Obesity clearly associated to kidney disease in adult population; however, there is scarce evidence in children and adolescents. The aim was to compare frequency of renal damage according to the presence of overweight-obesity in children and adolescents, as well as to compare nutritional and biochemical risk factors, according to the presence of kidney alterations.

Children who are obese or overweight may be at higher risk for kidney alterations; and kidney disease risk factors, a recently published cross-sectional study suggests. “These findings must alert public health authorities to implement appropriate screening programs for timely detection and treatment of kidney disease and to design prevention programs to avoid obesity and its complications, especially in [the] pediatric population,” the authors wrote. “These actions may help to counteract the current epidemic of CKD in the world.”

Obese and overweight children

Researchers examined 172 children from a primary health care unit aged 6 to 16 who without diabetes mellitus, malnutrition; hypertension or independent comorbid conditions associated with obesity or kidney disease and transitory causes of microalbuminuria. Participants classified as normal, overweight or obese based on BMI, and kidney alterations defined by decreases in glomerular filtration rate (<90 mL/min/1.73m2), hyperfiltration (>170 mL/min/1.73m2) and macroalbuminuria (30 to 300mg/g).

Of the sample population, 41% were classified as obese, 32% were classified as overweight and 27% were classified as normal. Obese and overweight children had significantly higher abdominal obesity (0% vs. 69%), hypertriglyceridemia (11% vs. 47%), high LDL cholesterol (2% vs. 8%), low HDL cholesterol (2% vs. 28%), hypertension (19% vs. 26%), hyperinsulinemia (8% vs. 70%) and hyperuricemia (11% vs. 28%) than the normal BMI group.

No kidney alterations found in participants with normal BMI; while 3.6% of overweight subjects and 9.9% of obese subjects showed alterations. Obese children also displayed a higher proportion of higher systolic BP and family history of obesity, as well as a nonsignificant trend to higher diastolic BP, birth weight and sedentary activities. No other trends were observed in participants’ age, gender, diabetic family history, hypertension or kidney disease.

Presence of kidney alterations

Hyperfiltration and MA present in 5 and 4 subjects with overweight/obesity, respectively, whereas decreased GFR present in only 1 subject with obesity. Normal weight subjects had no kidney alterations. In multivariate analysis, kidney alterations significantly predicted by higher BMI and lower HDL-cholesterol.

“Higher BMI and lower HDL cholesterol levels were the only significant predicting factors for the presence of kidney alterations,” the researchers wrote. “Further investigations with an epidemiological design are needed to confirm our findings and, particularly longitudinal studies, to identify if those children and adolescents with kidney alterations progress to CKD or end-stage renal disease.”