Could non-HDL-cholesterol be a better marker of atherogenic dyslipidemia in obstructive sleep apnea?

Background/objectiveObstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.MethodsWe retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects’ lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.ResultsOut of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57–66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.ConclusionsAtherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.     

Sleep time and sleep-related symptoms across two generations – results of the community-based RHINE and RHINESSA studies

Study objectivesTo analyze the association between sleep-related symptoms and sleep length in parents and their children in relation to other risk factors in both generations.MethodThe participants were parents (n = 5,855, age 54.3 ± 6.5 years, 45.2% men) who participated in the community-based Respiratory Health in Northern Europe (RHINE) study and one random member of their adult offspring (n = 5,855, age 30.2 ± 7.7 years, 41.5% men) who participated in the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) study. Both generations responded to identical questionnaires on sleep symptoms, including difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), early morning awakening (EMA), snoring, nocturnal sweating, nocturnal gastroesophageal reflux (nGER), sleep time and excessive daytime sleepiness (EDS). Insomnia was defined as either, or both, DIS and DMS in combination with EDS.ResultsAll sleep variables except nocturnal sweating were more common in offspring whose parents had reported the same symptom. After adjusting for age, gender, BMI, smoking, physical activity, education, center and parents' total number of children, there were independent associations between sleep symptoms in parents and offspring for DIS (adj. OR, 95% CI: 1.52, 1.20–1.93), DMS (1.34, 1.15–1.56), snoring (1.45, 1.15,1.83), nGER (1.65, 1.15–2.37), insomnia (1.39, 1.13–1.73), short sleep time (<6 h/night) (2.51, 1.72–3.68) and EDS (1.48, 1.26,1.72). There were no independent relationships between symptoms in parents and offspring for EMA, nocturnal sweating or long sleep time (>9 h/night).ConclusionThe familiar aggregation of many sleep disturbances was not explained by investigated lifestyle and environmental factors. This supports a heritable factor in sleep problems.     

碘和甲状腺球蛋白诱导大鼠自身免疫性甲状腺炎的研究

目的　研究碘与自身免疫性甲状腺炎 (EAT)的关系。方法　用碘和甲状腺球蛋白 (TG)诱导SD大鼠建立甲状腺炎模型 ,随机分为 5组 ,每组 10只。正常对照组 (NC组 ) ;少量碘组 (LI组 ) :饮 5 0 0 μg/L碘化钠水 ;大量碘组 (HI组 ) :饮 5 0 0mg/L碘化钠水 ;TG组 :于实验第 15天大鼠接受皮内多点注射完全福氏佐剂乳化的TG各 10 0 μg作为初次免疫 ,2周后以不完全福氏佐剂乳化的TG加强免疫 ,以后每周加强免疫 1次至第 6周末实验结束 ;TG HI组 :TG及HI给药方法同上。至第 6周末实验结束处死所有动物 ,用放免法检测血清TG抗体 (TGAb)及甲状腺过氧化物酶抗体 (TPOAb)效价 ,并于光镜下观察甲状腺组织淋巴细胞浸润程度。结果　TG HI组、HI组及TG组甲状腺滤泡破坏及淋巴细胞浸润均较明显 ,TG HI组及HI组与NC组比较 ,P<0 .0 5 ,TG组与NC组比较有增高趋势 ,但无统计学意义。 3组TGAb、TPOAb均明显高于NC组及LI组 (P<0 .0 1;仅HI组TPOAbP<0 .0 5 )。各组TGAb及TPOAb水平与甲状腺病理分级呈正相关关系 (r =0 .9,P<0 .0 5 )。结论　高碘可诱发SD鼠EAT发生 ,TG与高碘结合诱导SD大鼠EAT的作用更明显     

A nationwide survey of excessive daytime sleepiness in Parkinson's disease in France

To determine the prevalence of excessive daytime sleepiness (EDS) and that of dozing and sudden onset of sleep episodes (SOS) while driving in ambulatory patients with Parkinson's disease (PD) in France, a national sample of private and public neurologists was asked to recruit the first 10 consecutive nondemented PD patients. Each patient completed a questionnaire including the Epworth Sleepiness Scale (ESS) and the likelihood of dozing off and experiencing SOS episodes behind the wheel. Clinical and demographic data were collected. One thousand six hundred and twenty‐five patients with PD were included in the survey. Twenty‐nine percent of the patients suffered from EDS (ESS score ≥10) but only 0.8% declared a high chance of dozing while driving and 0.5% reported totally unpredictable SOS episodes while driving. Risk factors for EDS were male gender, reduced activity of daily living, and a high daily levodopa equivalent dosage. Risk factors for SOS episodes while driving were an ESS score ≥10, male gender, and low Hoehn and Yahr staging. EDS is common in ambulatory patients with PD and is a major risk factor for dozing and for SOS episodes behind the wheel in patients who drive. © 2007 Movement Disorder Society     

Restless legs syndrome in Parkinson's disease: a case-controlled study.

Restless legs syndrome (RLS) is a disorder of motor activity with a circadian pattern, occurring frequently in patients with Parkinson's disease (PD). We sought to estimate the prevalence of RLS in Indian PD patients. One hundred twenty-six consecutive PD patients and 128 healthy age- and sex-matched controls were evaluated using a predesigned questionnaire. RLS was present in 10 of 126 cases of PD (7.9%) and 1 of 128 controls (0.8%, P = 0.01). PD patients with RLS were older than those without RLS (63.70 +/- 7.80 years vs. 57.37 +/- 10.04 years; P = 0.05) and had higher prevalence of depression (40% vs. 10.3%; P = 0.023). No demographic factors or factors related to PD correlated with the presence or severity of RLS. RLS is more common among patients with PD than controls. A greater medical recognition of this disorder is needed in view of available effective treatment.     

Excessive daytime somnolence in Japanese patients with Parkinson''s disease

To investigate the prevalence and severity of excessive daytime somnolence (EDS) in Japanese patients with Parkinson's disease (PD) and to examine the main cause of EDS. Fifty-three Japanese patients with PD (PDs: 32 females and 21 males) and 17 controls (10 females and seven males) were evaluated using the Epworth Sleepiness Scale (ESS). The severity of the disease was evaluated by Unified Parkinson's disease Rating Scale (UPDRS), and information about quality and quantity of medications was collected. The correlations amongst EDS and age, severity of PD, duration of illness and medications were analyzed. The mean ESS score was significantly higher in advanced PDs than in controls, and correlated with the UPDRS score (r(s) = 0.743, P < 0.0001). Age, duration of illness and the dose of levodopa weakly correlated with ESS score. The intake of dopamine agonists did not affect the severity of EDS. The mean ESS score in PDs was lower than that reported in PD in European and American studies. EDS in Japanese patients with PD was milder compared with Caucasian patients, which might be due to the lower doses of the medications used in Japan. The results suggest that EDS in PD is mainly because of neuropathological changes of the disease itself.     

A dose–response study of total sleep time and the ability to maintain wakefulness

The apparent connection between sleep debt, performance decrements and workplace accidents has generated a need for feasible vigilance tests that focus on the quantification of daytime sleepiness in occupational settings. The objective of this study was to evaluate the sensitivity of the Maintenance of Wakefulness Test (MWT) to acute sleep deprivation of various doses. Eight healthy female volunteers, mean age 28.9 years (range 23–36), participated in this laboratory study. After an adaptation night, the subjects were assigned to four counterbalanced, randomly ordered night sleep conditions. These four conditions allowed for a time in bed (TIB) of 0, 2, 4 or 8 h, producing a total sleep time of 0, 113, 218 and 427 min, respectively. The ability to sustain wakefulness was measured after the TIB period at 11.00 and 17.00 hours by the MWT. Analysis of variance with repeated measures was used to study the dependence of MWT sleep latencies on the immediately prior TIB period. Both the latency of stage 1 sleep onset and the appearance of slow eye movements reduced significantly with increased sleep loss. The quantitative relationship between the previous total sleep time and the subsequent MWT sleep latencies followed an exponentially decaying function showing a high sensitivity to acute, severe night sleep loss but low sensitivity to less severe sleep restrictions. It is concluded that the MWT seems to be a sensitive method for the estimation of acute sleep deprivation. The test results appear, however, non-linearly related to the earlier sleep debt.     

Fatigue in multiple sclerosis is not due to sleep apnoea

Fatigue is a frequent and disabling phenomenon among patients with multiple sclerosis (MS). Daytime sleepiness is a typical symptom of the sleep apnoea/hypopnoea syndrome due to nocturnal hypoxia and recurrent arousals causing sleep fragmentation. Since MS plaques are often found in the midbrain, brain stem and upper cervical cord on magnetic resonance imaging (MRI) we hypothesized that fatigue in MS patients might be caused by a central respiratory dysfunction. We investigated 10 patients with definite MS by oligography, two questionnaires assessing fatigue (Fatigue Severity Scale, FSS) and daytime sleepiness (Epworth Sleepiness Scale, ESS), MRI and pulmonary function tests. A total of six patients had either an elevated FSS and/or an elevated ESS. None of the six patients with an elevated FSS and/or ESS has an apnoea index > 5/hour. CT₉₀ was normal in nine patients. We conclude that fatigue and daytime sleepiness in MS cannot be explained by nocturnal apnoeas or oxygen desaturations. The Fatigue Severity Scale should be integrated to the extended Barthel index, which is a new instrument for disability assessment in MS patients.