Background:
Obesity has become a national epidemic, and is associated with increased risk for comorbid diseases including end-stage renal disease (ESRD). Among ESRD patients, obesity may improve dialysis-survival but decreases likelihood of transplantation, and as such, obesity prevalence may directly impact growth of the incident dialysis population.
Methods:
Incident adult ESRD patients with complete body mass index (BMI, kg/m
2
) data were identified from the United States Renal Data System from 01/01/1995-12/31/2010 (n=1,822,598). Data from the Behavioral Risk Factor Surveillance System of the Centers for Disease Control and Prevention (n=4,303,471) represented the US population when weighted. Trends in BMI and obesity classes I (BMI of 30-34.9), II (BMI of 35-39.9), and III (BMI ≥40) were examined by year of dialysis initiation. Trends in median BMI slope were compared between the ESRD and US populations using linear regression.
Results:
Median BMI of ESRD patients in 1995 was 24.2 as compared to 28.0 in 2010, a 15.7% increase, while the US population’s median BMI increased from 24.2 in 1995 to 25.6 in 2010, a 5.8% increase. Comparable trends were noted with respect to prevalence of obesity classes I, II, and III (Table). BMI increase among the ESRD population was significantly more rapid than among the US population (β: 0.15, 95% CI: 0.14-0.17, p<0.001) (Figure).
Conclusion:
The median BMI of ESRD patients and prevalence of obesity among ESRD patients is increasing more rapidly than the US population. Given the increased dialysis-survival and decreased likelihood of transplantation associated with obesity, healthcare costs will likely increase, and thus, future research should be directed at examining medical expenditures.
What is a cohort effect? Comparison of three statistical methods for modeling cohort effects in obesity prevalence in the United States, 1971–2006