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15th
World Congress Clinical Nutrition
19th
– 22nd September 2010 El Sokhna Resort - Egypt
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Copyright © 2010.
WCCN2010.COM
All rights reserved |
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Circadian
variation in fatty acids
Fabien De Meester1,
Germaine Cornélissen2,
Claudio Galli3, Patrizia
Risè3, Francis Guillaume2,
Ram B Singh4, Agnieszka
Wilczynska-Kwiatek5, Franz Halberg2.
1Tsim Tsoum Institute and
Columbus Paradigm Institute,
Waterloo, Belgium; 2University
of Minnesota, Minneapolis, MN, USA;
3University of Milan,
Milan, Italy; 4Halberg
Hospital and Research Institute,
Moradabad, India; 5Institupe of
Psychology, Katowice, Poland.
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Aim. We
investigated the extent of
predictable variation in fatty acids
associated with ubiquitous circadian
rhythms. This information may help
in the design of a long-term
intervention study in Poland in
several age groups examining effects
of omega-3 supplementation discussed
at this symposium. Subjects and
Methods. One man (F, 61 years of
age) and one woman (G, 59 years of
age) provided blood samples by
finger pricking around the clock at
approximately 4-hour intervals for
24 hours (6 samples each), before
meals. Blood samples from fingertips
were adsorbed on a collecting kit
(Sigma-Aldrich) and analyzed by gas
chromatography for a direct
evaluation of fatty acids. A total
of 40 variables related to
circulating fatty acids was
assessed. The data were analyzed by
cosinor (1), involving the least
squares fit of cosine curves with
periods of 24 or 12 hours. Estimates
were obtained for the MESOR (M,
Midline Estimating Statistic of
Rhythm, a rhythm-adjusted mean), the
double amplitude (2A, a measure of
the predictable extent of change
within one cycle), and the acrophase
(, a measure of the timing of
overall high values recurring in
each cycle). The data were analyzed
for each subject separately as well
as for pooled data after expressing
them as a percentage of their
respective mean values.
Results. A
circadian rhythm could be
demonstrated with statistical
significance (P<0.05) for 7
variables for F and for 2 variables
for G, the small number of samples
notwithstanding. In only 8 of the 40
variables was the 12-hour component
more prominent than the 24-hour one
for F, whereas for G, the 24-hour
component was the most prominent one
in 23 of the 40 variables. After
expressing the data as a percentage
of their respective means and
pooling the data from F and G for
each variable, a circadian rhythm is
detected in 26 cases (65%). The
24-hour component predominates in 32
of the 40 variables (80%). On the
average, the circadian variation
accounts for a predictable excursion
of 14.3% around the 24-hour mean
value (standard deviation: 11.4%),
and up to 51.9%. A circadian rhythm
is readily apparent for both n-3
HUFA and n-6 HUFA. Statistical
significance was not reached,
however, for their ratio (n-3
status).
Discussion and Conclusion.
The statistical significance of a
circadian rhythm in variables
related to fatty acids is reached in
many more cases than the 5% expected
by chance alone. Synchronized
changes of n-6 and n-3 may account
for the failure to detect a
circadian rhythm in n-3 status. They
may be related to changes of
lipoproteins that contain both of
them in a given ratio. Other
putative reasons are the small
sample size and the fact that G
followed an odd schedule on the day
of study, as documented by a
different circadian pattern on the
day of study versus other days in
the case of her blood pressure which
she automatically monitored around
the clock concomitantly.
1. Cornélissen G, Halberg F.
Chronomedicine. In: Armitage P,
Colton T (Eds.) Encyclopedia of
Biostatistics, 2nd ed. Chichester,
UK: John Wiley & Sons Ltd; 2005. p.
796-812.
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