scholarly journals Minimum Threshold of Bariatric Surgical Weight Loss for Initial Diabetes Remission

2021 ◽  
Author(s):  
Douglas Barthold ◽  
Elizabeth Brouwer ◽  
Lee J. Barton ◽  
David E. Arterburn ◽  
Anirban Basu ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Weight Loss ◽  
Proportional Hazards ◽  
Reference Group ◽  
Diabetes Remission ◽  
Cox Proportional Hazards ◽  
Proportional Hazards Models ◽  
Cox Proportional Hazards Models ◽  
Design And Methods ◽  
Time Varying Covariates

<b>Objective:</b> There are few studies testing the amount of weight loss necessary to achieve initial remission of type 2 diabetes (T2DM) following bariatric surgery and no published studies using weight loss to predict initial T2DM remission in sleeve gastrectomy (SG) patients. <p><b>Research Design and Methods:</b> Cox proportional hazards models examined the relationship between initial T2DM remission and percent total weight loss (%TWL) after bariatric surgery. Categories of %TWL were included in the model as time-varying covariates. </p> <p><b>Results:</b> Patients (N=5,928) were 73% female, 49.8<u>+</u>10.3 years old, had BMI of 43.8<u>+</u>6.92 kg/m<sup>2</sup>, and 57% had Roux-en-Y gastric bypass (RYGB). Over an average follow-up of 5.9 years, 71% of patients experienced initial remission of their T2DM (mean time to remission 1.0 year). Using 0-5% TWL as the reference group in Cox proportional hazards models, patients were more likely to remit with each 5% increase in TWL until 20% TWL (range from HR=1.97 to 2.92). When categories above >25% TWL were examined, all had a likelihood of initial remission similar to 20-25% TWL. Patients who achieved >20% TWL were more likely to achieve initial T2DM remission than patients with 0-5% TWL, even if they were using insulin at the time of surgery.</p> <p><b>Conclusions: </b>Weight loss after bariatric surgery is strongly associated with initial T2DM remission; however, above a threshold of 20% TWL, rates of initial T2DM remission did not increase substantially. Achieving this threshold is also associated with initial remission even in patients who traditionally experience lower rates of remission, such as patients taking insulin.</p>

scholarly journals Minimum Threshold of Bariatric Surgical Weight Loss for Initial Diabetes Remission

2021 ◽  
Author(s):  
Douglas Barthold ◽  
Elizabeth Brouwer ◽  
Lee J. Barton ◽  
David E. Arterburn ◽  
Anirban Basu ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Weight Loss ◽  
Proportional Hazards ◽  
Reference Group ◽  
Diabetes Remission ◽  
Cox Proportional Hazards ◽  
Proportional Hazards Models ◽  
Cox Proportional Hazards Models ◽  
Design And Methods ◽  
Time Varying Covariates

<b>Objective:</b> There are few studies testing the amount of weight loss necessary to achieve initial remission of type 2 diabetes (T2DM) following bariatric surgery and no published studies using weight loss to predict initial T2DM remission in sleeve gastrectomy (SG) patients. <p><b>Research Design and Methods:</b> Cox proportional hazards models examined the relationship between initial T2DM remission and percent total weight loss (%TWL) after bariatric surgery. Categories of %TWL were included in the model as time-varying covariates. </p> <p><b>Results:</b> Patients (N=5,928) were 73% female, 49.8<u>+</u>10.3 years old, had BMI of 43.8<u>+</u>6.92 kg/m<sup>2</sup>, and 57% had Roux-en-Y gastric bypass (RYGB). Over an average follow-up of 5.9 years, 71% of patients experienced initial remission of their T2DM (mean time to remission 1.0 year). Using 0-5% TWL as the reference group in Cox proportional hazards models, patients were more likely to remit with each 5% increase in TWL until 20% TWL (range from HR=1.97 to 2.92). When categories above >25% TWL were examined, all had a likelihood of initial remission similar to 20-25% TWL. Patients who achieved >20% TWL were more likely to achieve initial T2DM remission than patients with 0-5% TWL, even if they were using insulin at the time of surgery.</p> <p><b>Conclusions: </b>Weight loss after bariatric surgery is strongly associated with initial T2DM remission; however, above a threshold of 20% TWL, rates of initial T2DM remission did not increase substantially. Achieving this threshold is also associated with initial remission even in patients who traditionally experience lower rates of remission, such as patients taking insulin.</p>

465 Evaluating the Impact of Sleep Disordered Breathing on Adverse Cardiovascular Outcomes After Bariatric Surgery

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A183-A184
Author(s):  
Catherine Heinzinger ◽  
Pornprapa Chindamporn ◽  
James Bena ◽  
Lu Wang ◽  
Alex Milinovich ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Sleep Disordered Breathing ◽  
Proportional Hazards ◽  
Reference Group ◽  
Cleveland Clinic ◽  
Cox Proportional Hazards ◽  
Cardiovascular Outcomes ◽  
Proportional Hazards Models ◽  
Cox Proportional Hazards Models ◽  
Post Bariatric Surgery

Abstract Introduction Sleep disordered breathing (SDB), including obstructive sleep apnea (OSA) and obesity-associated sleep hypoventilation (OASH), has well-characterized adverse effects on the cardiovascular system and increases morbidity and mortality. Long-term impact on cardiovascular outcomes post-bariatric surgery, however, remains unclear. We hypothesize that patients with SDB have increased frequency of major adverse cardiovascular events (MACE) post-bariatric surgery than those without. Methods Patients undergoing polysomnography (PSG) prior to bariatric surgery at The Cleveland Clinic from 2011–2018 were retrospectively examined and followed up from date of last surgery to 2019, including the perioperative period. Primary predictors include moderate-severe OSA, i.e. apnea hypopnea index(AHI)&gt;15, and OASH, i.e. body mass index (BMI)≥30kg/m2 and either end-tidal CO2≥45mmHg or serum bicarbonate≥27mEq/L. MACE (coronary artery events, cerebrovascular events, heart failure or atrial fibrillation)-free probability was compared using hazard ratios estimated from Cox proportional hazards models on four groups: OASH with moderate-severe OSA (N=492), OASH-only (N=442), moderate-severe OSA-only (N=203), and a reference group without OASH or moderate-severe OSA (N=243). Multivariable Cox proportional hazards models adjusting for age, sex, BMI were fit on MACE survival. Analysis was performed based on an overall significance level of 0.05, using SAS software (version 9.4, Cary, NC). Results The sample comprised 1380 patients: age: 43.5±12 years, BMI: 49±9 kg/m2, 17.7% male, 63.7% White. Risk of MACE across the groups bordered significance (p=0.051). Compared to the reference group, the OASH with moderate-severe OSA group had higher risk of MACE (HR2.53, 95%CI:1.07–6.00,p=0.035). Patients with moderate-severe OSA had higher risk of MACE than those with AHI&lt;15 (HR1.94, 95%CI:1.20–3.13,p=0.007). Patients with severe OSA had higher risk of MACE than those AHI&lt;30 (HR2.01, 95%CI:1.28–3.14,p=0.002). For every 5-unit AHI increase, risk of MACE increased by 6% (HR1.056, 95%CI:1.029–1.084,p&lt;0.001) with slight reduction in point estimates in adjusted models. Conclusion Preliminary data from this largest-to-date sample of systematically phenotyped patients with SDB undergoing bariatric surgery show significant differences in risk of MACE and MACE-free survival mitigated after consideration of obesity. Further investigation to elucidate effect modification by obesity and metabolic factors is needed. Support (if any) Cleveland Clinic Transformative Resource Neuroscience Award

scholarly journals Generating Survival Times Using Cox Proportional Hazards Models with Cyclic and Piecewise Time-Varying Covariates

2020 ◽  
Vol 12 (3) ◽  
pp. 324-339 ◽  
Author(s):  
Yunda Huang ◽  
Yuanyuan Zhang ◽  
Zong Zhang ◽  
Peter B. Gilbert
Keyword(s):  
Survival Data ◽  
Dose Regimen ◽  
Hazard Function ◽  
Proportional Hazards ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
Time Varying ◽  
Proportional Hazards Models ◽  
Cox Proportional Hazards Models ◽  
Time Varying Covariates

Abstract Time-to-event outcomes with cyclic time-varying covariates are frequently encountered in biomedical studies that involve multiple or repeated administrations of an intervention. In this paper, we propose approaches to generating event times for Cox proportional hazards models with both time-invariant covariates and a continuous cyclic and piecewise time-varying covariate. Values of the latter covariate change over time through cycles of interventions and its relationship with hazard differs before and after a threshold within each cycle. The simulations of data are based on inverting the cumulative hazard function and a log link function for relating the hazard function to the covariates. We consider closed-form derivations with the baseline hazard following the exponential, Weibull, or Gompertz distribution. We propose two simulation approaches: one based on simulating survival data under a single-dose regimen first before data are aggregated over multiple-dosing cycles and another based on simulating survival data directly under a multiple-dose regimen. We consider both fixed intervals and varying intervals of the drug administration schedule. The method’s validity is assessed in simulation experiments. The results indicate that the proposed procedures perform well in generating data that conform to their cyclic nature and assumptions of the Cox proportional hazards model.

scholarly journals Changes in Metabolic Syndrome Status and Breast Cancer Risk: A Nationwide Cohort Study

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1177
Author(s):  
In Young Choi ◽  
Sohyun Chun ◽  
Dong Wook Shin ◽  
Kyungdo Han ◽  
Keun Hye Jeon ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metabolic Syndrome ◽  
Proportional Hazards ◽  
Screening Program ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Models ◽  
Hazard Ratios ◽  
Increased Risk ◽  
Health Screening Program ◽  
Design And Methods

Objective: To our knowledge, no studies have yet looked at how the risk of developing breast cancer (BC) varies with changes in metabolic syndrome (MetS) status. This study aimed to investigate the association between changes in MetS and subsequent BC occurrence. Research Design and Methods: We enrolled 930,055 postmenopausal women aged 40–74 years who participated in a biennial National Health Screening Program in 2009–2010 and 2011–2012. Participants were categorized into four groups according to change in MetS status during the two-year interval screening: sustained non-MetS, transition to MetS, transition to non-MetS, and sustained MetS. We calculated multivariable-adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for BC incidence using the Cox proportional hazards models. Results: At baseline, MetS was associated with a significantly increased risk of BC (aHR 1.11, 95% CI 1.06–1.17) and so were all of its components. The risk of BC increased as the number of the components increased (aHR 1.46, 95% CI 1.26–1.61 for women with all five components). Compared to the sustained non-MetS group, the aHR (95% CI) for BC was 1.11 (1.04–1.19) in the transition to MetS group, 1.05 (0.96–1.14) in the transition to non-MetS group, and 1.18 (1.12–1.25) in the sustained MetS group. Conclusions: Significantly increased BC risk was observed in the sustained MetS and transition to MetS groups. These findings are clinically meaningful in that efforts to recover from MetS may lead to reduced risk of BC.

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