Sodium assessment in neonates, infants, and children: a systematic review.

Hyponatremia is a common disorder in childhood. The indirect and the direct potentiometry are currently the most popular techniques employed for sodium assessment, although discrepancies between the two techniques may be > 10 mmol/L. It is known that < 20% of the recently published articles report information about the technique used for sodium analysis, but no data are available on pediatric studies. This study aimed at investigating the laboratory technique employed for sodium measurement in studies conducted in childhood. A systematic literature search in PubMed, Embase, and Web of Science was undertaken to identify articles containing the word "hyponatremia" in the title between 2013 and 2020. Papers with < 10 subjects were excluded. A total of 565 articles were included. Information on the laboratory technique used for sodium analysis was more commonly (p = 0.035) reported in pediatric (n = 15, 28%) than in non-pediatric (n = 81, 16%) reports. The frequency of reports with and without information on the technique for sodium assessment was not different with respect to the study characteristics, the quartile of the journal where the paper was published, the country income setting, and the inclusion of neonates among the 54 pediatric studies.   Conclusion: Most pediatric papers do not report any information on the technique used for sodium analysis. Although international authorities have recommended the implementation of direct potentiometry, a low awareness on this issue is still widespread in pediatric research. What is Known: • Direct potentiometry and indirect potentiometry are currently employed for sodium analysis in blood. • Direct potentiometry is more accurate. What is New: • Less than 30% of pediatric articles provide information on the technique employed for sodium analysis in blood. • Indirect potentiometry is more frequently employed than direct potentiometry in pediatric studies.

What about TSH and Anti-Thyroid Antibodies in Patients with Autoimmune Thyroiditis and Celiac Disease Using a Gluten-Free Diet? A Systematic Review.

The prevalence of celiac disease (CD) in patients with chronic autoimmune thyroiditis (CAIT) is estimated to be between 2 and 7.8%. A gluten-free diet (GFD) in patients with CD is suggested to have a beneficial effect on CAIT. Thus, the present systematic review was undertaken to achieve more robust evidence about the change in thyroid stimulating hormone (TSH) and thyroid-specific antibodies (T-Ab) levels obtained in CD patients following a GFD. A specific search strategy was planned. The last search was performed on March 2022. The following data were mainly searched for in order to be extracted: sample size, mean and/or median with standard deviation (SD), and error (SE), individually, of thyroid hormones and T-Ab at baseline and after GFD, and the duration of the study. The initial search retrieved 297 records and 6 articles met the inclusion criteria. In total, 50 patients with both CD and CAIT and 45 controls were reported. The effects of a GFD on the thyroid hormonal and immunological profile could be extracted only in a part of the studies. Two studies were case reports. A low risk of bias was observed. These findings advise further studies, ideally randomized, in order to better investigate the potential relationship between GFD and thyroid homeostasis. The level of evidence is not still sufficient to recommend GFD to patients with CAIT.

Which laboratory technique is used for the blood sodium analysis in clinical research? A systematic review.

BACKGROUND: Circulating sodium is analyzed by flame spectrometry and indirect or direct potentiometry. The differences between estimates returned by the three techniques are often relevant. It is unknown whether peer-reviewed international publications focusing on this parameter provide information about the technique. Objectives of the study were to ascertain if information about the employed technique is provided. CONTENT: A search in the National Library of Medicine for articles whose title contains "hyponatr[a]emia" was performed. We restricted the search to clinical reports including 10 or more humans published in the 2013-2015 and 2017-2019 periods. Authors of papers not reporting the technique were contacted to obtain this information. The study design and journal quartile ranking of each article were also evaluated. SUMMARY: For the final analysis, we included 361 articles (2013-2015, n=169; 2017-2019, n=192). Information about the laboratory technique was given in 61(17%) articles. Thanks to our inquiry, we collected this information for 116(32%) further reports. Indirect potentiometry was the most frequently used technique, followed by direct potentiometry. Spectrometry was used in a small minority of studies. Study design, journal ranking and study period did not modulate the mentioned frequency. OUTLOOK: Most articles focusing on hyponatremia do not provide information on the laboratory technique. This parameter is nowadays analyzed by indirect or, less frequently, direct potentiometry. The figures are similar for high and low impact factor journals and for the 2013-2015 and the 2017-2019 periods. Many authors, reviewers and editors likely assume that the results of this parameter are not influenced by the technique.