Impact of Obesity and Visceral Fat on Mortality in Hematopoietic Stem Cell Transplantation

Health professional attitudes and perceptions of prehabilitation and nutrition before haematopoietic cell transplantation

BACKGROUND

Nutritional prehabilitation may improve haematopoietic cell transplantation (HCT) outcomes, although little evidence exists. The present study aimed to understand healthcare professional (HCP) perceptions of prehabilitation and nutritional care pre-HCT in UK centres.

METHODS

An anonymous online survey (developed and refined via content experts and piloting) was administered via email to multidisciplinary HCPs in 39 UK adult centres, between July 2021 and June 2022. Data are presented as proportions of responses. Routine provision denotes that care was provided >70% of time.

RESULTS

Seventy-seven percent (n = 66) of HCPs, representing 61.5% (n = 24) of UK adult HCT centres, responded. All HCPs supported prehabilitation, proposing feasible implementation between induction chemotherapy (60.4%; n = 40) and first HCT clinic (83.3%; n = 55). Only 12.5% (n = 3) of centres had a dedicated prehabilitation service. Nutrition (87.9%; n = 58), emotional wellbeing (92.4%; n = 61) and exercise (81.8%; n = 54) were considered very important constituents. HCPs within half of the HCT centres (n = 12 centres) reported routine use of nutrition screening pre-HCT with a validated tool; 66.7% of HCPs (n = 36) reported using the malnutrition universal screening tool (MUST). Sixty-two percent (n = 41) of HCPs reported those at risk, received nutritional assessments, predominantly by dietitians (91.6%; n = 22) using the dietetic care process (58.3%; n = 14). Body mass index (BMI) was the most frequently reported body composition measure used by HCPs (70.2%, n = 33). Of 59 respondents, non-dietitians most routinely provided dietary advice pre-HCT (82.4%; n = 28 vs. 68%; n = 17, p = 0.2); including high-energy/protein/fat and neutropenic diet advice. Prophylactic enteral feeding pre-HCT was rare, indicated by low BMI and significant unintentional weight loss. Just under half (n = 25 of 59, 42.4%) HCPs reported exercise advice was given routinely pre-HCT.

CONCLUSIONS

Nutrition and prehabilitation pre-HCT are considered important and deliverable by HCPs, but current provision in UK centres is limited and inconsistent.

Nutritional status and body mass index before hematopoietic stem cell transplantation (HSCT) and associated outcomes: a rapid review

PURPOSE

Hematopoietic stem cell transplantation (HSCT) recipients experience several post-HSCT complications affecting nutritional status, body mass index (BMI), and mortality that can potentially be mitigated by nutritional management. This rapid review examines the relationship between pre-HSCT nutritional status and BMI and post-HSCT survival.

METHODS

Articles were identified from PubMed, Scopus, and Embase. Two researchers independently completed the title, abstract, and full-text review. Inclusion criteria included the following: (1) randomized clinical trials or observational studies; (2) human subjects diagnosed with cancer and undergoing HSCT; (3) reported pre-HSCT nutritional status (e.g., diet recall, nutritional survey, dietitian session) or BMI; and (4) reported treatment related mortality and/or survival.

RESULTS

The initial search found 3036 articles, 28 were included in full-text review, and 18 met inclusion criteria. Articles had quasi-experimental (n = 2) and observational (n = 16) study designs. Of the studies, n = 5 reported nutritional intake decreased post-HSCT, and n = 2 reported nutrition intervention (i.e., controlled feeding) post-HSCT improved survival. Four studies reported having a BMI classified as underweight improved survival, while n = 5 reported having a BMI classified as overweight or obese improved survival.

CONCLUSION

Current research exploring the relationship between nutritional status and BMI with HSCT survival is mixed. Further research is needed to determine how nutritional status and BMI are associated withsurvival post-HSCT to inform future intervention work.

A predictive model combining clinical characteristics and nutritional risk factors for overall survival after umbilical cord blood transplantation

BACKGROUND

Umbilical cord blood transplantation (UCBT) is a curable therapy for hematological disease; however, the impact of nutritional status on UCBT outcomes remains controversial. To evaluate the joint effect of clinical characteristics and nutritional status on the prognosis of patients who underwent UCBT, we screened various factors to establish a predictive model of overall survival (OS) after UCBT.

METHODS

We performed an integrated clinical characteristic and nutritional risk factor analysis and established a predictive model that could be used to identify UCBT recipients with poor OS. Internal validation was performed by using the bootstrap method with 500 repetitions.

RESULTS

Four factors, including disease status, conditioning regimen, calf skinfold thickness and albumin level, were identified and used to develop a risk score for OS, which showed a positive predictive value of 84.0%. A high-risk score (≥ 2.225) was associated with inferior 3-year OS post-UCBT [67.5% (95% CI 51.1-79.4%), P = 0.001]. Then, we built a nomogram based on the four factors that showed good discrimination with a C-index of 0.833 (95% CI 0.743-0.922). The optimism-corrected C-index value of the bootstrapping was 0.804. Multivariate analysis suggested that a high calf skinfold thickness (≥ 20.5 mm) and a low albumin level (< 33.6 g/L) conferred poor disease-free survival (DFS).

CONCLUSION

The predictive model combining clinical and nutritional factors could be used to predict OS in UCBT recipients, thereby promoting preemptive treatment.

Multifaceted effects of obesity on cancer immunotherapies: Bridging preclinical models and clinical data

Obesity, defined by excessive body fat, is a highly complex condition affecting numerous physiological processes, such as metabolism, proliferation, and cellular homeostasis. These multifaceted effects impact cells and tissues throughout the host, including immune cells as well as cancer biology. Because of the multifaceted nature of obesity, common parameters used to define it (such as body mass index in humans) can be problematic, and more nuanced methods are needed to characterize the pleiotropic metabolic effects of obesity. Obesity is well-accepted as an overall negative prognostic factor for cancer incidence, progression, and outcome. This is in part due to the meta-inflammatory and immunosuppressive effects of obesity. Immunotherapy is increasingly used in cancer therapy, and there are many different types of immunotherapy approaches. The effects of obesity on immunotherapy have only recently been studied with the demonstration of an "obesity paradox", in which some immune therapies have been demonstrated to result in greater efficacy in obese subjects despite the direct adverse effects of obesity and excess body fat acting on the cancer itself. The multifactorial characteristics that influence the effects of obesity (age, sex, lean muscle mass, underlying metabolic conditions and drugs) further confound interpretation of clinical data and necessitate the use of more relevant preclinical models mirroring these variables in the human scenario. Such models will allow for more nuanced mechanistic assessment of how obesity can impact, both positively and negatively, cancer biology, host metabolism, immune regulation, and how these intersecting processes impact the delivery and outcome of cancer immunotherapy.

The role of cognitive function in the relationship between surrogate markers of visceral fat and depressive symptoms in general middle-aged and elderly population: A nationwide population-based study

BACKGROUND

The relationship between obesity and depressive symptoms is well documented, but not visceral fat, especially among Chinese adults are scarce. We aimed to investigate the association between visceral fat and depressive symptoms and the mediation of cognitive function.

METHODS

A total of 19,919 and 5555 participants from the China Health and Retirement Longitudinal Study were enrolled in the cross-sectional and follow-up analyses. Depressive symptoms were measured by the Center of Epidemiological studies depression scale (CES-D). Visceral fat measured by the waist circumference triglyceride (WT) index [calculated as waist circumference (cm)* triglyceride (mmol/L)]. The relationship between the WT index and depressive symptoms was analyzed by binary logistics and Poisson regression. The mediated role of cognitive ability was examined by intermediary analysis.

RESULTS

In the cross-sectional study, higher visceral fat was associated with a lower risk of depressive symptoms. But in the follow-up study, individuals in quintile 2 to quintile 4 of the WT index have a reduced risk of depressive symptoms after four years. Compared with the lower index, quintile 2 of the WT index protected from difficulty concentrating (RR [95%CI]: 0.90 [0.82,0.98], p = 0.023), feeling scared (RR [95%CI]: 0.86 [0.73,0.98], p = 0.030) and feeling that life could not go on (RR [95%CI]: 0.85 [0.74,0.98], p = 0.023). Moreover, cognitive ability explained 11.52 % of the association between visceral fat and depressive symptoms.

CONCLUSIONS

Our findings show that moderate visceral fat was associated with a lower risk of depressive symptoms in middle-aged and older Chinese, partly mediated by cognitive function.

Adapting the HCT-CI Definitions for Children, Adolescents, and Young Adults with Hematologic Malignancies Undergoing Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation is a curative procedure for hematologic malignancies but is associated with a significant risk of non-relapse mortality (NRM). The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) is a prognostic tool that discriminates this risk in all age groups. A recent survey of transplant physicians demonstrated that 79% of pediatric providers used the HCT-CI infrequently, and most reported concerns about its applicability in the younger population. We conducted a retrospective study using the Center for International Blood and Marrow Transplant Research database to examine the impact of expanded HCT-CI definitions on NRM in pediatric and young adult patients with hematologic malignancies. We included 5790 patients <40 years old receiving allogeneic transplants between 2008 and 2017 to examine broader definitions of comorbidities in the HCT-CI, including history of mechanical ventilation and fungal infection, estimated glomerular filtration rate, and body mass index (BMI) percentiles. Multivariable Fine-Gray models were created to determine the effect of each HCT-CI defining comorbidity and its modification on NRM and were used to develop 2 novel risk scores. We next developed the expanded HCT-CI for children and young adults (youth with malignancies; expanded ymHCT-CI), where 23% patients had an increased comorbidity score, compared to the HCT-CI. Comorbidities with hazard ratio < 1.2 were then removed to create the simplified HCT-CI for children and young adults (youth with malignancies; simplified ymHCT-CI), which demonstrated higher scores corresponded to a greater risk of NRM (P < .001). These novel comorbidity indexes with broader definitions are more relevant to pediatric and young adult patients, and prospective studies are needed to validate these in the younger patient population. It remains to be seen whether the development of these pediatric-specific and practical risk indexes increases their use by the pediatric transplant community.

Body Composition Impacts Hematopoietic Stem Cell Transplant Outcomes in Both Autologous and Allogeneic Transplants: A Systematic Review

According to World Health Organization, over 50,000 hematopoietic stem cell transplants (HSCTs) are performed annually worldwide. Though HSCT can extend life-expectancy and improve disease-related health burdens, it is not without risks. Post-transplant overall survival is improving; therefore, it is imperative that factors contributing to or impeding further improvements are well understood. The purpose of this systematic review is to explore current data on body composition (specifically weight loss, BMI, obesity and sarcopenia) and the relation to HSCT outcomes. A literature search was conducted via PubMed and Web of Science databases. Key words included "body composition," "sarcopenia," "hematopoietic stem cell transplant," "malnutrition," "body mass index," and "obesity." Results indicated that 16 out of 18 analyzed studies found a statistically significant relationship between body composition, in particular higher BMI and weight loss, and at least one survival-related outcome variable (eg., non-relapse mortality, overall survival and/or relapse). Based on the findings of this review, body composition, whether evaluated before or during HSCT, can impact a wide variety of post-transplant outcomes. This speaks to the importance of evaluating patients pre-transplant, identifying potential risk factors for worsened outcomes, and providing immediate interventions in order to optimize transplant outcomes.

Mechanisms by Which Obesity Promotes Acute Graft-Versus-Host Disease in Mice

The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by the occurrence of acute and chronic graft-versus-host disease (GVHD). We have recently demonstrated that obesity results in exacerbated acute gastrointestinal GVHD in both mouse models and clinical outcomes due to increased pro-inflammatory cytokine responses and microbiota alterations. We therefore wanted to delineate the role of the various parameters in obesity, adiposity, effects of high-fat (HF) diet, and the role of microbiome on GVHD pathogenesis, by taking advantage of a mouse strain resistant to diet-induced obesity (DIO). Female BALB/c mice are resistant to DIO phenotype with approximately 50% becoming DIO under HF diets. The DIO-susceptible recipients rapidly succumb to acute gut GVHD, whereas the DIO-resistant recipient littermates, which do not become obese, are partially protected from GVHD, indicating that being on HF diet alone contributes to but is not the primary driver of GVHD. Microbiome assessment revealed restricted diversity in both cohorts of mice, but coprophagy normalizes the microbiota in mice housed together. We then individually housed DIO-resistant, DIO-susceptible, and lean control mice. Notably, each of the individually housed groups demonstrates marked restricted diversity that has been shown to occur from the stress of single housing. Despite the restricted microbiome diversity, the GVHD pathogenesis profile remains consistent in the group-housed mice, with the lean control single-housed mice exhibiting no acute GVHD and DIO-resistant recipients showing again partial protection. These results demonstrate that the deleterious effects of obesity on acute gut GVHD are critically dependent on adiposity with the HF diet also playing a lesser role, and the microbiome alterations with obesity instead appear to fuel ongoing acute GVHD processes.