Bioimpedance phase angle is associated with serum transthyretin but not with prognostic inflammatory and nutritional index during follow-up of women submitted to bariatric surgery

Poor diet quality is associated with biochemical parameters of protein nutritional status after Roux-en-Y gastric bypass

OBJECTIVE

To assess diet quality and its association with body and biochemical parameters in patients who underwent Roux-en-Y gastric bypass (RYGB).

METHODS

Prospective observational study with individuals of both sexes subjected to RYGB. Body composition, biochemical parameters, and diet quality were assessed before and six months after RYGB. Diet quality was assessed by the Healthy Eating Index (HEI). Data were analyzed by the paired t-test or Wilcoxon signed-rank test, with a significance level of 5%. Spearman's correlation and simple linear regression were performed between variables.

RESULTS

The final sample included 34 patients. Their diet was classified as poor before and 6 mo after RYGB. BMI, fat mass, fat-free mass, waist perimeter, serum total protein, transthyretin, alpha-1-acid glycoprotein, and C-reactive protein decreased significantly (P < 0.05). Variations in the HEI score and caloric intake were associated with serum albumin and transthyretin (P < 0.05).

CONCLUSION

Poor diet quality was present before and six months after RYGB, and the study data suggest that poor diet quality is associated to a risk of loss of lean body mass and visceral protein six months after RYGB.

Assessment of phase angle as a novel indicator for sarcopenic obesity according to the ESPEN/EASO criteria in older adults with diabetes mellitus

BACKGROUND

Sarcopenic obesity (SO) is a clinical condition in which sarcopenia and obesity occur together, and is associated with more poor clinical outcomes, increased mortality, and morbidity than sarcopenia. Phase angle (PhA), a parameter derived from bioimpedance analysis (BIA), provides data on cellular health, membrane integrity, and cellular function. This study aimed to evaluate the relationship between SO and PhA among older adults with type 2 diabetes mellitus (DM).

METHODS

We performed a cross-sectional study in a tertiary hospital, and all participants underwent a comprehensive geriatric assessment, the hand-grip strength test (HGST), the chair stand test (CST) for muscle strength evaluation, the 4-meter walking test, and the timed up-and-go (TUG) test for physical performance assessment. The diagnosis of SO was made according to the ESPEN/EASO criteria. The PhA was determined automatically by the BIA using resistance and reactance at 50 kHz for each participant.

RESULTS

A total of 322 participants were included in the study. The mean age of the participants was 72.5 ±5.8, and 203 (63%) of them were female; 63 (19.6%) of them were sarcopenic obese. In multivariable logistic regression analyses, a significant relationship was found when the model was adjusted for age, female gender, MNA-sf scores, HbA1c level, and CCI scores (OR: 0.53, 95%CI: 0.29-0.98, P = 0.04). In ROC analyses, for PhA in predicting SO diagnosis, the AUC was 0.586 (95%CI: 0.505-0.678, P = 0.033). At the cut-off score 4.4, sensitivity was 57.1% and specificity was 61.4%; positive predictive value (PPV) was 26.5%; negative predictive value (NPV) was 85.5%.

CONCLUSIONS

The study identified a significant relationship between SO and PhA among older adults with type 2 DM. However, larger prospective studies are needed to confirm the potential utility of PhA as a biomarker for SO.

Variations in phase angle and handgrip strength in patients undergoing cardiac surgery: Prospective cohort study

BACKGROUND

Bioimpedance phase angle (PA) is a measure of cell membrane integrity, whereas handgrip strength (HGS) is an evaluation of functional capacity. Although both are related to the prognosis of patients undergoing cardiac surgery, their changes over time are less known. This study followed variations in PA and HGS for 1 year in these patients, determining associations with clinical outcomes.

METHODS

This prospective cohort study included 272 cardiac surgery patients. PA and HGS were measured at six predetermined times. The evaluated outcomes were surgery type; bleeding; time of surgery, cardiopulmonary bypass, aortic cross-clamp, and mechanical ventilation; postoperative (PO) length of stay (LOS) in the intensive care unit (ICU) and hospital; and infections, hospital readmission, reoperation, and mortality.

RESULTS

There were reductions in PA and HGS values after surgery, with total recovery beginning at 6 months for PA and 3 months for HGS. In the PA area under the curve (AUC), age, combined surgery, and sex (β = -9.66, P < 0.001; β = -252.85, P = 0.005; β = -216.56, P < 0.001, respectively) were predictors for PA-AUC reduction. Stratified by sex, age (β = -93.54, P < 0.001) and PO LOS (β = -46.91, P = 0.003) were predictors for HGS-AUC reduction in women, but only age was a predictor in men (β = -77.02, P = 0.010). PA and HGS had an effect in hospital LOS and ICU LOS.

CONCLUSION

Age, combined surgery, and female sex were predictors of reduced PA-AUC, whereas reduced HGS-AUC was predicted by age in both sexes and PO hospital LOS in women, which suggests that these factors could interfere in prognosis.

Phase angle of bioimpedance as a marker of inflammation in cardiovascular diseases: A systematic review

OBJECTIVE

The aim of this systematic review was to investigate whether phase angle (PhA) of bioelectrical impedance is associated with inflammatory markers in cardiovascular diseases (CVDs).

METHODS

A search was performed in the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American Caribbean Health Sciences Literature (LILACS), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science and Scopus; and in the gray literature up to January 2022. Studies with individuals with CVDs were included, to evaluate the association between PhA and the inflammatory markers interleukin (IL)-6, IL-10, IL-18, IL-1β, IL-33, tumor necrosis factor (TNF)-α, C-reactive protein (CRP), toll-like receptor (TLR) 2, TLR 4, nuclear factor κB, pathogen-associated molecular pattern molecules, lipopolysaccharides, interferon-γ-inducing factor, and JAK STAT.

RESULTS

We identified 755 articles and, after an eligibility analysis, 5 studies were included. The inflammatory markers investigated in the studies were CRP, TNF-α, and IL-33. In patients with CVDs, PhA was negatively associated with CRP and TNF-α in 80% and 100% of the studies, respectively.

CONCLUSIONS

The present results suggested that PhA is inversely associated with inflammatory markers in individuals with CVDs, and its clinical use is encouraged for better therapeutic planning.

Phase angle (PhA) in overweight and obesity: evidence of applicability from diagnosis to weight changes in obesity treatment

Phase angle (PhA) is a recently proposed marker of nutritional status in many clinical conditions. Its use in patients with obesity presents different critical concerns due to the higher variability of the two measured parameters (resistance, R, and reactance, Xc) that contribute to the determination of PhA. Controversial is the relation between PhA and BMI that might vary with graded levels of obesity due to the variation in fat and free fat mass. Obesity is frequently associated with metabolic, hepatic, cardiovascular and kidney diseases that introduce variations in PhA values, in relation to multimorbidity and severity degree of these diseases. It is reported that the improvement of clinical condition is associated with a positive change in PhA. Also, the treatment of obesity with weight loss might confirm this effect, but with different responses in relation to the type and duration of the intervention applied. In fact, the effect appears not only related to the percentage of weight loss but also the possible loss of free fat mass and the nutritional, metabolic and structural modifications that might follow each therapeutic approach to decrease body weight. We can conclude that the PhA could be used as marker of health status in patients with obesity supporting an appropriate weight loss intervention to monitor efficacy and fat free mass preservation.

Decrease phase angle one year after Roux-en-Y bypass and sleeve gastrectomy is related to risks to protein nutritional status

BACKGROUND & AIMS

Phase angle (PhA) has been used as an indicator of nutritional status. However, the significance of PhA reduction after bariatric surgery is less known. This study evaluated PhA and its relation with biochemical parameters and prognostic inflammatory and nutritional indices at a one-year follow-up of patients subjected to Roux-en-Y bypass (RYGB) or sleeve gastrectomy (SG).

METHODS

Our final sample consisted of 25 patients subjected to RYGB and 11 to SG. Body mass index, fat-free mass, fat mass, PhA, serum transthyretin (TTR), albumin, C-reactive protein, alpha-1-acid glycoprotein, and prognostic inflammatory and nutritional indices were evaluated at four time points: before and approximately two, six, and 12 months after RYGB or SG. One-way repeated measures ANOVA or the Friedman test with Tukey's post hoc test was used depending on data distribution. The correlation between PhA and biochemical parameters and indices were evaluated using Spearman's or Pearson's correlation coefficients.

RESULTS

Except for serum albumin, all parameters significantly decreased over time (p < 0.001). Only the RYGB group showed transthyretinTR values below reference ones. Prognostic indices significantly decreased in both groups (p < 0.001). We found a significant positive correlation of PhA with TTR in both RYGB (r = 0.475; p < 0.001) and SG (r = 0.457; p < 0.001).

CONCLUSIONS

Data suggest that at a one-year follow-up after bariatric surgery, lower PhA values might indicate a concomitant loss of visceral protein and a worsening of protein nutritional status.

A Higher Phase Angle Is Associated with Greater Metabolic Equivalents in Women 1 Year After Bariatric Surgery

BACKGROUND

Phase angle (PhA), proposed as an indicator of the number, integrity, and function of cells and evaluated in some clinical situations, decreases after bariatric surgery (BS). In contrast, higher values are found in physically active or exercising individuals. We therefore evaluated the influence of physical activity on PhA after BS.

METHODS

The PhA and body composition (obtained by bioelectrical impedance analysis), physical activity level (obtained by International Physical Activity Questionnaire), and metabolic equivalents (METs) were evaluated in adult women submitted to BS. The PhA and body composition were evaluated at three time points: before and 6 and 12 months after surgery. Physical activity level and METs were measured at the two postoperative time points.

RESULTS

A reduction in PhA was observed 6 (p < 0.01) and 12 months (p < 0.01) after BS, with no significant difference between time points. A moderate or high physical activity level was found in 81% of the volunteers after 6 months and in 65% after 12 months. METs were reduced after 12 months compared to 6 months. A positive correlation (p < 0.05) was observed between PhA and body cell mass after surgery. There was a significant positive correlation (p < 0.01) between PhA and METs after 12 months.

CONCLUSIONS

Physical activity may attenuate the PhA reduction that occurs after BS, with this parameter reflecting the engagement of these patients in this type of activity.

Bioelectrical impedance (BIA)-derived phase angle in adults with obesity: A systematic review

BACKGROUND & AIMS

Bioimpedance analysis-derived phase angle (PhA), as marker of body cell mass and cell integrity, might be altered in obesity, a condition which is characterized by alterations in muscle structure and function. The aim of this systematic review was to evaluate whether and to which extent PhA varies in individuals/patients with excess body weight focusing on: a) changes in PhA due to obesity; b) changes in PhA after bariatric interventions or training programs.

METHODS

According to PRISMA criteria, a systematic literature search until February 2021 using PubMed, Embase, Scopus, and Web of Science was performed. Selection criteria included studies on patients with obesity without comorbidities other than metabolic diseases.

RESULTS

A total of 278 articles were first identified. After removing duplicates and excluding studies that did not fulfil the inclusion criteria, the full text of the remaining 80 potentially relevant studies was examined to finally retrieve 11 cross-sectional and 10 longitudinal studies. Few studies have shown that PhA is lower in individuals/patients with obesity than in controls. The only study on the matter showed a decrease with age after the fourth decade of life. Four out of five studies reported consistently greater mean values in men than in women. In two studies PhA was lower in patients with severe obesity; in addition, Patients with low PhA had higher BMI and PhA was inversely correlated with fat mass. Longitudinal studies showed that PhA markedly decreased after bariatric surgery and slightly increased after training programs.

CONCLUSIONS

Thus, a relatively low number of studies have evaluated PhA in individuals/patients with obesity with sometimes contradictory and preliminary results. PhA might be useful to evaluate muscle quality in individuals/patients with obesity but further studies are needed to more accurately associate this variable with changes in muscle structure and strength, as well as in metabolic functions.

Roux-en-Y Gastric Bypass and Sleeve Gastrectomy Differently Affect Oxidative Damage Markers and their Correlations with Body Parameters

BACKGROUND

Bariatric surgery improves oxidative damage, but little is known about the differences between Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). This study compared changes in lipid and protein oxidative damage markers and their correlations with body parameters of patients before and after RYGB or SG.

METHODS

Body mass index (BMI), bioimpedance parameters, and biochemical parameters including lipid and protein oxidative damage markers were evaluated before and 6 months after surgery. Data were analyzed by t test or Mann-Whitney rank sum test and Spearman's correlation coefficient between oxidative damage and other parameters.

RESULTS

Twenty-five patients were submitted to RYGB and 14 to SG. There was a significant decrease of BMI, fat mass, fat-free mass, phase angle, serum total protein, transthyretin, and C-reactive protein in both groups (p < 0.05). Serum thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), and serum lipids (p < 0.05) were significantly decreased in the RYGB group. TBARS levels were significantly correlated with serum total cholesterol (r = 0.468), LDL (r = 0.439), BMI (r = 0.424), and fat mass (r = 0.40) (p < 0.05). In the SG group, AOPP levels were significantly correlated with serum C-reactive protein (baseline: r = 0.53, 6 months: r = 0.64) (p < 0.05). Alterations in these levels were negatively correlated with changes in BIA parameters [resistance (r = -0.574), reactance (r = -0.736), and phase angle (r = 0.549)] (p < 0.05).

CONCLUSIONS

RYGB seems to be better in attenuating oxidative damage after 6 months. The BMI reduction in the RYGB group suggests a concomitant decrease of lipid oxidative damage. In the SG group, changes in BIA parameters were inversely correlated with protein oxidative damage.

Phase angle and non-alcoholic fatty liver disease before and after bariatric surgery

BACKGROUND

Obesity is a global health problem that is continuing to increase in the young population. In Brazil, the frequency of obesity in 2018 was 19.8%. Several comorbidities are directly associated with obesity, such as non-alcoholic fatty liver disease (NAFLD), which is considered the most common liver disorder in Western countries and affects up to 46% of adults. Bariatric surgery is effective in treating obesity and can improve NAFLD; however, the effect of bariatric surgery on body composition, phase angle (PA), and improving NAFLD needs to be further studied.

AIM

To analyze the PA in the postoperative period of bariatric surgery and to correlate it with changes in body composition and liver disease.

METHODS

This study is a retrospective cohort study of the analysis of the medical records of patients undergoing bariatric surgery in a reference center of a teaching hospital in Porto Alegre over a 2-year period. Patients older than 18 years whose record contained all information relevant to the study were included. The data analyzed were body composition and PA through electrical bioimpedance and NAFLD through liver biopsy in the pre- and postoperative period. The level of significance adopted for the statistical analyses was 5%.

RESULTS

We evaluated 379 patients with preoperative data. Regarding PA, 169 patients were analyzed, and 33 patients had liver biopsy pre- and postoperatively with NAFLD information. In total, 79.4% were female, with a mean age of 39.1 ± 10.6 years. The average body mass index (BMI) was 45.9 ± 7.5 kg/m². The PA showed a mean of 5.8 ± 0.62° in the preoperative period and a significant reduction in the postoperative period. A postoperative reduction in body composition data (skeletal muscle mass, fat percentage, fat mass, body cell mass, BMI and visceral fat area) was shown as well. Regarding liver disease, all patients presented a reduction in the degrees and stages of liver disease in the postoperative period, and some had no degree of liver disease at all.

CONCLUSION

PA decreased after bariatric surgery, with a direct correlation with weight loss and changes in body composition. The decrease in PA was not correlated with the improvement in NAFLD.