| 1. |
- Grunstein, R R, et al.
(författare)
-
Impact of obstructive sleep apnea and sleepiness on metabolic and cardiovascular risk factors in the Swedish Obese Subjects (SOS) Study.
- 1995
-
Ingår i: International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity. - 0307-0565. ; 19:6, s. 410-8
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine if obstructive sleep apnea (OSA) is independently associated with cardiovascular risk factors and health status in subjects with severe obesity. DESIGN: Cross-sectional analysis of epidemiological data. SUBJECTS: 3034 participants in the Swedish Obese Subjects (SOS) Cohort. Two sub-groups with a high and low likelihood for OSA based on questionnaire data were analysed in detail. MEASUREMENTS: General health questionnaires, anthropometric data including CT calibrated values for body fat distribution and lean body mass, blood pressure, fasting insulin, triglycerides, cholesterol, uric acid, glucose. RESULTS: Self-reported loud snoring and observed breathing pauses (high likelihood of OSA) was associated with increased frequency of WHO Grade 4 dyspnea, admissions to hospital with chest pain, myocardial infarction, blood pressure, fasting insulin, fasting triglyceride (women only), uric acid (women only) after adjustment for body fat distribution and other potential confounders. CONCLUSION: OSA may be another medical disorder which contributes to morbidity in severe obesity and is associated with some of the components of the metabolic syndrome observed in the centrally obese.
|
|
| 2. |
- Grunstein, R R, et al.
(författare)
-
Impact of self-reported sleep-breathing disturbances on psychosocial performance in the Swedish Obese Subjects (SOS) Study.
- 1995
-
Ingår i: Sleep. - 0161-8105. ; 18:8, s. 635-43
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with severe obesity commonly have obstructive sleep apnea (OSA). In order to determine the impact of OSA on psychosocial morbidity in severe obesity, subjects enrolled in the Swedish Obese Subjects (SOS) Study were classified into two subgroups based on questionnaire data: one group with a high likelihood and one with a low likelihood of OSA. These groups were contrasted and multivariable analysis was used to examine whether OSA had independent effects on divorce rate, sick leave, work performance, income and self-estimated general health after adjustment for obesity, fat distribution, alcohol, smoking, medications and coexisting medical conditions. A high likelihood of OSA was identified in 338 men and 155 women, compared with 216 men and 481 women who had a low likelihood of OSA. Men with OSA were identical in age to men without OSA and had slightly higher levels of visceral fat (p = 0.01), but were similar in most psychosocial variables except self-perceived general health. Women with OSA were identical in age and visceral fat mass to women without OSA, but were characterized by a higher rate of impaired work performance, sick leave and divorce. When frequent sleepiness was used as an additional discriminator between OSA and non-OSA groups, marked differences in psychosocial morbidity were observed. Multivariable analysis revealed either OSA or frequent sleepiness or both to be independent predictors of amount of sick leave, worse self-rated general health, impaired work performance and divorce rate. Therefore OSA, measured by self report, is an important independent predictor of psychosocial morbidity in subjects with severe obesity.
|
|
| 3. |
- Phillips, C. L., et al.
(författare)
-
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
- 2007
-
Ingår i: J Sleep Res. - 0962-1105. ; 16:2, s. 217-25
-
Tidskriftsartikel (refereegranskat)abstract
- 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-alpha) 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.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Yee, B. J., et al.
(författare)
-
The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea
- 2007
-
Ingår i: Int J Obes (Lond). - : Springer Science and Business Media LLC. - 0307-0565. ; 31:1, s. 161-168
-
Tidskriftsartikel (refereegranskat)abstract
- 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/m(2)) 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 ( approximately 10%) weight loss with SIB-WL results in improvement in OSA severity without increase in blood pressure in closely monitored OSA subjects.International Journal of Obesity (2007) 31, 161-168. doi:10.1038/sj.ijo.0803363; published online 2 May 2006.
|
|
| 7. |
- Grunstein, Ronald R, et al.
(författare)
-
Two year reduction in sleep apnea symptoms and associated diabetes incidence after weight loss in severe obesity.
- 2007
-
Ingår i: Sleep. - 0161-8105. ; 30:6, s. 703-10
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY OBJECTIVES: To evaluate the effect of bariatric surgery on sleep apnea symptoms and obesity-associated morbidity in patients with severe obesity. DESIGN: Prospective study. SETTING: University hospitals and community centers in Sweden. Intervention: We investigated the influence of weight loss surgery (n=1729) on sleep apnea symptoms and obesity-related morbidity using a conservatively treated group (n=1748) as a control. MEASUREMENTS AND RESULTS: Baseline BMI in surgical group (42.2+/-4.4 kg/m(2)) and control group (40.1+/-4.6 kg/m(2)) changed -9.7+/-5 kg/m(2) and 0+/-3 kg/m(2), respectively, at 2-year follow-up. In the surgery group, there was a marked improvement in all obstructive sleep apnea (OSA) symptoms compared with the control group (P <0.001). Persistence of snoring (21.6 vs 65.5%, adjusted OR 0.14, 95% CI 0.10-0.19) and apnea (27.9 vs 71.3%, adjusted OR 0.16, 95% I 0.10-0.23) were much less in the surgery group compared with controls. Compared with subjects with no observed apnea at follow-up (n=2453), subjects who continued to have or developed observed apnea (n=404) had a higher incidence of diabetes (adjusted OR 2.03, 95% CI 1.19-3.47) and hypertriglyceridemia (adjusted OR 1.86, 95% CI 1.07-3.25) but not hypertension (adjusted OR 1.09, 95% CI 0.65-1.83) or hypercholesterolemia (adjusted OR 0.91, 95% CI 0.53-1.58). CONCLUSION: Bariatric surgery results in a marked improvement in sleep apnea symptoms at 2 years. Despite adjustment for weight change and baseline central obesity, subjects reporting loss of OSA symptoms had a lower 2-year incidence of diabetes and hypertriglyceridemia. Improvement in OSA in patients losing weight may provide health benefits in addition to weight loss alone.
|
|
| 8. |
- Hellgren, Johan, 1965, et al.
(författare)
-
Altered positional regulation of nasal patency in patients with obstructive sleep apnoea syndrome.
- 2009
-
Ingår i: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery. - : Springer Science and Business Media LLC. - 1434-4726. ; 266:1, s. 83-7
-
Tidskriftsartikel (refereegranskat)abstract
- We assessed the regulation of nasal patency supine in subjects with obstructive sleep apnoea syndrome (OSAS) compared to healthy controls. Healthy subjects increase nasal obstruction when changing body position from sitting to supine, possibly due to increased hydrostatic pressure in the head supine. Limited data indicate that this response is altered in patients with OSAS, suggesting that supine nasal patency is actively regulated. This study examined the nasal response to recumbent body position using acoustic rhinometry in OSAS patients and healthy controls. Twenty subjects (16 men and 4 women, mean age 55 +/- 16 years), with diagnosed OSAS [mean apnoea hypopnoea index (AHI) 46 +/- 22 events/h] without nasal obstruction and continuous positive airway pressure (CPAP)-naive, underwent measurement of intra-nasal cross sectional area by acoustic rhinometry at sitting and after 5 min supine. Twenty healthy controls (13 men, 7 women, mean age 35 +/- 9 years) were also included in the study. In the patients with OSAS, the mean minimal cross sectional area (MCA, left + right nasal cavity) was unchanged between sitting (1.18 +/- 0.41 cm(2)) and supine (1.21 +/- 0.35 cm(2), P = 0.5). In the healthy controls, the mean MCA decreased from 1.06 +/- 0.18 to 0.94 +/- 0.21 cm(2) supine, P = 0.01. This study showed that the normal decrease in nasal patency following a change in body position from sitting to supine is absent in patients with OSAS. The results indicate that there is an active regulation of supine nasal patency.
|
|
| 9. |
- Marshall, N.S., et al.
(författare)
-
Changes in sleep duration and changes in weight in obese patients: The Swedish Obese Subjects Study
- 2010
-
Ingår i: Sleep and Biological Rhythms. - : Springer Science and Business Media LLC. - 1479-8425 .- 1446-9235. ; 8:1, s. 63-71
-
Tidskriftsartikel (refereegranskat)abstract
- Sleep duration has been linked to obesity and/or weight gain in a number of cross-sectional and longitudinal observational studies. The Swedish Obese Subjects Study (SOS) is a non-randomized controlled trial of surgical interventions (surgical group) for weight-loss compared with standard conservative weight loss management (control group). We investigated whether changes in sleep duration were associated with weight loss in severely obese patients. This is a longitudinal treatment study reanalyzed as two 10-year cohorts, surgical (n= 1139) and control (n= 952). Self-reported habitual sleep duration, body weight, total cholesterol, HDL (high density lipoprotein) cholesterol, triglycerides, fasting glucose, and blood pressure were measured at baseline, 2 years, and 10 years. At baseline patients were obese (inclusion: body mass index [BMI]≥34 for men and ≥38 for women) and middle aged (37–60 years). The surgical group had substantially greater weight reduction after 10 years (–19.1 kg) compared with the control group (+1.2 kg). Changes in sleep duration between baseline, 2 years, and 10 years were not associated with body mass or with changes in weight in either cohort. Changes in cardiovascular disease (CVD) risk factors were not associated with changes in sleep duration. Changes in sleep duration over 2 and 10 years were not associated with weight loss in these obese patients. The data from the SOS study offers no support to the hypothesis that sleep-duration modification is associated with obesity reduction in severely obese people.
|
|
| 10. |
- Marshall, N.S., et al.
(författare)
-
Self-reported sleep apnoea and mortality in patients from the Swedish Obese Subjects study
- 2011
-
Ingår i: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 38:6, s. 1349-1354
-
Tidskriftsartikel (refereegranskat)abstract
- Sleep apnoea is associated with increased mortality in sleep clinic and community population groups. It is unclear whether a clinical report of sleep apnoea results in additional mortality risk in patients with severe obesity. The Swedish Obese Subjects (SOS) study is a nonrandomised controlled trial of bariatric surgery versus conventional treatment for the treatment of severe obesity and its complications (mean±sd body mass index 41±5 kg·m−2). The presence or absence of sleep apnoea (witnessed pauses in breathing) was determined by self-reporting at baseline in 3,953 patients who were observed for 54,236 person-yrs (mean 13.5 maximum 21.0 yrs). Sleep apnoea was reported by 934 (23.6%) patients at baseline and was a significant univariate predictor of mortality (hazard ratio (95% CI) 1.74 (1.40–2.18)). In a range of multivariate models of mortality risk, controlling for ≤16 other potential confounders and established mortality risk factors, sleep apnoea remained a significant prognostic factor (fully adjusted model 1.29 (1.01–1.65)). Self-reported sleep apnoea is an independent prognostic marker of all-cause mortality in obese patients.
|
|
| 11. |
- Phillips, C., et al.
(författare)
-
Diurnal and obstructive sleep apnea influences on arterial stiffness and central blood pressure in men
- 2005
-
Ingår i: Sleep. ; 28:5
-
Tidskriftsartikel (refereegranskat)abstract
- STUDY OBJECTIVES: Nocturnal and early morning elevation of blood pressure are common acute manifestations of obstructive sleep apnea (OSA) that do not always carry over into a sustained daytime hypertension. Using pulse wave analysis, we examined the effect of OSA on arterial stiffness and central aortic blood pressure to assess whether each would be elevated independent of diurnal changes in peripheral blood pressure. DESIGN: Cross-sectional sleep laboratory cohort study. SETTING: Two university teaching hospitals. PATIENTS: 57 male nonsmokers referred for suspected OSA and free of known cardiovascular disease or blood-pressure and lipid-lowering medications. MEASUREMENTS AND RESULTS: The augmentation index, a quantification of augmentation of central aortic pressure due to the reflected component of the pulse pressure waveform, and brachial and aortic blood pressure were determined in the evening and early morning. The augmentation index consistently increased from evening to morning (P < .001) and was accompanied by an increase in central systolic blood pressure (P = .007) and a decrease in pulse pressure amplification (P < .001). However, these changes were unaccompanied by any changes in peripheral blood pressure. Overnight changes in mean blood pressure and heart rate were the only predictors of this effect, but they only accounted for a third of the variance (r2 = 0.339, P = .002). After adjustment for known confounders, the respiratory disturbance index was positively correlated with augmentation index at both time points (PM: P = .008, am: P = .016). The respiratory disturbance index did not correlate with any indexes of peripheral or central blood pressure. CONCLUSIONS: Systemic arterial stiffness is positively correlated with OSA severity and, in addition, is increased in magnitude in the early morning independent of OSA severity.
|
|
| 12. |
- Phillips, Craig L, et al.
(författare)
-
Effects of continuous positive airway pressure treatment and withdrawal in patients with obstructive sleep apnea on arterial stiffness and central BP.
- 2008
-
Ingår i: Chest. - : Elsevier BV. - 0012-3692. ; 134:1, s. 94-100
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Obstructive sleep apnea (OSA) is associated with increased BP and other cardiometabolic risk factors. The aim of the present study was to determine whether arterial stiffness and central BP (two important cardiovascular risk factors) would change, independent of peripheral BP following either the initiation of or withdrawal from nasal continuous positive airway pressure (CPAP) treatment in subjects with OSA. METHODS AND RESULTS: Arterial stiffness and peripheral and central BP were measured at baseline, and then either at 2 months after starting CPAP therapy (intervention group, n=20) or 7 nights after withdrawal from CPAP therapy (withdrawal group, n=20) using pulse wave analysis. In the intervention group, there were reductions in arterial stiffness (ie, the aortic augmentation index fell by 2.5%) and central systolic BP (fell by 4.2 mm Hg) without a concomitant reduction in peripheral BP. The change in arterial stiffness was associated with CPAP compliance (r=-0.47). In contrast, in the withdrawal group there were no overall changes in arterial stiffness or BP. However, there was an early morning increase in diastolic BP and heart rate relative to late evening. CONCLUSION: These results suggest that clinically important changes in arterial stiffness and central BP may occur following effective CPAP treatment of OSA without parallel changes in peripheral BP.
|
|
| 13. |
- Stenlöf, Kaj, 1965, et al.
(författare)
-
Energy expenditure in obstructive sleep apnea: effects of treatment with continuous positive airway pressure.
- 1996
-
Ingår i: The American journal of physiology. - 0002-9513. ; 271:6 Pt 1
-
Tidskriftsartikel (refereegranskat)abstract
- We examined 24-h energy expenditure (EE) in a chamber for indirect calorimetry in five male patients with obstructive sleep apnea (OSA) and six snoring control subjects (snorers). The 24-h EE was remeasured in patients with OSA after 3-mo treatment with nasal continuous positive airway pressure (CPAP). Patients with OSA had a greater degree of severe sleep-breathing disturbance than snorers. Patients with OSA had higher 24-h EE [39.2 +/- 3.0 vs. 33.9 +/- 2.7 kcal.24 h-1.kg fat-free mass (FFM)-1, P < 0.05], daytime urinary norepinephrine and vanillylmandelic acid (VMA), and aminoterminal procollagen III peptide (PIIIp) levels, and they tended to have higher sleeping EE (32.4 +/- 4.1 vs. 26.3 +/- 1.9 kcal.24 h-1.kg FFM-1, P < 0.1) than snorers. CPAP treatment normalized sleep architecture and breathing. CPAP treatment also decreased sleep EE (from 32.4 +/- 4.1 to 27.2 +/- 1.4 kcal.24 h-1.kg FFM-1, P < 0.05) and EE variability during sleep (from 1.6 +/- 0.5 to 1.0 +/- 0.5 kcal.24 h-1.kg FFM-1, P < 0.05) and increased the basal metabolic rate-to-sleep EE ratio in all subjects. Serum PIIIp and plasma norepinephrine decreased after CPAP in all patients. We conclude that OSA is associated with an increased sleep EE, which is normalized by treatment with CPAP.
|
|
| 14. |
- Theorell-Haglöw, Jenny, et al.
(författare)
-
Associations Between Obstructive Sleep Apnea and Measures of Arterial Stiffness
- 2019
-
Ingår i: Journal of Clinical Sleep Medicine (JCSM). - : AMER ACAD SLEEP MEDICINE. - 1550-9389 .- 1550-9397. ; 15:2, s. 201-206
-
Tidskriftsartikel (refereegranskat)abstract
- Study Objectives: The aim of this study was to determine whether severity measures of obstructive sleep apnea (OSA) are associated with arterial stiffness and central blood pressure (two important cardiovascular risk factors) in a large group of patients with OSA. Methods: Baseline data from six studies on OSA in which arterial stiffness and central aortic blood pressure measures were determined using applanation tonometry were pooled. Associations between measures of arterial stiffness (heart rate corrected augmentation index [AI75]), central aortic blood pressure (central systolic pressure [CSP] and heart rate corrected central augmentation pressure [CAP75]) and measures of OSA severity were explored using stepwise regression modelling. Results: Data from 362 participants (M:F ratio 13:1) with mean (standard deviation) age 49.2 (11.0) years, body mass index 31.9 (5.3) kg/m(2), apnea-hypopnea index (AHI) 35.7 (20.7) events/h were included in the analyses. The AHI, oxygen desaturation index (ODI3%), and sleep time with SpO(2) < 90% (T90) were all associated with arterial stiffness (AI75), (AHI: adj. beta = .069; P = .01; ODI3%: adj. beta = .072; P = .01; T90: adj. beta = .18; P < .0001) and CAP75 (AHI: adj. beta = .030; P = .01; ODI3%: adj. beta = .027; P = .02; T90: adj. beta = .080; P < .0001). AHI was also associated with CSP (AHI: adj. beta = .11; P = .002). Conclusion: OSA severity was significantly associated with augmentation index and CAP75 although the relationships were not strong.
|
|
| 15. |
- Theorell-Haglöw, Jenny, et al.
(författare)
-
Changes of vitamin D levels and bone turnover markers after CPAP therapy : a randomized sham-controlled trial
- 2018
-
Ingår i: Journal of Sleep Research. - : WILEY. - 0962-1105 .- 1365-2869. ; 27:4
-
Tidskriftsartikel (refereegranskat)abstract
- The aim was to investigate whether continuous positive airway pressure treatment could modulate serum vitamin D (25-hydroxyvitamin D) and bone turnover markers (collagen-type 1 cross-linked C-telopeptide, osteocalcin and N-terminal propeptide of type 1 collagen) in secondary analysis from a randomized controlled trial. Sixty-five continuous positive airway pressure-naive male patients with obstructive sleep apnea (age=49 +/- 12years, apnea-hypopnea index=39.9 +/- 17.7events h(-1), body mass index=31.3 +/- 5.2kgm(-2)) were randomized to receive either real (n=34) or sham (n=31) continuous positive airway pressure for 12weeks. At 12weeks, all participants received real continuous positive airway pressure for an additional 12weeks. After 12weeks of continuous positive airway pressure (real versus sham), there were nobetween-group differences for any of the main outcomes [25-hydroxyvitamin D: -0.80 +/- 5.28ngmL(-1) (mean +/- SE) versus 3.08 +/- 3.66ngmL(-1), P=0.42; collagen-type 1 cross-linked C-telopeptide: 0.011 +/- 0.014ngmL(-1) versus -0.004 +/- 0.009ngmL(-1), P=0.48; osteocalcin: 1.13 +/- 1.12ngmL(-1) versus 0.46 +/- 0.75ng mL(-1), P=0.80; N-terminal propeptide of type 1 collagen: 2.07 +/- 3.05gL(-1) versus -1.05 +/- 2.13gL(-1), P=0.48]. There were no further differences in subgroup analyses (continuous positive airway pressure-compliant patients, patients with severe obstructive sleep apnea or sleepy patients). However, after 24weeks irrespective of initial randomization, vitamin D increased in patients with severe obstructive sleep apnea (9.56 +/- 5.51ngmL(-1), P=0.045) and in sleepy patients (14.0 +/- 4.69ngmL(-1), P=0.007). Also, there was a significant increase in osteocalcin at 24weeks (3.27 +/- 1.06ngmL(-1), P=0.01) in compliant patients. We conclude that 12weeks of continuous positive airway pressure did not modulate vitamin D or modulate any of the bone turnover markers compared with sham. However, it is plausible that continuous positive airway pressure may have late beneficial effects on vitamin D levels and bone turnover markers in selected groups of patients with obstructive sleep apnea.
|
|
| 16. |
- Theorell-Haglöw, Jenny, et al.
(författare)
-
Gender differences in obstructive sleep apnoea, insomnia and restless legs syndrome in adults - What do we know? : A clinical update
- 2018
-
Ingår i: Sleep Medicine Reviews. - : Saunders Elsevier. - 1087-0792 .- 1532-2955. ; 38, s. 28-38
-
Forskningsöversikt (refereegranskat)abstract
- Research in sleep medicine over the last decades has involved a broad variety of sleep disorders in both men and women. Gender differences have been identified in sleep physiology as well as in the three most common sleep disorders: obstructive sleep apnoea (OSA), insomnia and restless legs syndrome (RLS). However, research on gender differences in sleep medicine appears limited. This clinical review aims to give an updated overview of gender differences, in relation to prevalence, clinical presentation, treatment and quality of life in OSA, insomnia and RLS. Future research directions in the adult population will also be discussed. (C) 2017 Elsevier Ltd. All rights reserved.
|
|
| 17. |
- Vedam, Hima, et al.
(författare)
-
Short-term hypoxia reduces arterial stiffness in healthy men.
- 2009
-
Ingår i: European journal of applied physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 105:1, s. 19-25
-
Tidskriftsartikel (refereegranskat)abstract
- This study examined the effects of hypoxia (80% arterial oxyhaemoglobin saturation for 20 min) and the accompanying changes in heart rate and blood pressure on two components of arterial stiffness in healthy men. Augmentation index (AIx) and time to reflection (Tr) representing measures of muscular artery and aortic stiffness, respectively, were continuously measured. At first, subjects were exposed to either hypoxia (n = 12) or room air (n = 5). During early hypoxia AIx increased by 6% before decreasing to baseline. After hypoxia AIx decreased by a further 6%. In contrast there was no change in Tr. Six subjects were then exposed to hypoxia following infusion with the nitric oxide (NO) synthase inhibitor NG-mono-methyl-L: -arginine (L-NMMA) or saline. During hypoxia AIx decreased by 12% following saline but increased by 14% after L-NMMA and Tr did not change. These findings suggest that hypoxia may induce NO-mediated vasodilatation of small muscular arteries but not the aorta.
|
|
