M. Cristina Gonzalez

Hand grip strength: Outcome predictor and marker of nutritional status

BACKGROUND & AIMS Among all muscle function tests, measurement of hand grip strength has gained attention as a simple, non-invasive marker of muscle strength of upper extremities, well suitable for clinical use. This review outlines the prognostic relevance of grip strength in various clinical and epidemiologic settings and investigates its suitability as marker of nutritional status in cross-sectional as well as intervention studies. METHODS Studies investigating grip strength as prognostic marker or nutritional parameter in cross-sectional or intervention studies were summarized. RESULTS AND CONCLUSIONS Numerous clinical and epidemiological studies have shown the predictive potential of hand grip strength regarding short and long-term mortality and morbidity. In patients, impaired grip strength is an indicator of increased postoperative complications, increased length of hospitalization, higher rehospitalisation rate and decreased physical status. In elderly in particular, loss of grip strength implies loss of independence. Epidemiological studies have moreover demonstrated that low grip strength in healthy adults predicts increased risk of functional limitations and disability in higher age as well as all-cause mortality. As muscle function reacts early to nutritional deprivation, hand grip strength has also become a popular marker of nutritional status and is increasingly being employed as outcome variable in nutritional intervention studies.

Assessing skeletal muscle mass: historical overview and state of the art

BackgroundEven though skeletal muscle (SM) is the largest body compartment in most adults and a key phenotypic marker of sarcopenia and cachexia, SM mass was until recently difficult and often impractical to quantify in vivo. This review traces the historical development of SM mass measurement methods and their evolution to advances that now promise to provide in-depth noninvasive measures of SM composition.MethodsKey steps in the advancement of SM measurement methods and their application were obtained from historical records and widely cited publications over the past two centuries. Recent advances were established by collecting information on notable studies presented at scientific meetings and their related publications.ResultsThe year 1835 marks the discovery of creatine in meat by Chevreul, a finding that still resonates today in the D3-creatine method of measuring SM mass. Matiegka introduced an anthropometric approach for estimating SM mass in 1921 with the vision of creating a human “capacity” marker. The 1940s saw technological advances eventually leading up to the development of ultrasound and bioimpedance analysis methods of quantifying SM mass in vivo. Continuing to seek an elusive SM mass “reference” method, Burkinshaw and Cohn introduced the whole-body counting-neutron activation analysis method and provided some of the first detailed reports of cancer cachexia in the late 1970s. Three transformative breakthroughs leading to the current SM mass reference methods appeared in the 1970s and early 1980s as follows: the introduction of computed tomography (CT), photon absorptiometry, and magnetic resonance (MR) imaging. Each is advanced as an accurate and/or practical approach to quantifying whole-body and regional SM mass across the lifespan. These advances have led to a new understanding of fundamental body size-SM mass relationships that are now widely applied in the evaluation and monitoring of patients with sarcopenia and cachexia. An intermediate link between SM mass and function is SM composition. Advances in water-fat MR imaging, diffusion tensor imaging, MR elastography, imaging of connective tissue structures by ultra-short echo time MR, and other new MR approaches promise to close the gap that now exists between SM anatomy and function.ConclusionsThe global efforts of scientists over the past two centuries provides us with highly accurate means by which to measure SM mass across the lifespan with new advances promising to extend these efforts to noninvasive methods for quantifying SM composition.

Standardized phase angle from bioelectrical impedance analysis as prognostic factor for survival in patients with cancer

PurposePhase angle (PA), determined by bioelectrical impedance analysis (BIA), has been considered as a prognostic factor in several clinical conditions. The purpose of this study is to investigate PA, after adjusting for sex and age (standardized phase angle; SPA) as a prognostic factor for survival in cancer patients.MethodsA prospective study was conducted in 195 patients before the first chemotherapy course. BIA was performed in all patients and SPA was calculated. The Kaplan-Meier method was used to calculate survival. The Cox regression method was used to evaluate the independent prognostic effect of PA after adjustment for other variables.ResultsPatients with SPA < −1.65 had a smaller survival rate than those with SPA ≥ −1.65 (p < 0.001). Using Cox regression, the mortality rate was higher in patients with SPA < −1.65 (RR 3.12 CI: 2.03–4.79; p < 0.001). After multivariate analysis, patients with PA < −1.65 still presented a higher mortality rate (RR 2.35 CI: 1.41–3.90; p = 0.001).ConclusionsThe present study demonstrates that PA, used as SPA, is an independent prognostic indicator in this group of cancer patients receiving chemotherapy treatment even after adjustment for other prognostic variables.

Adductor pollicis muscle: Reference values of its thickness in a healthy population

BACKGROUND & AIMS Adductor pollicis muscle is the only muscle which could be directly assessed, and its thickness could be useful in muscle mass assessment. Our objective is to determine values of adductor pollicis muscle thickness (APMT) in healthy subjects. METHODS APMT was obtained using a skinfold caliper in 300 healthy subjects, grouped by age and gender, in dominant (DAPMT) and non-dominant (NDAPMT) sides. All patients were assessed by Subjective Global Assessment (SGA). General characteristics of the subjects were obtained by a questionnaire. RESULTS One hundred and fifty men and one hundred and fifty women were evaluated. Their mean age was 44.9+/-18.5 years and they were all well nourished. DAPMT mean values found in men were 26.1+/-4.4mm and in women, 19.8+/-3.3mm, respectively. NDAPMT mean values found in men and women were 25.1+/-4.4mm and 18.7+/-3.1, respectively. Reference values for each gender and age group were created and values below the 5th percentile were considered as limit of normality. CONCLUSIONS This study presents APMT reference values from a healthy population. New studies may demonstrate its role in the evaluation of muscle mass and its association with nutritional status.

New Specific Equation to Estimate Resting Energy Expenditure in Severely Obese Patients

Calculating the estimated resting energy expenditure (REE) in severely obese patients is useful, but there is controversy concerning the effectiveness of available prediction equations (PE) using body weight (BW). We evaluated the efficacy of REE equations against indirect calorimetry (IC) in severely obese subjects and aimed to develop a new equation based on body composition compartments. One hundred and twenty severely obese patients had their REE measured (MREE) by IC and compared to the most commonly used PE (Harris‐Benedict (HB), Ireton‐Jones, Owen, and Mifflin St. Jeor). In a random sample (n = 60), a new REE equation based on fat‐free mass (FFM) was developed and validated. All PE studied failed to estimate REE in severe obesity (low concordance correlation coefficient (CCC) and limits of agreement of nearly 50% of the sample ±10% of MREE). The HB equation using actual BW exhibited good results for all samples when compared to IC (2,117 ± 518 kcal/day by HB vs. 2,139 ± 423 kcal/day by MREE, P > 0.01); these results were blunted when patients were separated by gender (2,771 vs. 2,586 kcal/day, P < 0.001 in males and 1,825 vs. 1,939 kcal/day, P < 0.001 in females). A new resting energy expenditure equation prediction was developed using FFM, Horie‐Waitzberg, & Gonzalez, expressed as 560.43 + (5.39 × BW) + (14.14 × FFM). The new resting energy expenditure equation prediction, which uses FFM and BW, demonstrates higher accuracy, precision, CCC, and limits of agreement than the standard PE in patients when compared to MREE (2,129 ± 45 kcal/day vs. 2,139 ± 423 kcal/day, respectively, P = 0.1).The new equation developed to estimate REE, which takes into account both FFM and BW, provides better results than currently available equations.

Time to Correctly Predict the Amount of Weight Loss with Dieting

After a thoughtfulanalysis of the existing literature, Wishnofskyconcluded that “the caloric equivalent of one pound of bodyweight lost” or “gained will be 3,500.” Fifty years later andwith thousands of citations in the scientific literature andthe lay press, Hill and his colleagues repeated the often-used statement“an energy deficit of approximately 3,500kcal is needed to lose 1 lb of body weight” in the authorita-tive textbook, ModernNutritioninHealthandDisease.

Phase Angle and Impedance Ratio: Reference Cut-Points From the United States National Health and Nutrition Examination Survey 1999-2004 From Bioimpedance Spectroscopy Data.

Background: Raw bioimpedance parameters (eg, 50-kHz phase angle [PA] and 200-kHz/5-kHz impedance ratio [IR]) have been investigated as predictors of nutrition status and/or clinical outcomes. However, their validity as prognostic measures depends on the availability of appropriate reference data. Using a large and ethnically diverse data set, we aimed to determine if ethnicity influences these measures and provide expanded bioimpedance reference data for the U.S. population. Methods: The National Health and Nutrition Examination Survey (NHANES) is an ongoing compilation of studies conducted by the U.S. Centers for Disease Control and Prevention designed to monitor nutrition status of the U.S. population. The NHANES data sets analyzed were from the years 1999–2000, 2001–2002, and 2003–2004. Results: Multivariate analysis showed that PA and IR differed by body mass index (BMI), age, sex, and ethnicity (n = 6237; R2 = 41.2%, P < .0001). Suggested reference cut-points for PA stratified by age decade, ethnicity, and sex are provided. Conclusion: Ethnicity is an important variable that should be accounted for when determining population reference values for PA and IR. We have provided sex-, ethnicity-, and age decade–specific reference values from PA for use by future studies in U.S. populations. Interdevice differences are likely to be important contributors to variability across published population-specific reference data and, where possible, should be evaluated in future research. Ultimately, further validation with physiologically relevant reference measures (eg, dual-energy x-ray absorptiometry) is necessary to determine if PA/IR are appropriate bedside tools for the assessment of nutrition status in a clinical population.

Introduction of an Omega-3 Enriched Oral Supplementation for Cancer Patients Close to the First Chemotherapy: May It Be a Factor for Poor Compliance?

The present study aims to evaluate compliance of cancer patients to EPA-enriched supplementation at the beginning of chemotherapy, and its effects on inflammation. Gastrointestinal and lung cancer patients were randomly assigned to receive nutritional supplement enriched with 2.2 g EPA or standard isocaloric one. Supplements were introduced 72 h before the first chemotherapy and continued for 4 wk. Serum C-reactive protein was measured and its variation was analyzed according to tumor location and treatment group. Compliance was assessed by phone contact and counting of supplement bottles returned after treatment. Sixty-nine patients were assessed, mean aged 65.5 yr old, most of them (59%) men. Gastrointestinal cancer was more prevalent and lung cancer had the highest C-reactive protein values (P = 0.009). Twenty-four patients interrupted treatment (trend for more interruption in EPA group), mainly because of gastrointestinal intolerance. No difference was found in C-reactive protein variation between EPA and control groups after treatment. Lung tumors showed higher inflammation than gastrointestinal ones. A short intervention with EPA was insufficient to reduce inflammation, which may be caused by the frequent abandoning of treatment. The beginning of chemotherapy may not be the optimal time point to initiate EPA supplementation because uncomfortable effects of both treatments may lead to poor adherence.