Weight and metabolic effects of cpap in obstructive sleep apnea patients with obesity

<p>Abstract</p> <p>Background</p> <p>Obstructive sleep apnea (OSA) is associated with obesity, insulin resistance (IR) and diabetes. Continuous positive airway pressure (CPAP) rapidly mitigates OSA in obese subjects but its metabolic effects are not well-characterized. We postulated that CPAP will decrease IR, ghrelin and resistin and increase adiponectin levels in this setting.</p> <p>Methods</p> <p>In a pre- and post-treatment, within-subject design, insulin and appetite-regulating hormones were assayed in 20 obese subjects with OSA before and after 6 months of CPAP use. Primary outcome measures included glucose, insulin, and IR levels. Other measures included ghrelin, leptin, adiponectin and resistin levels. Body weight change were recorded and used to examine the relationship between glucose regulation and appetite-regulating hormones.</p> <p>Results</p> <p>CPAP effectively improved hypoxia. However, subjects had increased insulin and IR. Fasting ghrelin decreased significantly while leptin, adiponectin and resistin remained unchanged. Forty percent of patients gained weight significantly. Changes in body weight directly correlated with changes in insulin and IR. Ghrelin changes inversely correlated with changes in IR but did not change as a function of weight.</p> <p>Conclusions</p> <p>Weight change rather than elimination of hypoxia modulated alterations in IR in obese patients with OSA during the first six months of CPAP therapy.</p

Melatonin prevents hyperglycemia in a model of sleep apnea

Objective: Obstructive sleep apnea is a common disorder associated with aging and obesity. Apneas cause repeated arousals, intermittent hypoxia, and oxidative stress. Changes in glucolipidic profile occur in apnea patients, independently of obesity. Animal models of sleep apnea induce hyperglycemia. This study aims to evaluate the effect of the antioxidants melatonin and N-acetylcysteine on glucose, triglyceride, and cholesterol levels in animals exposed to intermittent hypoxia. Materials and methods: Two groups of Balb/c mice were exposed to intermittent hypoxia (n = 36) or sham intermittent hypoxia (n = 36) for 35 days. The intermittent hypoxia group underwent a total of 480 cycles of 30 seconds reducing the inspired oxygen fraction from 21% to 7 ± 1% followed by 30 seconds of normoxia, during 8 hours daily. Melatonin or N-acetylcysteine were injected intraperitonially daily from day 21 on. Results: At day 35, glucose levels were significantly higher in the intermittent hypoxia group than in the control group. The intermittent hypoxia groups receiving N-acetylcysteine and vehicle showed higher glucose levels than the group receiving melatonin. The lipid profile was not affected by intermittent hypoxia or antioxidant administration. Conclusions: The present results suggest that melatonin prevents the well-recognized increase in glucose levels that usually follows exposure to intermittent hypoxia. Further exploration of the role of melatonin in sleep apnea is warranted

Ethnic minority disparities in progression and mortality of pre-dialysis chronic kidney disease : a systematic scoping review

Background: There are a growing number of studies on ethnic differences in progression and mortality for pre-dialysis chronic kidney disease (CKD), but this literature has yet to be synthesised, particularly for studies on mortality. Methods: This scoping review synthesized existing literature on ethnic differences in progression and mortality for adults with pre-dialysis CKD, explored factors contributing to these differences, and identified gaps in the literature. A comprehensive search strategy using search terms for ethnicity and CKD was taken to identify potentially relevant studies. Nine databases were searched from 1992 to June 2017, with an updated search in February 2020. Results: 8059 articles were identified and screened. Fifty-five studies (2 systematic review, 7 non-systematic reviews, and 46 individual studies) were included in this review. Most were US studies and compared African-American/Afro-Caribbean and Caucasian populations, and fewer studies assessed outcomes for Hispanics and Asians. Most studies reported higher risk of CKD progression in Afro-Caribbean/African-Americans, Hispanics, and Asians, lower risk of mortality for Asians, and mixed findings on risk of mortality for Afro-Caribbean/African-Americans and Hispanics, compared to Caucasians. Biological factors such as hypertension, diabetes, and cardiovascular disease contributed to increased risk of progression for ethnic minorities but did not increase risk of mortality in these groups. Conclusions: Higher rates of renal replacement therapy among ethnic minorities may be partly due to increased risk of progression and reduced mortality in these groups. The review identifies gaps in the literature and highlights a need for a more structured approach by researchers that would allow higher confidence in single studies and better harmonization of data across studies to advance our understanding of CKD progression and mortality

The effect of continuous positive airway pressure on glucose excursions in diabetics with sleep-disordered breathing: the results of continuous glucose monitoring

Sleep-disordered breathing (SDB) is often associated with impaired glucose metabolism. The study aimed at assessing immediate effect of CPAP on glucose excursions in type 2 diabetic patients with SDB measured with 72-hour continuous glucose monitoring system (CGMS). 8 type 2 diabetic patients with SDB (men, age 48,13±4,91 years, BMI 34,06±7,41 kg·m–2, HbA1c 7,3±1,4%) underwent 2 overnight polysomnographic examinations including diagnostic night and CPAP night. CGMS was applied on both occasions. Statistical analyses included paired Student's t-test. CPAP decreased apnoea-hypopnoea index (AHI) from 57,64±9,64·h–1 to 8,05±4,42·h–1 (p<0,0001) with significant improvement of saturation. Frequent episodes of sleep apnoea/hypopnoea and severe oxygen desaturation were followed by significant rise in blood glucose of up to 12,3 mmol·l–1. Duration of post-hypoxic hyperglycemia was 50±10,79 min and its climax tended to be appeared up to 45min post-hypoxia. Nocturnal hyperglycemia strongly correlated with severe oxygen desaturation. Nocturnal glucose values were significantly higher during diagnostic night than during CPAP night (8,19±0,99 mmol·l–1 versus 6,77±1,47 mmol·l–1; p<0,0001). CGMS also showed improved preprandial and 1,5-hour postprandial glucose levels for breakfast after CPAP night. The improvement in overall glucose levels was much greater in patients with BMI<30 kg·m–2 than in more obese patients. The results suggest that nocturnal hyperglycemia is closely related to desaturation and CPAP treatment may have an immediate decreasing effect on blood glucose in type 2 diabetic patients with SDB