Background This cross-sectional study evaluated associations between structural and functional measures of left ventricular diastolic function and cardiorespiratory fitness (CRF) in a well-characterized population-based cohort stratified according to glucose metabolism status. Methods and Results Six hundred seventy-two participants from The Maastricht Study (mean±SD age, 61±9 years; 17.4% prediabetes and 25.4% type 2 diabetes mellitus) underwent both echocardiography to determine left atrial volume index, left ventricular mass index, maximum tricuspid flow regurgitation, average e' and E/e' ratio; and submaximal cycle ergometer test to determine CRF as maximum power output per kilogram body mass. Associations were examined with linear regression adjusted for cardiovascular risk and lifestyle factors, and interaction terms. After adjustment, in normal glucose metabolism but not (pre)diabetes, higher left atrial volume index (per 1 mL/m2), left ventricular mass index (per 1 g/m2.7), maximum tricuspid regurgitation flow (per 1 m/s) were associated with higher CRF (maximum power output per kilogram body mass; β in normal glucose metabolism 0.015 [0.008-0.023], Pinteraction (pre)diabetes <0.10; 0.007 [-0.001 to 0.015], Pinteraction type 2 diabetes mellitus <0.10; 0.129 [0.011-0.246], Pinteraction >0.10; for left atrial volume index, left ventricular mass index, maximum tricuspid regurgitation flow, respectively). Furthermore, after adjustment, in all individuals, higher average E/e' ratio (per unit), but not average e', was associated with lower CRF (normal glucose metabolism -0.044 [-0.071 to -0.016]), Pinteraction >0.10). Conclusions In this population-based study, structural and functional measures of left ventricular diastolic function were independently differentially associated with CRF over the strata of glucose metabolism status. This suggests that deteriorating left ventricular diastolic function, although of small effect, may contribute to the pathophysiological process of impaired CRF in the general population. Moreover, the differential effects in these structural measures may be the consequence of cardiac structural adaptation to effectively increase CRF in normal glucose metabolism, which is absent in (pre)diabetes.
Keywords: cardiorespiratory fitness; left ventricular diastolic dysfunction; physical fitness; population‐based; prediabetes; type 2 diabetes mellitus.