|DAWSON-HUGHES, BESS - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|HARRIS, SUSAN - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|PALERMO, NANCY - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|GILHOOLY, CHERYL - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|SHEA, KYLA - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|FIELDING, ROGHER - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
|CEGLIA, LISA - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY|
Submitted to: Journal of Bone and Mineral Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2015
Publication Date: 11/30/2015
Citation: Dawson-Hughes, B., Harris, S.S., Palermo, N.J., Gilhooly, C.H., Shea, K., Fielding, R.A., Ceglia, L. 2015. Potassium bicarbonate supplementation lowers bone turnover and calcium excretion in older men and women a randomized dose-finding trial. Journal of Bone and Mineral Research. 30(11):2103-2111. doi: 10.1002/jbmr.25.
Interpretive Summary: Cereal grains and protein, once consumed and metabolized, add acid to the body. In contrast, fruits and vegetables add alkali. The diets of many older Americans are acid producing because they contain too few fruits and vegetables to neutralize the amounts of acid load resulting from the grains and protein being consumed. There is evidence that acid producing diets may promote bone loss in older adults. This study was done to determine the extent to which different doses of alkali would reduce short-term indicators of bone loss in healthy older adults. In the 244 participants, we found that, when compared with placebo and with higher doses of alkali, a moderate dose of alkali in the form of potassium bicarbonate pills had the most favorable effect on the main biomarker of bone loss. A large, long-term trial is needed to assess the effect of this amount of alkali on rates of bone loss.
Technical Abstract: The acid load accompanying modern diets may have adverse effects on bone and muscle metabolism. Treatment with alkaline salts of potassium can neutralize the acid load, but the optimal amount of alkali is not established. Our objective was to determine the effectiveness of two doses of potassium bicarbonate (KHCO3)compared with placebo on biochemical markers of bone turnover, and calcium and nitrogen (N) excretion. In this double-blind, randomized, placebo-controlled study, 244 men and women age 50 years and older were randomized to placebo or 1mmol/kg or 1.5mmol/kg of KHCO3 daily for 3 months; 233 completed the study. The primary outcomes were changes in 24-hour urinary N-telopeptide (NTX) and N; changes in these measures were compared across the treatment groups. Exploratory outcomes included 24-hour urinary calcium excretion, serum amino-terminal propeptide of type I procollagen (P1NP), and muscle strength and function assessments. The median administered doses in the low-dose and high-dose groups were 81 mmol/day and 122 mmol/day, respectively. When compared with placebo, urinary NTX declined significantly in the low-dose group (p=0.012, after adjustment for baseline NTX, gender, and change in urine creatinine) and serum P1NP declined significantly in the low-dose group (p=0.004, adjusted for baseline P1NP and gender). Urinary calcium declined significantly in both KHCO3 groups versus placebo (p < 0.001, adjusted for baseline urinary calcium, gender, and changes in urine creatinine and calcium intake). There was no significant effect of either dose of KHCO3 on urinary N excretion or on the physical strength and function measures. KHCO3 has favorable effects on bone turnover and calcium excretion and the lower dose appears to be the more effective dose. Long-term trials to assess the effect of alkali on bone mass and fracture risk are needed.