Association between the lactate/albumin ratio and mortality in pediatric septic shock patients with underlying chronic disease: retrospective pilot study.

BACKGROUND: We aimed to evaluate the ability of the lactate/albumin ratio to predict mortality in pediatric septic shock patients. METHODS: Retrospective analysis of the medical records of a pediatric intensive care unit. The study cohort comprised 90 pediatric septic shock patients admitted from February 2012 to May 2015. RESULTS: The serum lactate and albumin levels and lactate/albumin ratio were compared between survivors and non-survivors. We assessed whether the lactate/albumin ratio could be used to predict mortality. The 28-day hospital mortality was 26.7% (24/90). The lactate level was higher (2.5±2.2 vs. 8.1±5.1 mmol/L, P<0.001) and the albumin level was lower (2.9±0.5 vs. 2.7±0.5 mg/dL, P=0.063) in non-survivors than in survivors. The lactate/albumin ratio was 0.9±0.8 in survivors and 3.2±2.4 in non-survivors (P<0.001). According to the area under the receiver operating characteristic curve (AUC), the lactate/albumin ratio showed good discriminatory power for predicting mortality (AUC=0.867). A lactate/albumin ratio exceeding 1.016 led to a 7.636-fold increase in mortality. CONCLUSIONS: The lactate/albumin ratio is a useful predictor of mortality in pediatric septic shock patients.

Relationship of Physical Function to Single Muscle Fiber Contractility in Older Adults: Effects of Resistance Training With and Without Caloric Restriction.

BACKGROUND: Previous studies support beneficial effects of both resistance exercise training (RT) and caloric restriction (CR) on skeletal muscle strength and physical performance. The goal of this study was to determine the effects of adding CR to RT on single-muscle fiber contractility responses to RT in older overweight and obese adults. METHODS: We analyzed contractile properties in 1,253 single myofiber from muscle biopsies of the vastus lateralis, as well as physical performance and thigh muscle volume, in 31 older (65-80 years), overweight or obese (body mass index = 27-35 kg/m2) men (n = 19) and women (n = 12) who were randomly assigned to a standardized, progressive RT intervention with CR (RT+CR; n = 15) or without CR (RT; n = 16) for 5 months. RESULTS: Both interventions evoked an increase in force normalized to cross-sectional area (CSA), in type-I and type-II fibers and knee extensor quality. However, these improvements were not different between intervention groups. In the RT group, changes in total thigh fat volume inversely correlated with changes in type-II fiber force (r = -.691; p = .019). Within the RT+CR group, changes in gait speed correlated positively with changes in type-I fiber CSA (r = .561; p = .030). In addition, increases in type-I normalized fiber force were related to decreases in thigh intermuscular fat volume (r = -0.539; p = .038). CONCLUSION: Single muscle fiber force and knee extensor quality improve with RT and RT+CR; however, CR does not enhance improvements in single muscle fiber contractility or whole muscle in response to RT in older overweight and obese men and women.

Intramyocellular Lipid and Impaired Myofiber Contraction in Normal Weight and Obese Older Adults.

BACKGROUND: Evidence implicates the amount and location of fat in aging-related loss of muscle function; however, whether intramyocellular lipids affect muscle contractile capacity is unknown. METHODS: We compared both in vivo knee extensor muscle strength, power, and quality and in vitro mechanical properties of vastus lateralis single-muscle fibers between normal weight (NW) and obese older adults and determined the relationship between muscle lipid content (both intramuscular adipose tissue and intramyocellular lipids) and in vivo and in vitro muscle function in NW and obese individuals. RESULTS: The obese group had a greater percentage of type-I fibers compared to the NW group. The cross-sectional area of type-I fibers was greater in obese compared to NW; however, maximal shortening velocity of type-I fibers in the obese was slower compared to NW. Type-I and type-IIa fibers from obese group produced lower specific force than that of type-I and type-IIa fibers from the NW group. Normalized power was also substantially lower (~50%) in type-I fibers from obese adults. The intramyocellular lipids data showed that total lipid droplet area, number of lipid droplets, and area fraction were about twofold greater in type-I fibers from the obese compared to the NW group. Interestingly, a significant inverse relationship between average number of lipid droplets and single-fiber unloaded shortening velocity, maximal velocity, and specific power was observed in obese participants. Additionally, muscle echointensity correlated with single-fiber specific force. CONCLUSIONS: These data indicate that greater intramyocellular lipids are associated with slower myofiber contraction, force, and power development in obese older adults.