Effects of β-carotene intake on the risk of fracture: A Bayesian meta-analysis

Abstract

Introduction The association between β-carotene intake and risk of fracture has been reported inconsistently. We conducted a meta-analysis to investigate the association between β-carotene intake and risk of fracture using a Bayesian approach. Methods We systematically searched PubMed, EMBASE and Cochrane library database for relevant articles until December 2019. We also performed a hand search based on reference lists from published articles. The Bayesian random effect model was used to synthesize data from individual studies. Results Nine studies with a total of 190,545 men and women were included in this meta-analysis. The participants' average age was 59.8 years old. For β-carotene intake, the pooled RR of any fracture was 0.67 (95% Credible Interval (CrI): 0.51-0.82; heterogeneity: P = 0.66, I 2 =0.00%) and 0.63 (95%CrI: 0.44-0. 82) for hip fracture. By study design, the pooled RRs were 0.55 (95% CrI: 0.14-0.96) for case-control studies and 0.82 (95% CrI: 0.58-0.99) for cohort studies. By geographic region, the pooled RRs were 0.58 (95% CrI: 0.28-0.89) for studies conducted in China, 0.86 (95% CrI: 0.35-0.1.37) in America and 0.91(95% CrI: 0.75-1.00) Europe. By gender: the pooled RRs were 0.88 (95% CrI: 0.73-0.99) for males and 0.76 (95% CrI: 0.44-1.07) for females. The probability that β-carotene intakes reduce the risk of any fracture and hip fracture by more than 20% was 95%. Conclusion The present meta-analysis suggests that β-carotene intake was inversely associated with fracture risk, consistently observed for case-control and cohort studies. Further randomized control trial is warranted to confirm this finding.