The true obesity paradox: obese and malnourished?

Baseline 25(OH)D level is a prognostic indicator for bariatric surgery readmission: a matched retrospective cohort study

Introduction

Managing postsurgical complications is crucial in optimizing the outcomes of bariatric surgery, for which preoperative nutritional assessment is essential. In this study, we aimed to evaluate and validate the efficacy of vitamin D levels as an immunonutritional biomarker for bariatric surgery prognosis.

Methods

This matched retrospective cohort study included adult patients who underwent bariatric surgery at a tertiary medical center in China between July 2021 and June 2022. Patients with insufficient and sufficient 25(OH)D (< 30 ng/mL) were matched in a 1:1 ratio. Follow-up records of readmission at 3 months, 6 months, and 1 year were obtained to identify prognostic indicators.

Results

A matched cohort of 452 patients with a mean age of 37.14 ± 9.25 years and involving 69.47% females was enrolled. Among them, 94.25 and 5.75% underwent sleeve gastrectomy and gastric bypass, respectively. Overall, 25 patients (5.54%) were readmitted during the 1-year follow-up. The prognostic nutritional index and controlling nutritional status scores calculated from inflammatory factors did not efficiently detect malnourishment. A low 25(OH)D level (3.58 [95% CI, 1.16-11.03]) and surgery season in summer or autumn (2.68 [95% CI, 1.05-6.83]) increased the risk of 1-year readmission in both the training and validation cohorts. The area under the receiver operating characteristic curve was 0.747 (95% CI, 0.640-0.855), with a positive clinical benefit in the decision curve analyses. The relationship between 25(OH)D and 6-month readmission was U-shaped.

Conclusion

Serum 25(OH)D levels have prognostic significance in bariatric surgery readmission. Hence, preferable 25(OH)D levels are recommended for patients undergoing bariatric surgery.

Nutrition status, obesity and outcomes in patients with atrial fibrillation

INTRODUCTION AND OBJECTIVES

A paradoxical protective effect of obesity has been previously reported in patients with atrial fibrillation (AF). The aim of this study was to determine the impact of nutritional status and body mass index (BMI) on the prognosis of AF patients.

METHODS

We conducted a retrospective population-based cohort study of patients with AF from 2014 to 2017 from a single health area in Spain. The CONUT score was used to assess nutritional status. Cox regression models were used to estimate the association of BMI and CONUT score with mortality. The association with embolism and bleeding was assessed by a competing risk analysis.

RESULTS

Among 14 849 AF patients, overweight and obesity were observed in 42.6% and 46.0%, respectively, while malnutrition was observed in 34.3%. During a mean follow-up of 4.4 years, 3335 patients died, 984 patients had a stroke or systemic embolism, and 1317 had a major bleeding event. On univariate analysis, BMI was inversely associated with mortality, embolism, and bleeding; however, this association was lost after adjustment by age, sex, comorbidities, and CONUT score (HR for composite endpoint, 0.98; 95%CI, 0.95-1.01; P=.719). Neither obesity nor overweight were predictors of mortality, embolism, and bleeding events. In contrast, nutritional status-assessed by the CONUT score-was associated with mortality, embolism and bleeding after multivariate analysis (HR for composite endpoint, 1.15; 95%CI, 1.14-1.17; P<.001).

CONCLUSIONS

BMI was not an independent predictor of events in patients with AF in contrast to nutritional status, which showed a strong association with mortality, embolism, and bleeding. The study was registered at ClinicalTrials.gov (Identifier: NCT04364516).

Micronutrient status of individuals with overweight and obesity following 3 months' supplementation with PolyGlycopleX (PGX®) or psyllium: a randomized controlled trial

Background

Safe and effective weight control strategies are needed to curtail the current obesity epidemic worldwide. Increasing dietary fibre has shown positive results with weight loss as well as in the reduction of metabolic syndrome risk factors. However, fibre can act as an inhibitor to the bioavailability of micronutrients in the gastrointestinal tract. While there is a substantial amount of scientific research into psyllium fibre, PolyGlycopleX (PGX®) is a novel fibre and as yet the effects of PGX® on micronutrient status is not well researched.

Aim

To determine whether 3-months’ supplementation with 15 g of psyllium or PGX® fibre daily affects micronutrient status of overweight and obese adults.

Methods

Overweight and obese individuals with a BMI between 25–40 kg/m² and aged between 18 and 65 years, but otherwise healthy, were instructed to consume a 5 g sachet of psyllium, PGX® fibre or a rice flour placebo three times a day for 52 weeks as part of a larger long-term study. Blood sample data for the first 3 months were analysed for associations between serum micronutrient levels and psyllium fibre and/or PGX® supplements.

Results

No significant differences between fibre supplement groups and micronutrient status were found after 3 months at p > 0.05. Dietary intake of vitamin C was significantly lower for PGX® at 3 months compared to baseline and compared to control (p < 0.05). Folate was significantly lower in the control group after 3 months (p < 0.05). In the psyllium group, folate, sodium, zinc and magnesium intake decreased after 3 months (p < 0.05). A limitation of dietary intake data (tertiary measure) is the potential for inaccurate self-reporting, although reduced nutrient intake could be due to the satiating effect of dietary fibre.

Conclusions

There were no significant between group differences in serum micronutrient concentrations after a 3-month psyllium fibre or PGX® supplementation intervention of 15 g per day. Fibre supplementation is unlikely to compromise the nutritional status of overweight and obese individuals in the short term. Further research is recommended to monitor micronutrient status over a longer period or with a higher fibre dosage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40795-022-00534-7.

[Septic revision arthroplasty: how to confirm diagnosis, plan surgery and manage follow-up treatment]

BACKGROUND

Septic revision arthroplasty represents an interdisciplinary challenge in terms of diagnosis as well as surgical and follow-up treatment.

DIAGNOSIS

The implementation of a standardized diagnostic algorithm including anamnesis, clinic, imaging, blood sampling and joint aspiration is essential. Depending on the duration of the symptoms acute (< 3 weeks) and chronic (> 3 weeks) infections are distinguished.

THERAPY

While acute infections show an immature biofilm and can usually be addressed surgically via debridement and changing the mobile parts, chronic infections almost always require a complete change of the implant. This can be done in one or two stages, depending on the general condition of the patient, the pathogen, its resistances as well as the wound conditions. The surgical revision is always followed by a resistance-based antibiotic treatment.

Visceral Adiposity in Relation to Body Adiposity and Nutritional Status in Elderly Patients with Stable Coronary Artery Disease

Introduction: The accumulation of visceral abdominal tissue (VAT) seems to be a hallmark feature of abdominal obesity and substantially contributes to metabolic abnormalities. There are numerous factors that make the body-mass index (BMI) a suboptimal measure of adiposity. The visceral adiposity index (VAI) may be considered a simple surrogate marker of visceral adipose tissue dysfunction. However, the evidence comparing general to visceral adiposity in CAD is scarce. Therefore, we have set out to investigate visceral adiposity in relation to general adiposity in patients with stable CAD. Material and methods: A total of 204 patients with stable CAD hospitalized in the Department of Medicine and the Department of Geriatrics entered the study. Based on the VAI-defined adipose tissue dysfunction (ATD) types, the study population (N = 204) was divided into four groups: (1) no ATD (N = 66), (2) mild ATD (N = 50), (3) moderate ATD (N = 48), and (4) severe ATD (N = 40). Nutritional status was assessed using the Controlling Nutritional Status (CONUT) score. Results: Patients with moderate and severe ATD were the youngest (median 67 years), yet their metabolic age was the oldest (median 80 and 84 years, respectively). CONUT scores were similar across all four study groups. The VAI had only a modest positive correlation with BMI (r = 0.59 p < 0.01) and body adiposity index (BAI) (r = 0.40 p < 0.01). There was no correlation between VAI and CONUT scores. There was high variability in the distribution of BMI-defined weight categories across all four types of ATD. A total of 75% of patients with normal nutritional status had some form of ATD, and one-third of patients with moderate or severe malnutrition did not have any ATD (p = 0.008). In contrast, 55-60% of patients with mild, moderate, or severe ATD had normal nutritional status (p = 0.008). ROC analysis demonstrated that BMI and BAI have poor predictive value in determining no ATD. Both BMI (AUC 0.78 p < 0.0001) and BAI (AUC 0.66 p = 0.003) had strong predictive value for determining severe ATD (the difference between AUC 0.12 being p = 0.0002). However, BMI predicted mild ATD and severe ATD better than BAI. Conclusions: ATD and malnutrition were common in patients with CAD. Notably, this study has shown a high rate of misclassification of visceral ATD via BMI and BAI. In addition, we demonstrated that the majority of patients with normal nutritional status had some form of ATD and as much as one-third of patients with moderate or severe malnutrition did not have any ATD. These findings have important clinical ramifications for everyday practice regarding the line between health and disease in the context of malnutrition in terms of body composition and visceral ATD, which are significant for developing an accurate definition of the standards for the intensity of clinical interventions.

Obesity and malnutrition in critically ill patients with acute myeloid leukemia: Prevalence and impact on mortality

OBJECTIVES

Obese patients have an increased risk of developing acute myeloid leukemia (AML), which in turn predisposes to malnutrition. Obesity has been associated with improved survival in critically ill patients (obesity paradox), but this effect seems to disappear when adjusting for malnutrition. How obesity and malnutrition interplay to affect mortality in critically ill patients with AML has not been addressed and was the objective of this study.

METHODS

This was a retrospective chart review of adult patients with AML who were admitted to the medical intensive care unit and had a nutrition consultation between 2011 and 2018. Demographic characteristics, comorbidities, severity scores, and laboratory parameters, as well as data on vital organ support, hospital mortality, and long-term survival were collected. Obesity was defined by a body mass index of ≥30 kg/m² and malnutrition per the American Society for Parenteral and Enteral Nutrition criteria. Patients were compared based on nutrition and weight status, and hospital and long-term mortality were analyzed with logistic regression and Kaplan-Meier curves.

RESULTS

We included 145 patients (57% obese, 30% malnourished) in the study. As time from AML diagnosis elapsed, obesity was less frequent and malnutrition more prevalent, with 25% of obese patients also presenting with malnutrition. Hospital mortality was 40% and associated with malnutrition in nonobese patients (odds ratio: 5.1; 95% confidence interval, 1.3-21.8; P = 0.02) and sequential organ failure assessment severity score (odds ratio: 1.5; 95% confidence interval, 1.3-1.7; P < 0.0001). Sensitivity analyses confirmed the association between malnutrition, but not obesity, and hospital mortality. Obese malnourished patients had lower long-term survival, but this was not significant (P = 0.25).

CONCLUSIONS

Critically ill patients with AML have a high prevalence of malnutrition and obesity, which are sometimes associated. Malnutrition, but not obesity, was associated with hospital mortality.

Helping Patients Eat Better During and Beyond Cancer Treatment: Continued Nutrition Management Throughout Care to Address Diet, Malnutrition, and Obesity in Cancer

Cancer patients and survivors are at risk of poor clinical outcomes due to poor nutritional intake following cancer diagnosis. During cancer treatment, treatment toxicities can affect eating patterns and can lead to malnutrition resulting in loss of lean body mass and excessive weight loss. Following treatment and throughout survivorship, patients are at risk of not meeting national nutrition guidelines for cancer survivors, which can affect recurrence and survival. Obesity, which is highly prevalent in cancer patients and survivors, can affect clinical outcomes during treatment by masking malnutrition and is also a risk factor for cancer recurrence and poorer survival in some cancers. Appropriate and effective nutritional education and guidance by trained clinicians are needed throughout the cancer continuum. This article presents an overview of recommendations and guidelines for nutrition and weight management and provides recent examples of behavioral theory-based targeted lifestyle interventions designed to increase adherence to recommendation by cancer patients and survivors.

Serum albumin or body mass index: Which prognostic factor for survival in patients with acute myeloblastic leukaemia?

Obesity has been associated with an increased risk of developing acute myeloblastic leukaemia (AML). The outcome of AML patients could thus be dependent on their nutritional status that can be evaluated by the simple measurement of serum albumin (SA) and body mass index (BMI). These two parameters could have a value as prognostic factors to guide patients' management. We evaluated the association between SA levels, BMI, and survival, evaluated as overall survival (OS) and event-free survival. Furthermore, we investigated the association between BMI, SA, and other prognostic factors of interest in AML. This retrospective single-center study included 159 patients diagnosed with AML at Nancy Hospital between 2005 and 2013, treated with aracytine and anthracycline. Forty-four percent of patients presented with normal weight while 56% were obese/overweight. Serum albumin levels were <30 g/L for 49 patients, and ≥30 g/L for 110. Thirty-four patients with low SA levels were also obese. Favourable OS was associated with SA levels ≥30 g/L (HR = 0.467; 95% CI 0.230-0.946; P = .034) but was not impacted by the BMI. Serum albumin levels appear to be an independent prognostic factor in AML and a better parameter than BMI for evaluating the nutritional status of patients at diagnosis.

Outside the Bone: What Is Happening Systemically to Influence Fracture Healing?

This article summarizes presentations of a symposium on bone health-related hot topics of the 2016 Basic Science Focus Forum. Taken together, these topics emphasize the critical importance of bone health in fracture management, the systemic factors that influence fracture healing, and the need to focus on issues other than simply the technical aspects of fracture repair.

Feeding the critically ill obese patient: a systematic review protocol

REVIEW QUESTION/OBJECTIVE

The objective of this review is to identify effective enteral nutritional regimens targeting protein and calorie delivery for the critically ill obese patient on morbidity and mortality.More specifically, the review question is:In the critically ill obese patient, what is the optimal enteral protein and calorie target that improves mortality and morbidity?

BACKGROUND

The World Health Organization (WHO) defines obesity as abnormal or excessive fat accumulation that may impair health, or, empirically, as a body mass index (BMI) ≥ 30 kg/m. Twenty-eight percent of the Australian population is obese with the prevalence rising to 44% in rural areas, and there is evidence that rates of obesity are increasing. The prevalence of obese patients in intensive care largely mirrors that of the general population. There is concern, however, that this may also be rising. A recently published multi-center nutritional study of critically ill patients reported a mean BMI of 29 in their sample, suggesting that just under 50% of their intensive care population is obese. It is inevitable, therefore, that the intensivist will care for the critically ill obese patient.Managing the critically ill obese patient is challenging, not least due to the co-morbid diseases frequently associated with obesity, including diabetes mellitus, cardiovascular disease, dyslipidaemia, sleep disordered breathing and respiratory insufficiency, hepatic steatohepatitis, chronic kidney disease and hypertension. There is also evidence that metabolic processes differ in the obese patient, particularly those with underlying insulin resistance, itself a marker of the metabolic syndrome, which may predispose to futile cycling, altered fuel utilization and protein catabolism. These issues are compounded by altered drug pharmacokinetics, and the additional logistical issues associated with prophylactic, therapeutic and diagnostic interventions.It is entirely plausible that the altered metabolic processes observed in the obese intensify and compound the metabolic changes that occur during critical illness. The early phases of critical illness are characterized by an increase in energy expenditure, resulting in a catabolic state driven by the stress response. Activation of the stress response involves up-regulation of the sympathetic nervous system and the release of pituitary hormones resulting in altered cortisol metabolism and elevated levels of endogenous catecholamines. These produce a range of metabolic disturbances including stress hyperglycemia, arising from both peripheral resistance to the effects of anabolic factors (predominantly insulin) and increased hepatic gluconeogenesis. Proteolysis is accelerated, releasing amino acids that are thought to be important in supporting tissue repair, immune defense and the synthesis of acute phase reactants. There is also altered mobilization of fuel stores, futile cycling, and evidence of altered lipoprotein metabolism. In the short term this is likely to be an adaptive response, but with time and ongoing inflammation this becomes maladaptive with a concomitant risk of protein-calorie malnutrition, immunosuppression and wasting of functional muscle tissue resulting from protein catabolism, and this is further compounded by disuse atrophy. Muscle atrophy and intensive care unit (ICU) acquired weakness is complex and poorly understood, but it is postulated that the provision of calories and sufficient protein to avoid a negative nitrogen balance mitigates this process. Avoiding lean muscle mass loss in the obese intuitively has substantial implications, given the larger mass that is required to be mobilized during their rehabilitation phase.There is, in addition, evolving evidence that hormones derived from both the gut and adipose tissue are also involved in the response to stress and critical illness, and that adipose tissue in particular is not a benign tissue bed, but rather should be considered an endocrine organ. Some of these hormones are thought to be pro-inflammatory and some anti-inflammatory; however both the net result and clinical significance of these are yet to be fully elucidated.The provision of adequate nutrition has become an integral component of supportive ICU care, but is complex. There is ongoing debate within critical care literature regarding the optimal route of delivery, the target dose, and the macronutrient components (proportion of protein and non-protein calories) of nutritional support. A number of studies have associated caloric deficit with morbidity and mortality, with the resultant assumption that prescribing sufficient calories to match energy expenditure will reduce morbidity and mortality, although the evidence base underpinning this assumption is limited to observational studies and small, randomized trials.There is research available that suggests hyper-caloric feeding or hyper-alimentation, particularly of carbohydrates, may result in increased morbidity including hyperglycemia, liver steatosis, respiratory insufficiency with prolonged duration of mechanical ventilation, re-feeding syndrome and immune suppression. But the results from studies of hypo-caloric and eucaloric feeding regimens in critically ill patients are conflicting, independent of the added metabolic complexities observed in the critically ill obese patient.Notwithstanding the debate regarding the dose and components of nutritional therapy, there is consensus that nutrition should be provided, preferably via the enteral route, and preferably initiated early in the ICU admission. The enteral route is preferred for a variety of reasons, not the least of which is cost. In addition there is evidence to suggest the enteral route is associated with the maintenance of gut integrity, a reduction in bacterial translocation and infection rates, a reduction in the incidence of stress ulceration, attenuation of oxidative stress, release of incretins and other entero-hormones, and modulation of systemic immune responses. Yet there is evidence that the initiation of enteral nutritional support for the obese critically ill patient is delayed, and that when delivered is at sub-optimal levels. The reasons for this remain obscure, but may be associated with the false assumption that every obese patient has nutritional reserves due to their adipose tissues, and can therefore withstand longer periods with no, or reduced nutritional support. In fact obesity does not necessarily protect from malnutrition, particularly protein and micronutrient malnutrition. It has been suggested by some authors that the malnutrition status of critically ill patients is a stronger predictor of mortality than BMI, and that once malnutrition status is controlled for, the apparent protective effects of obesity observed in several epidemiological studies dissipate. This would be consistent with the large body of evidence that associates malnutrition (BMI < 20 kg/m) with increased mortality, and has led some authors to postulate that the weight-mortality relationship is U-shaped. This has proven difficult to demonstrate, however, due to recognized confounding influences such as chronic co-morbidities, baseline nutritional status and the nature of the presenting critical illness.This has led to interest in nutritional regimens targeting alternative calorie and protein goals to protect the obese critically ill patient from complications arising from critical illness, and particularly protein catabolism. However, of the three major nutritional organizations, the American Society of Parenteral and Enteral Nutrition (ASPEN) is the only professional organization to make specific recommendations about providing enteral nutritional support to the critically ill obese patient, recommending a regimen targeting a hypo-caloric, high-protein goal. It is thought that this regimen, in which 60-70% of caloric requirements are provided promotes steady weight loss, while providing sufficient protein to achieve a neutral, or slightly positive, nitrogen balance, mitigating lean muscle mass loss, and allowing for wound healing. Targeting weight loss is proposed to improve insulin sensitivity, improve nursing care and reduce the risk of co-morbidities, although how this occurs and whether it can occur over the relatively short time frame of an intensive care admission (days to weeks) remains unclear. Despite these recommendations observational data of international nutritional practice suggest that ICU patients are fed uniformly low levels of calories and protein across BMI groups.Supporting the critically ill obese patient will become an increasingly important skill in the intensivist's armamentarium, and enteral nutritional therapy forms a cornerstone of this support. Yet, neither the optimal total caloric goal nor the macronutrient components of a feeding regimen for the critically ill obese patient is evident. Although the suggestion that altering the macronutrient goals for this vulnerable group of patients appears to have a sound physiological basis, the level of evidence supporting this remains unclear, and there are no systematic reviews on this topic. The aim of this systematic review is to evaluate existing literature to determine the best available evidence describing a nutritional strategy that targets energy and protein delivery to reduce morbidity and mortality for the obese patient who is critically ill.

OBESITY AND CRITICAL ILLNESS: INSIGHTS FROM ANIMAL MODELS

Critical illness is a major cause of morbidity and mortality around the world. While obesity is often detrimental in the context of trauma, it is paradoxically associated with improved outcomes in some septic patients. The reasons for these disparate outcomes are not well understood. A number of animal models have been used to study the obese response to various forms of critical illness. Just as there have been many animal models that have attempted to mimic clinical conditions, there are many clinical scenarios that can occur in the highly heterogeneous critically ill patient population that occupies hospitals and intensive care units. This poses a formidable challenge for clinicians and researchers attempting to understand the mechanisms of disease and develop appropriate therapies and treatment algorithms for specific subsets of patients, including the obese. The development of new, and the modification of existing animal models, is important in order to bring effective treatments to a wide range of patients. Not only do experimental variables need to be matched as closely as possible to clinical scenarios, but animal models with pre-existing comorbid conditions need to be studied. This review briefly summarizes animal models of hemorrhage, blunt trauma, traumatic brain injury, and sepsis. It also discusses what has been learned through the use of obese models to study the pathophysiology of critical illness in light of what has been demonstrated in the clinical literature.

Risk factors for and prediction of mortality in critically ill medical-surgical patients receiving heparin thromboprophylaxis

Background

Previous studies have suggested that prediction models for mortality should be adjusted for additional risk factors beyond the Acute Physiology and Chronic Health Evaluation (APACHE) score. Our objective was to identify risk factors independent of APACHE II score and construct a prediction model to improve the predictive accuracy for hospital and intensive care unit (ICU) mortality.

Methods

We used data from a multicenter randomized controlled trial (PROTECT, Prophylaxis for Thromboembolism in Critical Care Trial) to build a new prediction model for hospital and ICU mortality. Our primary outcome was all-cause 60-day hospital mortality, and the secondary outcome was all-cause 60-day ICU mortality.

Results

We included 3746 critically ill non-trauma medical–surgical patients receiving heparin thromboprophylaxis (43.3 % females) in this study. The new model predicting 60-day hospital mortality incorporated APACHE II score (main effect: hazard ratio (HR) = 0.97 for per-point increase), body mass index (BMI) (main effect: HR = 0.92 for per-point increase), medical admission versus surgical (HR = 1.67), use of inotropes or vasopressors (HR = 1.34), acetylsalicylic acid or clopidogrel (HR = 1.27) and the interaction term between APACHE II score and BMI (HR = 1.002 for per-point increase). This model had a good fit to the data and was well calibrated and internally validated. However, the discriminative ability of the prediction model was unsatisfactory (C index < 0.65). Sensitivity analyses supported the robustness of these findings. Similar results were observed in the new prediction model for 60-day ICU mortality which included APACHE II score, BMI, medical admission and invasive mechanical ventilation.

Conclusion

Compared with the APACHE II score alone, the new prediction model increases data collection, is more complex but does not substantially improve discriminative ability.

Trial registration: ClinicalTrials.gov Identifier: NCT00182143