Pharmacokinetics of β-alanine using different dosing strategies

Introduction: The ergogenic response following long-term ingestion of beta-alanine shows a high inter-individual variation. It is hypothesized that this variation is partially caused by a variable pharmacokinetic response induced by inferior dosing strategies. At this point most supplements are either taken in a fixed amount (x g), as is the case with beta-alanine, or relative to body weight (x g per kg BW), but there is currently neither consensus nor a scientific rationale on why these or other dosing strategies should be used. The aim of this study is to objectify and understand the variation in plasma pharmacokinetics of a single oral b-alanine dose supplemented as either a fixed or a weight-relative dose (WRD) in an anthropometric diverse sample. Methods: An anthropometric diverse sample ingested a fixed dose (1,400mg) (n = 28) and a WRD of beta-alanine (10 mg/kg BW) (n = 34) on separate occasions. Blood samples were taken before and at nine time points (up to 4 h) after beta-alanine ingestion in order to establish a pharmacokinetic profile. Incremental area under the curve (iAUC) was calculated by the trapezoidal rule. Plasma beta-alanine was quantified using HPLC-fluorescence. Results: The variation coefficient (CV%) of the iAUC was 35.0% following ingestion of 1,400mg b-alanine. Body weight explained 30.1% of the variance and was negatively correlated to iAUC (r = -0.549; p = 0.003). Interestingly, the CV% did not decrease with WRD (33.2%) and body weight was positively correlated to iAUC in response to the WRD (r = 0.488; p = 0.003). Conclusion: Both dosing strategies evoked an equally high inter-individual variability in pharmacokinetic plasma profile. Strikingly, while body weight explained a relevant part of the variation observed following a fixed dose, correction for body weight did not improve the homogeneity in b-alanine plasma response. We suggest to put more effort into the optimization of easy applicable and scientifically justified personalized dosing strategies

Results of Conserve Plus Hip Resurfacing: prospective clinical, radiographic and ion study.

We report the 3- to 5-year clinical, radiographic and serum ion level results of a prospective consecutive cohort of 42 hip resurfacing arthroplasties using the Conserve Plus implant in 39 male patients that were operated on by a single surgeon in a community hospital. Average age was 53 years (range 34-67) at surgery.  There was one revision for a subcapital neck fracture. There were no surgery related complications. The survival of the implant was 95%.  Clinical evaluation showed excellent results with a modified Charnley score of 17.6/18, Harris Hip Score of 96.2/100, WOMAC  of 95.1/100, Oxford Score 15.3, and UCLA-Activity Score of 8/10. Radiographic analysis showed no implant at risk, no migration or signs of loosening, no neck narrowing and no osteolysis at final follow-up. Average cup inclination angle was 43.5° with 2 outliers (34° and 57°).  Ion level study showed average cobalt in serum 1.04 µg/l (range 0-4) for the whole group, 0.7 µg/l (range 0 -3) in patients with unilateral resurfacing and 2.0 µg/l (range 0 – 4) in patients with bilateral resurfacing.  All patients had ion levels within the safe zone