Polly Lenssen

Effects of resistive exercise on skeletal muscle in marrow transplant recipients receiving total parenteral nutrition

Skeletal muscle protein loss occurs during marrow transplantation despite total parenteral nutrition. To determine if muscle atrophy could be minimized with exercise therapy, 30 patients undergoing marrow transplantation for acute leukemia completed a prospective randomized trial to receive: (1) no therapy (controls), (2) physical therapy thrice weekly (PT3), or (3) physical therapy five times weekly (PT5). Patients were studied through 35 days posttransplant. Muscle protein status and turnover was assessed by weekly nitrogen balance, and creatinine and 3-methylhistidine excretion. Results favored a muscle protein-sparing effect of exercise, as a significant decrease in creatinine excretion in controls only suggested muscle protein loss associated with inactivity. Changes in arm muscle area correlated with energy, but not protein intake. Large individual variation, inadequate nutritional support and differences in admission arm muscle area may have clouded these results.

Body composition changes in marrow transplant recipients receiving total parenteral nutrition

Nine patients with acute lymphocytic leukemia in remission, aged 12–35 years, undergoing allogeneic bone marrow transplantation (BMT) were studied for changes in body fluid balance and body composition. Body composition and fluids were assessed the first 4 weeks following BMT, using isotope dilution and anthropometry. Oral and parenteral nutrient intakes were recorded daily. Tracer dilution techniques were used to assess body fluid volumes and estimate body cell, lean body, and body fat masses. Body cell mass was lost (mean −1.62 kg, P < 0.05) without significant changes in body fat or lean body masses. There was an expansion of the extracellular fluid compartment (mean +0.8 l, P < 0.05) and a loss in the intracellular fluid compartment (mean −1.3 l, P < 0.05) with little change in total body water volume. Changes in body weight correlated poorly with body cell mass or fluid volume changes. Change in arm muscle area correlated well with changes in body cell mass (r = 0.61, P < 0.05) and lean body mass (r = 0.68, P < 0.05), while that of arm fat area did not reflect its isotope dilution‐derived counterpart. Instead, the change in arm fat area was related to shifts in fluid compartments. Prealbumin decreased significantly (mean −9.3 mg/dl, P < 0.05), while albumin decreased slightly (mean −0.1 mg/dl), and both were related to changes in body cell mass. Nitrogen balance was negative throughout the study and the overall mean was related to the change in body cell mass (r = 0.60, P < 0.05). Calorie and protein intakes were not associated with the changes in body composition, implying other causal factors.

Intravenous Branched Chain Amino Acid Trial in Marrow Transplant Recipients

Branched chain amino acids (BCAA) improve nitrogen balance and end-organ function in surgical patients, but are untested in marrow transplant recipients. We compared nitrogen balance, urinary 3-methylhistidine-to-creatinine ratio, upper arm anthropometry, serum prealbumin, and day to peripheral engraftment in a randomized, double-blinded trial between 45% (high-leucine) and 23% BCAA intravenous solutions in 40 adult leukemia patients for 1 month following allogeneic marrow transplantation. Nutritional support, provided at approximately 30 nonprotein calories/kg and 0.21 g nitrogen/kg ideal weight, did not differ between groups. Despite greater nitrogen loss and muscle breakdown evidenced by increased 3-methylhistidine-to-creatinine ratio and loss of arm muscle area by study end in the 45% BCAA, no statistical differences were observed when nitrogen balance was compared by week and within stress level as defined by organ and infectious complications. It is likely the patients in the 45% BCAA experienced greater metabolic stress by study end. Serum prealbumin and day posttransplant to peripheral engraftment also did not differ between groups. The chances (power) of this study exceeded 85% in detecting a difference in nitrogen balance of 2.5 g during study week 1 and 4.0 g during week 2. The power during week 3 was 77% for detecting a difference of 4.0 g, and it is unlikely that the true difference exceeds this magnitude. Thus, we did not find any evidence that intravenous BCAA-enriched solutions improved nitrogen balance during the first month after marrow transplantation.

Nutrient Support in Hematopoietic Cell Transplantation

High-dose cytoreduction and hematopoietic stem cell infusion form the basis for treatment of hematologic cancers, defects or failure of hematopoiesis, and some solid tumors. As an antitumor therapy, allogeneic hematopoietic cell transplantation (HCT) is superior to autologous HCT by induction of a graft-vs-tumor effect. However, recipients of allografts suffer higher transplant-related mortality owing to graft-vs-host disease (GVHD). Nutrition support research must recognize that HCT is a heterogeneous modality whose short and long-term outcomes are affected by transplant type, preparative regimens, diagnosis, disease stage, age, and nutritional status. The field of HCT will diversify further as lower dose cytoreduction and mixed chimerism grafts allow expansion of the technique to older patients and to other diseases.