Burden of Uncontrolled Metabolic Risk Factors and Left Ventricular Structure and Function in Patients With Type 2...

Background Type 2 diabetes mellitus is closely associated with metabolic risk factors that all contribute to impairment of the left ventricle. The implications of having type 2 diabetes mellitus with well-controlled metabolic risk factors compared to an increasing burden of uncontrolled metabolic risk factors on left ventricular structure and function are not known. Methods and Results We compared patients with type 2 diabetes mellitus (n=751) with different degrees of uncontrolled metabolic risk factors present with a control group of individuals without present uncontrolled metabolic risk factors as recommended by the World Health Organization (n=80). In patients with well-controlled metabolic risk factors, only diastolic but neither structural nor systolic measures were impaired compared to the control group: the (early diastolic mitral inflow velocity)/(atrial diastolic mitral inflow velocity) ratio (median 0.94 [interquartile range 0.80, 1.08] versus 1.11 [0.85, 1.38], P<0.001), lateral early diastolic myocardial velocity at the level of the mitral annulus (mean 9.6 m/s [SD 2.5] versus 10.8 [3.5], P<0.001) and lateral (early diastolic mitral inflow velocity)/(early diastolic myocardial velocity at the level of the mitral annulus) (7.7 [6.5, 10.2] versus 6.3 [4.9, 7.8], P<0.001). With an increasing burden of uncontrolled metabolic risk factors, there were increased left ventricular mass index and wall thicknesses and impaired systolic function measured as global longitudinal strain: control group -15.9 (2.0); 0 uncontrolled risk factors -15.3 (2.4); 1 to 2 -14.6 (2.8); and ≥3 -14.0 (2.8), P<0.001. Within the diabetes mellitus group, there were uni- and multivariable associations of left ventricular measures and systolic blood pressure, body mass index, hemoglobin A_1c, and HDL -cholesterol. Conclusions In patients with type 2 diabetes mellitus, having well-controlled metabolic risk factors was associated with only left ventricular diastolic impairment but not with either structural or even subtle measures of systolic function. Increasing burden of uncontrolled metabolic risk factors was associated with structural and functional impairments.