Processing Human Milk to Increase Nutrient Density for Preterm Infants.

BACKGROUND: Human milk is the optimal food for newborns. Choices to feed preterm infants in neonatal intensive care units are mother's milk, donor milk, or formula. Preterm infants have better tolerance for human milk, but the lower caloric density of donor milk might not meet preterm infant growth needs. Preterm infants have higher protein and energy requirements with a limited stomach capacity. Therefore, there is a need for human milk with increased nutrient density. RESEARCH AIM: To concentrate donor milk to have a higher caloric and protein density while avoiding side effects of high osmolality by precipitating lactose at low temperatures. METHODS: We investigated the results of volume reduction and lactose removal processes on the lactose, protein, osmolality, and viscosity of human milk. Donor milk was obtained from WakeMed Mothers' Milk Bank. Homogenization and evaporative condensation were applied to samples (N = 36) before they were stored frozen overnight, followed by refrigerated centrifugation for lactose removal at 0 °C. Supernatants were separated and compared to the composition of controls. RESULTS: A significant reduction of lactose (SW = -262, p < .0001) and osmolality (SW = -211.5 p < .01) was achieved in the concentrated milk without a significant protein loss from centrifugation (SW = -44.5, p = .49). A 30%-40% volume reduction is within the American Academy of Pediatrics recommended osmolality for infant feeding. CONCLUSION: Concentrating human milk in a milk bank setting for feeding preterm infants might be a simple and low-cost process to achieve a product with higher nutrient density and no non-human components.

The Relationship Between Myostatin, Inflammatory Markers, and Sarcopenia in Patients With Chronic Kidney Disease.

OBJECTIVE: To determine the prevalence of sarcopenia in patients with chronic kidney disease (CKD), investigate the relationship of the serum myostatin level with sarcopenia and inflammatory markers. METHODS: The study was conducted with four patient groups: renal transplantation (TX), stage 3-5 non-dialysis-dependent CKD (NDD-CKD), hemodialysis (HD), and peritoneal dialysis (PD). Laboratory parameters, serum myostatin, C-reactive protein, and interleukin-6 levels were studied. Body composition was estimated using a multifrequency bioimpedance analysis. Handgrip strength (HGS) was evaluated with a handgrip dynamometer. The HGS and appendicular skeletal muscle index measurements were used to determine sarcopenia presence. RESULTS: The study included 130 patients (72 [55%] male patients). The patient distribution in groups was as follows: 37 in HD, 28 in PD, 37 in renal TX, and 28 in NDD-CKD. The highest level of myostatin was measured in the HD group, and the lowest in the TX group (P < .001). The HGS measurement in the PD group was significantly lower than that in the TX group (P = .025). The myostatin was negatively correlated with HGS, albumin, estimated glomerular filtration rate, and Kt/Vurea. However, myostatin had no correlation with inflammatory markers or appendicular skeletal muscle index. Sarcopenia was present in 37 (29%) patients: 15 (40%) in the HD group, nine (32%) in NDD-CKD, seven (25%) in PD, and six (16%) in TX. When the patients with and without sarcopenia were compared, only myostatin was higher in the former (P = .045). As a result of multivariate analysis, myostatin was the only independent factor which predicts sarcopenia (odds ratio: 1.002, 95% confidence interval: 1.001-1.005, P = .048). CONCLUSION: To prevent devastating events associated with sarcopenia in patients with CKD, renal transplantation seems to be the best treatment solution. For the early recognition of sarcopenia, the measurement of the serum myostatin level may be a promising diagnostic approach.

Novel inflammatory marker in dialysis patients: YKL-40.

YKL-40 has been introduced as a marker of inflammation in different clinical situations. The association between YKL-40 and inflammation in chronic renal failure patients has not been researched currently. The objectives of this study were to establish serum YKL-40 concentrations in dialysis patients with chronic renal failure compared to healthy subjects and to explore its relationships with a proinflammatory cytokine, interleukine-6 (IL-6) and an acute phase mediator, high sensitivity C-reactive protein (hs-CRP). The study population included hemodialysis patients (N = 43; mean age of 40.9 ± 14.5), peritoneal dialysis patients (N = 38; mean age of 45.8 ± 13.7) and healthy subjects (N = 37; mean age of 45.5 ± 10.6). Serum concentrations of YKL-40, IL-6, hs-CRP and routine laboratory measures were evaluated. Compared to the healthy subjects, hemodialysis and peritoneal dialysis patients had higher concentrations of YKL-40, IL-6, hs-CRP, as well as lower concentrations of hemoglobin, serum albumin and high density lipoprotein-cholesterol (P < 0.001). YKL-40 concentrations were positively correlated with serum creatinine (P < 0.001, r = 0.495), IL-6 (P < 0.001, r = 0.306), hs-CRP (P = 0.001, r = 0.306) levels and inversely correlated with hemoglobin (P = 0.002, r = -0.285), serum albumin (P < 0.001, r = -0.355) and high density lipoprotein-cholesterol (P = 0.001, r = -0.306). In multivariate regression analysis YKL-40 was associated with creatinine, serum albumin and hs-CRP concentrations after adjustments with covariates. Dialysis patients with chronic renal failure have elevated serum YKL-40 concentrations. Associations with standard inflammatory parameters suggest that YKL-40 might be a novel inflammatory marker in this population.