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Related Concept Videos

Variability: Analysis01:11

Variability: Analysis

Measures of variability are statistical metrics that reveal the dispersion pattern within a dataset. They are pivotal in biostatistics, providing insights into the heterogeneity within health and biological data. Variability signifies the degree to which data points diverge from one another, helping researchers understand the potential range of values and associated uncertainty within the data.
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Pharmacokinetics is a vital branch of pharmacology that examines how drugs are absorbed, distributed, metabolized, and excreted by the body. Two key methodologies in pharmacokinetics are plasma drug concentration studies and urinary drug excretion analyses, both of which provide critical insights into a drug's therapeutic efficacy and bioavailability.Plasma Drug Concentration-Time StudiesPlasma drug concentration-time studies involve analyzing blood samples at specific intervals to quantify...
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Dosage Regimen: Individualization01:24

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Blood Studies for Cardiovascular System II: CRP, Hcy, and Cardiac Natriuretic Peptide Markers

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Biological variability and reference intervals for total plasma homocysteine.

E Rossi1, J P Beilby, B M McQuillan

  • 1Biochemistry Section, Pathcentre, QE II Medical Centre, Nedlands, Australia. Ric.Rossi@health.wa.gov.au

Annals of Clinical Biochemistry
|June 17, 1999
PubMed
Summary

Plasma homocysteine levels show low individual variation, suggesting one measurement suffices. Higher serum folate is linked to significantly lower homocysteine, supporting folate-replete reference ranges.

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Area of Science:

  • Biochemistry
  • Clinical Chemistry
  • Nutritional Science

Background:

  • Plasma homocysteine is a risk factor for various health conditions.
  • Understanding homocysteine variability and its relationship with folate is crucial for accurate clinical assessment.

Purpose of the Study:

  • To determine the intra-individual biological variability of plasma homocysteine.
  • To investigate the association between plasma homocysteine and serum folate levels in a large adult population.
  • To propose an improved reference range for homocysteine based on folate status.

Main Methods:

  • Intra-individual variability assessed in 20 healthy subjects.
  • Population study involved 1109 randomly selected fasting adults.
  • Plasma homocysteine and serum folate levels were measured.
  • Age- and gender-specific reference intervals were calculated.

Main Results:

  • Low intra-individual coefficient of variation (8.3%) for plasma homocysteine.
  • Significant inverse correlation between serum folate quartiles and mean plasma homocysteine (P = 0.0001).
  • Subjects with the highest folate levels had the lowest homocysteine concentrations.

Conclusions:

  • A single plasma homocysteine measurement is reliable for assessing an individual's average concentration.
  • Folate repletion significantly impacts homocysteine levels.
  • An 'ideal' homocysteine reference range should consider folate status for improved clinical relevance.