The obesity paradox: is it really a paradox? Hypertension

Risk of Cardiovascular Diseases Among Different Metabolic Obesity Phenotypes: A Prospective Observational Study

Objectives: Various diseases are associated with obesity and metabolism. We sought to investigate the risk of cardiovascular disease (CVD) in diverse metabolic obesity phenotypes. Methods and Results: A prospective observational study of 1517 participants ≥25 years of age without CVD at baseline was conducted. Participants were categorized into four groups based on the condition of central obesity and metabolic health status: metabolically healthy normal weight, metabolically healthy obesity (MHO), metabolically unhealthy normal weight, and metabolically unhealthy obese (MUO). A multivariate Cox regression analysis was used to analyze the relationship between different obesity phenotypes and CVD. During 14830.49 person-years of follow-up, there were 244 incident cases of CVD. Of the 1517 participants, 72 (4.75%) and 812 (53.53%) were classified as having MHO and MUO, respectively. MHO and MUO had a tendency toward a higher risk of CVD [adjusted hazard ratios (HRs) = 1.49, 95% confidence interval (CI): 1.11-2.02 and HR = 1.25, 95% CI: 1.00-1.55, respectively] based on the waist circumference criterion. Conclusion: MHO and MUO can increase the risk of CVD.

Inflammaging and body composition: New insights in diabetic and hypertensive elderly men

Age-related changes in the body's physiological responses play a critical role in systemic arterial hypertension (SAH) and type 2 Diabetes mellitus (T2DM). SAH and T2DM have clinically silent low-grade inflammation as a common risk factor. This inflammation has a relevant element, the excess of fatty tissue. In this scenario, little is known about how inflammatory markers interact with each other. Therefore, this work evaluated the interplay among anthropometric, biochemical, and inflammatory markers in the elderly with SAH and T2DM. Men aged 60-80 years old with SAH and T2DM were classified by body mass index (BMI) as eutrophic elderly (EE, 24 individuals) or overweight elderly (OE, 25 individuals). Body composition analysis was performed using bioimpedance. Blood samples were collected to perform inflammatory and biochemical evaluations. The cytokines IL-17A, IL-1β, IFN-y, TNF-α, and IL-10, were evaluated by ELISA. Triglycerides, total and fractions of cholesterol, and glucose were measured by spectrophotometry. Overweight elderly men had a higher glycemic index and an increase in most anthropometric markers, as well as higher means for all pro-inflammatory cytokines analyzed (IL-17A, IL-1β, IFN-y, and TNF-α) in comparison to their eutrophic elderly counterparts. However, there was a decrease in IL-10 anti-inflammatory cytokine and IL-10/IL-17A ratio compared to their eutrophic elderly counterparts. Although overweight elderly men have worsening inflammatory parameters, the magnitude of their correlations with anthropometric and biochemical parameters becomes less evident. The Bayesian networks highlight that in the eutrophic elderly, IL-17A and TNF-α are the cytokines most associated with interactions, and most of these interactions occur with biochemical parameters. It is worth highlighting the role of IFN-y in overweight elderly men. This cytokine influences IL-10 and TNF-α production, contributing to the inflammatory profile exacerbated in this group.

Body mass index change in relation to longitudinal systolic blood pressure: An age- and sex-matched and repeated measures study

BACKGROUND AND AIMS

The positive association between mean systolic blood pressure (SBP) and body mass index (BMI) diminished or reversed over the past four decades. The primary aim of this study was to evaluate effects of BMI change on longitudinal SBP.

METHODS AND RESULTS

A total of 3638 participants who had annual health examination from 2015 to 2019 were included and matched by age and sex according to BMI levels. BMI and SBP were measured annually and their association were assessed by a linear mixed-effects regression model. The normal weight participants had a sustained weight gain as well as SBP increase during the study period (all P_trend <0.001). The obese participants had a sustained weight loss but SBP did not decrease simultaneously. If BMI change was considered, the obese participants with BMI loss had a significant decrease of SBP during the study period (P_trend = 0.0012). Mixed-effects models showed that weight gain was more influential on longitudinal SBP in the normal weight participants and weight loss was in the obese participants. The obese group with BMI loss had a decrease of SBP by 5.01 mmHg (95% confidence interval: 2.56 mmHg, 7.46 mmHg) compared to their counterparts with BMI maintenance from 2015 to 2019.

CONCLUSIONS

The effect of weight change on longitudinal SBP was varied among BMI groups. With the increase of baseline BMI level, the positive effect of weight loss on SBP became greater and the negative effect of weight gain on SBP were attenuated.

“The obesity paradox” in patients with atrial fibrillation according to the results of the REKUR-AF study

Introduction: to evaluate the effect of excess body weight (EBW) and obesity on the survival of patients with atrial fibrillation (AF) in the REKUR-AF study.

Materials and methods: A subanalysis of patients with AF included in the REKUR-AF (382 people) study was performed. Survival rates were analyzed in three patient groups: patients with normal body mass index (BMI), EBW and obesity. Then the nature and significance of the influence of the studied factor on the prognosis in patients with AF were assessed.

Results and discussion: Patients with AF and normal BMI were significantly older than those with obesity and EBW (p&lt;0.001 and p=0.021, respectively). Among obese patients, hypertension was significantly (p=0.0015) more common (93.9%) compared to the group of patients with a normal BMI level (80.5%). The frequency of type 2 diabetes in obese patients prevailed over the same indicator in the groups of people with normal BMI and EBW (p=0.007 and p=0.020, respectively).

The analysis of the survival rate of patients with AF depending on the BMI level showed that this factor had a significant impact (p=0.013) on the prognosis. The group of individuals with a normal BMI level had a significantly lower survival rate than the cohort of patients with EBW (p=0.011) and OB (p=0.025). The final model for Cox regression analysis (χ2=53.06, p&lt;0.001) included the following factors: age, form of AF, BMI, presence/absence of type 2 diabetes, presence/absence of previous hospitalizations, presence/absence of hypertension, and presence/absence of oral anticoagulant (OAC) intake.

Conclusion: The obtained results do not make it possible to unambiguously interpret obesity as a predictor of a positive outcome in this category of individuals.

Obesity paradox and heart failure

BACKGROUND

There is scientific consensus that obesity increases the risk of cardiovascular diseases (CVD), including heart failure (HF). However, in CVD, many studies observed greater survival in overweight or class 1 obesity individuals. This counterintuitive observation was termed "obesity paradox" (OP).

OBJECTIVE AND METHODS

This article is a narrative overview of the relationship between OP and CVD, particularly HF. The sources used were MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from 2001 to 31 May 2020, exception for a 1983 work of historical importance. Studies reporting association and prognostic impact of obesity in HF and the impact of body composition on cardiac structure and myocardial function in obesity were also included in this review. In addition, we examined references from the retrieved articles and explored several related websites. Ultimately, we chose 79 relevant documents. Fifty-three were specifically focused on OP and HF.

RESULTS

In this review, we made a summary of the evidence coming from a series of studies investigating OP. Many of these studies do not take into consideration or underestimate some of the more important morpho-functional variables of patients suffering from HF: among these, body composition and visceral adiposity, sarcopenic obesity, muscle fitness (MF), and cardiorespiratory fitness (CRF). A high body mass index (BMI) represents a risk factor for HF, but it also seems to exert a protective effect under certain circumstances. Fat distribution, lean mass, and cardio fitness could play an essential role in determining the observed differences in the HF population.

CONCLUSION

BMI does not distinguish between the metabolically healthy and metabolically unhealthy obesity. The obesity impact on morbidity and premature mortality can be underestimated and, therefore, may lead to incorrect clinical courses.

LEVEL OF EVIDENCE

Level V, Narrative review.

Impact of Obstructive Sleep Apnea on In-Hospital Outcomes of Patients with Non-ST Elevation Myocardial Infarction

Background: Obstructive sleep apnea (OSA) is one of the most common breathing disorders. There are uncertainties about its impact on the in-hospital outcomes of patients who suffer acute coronary syndromes. We studied the largest publicly available all-payer inpatient healthcare database in the United States (National Inpatient Sample) to determine the effects of obstructive sleep apnea on the in-hospital outcomes of patients admitted with non-ST elevation myocardial infarction (NSTEMI). Methods: All adult patients (age ≥ 18) admitted primarily for NSTEMI between September 2010 and September 2015 were identified in the National Inpatient Sample. They were then categorized into those with OSA and those without OSA. The main outcome was in-hospital mortality. Propensity scoring and logistic regression models were created to determine the outcomes. Results: There were 1,984,432 patients with NSTEMI (weighted estimates), 123,551 (6.23%) of who had diagnosed OSA while 1,860,881 (93.77%) did not. In-hospital mortality was significantly lower in the OSA group [2.61% vs. 3.53%, adjusted odd ratio (aOR) 0.73 and confidence interval (CI) (0.66–0.81)]. Patients with OSA were also less likely to require coronary artery bypass surgery: 13.85% and 12.77% (p-value 0.0003). The patients with OSA had higher mean hospital costs compared to the patients who did not have OSA: $17,326 vs. $16,984, adjusted mean ratio (aMR) 1.02; CI (1.01–1.02). Conclusion: In-hospital mortality was lower in NSTEMI patients with diagnosed OSA compared to patients without diagnosed OSA. This appears to contrast with the widely recognized adverse effects of OSA on the cardiovascular system.

Digital Predictors of Morbidity, Hospitalization, and Mortality Among Older Adults: A Systematic Review and Meta-Analysis

The widespread adoption of digital health technologies such as smartphone-based mobile applications, wearable activity trackers and Internet of Things systems has rapidly enabled new opportunities for predictive health monitoring. Leveraging digital health tools to track parameters relevant to human health is particularly important for the older segments of the population as old age is associated with multimorbidity and higher care needs. In order to assess the potential of these digital health technologies to improve health outcomes, it is paramount to investigate which digitally measurable parameters can effectively improve health outcomes among the elderly population. Currently, there is a lack of systematic evidence on this topic due to the inherent heterogeneity of the digital health domain and the lack of clinical validation of both novel prototypes and marketed devices. For this reason, the aim of the current study is to synthesize and systematically analyse which digitally measurable data may be effectively collected through digital health devices to improve health outcomes for older people. Using a modified PICO process and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework, we provide the results of a systematic review and subsequent meta-analysis of digitally measurable predictors of morbidity, hospitalization, and mortality among older adults aged 65 or older. These findings can inform both technology developers and clinicians involved in the design, development and clinical implementation of digital health technologies for elderly citizens.

Obesity paradox and aging

BACKGROUND

In association with the rapid lengthening of life expectancy and the ever-rising prevalence of obesity, many studies explored in the elderly the phenomenon usually defined as the obesity paradox.

OBJECTIVE AND METHODS

This article is a narrative overview of seventy-two papers (1999-2019) that investigated the obesity paradox during the aging process. Twenty-nine documents are examined more in detail.

RESULTS

The majority of studies suggesting the existence of an obesity paradox have evaluated just BMI as an index of obesity. Some aspects are often not assessed or are underestimated, in particular body composition and visceral adiposity, sarcopenic obesity, and cardio fitness. Many studies support that central fat and relative loss of fat-free mass may become relatively more important than BMI in determining the health risk associated with obesity in older ages.

CONCLUSION

Inaccurate assessments may lead to a systematic underestimation of the impact of obesity on morbidity and premature mortality and, consequently, to clinical behaviors that are not respectful of the health of elderly patients. Knowledge of the changes in body composition and fat distribution will help to better understand the relationship between obesity, morbidity, and mortality in the elderly.

LEVEL OF EVIDENCE

Level V, narrative overview.

Effect of Body Mass Index on the Prognosis of Liver Cirrhosis

Objective: At present, the association of body mass index (BMI) with the prognosis of liver cirrhosis is controversial. Our retrospective study aimed to evaluate the impact of BMI on the outcome of liver cirrhosis. Methods: In the first part, long-term death was evaluated in 436 patients with cirrhosis and without malignancy from our prospectively established single-center database. In the second part, in-hospital death was evaluated in 379 patients with cirrhosis and with acute gastrointestinal bleeding (AGIB) from our retrospective multicenter study. BMI was calculated and categorized as underweight (BMI <18.5 kg/m²), normal weight (18.5 ≤ BMI < 23.0 kg/m²), and overweight/obese (BMI ≥ 23.0 kg/m²). Results: In the first part, Kaplan-Meier curve analyses demonstrated a significantly higher cumulative survival rate in the overweight/obese group than the normal weight group (p = 0.047). Cox regression analyses demonstrated that overweight/obesity was significantly associated with decreased long-term mortality compared with the normal weight group [hazard ratio (HR) = 0.635; 95% CI: 0.405-0.998; p = 0.049] but not an independent predictor after adjusting for age, gender, and Child-Pugh score (HR = 0.758; 95%CI: 0.479-1.199; p = 0.236). In the second part, Kaplan-Meier curve analyses demonstrated no significant difference in the cumulative survival rate between the overweight/obese and the normal weight groups (p = 0.094). Cox regression analyses also demonstrated that overweight/obesity was not significantly associated with in-hospital mortality compared with normal weight group (HR = 0.349; 95%CI: 0.096-1.269; p = 0.110). In both of the two parts, the Kaplan-Meier curve analyses demonstrated no significant difference in the cumulative survival rate between underweight and normal weight groups. Conclusion: Overweight/obesity is modestly associated with long-term survival in patients with cirrhosis but not an independent prognostic predictor. There is little effect of overweight/obesity on the short-term survival of patients with cirrhosis and with AGIB.

[The «obesity paradox» and its degree of proof]

The article gives a critical assessment of the so-called obesity paradox. Methodological errors that occur in the organization of studies that studied the obesity paradox and the formation of comparison groups are highlighted. There are also examples of the disappearance of the obesity paradox when taking into account additional risk factors. The organization of prospective studies or more careful consideration of all currently known risk factors for cardiovascular diseases (CVD) will significantly improve the results of the study of the effect of overweight and obesity on mortality in patients with CVD. Thus, despite the biological possibility of the existence of a positive effect of adipose tissue in CVD, the presence of a large number of errors identified in the analysis of the work of researchers obesity paradox require to reconsider the existence of this phenomenon, it should be taken into account the possibility that the obesity paradox may be a consequence of improper design studies to investigate this phenomenon.

Factors Associated with Inpatient Mortality after Intracerebral Hemorrhage: Updated Information from the United States Nationwide Inpatient Sample

BACKGROUND

To use a nationwide database of hospital admissions to assess for trends in inpatient mortality from acute spontaneous intracerebral hemorrhage as well as associated potentially contributing factors.

METHODS

Adults with intracerebral hemorrhage in the US National Inpatient Sample database from 2012 to 2015 were included in this study. We assessed for mortality rate as well as potential impact of various comorbidities and demographic factors such as ethnicity and median house hold income on inpatient mortality rate.

RESULTS

A total of 47,700 patients were identified with a mean age of 68 years. The overall mortality rate was 24%. Hypertension was the commonest comorbidity (84%) followed by diabetes mellitus (28%). Positive associated factors for mortality rate were coagulopathy (OR 1.28, 95% CI 1.19-1.38, P < .001), female gender (OR 1.12, 95% CI 1.08-1.17, P < .001), and congestive heart failure (OR 1.16, 95% CI 1.08-1.24, P < .001). Age greater than 75 was also associated with higher mortality (P < .001). Factors associated with reduced mortality were hypertension (OR .76, 95% CI .72-0.81, P < .001), hypothyroidism (OR .87, 95% CI .81-.93, P < .001) and obesity (OR .64, 95% CI .59-.69, P < .001).

CONCLUSIONS

The inpatient mortality of 24% represents a decline when compared to previous years. Attention to the associated factors with mortality, that we report, could have some potential impact on management. Of interest, we found support for obesity paradox in which obesity may have an actual salutary effect on vascular disease outcome. Our observed paradoxical effects, not only for obesity, but also hypertension and hypothyroidism, warrant further study.

Effects of Bariatric Surgery on Cardiovascular Disease: A Concise Update of Recent Advances

Patients with obesity often have multiple cardiovascular comorbidities as obesity is an established risk factor for various cardiovascular diseases (CVDs)—e. g., heart failure (HF), coronary artery disease (CAD), hypertension, dysrhythmia, and venous thromboembolism. In the United States, obesity is the nationwide public health issue of the day with the prevalence exceeding 30%. It has become a substantial health and financial burden to the society and national healthcare system; the direct cost accounted for 150 billion US dollars in 2014. Lifestyle interventions have been shown to be successful in the short term, however their long-term results are still equivocal likely due to modest weight reduction and high recurrence rates. For instance, the mean weight reduction in a randomized controlled trial of patients with type 2 diabetes mellitus (DM) and either overweight or obesity was 6.0% in the intensive lifestyle modification arm and 3.5% in the control arm. On the contrary, bariatric surgery is known to be the most effective in achieving substantial and long-term weight loss and can prevent the development of CVD risk factors such as DM, hypertension, and dyslipidemia. Bariatric surgery induces prompt weight loss within a few months which lasts for at least 12–18 months, with mean weight loss of ~35% (~70% loss of excess weight), lowering the risk of all-cause mortality, myocardial infarction, and stroke. Furthermore, recent studies demonstrated that bariatric surgery contributed to the reduction of acute care use for HF, CAD, and hypertension. On the other hand, it was reported that bariatric surgery may worsen the control of certain types of CVD (e.g., dysrhythmia), especially in the early postoperative period. Additionally, the notion that being overweight or obese could contribute to higher survival rate in certain populations (e.g., patients with HF)—also known as “obesity paradox”—has been repetitively documented in the past, while most recent investigations suggested that the observed paradox may be attributable to confounding factors including pre-existing comorbidities. Considering the aforementioned advances in the field, this paper reviews a series of recent studies with regard to the short-term and long-term effects of bariatric surgery on various types of CVDs.

Diabetes, but Not Hypertension and Obesity, Is Associated with Postoperative Cognitive Dysfunction

BACKGROUND/AIMS

Older people undergoing surgery are at risk of developing postoperative cognitive dysfunction (POCD), but little is known of risk factors predisposing patients to POCD. Our objective was to estimate the risk of POCD associated with exposure to preoperative diabetes, hypertension, and obesity.

METHODS

Original data from 3 randomised controlled trials (OCTOPUS, DECS, SuDoCo) were obtained for secondary analysis on diabetes, hypertension, baseline blood pressure, obesity (BMI ≥30 kg/m2), and BMI as risk factors for POCD in multiple logistic regression models. Risk estimates were pooled across the 3 studies.

RESULTS

Analyses totalled 1,034 patients. POCD occurred in 5.2% of patients in DECS, in 9.4% in SuDoCo, and in 32.1% of patients in OCTOPUS. After adjustment for age, sex, surgery type, randomisation, obesity, and hypertension, diabetes was associated with a 1.84-fold increased risk of POCD (OR 1.84; 95% CI 1.14, 2.97; p = 0.01). Obesity, BMI, hypertension, and baseline blood pressure were each not associated with POCD in fully adjusted models (all p > 0.05).

CONCLUSION

Diabetes, but not obesity or hypertension, is associated with increased POCD risk. Consideration of diabetes status may be helpful for risk assessment of surgical patients.

Philosophical determinants of obesity as a disease

Is obesity a disease? Much ink has been spilled over this debate and for good reasons. The global prevalence of obesity has more than doubled since the 1980s and is now of pandemic proportions. Whether obesity is a disease has consequences for what kind of treatments are appropriate, as well as how we ought to allocate funding and access to healthcare resources. In most cases, there is no dispute over the medical facts, yet disagreement persists. This is because whether obesity is a disease is not determined by medical facts alone; the issue is, in part, conceptual. Science relies on careful argumentation and conceptual analysis as part of its armamentarium. In this review, we will examine the two concepts of disease most often employed in the philosophy of medicine: the naturalistic and constructivist. We will argue that, whichever definition of a disease is used, obesity fits the criteria for disease definition. Those seeking to meet the challenge of managing obesity will, therefore, need to embrace chronic disease models of care suited to addressing the lifelong challenge posed by this disease and its associated complications.

Effect of Gamma-Oryzanol as Therapeutic Agent to Prevent Cardiorenal Metabolic Syndrome in Animals Submitted to High Sugar-Fat Diet

BACKGROUND

The high consumption of fat and sugar contributes to the development of obesity and co-morbidities, such as diabetes, and cardiovascular and kidney diseases. Different strategies have been used to prevent these diseases associated with obesity, such as changes in eating habits and/or the addition of dietary components with anti-inflammatory and anti-oxidant properties, such as gamma-oryzanol (γOz) present mainly in bran layers and rice germ.

METHODS

Animals were randomly divided into four experimental groups and fed ad libitum for 20 weeks with control diet (C, n = 8), control diet + γOz (C + γOz, n = 8), high-sugar and high-fat diet (HSF, n = 8), and high-sugar and high-fat diet + γOz (HSF + γOz, n = 8). HSF groups also received water + sucrose (25%). The dose of γOz was added to diets to reach 0.5% of final concentration (w/w). Evaluation in animals included food and caloric intake, body weight, plasma glucose, insulin, triglycerides, uric acid, HOMA-IR, glomerular filtration rate, protein/creatinine ratio, systolic blood pressure, and Doppler echocardiographic.

RESULTS

Animals that consumed the HSF diet had weight gain compared to group C, increased insulin, HOMA, glucose and triglycerides, there were also atrial and ventricular structural alterations, deterioration of systolic and diastolic function, decreased glomerular filtration rate, and proteinuria. Gamma-oryzanol is significantly protective against effects on body weight, hypertriglyceridemia, renal damage, and against structural and functional alteration of the heart.

CONCLUSION

Gamma-oryzanol shows potential as a therapeutic to prevent Cardiorenal Metabolic Syndrome.