Address for correspondence: M. Kune
ová, M.D., Ph.D., Obesity Management Center, Third Department of Medicine, First Medical School, Charles University, U nemocnice 2, 128 08 Prague 2, Czech Republic. Voice: +420 2 24962921; fax: +420 2 24919780.
mkune{at}lf1.cuni.cz Ann. N.Y. Acad. Sci. 967: 311-323 (2002).
We have reported strong intrapair resemblances (IPRs) in serum
phosphatidylcholine (PC) fatty acid composition within adult
monozygotic twins living apart. This study assessed the contribution
of genetic factors to changes in serum and adipose tissue fatty
acids resulting from weight loss and followed by a subsequent
year of weight maintenance. Eleven pairs of female obese monozygotic
twins (age: 38.9 ± 1.8; BMI: 32.5 ± 0.9) were
recruited for the study. Fasting serum and adipose tissue were
obtained after 1 week of inpatient stabilization, after 1 month
of inpatient very-low-calorie diet (VLCD), and again after 1
year of outpatient weight maintenance. Fatty acids in serum
lipid fractions and adipose tissue were quantitated by gas chromatography.
Using multiple regression adjusted for age and initial value,
IPRs were determined for the changes induced by VLCD and by
the year of weight maintenance. There were few IPRs in nonessential
fatty acids. By contrast, there were numerous IPRs for essential
fatty acids (EFA), especially in the n-3 family across the VLCD.
Following the maintenance year, however, frequent IPRs for nonessential
fatty acids were seen, particularly in serum PC, and strong
IPRs were seen for 18:3 n-3 and 20:5 n-3 across multiple fractions.
These results infer the existence of strong genetic factors
determining both the nonessential and EFA compositions of tissue
lipids in humans independent of diet. Of particular note were
the consistent IPRs for n-3 fatty acids despite dietary stress,
indicating that the conservation and distribution of this EFA
family are subject to considerable genetic variance in humans.
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