Differential associations between glomerular filtration rate and duration of obesity depending on the presence or absence of left ventricular diastolic dysfunction

• There is no consensus formula for measuring glomerular filtration rate in obesity.
• Obesity is not always associated with renal hyperfiltration.
• Obesity-associated diastolic dysfunction may precede chronic kidney disease.

BackgroundA robust and consistent association between increasing body mass index (BMI) and chronic kidney disease (CKD) has been reported in several observational studies. Obesity remains the main preventable risk factor for CKD because it largely mediates diabetes and hypertension, the 2 most common etiologies for end-stage kidney disease (ESKD). Obesity is associated weakly with early stages of kidney disease but strongly with kidney progression to ESKD, even after adjustment for hypertension and diabetes.AimTo assess the relationship between estimated glomerular filtration rate (eGFR) and trans-thoracic echocardiography left ventricular function parameters in a cohort of patients with obesity.Materials & methodsCross-sectional study involving 324 obese (BMI = 44.0 ± 2.2 Kg/m2) apparently healthy asymptomatic patients with an eGFR > 60 ml/min/1.73 m2. Each patient underwent transthoracic echocardiography and a blood testing. The eGFR was addressed by the CKD-EPI formula.ResultsAll patients had a normal systolic function whereas 24.5% disclosed diastolic dysfunction (DD). Hypertension and type 2 diabetes mellitus prevalence were 34.5% and 4.5% (respectively). All patients disclosed an eGFR > 60 ml/min while none of them disclosed hyperfiltration (eGFR > 120 ml/min). eGFR correlated inversely with BMI and the duration of obesity and positively with diastolic function parameters (P < 0.001 for all, respectively). Patients with diastolic dysfunction displayed lower eGFR (P < 0.0005) and longer duration of obesity (P < 0.0005).ConclusionsObesity and its duration are likely to impose hemodynamic changes affecting simultaneously both heart (diastolic dysfunction) and kidney (decreased glomerular filtration rate). Larger prospective studies are warranted.