Cystatin C, cardiometabolic risk, and body composition in severely obese children

Abstract

The aim of this study was to assess the relationship between cystatin C (CysC), cardiometabolic risk factors (CMRFs), and body composition in severely obese children. We evaluated 117 children aged 7-14 years old. Seventy-nine of these were severely obese (body mass index z-score ranging from 2.1 to 8.4), and 38 were children with normal nutrition state. CysC was determined by immunonephelometry. CMRFs (glucose, insulin, high-density lipoprotein cholesterol, triglycerides, homocysteine, uric acid, alanine aminotransferase, and high-sensitivity C-reactive protein) were measured by standard biochemical methods. Blood pressure was evaluated at the clinical examination. Renal function was estimated using the glomerular filtration rate (eGFR) based upon creatinine levels, and body weight (Léger formula). Body composition was assessed by segmental bioelectrical impedance. Obese children at the highest tertile of CysC values were characterized by their aggregation of CMRFs. CysC concentration was associated with insulin resistance, alanine aminotransferase, uric acid, and homocysteine after adjusting for age, gender, and eGFR. CysC values were also correlated with the fat-free mass and specifically with skeletal muscle mass. CysC levels were correlated with CMRFs factors independently of renal function, and affected by skeletal muscle mass in severely obese children, although they are less influenced by this than is creatinine.

NGAL and cystatin C: two possible early markers of diabetic nephropathy in young patients with type 1 diabetes mellitus: one year follow up

“…29,30 Moreover, increased CysC values are associated with increased cardiovascular morbidity risk and atherosclerosis progression in both T1D patients and severely obese children. 31,32 Glomerular filtration rate (GFR) is best evaluated by the clearance of iohexol (iGFR). 32,33 Alternatively, in children, the 2009 modified Schwartz bedside GFR formula has been widely adopted because it has been strongly correlated to iGFR.…”

“…31,32 Glomerular filtration rate (GFR) is best evaluated by the clearance of iohexol (iGFR). 32,33 Alternatively, in children, the 2009 modified Schwartz bedside GFR formula has been widely adopted because it has been strongly correlated to iGFR. 34,35 Moreover, formulas that assess both creatinine and cystatin C, like the Lund strategy (L-eGFR), 36 are considered to provide more accurate and reliable estimation of the GFR.…”

Decreased renal function in overweight and obese prepubertal children

“…Though, studies in adults showed that CysC levels are increased in obese subjects (13,14) and that CysC-based formulas may result in an underestimation of GFR in patients with higher BMI (15). Few studies exist on CysC levels in children, leaving a large uncertainty regarding the influence of body composition in the interpretation of CysC levels (16).…”

Obesity is a Risk Factor for Renal Toxicity and Wound Complications among a Cohort of Pediatric Cancer Patients at a Single Tertiary Care Institution

“…While many of these inflammatory markers and cytokines have been identified in animal models of obesity, they remain largely investigational and their clinical utility at this time is unknown. More clinically relevant, the impact of obesity on renal dysfunction has evolved with the identification of urinary cystatin C (Cys-C) as a correlate marker for glomerular filtration rate (GFR) [32,33]. While markers of inflammation including Cys-C were not evaluated in our cohort, we did identify an increased risk of renal toxicity based upon serum creatinine values in the obese patients.…”