Total body protein in chronic diseases and in aging

Associations between a patient-reported outcome (PRO) measure of sarcopenia and falls, functional status, and physical performance in older patients with cancer

OBJECTIVE

In older patients with cancer, we aimed to investigate associations between a patient-reported outcome measure for sarcopenia (SarcoPRO) and the Short Physical Performance Battery (SPPB), self-reported falls, and limitations in instrumental activities of daily living (IADLs).

MATERIALS AND METHODS

Assessments were conducted as part of the initial evaluation of older, often frail, patients with cancer seen in the Specialized Oncology Care and Research in the Elderly (SOCARE) clinic. Univariate associations were evaluated using Spearman's correlation and Wilcoxon sign ranked tests. Logistic regressions were used to identify associations of clinical factors and SarcoPRO scores or SPPB scores with falls and IADL limitations.

RESULTS

In total, 174 older patients with cancer were evaluated. A moderate correlation was found between the SarcoPRO and the SPPB (ρ=0.62). After adjusting for multiple clinical factors, neither the SarcoPRO nor the SPPB were associated with falls. In contrast, both higher SarcoPRO (i.e., worse) and lower SPPB (i.e., worse) scores were associated with limitations in IADLs (odds ratio for one unit change in predictor: SarcoPRO: 1.06, p<0.0001; SPPB: 0.71, p=0.003, respectively). Models using the SarcoPRO and SPPB explained similar amounts of variability in association with IADL limitations (AUC: 0.88 vs. 0.87, respectively).

CONCLUSIONS

The SarcoPRO was moderately associated with the SPPB, an objective measure of physical performance, and was associated with limitations in IADLs. Thus, older patients with cancer who present with IADL limitations should be screened for sarcopenia. The SarcoPRO shows promise as a measure for screening as well as outcome assessment for research on sarcopenia.

Long-term changes in body composition after pancreaticoduodenectomy

BACKGROUND

The Whipple's procedure (WP) is a major operation that adds a further demand on the body's nutritional reserves and therefore body composition after the effect of pancreatic cancer. The aim was to document changes in body composition changes that occur during the first six months after a WP for a pancreatic cancer malignancy.

METHODS

Twenty-seven (14 males, 13 females) consecutive WP patients had body composition measured at baseline and then at 2, 5, 14 and 26 weeks after surgery. These included; anthropometric measure (weight, skin folds and arm muscle area (AMA)), total body measures of protein (TBP), potassium (TBK), water (TBW) and fat mass (FM). Changes were compared using repeated measures analysis of variance.

RESULTS

Hospital nutritional care maintained TBP and TBK but at 2 weeks there was a loss of FM (P= 0.037). The nadir of weight loss (P < 0.001) occurred at 5 weeks because of losses of protein (P= 0.007), fat (P < 0.001) and potassium (P= 0.045) but not water. Although weight and FM were still significantly less than baseline measures at 26 weeks weight, TBP, TBK and AMA were not significantly different to preoperative values.

CONCLUSIONS

Although at 6 months, important measures of the metabolically functioning tissue, TBP and TBK, have returned to preoperative values significant losses occurred during the first 3 weeks after discharge from hospital and FM did not return to preoperative values. These results suggest the need to improve post-discharge nutritional care.

Evidence for a novel serum factor distinct from zinc alpha-2 glycoprotein that promotes body fat loss early in the development of cachexia

We provide evidence that a factor other than the previously identified lipid mobilizing factor, zinc alpha-2 glycoprotein, promotes lipolysis in the MCA-induced sarcoma-bearing cachexia model. Cachexia is characterized by progressive loss of adipose tissue and skeletal muscle without a concurrent increase in food intake to restore lost tissue stores. We compared tumor-bearing ad lib fed (TB) animals to nontumor bearing ad lib fed (NTB) animals or nontumor-bearing pair-fed (PF) animals at various time points throughout development of tumor derived cachexia. Prior to cachexia, the TB animals lost more than 10 +/- 0.7% of their body fat before losing protein mass and decreasing their food intake. Fat loss occurred because adipocyte size, not number, was reduced. Increased turnover of palmitate and significantly higher serum triglyceride levels prior to cachexia were further indicators of an early loss of lipid from the adipocytes. Yet, circulating levels of norepinephrine, epinephrine, TNF-alpha, and zinc alpha-2 glycoprotein were not increased prior to the loss of fat mass. We provide evidence for a serum factor(s), other than zinc alpha-2 glycoprotein, that stimulates release of glycerol from 3T3-L1 adipocytes and promotes the loss of stored adipose lipid prior to the loss of lean body mass in this model.

The skeletal muscle transcript profile reflects accommodative responses to inadequate protein intake in younger and older males

Inadequate protein intake initiates adverse changes in skeletal muscle function and structure (i.e., an accommodative response). mRNA level changes due to short-term inadequate dietary protein might be an early indication of subsequent accommodation. The aims of this study were to assess the effects of dietary protein and the diet-by-age interaction on the skeletal muscle transcriptome. Twelve younger (21-43 y) and 10 older (63-79 y) men completed three controlled feeding trials with protein intakes of 0.50 (LPro: lower protein), 0.75 (MPro: medium protein) and 1.00 g protein·kg body weight⁻¹·day⁻¹ (HPro: higher protein). A fasting state biopsy was taken on Day 12 of each trial. Global changes in transcript levels were assessed with Affymetrix genechips and expression patterns determined using self-organizing maps. Nine hundred fifty-eight transcripts were differentially expressed (P<.05) by diet and 853 had a diet-by-age interaction (P<.05). The results for diet alone revealed that LPro was associated with up-regulation of transcripts related to ubiquitin-dependent protein catabolism and muscle contraction and LPro and MPro resulted in up-regulation of transcripts related to apoptosis and down-regulation of transcripts related to cell differentiation, muscle and organ development, extracellular space and responses to stimuli and stress. The diet-by-age effect on protein modification transcripts was consistent with the older males being less responsive to anabolic stimuli (lower protein synthesis at HPro) and more responsive to a catabolic state (protein breakdown at LPro). Changes in skeletal muscle mRNA levels in younger and older males to protein intake near or below the recommended dietary allowance are indicative of an early accommodative response.

The importance of dietary protein in human health: combating protein deficiency in sub-Saharan Africa through transgenic biofortified sorghum

Child malnutrition is increasing in Africa. Protein deficiency is an important cause since protein is essential for both growth and maintenance of muscle mass. Sorghum is a major staple food in Africa on account of its hardiness as a crop. However, sorghum protein is very deficient in the indispensable amino acid lysine and on cooking has poor protein digestibility. This results in sorghum having a very low Protein Digestibility Corrected Amino Acid Score (PDCAAS). The Africa Biofortified Sorghum project, a Grand Challenges in Global Heath project, is undertaking research to biofortify sorghum in terms of protein and micronutrient quality using genetic engineering. Lysine and protein digestibility have been improved by suppression of synthesis of the kafirin storage proteins. Transgenic biofortified sorghum has double the PDCAAS of conventional sorghum. This improvement should enable a young child to meet most of its protein and energy requirements from biofortified sorghum porridge. This together with the improvement in micronutrients could provide the basis of a sustainable and broadly comprehensive solution to child malnutrition in many African countries.

Body composition of children with chronic and end-stage renal failure

AIM

Protein energy malnutrition is common in children with chronic renal failure (CRF) and may negatively impact on clinical outcome. Although the aetiology of malnutrition is multifactorial, descriptive information on body composition may guide nutritional interventions aimed at optimising nutritional status.

METHODS

This prospective cohort study in children with CRF was conducted from April 1999 to November 2000. Patients were categorised according to their glomerular filtration rate (GFR) into CRF and end-stage renal failure (ESRF). Body composition was assessed based on anthropometry, total body potassium (TBK), total body protein (TBP) and dual X-ray absorptiometry (DEXA).

RESULTS

Fifteen patients (10 male, 5 female; mean age: 13.4 +/- 4.3 years) were studied, including eight patients with CRF (mean GFR: 17.0 +/- 7.2 mL/min/1.73 m(2)) and seven patients with ESRF (mean GFR: 6.4 +/- 1.7 mL/min/1.73 m(2)). Patients in both groups (n = 15) had deficits in height and TBP (mean z-score height-for-age: -1.19 +/- 1.05, P < 0.01; mean z-score TBP: -0.71 +/- 0.71, P < 0.05). There were no significant differences in weight, height, fat-free mass, TBK and TBP between patients with CRF and ESRF.

CONCLUSIONS

Linear growth impairment and decreased TBP are common in children with chronic and ESRF. TBK and DEXA may underestimate the degree of malnutrition in these patients.

Dietary treatment of rheumatoid cachexia with β-hydroxy-β-methylbutyrate, glutamine and arginine: A randomised controlled trial

BACKGROUND & AIMS

Rheumatoid arthritis (RA) is complicated by cytokine-driven alterations in protein and energy metabolism and consequent muscle wasting (cachexia). The aim of this randomised controlled trial was to investigate the efficacy of a mixture of beta-hydroxy-beta-methylbutyrate, glutamine and arginine (HMB/GLN/ARG) as nutritional treatment for rheumatoid cachexia.

METHODS

Forty RA patients supplemented their diet with either HMB/GLN/ARG or a nitrogen (7.19 g/day) and calorie (180 kcal/day) balanced mixture of alanine, glutamic acid, glycine, and serine (placebo) for 12 weeks. Body composition and other outcomes were assessed at baseline and follow-up, and analysed by mixed ANOVA.

RESULTS

Dietary supplementation with HMB/GLN/ARG was not superior to placebo in the treatment of rheumatoid cachexia (groupxtime interactions P>0.05 for all outcomes). Both amino acid mixtures significantly increased (main effect of time) fat-free mass (727+/-1186 g, P<0.01), total body protein (719+/-1703 g, P=0.02), arms (112+/-183 g, P<0.01) and legs (283+/-534 g, P<0.01) lean mass, and some measures of physical function. No significant adverse event occurred during the study, but patients in the HMB/GLN/ARG group reported fewer gastrointestinal complaints compared to placebo.

CONCLUSIONS

Dietary supplementation with HMB/GLN/ARG is better tolerated but not more effective in reversing cachexia in RA patients compared to the mixture of other non-essential amino acids used as placebo. Further controlled studies are necessary to confirm the beneficial anabolic and functional effects of increased nitrogen intake in this population.

Body composition and time course changes in regional distribution of fat and lean tissue in unselected cancer patients on palliative care—Correlations with food intake, metabolism, exercise capacity, and hormones

BACKGROUND

Several investigations that yielded different results in terms of net changes in body composition of weight-losing cancer patients have been reported that employed a variety of methods based on fundamentally different technology. Most of those reports were cross-sectional, whereas to the authors' knowledge there is sparse information available on longitudinal follow-up measurements in relation to other independent methods for the assessment of metabolism and performance.

METHODS

For the current report, the authors evaluated time course changes in body composition (dual-energy X-ray absorptiometry) with measurements of whole body and regional distribution of fat and lean tissue in relation to food and dietary intake, host metabolism (indirect calorimetry), maximum exercise capacity (walking test), and circulating hormones in cancer patients who were receiving palliative care during 4-62 months of follow-up. The entire cohort comprised 311 patients, ages 68 years +/- 3 years who were diagnosed with solid gastrointestinal tumors (84 colorectal tumors, 74 pancreatic tumors, 73 upper gastrointestinal tumors, 51 liver-biliary tumors, 3 breast tumors, 5 melanomas, and 21 other tumor types).

RESULTS

Decreased body weight was explained by loss of body fat, preferentially from the trunk, followed by leg tissue and arm tissue, respectively. Lean tissue (fat-free mass) was lost from arm tissue, whereas trunk and leg tissue compartments increased, all concomitant with declines in serum albumin, increased systemic inflammation (C-reactive protein, erythrocyte sedimentation rate), increased serum insulin, and elevated daily caloric intake; whereas serum insulin-like growth factor 1 (IGF-1), resting energy expenditure, and maximum exercise capacity remained unchanged in the same patients. Serum albumin levels (P < 0.001), whole body fat (P < 0.02), and caloric intake (P < 0.001) predicted survival, whereas lean tissue mass did not. Daily intake of fat and carbohydrate was more important for predicting survival than protein intake. Survival also was predicted by serum IGF-1, insulin, leptin, and ghrelin levels (P < 0.02 - P < 0.001). Serum insulin, leptin, and ghrelin (total) levels predicted body fat (P < 0.001), whereas IGF-1 and thyroid hormone levels (T3, free T3) predicted lean tissue mass (P < 0.01). Systemic inflammation primarily explained variation in lean tissue and secondarily explained loss in body fat. Depletion of lean arm tissue was related most to short survival compared with the depletion of lean leg and trunk tissue.

CONCLUSIONS

The current results demonstrated that body fat was lost more rapidly than lean tissue in progressive cancer cachexia, a phenomenon that was related highly to alterations in the levels of circulating classic hormones and food intake, including both caloric amount and diet composition. The results showed importance in the planning of efficient palliative treatment for cancer patients.

Habitual physical activity, anabolic hormones, and potassium content of fat-free mass in postmenopausal women

BACKGROUND

Total body potassium (TBK) is known to decline throughout adulthood. The relations between physical activity, age, anabolic hormones, and TBK have rarely been considered.

OBJECTIVE

We sought to describe the relation between habitual physical activity, age, serum estradiol, and insulin-like growth factor I (IGF-I) and TBK in postmenopausal women.

DESIGN

TBK, fat-free mass (FFM), moderate-to-vigorous-intensity physical activity (MVPA; assessed with use of a semistructured interview), and serum concentrations of estradiol, IGF-I, and IGF binding protein 3 (IGFBP-3) were quantified in 51 healthy white women aged 54-76 y.

RESULTS

The potassium content of FFM declined curvilinearly with age, indicating an accelerated loss of skeletal muscle after 65 y of age. With the data split into high (n = 25) and low (n = 26) MVPA groups, the active women had 6.5% more potassium per FFM than did their less-active counterparts (P < 0.01). In multiple regression analysis, MVPA was the major determinant of the potassium content of FFM (P = 0.02), such that an active 70-y-old had the potassium content value of a 55-y-old sedentary woman. Serum estradiol, IGF-I, and IGFBP-3 were not significant determinants of the potassium content of FFM.

CONCLUSIONS

These data suggest that 1) habitual physical activity can significantly influence FFM potassium content; 2) physical activity must, therefore, be considered if the effect of aging per se on TBK is to be clarified; and 3) MVPA, such as that pursued by the active women in the present study (eg, walking, dancing, floor exercises, and swimming), can assist in preventing sarcopenia in older women.