Influence of obesity on kidneys of children

Incidence of nephropathy that increases recently became a global public health problem. It is important to determine the modifiable risk factors in order to develop preventive strategy for recently encountered nephropathy cases. Epidemiological studies indicate that obesity increases nephropathy risk and affect the prognoses. Most of the studies performed for correlation between obesity and nephropathy are carried out on adults. The studies which research about the influence of obesity on nephropathy in children are rather few. Start of nephropathy as a result of obesity is actually asymptomatic and insidious. Glomerulopathy(ORG) which is accepted to be in correlation with obesity describes glomerulopathy that develops secondary to obesity without primer glomerulosclerosis. Pathophysiological mechanism of ORG could not have been understood exactly yet. In the studies on kidney damage as a result of obesity, glomerular level damages are mostly focused on, and studies on tubulupaty development are very limited. Nephropathy correlated with obesity is morphologically seen as focal segmental glomerulosclerosis or glomerulomegali. Our objective in our studies is to research the influence of obesity on nephropathy in obese children and to compare the kidney damage indicators with reference markers. Study group was constituted of 43 obese children who have applied to the children health and pediatric clinic whose body mass indexes (BMI) are ≥ 95 without any known diseases, with no medicine administration between the ages of 6-18 and 43 healthy children whose body mass indexes (BMI) are ≥ 85 without any chronic diseases, with same socio-demographical characteristics and gender were included in the study as control group. Measurement of weight, height, waist circumference, hip circumference, blood pressure was performed in all patients and control group and their waist hip proportions were calculated. The creatine, cystatinC levels in the blood and microalbumin, protein, N-acetyl-β-D glucoseaminidase (NAG), sodium and transforming growth factor Beta (TGF-β )levels in urine within 24 hours were examined. Glomerular filtration speed (GFH) was calculated by using Schwartz formula. Kidney dimensions and volumes were measured by ultrasonography. In statistical assessments chi-square, t-test, Mann Whitney U were used and in order to examine the correlation of the variables with each other Pearson Correlation andKendall'stau-b tests were used. p<0,005 values were found significant statistically. As a result of our assessments the waist hip ratio, systolic and diastolic blood pressures, protein, micro albumin and sodium discharge in urine in 24 hours and right kidney volume percentiles were found to have high significance.No significance determined in the results of serum cystatinC, serum creatinine, GFH, TGF-β andNAG discharge in urine in 24 hours between the two groups. There was positive correlation between the body mass index and cistolic and diastolic blood pressures, GFH, micro albumin, sodium, right and left kidney volumes of control group. The correlation between the waist hip ratio and systolic and diastolic blood pressure were found significant. There was positive correlation between GFH and both kidney volumes. There was positive correlation between systolic and diastolic blood pressure and both kidney volumes.There was positive correlation between systolic and diastolic blood pressureand sodium and micro albumin. Conclusively, micro albumin can be used as the early marker of glomerular damage in nephropathy related to obesity in children and sodium discharge in urine in 24 hours can be used as the early marker of tubular damage. Since the kidney volume of obese children is found significantly high in comparison to control group, it is concluded that ORG develops as glomerulomegali in the early ages of childhood and may develop further as glomerulosclerosiswith increasing age. It is indicated that obesity is a particular risk in development of hypertension. Since arterial blood pressures, urine protein,sodium discharge are correlated with Waist Hip Ratio it is concluded that central obesity may cause more nephropathy diseases.