Dietary
Conjugated Linoleic Acid (CLA) as a Potential Treatment for Metabolic
Bone Disease
Hope Weiler(1,2), Susan Austin(1),
Shirley Fitzpatrick-Wong(1), Evan Nitschmann(2),
Neda Bankovic-Calic(2), Rebecca Mollard(1),
Harold Aukema(1,2), Malcolm Ogborn(1,2)
Departments of Human Nutritional Sciences(1), and Pediatrics
and Child Health(2), University of Manitoba, Winnipeg, Manitoba.
Metabolic
bone disease is characterized by elevations in parathyroid hormone (PTH)
along with elevated rates of bone turnover. This is a feature of chronic
renal disease. Since release of PTH is dependent on prostaglandin E2 (PGE2)
synthesis and CLA is known to reduce synthesis of PGE2, this study was
conducted to examine if feeding conjugated linoleic acid (CLA) would suppress
hyperparathyroidism and high turnover bone disease secondary to polycystic
kidney disease (PKD). Fifty-two weanling male Han:SPRD-cy rats were randomized
to identical diets supplemented with and without CLA (1% of dietary fat)
for 8 weeks. Main outcome measurements were: kidney weight, urea nitrogen
and creatinine clearance; parathyroid hormone (PTH), bone formation and
resorption; and femur bone mass using dual energy x-ray absorptiometry.
Serum PTH and bone turnover were elevated in PKD affected rats. CLA feeding
resulted in attenuation of PTH levels in both affected and non-affected
rats (by 60%), but did not alter bone formation and resorption. Bone mass
was not affected by CLA. Reduction in PTH may open possibilities for CLA
as an adjunctive therapy in secondary hyperparathyroidism.
This research was supported by grants from Dairy Farmers of Canada, The
Childrenís Hospital Foundation of Manitoba Inc. and NSERC.
