Leptin and the post-operative inflammatory response. More insights into the correlation with the clinical course and glucocorticoid administration

Procalcitonin and C-reactive protein for diagnosing post-operative sepsis in neonates

AIM

To determine whether serum procalcitonin (PCT) or C-reactive protein (CRP) can diagnose post-operative sepsis among neonates undergoing major non-cardiac surgery.

METHODS

In this diagnostic study, we included neonates who underwent major non-cardiac surgery and were monitored for post-operative sepsis. We excluded pre-existing septic, inflammatory or life-threatening conditions. Subjects either had 'definite' (culture-positive, n = 14), 'probable' (clinical sepsis, culture-negative, n = 25) or no sepsis (n = 31). We measured serum CRP and PCT at 48 ± 6 h, 72 ± 6 h and 96 ± 6 h post-operatively and compared 'definite or probable sepsis' with 'no sepsis'.

RESULTS

Median (Q1, Q3) CRP (mg/L) in 'definite or probable' sepsis group was higher than 'no sepsis' at 72 h (91.48 (57.87, 143.50) vs. 51.32 (33.0, 80.1); P = 0.009) and 96 h (87.51 (45.19, 128.22) vs. 31.00 (25.3, 45.2); P < 0.001). Median (Q1, Q3) PCT (ng/mL) in 'definite or probable' sepsis was higher than 'no sepsis' at 72 h (4.22 (2.04, 12.73) vs. 1.78 (0.9, 6.4); P = 0.01) and 96 h (3.54 (1.96, 9.65) vs. 0.97 (0.4, 3.0); P < 0.001). Ninety-six-hour CRP and PCT cut-offs (based on Youden's index) were 74.16 mg/L and 1.65 ng/mL, respectively. If both CRP and PCT were positive, specificity was 100% (95% confidence interval: 88.78-100). If either one was positive, sensitivity was 88.89% (95% confidence interval: 73.94-96.89).

CONCLUSIONS

Septic neonates have significantly higher serum CRP and PCT compared to non-septic neonates at 72 and 96 h post-operatively. If both CRP and PCT are positive at 96 h after surgery, it has 100% specificity, and if either one is positive, 89% sensitivity.

Leptin's concentration in tears and dry eye: a clinical observational study

AIM

To investigate the concentration of leptin in tears and its correlation with dry eye symptoms and signs.

METHODS

The study enrolled individuals (n=39) responding to an advertising or dry eye patients (n=58) from the Ophthalmology Department. Tear samples were collected for leptin concentration measuring. Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), tear break up time (TBUT), cornea fluorescein staining, Schirmer test (ST) and impression cytology (IC) were assessed. Leptin concentration in tears of dry eye patients and healthy controls, and its correlation with clinical features of dry eye disease (DED) were analyzed.

RESULTS

Age, body mass index (BMI), OSDI scores and cornea fluorescein staining scores showed a negative correlation with leptin concentration in tears (r=-0.340, P=0.001; r=-0.332, P=0.001; r=-0.258, P=0.011; r=-0.424, P<0.001, respectively). ST showed positive correlation with leptin concentration in tears (r=0.206, P=0.045). No significant difference was observed in leptin concentration between dry eye patients and controls (P=0.682). Multivariate linear regression analysis revealed that dry eye, OSDI, corneal fluorescein staining scores and ST correlated with leptin concentration in tears.

CONCLUSION

This is the first study measuring leptin concentration in tears. The correlation between leptin concentration and DED symptoms and signs reveal that leptin level correlated with the dry eye, potentially contributing to repair of ocular damage and dry eye improvement.

Prophylactic corticosteroids for paediatric heart surgery with cardiopulmonary bypass

BACKGROUND

Corticosteroids are routinely given to children undergoing cardiac surgery with cardiopulmonary bypass (CPB) in an attempt to ameliorate the inflammatory response. Their use is still controversial and the decision to administer the intervention can vary by centre and/or by individual doctors within that centre.

OBJECTIVES

This review is designed to assess the benefits and harms of prophylactic corticosteroids in children between birth and 18 years of age undergoing cardiac surgery with CPB.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and Conference Proceedings Citation Index-Science in June 2020. We also searched four clinical trials registers and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included studies of prophylactic administration of corticosteroids, including single and multiple doses, and all types of corticosteroids administered via any route and at any time-point in the perioperative period. We excluded studies if steroids were administered therapeutically. We included individually randomised controlled trials (RCTs), with two or more groups (e.g. multi-drug or dose comparisons with a control group) but not 'head-to-head' trials without a placebo or a group that did not receive corticosteroids. We included studies in children, from birth up to 18 years of age, including preterm infants, undergoing cardiac surgery with the use of CPB. We also excluded studies in patients undergoing heart or lung transplantation, or both; studies in patients already receiving corticosteroids; in patients with abnormalities of the hypothalamic-pituitary-adrenal axis; and in patients given steroids at the time of cardiac surgery for indications other than cardiac surgery.

DATA COLLECTION AND ANALYSIS

We used the Covidence systematic review manager to extract and manage data for the review. Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We resolved disagreements by consensus or by consultation with a third review author. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We found 3748 studies, of which 888 were duplicate records. Two studies had the same clinical trial registration number, but reported different populations and interventions. We therefore included them as separate studies. We screened titles and abstracts of 2868 records and reviewed full text reports for 84 studies to determine eligibility. We extracted data for 13 studies. Pooled analyses are based on eight studies. We reported the remaining five studies narratively due to zero events for both intervention and placebo in the outcomes of interest. Therefore, the final meta-analysis included eight studies with a combined population of 478 participants. There was a low or unclear risk of bias across the domains. There was moderate certainty of evidence that corticosteroids do not change the risk of in-hospital mortality (five RCTs; 313 participants; risk ratio (RR) 0.83, 95% confidence interval (CI) 0.33 to 2.07) for children undergoing cardiac surgery with CPB. There was high certainty of evidence that corticosteroids reduce the duration of mechanical ventilation (six RCTs; 421 participants; mean difference (MD) 11.37 hours lower, 95% CI -20.29 to -2.45) after the surgery. There was high-certainty evidence that the intervention probably made little to no difference to the length of postoperative intensive care unit (ICU) stay (six RCTs; 421 participants; MD 0.28 days lower, 95% CI -0.79 to 0.24) and moderate-certainty evidence that the intervention probably made little to no difference to the length of the postoperative hospital stay (one RCT; 176 participants; mean length of stay 22 days; MD -0.70 days, 95% CI -2.62 to 1.22). There was moderate certainty of evidence for no effect of the intervention on all-cause mortality at the longest follow-up (five RCTs; 313 participants; RR 0.83, 95% CI 0.33 to 2.07) or cardiovascular mortality at the longest follow-up (three RCTs; 109 participants; RR 0.40, 95% CI 0.07 to 2.46). There was low certainty of evidence that corticosteroids probably make little to no difference to children separating from CPB (one RCT; 40 participants; RR 0.20, 95% CI 0.01 to 3.92). We were unable to report information regarding adverse events of the intervention due to the heterogeneity of reporting of outcomes. We downgraded the certainty of evidence for several reasons, including imprecision due to small sample sizes, a single study providing data for an individual outcome, the inclusion of both appreciable benefit and harm in the confidence interval, and publication bias.

AUTHORS' CONCLUSIONS

Corticosteroids  probably do not change the risk of mortality for children having heart surgery using CPB at any time point. They probably reduce the duration of postoperative ventilation in this context, but have little or no effect on the total length of postoperative ICU stay or total postoperative hospital stay. There was inconsistency in the adverse event outcomes reported which, consequently, could not be pooled. It is therefore impossible to provide any implications and policy-makers will be unable to make any recommendations for practice without evidence about adverse effects. The review highlighted the need for well-conducted RCTs powered for clinical outcomes to confirm or refute the effect of corticosteroids versus placebo in children having cardiac surgery with CPB. A core outcome set for adverse event reporting in the paediatric major surgery and intensive care setting is required.

Dietary inflammatory index as a potential determinant of a length of hospitalization among surgical patients treated for colorectal cancer

Background/objectives:

Inflammation is a central process responsible for health outcomes among surgical patients. Immunonutrition has been investigated as a promising modifying factor; however, inflammatory properties of habitual diet have not yet been investigated. The purpose of this study was to describe inflammatory properties of diet measured by the dietary inflammatory index (DII) among surgical patients treated for colorectal cancer and to link inflammatory properties of habitual diet with a duration of hospitalization.

Subjects/methods:

A follow-up study among colorectal cancer patients treated surgically was performed in Krakow, Poland. In total, 689 patients were recruited for the study. Habitual diet was assessed using a standardized semiquantitative food frequency questionnaire. Overall, 23 dietary items (including macro-and micronutrients) were used to calculate individuals' DII. Gender, age, marital status, body mass index, smoking status, lifetime physical activity, taking vitamin supplements, number of chronic diseases, cancer site, Duke's staging and surgery type were considered as potential covariates.

Results:

Participants were aged 58 years, with the average hospitalization time of 11 days. Higher DII (meaning diet with higher anti-inflammatory properties) was negatively associated with the duration of hospitalization (univariable linear regression: b=−0.59; P=0.005). Multivariable logistic regression has shown the decrease of the risk of longer stays (>7 days) among patients with the DII >−4.25, but only among younger (⩽60 years) patients, irrespective of Duke's staging.

Conclusions:

The DII might be used as a potential predictor of longer hospitalization among colorectal cancer patients treated surgically. The study provides evidence for the role of dietary-related low-grade inflammation among surgical patients.

The reward value of sucrose in leptin-deficient obese mice

Leptin-deficient patients report higher "liking" ratings for food, and leptin replacement therapy normalizes these ratings even before weight loss is achieved. Since animals cannot report their ratings, we studied the relationship between leptin and food reward in leptin-deficient ob/ob mice using a optogenetic assay that quantifies the reward value of sucrose. In this assay, mice chose between one sipper dispensing the artificial sweetener sucralose coupled to optogenetic activation of dopaminergic (DA) neurons, and another sipper dispensing sucrose. We found that the reward value of sucrose was high under a state of leptin deficiency, as well as at a dose of leptin that does not suppress food intake (12.5 ng/h). Treatment with higher doses of leptin decreased the reward value of sucrose before weight loss was achieved (100 ng/h), as seen in leptin-deficient patients. These results phenocopy in mice the behavior of leptin-deficient patients.