Diabetes, Vol 48, Issue 1 112-116, Copyright © 1999 by American Diabetes Association
Relationships between maternal risk of insulin resistance and the child's muscle membrane fatty acid composition
LA Baur, J O'Connor, DA Pan and LH Storlien
Department of Paediatrics and Child Health, University of Sydney, Australia. lbaur@usyd.edu.au
In adult humans, insulin resistance is associated with relatively low
proportions of polyunsaturated fatty acids (PUFAs) in muscle membrane
structural lipid. The aim of the present study was to determine the
relationship between young children's muscle membrane fatty acid (FA)
composition and indices of insulin resistance in their mothers. Muscle
biopsy specimens obtained at the time of elective surgery from 83 children
(54 boys), aged 0.78 +/- 0.05 year (mean +/- SE), were analyzed for
phospholipid FA composition. Fasting blood samples were collected from the
mothers of the children, and maternal BMIs were calculated. Stepwise
multiple regression analysis showed that after accounting for the effect of
breast-feeding, log maternal insulin levels were inversely associated with
the child's muscle membrane docosahexaenoic acid (22:6 n-3; R2 = 0.29, P =
0.0006) and the sum of the n-3 PUFAs (R2 = 0.23, P = 0.0016) but positively
associated with the sum of the n-6 PUFAs (R2 = 0.05, P = 0.03) and the
n-6/n-3 PUFA ratio (R2 = 0.20, P = 0.007). Independent of breast-feeding,
log maternal triglyceride levels were inversely associated with the child's
muscle membrane unsaturation index (a measure of unsaturation) (R2 = 0.08,
P = 0.005). Maternal BMI; total, LDL, and HDL cholesterol; and the child's
age, sex, and birth weight were not significant predictors of the child's
muscle membrane FA composition. Thus, maternal fasting insulin and
triglyceride levels are significant predictors of the FA composition of the
child's muscle membrane. The less unsaturated muscle membranes in children
whose mothers have higher fasting insulin and triglyceride levels may
reflect a genetic reluctance to incorporate PUFAs into membranes, thus
predisposing them to insulin resistance syndromes.