Background: Evidence associates obesity with glomerular hyperperfusion. Concurrent inflammation, hypertension, dyslipidemia, and insulin resistance represent further established risks to renal health in both children and adults.
Objective and hypotheses: To investigate the relationship between childhood obesity and risk of renal impairment.
Method: A total of 114 (38.6% boys) obese according to the IOTF reference but otherwise healthy children, who were investigated in 2013, were included in the study (mean age 11.5±3.6). Body weight, height, waist circumference (WC), and blood pressure (BP) were measured using standard procedures. The pubertal status was defined applying Tanner scale. Blood and urine samples were collected after overnight fast. Kidney size was measured by standard abdominal echography; kidney volume and glomerular filtration rate (Schwartz formula, adjusted to ml/min per 1.73 m2) were calculated.
Results: Microalbuminuria (MA) was detected in 8.5% of the children, and 40.2% of all were with high systolic BP. Close to half of the children (43.4%) showed insulin resistance (assessed by HOMA-IR) and 95.4% displayed hyperinsulinism. High hsCRP was present in 32.5%. Elevated LDL-cholesterol was found in 42.1% of the children, with high total cholesterol in 6.2% of all. Kidney volume correlated with WC (left r=0.488, P<0.001; right r=0.292, P=0.021), as well as with weight and elevated systolic BP. Children with hyperfiltration (9.6% of all) are booked for poor metabolic health as at this stage they all had elevated total cholesterol and triglycerides. In further 14.3% of the children (all pubertal) glomerular filtration rate was low, and they had significantly larger kidney volume (left P<0.001; right P=0.004), HOMA-IR (P=0.001), WC and BMI (P<0.001) compared to those with normal and hyperfiltration rate.
Conclusion: To summarize, childhood obesity showed association with established risk factors for renal toxicity. Whether kidney volume in obese children has an independent predictive value of future chronic kidney disease remains to be investigated.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology