Q) Quite a few of my teenage patients are overweight. I know they are at risk for diabetes, but does their weight also affect their kidneys? Isn’t diabetes the main cause of kidney failure?
The number one cause of chronic kidney disease (CKD) in the United States and worldwide is diabetes, but it is certainly not the only risk factor. Studies have shown a link between obesity and CKD; even in the absence of kidney disease, obesity may cause glomerular dysfunction and an increase in glomerular size.1
Obesity during adolescence has been identified as a strong predictor of CKD in adulthood. Other diseases and conditions that, if present in adolescence, indicate future risk for kidney disease include diabetes, hypertension, inflammation, and proteinuria.
A recent Swedish study followed patients from adolescence to adulthood to identify markers that would predict later kidney disease. In this study, the most predictive factor of kidney failure in adulthood was proteinuria in adolescence (odds ratio, 7.72). These results may be limited by the homogeneity of the predominantly white, male study population, but the extensive follow-up period, which “highlights the long natural history” of kidney disease, is one strength of this study.2
Based on these and other findings, you know that if your teenage patients have proteinuria, they are much more likely to develop kidney failure as an adult. Yet, in the US, the American Academy of Pediatrics and the US Preventive Services Task Force do not recommend urine screening for asymptomatic children.3
Interestingly, however, a survey of pediatric practices revealed that 58% of pediatricians screen adolescents with urinalysis, even if they are asymptomatic.4 In other words, they ignore the guidelines. If they did not, we would likely miss what is possibly the most important predictive factor for kidney failure in adults. —TAH
Tia Austin Hayes, FNP-C
UMMC/JMM Outpatient Dialysis/Renal Clinic, Jackson, Mississippi
REFERENCES
1. Rocchini A. Childhood obesity and a diabetes epidemic. N Engl J Med. 2002;346(11):854-855.
2. Sundin PO, Udumyan R, Sjöström P, Montgomery S. Predictors in adolescence of ESRD in middle-aged men. Am J Kidney Dis. 2014;64(5):723-729.
3. Kaplan RE, Springate JE, Feld LG. Screening dipstick urinalysis: a time to change. Pediatrics. 1997;100(6):919-921.
4. Sox CM, Christakis DA. Pediatricians’ screening urinalysis practices. J Pediatr. 2005; 147(3):362-365.
The author would like to thank Eric Judd, MD, of the University of Alabama at Birmingham, for his advice on the preparation of this response.