M Kyla Shea1, Bess Dawson-Hughes1. 1. Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts.
Abstract
Context: Elevated urine net acid excretion (NAE), indicative of subclinical metabolic acidosis, has been associated with higher bone turnover. Urine citrate, which is a common clinical measure, changes in response to acid-base status but its association with bone turnover is uncertain. Objective: We evaluated the association between change in urine citrate and change in bone turnover and calcium excretion. Design, Intervention, and Participants: A total of 233 healthy men and women ≥60 years old were randomly assigned to 1.0 mmol/kg/d potassium bicarbonate (KHCO3), 1.5 mmol/kg/d KHCO3, or placebo for 84 days. Outcome Measures: Urine citrate, NAE, N-telopeptide of collagen type-I (NTX), calcium excretion, and serum amino-terminal propeptide of type 1 procollagen (P1NP) were measured before and after intervention. Results:Urine citrate increased dose dependently after KHCO3 supplementation (P trend < 0.001). The urine citrate change was significantly inversely associated with P1NP change (P = 0.021) but not with change in NTX (P = 0.051) or calcium excretion (P = 0.652). The NAE change was positively associated with change in NTX and calcium excretion (P ≤ 0.003) but not with change in P1NP (P = 0.051). When the urine citrate change and NAE change were included in the same model, the urine citrate change was not associated with change in NTX, calcium excretion, or serum P1NP (P ≥ 0.086), whereas change in NAE remained associated with change in NTX and calcium excretion (P ≤ 0.003). Conclusion:Urine citrate may not be a suitable alternative to NAE when assessing acid-base status in relation to bone turnover in older adults.
RCT Entities:
Context: Elevated urine net acid excretion (NAE), indicative of subclinical metabolic acidosis, has been associated with higher bone turnover. Urine citrate, which is a common clinical measure, changes in response to acid-base status but its association with bone turnover is uncertain. Objective: We evaluated the association between change in urine citrate and change in bone turnover and calcium excretion. Design, Intervention, and Participants: A total of 233 healthy men and women ≥60 years old were randomly assigned to 1.0 mmol/kg/d potassium bicarbonate (KHCO3), 1.5 mmol/kg/d KHCO3, or placebo for 84 days. Outcome Measures: Urine citrate, NAE, N-telopeptide of collagen type-I (NTX), calcium excretion, and serum amino-terminal propeptide of type 1 procollagen (P1NP) were measured before and after intervention. Results: Urine citrate increased dose dependently after KHCO3 supplementation (P trend < 0.001). The urine citrate change was significantly inversely associated with P1NP change (P = 0.021) but not with change in NTX (P = 0.051) or calcium excretion (P = 0.652). The NAE change was positively associated with change in NTX and calcium excretion (P ≤ 0.003) but not with change in P1NP (P = 0.051). When the urine citrate change and NAE change were included in the same model, the urine citrate change was not associated with change in NTX, calcium excretion, or serum P1NP (P ≥ 0.086), whereas change in NAE remained associated with change in NTX and calcium excretion (P ≤ 0.003). Conclusion: Urine citrate may not be a suitable alternative to NAE when assessing acid-base status in relation to bone turnover in older adults.
Authors: Bess Dawson-Hughes; Susan S Harris; Nancy J Palermo; Cheryl H Gilhooly; M Kyla Shea; Roger A Fielding; Lisa Ceglia Journal: J Bone Miner Res Date: 2015-07-28 Impact factor: 6.741
Authors: L S Tabatabai; S R Cummings; F A Tylavsky; D C Bauer; J A Cauley; S B Kritchevsky; A Newman; E M Simonsick; T B Harris; A Sebastian; D E Sellmeyer Journal: J Clin Endocrinol Metab Date: 2015-02-02 Impact factor: 5.958
Authors: Audry H Garcia; Oscar H Franco; Trudy Voortman; Ester A L de Jonge; Noelia G Gordillo; Vincent W V Jaddoe; Fernando Rivadeneira; Edith H van den Hooven Journal: Am J Clin Nutr Date: 2015-11-04 Impact factor: 7.045