Validation of a Novel Screening Tool for Obstructive Sleep Apnoea in Bariatric Surgery Candidates

Undiagnosed obstructive sleep apnoea (OSA) is increasingly recognised as a serious post-operative risk with bariatric surgery. Demand for pre-operative screening for OSA in bariatric surgery candidates is rising and there is a need for simple, cost-effective screening methods to mitigate the stain on Sleep Services. WatchPAT is a relatively new device, which uses peripheral arterial tonometry rather than airflow to estimate the apnoea hypopnoea index (AHI). While WatchPAT use is increasing in the general sleep clinic population it has not yet been validated in patients with a BMI >35, i.e. the target population in bariatric surgery. The studies described in this thesis aim to validate WatchPAT against the clinical gold-standard in patients on the bariatric pathway and to assess patient acceptability of WatchPAT. 28 bariatric surgery candidates (22 female/6 male, mean ± SD age 44.1 ± 11.6 years, BMI 45.7 ± 7.5 kg/m2) wore WatchPAT 300 and Embletta MPR simultaneously for one night and the outcome measure, AHI was compared in the two devices. AHI was higher in WatchPAT than Embletta (Median (range) 23.5 (3.9-70.6) versus 11.7 (0.7-46.5) events per hour; z=-4.623, p=0.000). There was a strong positive correlation between WatchPAT and Embletta AHI measurements (r=0.849; p=0.000). Bland Altman plots revealed a systematic bias; differences diverging at higher AHI values. ROC plots were constructed for a range of AHI cut-offs; AUC was highest for an AHI ≥20 (0.986), ≥15 (0.947) and AHI ≥30 (0.979), while for AHI ≥5 the AUC was 0.850. 97% of respondents reported that WatchPAT would be acceptable to them if introduced into the bariatric surgery pathway. These results are similar to those in the non-bariatric sleep clinic population and suggest that WatchPAT may suitable for use in bariatric surgery patients requiring screening for OSA though further larger scale studies are needed to confirm these findings before incorporating into clinical guidelines

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Obstructive Sleep Apnea Syndrome Is Associated with Deficits in Verbal but Not Visual Memory

Rationale: Although cognitive deficits are well documented in patients with sleep apnea, the impact on memory remains unclear

U-shaped relationship of leukocyte telomere length with all-cause and cancer-related mortality in older men

Background: Telomeres are essential DNA-protein complexes whose attrition results in cellular dysfunction and senescence. Leukocyte telomere length (LTL) correlates with tissue telomere length, representing a biomarker for biological age. However, its predictive value for mortality risk, and for cardiovascular versus cancer deaths, in older adults remains uncertain. Method: We studied 3608 community-dwelling men aged 77.0 ± 3.6 years. Leukocyte telomere length was measured using multiplex quantitative PCR, expressed as amount of telomeric DNA relative to single-copy control gene (T/S ratio). Deaths from any cause, cardiovascular disease (CVD), and cancer were ascertained using data linkage. Curve fitting used restricted cubic splines and Cox regression analyses adjusted for age, cardiometabolic risk factors, and prevalent disease. Results: There was a U-shaped association of LTL with all-cause mortality. Men with T/S ratio in the middle quartiles had lower mortality (quartiles, Q2 vs Q1, hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.77-0.97, p = .012; Q3 vs Q1 HR = 0.88, CI 0.79-0.99, p = .032). There was no association of LTL with CVD mortality. There was a U-shaped association of LTL with cancer mortality. Men with LTL in the middle quartiles had lower risk of cancer death (Q2 vs Q1, HR = 0.73, CI 0.59-0.90, p = .004; Q3 vs Q1, HR = 0.75, CI 0.61-0.92, p = .007). Conclusions: In older men, both shorter and longer LTL are associated with all-cause mortality. A similar U-shaped association was seen with cancer deaths, with no association found for cardiovascular deaths. Further research is warranted to explore the prognostic utility of LTL in ageing

Associations of plasma IGF1, IGFBP3 and estradiol with leucocyte telomere length, a marker of biological age, in men

Objective: Effects of insulin-like growth factor 1 (1GF1) and its binding proteins (IGFBPs) on ageing, and their interaction with sex hormones, remain uncertain. We examined associations of plasma IGF1, IGFBP1, IGFBP3, estradiol and testosterone, with leucocyte telomere length (LTL), a marker of biological age, in 2999 community-dwelling men aged 70-84 years. Methods: Plasma IGF1, IGFBP1 and IGFBP3 measured using immunoassay, sex hormones using mass spectrometry. LTL measured by PCR, expressed as ratio of telomeric to single-copy control gene DNA (T/S ratio). Linear regression models adjusted for age and cardio-metabolic risk factors, median splits defined low/high groups. Results: Mean age was 76.7 ± 3.2 years. IGF1 and IGFBP3 showed age-adjusted correlations with LTL (coefficient 0.59, P = 0.001 and 0.45, P = 0.013 respectively), IGFBP1 did not. In multivariable-adjusted models IGF1 and IGFBP3 (but not IGFBP1) were associated with LTL (T/S ratio 0.015 higher per 1 S.D. increase in IGF1, P = 0.007, and 0.011 per 1 S.D. IGFBP3, P = 0.049). IGF1 and estradiol were independently associated with longer telomeres (T/S ratio 0.012 higher per 1 S.D. increase in estradiol, P= 0.027, when included in model with IGF1). Testosterone was not associated with LTL. Men with both high IGF1 (>133 μg/L) and high estradiol (>70 pmol/L) had longer LTL compared to men with lower values (multivariable-adjusted T/S ratio 1.20 vs 1.16, P = 0.018). Conclusions: Higher IGF1 and IGFBP3 are independently associated with longer telomeres in older men. Additive associations of higher IGF1 and higher estradiol with telomere length are present. Further studies are needed to determine whether these hormonal exposures cooperate to slow biological aging