Proposition of decision limits for serum lipids in Brazilian children aged one to 13 years / Proposição de limites de decisão dos lipídeos séricos para crianças brasileiras de um a 13 anos de idade

Abstract Objective: To determine decision limits for total cholesterol, LDL-cholesterol, non-HDL cholesterol, HDL-cholesterol, and triglycerides in healthy children and adolescents from Cuiabá, Brazil. Methods: This was a cross-sectional study of 1866 healthy children and adolescents randomly selected from daycare centers and public schools in Cuiabá. The desirable levels of serum lipids were defined using the classic criteria, i.e., total cholesterol, LDL-cholesterol, non-HDL cholesterol, and triglycerides levels below the P75 percentile, and HDL-c above the P10 percentile. Results: For CT, P75 was: 160 mg/dL for the age range of 1 to <3 years, 170 mg/dL for ≥3 to <9 years, and 176 mg/dL for ≥9 to <13 years. For non-HDL cholesterol, it was 122 mg/dL for the age range of 1 to <13 years. For LDL-c, it was 104 mg/dL at the age range of 1 to <9 years and 106 mg/dL from ≥9 to <13 years. For TG, it was 127 mg/dL from 1 to <2 years; 98 mg/dL from ≥2 to <6 years; and 92 mg/dL from ≥6 to <13 years. As for HDL-cholesterol, P10 was 24 mg/dL, 28 mg/dL, 32 mg/dL, and 36 mg/dL, for the age ranges of 1 to <2 years, ≥2 to <3 years, ≥3 to <4 years, and ≥4 to <13 years, respectively. Conclusion: The decision limits for the serum lipid levels defined in this study differed from those observed in the current Brazilian and North-American guidelines, especially because it differentiates between the age ranges. Using these decision limits in clinical practice will certainly contribute to improve the diagnostic accuracy for dyslipidemia in this population group.

Resumo Objetivo: Determinar limites de decisão (LD) para o colesterol total (CT), LDL-colesterol (LDL-c), colesterol não-HDL (c-NHDL), HDL-colesterol (HDL-c) e triglicérides (TG) em crianças e adolescentes saudáveis de Cuiabá. Método: Estudo transversal envolvendo 1.866 crianças e adolescentes saudáveis de creches e escolas municipais públicas de Cuiabá, aleatoriamente selecionadas. Os LD desejáveis dos lipídeos séricos foram definidos pelos critérios clássicos, isto é, níveis de CT, LDL-c, c-NHDL, TG abaixo do percentil 75, e de HDL-c acima do percentil 10. Resultados: Os P75 para CT foram: 160 mg/dL para a faixa etária de 1 a < 3 anos, 170 mg/dL para ≥ 3 a < 9 anos e 176 mg/dL para ≥ 9 a < 13 anos. Para o c-NHDL, de 122 mg/dL na faixa etária de 1 a < 13 anos. LDL-c: 104 mg/dL na faixa etária de 1 a < 9 anos e 106 mg/dL de ≥ 9 a < 13 anos. TG: 127 mg/dL entre 1 a < 2 anos; 98 mg/dL de ≥ 2 a < 6 anos; e 92 mg/dL de ≥ 6 a < 13 anos. Quanto ao HDL-c, o P10, foi de 24 mg/dL, 28 mg/dL, 32 mg/dL e 36 mg/dL, para as faixas etárias de 1 a < 2 anos, ≥ 2 a < 3 anos, ≥ 3 a < 4 anos e ≥ 4 a < 13 anos, respectivamente. Conclusão: Os LD dos níveis séricos de lipídeos definidos neste estudo diferem daqueles apresentados nas diretrizes brasileiras e americanas atuais, especialmente por fazer a diferenciação entre as idades. Utilizar tais LD em nossa prática clínica certamente contribuirá para melhorar a acurácia do diagnóstico de dislipidemia nesse grupo populacional.

Quality Requirements for Reference Intervals and Decision Limits in Clinical Laboratory / 现代检验医学杂志

Reference intervals and decision limits are critical parts of the clinical laboratory report.The evaluation ot their correct use represents a tool to verify the post analytical quality.Four elements are identified as indicators:① The use of decision limits for lipids and glycated hemoglobin.② The use of common reference values.③The presence of gender-related reference intervals for at least the following common serum measurands (besides obviously the fertility relate hormones):alkaline phosphatase (ALP),alanine aminotransferase (ALT),creatine kinase (CK),creatinine,gamma-glutamyl transferase (GGT),IgM,ferritin,iron,transferrin,urate,red blood cells (RBC),hemoglobin (Hb) and hematocrit (HCT).④) The presence of age-related reference intervals.The problem of specific reference intervals for elderly people is discussed,but their use is not recommended.On the contrary it is necessary the presence of pediatric age-related reference intervals at least for the following common serum measurands:ALP,amylase,creatinine,inorganic phosphate,lactate dehydrogenase,aspartate aminotransferase,urate,insulin like growth factor 1,white blood cells,RBC,Hb,HCT,alfafetoprotein and fertility related hormones.The lack of such reference intervals may imply significant risks for the patients.

Investigation and Analysis of Reference Intervals and Decision Limits of Reticulocyte Count in China / 现代检验医学杂志

Objective To investigate and analyze the current situation of reference intervals and decision limits of reticulocyte count in China.Methods The information related to upper/lower limits,decision limits,data resources,method principles, instruments and reagents of reticulocyte count in 2014 was collected via the external quality assessment software system based on website.The participants were divided according to their methods and instruments.The SPSS 1 9.0 was used for conducting the data analysis and statistics of results for each group.Results There were 276 laboratories submitting the val-id results.The major resources for reference intervals came from national guide to clinical laboratory procedures (53.99%), instructions of instrument manufacturers (16.30%),textbook (9.78%),instructions of reagents manufacturers (9.06%) and others.The major resources for decision limits were national guide to clinical laboratory procedures (56.06%),instruc-tions of instrument manufacturers (16.67%),textbook (7.58),instructions of reagents manufacturers (7.58%)and others. The medians and averages of upper/lower limits and decision limits among subgroups were close,whereas the P2.5 and P97.5 were significant discrepancies.Only 45.65% and 48.48% of participant laboratories had verified reference intervals and deci-sion limits before clinic use.The lower limits and decision limits among subgroups had nostatistical difference (P>0.05), where as the upper limits of different instrument groups had significant differences (P<0.001).Conclusion The current situation of reference intervals and decision limits of reticulocyte count is unsatisfactory.It is certain to establish a uniformed reference interval and decision limits for reticulocyte count,which provides a reference for the standardization of reticulocyte count testing.