Author contributions
WG
Study concept and design: YH; HL; JK; SZ and WG; Recruiting and supporting participants: HL; YX; JW; YL and ZW; Data analysis and interpretation: YH; TL; PL; ZH; FL and WG; Drafting the manuscript: YH and SZ; Critical revision of the manuscript for intellectual content: YH, SZ and WG.