Jan Hedner

Increased incidence of coronary artery disease in sleep apnoea: a long-term follow-up.

An increased incidence of cardiovascular disease has previously been reported in middle-aged males during a follow-up period of 7 yrs. The aim of the present study was to address the incidence of coronary artery disease (CAD) in a larger sample without any heart disease at baseline. The population comprised 308 snorers (245 males and 63 females) with a mean±sd age of 49.0±9.9 yrs in 1991. Data were collected via the Swedish Hospital Discharge Register, National Cause of Death Registry, clinical charts and questionnaires. Over 7 yrs, CAD was observed in 17 (16.2%) of 105 patients with obstructive sleep apnoea (OSA; overnight (6 h) oxygen desaturations ≥30 events) compared with 11 (5.4%) of 203 snorers without OSA. OSA diagnosis at baseline was associated with an increased risk of development of CAD in a multivariate model. In the OSA group, CAD was confirmed in 16 (24.6%) of 65 incompletely treated patients compared with one (3.9%) of 26 efficiently treated subjects. Efficient treatment of OSA reduced this risk. It is concluded that middle-aged sleep apnoeics are at high risk of developing coronary artery disease if they are not treated efficiently, which should be considered in cardiovascular disease prevention models.

Reduction in sympathetic activity after long-term CPAP treatment in sleep apnoea: cardiovascular implications.

Twelve patients with severe obstructive sleep apnoea were included in an open, long-term, prospective, follow-up study addressing the effects of nasal continuous positive airway pressure (CPAP) on sympathetic activity, cardiac structure and blood pressure. Plasma norepinephrine (P-NE) (daytime at rest), daytime and night-time urinary excretion of NE (U-NE), vanylmandelic acid and metanephrines, together with 24 h noninvasive blood pressure (BP) recording and Doppler-echocardiography, were assessed before and after a mean of 20.5 (range 14-26) months of CPAP. Average self-reported use of CPAP was 89% (range 65-100%) of time spent in bed. Resting daytime P-NE ranged 0.35-0.83 ng.ml-1, which is elevated compared to healthy controls. Only night-time U-NE, mean daytime BP and average 24 h BP were related to severity of OSA. Night-time metanephrine was related to daytime and night-time diastolic, as well as night-time systolic, BP. Left ventricular mass index (LVMI) at baseline was correlated to daytime systolic BP and P-NE. Long-term CPAP treatment reduced biochemical markers of sympathetic activity. P-NE decreased by approximately 50%, and daytime and night-time vanylmandelic acid and metanephrine by 32-54%. In contrast, there were no overall reductions in BP or LVMI. It is concluded that obstructive sleep apnoea is associated with high sympathetic activity both during sleep and waking periods. Urinary metanephrine excretion seemed to reflect blood pressure, but neither daytime nor night-time catecholamine excretion was directly related to disease severity in patients with severe obstructive sleep apnoea.(ABSTRACT TRUNCATED AT 250 WORDS)

Morphine-3-glucuronide may functionally antagonize morphine-6-glucuronide induced antinociception and ventilatory depression in the rat

&NA; The effects of the major morphine metabolites, morphine‐3‐glucuronide and morphine‐6‐glucuronide, on nociception were assessed by the tail‐flick, hot‐plate and writhing tests in the rat. Morphine‐3‐glucuronide (M3G) 1.1 × 10−9 mol (0.5 &mgr;g) or saline was injected intracerebroventricularly (i.c.v.) or intrathecally (i.t.) followed by a second injection of 2.0 × 10−10 mol (0.1 &mgr;g) or 2.0 × 10−11 mol (0.01 &mgr;g) morphine‐6‐glucuronide (M6G) 10 min later. Administration of M3G (i.c.v.) significantly attenuated the antinociceptive effects of M6G in the hot‐plate test. After i.t. administration, the antinociceptive effect of M6G in all three tests was significantly reduced in the M3G pretreated group compared to the group receiving saline. The ventilatory effects of 4.0 × 10−9−10 × 10−8 mol (2–5 &mgr;g) M6G and 1.7−2.2 × 10−8 mol (8–10 &mgr;g) M3G given i.c.v. were studied by a whole‐body plethysmographic technique in halothane anaesthetized rats. Separate groups of rats received M3G followed by M6G injection or vice versa. In animals receiving M3G there was a prevention or attenuation of the M6G induced depression of respiratory frequency, tidal volume and minute ventilation compared to control groups receiving M6G in combination with saline. These results show that M3G may functionally antagonize the central antinociceptive effects as well as the ventilatory depression induced by M6G. Interestingly, M3G was more potent in antagonizing the M6G‐induced analgesia after i.t. administration than that after i.c.v. administration, which may suggest that the spinal cord is more sensitive to the non‐opioid excitatory effects of M3G than supraspinal structures.

Therapy with nCPAP: incomplete elimination of Sleep Related Breathing Disorder

Correct assessment of the overall treatment effectiveness requires knowledge about therapy compliance and efficacy. This study aimed to determine overall long-term apnoea alleviation after continuous positive airway pressure (CPAP) in a complete sleep laboratory cohort. Out of 209 consecutive CPAP candidates (mean age 57+/-12 yrs, body mass index (BMI) 30.0+/-5.1 kg x m2, respiratory disturbance index (RDI) 32.9+/-29 h), follow-up treatment was performed in 149 of them at 9, 18 and 30 months after CPAP prescription. Compliance with CPAP (machine run time/days CPAP available) was adjusted for the individual subjective sleep-time. Apnoea alleviation was defined as adjusted compliance multiplied by the CPAP effect (RDI with CPAP applied), remaining RDI was calculated. The baseline RDI, age or BMI in 75 patients, who did not tolerate nasal continuous positive airway pressure (nCPAP), did not differ from those accepting CPAP (acceptors, n=74). In acceptors at 9 months follow-up RDI with CPAP applied was 1.4+/-2.6 (CPAP effect, n=66), mean CPAP use was 3.6+/-2.5 x 24 h(-1) (n=68), mean apnoea alleviation was 52.4+/-32.0% (range 1-100%, n=47), the average remaining whole-night RDI was 17.8+/-26. At 9, 18 and 30 months (n=47), the mean daily CPAP use increased from 3.6+/-2.5 h to 4.1+/-2.5 h and 4.4+/-2.4 h (p<0.01). Effectiveness of continuous positive airway pressure is potentially high but acceptance was low. When accounting for sleep-time, its actual effect and use, only 50% adjusted continuous positive airway pressure effectiveness was observed.

A randomized, double-blind, placebo controlled, multi-center study of intravenous iron sucrose and placebo in the treatment of restless legs syndrome†

Iron deficiency may exacerbate symptoms in the Restless Legs Syndrome (RLS). We investigated the effect of intravenous iron sucrose or placebo on symptoms in patients with RLS and mild to moderate iron deficit. Sixty patients with primary RLS (seven males, age 46 (9) years, S‐ferritin ≤45 μg/L) recruited from a cohort of 231 patients were randomly assigned in a 12‐months double‐blind, multi‐centre study of iron sucrose 1000 mg (n = 29) or saline (n = 31). The primary efficacy variable was the RLS severity scale (IRLS) score at week 11. Median IRLS score decreased from 24 to 7 (week 11) after iron sucrose and from 26 to 17 after placebo (P = 0.123, N.S. for between treatment comparison). The corresponding scores at week 7 were 12 and 20 in the two groups (P = 0.017). Drop out rate because of lack of efficacy at 12 months was 19/31 after placebo and 5/29 patients after iron sucrose (Kaplan–Meier estimate, log rank test P = 0.0006) suggesting an iron induced superior long term RLS symptom control. Iron sucrose was well tolerated. This study showed a lack of superiority of iron sucrose at 11 weeks but found evidence that iron sucrose reduced RLS symptoms both in the acute phase (7 weeks) and during long‐term follow up in patients with variable degree of iron deficiency. Further studies on target patient groups, dosing and dosing intervals are warranted before iron sucrose could be considered for treatment of iron deficient patients with RLS.

Hypertension prevalence in obstructive sleep apnoea and sex: a population-based case–control study

Obstructive sleep apnoea (OSA) is a recognised risk factor for hypertension (HT). The current authors investigated confounders of this association in a sex-balanced community-based sample of patients with HT (n = 161) from the Skaraborg Hypertension and Diabetes Project (n = 1,149) and normotensive controls (n = 183) from an age and sex stratified community-based population sample (n = 1,109). All participants underwent ambulatory home polysomnography. Severe OSA (apnoea-plus-hypopnoea index (AHI) ≥30 events·h−1) was found in 47 and 25% of hypertensive and normotensive males, respectively. The corresponding numbers in females were 26 and 24%, respectively. The odds ratio (OR) for HT increased across AHI tertiles from 1.0 to 2.1 (95% confidence interval: 0.9–4.5) and 1.0 to 3.7 (95% CI: 1.7–8.2) in males, but not in females where the OR increased from 1.0 to 1.8 (95% CI: 0.8–3.9) and 1.0 to 1.6 (95% CI: 0.7–3.5). Regression analysis correcting for age, body mass index (or waist–hip ratio) and smoking did not eliminate the association between OSA and HT in males. The present data suggest that obstructive sleep apnoea is highly prevalent in both the general population and in patients with known hypertension. The contribution of obstructive sleep apnoea to hypertension risk may be sex dependent and higher in males than in females.

The effect of short-term withdrawal from continuous positive airway pressure therapy on sympathetic activity and markers of vascular inflammation in subjects with obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is commonly associated with cardiovascular disease and sympathetic activation. However, it is unclear whether this association is independent of obesity and to what extent treatment with nasal continuous positive airway pressure (CPAP) alleviates the vascular inflammation that underpins cardiovascular disease. We therefore evaluated whether short‐term withdrawal from CPAP therapy in subjects with moderate–severe OSA would result in increased levels of sympathetic activity and circulating inflammatory cytokines independent of weight. Vascular inflammatory markers (hsCRP, hsIL‐6 and hsTNF‐α) were assessed in 20 subjects after one and seven nights of withdrawal from CPAP together with the hypoxia‐responsive angiogenic marker VEGF and urinary catecholamines. Compared with baseline on CPAP, withdrawal from therapy resulted in an immediate return of OSA with an increase in RDI to 26.7 ± 5.2 and 39.0 ± 5.9 events per hour after one and seven nights without CPAP, respectively (both P < 0.0001). This was accompanied by a concomitant rise in daytime urinary noradrenaline (P < 0.0001) after seven nights CPAP withdrawal that was positively associated with the severity of hypoxaemia. In contrast, withdrawal from CPAP therapy was not accompanied by any change in measured cytokines or VEGF (all P > 0.1). In conclusion, 1 week of CPAP withdrawal was associated with a return of OSA and a marked increase in sympathetic activity without a concomitant elevation of vascular inflammatory markers.

Diabetes Mellitus Prevalence and Control in Sleep-Disordered Breathing: The European Sleep Apnea Cohort (ESADA) Study

BACKGROUND OSA is associated with an increased risk of cardiovascular morbidity. A driver of this is metabolic dysfunction and in particular type 2 diabetes mellitus (T2DM). Prior studies identifying a link between OSA and T2DM have excluded subjects with undiagnosed T2DM, and there is a lack of population-level data on the interaction between OSA and glycemic control among patients with diabetes. We assessed the relationship between OSA severity and T2DM prevalence and control in a large multinational population. METHODS We performed a cross-sectional analysis of 6,616 participants in the European Sleep Apnea Cohort (ESADA) study, using multivariate regression analysis to assess T2DM prevalence according to OSA severity, as measured by the oxyhemoglobin desaturation index. Patients with diabetes were identified by previous history and medication prescription, and by screening for undiagnosed diabetes with glycosylated hemoglobin (HbA1c) measurement. The relationship of OSA severity with glycemic control was assessed in diabetic subjects. RESULTS T2DM prevalence increased with OSA severity, from 6.6% in subjects without OSA to 28.9% in those with severe OSA. Despite adjustment for obesity and other confounding factors, in comparison with subjects free of OSA, patients with mild, moderate, or severe disease had an OR (95% CI) of 1.33 (1.04-1.72), 1.73 (1.33-2.25), and 1.87 (1.45-2.42) (P < .001), respectively, for prevalent T2DM. Diabetic subjects with more severe OSA had worse glycemic control, with adjusted mean HbA1c levels 0.72% higher in patients with severe OSA than in those without sleep-disordered breathing (analysis of covariance, P < .001). CONCLUSIONS Increasing OSA severity is associated with increased likelihood of concomitant T2DM and worse diabetic control in patients with T2DM.

Zaleplon shortens subjective sleep latency and improves subjective sleep quality in elderly patients with insomnia

Insomnia is a frequent complaint in the elderly population. Hypnotic agents, including benzodiazepines, with longer pharmacological half‐lives have been associated with side effects, including residual sedation, memory impairment, and discontinuation effects. Zaleplon is a short‐acting (elimination half‐life of 1 hour), non‐benzodiazepine hypnotic that acts on the benzodiazepine type 1 site of the gamma‐aminobutyric acid type A (GABAA) receptor complex. The pharmacology and pharmacokinetics of Zaleplon suggest a safety profile that is improved over other hypnotics. The objective of this placebo‐controlled study was to evaluate the efficacy and safety of Zaleplon (5 and 10 mg) in elderly (⩾65 years) outpatients with primary insomnia. This was a multicenter, double‐blind, randomised, placebo‐controlled 2‐week outpatient study. Postsleep questionnaires were used to record subjective sleep variables: sleep latency, sleep duration, number of awakenings, and sleep quality. Zaleplon significantly reduced subjective sleep latency during both weeks of the study with both 5‐ and 10‐mg doses. Subjective sleep quality was improved for significantly more patients treated with zaleplon 10 mg than those treated with placebo during both weeks of treatment. There was a weak indication of rebound insomnia after discontinuation of treatment with the 10‐mg dose, but no significant difference in common treatment–emergent adverse events across treatment groups. Zaleplon is an effective and safe hypnotic for the treatment of insomnia in the elderly. Copyright

The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea

Objective:Obstructive sleep apnoea (OSA) occurs frequently in obese patients and may be reversible with weight loss. Obstructive sleep apnoea and obesity are both independent risk factors for hypertension and increased sympathetic activity. Sibutramine has been increasingly used in the management of obesity, but is relatively contraindicated in patients with hypertension. No studies have investigated the effect of sibutramine on OSA, blood pressure and heart rate. We aimed to assess the changes in OSA and cardiovascular parameters in obese men with OSA enrolled in a sibutramine-assisted weight loss programme (SIB-WL).Design:Open uncontrolled cohort study of obese male subjects with OSA in an SIB-WL.Subjects:Eighty-seven obese (body mass index =34.2±2.8 kg/m2) middle-aged (46.3±9.3 years) male subjects with symptomatic OSA (Epworth score 13.4±3.6; respiratory disturbance index (RDI) 46.0±23.1 events/h) completed the study.Results:At 6 months, there was significant weight loss (8.3±4.7 kg, P<0.0001), as well as a reduction in waist and neck circumference and sagittal height (all P<0.0001). These changes were accompanied by a reduction in OSA severity (RDI fell by 16.3±19.4 events/h and Epworth score by 4.5±4.6), both P<0.0001). There was no significant change to systolic (P=0.07) or diastolic blood pressure (P=0.87); however, there was a mild rise in resting heart rate (P<0.0001).Conclusion:Moderate (∼10%) weight loss with SIB-WL results in improvement in OSA severity without increase in blood pressure in closely monitored OSA subjects.