The NHANES (National Health and Nutrition Examination Survey) is a nationally representative, cross-sectional survey that is currently conducted every 2 years by the Centers for Disease Control and Prevention's National Center for Health Statistics to examine disease prevalence and trends over time in noninstitutionalized U.S. civilian residents.
Obesity is a risk factor for both diabetes and hypertension, the two main causes of CKD among adults in the United States. Additionally, there is some evidence that obesity is an independent risk factor for CKD (Eknoyan, 2011; Hsu et al., 2006; Gelber et al., 2005; Foster et al., 2008), although some of the risk may be explained by shared CVD risk factors (Sowers et al., 2011). Particularly, abdominal obesity has been shown to be associated with increased prevalence of proteinuria but not necessarily associated with CKD progression or decline in renal function (Bonnet et al., 2006; Lea et al., 2008; deBoer et al., 2007). Since obesity appears to increase the likelihood of both CKD and CKD risk factors, assessing the burden of this risk factor is important in CKD surveillance. The survey consists of a standardized in-home interview and a physical examination and blood and urine collection at a mobile examination center (MEC). Here we examined data from the 1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, 2009-2010, 2011-2012, 2013-2014, and 2015-2016 NHANES. Both body mass index (BMI) and waist circumference were measured in non-pregnant adult (20+) participants. Overweight and obesity were defined by BMI ≥25 and ≥30 kg/m². Abdominal obesity were defined by waist circumference measurements of >102 cm (~40 inches) and >88 cm (~35 inches) for men and women, respectively.