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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Healthy Body Weight Research » Research » Publications at this Location » Publication #134478
Title: INADEQUATE COPPER (CU) INTAKE REDUCES SERUM INSULIN-LIKE GROWTH FACTOR-1 (IGF-1) AND BONE STRENGTH IN GROWING RATS

Author
item ROUGHEAD, ZAMZAM - GFHNRC
item Lukaski, Henry

Submitted to: Journal of Bone and Mineral Research
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2002
Publication Date: 2/1/2003
Citation: Roughead, Z.K., Lukaski, H.C. 2002. Inadequate copper (Cu) intake reduces serum insulin-like growth factor-1 (IFG-1) and bone strength in growing rats [abstract]. 24th Annual Meeting of the American Society for Bone and Mineral Research. September 20-24, 2002. San Antonio, TX.

Interpretive Summary:

Technical Abstract: This study was designed to determine whether the interaction between graded intakes of zinc (Zn) and copper (Cu) affected serum IGF-1 concentration and bone quality in growing rats. In a 3x3 factorial design, weanling male rats (n = 84) were randomly assigned to 12 groups and were fed one of 9 modified AIN-93G basal diets with varying amounts of Cu (0.3, 3, and 10 mg/kg, designated as LC, MC, and HC, respectively) and Zn (5, 15, 45 mg/kg, designated as LZ, MZ, and HZ, respectively) for 6 weeks. A group of rats were pair-fed to each LZ group. Body weights were primarily determined by dietary Zn and were the highest in the HZ groups (p=0.02). Although dietary Zn had a tendency to influence serum IGF-1 concentration (p=0.09), dietary Cu was the main determinant of this variable (p<0.0001). Lumbar vertebral density (L4),was influenced by dietary Zn, Cu, and interaction of these two minerals (p<0.05). Variabilities in femur density and breaking strength were mainly determined by dietary Cu (p<0.05). Compared to the HC groups, serum IGF-1, vertebral and femur densities and femur breaking strength were the lowest in the LC groups (by 27%, 2%, 3% and 14%, respectively, p<0.05). Also, calcium to nitrogen ratio was the lowest in the LC groups (p=0.05). Serum osteocalcin was significantly affected by Cu and Cu x Zn interaction (p<0.01) and was the lowest in the HCHZ group. Low Cu intake caused a dramatic decline in serum IGF-1. Also, compared to dietary Zn, dietary Cu had a stronger influence on bone quality. The poor quality of spinal and long bones associated with inadequate Cu intake may be explained, in part, by the decreased serum IGF-1 and alterations in the composition of the organic and inorganic matrix of these bones.