Single breath counting technique to assess pulmonary function: a systematic review and meta-analysis.

Pulmonary function is usually assessed by measuring Vital Capacity (VC) using equipment such as a spirometer or ventilometer, but these are not always available to the population, as they are relatively expensive tests, difficult to transport and require trained professionals. However, the single breath counting technique (SBCT) appears as a possible alternative to respiratory function tests, to help in the pathophysiological understanding of lung diseases. The objective is to verify the applicability of the SBCT as a parameter for evaluating VC. This is a systematic review registered in the International Prospective Register of Systematic Reviews (CRD42023383706) and used for PubMed®, Scientific Electronic Library Online, LILACS, EMBASE, and Web of Science databases of articles published until January 2023. Methodological quality regarding the risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 and National Institutes of Health tools. Eleven of a total of 574 studies were included, of these, nine showed a correlation between VC and SBCT (weak in healthy, moderate in neuromuscular and strong in hospitalized patients). One study of hospitalized patients accurately identified a count value of 21 for a VC of 20 ml kg-1(Sensitivity = 94% and Specificity = 77%), and another estimated a count lower than 41 for a VC below 80% of predicted in patients with neuromuscular dystrophy (Sensitivity = 89% and Specificity = 62%), and another showed good intra and inter-examiner reproducibility in young, adult, and elderly populations. A meta-analysis of three studies showed a moderate correlation in subjects with neuromuscular diseases (r= 0.62, 95% CI = 0.52-0.71,p< 0.01). A high risk of bias was identified regarding the justification of the sample size and blinding of the evaluators. SBCT has been presented as an alternative to assess VC in the absence of specific equipment. There is a clear relationship between SBCT and VC, especially in neuromuscular and hospitalized individuals. New validation studies conducted with greater control of potential bias risks are necessary.

Non-traditional biomarkers of eating disorder symptoms among female college students.

Background: Eating disorders (ED) are often diagnosed at an advanced stage because traditional symptoms related to unhealthy eating habits are poorly recognized. ED may be also associated with non-traditional and objective biomarkers, which could prove an important screening tool to support health care professionals in diagnosing, treating, and ultimately preventing ED. Aim: To investigate the association between non-traditional physiological ED biomarkers and symptoms of ED among female college students. Methods: This study included 113 female college students, aged 18 to 23 years, enrolled in their first semester as a Bachelor of Health Sciences undergrad at public universities in the urban zone of Recife, Brazil. Symptoms of ED were measured by self-report questionnaires. Circulating levels of IL-6, IL-10, leptin, insulin, ghrelin, PYY and adiponectin were assessed using commercial immunoassays. Results: Students with symptoms of an ED exhibited higher values of IL-6 (p = 0.03) and leptin (p < 0.001) compared to those without symptoms. A positive correlation was found between leptin levels and bulimia nervosa (r = 0.42; p = 0.00), between leptin levels and binge eating (r = 0.38; p = 0.00), and between IL-6 concentrations and binge eating (r = 0.25; p = 0.04). Multiple linear regression analysis with anorexia nervosa, bulimia nervosa and binge eating as dependent variables showed that IL-6 and leptin best explained ED symptoms, even when adjusted for body mass index (BMI). Conclusions: These findings suggest that peripheral peptides, namely leptin and IL-6, are associated with symptoms of ED in female college students. Future studies are needed to determine if there is a causal relationship between these biomarkers and the onset of ED. Relevance for patients: If future longitudinal studies demonstrate causality between the biomarkers assessed here and ED symptoms, these serum makers could be used as screening tool for inappropriate eating behavior. This may in turn improve the early diagnosis, treatment, and, ultimately, the prognosis of patients with ED.