Association of neck, wrist and hip circumferences with kidney function in children and adolescents: the CASPIAN- V study

INTRODUCTION: Some evidence exists on the relationship between anthropometric measures and chronic kidney disease. This study aims to investigate the association of neck, wrist and hip circumferences with kidney function in a pediatric population.
METHODS: In this national study, 4200 students aged 7-18 years were selected by random cluster sampling from 30 provinces of Iran. Neck circumference (NC), wrist (WC) and hip (HC) were measured according to standard protocol and were categorized to low and high according to their age-sex specific median values. The estimated glomerular filtration rate (eGFR) was calculated based on the "updated" Schwartz equation.
RESULTS: The response rate was 91.5% (n=3843). The mean (SD) of eGFR was 96.71(19.46), 96.49(21.69), and 96.59 (20.66) ml/min/1.73 m2 for girls, boys and total population, respectively. Compared to other participants, those in the high NC group had significantly higher eGFR [102.12 ±21.31 vs.90.65±18.18, p <0.001] and Cr [high; 0.66± 0.14 vs.0.63 ±0.11mg/dL, p <0.001]. Individuals categorized as high WC had significantly higher eGFR [102.12 ±21.31 vs. 90.83 ±18.16, p <0.001] and Cr [0.66 ±0.15vs. 0.63 ±0.10) mg/dL, p <0.001]. In multivariate model, high NC, WC and HC were associated with higher eGFR (P < 0.001). Moreover, each one unit (cm) increment in NC, WC and HC increased eGFR by 1.42, 3.24 and 0.46 unit, respectively.
DISCUSSION AND CONCLUSION: The findings of this large population-based study suggest that simple anthropometric measures, as wrist and neck circumferences, can be used in epidemiological studies to determine the children and adolescents that might be at risk of kidney dysfunction.