The applicant's research group has provided data which suggests that dietary protein is a potent regulator of calcium metabolism in young healthy women, an age group in whom the interaction of dietary protein and calcium metabolism has not been extensively studied. The PI reports that in this age group, within 4 days of the introduction of a high protein diet, hypercalciuria develops as a consequence, in part, of hyperparathyroidism with marked elevations in serum parathyroid hormone and 1,25(OH)2 vitamin D. Significantly, N-telopeptide, a marker of bone resorption, paralleled dietary protein intake such that this marker for bone resorption was lowest on the low protein diet, and highest when dietary protein was high. The above data supports the concept that dietary protein influences bone turnover in young women. The applicant now intends to study these relationships in postmenopausa women who are at a highest risk for osteoporosis. The goal of the proposed research is to quantify the effect of manipulating dietary protein on calcium kinetics and bone metabolism in young and older women. The PI will employ stable isotopic techniques in order to measure the effects of protein on calcium flux across the intestine and on bone accretion and resorption. Twelve healthy adult women (6 young and 6 older) will consume well-balanced, ten-day, experimental diets containing low, medium, and high levels of protein while calcium kinetics and bone turnover are assessed. The above experiments should help to clarify the effects of dietary protein on calcium absorption and bone turnover and allow for a more precise determination of the levels of protein intake which are necessary to optimize skeletal health in women.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK052128-02
Application #
2905952
Study Section
Nutrition Study Section (NTN)
Program Officer
Margolis, Ronald N
Project Start
1998-06-15
Project End
2001-05-31
Budget Start
1999-06-01
Budget End
2000-05-31
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Yale University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Surdykowski, Anna K; Kenny, Anne M; Insogna, Karl L et al. (2010) Optimizing bone health in older adults: the importance of dietary protein. Aging health 6:345-357
Kerstetter, Jane E; Wall, Diane E; O'Brien, Kimberly O et al. (2006) Meat and soy protein affect calcium homeostasis in healthy women. J Nutr 136:1890-5
Kerstetter, Jane E; O'Brien, Kimberly O; Caseria, Donna M et al. (2005) The impact of dietary protein on calcium absorption and kinetic measures of bone turnover in women. J Clin Endocrinol Metab 90:26-31
Kerstetter, Jane E; O'Brien, Kimberly O; Insogna, Karl L (2003) Low protein intake: the impact on calcium and bone homeostasis in humans. J Nutr 133:855S-861S
Kerstetter, J E; Mitnick, M E; Gundberg, C M et al. (1999) Changes in bone turnover in young women consuming different levels of dietary protein. J Clin Endocrinol Metab 84:1052-5