL(-1)) had 2.4- and 5.4-fold increased odds of mild OSA and moderate-to-severe OSA, respectively, after adjusting for confounding variables. Plasma MRP8/14 levels are associated with paediatric OSA and may reflect increased risk for cardiovascular morbidity. The short- and long-term consequences of elevated MRP8/14 on cardiovascular function in the context of paediatric OSA remain to be defined.

Obstructive sleep apnoea is associated with impaired pictorial memory task acquisition and retention in children.

The aim of our study was to evaluate whether obstructive sleep apnoea (OSA) is associated with impaired acquisition and recall of a pictorial-based memory tasks in children. 54 children with OSA and 17 controls matched for age, sex and ethnicity underwent a sleep study (overnight polysomnogram). Before the sleep study subjects completed a 15-min pictorial memory task acquisition consisting of four trials, followed by a free-recall period to assess retention after 10 min and the following morning upon awakening. Children with OSA had a higher obstructive apnoea/hypopnoea index (6.3+/-1.5 events.h(-1) TST) than controls (0.6+/-0.1 events.h(-1) TST) (p<0.0001). Mean learning scores in controls over the four consecutive trials were incrementally better than in children with OSA for the four-trial set (p<0.0001). Both immediate (p<0.0001) and overnight recall performances were worse among OSA children (p<0.0001), who also exhibited declines in recall performance that was absent in controls (p<0.001). Differences in pictorial task acquisition trajectories suggest that children with OSA require more time and an increased number of learning opportunities to reach immediate and long-term recall performances that are reduced compared with controls. Thus, both acquisition and retention of newly learned material are compromised. These findings confirm and expand on the presence of known cognitive deficits in children with OSA.

Corticosteroids suppress in vitro tonsillar proliferation in children with obstructive sleep apnoea.

Intranasal corticosteroids (CS) are potentially useful interventions for children with obstructive sleep apnoea (OSA), and may reduce lymphadenoid tissue size in the upper airway. The present authors hypothesised that CS would reduce cellular proliferation and the production of pro-inflammatory cytokines in a tonsil/adenoid mixed-cell culture system. Dissociated tonsils or adenoids harvested intra-operatively from children with polysomnographically diagnosed OSA were cultured in control medium (CO) or after stimulation with lipopolysaccharide and concanavalin A (STIM), and incubated with dexamethasone (DEX; 10(-5)-10(-7) M), fluticasone (FLU; 10(-5)-10(-14) M) and budesonide (BUD; 10(-4)-10(-14) M). Proliferation and apoptosis were assessed, and supernatants were assayed for the cytokines tumour necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-8. STIM increased tonsillar and adenoidal proliferation compared with CO (1,976+/-133 versus 404+/-69 counts min(-1); n = 54). DEX, FLU and BUD reduced cellular proliferation rates, and exhibited dose-dependent effects, with the potency being FLU>BUD>DEX (n = 25 per group). Conversely, CS increased cellular apoptosis (n = 20 per group). Furthermore, TNF-alpha, IL-8 and IL-6 concentrations in the supernatant were increased by STIM, and markedly reduced by all CS (n = 48 per group). Whole tissue cell cultures of adenoids and tonsils provide a useful approach for in vitro assessment of therapeutic efficacy of corticosteroids in the management of lymphadenoid hypertrophy that underlies obstructive sleep apnoea in children.

Intermittent hypoxia regulates RNA polymerase II in hippocampus and prefrontal cortex.

Intermittent hypoxia (IH) is a major pathological factor in the development of neural deficits associated with sleep-disordered breathing. Here we demonstrate that IH lasting 2 or 30 days, but not sustained hypoxia (SH) of the same duration, was accompanied by several posttranslational modifications of the large subunit of RNA polymerase II, Rpb1, including hydroxylation of proline 1465, phosphorylation of serine 5 residues within the C-terminal domain, and nondegradative ubiquitylation. These modifications were found to occur in two regions of the brain, hippocampal region CA1 and the prefrontal cortex, but not in neocortex, brainstem and CA3 region of hippocampus. We also found that mice exposed to 14 or 30 days of IH, but not SH, demonstrated cognitive deficits in behavioral assays. Furthermore, by using the pheochromocytoma-derived PC12 cell line, we showed that, under in vitro IH conditions, induction of Rpb1 hydroxylation, phosphorylation, and ubiquitylation required that the von Hippel-Lindau protein be present. We hypothesize that the observed modifications of Rpb1 participate in regulating the expression of genes involved in mediating cognitive deficits evoked by chronic IH.

Sleep and behavioral/emotional problems in children: a population-based study.

BACKGROUND: The potential relationships between sleep-wake behaviors and emotional/disruptive problems in otherwise healthy school-aged children are unclear. METHODS: A parental questionnaire was developed for the epidemiologic survey of children's sleep and wake behavioral patterns. The questions covered a wide range of features including sleep length (school days, weekends), time to fall asleep, night awakenings, bedtime and nighttime sleep-related behaviors, daytime sleepiness, irritability, and tiredness. To assess psychiatric symptomatology, the Rutter Scale B2 was completed by teachers. In addition to the total score, sub-scores of emotional, hyperactivity, and conduct problems were obtained. The representative population sample comprised 779 children (403 girls), with an age range of 6-11 years. RESULTS: Hyperactivity and conduct problems at school in boys were both associated with parental reports of bedtime resistance. Hyperactivity was also associated with longer sleep duration during weekends. Conduct and emotional problems in girls were associated with earlier bedtime during school days. Emotional problems in girls were also associated with longer sleep durations in school days and weekends. CONCLUSION: Bedtime resistance was the only sleep behavior associated with either hyperactivity or conduct problems in children, and longer sleep durations appear to occur more frequently in children with both hyperactive or emotional problems. Information about good sleep hygiene at bedtime may help parents setting sleep limits.

[Neonatal intermittent hypoxia and hypertension].

Obstructive apnea during sleep is accompanied by intermittent hypoxia (IH) leading to hypertension and other cardiovascular disturbances. A comparative evaluation of long-term effects of the neonatal IH on the cardiovascular function was performed in normotensive Sprague-Dawley and spontaneously hypertensive rats (SHR). The newborn rats were placed for 30 days to conditions of IH (8 and 21% O2, alternating every 90 s for 12 h/day). Control groups of rats were constantly kept in normoxia. By 6 months, in the spontaneously hypertensive rats submitted to IH at the period of wakefulness there was a statistically significant increase (as compared with control) of the systolic (correspondingly 185.8 +/- 1.7 and 169.9 +/- 1.4 mm Hg, p < 0.01) and diastolic pressure (correspondingly 96.2 +/- 4.9 and 86.0 +/- 2.6 mm Hg, p < 0.01). During sleep, the systolic and diastolic pressure in these rats was higher than in control animals by 10 mm Hg (p < 0.01) and 12 mm Hg (p < 0.01), its decrease during sleep being absent. SHR submitted to IH had an increase in low- to the high-frequency power ratio of the heart rate variability from 0.9 +/- 0.15 to 1.5 +/- 0.17, which indicates a shift of the sympatho-parasympathetic balance in this group towards predominance of the sympathetic component. In the Sprague-Dawley rats submitted to neonatal hypoxia, the above changes were not pronounced. These peculiarities of the hypertensive rats allow establishing connection of the genetic factor with the sympathetic mechanism providing long-term consequences of the neonatal IH for the cardiovascular control in these rats.

Sleep-Disordered Breathing Is Associated with Reduced Mandibular Cortical Width in Children.

INTRODUCTION: Evidence from the adult population suggests that sleep-disordered breathing (SDB) (i.e., obstructive sleep apnea [OSA]) is negatively associated with bone mineral density. Whether a similar association exists in children with SDB has not been investigated. Using the mandibular cortical width (MCW) as a proxy for skeletal bone density, we investigated if children at risk of SDB or diagnosed with OSA have a reduced mandibular cortical width compared to children without SDB. METHODS: Two retrospective cross-sectional studies were performed. The first study included comparison of MCW between 24 children with polysomnographically (PSG) diagnosed OSA and 72 age- and sex-matched control children. The second study included a cohort of children in which SDB was suggested by the Pediatric Sleep Questionnaire (PSQ) ( n = 101). MCW was measured from panoramic radiographs. RESULTS: Multiple-predictors regression analysis from the first study indicated that in children with a severe form of SDB, as induced by OSA severity, there was a negative association with MCW (ß = -0.290, P = 0.049). Moreover, PSG-diagnosed OSA children had thinner MCW (2.9. ± 0.6mm) compared to healthy children (3.5 ± 0.6 mm; P = 0.002). These findings were further supported by the second study illustrating that PSQ total scores were negatively associated with MCW (ß = -0.391, P < 0.001). CONCLUSIONS: Findings suggest that children at risk for or diagnosed with SDB exhibit reduced mandibular cortical width that purportedly may reflect alterations in bone homeostasis. KNOWLEDGE TRANSFER STATEMENT: We report that sleep-disordered breathing (including its severe form, obstructive sleep apnea) in children is associated with reduced mandibular cortical width. This association might be a direct consequence of reduced bone health to sleep-disordered breathing or a reflection that reduced bone formation underlies the development of sleep-disordered breathing. Our findings suggest that mandibular cortical width can be used as an adjunct diagnostic parameter for the diagnosis of sleep-disordered breathing.