Endocrine changes in critically ill patients

Nocturnal Mean Arterial Pressure Rising Is Associated With Mortality in the Intensive Care Unit: A Retrospective Cohort Study

Background

Disrupted circadian rhythm of blood pressure is commonly observed in patients in the intensive care unit (ICU). This study assessed the association of nocturnal mean arterial pressure rising (NMAPR) with short‐ and long‐term mortality in critically ill adult patients.

Methods and Results

Adult patients with a complete record of mean arterial pressure monitoring during the first 24 hours of ICU stay in the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC‐II) database were included in this retrospective cohort study. All patients were divided into the non‐NMAPR group (≤1) or the NMAPR group (>1), according to the value of mean nighttime divided by daytime mean arterial pressure. The associations of NMAPR with ICU, hospital, 28‐day, and 1‐year mortality were assessed using multivariable logistic regression or a Cox proportional hazards model. Interaction and subgroup analyses were performed for those patients who had a first Sequential Organ Failure Assessment (SOFA) score of ≥8 or <8. The overall cohort comprised 5185 patients. The patients with NMAPR (n=1865) had higher ICU, hospital, 28‐day, and 1‐year mortality than the non‐NMAPR group (n=3320). After adjusting for covariates, the analysis showed that NMAPR was significantly associated with mortality in the ICU (odds ratio: 1.34; 95% CI, 1.10–1.65), in the hospital (odds ratio: 1.35; 95% CI, 1.12–1.63), at 28 days (hazard ratio: 1.27; 95% CI, 1.10–1.48), and at 1 year (hazard ratio: 1.24; 95% CI, 1.10–1.40). All results of the interaction analysis had no statistical significance, and similar results persisted in the patients with different SOFA scores.

Conclusions

NMAPR may aid in the early identification of critically ill patients at high risk of ICU, hospital, 28‐day, or 1‐year mortality.

Insulin-like Growth Factor I and its binding protein 3 in sepsis

OBJECTIVE

To investigate the Growth Hormone (GH)/Insulin-like Growth Factor-I (IGF-I) axis and identify the factors that determine IGF-I levels in adult septic patients of variable severity, i.e., with sepsis, severe sepsis or septic shock, in the acute phase of disease.

DESIGN

In 107 consecutive septic patients (44 with sepsis, 13 with severe sepsis, and 50 with septic shock), GH, IGF-I, Insulin-like Growth Factor Binding Protein-3 (IGFBP-3), insulin, cortisol, albumin, thyroid hormones, C-reactive protein and interleukin-6 serum levels were measured once within 48 h after onset of a septic episode. Twenty-nine healthy volunteers served as controls.

RESULTS

IGF-I and IGFBP-3 levels were decreased in patients with sepsis and severe sepsis (versus controls), decreasing further in patients with septic shock (versus sepsis). IGF-I levels were positively related to IGFBP-3, albumin, triiodothyronine and thyroxine, and inversely related to cortisol, sepsis severity, C-reactive protein, interleukin-6 and age. In multiple regression analysis, IGF-I levels were independently related to IGFBP-3 and albumin (lower in patients with decreased IGFBP-3 and albumin levels) (p<0.001 and p=0.01, respectively), and cortisol (lower in patients with increased cortisol levels) (p=0.04). IGFBP-3 accounted for most of the variance explained by the model (R(2)=0.519). GH levels were not related to IGF-I levels or mortality. IGF-I and IGFBP-3 levels were not associated with mortality.

CONCLUSIONS

The GH/IGF-I axis is severely disrupted in septic patients. IGFBP-3 is the major determinant of IGF-I levels.

Pathophysiological aspects of hyperglycemia in children with meningococcal sepsis and septic shock: a prospective, observational cohort study

INTRODUCTION

The objective of this study was to investigate the occurrence of hyperglycemia and insulin response in critically ill children with meningococcal disease in the intensive care unit of an academic children's hospital.

METHODS

Seventy-eight children with meningococcal disease were included. The group was classified into shock non-survivors, shock survivors and sepsis survivors. There were no sepsis-only non-survivors. The course of laboratory parameters during 48 hours was assessed. Insulin sensitivity and β-cell function on admission were investigated by relating blood glucose level to insulin level and C-peptide level and by homeostasis model assessment (HOMA) [β-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S)].

RESULTS

On admission, hyperglycemia (glucose >8.3 mmol/l) was present in 33% of the children. Shock and sepsis survivors had higher blood glucose levels compared with shock non-survivors. Blood glucose level on admission correlated positively with plasma insulin, C-peptide, cortisol, age and glucose intake. Multiple regression analysis revealed that both age and plasma insulin on admission were significantly related to blood glucose. On admission, 62% of the hyperglycemic children had overt insulin resistance (glucose >8.3 mmol/l and HOMA-%S <50%); 17% had β-cell dysfunction (glucose >8.3 mmol/l and HOMA-%B <50%) and 21% had both insulin resistance and β-cell dysfunction. Hyperglycemia was present in 11% and 8% of the children at 24 and 48 hours after admission, respectively.

CONCLUSIONS

Children with meningococcal disease often show hyperglycemia on admission. Both insulin resistance and β-cell dysfunction play a role in the occurrence of hyperglycemia. Normalization of blood glucose levels occurs within 48 hours, typically with normal glucose intake and without insulin treatment.

Is pituitary failure the real therapeutic target in septic shock?

Severe sepsis and septic shock have been part of intensivists' major challenges since the birth of the specialty. This clinical picture is followed by the development of a multiple organ failure syndrome. Our working hypothesis today is that multiple organ failures develop due to a systemic intravascular malignant inflammatory response. This article proposes an alternative understanding of the problem based on some of the recent data and understandings of non glycemic, non insulinemic endocrine dysfunction in severe sepsis and septic shock. Our presentation of selected literature supports the presence of a decreased production and activity in steroids, thyroid hormones, growth hormone, vasopressin and prolactin in septic shock. These hormones have important and synergistic functions. The disruption of which can lead to multiple organ failure in septic shock. Developing research focusing on the broad hypothalamic and pituitary functions could improve our understanding of metabolic derangements in severe sepsis and septic shock and thus provide new therapeutic options. These new therapies based on hormonal replacement are currently available at low cost and could improve outcomes.

Differential influence of open surgery and sepsis on the circulating insulin-like growth factors and their binding proteins as representative metabolic markers

OBJECTIVES

In critical illnesses and stress conditions many endocrine systems are disturbed. In the current study we determined the influence of open surgery, post-operative sepsis and its early therapy on the components of the insulin-like growth factor (IGF) system in patients with malignant gastric or pancreatic tumors.

DESIGN AND METHODS

Twenty-one patients and eighty-one age- and sex-matched healthy subjects were included in this study. IGF-I, IGF-II, IGF binding proteins (IGFBPs), cortisol, insulin and protein concentrations (total, albumin and IgG) were determined pre-operatively, post-operatively, when sepsis was diagnosed and 48 h after initiating therapy.

RESULTS

The concentrations of circulating IGF-I, IGF-II and IGFBP-3 were significantly lower in pre-operative patients compared to healthy subjects. Sepsis caused a further decrease in IGF-I and IGFBP-3 but an increase in IGFBP-1, IGFBP-2 and IGFBP-4 resulting in a redistribution of IGF molecules from ternary to binary complexes.

CONCLUSIONS

The presence of malignant gastric or pancreatic tumors followed by post-operative sepsis caused a serious misbalance in components of the IGF system which failed to recover during the time of our longitudinal study.

Combined growth hormone/insulin-like growth factor I in addition to glutamine-supplemented TPN results in net protein anabolism in critical illness

Protein loss leading to reduced lean body mass is recognized to contribute to the high levels of morbidity and mortality seen in critical illness. This prospective, randomized, controlled study compared the effects of conventional parenteral nutrition (TPN), glutamine-supplemented (0.4 g.kg-1.day-1) TPN (TPNGLN), and TPNGLN with combined growth hormone (GH, 0.2 IU.kg-1.day-1) and IGF-I (160 microg.kg-1.day-1) on protein metabolism in critical illness. Nineteen mechanically ventilated subjects [64 +/- 3 yr, body mass index (BMI) 23.8 +/- 1.3, kg/m2] were initially studied in the fasting state (study 1) and subsequently after 3 days of nutritional with/without hormonal support (study 2). All had recently been admitted to the ICU and the majority were postemergency abdominal surgery (APACHE II 17.5 +/- 1.0). Protein metabolism was assessed using a primed constant infusion of [1-13C]leucine. Conventional TPN contained mixed amino acids, Intralipid, and 50% dextrose. TPNGLN, unlike TPN alone, resulted in an increase in plasma glutamine concentration ( approximately 50%, P < 0.05). Both TPN and TPNGLN decreased the rate of protein breakdown (TPN 15%, P < 0.002; TPNGLN 16%, P < 0.05), but during these treatments the patients remained in a net negative protein balance. Combined treatment with TPNGLN + GH/IGF-I increased plasma IGF-I levels (10.3 +/- 0.8 vs. 48.1 +/- 9.1 nmol/l, study 1 vs. study 2, P < 0.05), and in contrast to therapy with nutrition alone, resulted in net protein gain (-0.75 +/- 0.14 vs. 0.33 +/- 0.12 g protein.kg-1.day-1, study 1 vs. study 2, P < 0.05). Therapy with GH/IGF-I + TPNGLN, unlike nutrition alone, resulted in net positive protein balance in a group of critically ill patients.

Reduced serum insulin-like growth factor-1 (IGF-1) and IGF-binding protein-3 levels in adults with inflammatory bowel disease

In the present study, the changes in circulating IGF-1 and its binding protein IGFBP-3 were determined in adult patients with active inflammatory bowel disease (IBD) in order to assess the effect of this inflammatory condition on the IGF system. IGF-1 and IGFBP-3, as well as interleukin-6 (IL-6) were measured in serum obtained from 22 consecutive newly diagnosed patients (mean age 41.3 years) with active IBD, including 10 patients with Crohn's disease (CD), and 12 with ulcerative colitis (UC). For comparison the same parameters were determined in 30 healthy volunteers matched for age, sex and Body Mass Index (BMI). Serum IGF-1 and IGFBP-3 levels were similar in the two subgroups of patients and the values from all patients were combined for comparison with those from the control group. The mean (+/- SD) serum IGF-1 concentration (178 +/- 91 ng/ml) in the patients with IBD was lower compared with that in the controls (227 +/- 79 ng/ml, P<0.035). Similarly, the mean IGFBP-3 concentration in the patients was lower than in the controls (1.6 +/- 0.6 ng/ml vs 3.2 +/- 0.7 ng/ml respectively, P<0.001), Serum IL-6 levels were higher in the patients compared with the controls (5.5 +/- 4.2 vs 0.65 +/- 0.11 pg/ml, P<0.0001). The reduced IGF-1 and IGFBP-3 levels in patients with active IBD suggest that this systemic inflammatory condition is associated with a degree of acquired GH resistance, possibly induced by inflammatory cytokines.