The ratio of animal protein intake to potassium intake is a predictor of bone resorption in space flight analogues and in ambulatory subjects

摘要: BACKGROUND: Bone loss is a critical concern for space travelers, and dietary countermeasure would be of great benefit. Dietary protein potassium-associated bicarbonate precursors may have opposing effects on the acid-base balance in body therefore bone loss. OBJECTIVE: In 2 studies, we examined ability potassium to predict markers metabolism. DESIGN: first study, 8 pairs male identical twins were assigned 1 groups: bed rest (sedentary, or SED, group) with supine treadmill exercise lower-body negative pressure chamber (EX group). second groups 4 subjects lived closed 60 91 d, data collected two three 5-d sessions. Urinary calcium, N-telopeptide, pyridinium cross-links measured before rest; days 5-6, 12-13, 19-20, 26-27; daily during studies. Data analyzed by Pearson's correlation (P < 0.05). RESULTS: The ratio animal intake was significantly correlated N-telopeptide SED group weeks 3 (r = 0.77 0.80) 91-d study 0.75). positively EX 0.83), week 0.84), 0.72) but not either study. both these relations significant vegetable intake. CONCLUSIONS: affect ambulatory bed-rest subjects. Changing this help prevent Earth flight.