Fig. 1: Circulating FGF21 levels are increased in subjects with HFpEF.

A Serum FGF21 levels of patients with HFpEF and healthy subjects were measured by immunoassay (HFpEF, n = 151; healthy, n = 146). B, C Correlation analysis between LogFGF21 and LogBNP, as well as left ventricular ejection fraction (LVEF) in subjects with HFpEF. (B, n = 151; C, n = 147). D Left ventricular systolic function of WT mice with HFpEF and controls. Top, M-mode echocardiographic tracings; Bottom, quantification of LVEF and left ventricular fractional shortening (LVFS). n = 6 mice per condition. E Left ventricular diastolic function. Top, pulsed-wave Doppler (top) and tissue Doppler (bottom) tracings of WT mice with or without HFpEF. Bottom, quantification of the ratio between the mitral E wave and A wave (E/A), and the mitral E wave and E′ wave (E/E′). n = 6 mice per condition. The lung weight to tibia length ratio (LW/TL, F) and the running distance during exercise exhaustion test (G) of WT mice with or without HFpEF. n = 6 mice per condition. H Serum FGF21 levels of WT mice with HFpEF and controls were measured by immunoassay. n = 6 mice per condition. FGF21 contents in epididymal white adipose tissue (eWAT, I), subcutaneous white adipose tissue (scWAT, J), liver (K), and heart (L) of mice with HFpEF and controls were tested by immunoblot, respectively. n = 6 mice per condition. Violin plots in (A) are presented as lines indicating the median and interquartile range. Bar graphs in (D–L) are shown as mean ± SEM. Statistical significance was determined by the two-sided Mann–Whitney U test (A), two-tailed unpaired Student’s t test (D–G, I–L), or two-tailed unpaired Student’s t test with Welch’s correction (H). The associations between cardiac function parameters and serum levels of FGF21 were estimated by Pearson correlation analysis (B, C).