How reliable is BMI? Bioimpedance analysis of body composition in underweight, normal weight, overweight, and obese women

Advancing Nutritional Care Through Bioelectrical Impedance Analysis in Critical Patients

Nutritional support in critically ill patients has been acknowledged as a pillar of ICU care, playing a pivotal role in preserving muscle mass, supporting immune function, and promoting recovery during and after critical illness. Providing effective nutritional support requires adapting it to the patient's diagnosis, unique characteristics, and metabolic state to minimize the risks of overfeeding or underfeeding while mitigating muscle loss. This level of care requires a comprehensive nutritional assessment and the establishment of a nutrition-focused protocol. Regular, consistent and detailed nutritional evaluation can influence both therapeutic decisions and clinical interventions, thus ensuring that the specific needs of critically ill patients are met from the acute phase through their entire recovery process. Bioelectrical impedance analysis (BIA) is increasingly recognized as a valuable tool for enhancing nutritional care in critically ill patients. By delivering precise, real-time insights into key aspects of body composition, BIA is thought to provide clinicians with a more comprehensive understanding of the complex physiological changes that occur during critical illness. This narrative review highlights the potential of BIA in offering these precise assessments, facilitating the development of more accurate and personalized nutritional strategies for critically ill patients. If BIA can reliably assess dynamic shifts in hydration and tissue integrity, it holds the promise of further advancing individualized care and optimizing clinical outcomes in this vulnerable population.

Phase angle as a potential tool to evaluate chronic inflammatory state and predict quality of life deterioration in women with breast cancer and obesity: A narrative review

The interaction between lifestyle--defined more specifically in health care as the personal exposome--and its implications on obesity and breast cancer development highlights the critical role of body composition and inflammation in these patients. There is clear evidence that the personal and internal exposome triggers biochemical, inflammatory, and metabolic reprogramming, which might favor ectopic lipid accumulation within the body, such as muscles. Additionally, the presence of excessive adipose tissue exacerbates these alterations in the internal exposome, resulting in cell damage and modifying body composition. Understanding the nexus between these lifestyle-induced exposome modifications, such as inflammation, and the resultant changes in body composition is crucial to assess the association with breast cancer progression and treatment responses. Various techniques can be used to evaluate body composition; one of those most used currently is bioelectrical impedance analysis. This analysis provides parameters, including phase angle (PhA), by which cellular health and metabolic activity can be assessed. In addition, PhA is a potential indicator of nutritional status and disease prognosis, as it has been linked to survival and quality of life in patients with cancer. Therefore, PhA might be used in daily oncology practice to implement an accurate nutritional intervention, reducing side effects and complications of oncology management, and improving quality of life during treatment and survival, even in patients with breast cancer with obesity or overweight. The aim of this review is to analyze the existing information on the current application of PhA in patients with breast cancer and its potential use as a tool to assess inflammatory response, identify malnutrition, and predict the deterioration of quality of life so that it could be proposed as an early indicator for nutritional interventions in this group of patients.

Bioelectrical impedance and lung function-associations with gender and central obesity: results of the EpiHealth study

BACKGROUND

Obesity is a major public health concern associated with various health problems, including respiratory impairment. Bioelectrical impedance (BIA) is used in health screening to assess body fat. However, there is no consensus in healthcare on how body fat should be assessed in relation to lung function. In this study, we aimed to investigate how BIA in relation to waist circumference contribute, using data from a large Swedish population study.

METHODS

A total of 17,097 participants (aged 45-75 years) were included in the study. The relationships between fat mass, waist circumference, and lung function were analysed using weighted quantile sum regression.

RESULTS

Increased fat mass was significantly associated with decreased lung function (FEV1, FVC) in both sexes. Also, the influence of trunk fat and waist circumference on FVC and FEV1 differed by sex: in males, waist circumference and trunk fat had nearly equal importance for FVC (variable weights of 0.42 and 0.41), whereas in females, trunk fat was significantly more important (variable weights 0.84 and 0.14). For FEV1, waist circumference was more important in males, while trunk fat was more significant in females (variable weights male 0.68 and 0.28 and 0.23 and 0.77 in female).

CONCLUSIONS

Our results suggest that trunk fat should be considered when assessing the impact of adipose tissue on lung function and should potentially be included in the health controls.

Muscle mass and chronic dizziness: a cross-sectional study of a Korean population

BACKGROUND AND OBJECTIVES

Weight gain is associated with imbalance in older people. In contrast, overweightness or mild obesity is less common in patients with chronic dizziness. This paradox may be, at least in part, related to differences in the body composition indices adopted in the previous studies. This study aimed to determine any association between the predicted body composition and chronic dizziness or imbalance of unknown causes.

METHODS

We measured the lean body mass, body fat mass, and appendicular skeletal mass in 9243 people who participated in the Korean National Health and Nutrition Examination Survey 2019-2021. Sarcopenia was defined according to the Asian Working Group for Sarcopenia's guidelines. Obesity was defined as a body fat percentage of ≥ 25% for men and ≥ 35% for women.

RESULTS

The participants with chronic dizziness had a lower body mass index than those without (p = 0.001). Furthermore, sarcopenia was more common in those with chronic dizziness. In contrast, the degree of obesity was comparable in both groups. Multiple logistic regression analysis showed that sarcopenia was associated with a higher risk of chronic dizziness (odds ratio = 1.6, 95% confidence interval: 1.1-2.5; p = 0.026).

DISCUSSION

Given the association of sarcopenia with chronic dizziness or imbalance, muscle mass may play a role in maintaining balance and stability. Physical exercise could be recommended to increase muscle mass in patients with chronic dizziness/imbalance and sarcopenia. Additional research is required to establish a causal relationship between chronic dizziness and sarcopenia.

Patient-Level and Center-Level Factors Associated with Required Predonation Weight Loss among Obese Living Kidney Donors

Key Points

Among obese living kidney donors, year of donation, preoperative body mass index, hypertension, and center percent of living kidney donor transplants were associated with required predonation weight loss. There were no significant differences in the likelihood of predonation weight loss requirement by race, sex, or age or by markers of preoperative metabolic dysfunction.

Background

The proportion of overweight/mildly obese living kidney donors (OLKDs) has increased in the past few decades, with significant center variation in the body mass index (BMI) of LKDs. The purpose of this study was to examine factors associated with required predonation weight loss among OLKDs (BMI, ≥30 kg/m2).

Methods

This retrospective cohort study surveyed 1097 OLKDs (1979–2020) (mean BMI, 33 kg/m2) about their donation experience. Bivariate analyses compared donor demographic and center characteristics by whether the donor reported predonation weight loss requirement. Generalized estimating equations with logit link were used to estimate marginal effects of patient-level and center-level factors. Multiple imputation using chained equations was implemented to account for missing values.

Results

Of 1097 OLKDs surveyed, 340 (31.0%) reported predonation weight loss requirement. Donors with a predonation weight loss requirement had slightly higher predonation BMIs and donated in more recent years at centers performing a lower percentage of living donor nephrectomies and with a lower median BMI. In multivariable logistic regression analysis, we observed transplant year (odds ratio [OR], 1.04 per year donation; 95% confidence interval [CI], 1.01 to 1.07; P = 0.005), preoperative BMI (OR, 1.16; 95% CI, 1.05 to 1.28; P < 0.01), preoperative hypertension (OR, 1.61; 95% CI, 1.08 to 2.40; P = 0.02), and center percentage of living donor kidney transplants (OR, 0.99; 95% CI, 0.98 to 1.00; P = 0.02) as significantly associated with a predonation weight loss requirement. The study found no differences in the likelihood of predonation weight loss requirement by race, sex, age, preoperative creatinine, preoperative metabolic dysfunction, or center-level median BMI of living donors.

Conclusions

These results suggest that both center-level and patient-level factors influence whether OLKDs are required to lose weight before donation. Future study is needed to determine whether predonation weight loss is associated with improved long-term postdonation outcomes.

Obesity Is Associated with Immunometabolic Changes in Adipose Tissue That May Drive Treatment Resistance in Breast Cancer: Immune-Metabolic Reprogramming and Novel Therapeutic Strategies

White adipose tissue (WAT) represents an endocrinologically and immunologically active tissue whose primary role is energy storage and homeostasis. Breast WAT is involved in the secretion of hormones and proinflammatory molecules that are associated with breast cancer development and progression. The role of adiposity and systemic inflammation in immune responses and resistance to anti-cancer treatment in breast cancer (BC) patients is still not clear. Metformin has demonstrated antitumorigenic properties both in pre-clinical and clinical studies. Nevertheless, its immunomodulating properties in BC are largely unknown. This review aims to evaluate the emerging evidence on the crosstalk between adiposity and the immune-tumour microenvironment in BC, its progression and treatment resistance, and the immunometabolic role of metformin in BC. Adiposity, and by extension subclinical inflammation, are associated with metabolic dysfunction and changes in the immune-tumour microenvironment in BC. In oestrogen receptor positive (ER+) breast tumours, it is proposed that these changes are mediated via a paracrine interaction between macrophages and preadipocytes, leading to elevated aromatase expression and secretion of pro-inflammatory cytokines and adipokines in the breast tissue in patients who are obese or overweight. In HER2+ breast tumours, WAT inflammation has been shown to be associated with resistance to trastuzumab mediated via MAPK or PI3K pathways. Furthermore, adipose tissue in patients with obesity is associated with upregulation of immune checkpoints on T-cells that is partially mediated via immunomodulatory effects of leptin and has been paradoxically associated with improved responses to immunotherapy in several cancers. Metformin may play a role in the metabolic reprogramming of tumour-infiltrating immune cells that are dysregulated by systemic inflammation. In conclusion, evidence suggests that body composition and metabolic status are associated with patient outcomes. To optimise patient stratification and personalisation of treatment, prospective studies are required to evaluate the role of body composition and metabolic parameters in metabolic immune reprogramming with and without immunotherapy in patients with BC.

Normative reference data for body composition in healthy indigenous populations on the Qinghai-Tibet Plateau

Body composition represents an important aspect of physical fitness and has received increasing attention in recent years. The present study was designed and conducted to provide reference values for age-, sex-, and altitude-specific body composition for healthy indigenous Tibetan adults living on the Qinghai-Tibet Plateau, which has not yet been studied. A cross-sectional survey was conducted among 2,356 healthy Tibetan adults (1,433 females and 923 males) living on the Qinghai-Tibet Plateau for generations. The body composition of the participants was measured by bioelectrical impedance analysis (BIA). The measurements included weight, basal metabolic rate (BMR), fat-free mass (FFM), skeletal muscle mass (SMM), protein mass (PM), bone mass (BM), fat mass (FM), percentage of body fat (PBF), subcutaneous fat mass (SFM), visceral fat mass (VFM), total body water (TBW), intracellular water (ICW), and extracellular water (ECW). Overall, males had greater FFM, SMM, PM, BM, and water mass, whereas females were high in fat mass. Participants from plains generally had higher body composition values, and PM, BM, FM and body water values decreased with increasing altitude, with the lowest values found in >4,000 m Shigatse. FFM, SMM, PM, and BM tended to decrease with increasing age, whereas fat mass and ECW tended to increase with increasing age. This study provides the first normative reference data of body composition for healthy indigenous individuals on the Qinghai-Tibet Plateau. These datasets are important for future research related to body composition. A considerable decrease in body composition values in > 4,000 m-altitude areas suggested that body composition cutoff values should be established by altitude. Age-, sex-, and altitude-specific alterations in body composition values also inform the prevention and amendment of abnormal body composition changes and resultant health complications.

MUSCLE DEPLETED OBESITY IN INDIVIDUALS SCREENED FOR COLORECTAL CÂNCER

BACKGROUND

Colorectal cancer (CRC) is the third most incident cancer in the world and the second leading cause of cancer death. Significant decreases in incidence and mortality can be achieved by reducing risk factors and adhering to healthy lifestyle recommendations, as well as screening for the disease.

OBJECTIVE

To evaluate the clinical nutritional profile of individuals at medium risk screened for CRC residing in the city of Piranhas/Alagoas.

METHODS

Cross-sectional study conducted from September to October 2020, with individuals at medium risk for CRC, of both sexes and aged between 50 and 70 years old. Participants were screened for CRC with fecal immunochemical testing (FIT) and colonoscopy. Personal, socioeconomic, clinical, lifestyle and nutritional assessment data were collected. The latter was performed using anthropometric data (weight, height, arm circumference and triceps skinfold thickness), body composition (bioimpedance) and physical examination. Descriptive analysis of data frequencies and dichotomization according to the presence or absence of overweight was performed, followed by comparison of means and medians and frequencies by chi-square or Fisher's exact test.

RESULTS

In total, 82 people agreed to undergo the clinical nutritional assessment, most of them female (56.1%; n=46), adults (56.1%; n=46), with a mean age of 59.02 years (±6.30 SD). Pre-cancerous lesions were identified in 54.5% (n=42) of those screened, 52.4% (n=43) were smokers or former smokers, and 65.9% (n=54) did not practice scheduled physical activity. Nutritional assessment showed that 64.6% (n=53) were overweight according to body mass index. On the other hand, the muscle mass, % arm muscle circumference adequacy and body muscle mass (kg) markers showed that 32.9% (n=27) and 47.6% (n=39) of the subjects were muscle depleted, respectively. Above all, overweight participants had, in parallel, lower muscle mass (P<0.05), suggesting sarcopenic obesity in this population.

CONCLUSION

Obesity is one of the main risk factors for CRC; when concomitant with sarcopenia, it favors worse health outcomes. In this context, evidence shows the need to assess muscle composition in people with obesity, especially through other methods of assessing body composition. Our results add to the evidence on the importance of the population being guided about screening and adherence to healthy lifestyle recommendations, especially strategies aimed at weight control and the practice of physical activity.

A Guide to the Postmortem Investigation of Starvation in Adults

ABSTRACT

Starvation is a rare cause of death in developed countries and is a complex multifaceted pathological process. To complicate the forensic investigation of starvation further, many medical conditions independent of starvation may cause wasting. This article provides one of the first comprehensive guides to the postmortem investigation of starvation in adults, with reference tables on organ-specific macroscopic and microscopic features, as well as features for excluding alternative causes of wasting. The eclectic literature on this complex topic is summarized in an accessible and easily referenced format, including mechanisms of death and ancillary postmortem investigations.

Socioeconomic inequality in different phenotypes of childhood obesity and its determinants in Iran: a Blinder-Oaxaca decomposition method

Background

Childhood obesity has become a significant public health issue worldwide. Socioeconomic status is among its key determinants. This study examined the socioeconomic inequality in different phenotypes of childhood obesity at the national level in Iran.

Methods

This national, multistage school cross-sectional study was undertaken in 2015 on 14,400 students aged 7–18 years from urban and rural areas of 30 provinces of Iran. Using principal component analysis, socioeconomic status (SES) was categorized into tertiles. SES inequality in different phenotypes of obesity (i.e., generalized obesity", "abdominal obesity", and combined obesity) was estimated using the concentration index. The determinants of this inequality were assessed by the Blinder-Oaxaca decomposition method.

Results

Overall, 14,274 students completed the study (response rate: 99%). The mean age was 12.28 years, 50.6% were boys, and 71.42% lived in urban areas. The prevalence of generalized obesity and abdominal obesity was 20.8% and 11.3%, respectively. The concentration index for different phenotypes of obesity was positive, indicating that inequality is more common amongst the low SES groups. High SES, being male, living in a rural, and having a positive family history of obesity were associated with general obesity. Moderate physical activity and living in a rural area were associated with abdominal obesity. In addition, living in a rural area, having a high SES, being male, and having a positive family history of obesity were associated with combined obesity.

Conclusion

According to the present study findings, all childhood obesity phenotypes were more prevalent in Iranian children with high SES. Therefore, due to obesity and other diseases, it is essential to implement environmental changes in addition to designing macro-educational programs and prevention strategies.

Increased Body Fat and Organic Acid Anions Production Are Associated with Larger Kidney Size in ADPKD

Background and Objectives: A high body mass index (BMI) is associated with the progression of autosomal dominant polycystic kidney disease (ADPKD). However, body fat (BF), which is another adiposity marker, has not yet been studied. Excessive weight may promote elevation in the endogenous synthesis of organic acid (OA) anions. Accordingly, we aimed to investigate the possible association of the aforementioned markers with kidney volume and renal function in patients with ADPKD. Materials and Methods: We conducted a retrospective cohort study of adult ADPKD outpatients involving clinical, serum, and urinary laboratorial data and body composition assessments retrieved from their medical records. BF was estimated by skinfold thickness (mm) on the non-dominant arm and was considered as normal or high for each sex. Total kidney volume (TKV) and height-adjusted volume (htTKV) were measured by magnetic resonance imaging. The annual estimated glomerular filtration rate (eGFR) slope was analyzed during a median follow-up time of 6 (5.0-7.0) years to calculate rapid progression (decline in renal function ≥2.5 mL/min/year over 5 years). Results: A total of 104 patients were included (41.9 ± 11.9 years old, 38.5% men), with 62.5% of the patients classified as high BF. The High BF group presented higher levels of OA, glycosylated hemoglobin (HbA1c), C-reactive protein (CRP), 24 h urinary sodium (UNa), and htTKV, and lower eGFR than those with a normal BF. In the multivariate linear regression, the associated variables with TKV were high BF, OA and BMI (std. β 0.47, p < 0.05; std. β 0.36, p = 0.001; std. β 0.25, p = 0.01, respectively). In the binary logistic regression, when adjusted for potential confounders, UNa was the only parameter associated with an increased risk of eGFR decline ≥2.5 mL/min/year (OR 1.02, 95% CI 1.01-1.03, p = 0.02). Conclusions: Increased body fat and endogenous production of organic acid anions are associated with larger kidney size in ADPKD but not with a decline in renal function.

Myosteatosis reduces overall survival in patients with digestive system malignancies: a meta-analysis with trial sequential analysis

The impact of myosteatosis on the outcomes of digestive malignancies has gained great attention recently. However, studies on the impact of myosteatosis show inconsistent results. We conducted a meta-analysis to clarify the relationship between myosteatosis and the overall survival of digestive cancer patients. The systematic literature search was conducted on PubMed/MEDLINE, Web of Science, and Embase from inception through March 27, 2021. Meta-analysis was performed using the random-effects model. Out of 3451 studies screened, 47 studies including 21,194 patients passed the screening criteria. The average prevalence of myosteatosis was 46.4%. Patients with myosteatosis had 44% increased mortality risk compared with non-myosteatosis patients (HR: 1.44, 95% CI: 1.33-1.55, P < .05). The predictive value of myosteatosis held regardless of country zone, study design, statistical model, Newcastle-Ottawa Scale (NOS) scores, treatment, sample size, and tumor stage. Nevertheless, the predictive value of myosteatosis was only evident for patients with esophagogastric cancers, cholangiocarcinoma/pancreatic cancers, or colorectal cancers. Overall, the results of this meta-analysis were robust based on sensitivity, subgroup, meta-regression, and trial sequential analyses and suggested that myosteatosis predicted worse overall survival (OS) in digestive malignancies patients.