Collagen protein supplementation does not modulate biomarkers of bone metabolism following total hip arthroplasty: a randomized, double-blind, placebo-controlled trial.

BACKGROUND & AIMS: Healing after total hip arthroplasty (THA) involves remodelling of collagenous tissues, such as bone. While collagen protein supplementation has been suggested to modulate bone metabolism, the effects following THA are yet to be investigated. Therefore, we aimed to characterize changes in biomarkers of bone metabolism following THA and to assess the potential modulating effects of collagen protein supplementation.

METHODS

In this randomized, double-blinded, placebo-controlled trial, 39 older adults (71 ± 6 y; 27.4 ± 3.6 kg/m2) consumed either hydrolysed collagen protein (15 g protein; HC group) or an energy-matched placebo supplement (maltodextrin; 15 g carbohydrates; PLA group) for 14 days following THA. Procollagen type 1 N-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX-1) concentrations were assessed in blood samples obtained before surgery (pre-surgery), immediately following surgery (t = 0), and one (t = 1), four (t = 4), and fifteen (t = 15) days post-surgery. Patient-reported outcome measures (PROMs) were assessed at pre-surgery, t = 4, and t = 15. Data are shown as mean ± SD and were analysed using 2-way repeated measures ANOVA.

RESULTS

P1NP concentrations decreased from pre-surgery (HC: 53 ± 18, PLA: 58 ± 21 ng/mL) to t = 1 (HC: 21 ± 11, PLA: 25 ± 10 ng/mL), subsequently peaking at t = 15 (HC: 160 ± 44, PLA: 154 ± 55 ng/mL), with no group differences (P-time < 0.001, P-interaction = 0.588). CTX-1 showed a steady increase from pre-surgery (HC: 0.50 ± 0.16, PLA: 0.50 ± 0.23 ng/mL) throughout the follow-up period, also peaking at t = 15 (HC: 0.66 ± 0.19, PLA: 0.71 ± 0.25 ng/mL) with no group differences (P-time < 0.001, P-interaction = 0.168). While most PROMs improved over time similarly in both groups, pain at rest declined significantly in the HC group only (HC: 6 ± 3 to 2 ± 2, P < 0.001; PLA: 4 ± 3 to 3 ± 2, P = 0.054; P-interaction = 0.007).

CONCLUSION

Bone turnover markers greatly increase following total hip arthroplasty, but this is not modulated by daily collagen supplementation.

CLINICAL TRIAL REGISTRY: This trial was registered on 20 July 2021 at the Dutch Trial Register (NL9608) and is available at https://onderzoekmetmensen.nl/nl/trial/27884.