Effects of obesity and metabolic syndrome on cardiovascular outcomes in pediatric kidney transplant recipients: a longitudinal study
Obesity and metabolic syndrome (MS) are common after kidney transplantation, but their contribution to adverse cardiovascular (CV) outcomes in children are not well known. A prospective, controlled, longitudinal cohort study was conducted to investigate the effects of obesity and MS on left ventricular hypertrophy (LVH) and myocardial strain in pediatric kidney transplant recipients.
Transplant recipients (n = 42) had anthropometrics [body mass index (BMI), waist circumference, waist-to-height ratio], biochemical parameters (fasting glucose, lipid panel, HbA1c%), and echocardiogram with speckle tracking analysis for strain measured at 1, 18, and 30 months post-transplant. Additionally, 35 pre-transplant echocardiograms were analyzed retrospectively. Healthy children (n = 24) served as controls.
Waist-to-height ratio detected abdominal obesity in 46% of transplant patients, whereas only 8.1% were identified as obese by waist circumference. Ejection fraction and fractional shortening of the transplant group were normal. Prevalence of LVH was 35.2%, 17.1%, and 35.5% at 1, 18, and 30 months respectively. The longitudinal strain of transplant group was worse than controls at all time points (p < 0.001). Hemodialysis was independently associated with 21% worse longitudinal strain during the pre-transplant period (p = 0.04). After transplantation, obesity, MS, and systolic hypertension predicted increased odds of LVH (p < 0.04). Worse longitudinal strain was independently associated with obesity, MS, hypertension, and the combination of MS with elevated low density lipoprotein (LDL) cholesterol (p < 0.04), whereas higher estimated glomerular filtration rate (eGFR) conferred a protective effect (p < 0.001).
Obesity and MS adversely affect CV outcomes after transplantation. Further studies are needed to investigate speckle tracking echocardiography as a tool for early detection of subclinical myocardial dysfunction in this population.
KeywordsCarotid intima-media thickness Myocardial strain Speckle tracking echocardiography Left ventricular hypertrophy Dyslipidemia Hypertension
Compliance with ethical standards
Approval was obtained from the Institutional Review Board (IRB) at Children’s National. Informed consent was obtained from all participants and the study was performed in accordance with the Declaration of Helsinki.
Conflicts of interest
The authors declare that they have no conflicts of interest.
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