Que Lam

The past few years of research on leptin have provided important information on the link between metabolism and immune homeostasis. Adipocytes influence not only the endocrine system but also the immune response through several cytokine-like mediators known as adipokines, which include leptin. It is widely accepted that leptin can directly link nutritional status and pro-inflammatory T helper 1 immune responses, and that a decrease of leptin plasma concentration during food deprivation can lead to an impaired immune function. Additionally, several studies have implicated leptin in the pathogenesis of chronic inflammation, and the elevated circulating leptin levels in obesity appear to contribute to the low-grade inflammatory background which makes obese individuals more susceptible to increased risk of developing cardiovascular diseases, type II diabetes, or degenerative disease including autoimmunity and cancer. Conversely, reduced levels of leptin such as those found in malnourished individuals have been linked to increased risk of infection and reduced cell-mediated immune responses. We discuss here the functional influences of leptin in the physiopathology of inflammation, and the effects of leptin in the modulation of such responses.

BACKGROUND: Thiamine has a crucial role in energy production, and consequently thiamine deficiency (TD) has been associated with cardiac failure, neurological disorders, oxidative stress (lactic acidosis and sepsis) and refeeding syndrome (RFS). This review aims to explore analytical methodologies of thiamine compound quantification and highlight similarities, variances and limitations of current techniques and how they may be relevant to patients. CONTENT: An electronic search of Medline, PubMed and Embase databases for original articles published in peer-reviewed journals was conducted. MethodsNow was used to search for published analytical methods of thiamine compounds. Keywords for all databases included "thiamine and its phosphate esters", "thiamine methodology" and terms related to critical illness. Enquiries were also made to six external quality assurance (EQA) programme organisations for the inclusion of thiamine measurement. SUMMARY: A total of 777 published articles were identified; 122 were included in this review. The most common published method is HPLC with florescence detection. Two of the six EQA organisations include a thiamine measurement programme, both measuring only whole-blood thiamine pyrophosphate (TPP). No standard measurement procedure for thiamine compound quantification was identified. OUTLOOK: Overall, there is an absence of standardisation in measurement methodologies for thiamine in clinical care. Consequently, multiple variations in method practises are prohibiting the comparison of study results as they are not traceable to any higher order reference. Traceability of certified reference materials and reference measurement procedures is needed to provide an anchor to create the link between studies and help bring consensus on the clinical importance of thiamine.

OBJECTIVE Limited studies have examined the association between diabetes and HbA1c with postoperative outcomes. We investigated the association of diabetes, defined categorically, and the association of HbA1c as a continuous measure, with postoperative outcomes. RESEARCH DESIGN AND METHODS In this prospective, observational study, we measured the HbA1c of surgical inpatients age ≥54 years at a tertiary hospital between May 2013 and January 2016. Patients were diagnosed with diabetes if they had preexisting diabetes or an HbA1c ≥6.5% (48 mmol/mol) or with prediabetes if they had an HbA1c between 5.7 and 6.4% (39 and 48 mmol/mol). Patients with an HbA1c <5.7% (39 mmol/mol) were categorized as having normoglycemia. Baseline demographic and clinical data were obtained from hospital records, and patients were followed for 6 months. Random-effects logistic and negative binomial regression models were used for analysis, treating surgical units as random effects. We undertook classification and regression tree (CART) analysis to design a 6-month mortality risk model. RESULTS Of 7,565 inpatients, 30% had diabetes, and 37% had prediabetes. After adjusting for age, Charlson comorbidity index (excluding diabetes and age), estimated glomerular filtration rate, and length of surgery, diabetes was associated with increased 6-month mortality (adjusted odds ratio [aOR] 1.29 [95% CI 1.05–1.58]; P = 0.014), major complications (1.32 [1.14–1.52]; P < 0.001), intensive care unit (ICU) admission (1.50 [1.28–1.75]; P < 0.001), mechanical ventilation (1.67 [1.32–2.10]; P < 0.001), and hospital length of stay (LOS) (adjusted incidence rate ratio [aIRR] 1.08 [95% CI 1.04–1.12]; P < 0.001). Each percentage increase in HbA1c was associated with increased major complications (aOR 1.07 [1.01–1.14]; P = 0.030), ICU admission (aOR 1.14 [1.07–1.21]; P < 0.001), and hospital LOS (aIRR 1.05 [1.03–1.06]; P < 0.001). CART analysis confirmed a higher risk of 6-month mortality with diabetes in conjunction with other risk factors. CONCLUSIONS Almost one-third of surgical inpatients age ≥54 years had diabetes. Diabetes and higher HbA1c were independently associated with a higher risk of adverse outcomes after surgery.