The impact of obstructive sleep apnoea in extreme obesity: the impact on ethnicity, glycaemia and diabetes related microvascular complications

Obesity is known to be associated with obstructive sleep apnoea (OSA) and Type 2 diabetes mellitus (T2DM). The effect of OSA in very severely obese individuals is not well documented. In this thesis, I compared the effect of OSA in South Asians and white Europeans, examined the effect of OSA on glycaemic control among T2DM, and explored the relationship between OSA and diabetic retinal and kidney diseases in a severely obese population. I also systematically reviewed the effect of OSA on diabetic kidney and retinal diseases. Findings from this thesis were 1) severely obese South Asians had greater severity of OSA compared to white Europeans and the mechanisms mediating this require further investigation, 2) a high OSA prevalence in T2DM individuals with a positive relationship between nocturnal hypoxia and glycaemic control, 3) severity of hypoxaemia during sleep may be an important factor in the development of diabetic retinal complications, 4) duration of hypoxaemia during sleep were inversely associated with renal function in T2DM and 5) from the systematic review, there is a need for future large cohort studies with long term follow-up data to examine the long-term effects of OSA and other sleep parameters on diabetic retinal and kidney diseases

Tackling diabesity: weight management issues for people with type 2 diabetes

The World Health Organization has estimated that more than 600 million adults worldwide are now classified as obese, which is defined as a BMI of ≥30 kg/m2. The rising prevalence of obesity has led to a simultaneous increase in the prevalence of type 2 diabetes, and the term “diabesity” has been coined to describe those with type 2 diabetes and obesity. The aim of this review is to describe the prevalence of obesity and type 2 diabetes in Australia and summarise practical aspects of weight management. It will also explore the role of healthcare professionals in weight management and the prevention of the complications of diabesity

Secondary aorto-enteric fistula: a case report and review of literature

Aorto-enteric fistula (AEF) is an uncommon but potentially fatal condition that is important to identify early because early diagnosis and aggressive management can reduce mortality. We report the case of a 73-year-old man with a history of aorto-bifemoral bypass grafting who was admitted for investigation of tiredness and lethargy. He passed melaena on the day of admission with an associated drop in haemoglobin. Initial upper gastrointestinal endoscopy revealed no significant abnormality. Later in the admission he again passed melaena, this time in large amounts. A repeat endoscopy identified a defect in the duodenal mucosa with visible Dacron graft. The patient went on to suffer another large bleed from which he could not be resuscitated. Our report highlights a fatal manifestation of aorto-enteric fistula, and reviews the associated literature

The Association between Obstructive Sleep Apnea on Diabetic Kidney Disease:A Systematic Review and Meta-Analysis

STUDY OBJECTIVE: This systematic review aims to investigate the association between obstructive sleep apnea (OSA) and diabetic kidney disease (DKD). METHODS: MeSH terms and free text searches were performed on MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from inception to April 2015. Zetoc and OpenGrey databases were queried for grey literature, and lastly, hand searches were carried out. Study selection and quality assessment were conducted by two authors. One author carried out data extraction, which was checked by other authors. The relationships between apneahypopnea index (AHI), oxygen desaturation index (ODI), time spent under 90% oxygen saturation (%TST < 90), and minimum and mean oxygen saturation (O2) on DKD were examined. RESULTS: Two longitudinal and ten cross-sectional studies were included for our narrative synthesis, and seven studies for meta-analysis. Studies that performed multi-variable analysis demonstrated significant associations between OSA (assessed using either apnea-hypopnea index or ODI) and DKD in type 2 diabetes mellitus (T2DM). This was confirmed by meta-analysis (pooled OR 1.73, 95% CI: 1.13–2.64). There was some evidence to suggest that %TST < 90 may have an association with DKD. There was insufficient evidence to conclude on the relationship between minimum and mean oxygen saturation on DKD. There was no evidence available on the associations between OSA and other respiratory parameters in type 1 diabetes mellitus populations. CONCLUSIONS: There is moderate evidence that OSA is associated with DKD in patients with T2DM. Large prospective studies with long-term follow up are needed to assess the possible bi-directional mechanisms between OSA and DKD. CITATION: Leong WB, Jadhakhan F, Taheri S, Thomas GN, Adab P. The association between obstructive sleep apnea on diabetic kidney disease: a systematic review and meta-analysis. SLEEP 2016;39(2):301–308

The impact of hypoxemia on nephropathy in extremely obese patients with type 2 diabetes mellitus.

STUDY OBJECTIVES Diabetes mellitus (DM) is associated with obstructive sleep apnea (OSA) and nephropathy. The hypoxemia associated with OSA may exacerbate renal deterioration in DM nephropathy. We examined the role of hypoxemia in the development of DM nephropathy in severely obese patients. METHODS This cross-sectional study examined anonymized data from 90 DM patients with extreme obesity attending a weight management service. All patients underwent a routine overnight sleep study. Respiratory parameters measured included apnea-hypopnea index (AHI), mean and minimum oxygen (O2) saturations, and time spent under 90% O2 saturation (%TST < 90%). Chronic kidney disease (CKD+) was defined as estimated glomerular filtration rate (eGFR) ≤ 60 mL/min/1.73 m(2). RESULTS Twenty (22%) patients were CKD+. These patients were 7 years older (mean age ± SD 57 ± 11 years, p = 0.003) and had greater adiposity (mean body mass index [BMI] ± SD 50.6 ± 8.7 kg/m(2), p = 0.012). No significant differences were found for median AHI and minimum O2 saturation. %TST < 90% was 4 times greater in CKD+ group (p = 0.046). Multivariate regression analysis showed that AHI (β = -0.17, 95% CI: -0.316 to -0.024) and %TST < 90% (β = -0.215, 95% CI: -0.406 to -0.023) were negatively correlated with eGFR after adjustment for age, gender, BMI, comorbidities, insulin treatment, and drugs affecting the renin-angiotensin system. No associations were found between mean and minimum O2 saturations, and eGFR. CONCLUSION Apnea and hypopnea events as well as duration of nocturnal hypoxemia were inversely associated with renal function after adjusting for potential confounders. Given the significant burden of renal disease in diabetes, greater vigilance is required in identifying OSA in DM patients with extreme obesity

Sample characteristics of 93 patients according to presence/absence of obstructive sleep apnea.

<p>Data are presented as mean±standard deviation, number (%), or median (interquartile range).</p><p>OSA = obstructive sleep apnea; BMI = body mass index; CAD = coronary artery disease; DM = diabetes mellitus; BP = blood pressure; eGFR = estimated glomerular filtration rate.</p><p>p values were calculated using either independent t-test, chi square or Mann Whitney U-test.</p

Logistic regression analyses assessing the presence of diabetic retinopathy (DR) and maculopathy (DMac) with four respiratory parameters.

<p>Model 1: unadjusted.</p><p>Model 2: adjusted for age, gender, ethnicity.</p><p>Model 3: further adjusted for diabetes mellitus duration, insulin treatment, HbA_1c, hypertension, and coronary artery disease.</p>*<p>p<0.05;</p>**<p>p<0.01.</p

Diabetic retinopathy in 93 patients according to presence/absence of obstructive sleep apnea.

<p>OSA = obstructive sleep apnea.</p><p>p values derived from chi square test.</p

Hypoxemia and glycemic control in type 2 diabetes mellitus with extreme obesity.

CONTEXT Obstructive sleep apnea (OSA) has been shown to be associated with type 2 diabetes mellitus (DM). Studies on healthy individuals found that OSA is associated with lower insulin sensitivity. We hypothesized that nocturnal hypoxemia from OSA is associated with poorer glycemia in severely obese DM individuals. DESIGN AND SETTING This was a retrospective observational study of 122 non-DM, 126 non-insulin-treated DM, and 35 insulin-treated DM patients. Data were collected on demographic characteristics, body mass index, and comorbidities. An overnight sleep study was performed in all patients, and OSA was defined as an apnea-hypopnea index of ≥5 events/h. RESULTS There were more males (P = .003) and a lower proportion of white Europeans (P = .010) among DM patients. The prevalence of OSA was 80.1% in DM and 63.1% in non-DM individuals (P = .001). DM individuals also had lower oxygen saturation (O2) (P = .0106), greater percentage of time spent under 90% oxygen saturation (%TST<90%) (P = .0067), and higher apnea-hypopnea index (P = .0085). Regression analysis showed that %TST<90% and minimum O2 saturations were associated with worse hemoglobin A1c results among DM individuals. Every 10% reduction in minimum O2 was associated with a 0.3% increase in HbA1c, whereas a 10% increase in %TST<90% was associated with a 0.2% increase in hemoglobin A1c after adjusting for a range of potential confounders. CONCLUSION The high OSA prevalence in DM individuals and a positive relationship between nocturnal hypoxemia and glycemia supports the need to assess correction of hypoxemia as a management strategy for glycemic control