Association of anthropometric measures with all-cause and cause-specific mortality in US adults: revisiting the obesity paradox

OBJECTIVE

Previous studies have shown that the obesity paradox exists in a variety of clinical settings, whereby obese individuals have lower mortality than their normal-weight counterparts. It remains unclear whether the association between obesity and mortality risk varies by anthropometric measures. The purpose of this study is to examine the association between various anthropometric measures and all-cause and cause-specific mortality in US adults.

METHODS

This cohort study included data from the National Health and Nutrition Examination Survey between 2009 and 2018, with a sample size of 28,353 individuals weighted to represent 231 million US adults. Anthropometric measurements were obtained by trained technicians using standardized methods. Mortality data were collected from the date of enrollment through December 31, 2019. Weighted Cox proportional hazards models, restricted cubic spline curves, and cumulative incidence analyses were performed.

RESULTS

A total of 2091 all-cause deaths, 606 cardiovascular deaths, 519 cancer deaths, and 966 other-cause deaths occurred during a median follow-up of 5.9 years. The association between body mass index (BMI) and mortality risk was inversely J-shaped, whereas the association between waist-to-height ratio (WHtR) and mortality risk was positively J-shaped. There was a progressive increase in the association between the WHtR category and mortality risk. Compared with the reference category of WHtR < 0.5, the estimated hazard ratio (HR) for all-cause mortality was 1.004 (95% confidence interval [CI] 1.001-1.006) for WHtR 0.50-0.59, 1.123 (95% CI 1.120-1.127) for WHtR 0.60-0.69, 1.591 (95% CI 1.584-1.598) for WHtR 0.70-0.79, and 2.214 (95% CI 2.200-2.228) for WHtR ≥ 0.8, respectively. Other anthropometric indices reflecting central obesity also showed that greater adiposity was associated with higher mortality.

CONCLUSIONS

Anthropometric measures reflecting central obesity were independently and positively associated with mortality risk, eliminating the possibility of an obesity paradox.

Unraveling the BMI paradox in different renal cortical tumors: insights from the INMARC registry

OBJECTIVE

To investigate impact of body mass index (BMI) on survival across different histologies and stages of renal cell carcinoma (RCC).

METHODS

We conducted a retrospective multicenter analysis of clear cell (ccRCC) and non-ccRCC. Obesity was defined according to the WHO criteria (non-Asian BMI >30 Kg/m2, Asian BMI >27.5 Kg/m2). Multivariable analysis (MVA) via Cox regression model was conducted for all-cause (ACM), cancer-specific mortality (CSM) and recurrence.

RESULTS

A total of 3,880 patients with a median follow-up of 31 (IQR 9-64) months were analyzed. Overall, 1,373 (35.3%) were obese; 2,895 (74.6%) were ccRCC and 985 (25.3%) were non-ccRCC (chRCC 246 [24.9%], pRCC 469 [47.6%] and vhRCC 270 [27.4%]). MVA in ccRCC revealed obesity associated with decreased risk of ACM, CSM and recurrence (hazard ratio [HR] 0.80, P = 0.044; HR 0.71, P = 0.039; HR 0.73, P = 0.012, respectively), while in non-ccRCC was not associated with decreased risk of ACM, CSM, and recurrence (P = 0.84, P = 0.53, P = 0.84, respectively). Subset analysis in stage IV ccRCC demonstrated obesity as associated with a decreased risk of ACM, CSM, and recurrence (HR 0.68, P = 0.04; HR 0.59, P = 0.01; HR 0.59, P = 0.01, respectively), while in stage I-III ccRCC was not (P = 0.21; P = 0.30; P = 0.19, respectively).

CONCLUSION

Our findings refute a broad "obesity paradox" for RCC. Obesity was not associated with improved survival in non-ccRCC and in nonmetastatic ccRCC, while metastatic ccRCC patients with obesity had improved survival outcomes.

Roles of general and central adiposity in cardiometabolic multimorbidity: revisiting the obesity paradox using a multistate model

OBJECTIVE

The objective of this study was to evaluate the associations of general and central obesity with risk of first cardiometabolic disease (FCMD), cardiometabolic multimorbidity (CMM), and death.

METHODS

A total of 86,169 participants who were CMD-free were included from the Kailuan cohort and categorized into four groups by quartiles of BMI, waist to hip ratio (WHR), weight-adjusted waist index, and waist to height ratio. We defined FCMD as the first onset of diabetes, stroke, or myocardial infarction and CMM as co-occurrence of at least two CMDs. Multistate models were used to estimate hazard ratios and 95% CI.

RESULTS

A total of 18,461 participants developed FCMD, of whom 1476 progressed to CMM, and 10,009 died during follow-ups. Both general and central adiposity indices increased the risk of transition from baseline to FCMD and from FCMD to CMM. However, compared with the first quartile, the hazard ratio (95% CI) of the fourth quartile of BMI was 0.86 (95% CI: 0.80-0.91) for transition from health to death and 0.66 (95% CI: 0.59-0.74) from FCMD to death, whereas the corresponding estimates of WHR were 1.22 (95% CI: 1.14-1.31) and 1.16 (95% CI: 1.02-1.32), respectively.

CONCLUSIONS

Central adiposity indices such as WHR were associated with an increased risk of CMD and mortality, showing no evidence for the obesity paradox and thereby supporting a shift of public focus from BMI only to both general obesity and adiposity distribution.

[Morphofunctional Analysis of the Role of Epicardial Adipose Tissue in the Formation of the Obesity Paradox in Chronic Heart Failure]

Based on the available modern medical literature, the article summarizes data on the morpho-functional significance of epicardial adipose tissue (EAT) in health and heart failure, analyzes the likelihood and reliability of the formation of the obesity paradox, and also discusses its possible morpho-functional mechanisms. The authors reviewed and analyzed the consequences of the obesity paradox in the aspect of the normal EAT phenotype protectivity. The review proposed ways of further research in this direction aimed at a deep anatomical and physiological analysis and at determining the morpho-functional role of EAT in the adaptive mechanisms of myocardial trophic provision, which may be an important part of the pathogenetic connection between obesity and CHF and, therefore, can improve outcomes in such patients.

Sarcopenic obesity is part of obesity paradox in dementia development: evidence from a population-based cohort study

BACKGROUND

Sarcopenic obesity, a clinical and functional condition characterized by the coexistence of obesity and sarcopenia, has not been investigated in relation to dementia risk and its onset.

METHODS

We included 208,867 participants from UK biobank, who aged 60 to 69 years at baseline. Dementia diagnoses were identified using hospital records and death register data. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models to evaluate the associations of obesity, sarcopenia, and sarcopenic obesity with dementia risk, stratified by sex. Stratified analyses were performed across dementia-related polygenic risk score (PRS). Restricted mean survival time models were established to estimate the difference and 95%CIs of dementia onset across different status. Additionally, linear regression models were employed to estimate associations of different status with brain imaging parameters. The mediation effects of chronic diseases were also examined.

RESULTS

Obese women with high PRS had a decreased risk (HR = 0.855 [0.761-0.961]), but obese men with low PRS had an increased risk (HR = 1.223 [1.045-1.431]). Additionally, sarcopenia was associated with elevated dementia risk (HRwomen = 1.323 [1.064-1.644]; HRmen = 2.144 [1.753-2.621]) in those with low PRS. Among those with high PRS, however, the association was only significant in early-life (HRwomen = 1.679 [1.355-2.081]; HRmen = 2.069 [1.656-2.585]). Of note, sarcopenic obesity was associated with higher dementia risk (HRwomen = 1.424 [1.227-1.653]; HRmen = 1.989 [1.702-2.323]), and results remained similar stratified by PRS. Considering dementia onset, obesity was associated with dementia by 1.114 years delayed in women, however, 0.170 years advanced in men. Sarcopenia (women: 0.080 years; men: 0.192 years) and sarcopenic obesity (women: 0.109 years; men: 0.511 years) respectively advanced dementia onset. Obesity, sarcopenia, and sarcopenic obesity were respectively related to alterations in different brain regions. Association between sarcopenic obesity and dementia was mediated by chronic diseases.

CONCLUSIONS

Sarcopenic obesity and sarcopenia were respectively associated with increased dementia risk and advanced dementia onset to vary degree. The role of obesity in dementia may differ by sex and genetic background.

Obesity paradox in uveal melanoma: high body mass index is associated with low metastatic risk

BACKGROUND

Metabolic factors and obesity may influence the development and progression of cancer. In this study, we examine their association with the risk of developing metastases of uveal melanoma.

METHODS

Data on metabolic factors, medications, serum leptin levels, tumour leptin receptor RNA expression and clinical outcomes were examined in three cohorts. HRs for metastasis and cumulative incidences of melanoma-related mortality were calculated, and the levels of tumour leptin receptor expression were compared with prognostic factors including BAP1 mutation, and tumour cell morphology.

RESULTS

Of 581 patients in the main cohort, 116 (20%) were obese and 7 (1 %) had metastatic disease at presentation. In univariate Cox regressions, tumour diameter, diabetes type II and use of insulin were associated with metastases, but patients with obesity had a lower risk. The beneficial prognostic implication of obesity was retained in multivariate regressions. In competing risk analyses, the incidence of melanoma-related mortality was significantly lower for patients with obesity. Serum leptin levels≥median were associated with a reduced risk for metastasis, independent of patient sex and cancer stage in a separate cohort (n=80). Similarly, in a third cohort (n=80), tumours with BAP1 mutation and epithelioid cells had higher leptin receptor RNA expression levels, which have a negative correlation with serum leptin levels.

CONCLUSION

Obesity and elevated serum leptin levels are associated with a lower risk for developing metastases and dying from uveal melanoma.

Association of systemic inflammation with the obesity paradox in cancer: results from multi-cohort studies

AIMS

This study aimed to explore whether the obesity paradox exists in overall and specific cancers and to investigate the role of systemic inflammation in the obesity paradox.

METHODS

The Cox proportional hazard model was used to explore the relationship between body mass index (BMI) and all-cause mortality. The mediated effect was used to investigate the proportion of systemic inflammation mediating the relationship between BMI and cancer survival risk.

RESULTS

The survival probability showed a step-like increase with an increase in BMI regardless of pathological stage. Approximately 10.8%-24.0% of the overall association between BMI and all-cause mortality in cancer was mediated by inflammation. In the internal validation, we found evidence of the obesity paradox in all body composition obtained using BIA, with inflammation remaining an important mediating factor. Furthermore, we also validated the existence of the obesity paradox of cancer in NHANES. Systemic inflammation remains an important factor in mediating the association between BMI and prognosis in cancer patients.

CONCLUSIONS

The obesity paradox is prevalent in most cancers, except for hepatic biliary cancer and breast cancer. Inflammation may be one of the true features of the obesity paradox in cancer.

Potential confounders of the obesity paradox in older patients following transcatheter aortic valve replacement

PURPOSE

A higher body mass index (BMI) is associated with lower mortality in older patients following transcatheter aortic valve replacement (TAVR) for severe aortic valve stenosis. The current study aimed to investigate potential confounders of association between BMI and prognosis.

METHODS

The retrospective single-center study included consecutive patients following TAVR and excluded those in whom subcutaneous fat accumulation (SFA), visceral fat accumulation (VFA), and major psoas muscle (MPM) volume were not assessed by computed tomography. Cachexia was defined as a combination of BMI < 20 kg/m2 and any biochemical abnormalities.

RESULTS

After 2 patients were excluded, 234 (age, 86 ± 5 years; male, 77 [33%]; BMI, 22.4 ± 3.8 kg/m2; SFA, 109 (54-156) cm2; VFA, 71 (35-115) cm2; MPM, 202 (161-267) cm3; cachexia, 49 [21%]) were evaluated. SFA and VFA were strongly correlated with BMI (ρ = 0.734 and ρ = 0.712, respectively), whereas MPM was weakly correlated (ρ = 0.346). Two-year all-cause mortality was observed in 31 patients (13%). Higher BMI was associated with lower mortality (adjusted hazard ratio [aHR], 0.86; 95% confidence interval [CI], 0.77-0.95). A similar result was observed in the multivariate model including SFA (aHR in an increase of 20 cm2, 0.87; 95% CI, 0.77-0.98) instead of BMI, whereas VFA was not significant. Cachexia was a worse predictor (aHR, 2.51; 95% CI 1.11-5.65).

CONCLUSIONS

Association of higher BMI with lower mortality may be confounded by SFA in older patients following TAVR. Cachexia might reflect higher mortality in patients with lower BMI.

The Obesity Paradox in the Pediatric Trauma Patient

BACKGROUND

Obesity is a chronic disease that adversely impacts patient outcomes and increasingly affecting the pediatric population. According to the CDC, in 2020 the prevalence of obesity among children and adolescents was estimated to be as high as 19.7%. The obesity paradox is the increased survival for overweight and obese adult trauma patients when compared to patients with healthy weights. The aim of this study was to analyze the impact of BMI and outcomes in the pediatric trauma population.

METHODS

Trauma patients in the 2-18 years age group and reported to the 2017-2019 National Trauma Data Bank were identified. CDC growth charts and z-scores were calculated to categorize patients into four subgroups: underweight (<5th percentile), healthy weight (5th-85th percentile), overweight (85th-95th percentile), and obesity (>95th percentile). Primary outcome studied was the mortality rate. Secondary outcomes included injury severity score (ISS), hospital length of stay (LOS), ICU LOS, and number of days on a ventilator. Continuous and categorical data were analyzed using ANOVA and Chi-squared test, respectively, using the healthy BMI category as reference group. P < 0.05 was considered significant.

RESULTS

A total of 161,458 patients [Underweight: 9148 (6%), Healthy weight: 88,009 (55%), Overweight: 26,740 (17%), and Obese: 37,561 (23%)] were included. The mean age was 11 years (SD:5.1). Total mortality for the patient set was 1825 (1.13%). The lowest mortality rate was in the obese group. The ISS was lowest in the obese group, while ICU LOS and days on ventilator were no different than control patients. Hospital LOS and transfer to rehabilitation rates were higher in the obese population.

CONCLUSION

Obesity appears to have a protective effect on mortality and significantly better secondary outcomes in the pediatric trauma population. Further study is necessary to evaluate the interplay between body weight and outcomes in pediatric trauma and disease states.

LEVEL OF EVIDENCE

III.

The obesity paradox and ventriculoperitoneal shunting in aneurysmal subarachnoid hemorrhage patients undergoing microsurgical clipping

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) can be devastating. Identifying predisposing factors is paramount in reducing aSAH-related mortality. Obesity's negative impact on health is well-established. However, the controversial "obesity paradox" in neurosurgery suggests that obesity may confer a survival advantage in SAH. We hypothesized that obesity would have a negative impact on outcomes following surgical clipping in aSAH.

METHODS

A single-institution retrospective review was performed of aSAH patients undergoing surgical clipping from 2017 to 2021. Demographics and clinically relevant variables were collected. Obesity was defined as body mass index >30. Primary outcome was death or severe disability (mRS 4-6) at last follow-up. Secondary outcome was VPS placement. Multivariable Cox proportional-hazards model identified predictors of poor outcome. Kaplan-Meier curves identified survivorship differences between obese and non-obese patients.

RESULTS

Poor outcome occurred in 11 of 52 total patients (21.2 %). There were no differences in demographics or distribution of Hunt Hess (HH), modified Fisher Grade (mFG), or external ventricular drain (EVD) placement between obese and non-obese patients. On univariate analysis, hypertension, older age, and non-obesity were predictive of poor outcome. On multivariable analysis, only obesity remained significant, suggesting a protective effect from poor outcome (HR 0.45 [0.21-0.95], p = 0.037). VPS placement occurred in 6 (11.5 %) patients for which obesity was not a significant predictor.

CONCLUSIONS

Obesity may have a protective effect against poor outcome following surgical clipping in aSAH. Additionally, obesity does not appear to increase rate of EVD conversion to VPS. Thus, our study suggests that obesity should not preclude patients from open surgical intervention when clinically appropriate.

The Association between Obesity and Reduced Weight-Adjusted Bone Mineral Content in Older Adults: A New Paradigm That Contrasts with the Obesity Paradox

The relationship between body weight and bone mass in the elderly remains unclear, and whether obesity is a protective factor is still a matter of debate. For this reason, the aim of this study is to assess the association between body mass index (BMI) and bone mineral content adjusted by body weight, expressed as a percentage (w-BMC%), and to test the validity of the obesity paradox in this context. A cohort of 1404 older adults was categorized according to the World Health Organization's BMI cut-off points and completed a total and segmental body composition measurement by means of a dual X-ray absorptiometry scan. Individuals with obesity displayed a lower mean w-BMC% (3.06 ± 0.44%; 2.60 ± 0.37%) compared to those who were normal-weight (3.95 ± 0.54%; 3.38 ± 0.48%) and overweight (3.06 ± 0.44%; 3.04 ± 0.37%) in both genders. Linear regression analysis also showed a negative association between BMI and w-BMC% in males (β = -0.09; p < 0.001) and females (β = -0.06; p < 0.001). Finally, among individuals with obesity, and after adjusting for age, the linear regression models revealed a significant decrease of 0.75% and 0.28% in w-BMC% for every one-unit increase in the trunk fat/appendicular lean mass ratio in both males (β = -0.749; p < 0.0001) and females (β = -0.281; p < 0.001). In conclusion, we suggest a new paradigm regarding the impact of obesity on bone mass, in which the former does not appear to be a protective factor of the latter, especially in individuals with central obesity and low muscle mass.

Update on obesity, the obesity paradox, and obesity management in heart failure

Obesity is a major public health challenge worldwide. It is costly, predisposes to many cardiovascular (CV) diseases (CVD), is increasing at an alarming rate, and disproportionately affects people of low-socioeconomic status. It has a myriad of deleterious effects on the body, particularly on the CV system. Obesity is a major risk factor for heart failure (HF) and highly prevalent in this population, particularly in those with HF with preserved ejection fraction (HFpEF), to the extent that an obesity HFpEF phenotype has been proposed in the literature. However, once HF is developed, an obesity paradox exists where those with obesity have better short- and mid-term survival than normal or underweight individuals, despite a greater risk for hospitalizations. It may be argued that excess energy reserve, younger patient population, higher tolerability of HF therapy and better nutritional status may account for at least part of the obesity paradox on survival. Furthermore, body mass index (BMI) may not be an accurate measure of body composition, especially in HF, where there is an excess volume status. BMI also fails to delineate fat-free mass and its components, which is a better predictor of functional capacity and cardiorespiratory fitness (CRF), which particularly is increasingly being recognized as a risk modifier in both healthy individuals and in persons with comorbidities, particularly in HF. Notably, when CRF is accounted for, the obesity paradox disappears, suggesting that improving CRF might represent a therapeutic target with greater importance than changes in body weight in the setting of HF. In this narrative review, we discuss the current trends in obesity, the causal link between obesity and HF, an update on the obesity paradox, and a description of the major flaws of BMI in this population. We also present an overview of the latest in HF therapy, weight loss, CRF, and the application of these therapeutic approaches in patients with HF and concomitant obesity.

Obesity paradox in older sarcopenic adults - a delay in aging: A systematic review and meta-analysis

The prognostic significance of obesity in sarcopenic adults is controversial. This systematic review and meta-analysis aimed to investigate the effect of additional obesity on health outcomes in sarcopenia. MEDLINE, EMBASE, Scopus and CENTRAL were systematically searched for studies to compare health outcomes of adults with sarcopenic obesity (SO) to those of sarcopenic non-obese (SNO) adults. We also considered the methods of assessing obesity. Of 15060 records screened, 65 papers were included (100612 participants). Older community-dwelling SO adults had 15% lower mortality risk than the SNO group (hazard ratio, HR: 0.85, 95% confidence interval 0.76, 0.94) even when obesity was assessed by measurement of body composition. Additionally, meta-regression analysis revealed a significant negative linear correlation between the age and the HR of all-cause mortality in SO vs. SNO community-dwelling adults, but not in severely ill patients. Compared with SNO, SO patients presented lower physical performance, higher risk for metabolic syndrome, but similar cognitive function, risk of falls and cardiovascular diseases. Age-related obesity, SO and later fat loss leading to SNO represent consecutive phases of biological aging. Additional obesity could worsen the health state in sarcopenia, but above 65 years SO represents a biologically earlier phase with longer life expectancy than SNO.

The Obesity Paradox in Thyroid Surgery: Is Higher BMI Protective Against Hypoparathyroidism?

BACKGROUND

With a demonstrated association between adiposity and parathyroid hormone (PTH) levels, we hypothesized that patients with a higher body mass index (BMI) would have lower rates of postoperative hypoparathyroidism following total thyroidectomy.

METHODS

retrospective review of patients undergoing total thyroidectomy from 2015 to 2021. Demographics, BMI, surgical indications, and laboratory data including pre- and postoperative PTH values were examined.

RESULTS

Of the 352 patients with complete clinicopathologic data, most were female (n = 272, 77.3%) with an average age of 42.7 (SD+/-19.4). Obese (BMI 30-39.99) was most common BMI group (n = 108, 30.8%), with 11.7% (n = 41) morbidly obese (BMI > 40). Morbidly obese patients had significantly higher postoperative PTH levels than BMI < 18.5 (46.0 vs 19.3 pg/mL, P = .004). Patient race was significantly associated with pre- and postoperative PTH (P = .03, P = .004.) On multivariable analysis, preoperative PTH, race, and BMI were independent predictors of higher postoperative PTH (P < .05 for all).

DISCUSSION

Patients with higher BMI and non-white race have relative protection from postoperative hypoparathyroidism.

The obesity paradox in multiple myeloma: A report from Multiple Myeloma Research Foundation (MMRF) dataset

BACKGROUND

Obesity is a risk factor for multiple myeloma (MM). However, we still lack knowledge on the clinical course of obese MM patients in a broad view.

METHODS

Here, we reviewed 568 MM patients recorded in the Multiple Myeloma Research Foundation (MMRF) coMMpass dataset. Patients were divided into the normal and obese groups according body mass index (BMI) at diagnosis, and then the baseline characteristics, cytogenetic abnormalities, treatment variability, and survival outcomes were evaluated in the obese cohort.

RESULTS

We found no differences in the characteristics when comparing normal and obese MM patients other than more male in the obese part (50.4% vs. 59.9%, p = 0.024). Compared with the normal BMI patients, median overall survival (OS) was shorter for obese MM patients but without significant meaning (82.3 vs. 95.3 months, p = 0.25). However, in the subgroup analysis, obese MM patients younger than 65 years had significantly inferior OS than that in the normal category (p = 0.047). We also found obese MM patients had a higher overall response rate (ORR) compared with normal BMI patients (92.7% vs. 88.6%, p = 0.037). Additionally, obese patients seemed to achieve faster best response during first-line therapy.

CONCLUSIONS

Obesity assumes a paradoxical function in the clinical trajectory of myeloma.

Obesity paradox in patients with non-small cell lung cancer undergoing immune checkpoint inhibitor therapy

BACKGROUND

The obesity paradox in patients with advanced non-small cell lung cancer receiving immune checkpoint inhibitor therapy has been observed, but its underlying mechanism is not fully understood. We aimed to investigate whether body composition affects the prognostic impact of obesity, as determined by body mass index (BMI), on survival.

METHODS

This retrospective study evaluated the data collected from Asian patients who were treated with immune checkpoint inhibitors for advanced non-small cell lung cancer between October 2015 and October 2021. We used abdominal cross-sectional imaging to calculate the skeletal muscle and visceral fat indices (cm2 /m2 ) by dividing the cross-sectional areas of the skeletal muscle and visceral fat by the height squared. Cox proportional-hazards regression was performed to determine the correlation between BMI according to the Asia-Pacific classification, body composition metrics and overall survival.

RESULTS

We analysed the data of 820 patients (630 men and 190 women, with a mean age of 64.3 years [standard deviation: 10.4 years]) and observed 572 (69.8%) deaths with the 1-year mortality rate of 0.58 (95% confidence interval, 0.55-0.62). Obese BMI was associated with longer overall survival, independent of clinical covariates (hazard ratio, 0.64; 95% confidence interval: 0.52-0.80). The prognostic value of obese BMI remained after additional adjustments for skeletal muscle index (hazard ratio, 0.68; 95% confidence interval, 0.53-0.87) or visceral fat index (hazard ratio, 0.54; 95% confidence interval: 0.41-0.70). No association was observed between sex and the impact of BMI on overall survival (P-value for interaction >0.05).

CONCLUSIONS

In Asian patients with advanced non-small cell lung cancer who received immune checkpoint inhibitors, obese BMI was associated with favourable overall survival independent of skeletal muscle or visceral fat mass.

The obesity paradox in intracerebral hemorrhage: a systematic review and meta-analysis

Background

Intracerebral hemorrhage (ICH) has a mortality rate which can reach 30-40%. Compared with other diseases, obesity is often associated with lower mortality; this is referred to as the 'obesity paradox'. Herein, we aimed to summarize the studies of the relations between obesity and mortality after ICH.

Method

For this systematic review and meta-analysis (PROSPERO registry CRD42023426835), we conducted searches for relevant articles in both PubMed and Embase. Non-English language literature, irrelevant literature, and non-human trials were excluded. All included publications were then qualitatively described and summarized. Articles for which quantitative analyses were possible were evaluated using Cochrane's Review Manager.

Results

Ten studies were included. Qualitative analysis revealed that each of the 10 studies showed varying degrees of a protective effect of obesity, which was statistically significant in 8 of them. Six studies were included in the quantitative meta-analysis, which showed that obesity was significantly associated with lower short-term (0.69 [0.67, 0.73], p<0.00001) and long-term (0.62 [0.53, 0.73], p<0.00001) mortality. (Data identified as (OR [95%CI], p)).

Conclusion

Obesity is likely associated with lower post-ICH mortality, reflecting the obesity paradox in this disease. These findings support the need for large-scale trials using standardized obesity classification methods.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023426835, identifier CRD42023426835.

Significance of Adipose Tissue Quantity and Distribution on Obesity Paradox in Heart Failure

Obesity is a predictor of the development of systolic and diastolic heart failure (HF), but once established, patients with HF and obesity have better outcomes than their leaner counterparts, a phenomenon termed the "obesity paradox." We sought to investigate the impact of adipose tissue quantity and distribution, measured by way of computed tomography, on outcomes in patients with HF. Patients admitted for acute decompensated HF between January 2017 to December 2018 were retrospectively analyzed. Body composition measurements were made on computed tomography of the abdomen/pelvis. Visceral, subcutaneous, and intermuscular adipose tissues were measured at the mid-third lumbar vertebra, along with skeletal muscle and waist circumference. Paracardial (pericardial and epicardial) adipose tissue was measured at the mid-eight thoracic vertebra. Visceral adipose tissue index (VATI) and subcutaneous adipose tissue index (SATI), along with skeletal muscle index, were indexed for patient height. A total of 200 patients were included, 44.5% female. Body mass index and waist circumference did not significantly predict outcomes. Patients with high SATI (highest sex-stratified tertile) had significantly better survival (hazard ratio 0.58, 95% confidence interval 0.39 to 0.87, p = 0.009), whereas high VATI was nonsignificant. Patients were further divided into 4 groups based on both VATI and SATI. One- and 4-year mortality risks were lowest in those with low VATI high SATI compared with the other groups; this persisted after multivariable adjustment for covariates, including albumin and skeletal muscle index. In conclusion, the "obesity paradox" appears to be largely driven by subcutaneous adipose tissue, independent of nutrition or skeletal muscle.

The Obesity Paradox: A Nonlinear Relationship Between 30-Day Postoperative Complications and Body Mass Index After Total Shoulder Arthroplasty

BACKGROUND

An inverse relationship coined the "obesity paradox" has been propositioned, in which body mass index (BMI) may be contradictorily protective in patients undergoing surgery or treatment of chronic disease. This study sought to investigate the BMI associated with the lowest rate of medical complications after total shoulder arthroplasty (TSA).

METHODS

The American College of Surgeons National Surgical Quality Improvement Project database was queried to identify adults who underwent elective primary TSA between January 2012 and December 2020. Thirty-day postoperative medical complications were extracted, which included death, readmission, pneumonia, pulmonary embolism, renal failure, and cardiac arrest, among others. BMI was classified into five categories (underweight [BMI <18.5 kg/m 2 ], normal weight [BMI ≥18.5 and <25 kg/m 2 ], overweight [BMI ≥25 and <30 kg/m 2 ], obese [BMI ≥30 and <40 kg/m 2 ], and morbidly obese [BMI ≥40 kg/m 2 ]). We examined the risk of any 30-day postoperative complications and BMI categorically and on a continuous basis using multivariable logistic regression controlling for age, sex, procedure year, and comorbidities.

RESULTS

Of the 31,755 TSAs, 84% were White, 56% were female, and the average age of patients was 69.2 ± 9.3 years. Thirty-day postoperative medical complications occurred in 4.53% (n = 1,440). When assessed on a continuous basis, the lowest risk was in patients with a BMI between 30 and 35 kg/m 2 . Underweight individuals (BMI <18.5 kg/m 2 ) had the highest postoperative complication rates overall. The probability of medical complications increased with age and was greater for female patients.

CONCLUSION

The relationship between BMI and complication risk in TSA is nonlinear. A BMI between 30 and 35 kg/m 2 was associated with the lowest risk of medical complications after TSA, and BMI<18.5 kg/m 2 had the highest risk overall, indicating some protective aspects of BMI against 30-day medical complications. Thus, obesity alone should not preclude patients from TSA eligibility, rather surgical candidacy should be evaluated in the context of patients' overall health and likelihood of benefit from TSA.

LEVEL OF EVIDENCE

III, Retrospective Comparative Study.

Obesity Paradox in Heart Failure Revisited: Etiology as Effect Modifier

The prognostic value of overweight/obesity in heart failure (HF) may vary according to HF etiologies. We aim to determine whether body mass index has differential impacts on survival among hospitalized HF patients with varying etiologies. Consecutive hospitalized HF patients between December 2006 and December 2017 were included. Multivariable analyses, including Cox proportional hazard models and restricted cubic splines, were used to investigate the impact of body mass index on mortality by HF etiology. Among the 3,836 patients included (mean age 57.1 years, 28.4% women), 1,475 (38.5%) were identified as having ischemic etiology. Of the remaining 2,361 patients with non-ischemic etiologies, dilated cardiomyopathy (DCM) accounted for 45.6% (n = 1,077). The rest of the patients were uniformly classified as having non-ischemic-non-DCM HF. The unadjusted data demonstrated an adiposity-related survival paradox in HF across all etiologies. However, the paradox holds only among non-ischemic-non-DCM HF patients after multivariate adjustment, wherein overweight patients exhibit the lowest mortality compared with their normal-weight counterparts (adjusted hazard ratio [aHR] 0.69, 95% confidence interval [CI] 0.52 to 0.91), with a nadir in mortality risk at 28.18 kg/m2. Similar survival benefits of overweight were not demonstrated in ischemic or DCM HF patients (ischemic etiology: aHR 1.07, 95% CI 0.84 to 1.36; DCM etiology: aHR 0.97, 95% CI 0.74 to 1.28). In conclusion, being overweight or obese does not confer better survival in HF patients of ischemic or DCM etiology, and the prognostic benefit of being overweight is maintained only in non-ischemic-non-DCM HF patients. Pathophysiologic interpretations are warranted, and whether patients of certain etiologies would benefit from weight reduction needs to be explored.

Moving beyond frailty: Obesity paradox persists in lung resection

BACKGROUND

The apparent protective effect of high body mass index on postoperative outcomes, termed the "obesity paradox," has been postulated to reflect the relative frailty of patients without obesity. We wanted to examine the independent association between body mass index and outcomes after anatomic lung resection.

METHODS

All adults undergoing elective lung resection for cancer were identified in the 2012-2020 National Surgical Quality Improvement Program. The modified Frailty Index quantified degree of patient frailty. Malnutrition was defined as a preoperative serum albumin <3.5g/dL. Multivariable regressions were used to examine the independent association of body mass index and major adverse events, analyzed as a composite of 30-day mortality, postoperative complications, and unplanned reoperation.

RESULTS

Of an estimated 20,099 patients meeting study criteria, 6,424 (32.0%) had obesity. Relative to others, patients with obesity were significantly younger (49.3 vs 50.3 years), more commonly White (78.1 vs 74.9%), and more frequently frail (modified Frailty Index >1: 35.7 vs 22.5%, all P < .001). There was no significant difference in malnutrition rates (7.6 vs 8.4%, P = .05) or extent of resection between groups. After adjustment, obesity was associated with decreased odds of major adverse events (adjusted odds ratio 0.86, 95% confidence interval 0.78-0.94).

CONCLUSION

The present findings uphold the canonical obesity paradox in anatomic lung resection, despite adjustment for frailty and malnutrition. Further studies are warranted to characterize the nature of this association; however, our results may inform efforts to optimize risk stratification and patient selection for surgical intervention.

Obesity and the obesity paradox in patients with severe COVID-19

OBJECTIVE

To test the presence of the obesity paradox in two cohorts of patients hospitalized for COVID-19.

DESIGN

Two multicenter prospective cohorts.

SETTING

Three fourth level institutions.

PATIENTS

Adults hospitalized in the general ward for confirmed COVID-19 in the three institutions and those admitted to one of the 9 critical care units of one of the institutions.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

Categorized weight and its relationship with admission to the ICU in hospitalized patients and death in the ICU.

RESULT

Of 402 hospitalized patients, 30.1% were obese. Of these, 36.1% were admitted to the ICU vs. 27.1% of non-obese patients. Of the 302 ICU patients, 46.4% were obese. Of these, mortality was 45.0% vs. 52.5% for non-obese. The requirement to transfer hospitalized patients to the ICU admission get a HR of 1.47 (95%CI 0.87-2.51, p = 0.154) in the multivariate analysis. In intensive care patients, an HR of 0.99 (95%CI: 0.92-1.07, p = 0.806) was obtained to the association of obesity with mortality.

CONCLUSIONS

The present study does not demonstrate an association between obesity and risk of inpatient transfer to intensive care or death of intensive care patients due to COVID-19 therefore, the presence of an obesity paradox is not confirmed.

Obesity paradox or hypoxia preconditioning: How obstructive sleep apnea modifies the Obesity-MI relationship

OBJECTIVES

The objective of this study was to evaluate the interaction between obesity and obstructive sleep apnea on acute MI in hospital mortality.

METHODS

This retrospective cohort study utilized Veterans Health Administration data from years 1999-2020. Participants were categorized according to their body mass index (BMI) to non-obese (BMI <30) and obese (BMI ≥30) groups. Clinical obstructive sleep apnea (SA) diagnosis was confirmed using ICD9/10 codes and the study subgroups included non-obese with no obstructive sleep apnea (nOB-nSA), non-Obese with obstructive sleep apnea (nOB-SA), obese with no obstructive sleep apnea (OB-nSA), and obese with obstructive sleep apnea (OB-SA). The primary outcome was odds ratio of in-hospital mortality during the hospitalization with acute MI as the principal diagnosis adjusted for age, gender, race, ethnicity, and Charlson comorbidity index (CCI) with the nOB-nSA group as the comparison group.

RESULTS

Among 72,036 veterans with acute-MI hospitalization, individuals with obesity and obstructive sleep apnea (OB-SA) had the lowest in-hospital mortality rate (1.0%) compared to those without obesity and obstructive sleep apnea (nOB-nSA, 2.8%), with obesity but without obstructive sleep apnea (OB-nSA, 2.4%), and with obesity and obstructive sleep apnea (nOB-SA, 1.4%). The adjusted odds ratio for mortality, compared to nOB-nSA, was 9% higher but not significant in OB-nSA (aOR, 1.09, 95%CI: 0.95, 1.25), 46% lower in OB-nSA (aOR, 0.54, 95%CI: 0.45, 0.66), and 52% lower in OB-SA (aOR, 0.48: 95%CI: 0.41, 0.57).

CONCLUSION

Our data suggest that the association between obesity and improved survival in acute MI is largely driven by the presence of sleep apnea.

Delay Discounting and the Income-Food Insecurity-Obesity Paradox in Mothers

Food insecurity, defined as unpredictable access to food that may not meet a person's nutritional needs, is paradoxically associated with higher BMI (kg/m2) and obesity. Research has shown delay discounting, a behavioral economic measure of the preference for immediate rather than delayed rewards, is related to higher BMI, and moderates the relationship between income and food insecurity. Based on this research, we used regression models to test whether delay discounting, consideration of future consequences, and perceived stress were atemporal mediators of the food insecurity-BMI relation in 313 mothers, controlling for demographic variables. A secondary aim was to replicate the finding that delay discounting moderates the relationship between low income and high food insecurity. Results showed that low income was associated with higher food insecurity, and higher food insecurity was associated with higher BMI. Delay discounting was the only variable that was indirectly related to both paths of the food-insecurity-BMI relation. Delay discounting accounted for 22.2% of the variance in the low-income-food insecurity-obesity relation, and the total model accounted for 38.0% of the variance. The relation between low income and food insecurity was moderated by delay discounting. These data suggest that delay discounting is a potential mediator of the relationship between food insecurity and high BMI, which suggests reducing discounting in the future could be a novel target to reduce food insecurity and help people with food insecurity to reduce their excess body weight. Trial Registration. This trial is registered with NCT02873715.

The obesity paradox in Japanese COVID-19 patients

Purpose: To investigate the effect of obesity on mortality and invasive respiratory care (IRC) in patients with COVID-19. Methods: We studied 1,105 patients for 34 months and collected data. The primary outcome was all-cause death at 29 days. The secondary outcome was IRC indicated by a pulse oximetry rate below 93% at a mask oxygenation rate of 5 L/min or more. Results: Age- and sex-adjusted multivariate regression analysis for 29-day deaths showed the significance of body mass index (BMI) > 19.6 kg/m2 (odds ratio 0.117, 95% confidence interval 0.052-0.265, P<0.001). The graphs with BMI in the abscissa showed, within a BMI between 11 and 25 kg/m2, a decreasing pattern for mortality and IRC rate, and no increase in overweight. Conclusion: In Japanese COVID-19 patients, the risk of mortality and the IRC rate decreased in underweight patients and remained low in overweight patients, suggesting the importance of the obesity paradox.

APOE genotypes modify the obesity paradox in dementia

BACKGROUND

While obesity in midlife is a risk factor for dementia, several studies suggested that obesity also protected against dementia, hence so-called obesity paradox. The current study aims to address the relationship between apolipoprotein E (APOE) genotype and obesity in dementia.

METHODS

Clinical and neuropathological records of the National Alzheimer's Coordinating Center (NACC) in the USA, which longitudinally followed approximately 20 000 subjects with different cognitive statues, APOE genotype and obesity states, were reviewed.

RESULTS

Obesity was associated with cognitive decline in early elderly cognitively normal individuals without APOE4, especially those with APOE2. Neuropathological analyses adjusted for dementia status showed that APOE2 carriers tended to have more microinfarcts and haemorrhages due to obesity. On the other hand, obesity was associated with a lower frequency of dementia and less cognitive impairment in individuals with mild cognitive impairment or dementia. Such trends were particularly strong in APOE4 carriers. Obesity was associated with fewer Alzheimer's pathologies in individuals with dementia.

CONCLUSIONS

Obesity may accelerate cognitive decline in middle to early elderly cognitive normal individuals without APOE4 likely by provoking vascular impairments. On the other hand, obesity may ease cognitive impairment in both individuals with dementia and individuals at the predementia stage, especially those with APOE4, through protecting against Alzheimer's pathologies. These results support that APOE genotype modifies the obesity paradox in dementia.

Obesity Paradox in the Intrahospital and Follow-Up Phases of the Acute Coronary Syndrome: A Meta-Analysis and Systematic Review

BACKGROUND

Obesity is an important risk factor for the development of dyslipidemia, diabetes mellitus, hypertension, coronary artery disease, ventricular dysfunction, congestive heart failure (HF), stroke, and cardiac arrhythmias.

OBJECTIVES

This meta-analysis brings comprehensive evaluation about still controversial association between the body mass index (BMI) and the outcomes of acute coronary syndrome.

METHOD

PubMed/ScienceDirect databases were systematically searched for studies with baseline parameters, primary (HF, cardiogenic shock, cardiac arrest, reinfarction, stroke, death, total in-hospital complications) and secondary outcomes (reinfarction, stroke, death, total major adverse cardiovascular events [MACE]) in relation to BMI strictly classified into four groups (underweight [<18.5 kg/m2], normal weight [18.5-24.9 kg/m2], overweight [25.0-29.9 kg/m2], and obese [≥30.0 kg/m2], grouped into mildly obese [30.0-34.9 kg/m2] and severely obese [≥35.0 kg/m2]).

RESULTS

We included 24 studies, with 585,919 participants (55.5% males), aged 66.8 years. Underweight was negatively associated with hypertension, hyperlipidemia and diabetes, and positively with primary outcomes {HF (odds ratio [OR] = 1.37, confidence interval [CI] [1.15-1.63]), cardiogenic shock (OR = 1.43, CI [1.04-1.98]), stroke (OR = 1.21, CI [1.05-1.40]), overall death (OR = 1.64, CI [1.20-2.26]), total in-hospital complications (OR = 1.39, CI [1.24-1.56])} and secondary outcomes during 34-month follow-up {cardiovascular/overall death (OR = 3.78, CI [1.69-8.49]/OR = 2.82, CI [2.29-3.49]), respectively, total MACE (OR = 2.77, CI [2.30-3.34])} (for all p < 0.05). Obesity had positive association with hypertension, hyperlipidemia, diabetes and smoking, and negative with primary outcomes {reinfarction (OR = 0.83, CI [0.76-0.91]), stroke (OR = 0.67, CI [0.54-0.85]), overall death (OR = 0.55, CI [0.49-0.63]), total in-hospital complications (OR = 0.81, CI [0.70-0.93])} and secondary outcomes {cardiovascular/overall death (OR = 0.77, CI [0.66-0.88]/OR = 0.62, CI [0.53-0.72]), respectively, total MACE (OR = 0.63, CI [0.60-0.77])} (for all p < 0.05). This negative association with several primary outcomes (cardiogenic shock, overall death, total in-hospital complications) and secondary outcomes (cardiovascular/overall death, total MACE) was more pronounced in mild obesity (p < 0.05). These results give an "obesity paradox" with a bimodal pattern (slightly U-shaped).

CONCLUSIONS

Obesity is positively associated with traditional cardiovascular risk factors and negatively with primary and secondary outcomes, which confirms the persistence of overall "obesity paradox."

Undocumented Latino Immigrants and the Latino Health Paradox

INTRODUCTION

Despite having worse healthcare access and other social disadvantages, immigrants have, on average, better health outcomes than U.S.-born individuals. For Latino immigrants, this is known as the Latino health paradox. It is unknown whether this phenomenon applies to undocumented immigrants.

METHODS

This study used restricted California Health Interview Survey data from 2015 to 2020. Data were analyzed to test the relationships between citizenship/documentation status and physical and mental health among Latinos and U.S.-born Whites. Analyses were stratified by sex (male/female) and length of U.S. residence (<15 years/>= 15 years).

RESULTS

Undocumented Latino immigrants had lower predicted probabilities of reporting any health condition, asthma, and serious psychological distress and had a higher probability of overweight/obesity than U.S.-born Whites. Despite having a higher probability of overweight/obesity, undocumented Latino immigrants did not have probabilities of reporting diabetes, high blood pressure, or heart disease different from those of U.S.-born Whites after adjusting for having a usual source of care. Undocumented Latina women had a lower predicted probability of reporting any health condition and a higher predicted probability of overweight/obesity than U.S.-born White women. Undocumented Latino men had a lower predicted probability of reporting serious psychological distress than U.S.-born White men. There were no differences in outcomes when comparing shorter- with longer-duration undocumented Latino immigrants.

CONCLUSIONS

This study observed that the Latino health paradox may express patterns for undocumented Latino immigrants that are different from those for other Latino immigrant groups, emphasizing the importance of accounting for documentation status when conducting research on this population.

Association between Body Mass Index and Clinical Outcomes in Patients with Non-valvular Atrial Fibrillation Receiving Direct Oral Anticoagulants: A New Piece of Evidence on the Obesity Paradox from China

PURPOSE

We conducted a multicenter real-world study in China to assess the association between body mass index (BMI) and clinical outcomes in patients with atrial fibrillation (AF) taking direct oral anticoagulants (DOACs).

METHOD

This is a retrospective multicenter cohort study conducted in 15 centers in China. We collected demographic information through the hospital information system and obtained clinical events through follow-up visits to patients or relatives. Clinical outcomes include major, minor, total bleeding, thromboembolism, and all-cause death.

RESULT

A total of 6164 patients with non-valvular AF (NVAF) were included in this study. The incidence of major bleeding in patients with NVAF differed significantly by BMI category (P < 0.001), with 5.2% in the underweight group, 2.6% in the normal group, 1.4% in the overweight group, 1.1% in the obese I group, and 1.3% in the obese II group. There was no significant difference in minor, total bleeding, and thrombosis in the five groups (P = 0.493; P = 0.172; P = 0.663). All-cause death was significantly different among the five groups (P < 0.001), with 8.9% in the underweight group, 6.3% in the normal group, 4.8% in the overweight group, 2.2% in the obese I group, and 0.4% in the obese II group. High BMI was negatively associated with major bleeding (OR = 0.353, 95% CI 0.205-0.608), total bleeding (OR = 0.664, 95% CI 0.445-0.991), and all-cause death (OR = 0.370, 95% CI 0.260-0.527).

CONCLUSION

In patients with NVAF treated with DOACs, higher BMI was associated with lower major bleeding and better survival. BMI was a negative correlate of total bleeding, but not minor bleeding and thrombosis.

Obesity Paradox in Lung Diseases: What Explains It?

BACKGROUND

Obesity is a globally increasing health problem that impacts multiple organ systems and a potentially modifiable risk factor for many diseases. Obesity has a significant impact on lung function and is strongly linked to the pathophysiology that contributes to lung diseases. On the other hand, reports have emerged that obesity is associated with a better prognosis than for normal weight individuals in some lung diseases, including pneumonia, acute lung injury/acute respiratory distress syndrome, chronic obstructive pulmonary disease, and lung cancer. The lesser mortality and better prognosis in patients with obesity is known as obesity paradox. While obesity paradox is both recognized and disputed in epidemiological studies, recent research has suggested possible mechanisms.

SUMMARY

In this review, we attempted to explain and summarize these factors and mechanisms, including immune response, pulmonary fibrosis, lung function, microbiota, fat and muscle reserves, which are significantly altered by obesity and may contribute to the obesity paradox in lung diseases. We also discuss contrary literature that attributes the "obesity paradox" to confounding.

KEY MESSAGES

The review will illustrate the possible role of obesity in the prognosis or course of lung diseases, leading to a better understanding of the obesity paradox and provide hints for further basic and clinical research in lung diseases.

Obesity Paradox and Functional Outcomes in Sepsis: A Multicenter Prospective Study

OBJECTIVES

In Asian populations, the correlation between sepsis outcomes and body mass is unclear. A multicenter, prospective, observational study conducted between September 2019 and December 2020 evaluated obesity's effects on sepsis outcomes in a national cohort.

SETTING

Nineteen tertiary referral hospitals or university-affiliated hospitals in South Korea.

PATIENTS

Adult patients with sepsis ( n = 6,424) were classified into obese ( n = 1,335) and nonobese groups ( n = 5,089).

MEASUREMENTS AND RESULTS

Obese and nonobese patients were propensity score-matched in a ratio of 1:1. Inhospital mortality was the primary outcome. After propensity score matching, the nonobese group had higher hospital mortality than the obese group (25.3% vs 36.7%; p < 0.001). The obese group had a higher home discharge rate (70.3% vs 65.2%; p < 0.001) and lower median Clinical Frailty Scale (CFS) (4 vs 5; p = 0.007) at discharge than the nonobese group, whereas the proportion of frail patients at discharge (CFS ≥ 5) was significantly higher in the nonobese group (48.7% vs 54.7%; p = 0.011). Patients were divided into four groups according to the World Health Organization body mass index (BMI) classification and performed additional analyses. The adjusted odds ratio of hospital mortality and frailty at discharge for underweight, overweight, and obese patients relative to normal BMI was 1.25 ( p = 0.004), 0.58 ( p < 0.001), and 0.70 ( p = 0.047) and 1.53 ( p < 0.001), 0.80 ( p = 0.095), and 0.60 ( p = 0.022), respectively.

CONCLUSIONS

Obesity is associated with higher hospital survival and functional outcomes at discharge in Asian patients with sepsis.

A comparison of analytic approaches for investigating the obesity paradox in kidney cancer

PURPOSE

Body mass index (BMI) and kidney cancer mortality are inconsistently associated in the scientific literature. To understand how study design affects results, we contrasted associations between pre-diagnosis BMI and mortality under different analytic scenarios in a large, population-based prospective cohort study.

METHODS

Using data from the NIH-AARP Diet and Health Study (1995-2011), we constructed two cohorts: a "full at-risk" cohort with no kidney cancer history at baseline (n = 252,845) and an "incident cancer" subset who developed kidney cancer during follow-up (n = 1,652). Cox Proportional Hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) between pre-diagnosis BMI and mortality for different outcomes (all-cause and cancer-specific mortality), in the different cohorts (full at-risk vs. incident cancer cohort), and with different covariates (minimally vs. fully adjusted). For the incident cancer cohort, we also examined time to mortality using different timescales: from enrollment or diagnosis.

RESULTS

In the full at-risk study population, higher pre-diagnosis BMI was associated with greater cancer-specific mortality in fully adjusted multivariable models, particularly for obese participants [HR, (95% CI): 1.76, (1.38-2.25)]. This association was less pronounced in the incident cancer cohort [1.50, (1.09-2.07)]. BMI was not strongly associated with all-cause mortality in either cohort in fully adjusted models [full cohort: 1.03, (1.01, 1.06); incident cancer cohort: 1.20, (0.97, 1.48)].

CONCLUSIONS

Populations characterized by high adult BMI will likely experience greater population burdens of mortality from kidney cancer, partially because of higher rates of kidney cancer diagnosis. Questions regarding overall mortality burden and post-diagnosis cancer survivorship are distinct and require different study designs.

Anthropometric measures and adverse outcomes in heart failure with reduced ejection fraction: revisiting the obesity paradox

AIMS

Although body mass index (BMI) is the most commonly used anthropometric measure, newer indices such as the waist-to-height ratio, better reflect the location and amount of ectopic fat, as well as the weight of the skeleton, and may be more useful.

METHODS AND RESULTS

The prognostic value of several newer anthropometric indices was compared with that of BMI in patients with heart failure (HF) and reduced ejection fraction (HFrEF) enrolled in prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure. The primary outcome was HF hospitalization or cardiovascular death. The association between anthropometric indices and outcomes were comprehensively adjusted for other prognostic variables, including natriuretic peptides. An 'obesity-survival paradox' related to lower mortality risk in those with BMI ≥25 kg/m2 (compared with normal weight) was identified but this was eliminated by adjustment for other prognostic variables. This paradox was less evident for waist-to-height ratio (as an exemplar of indices not incorporating weight) and eliminated by adjustment: the adjusted hazard ratio (aHR) for all-cause mortality, for quintile 5 vs. quintile 1, was 1.10 [95% confidence interval (CI) 0.87-1.39]. However, both BMI and waist-to-height ratio showed that greater adiposity was associated with a higher risk of the primary outcome and HF hospitalization; this was more evident for waist-to-height ratio and persisted after adjustment e.g. the aHR for HF hospitalization for quintile 5 vs. quintile 1 of waist-to-height ratio was 1.39 (95% CI 1.06-1.81).

CONCLUSION

In patients with HFrEF, alternative anthropometric measurements showed no evidence for an 'obesity-survival paradox'. Newer indices that do not incorporate weight showed that greater adiposity was clearly associated with a higher risk of HF hospitalization.

The obesity paradox in ST-segment elevation myocardial infarction patients: A meta-analysis

OBJECTIVE

The aim of this study was to investigate whether there was a difference in survival after initial percutaneous coronary intervention (PCI) among ST-segment elevation myocardial infarction (STEMI) patients with different body mass index (BMI).

METHODS

Literature retrieval was conducted on PubMed, Web of Science, Embase, CNKI, and Wanfang databases to obtain the published studies on the survival of STEMI patients with different BMI after initial PCI from the establishment of the database to 2022. All statistical analyses were performed using STATA16.0.

RESULTS

Two hundred thirty-nine studies were retrieved, and 12 studies were eventually included. Meta-analysis showed that overweight patients [OR = 0.66, 95% CI (0.58, 0.76), p < .001] and obese patients [OR = 0.60, 95% CI (0.51, 0.72), p < .001] had lower in-hospital mortality than healthy-weight patients. Overweight patients [OR = 0.66, 95% CI (0.58, 0.74), p < .001] and obese patients [OR = 0.62, 95% CI (0.53, 0.72), p < .001] had lower short-term mortality than healthy-weight patients. In addition, overweight patients [OR = 0.63, 95% CI (0.58, 0.69), p < .001] and obese patients [OR = 0.59, 95% CI (0.52, 0.66), p < .001] also had lower long-term mortality than healthy-weight patients. There was no significant difference in in-hospital mortality [OR = 1.06, 95% CI (0.89, 1.27), p > .05], short-term mortality [OR = 1.04, 95% CI (0.89, 1.22), p > .05], and long-term mortality [OR = 1.07, 95% CI (0.95, 1.20), p > .05] between overweight and obese patients.

CONCLUSION

This meta-analysis confirmed an obesity paradox in STEMI patients following PCI. The obesity paradox exists in in-hospital, short-term, and long-term conditions.