Description
Nutrition is an important aspect of medical practice and is one of the
five areas in which chemical pathologists are expected to be
competent. As part of running a nutritional service assessment of
nutritional status is an important aspect of Clinical Biochemistry. In the
first article Dr Callum Livingstone discusses the various protein markers
available for the assessment of nutritional status of patients. He discusses the
physiology and the factors that may inf luence the plasma concentration of
these proteins. The importance of careful interpretation of the results of
these tests is discussed.
It is now known that energy balance is maintained by a complex
interaction of many factors. These include hypothalamic factors such as
neuropeptide Y, factors secreted by the adipose tissue such as leptin and
factors secreted by the gastrointestinal tract. One such factor secreted by the
gastrointestinal tract is ghrelin. Dr Delaney in the second article discusses
the physiology and pathophysiology of ghrelin, the importance of ghrelin
in the secretion of growth hormone as well the role of ghrelin in
stimulating food intake is well described in this article.
Testosterone measurements are important in the investigation of sub
fertility in both males and females. However, the measurement of total and
free testosterone has been a problem in clinical laboratories for a long time.
This is especially so when the serum testosterone is low as in females or
hypogonadal states in the male. In the third article, which is reproduced
here with permission from the publishers of The Aging Male, describes the
validity of androgen assays. Drs Carruthers, Trinick and Wheeler describe
the factors which may inf luence testosterone concentration both preanalytical
and analytical factors. They also describe the importance of using
correct statistical methods to derive the reference range. The difficulties
with testosterone are further shown in the section more than an abstract. In
this section two articles which appeared in recent issues of Clinica Chimca
Acta and Journal of Clinical Endocrinology and Metabolism are discussed.
In the first article in Clin Chim Acta describes the comparison of some
current immunoassay methods with a tandem mass spectrometry method
for the measurement of testosterone. This article shows all immunoassay
are inaccurate and imprecise. In the article in J Clinical Endocrinology &
Metabolism a Position statement on this topic is discussed.
Measurement of glycated haemoglobin is an important investigation
done by clinical biochemists. There has been an ongoing debate about how
best to standardise the methods. Recently The American Diabetes
Association, European Association for the Study of Diabetes, International
Federation of Clinical Chemistry and Laboratory Medicine, and the
International Diabetes Federation have jointly published a consensus
statement about worldwide standardization of glycated haemoglobin. This
statement was published in Diabetologia and Diabetes Care. This statement
is reproduced in this issue of the journal with permission from the
publishers so that all practicing clinical biochemists will be aware of the
steps being taken to standardize this important test.
Finally, we would like to invite readers to submit interesting case
reports that have a particular educational message. The Bulletin will
become more lively and interesting with more contribution from readers.
