Lindsay D. Plank

Body size, body composition and fat distribution: comparative analysis of European, Maori, Pacific Island and Asian Indian adults.

Although there is evidence that Asian Indians, Polynesians and Europeans differ in their body fat (BF)-BMI relationships, detailed comparative analysis of their underlying body composition and build characteristics is lacking. We investigated differences in the relationships between body fatness and BMI, fat distribution, muscularity, bone mineral mass, leg length and age-related changes in body composition between these ethnic groups. Cross-sectional analysis of 933 European, Maori, Pacific Island and Asian Indian adult volunteers was performed for total and percentage of BF, abdominal fat, thigh fat, appendicular muscle mass, bone mineral content and leg length measured by dual-energy X-ray absorptiometry. Asian Indian men and women (BMI of 24 and 26 kg/m2, respectively) had the same percentage of BF as Europeans with a BMI of 30 kg/m2 or Pacific men and women with BMI of 34 and 35 kg/m2, respectively. Asian Indians had more fat, both total and in the abdominal region, with less lean mass, skeletal muscle and bone mineral than all other ethnic groups. Leg length was relatively longer in Pacific men and Asian and Pacific women than in other ethnic groups. In Asian Indians, abdominal fat increased with increasing age, while the percentage of BF showed little change. In the other ethnic groups, both abdominal and total BF increased with age. In conclusion, ethnic differences in fat distribution, muscularity, bone mass and leg length may contribute to ethnic-specific relationships between body fatness and BMI. The use of universal BMI cut-off points may not be appropriate for the comparison of obesity prevalence between ethnic groups.

Sequential changes in the metabolic response in severely septic patients during the first 23 days after the onset of peritonitis.

OBJECTIVE To quantify the sequential changes in metabolic response occurring in patients with severe sepsis after the onset of peritonitis. SUMMARY BACKGROUND DATA Understanding the changes in energy expenditure and body composition is essential for the optimal management of severely septic patients; however, they have not been quantified in the context of modern surgical care. METHODS Twelve patients with severe sepsis secondary to peritonitis (median APACHE II score = 21.5) had measurements of energy expenditure and body composition as soon as they were hemodynamically stable and 5, 10, and 21 days later. Sequential measurements of acute-phase proteins and cytokine responses were also made. RESULTS Resting energy expenditure rose to 49% above predicted and remained elevated throughout the study period. Total energy expenditure was 1.25 x resting energy expenditure. Body fat was oxidized when energy intake was insufficient to achieve energy balance. There was a positive fluid balance of 12.5 1 over the first 2 days after onset of sepsis; thereafter, body water changes closely paralleled body weight changes and were largely accounted for by changes in extracellular water. During the 21 -day study period, there was a loss of 1.21 kg (13%) of total body protein. During the first 10 days, 67% of the protein lost came from skeletal muscle, but after this time it was predominantly from viscera. Intracellular potassium levels were low but did not deteriorate further after hemodynamic stability had been reached. There was a reprioritization of hepatic protein synthesis that was obligatory and independent of changes in total body protein. The cytokine responses demonstrated the complexity, redundancy, and overlap of mediators. CONCLUSIONS The period of hypermetabolism in severely septic patients is similar to that previously described, but the fluid changes are larger and the protein loss is greater. Protein loss early on is predominantly from muscle, thereafter from viscera. Fat loss can be prevented and cell function preserved once hemodynamic stability is achieved.

Optimal protein requirements during the first 2 weeks after the onset of critical illness.

OBJECTIVE To obtain optimal protein requirements in critically ill sepsis or trauma patients during the first 2 wks after admission to the intensive care unit. DESIGN Retrospective study. SETTING Department of critical care medicine at a teaching hospital. PATIENTS Immediate posttrauma patients or severely septic patients. INTERVENTIONS In vivo neutron activation analysis was used to measure changes in total body protein over a 10-day period which began as soon as the patients were hemodynamically stable. The patients (trauma, n=18; sepsis, n=5) were divided into three groups according to the average daily protein intakes. Because the patients were overhydrated (approximately 10 L) and had variable amounts of body fat, the protein intakes were indexed to normally hydrated (corrected) fat-free mass (FFMc): Groups A, B, and C received an average of 1.1, 1.5, and 1.9 g/kg FFMc/day protein, respectively. MEASUREMENTS AND MAIN RESULTS Overall, the average loss of total body protein was 1.2=0.7 (SD) kg. Changes in total body protein were significantly (p=.011) different between the three groups. The loss of body protein was significantly more in group A compared with groups B (p=.013) and C (p=.023). When the protein intake was increased from 1.1 g/kg FFMc/day to 1.5 g/kg FFMc/day, protein loss was halved. Further increase in protein intake up to 1.9 g/kg FFMc/day resulted in no further improvement. An intake of 1.5 g/kg FFMc/day was equivalent to 1.0 g/day/kg of body weight measured at the beginning of the study. CONCLUSIONS Current recommended protein requirements of 1.2 to 2.0 g/kg of body weight/day are excessive if they are indexed to the body weight measured soon after the onset of critical illness. Because individual patients have varying degrees of overhydration early in the illness onset, we suggest that the intensivist should obtain information on preillness body weight and prescribe 1.2g of protein/kg body weight/day. If information is not available, 1.0g of protein/day/kg of measured body weight will give a fair approximation to optimal protein requirements.

Body size and composition in polynesians.

OBJECTIVES: To compare the relationship between body size and body composition in New Zealanders of Polynesian and European descent and to develop specific regression equations for fat mass for Polynesians.SUBJECTS: 189 Maori (93 males, 96 females), 185 Samoans (88 males, 97 females) and 241 Europeans (89 males, 152 females) aged 20–70 y.MEASUREMENTS: Height, weight, four skinfold thicknesses, bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA).RESULTS: At higher body mass index levels, Polynesians (Maori and Samoans combined) had a significantly higher ratio of lean mass:fat mass compared with Europeans. Four multiple regression equations incorporating resistance and reactance, height and weight, sum of four skinfolds or sum of two skinfolds were developed in two-thirds of the Polynesian participants using DXA fat mass as the dependent variable. In the remaining one-third of participants, the mean difference between fat mass predicted by these equations (r2 range 0.89–0.93) and DXA fat mass ranged from −0.06 to +0.25 kg (s.d. −3.67 to +3.71 kg).CONCLUSION: At higher BMI levels, Polynesians were significantly leaner than Europeans, implying the need for separate BMI definitions of overweight and obesity for Polynesians. The regression equations using BIA, height and weight or skinfold thicknesses were good predictors of body composition in Polynesians.

Sequential changes in the metabolic response in critically injured patients during the first 25 days after blunt trauma.

BACKGROUND Understanding the changes in energy expenditure and body composition is essential for the optimal management of the critically injured, yet these changes have not been quantified within the current context of trauma care. METHODS Ten critically injured patients (median Injury Severity Score = 35) had measurements of energy expenditure and body composition as soon as they were hemodynamically stable and then every 5 days for 21 days. RESULTS Resting energy expenditure rose to 55% above predicted and remained elevated throughout the study period. Total energy expenditure was 1.32 X resting energy expenditure. Body fat was oxidized when energy intake was insufficient (r=-0.830, p<0.02). Body water changes closely paralleled body weight changes and were largely accounted for by changes in extracellular water. Over the 21-day study period, there was a loss of 1.62 kg (16%) of total body protein (p<0.0002), of which 1.09 kg (67%) came from skeletal muscle. Intracellular potassium was low (133 +/- 3 mmol/L, p<0.02) but did not deteriorate further after hemodynamic stability had been reached. CONCLUSIONS These results show that the period of hypermetabolism lasts longer and the protein loss is greater in critically injured patients than previously thought. Most, but not all, the protein is lost from muscle. Fat loss can be prevented and cell composition preserved once hemodynamic stability is achieved.

Components of energy expenditure in patients with severe sepsis and major trauma: a basis for clinical care.

OBJECTIVE To obtain accurate values for the components of energy expenditure in critically ill patients with sepsis or trauma during the first 2 wks after admission to the intensive care unit. DESIGN Prospective study. SETTING Critical care unit and university department of surgery in a single tertiary care center. PATIENTS Twelve severely septic (median Acute Physiology and Chronic Health Evaluation II Score, 23; range, 15 to 34) and 12 major trauma patients (median Injury Severity Score, 33.5; range, 26 to 50). INTERVENTIONS Total body fat, total body protein, and total body glycogen were measured as soon as hemodynamic stability had been reached and repeated 5 and 10 days later. Resting energy expenditure (REE) was measured daily by indirect calorimetry. MEASUREMENTS AND MAIN RESULTS Changes in total body fat, total body protein, and total body glycogen in critically ill patients provide data for the accurate construction of an energy balance. Energy intake minus energy balance gives a direct measurement of total energy expenditure (TEE) and, when combined with measurements of REE, activity energy expenditure can be obtained. TEE, REE, and activity energy expenditure were calculated for two sequential 5-day study periods. REE progressively increased during the first week after the onset of severe sepsis or major trauma, peaking during the second week at 37 +/- 6% (SEM) and 60 +/- 13% greater than predicted, respectively. For both the sepsis and trauma patients, TEE was significantly higher during the second week than during the first week (3257 +/- 370 vs. 1927 +/- 370 kcal/day, p < .05, in sepsis; 4123 +/- 518 vs. 2380 +/- 422 kcal/day, p < .05, in trauma). During the first week after admission to the hospital, TEE in sepsis and trauma patients, respectively, averaged 25 +/- 5 and 31 +/- 6 kcal/kg of body weight/day, and during the second week, 47 +/- 6 and 59 +/- 7 kcal/kg/day (p < .03, for comparison of first and second weeks). For the first week, the ratio of TEE to REE was 1.0 +/- 0.2 and 1.1 +/- 0.2 but during the second week rose to 1.7 +/- 0.2 and 1.8 +/- 0.2 in patients with sepsis (p < .05, for comparison of weeks) and trauma (p = .09), respectively. CONCLUSIONS Total energy expenditure is maximal during the second week after admission to the critical care unit, reaching 50 to 60 kcal/kg/day.

Sequential metabolic changes following induction of systemic inflammatory response in patients with severe sepsis or major blunt trauma.

Abstract. We have recently completed studies in critically ill patients with severe sepsis or major trauma that investigated sequential changes in the metabolic response following admission to the intensive care unit. Protein, water, and energy metabolism were measured using in vivo neutron activation analysis, tracer dilution, dual-energy x-ray absorptiometry, and indirect calorimetry. Over the 3-week study period both groups of patients lost 13% of their total body protein. The severe sepsis patients retained twice the volume of fluid of those with major trauma, and the return to normal hydration in the sepsis group was correspondingly prolonged, especially for those in the elderly age group. In both groups of patients resting energy expenditure increased progressively over the first week to around 40% above normal and was still elevated 3 weeks from onset of illness. A twofold increase in total energy expenditure occurred in both groups of patients between the first and second weeks of critical care admission. The prolonged hypermetabolism throughout the study period was not reflected in the concentrations of circulating proinflammatory cytokines, which fell rapidly over the first week. The pattern of changes seen in plasma proinflammatory and antiinflammatory cytokine concentrations is similar for sepsis and trauma. The remarkably similar metabolic sequelae seen in critically ill patients following the onset of severe sepsis or major trauma may constitute a universal response to the induction of the systemic inflammatory response syndrome.

Estimation of body fatness from body mass index and bioelectrical impedance: comparison of New Zealand European, Maori and Pacific Island children

Objective: To compare percentage body fat (%BF) for a given body mass index (BMI) among New Zealand European, Maori and Pacific Island children. To develop prediction equations based on bioimpedance measurements for the estimation of fat-free mass (FFM) appropriate to children in these three ethnic groups.Design: Cross-sectional study. Purposive sampling of schoolchildren aimed at recruiting three children of each sex and ethnicity for each year of age. Double cross-validation of FFM prediction equations developed by multiple regression.Setting: Local schools in Auckland.Subjects: Healthy European, Maori and Pacific Island children (n=172, 83 M, 89 F, mean age 9.4±2.8(s.d.), range 5–14 y).Measurements: Height, weight, age, sex and ethnicity were recorded. FFM was derived from measurements of total body water by deuterium dilution and resistance and reactance were measured by bioimpedance analysis.Results: For fixed BMI, the Maori and Pacific Island girls averaged 3.7% lower %BF than European girls. For boys a similar relation was not found since BMI did not significantly influence %BF of European boys (P=0.18). Based on bioimpedance measurements a single prediction equation was developed for all children: FFM (kg)=0.622 height (cm)2/resistance+0.234 weight (kg)+1.166, R 2=0.96, s.e.e.=2.44 kg. Ethnicity, age and sex were not significant predictors.Conclusions: A robust equation for estimation of FFM in New Zealand European, Maori and Pacific Island children in the 5–14 y age range that is more suitable than BMI for the determination of body fatness in field studies has been developed.Sponsorship: Maurice and Phyllis Paykel Trust, Auckland University of Technology Contestable Grants Fund and the Ministry of Health.

Nocturnal nutritional supplementation improves total body protein status of patients with liver cirrhosis: A randomized 12‐month trial

Patients with liver cirrhosis exhibit early onset of gluconeogenesis after short‐term fasting. This accelerated metabolic reaction to starvation may underlie their increased protein requirements and muscle depletion. A randomized controlled trial was conducted to test the hypothesis that provision of a late‐evening nutritional supplement over a 12‐month period would improve body protein stores in patients with cirrhosis. A total of 103 patients (68 male, 35 female; median age 51, range 28–74; Child‐Pugh grading: 52A, 31B, 20C) were randomized to receive either daytime (between 0900 and 1900 hours) or nighttime (between 2100 and 0700 hours) supplementary nutrition (710 kcal/day). Primary etiology of liver disease was chronic viral hepatitis (67), alcohol (15), cholestatic (6), and other (15). Total body protein (TBP) was measured by neutron activation analysis at baseline, 3, 6, and 12 months. Total daily energy and protein intakes were assessed at baseline and at 3 months by comprehensive dietary recall. As a percentage of values predicted when well, TBP at baseline was similar for the daytime (85 ± 2[standard error of the mean]%) and nighttime (84 ± 2%) groups. For the nighttime group, significant increases in TBP were measured at 3 (0.38 ± 0.10 kg, P = 0.0004), 6 (0.48 ± 0.13 kg, P = 0.0007), and 12 months (0.53 ± 0.17 kg, P = 0.003) compared to baseline. For the daytime group, no significant changes in TBP were seen. Daily energy and protein intakes at 3 months were higher than at baseline in both groups (P < 0.0001), and these changes did not differ between the groups. Conclusion: Provision of a nighttime feed to patients with cirrhosis results in body protein accretion equivalent to about 2 kg of lean tissue sustained over 12 months. This improved nutritional status may have important implications for the clinical course of these patients. (HEPATOLOGY 2008.)

Effect of a chimeric antibody to tumor necrosis factor-alpha on cytokine and physiologic responses in patients with severe sepsis-a randomized, clinical trial

OBJECTIVES Tumor necrosis factor (TNF)-alpha appears central to the pathogenesis of severe sepsis, but aspects of the cytokine cascade and the link to physiologic responses are poorly defined. We hypothesized that a monoclonal antibody to TNF-alpha given early in the course of severe sepsis would modify the pattern of systemic cytokine release and, as a consequence, resuscitation fluid requirements, net proteolysis, and hypermetabolism would be reduced. DESIGN Randomized, double-blind, placebo-controlled trial. SETTING Critical Care Unit and University Department of Surgery in a single tertiary care center. PATIENTS Fifty-six patients (from 92 eligible patients) with severe sepsis. Twenty-eight patients were randomized to treatment, and were comparable with the placebo group for age, gender, race, Acute Physiology and Chronic Health Evaluation II score, and site and type of infection. INTERVENTIONS A 300-mg single dose of cA2 (a chimeric neutralizing antibody to TNF-alpha) was given intravenously within 12 hrs of the onset of severe sepsis. Standard surgical and intensive care therapy was otherwise delivered. MEASUREMENTS AND MAIN RESULTS Plasma concentrations of TNF-alpha, interleukin (IL)-1beta IL-6, IL-8, IL-10, soluble 75-kilodalton TNF-alpha receptor (sTNFR-75), and IL-1beta receptor antagonist (IL-1ra) were measured by sandwich enzyme-linked immunosorbent assay before cA2 infusion, 8 hrs later, and then daily for a minimum of 4 days. Sequential changes in total body protein, body water spaces, and resting energy expenditure over 21 days were measured, as soon as patients achieved hemodynamic stability, by in vivo neutron activation analysis, tritium and bromide dilution, and indirect calorimetry, respectively. Twenty-one patients died, ten having received cA2. Suppression of measurable TNF-alpha was observed at 8 hrs with subsequent rebound by 24 hrs after cA2 treatment. The concentrations of other cytokines were high, were not reduced by intervention, and decreased logarithmically over 5 days. Both groups reached hemodynamic stability at similar times (57.5 +/- 11.8 hrs in controls vs. 58.6 +/- 9.2 hrs in the cA2 group) and following similar volumes of infused fluids (29.1 +/- 3.4 L vs. 28.9 +/- 4.4 L). No differences in net proteolysis, resolution of body water expansion, or alteration in resting energy expenditure were demonstrated. CONCLUSION A single dose of cA2 did not alter the overall pattern of cytokine activation or the profound derangements in physiologic function that accompany severe sepsis.