Evaluation of bone density and skeletal muscle mass after sleeve gastrectomy using computed tomography method

Introduction

Sleeve gastrectomy is the most common surgical procedure to reduce weight and treat metabolic complications in patients with moderate-to-severe obesity; however, it affects the musculoskeletal system. Dual-energy X-ray absorptiometry (DXA), which is commonly used to measure bone mineral density (BMD), may be affected by excess fat tissue around the bones, interrupting BMD measurement. Due to the strong correlation between DXA and the Hounsfield units (HU) obtained from computed tomography (CT) scans, BMD assessment using clinical abdominal CT scans has been useful. To date, there has been no report of detailed CT evaluation in patients with severe obesity after sleeve gastrectomy.

Objective

This study investigated the effect of sleeve gastrectomy in severely obese patients on bone and psoas muscle density, and cross-sectional area using retrospective clinical CT scans.

Methods

This was a retrospective observational study that included 86 patients (35 males and 51 females) who underwent sleeve gastrectomy between March 2012 and May 2019. Patients' clinical data (age at the time of surgery, sex, body weight, body mass index (BMI), comorbidities, and preoperative and postoperative blood test results, HU of the lumbar spine and psoas muscle and psoas muscle mass index (PMI)) were evaluated.

Results

The mean age at the time of surgery was 43 years, and the body weight and BMI significantly reduced (p < 0.01) after surgery. The mean hemoglobin A1c level showed significant improvement in males and females. Serum calcium and phosphorus levels remained unchanged before and after surgery. In CT analysis, HU of the lumbar spine and psoas muscle showed no significant decrease, but PMI showed a significant decrease (p < 0.01).

Conclusions

Sleeve gastrectomy could dramatically improve anthropometric measures without causing changes in serum calcium and phosphorus levels. Preoperative and postoperative abdominal CT revealed no significant difference in the bone and psoas muscle density, and the psoas muscle mass was significantly decreased after sleeve gastrectomy.

Impact of hematopoietic stem cell transplantation in glycogen storage disease type Ib: A single-subject research design using 13C-glucose breath test

Background

Glycogen storage disease type Ib (GSD Ib) is an autosomal recessively inherited deficiency of the glucose-6-phosphate translocase (G6PT). Clinical features include a combination of a metabolic phenotype (fasting hypoglycemia, lactic acidosis, hepatomegaly) and a hematologic phenotype with neutropenia and neutrophil dysfunction. Dietary treatment involves provision of starches such as uncooked cornstarch (UCCS) and Glycosade® to provide prolonged enteral supply of glucose. Granulocyte colony-stimulating factor (G-CSF) is the treatment of choice for neutropenia. Because long-term stimulation of hematopoiesis with G-CSF causes serious complications such as splenomegaly, hypersplenism, and osteopenia; hematopoietic stem cell transplantation (HSCT) has been considered in some patients with GSD Ib to correct neutropenia and avoid G-CSF related adverse effects. Whether HSCT also has an effect on the metabolic phenotype and utilization of carbohydrate sources has not been determined.

Objective

Our objective was to measure the utilization of starch in a patient with GSD Ib before and after HSCT using the minimally invasive ¹³C-glucose breath test (¹³C-GBT).

Design

A case of GSD Ib (18y; female) underwent ¹³C-GBT four times: UCCS (pre-HSCT), UCCS (3, 5 months post-HSCT) and Glycosade® (6 months post-HSCT) with a dose of 80 g administered via nasogastric tube after a 4 h fast according to our patient's fasting tolerance. Breath samples were collected at baseline and every 30 min for 240 min. Rate of CO₂ production was measured at 120 min using indirect calorimetry. Finger-prick blood glucose was measured using a glucometer hourly to test hypoglycemia (glucose <4 mmol/L). Biochemical and clinical data were obtained from the medical records as a post-hoc chart review.

Results

UCCS utilization was significantly higher in GSD Ib pre-HSCT, which reduced and stabilized 5 months post-HSCT. UCCS and Glycosade® utilizations were low and not different at 5 and 6 months post-HSCT. Blood glucose concentrations were not significantly different at any time point.

Conclusions

Findings show that HSCT stabilized UCCS utilization, as reflected by lower and stable glucose oxidation. The results also illustrate the application of ¹³C-GBT to examine glucose metabolism in response to various carbohydrate sources after other treatment modalities like HSCT in GSD Ib.

Sarcopenia in the Cirrhotic Patient: Current Knowledge and Future Directions

Cirrhosis predisposes to abnormalities in energy, hormonal, and immunological homeostasis. Disturbances in these metabolic processes create susceptibility to sarcopenia or pathological muscle wasting. Sarcopenia is prevalent in cirrhosis and its presence portends significant adverse outcomes including the length of hospital stay, infectious complications, and mortality. This highlights the importance of identification of at-risk individuals with early nutritional, therapeutic and physical therapy intervention. This manuscript summarizes literature relevant to sarcopenia in cirrhosis, describes current knowledge, and elucidates possible future directions.

Impact of simple equation for estimating appendicular skeletal muscle mass in patients with stable coronary artery disease undergoing percutaneous coronary intervention

Background

Sarcopenia, which is evaluated based on appendicular skeletal muscle mass (ASM) using dual-energy X-ray absorptiometry and bioelectrical impedance analysis, is a prognostic predictor for adverse outcomes in patients with coronary artery disease (CAD). However, a simple equation for estimating ASM is yet to be validated in clinical practice.

Methods

We enrolled 2211 patients with CAD who underwent percutaneous coronary intervention at our hospital between 2010 and 2017. The mean age was 68 years and 81.5 % were men. Patients were divided into 2 groups based on each ASM index (ASMI): low; male < 7.3 and female < 5.0 and high; male ≥ 7.3 and female ≥ 5.0. ASM was calculated using the following equation: 0.193 × bodyweight + 0.107 × height - 4.157 × gender - 0.037 × age - 2.631. Primary endpoints were major adverse cardiac events (MACE, which includes cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization for heart failure), and all-cause mortality.

Results

During the median follow-up period of 4.8 years, cumulative incidence of events were significantly higher in the low ASMI group. Cox proportional hazards model revealed that the low ASMI group had a significantly higher risk of primary endpoints than the high ASMI group (all-cause mortality; hazard ratio (HR): 2.13, 95 % confidence interval [CI]: 1.40-3.22, p < 0.001 and 4-point MACE; HR: 1.72, 95 % CI: 1.12-2.62, p = 0.01). Similar trends were observed after stratification by age of 65 years.

Conclusion

Low ASMI, evaluated using the aforementioned equation, is an independent predictor of MACE and all-cause mortality in patients with CAD.

Comparison of Anthropometry, Bioelectrical Impedance, and Dual-energy X-ray Absorptiometry for Body Composition in Cirrhosis

Background & aims

This study was planned to evaluate triceps skinfold thickness (TSFT), mid-arm muscle circumference (MAMC) and bioelectrical impedance analysis (BIA) for assessing body composition using dual-energy X-ray absorptiometry (DEXA) (reference) and to predict fat mass (FM) and fat-free mass (FFM) in patients with cirrhosis.

Methods

FM and FFM were assessed by using DEXA and BIA. Skin-fold calliper was used for measuring TSFT, and MAMC was calculated. Bland-Altman plot was used to determine agreement and linear regression analysis for obtaining equations to predict FM and FFM.

Results

Patients with cirrhosis (n = 302, 241 male, age 43.7 ± 12.0 years) were included. Bland-Altman plot showed very good agreement between BIA and DEXA for the estimation of FM and FFM. Majority of patients were within the limit of agreement: FM (98%) and FFM (96.4%). BIA shows a positive correlation with DEXA:FM (r = 0.73, P ≤ 0.001) and FFM (r = 0.86, P ≤ 0.001). DEXA (FM and FFM) shows a positive correlation with TSFT (r = 0.69, P ≤ 0.01) and MAMC (r = 0.61, P ≤ 0.01). The mean difference between the observed and predicted value of FM and FFM by BIA in the developmental set was 0.01 and 0.05, respectively; whereas in the validation set, it was -0.13 and 0.86, respectively. The mean difference between the observed and predicted value of TSFT and MAMC in the developmental set was 0.43 and 0.07; whereas, in the validation set, it was 0.16 and 0.48, respectively.

Conclusion

Anthropometry (TSFT and MAMC) and BIA are simple and easy to use and can be a substitute of DEXA for FM and FFM assessment in routine clinical settings in patients with cirrhosis.

Effects of testosterone undecanoate on performance during multi-stressor military operations: A trial protocol for the Optimizing Performance for Soldiers II study

Background

Previously, young males administered 200 mg/week of testosterone enanthate during 28 days of energy deficit (EDef) gained lean mass and lost less total mass than controls (Optimizing Performance for Soldiers I study, OPS I). Despite that benefit, physical performance deteriorated similarly in both groups. However, some experimental limitations may have precluded detection of performance benefits, as performance measures employed lacked military relevance, and the EDef employed did not elicit the magnitude of stress typically experienced by Soldiers conducting operations. Additionally, the testosterone administered required weekly injections, elicited supra-physiological concentrations, and marked suppression of endogenous testosterone upon cessation. Therefore, this follow-on study will address those limitations and examine testosterone's efficacy for preserving Solder performance during strenuous operations.

Methods

In OPS II, 32 males will participate in a randomized, placebo-controlled, double-blind trial. After baseline testing, participants will be administered either testosterone undecanoate (750 mg) or placebo before completing four consecutive, 5-day cycles simulating a multi-stressor, sustained military operation (SUSOPS). SUSOPS will consist of two low-stress days (1000 kcal/day exercise-induced EDef; 8 h/night sleep), followed by three high-stress days (3000 kcal/day and 4 h/night). A 23-day recovery period will follow SUSOPS. Military relevant physical performance is the primary outcome. Secondary outcomes include 4-comparment body composition, muscle and whole-body protein turnover, intramuscular mechanisms, biochemistries, and cognitive function/mood.

Conclusions

OPS II will determine if testosterone undecanoate safely enhances performance, while attenuating muscle and total mass loss, without impairing cognitive function, during and in recovery from SUSOPS.

Trial Registration

ClinicalTrials.gov Identifier: NCT04120363.

A dynamic association between myosteatosis and liver stiffness: Results from a prospective interventional study in obese patients

Background & Aims

Retrospective cross-sectional studies linked sarcopenia and myosteatosis with metabolic dysfunction-associated fatty liver disease (MAFLD). Here, we wanted to clarify the dynamic relationship between sarcopenia, myosteatosis, and MAFLD.

Methods

A cohort of 48 obese patients was randomised for a dietary intervention consisting of 16 g/day of inulin (prebiotic) or maltodextrin (placebo) supplementation. Before and after the intervention, we evaluated liver steatosis and stiffness with transient elastography (TE); we assessed skeletal muscle index (SMI) and skeletal muscle fat index (SMFI) (a surrogate for absolute fat content in muscle) using computed tomography (CT) and bioelectrical impedance analysis (BIA).

Results

At baseline, sarcopenia was uncommon in patients with MAFLD (4/48, 8.3%). SMFI was higher in patients with high liver stiffness than in those with low liver stiffness (640.6 ± 114.3 cm²/ Hounsfield unit [HU] vs. 507.9 ± 103.0 cm²/HU, p = 0.001). In multivariate analysis, SMFI was robustly associated with liver stiffness even when adjusted for multiple confounders (binary logistic regression, p <0.05). After intervention, patients with inulin supplementation lost weight, but this was not associated with a decrease in liver stiffness. Remarkably, upon intervention (being inulin or maltodextrin), patients who lowered their SMFI, but not those who increased SMI, had a 12.7% decrease in liver stiffness (before = 6.36 ± 2.15 vs. after = 5.55 ± 1.97 kPa, p = 0.04).

Conclusions

Myosteatosis, but not sarcopenia, is strongly and independently associated with liver stiffness in obese patients with MAFLD. After intervention, patients in which the degree of myosteatosis decreased reduced their liver stiffness, irrespective of body weight loss or prebiotic treatment. The potential contribution of myosteatosis to liver disease progression should be investigated.

Clinical Trials registration number

NCT03852069.

Lay summary

The fat content in skeletal muscles (or myosteatosis) is strongly associated with liver stiffness in obese patients with MAFLD. After a dietary intervention, patients in which the degree of myosteatosis decreased also reduced their liver stiffness. The potential contribution of myosteatosis to liver disease progression should be investigated.

•

Low-radiation CT scan enables muscle evaluation (quantity and composition).

•

Muscle mass is not low in patients with MAFLD and high liver stiffness.

•

In contrast, myosteatosis is strongly associated with liver stiffness.

•

Lower myosteatosis after dietary intervention is associated with improved MAFLD.

Improving Physical Activity and Body Composition in a Medical Workplace Using Brief Goal Setting

Objective

To evaluate the use of a wearable activity tracker and brief feedback in the workplace to motivate employees to improve activity.

Patients and Methods

A total of 135 adult participants were randomized to 1 of 3 groups: control group (blinded to their step activity), intervention group (received counseling based on their step count), or no step-tracking device group. Participants were recruited from June 27, 2016, through February 21, 2018.

Results

Most of the 135 participants were women (84%), with a mean ± SD age of 42.6±10.1 years. Most participants (96%) completed 11 of the 12 weeks of step counts. Comparing treatment groups at week 12 (end of treatment), the intervention group (vs the control group) had significantly more steps (644.8; P<.01), had an 11.1% increase in step count from baseline (P<.01), was more likely to achieve goal (odds ratio=1.73; P=.02), increased distance traveled per week (0.46 miles; P<.01) and calories burned (90.6; P<.01), and had a decrease in some bioelectrical impedance measurements over time, including a greater loss in body fat mass (–0.90 kg; P=.01), percentage fat (–0.96; P<.01), and visceral fat level (–0.60; P<.01). Finally, the intervention group indicated significantly greater satisfaction with their assigned randomization (89% vs 77%; P=.01) and greater confidence in the effectiveness of their activity tracker (P<.01).

Conclusion

Brief counseling accompanied by use of a step-counting device can improve workplace activity, which, in turn, can increase steps and decrease body fat, including visceral fat.

Trial Registration

clinicaltrials.gov Identifier: NCT02794727

Effects on body composition and handgrip strength of a nutritional intervention for malnourished HIV-infected adults referred for antiretroviral therapy: a randomised controlled trial

Lipid-based nutrient supplements (LNS) may be beneficial for malnourished HIV-infected patients starting antiretroviral therapy (ART). We assessed the effect of adding vitamins and minerals to LNS on body composition and handgrip strength during ART initiation. ART-eligible HIV-infected patients with BMI <18·5 kg/m² were randomised to LNS or LNS with added high-dose vitamins and minerals (LNS-VM) from referral for ART to 6 weeks post-ART and followed up until 12 weeks. Body composition by bioelectrical impedance analysis (BIA), deuterium (²H) diluted water (D₂O) and air displacement plethysmography (ADP), and handgrip strength were determined at baseline and at 6 and 12 weeks post-ART, and effects of LNS-VM v. LNS at 6 and 12 weeks investigated. BIA data were available for 1461, D₂O data for 479, ADP data for 498 and handgrip strength data for 1752 patients. Fat mass tended to be lower, and fat-free mass correspondingly higher, by BIA than by ADP or D₂O. At 6 weeks post-ART, LNS-VM led to a higher regain of BIA-assessed fat mass (0·4 (95 % CI 0·05, 0·8) kg), but not fat-free mass, and a borderline significant increase in handgrip strength (0·72 (95 % CI −0·03, 1·5) kg). These effects were not sustained at 12 weeks. Similar effects as for BIA were seen using ADP or D₂O but no differences reached statistical significance. In conclusion, LNS-VM led to a higher regain of fat mass at 6 weeks and to a borderline significant beneficial effect on handgrip strength. Further research is needed to determine appropriate timing and supplement composition to optimise nutritional interventions in malnourished HIV patients.

A cross-sectional analysis of dietary protein intake and body composition among Chinese Americans

Favourable body composition has been associated with higher dietary protein intake. However, little is known regarding this relationship in a population of Chinese Americans (CHA), who have lower BMI compared with other populations. The aim of the present study was to assess the relationship between dietary protein intake, fat mass (FM) and fat-free mass (FFM) in CHA. Data were from the Chinese American Cardiovascular Health Assessment (CHA CHA) 2010-2011 (n 1707); dietary intake was assessed using an adapted and validated FFQ. Body composition was assessed using bioelectrical impedance analysis. The associations between protein intake (% energy intake) and BMI, percentage FM (FM%), percentage FFM (FFM%), FM index (FMI) and FFM index (FFMI) were examined using multiple linear regression adjusted for age, sex, physical activity, acculturation, total energy intake, sedentary time, smoking status, education, employment and income. There was a significant positive association between dietary protein and BMI (B = 0·056, 95 % CI 0·017, 0·104; P = 0·005), FM (B = 0·106, 95 % CI 0·029, 0·184; P = 0·007), FM% (B = 0·112, 95 % CI 0·031, 0·194; P = 0·007) and FMI (B = 0·045, 95 % CI 0·016, 0·073; P = 0·002). There was a significant negative association between dietary protein and FFM% (B = -0·116, 95 % CI -0·196, -0·036; P = 0·004). In conclusion, higher dietary protein intake was associated with higher adiposity; however, absolute FFM and FFMI were not associated with dietary protein intake. Future work examining the relationship between protein source (i.e. animal) and body composition is warranted in this population of CHA.

Validation of bioelectrical impedance analysis in Ethiopian adults with HIV

Bioelectrical impedance analysis (BIA) is an inexpensive, quick and non-invasive method to determine body composition. Equations used in BIA are typically derived in healthy individuals of European descent. BIA is specific to health status and ethnicity and may therefore provide inaccurate results in populations of different ethnic origin and health status. The aim of the present study was to test the validity of BIA in Ethiopian antiretroviral-naive HIV patients. BIA was validated against the 2H dilution technique by comparing fat-free mass (FFM) measured by the two methods using paired t tests and Bland-Altman plots. BIA was based on single frequency (50 kHz) whole-body measurements. Data were obtained at three health facilities in Jimma Zone, Oromia Region, South-West Ethiopia. Data from 281 HIV-infected participants were available. Two-thirds were female and the mean age was 32·7 (sd 8·6) years. Also, 46 % were underweight with a BMI below 18·5 kg/m2. There were no differences in FFM between the methods. Overall, BIA slightly underestimated FFM by 0·1 kg (-0·1, 95 % CI -0·3, 0·2 kg). The Bland-Altman plot indicated acceptable agreement with an upper limit of agreement of 4·5 kg and a lower limit of agreement of -4·6 kg, but with a small correlation between the mean difference and the average FFM. BIA slightly overestimated FFM at low values compared with the 2H dilution technique, while it slightly underestimated FFM at high values. In conclusion, BIA proved to be valid in this population and may therefore be useful for measuring body composition in routine practice in HIV-infected African individuals.

The Phase Angle of the Bioelectrical Impedance Analysis as Predictor of Post-Bariatric Weight Loss Outcome. Obes Surg. 2017;27:665-669. [PMID: 27465938 DOI: 10.1007/s11695-016-2315-9]

BACKGROUND

Bariatric surgery is proven to be the most effective therapy for obesity. However, the targeted weight reduction is not always achieved. Reliable predictors for postoperative success are rare. Also, most available predictors, such as gender and socioeconomic status, cannot be influenced. The aim of the study was to assess the reliability of the phase angle (PhA) as a predictor of weight reduction and body composition after bariatric surgery.

METHODS

One hundred seventy-three patients (127 with Roux-en-Y gastric bypass and 46 with sleeve gastrectomy), treated between January 2004 and December 2012, were included into this prospective trial. Bioelectrical impedance analysis (BIA) was performed before and five times within the first year after the operation. Correlation between excess weight loss (EWL) was calculated using Pearson's correlation coefficient and a receiver operating characteristic (ROC) curve.

RESULTS

The average weight loss was significant with a total weight loss of 30.1 %, while the PhA did not show any significant decrease during the first 12 months after surgery. The correlation between the preoperative PhA and the postoperative EWL was significant after 6 weeks and after 6, 9, and 12 months. The ROC curve has an area of 0.7. The best point of the curve is a PhA of 3.9° with a sensitivity of 81 % and a specificity of 54 %.

CONCLUSIONS

PhA may be a useful predictor of EWL after bariatric surgery, and a PhA of 3.9° was calculated as the most suitable cut-off for a successful operation.

Excessive adiposity at low BMI levels among women in rural Bangladesh

Asian populations have a higher percentage body fat (%BF) and are at higher risk for CVD and related complications at a given BMI compared with those of European descent. We explored whether %BF was disproportionately elevated in rural Bangladeshi women with low BMI. Height, weight, mid-upper arm circumference, triceps and subscapular skinfolds and bioelectrical impedance analysis (BIA) were measured in 1555 women at 3 months postpartum. %BF was assessed by skinfolds and by BIA. BMI was calculated in adults and BMI Z-scores were calculated for females <20 years old. Receiver operating characteristic (ROC) curves found the BMI and BMI Z-score cut-offs that optimally classified women as having moderately excessive adipose tissue (defined as >30 % body fat). Linear regressions estimated the association between BMI and BMI Z-score (among adolescents) and %BF. Mean BMI was 19·2 (sd 2·2) kg/m², and mean %BF was calculated as 23·7 (sd 4·8) % by skinfolds and 23·3 (sd 4·9) % by BIA. ROC analyses indicated that a BMI value of approximately 21 kg/m² optimised sensitivity (83·6 %) and specificity (84·2 %) for classifying subjects with >30 % body fat according to BIA among adults. This BMI level is substantially lower than the WHO recommended standard cut-off point of BMI ≥ 25 kg/m². The equivalent cut-off among adolescents was a BMI Z-score of –0·36, with a sensitivity of 81·3 % and specificity of 80·9 %. These findings suggest that Bangladeshi women exhibit excess adipose tissue at substantially lower BMI compared with non-South Asian populations. This is important for the identification and prevention of obesity-related metabolic diseases.