Pilot Study Examining the Influence of Potassium Bicarbonate Supplementation on Nitrogen Balance and Whole-Body Ammonia and Urea Turnover Following Short-Term Energy Restriction in Older Men.

摘要: With aging there is a chronic low-grade metabolic-acidosis that may exacerbate negative protein balance during weight loss. The objective of this randomized pilot study was to assess the impact 90 mmol∙day−1 potassium bicarbonate (KHCO3) versus placebo (PLA) on 24-h urinary net acid excretion (NAE), nitrogen (NBAL), and whole-body ammonia urea turnover following short-term diet-induced Sixteen (KHCO3; n = 8, PLA; 8) older (64 ± 4 years) overweight (BMI: 28.5 2.1 kg∙day−1) men completed 35-day controlled feeding study, with 7-day weight-maintenance phase followed by 28-day 30% energy-restriction phase. KHCO3 or PLA supplementation began energy restriction. NAE, NBAL, (15N-glycine) were measured at end phases. Following restriction, NAE −9.8 27.8 in 43.9 (p < 0.05). No significant group time differences observed NBAL turnover. Ammonia synthesis breakdown tended 0.09) be higher vs. inversely associated (r −0.522; p 0.05) all subjects. This suggests some benefit exist restriction as lower indicated synthesis.