With adjustment for age, prevalence of hypertension by self-report or measured blood pressure ≥140/≥90 mmHg in the United States CKD population was 59.1% for the period 2013-2014.
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.
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, and 2013-2014 NHANES. CKD was diagnosed by laboratory testing and defined as an eGFR of ≥60 ml/min/1.73 m² and the presence of albuminuria (first single measurement of albumin:creatinine ratio from random spot urine) or by eGFR alone for CKD stage 3 or 4 (stage 5 was excluded).
Hypertension is the second leading cause of CKD. Hypertensive disease accounts for 28% of incident ESRD in the United States (U.S. Renal Data System, 2011). Hypertension is associated with higher risk of cardiovascular outcomes in those with CKD. Additionally, treatment of hypertension in CKD, particularly by ACE inhibitors, has been shown to decrease proteinuria and disease progression (Sarafidis et al., 2008). Thus, assessing the prevalence of this risk factor and its control is essential to CKD surveillance. Self-reported hypertension was defined by answer of “yes” to the question “Have you ever been told by a doctor or other health professional that you have hypertension, or high blood pressure?” Blood pressure measurements were taken by standardized protocol during the MEC and the average value (up to four measurements) was used. Hypertension medications were recorded from prescription bottles during the interview.
|Description of Measure||Prevalence of hypertension and blood pressure control in the adult CKD population; analysis is adjusted for age|
|Type of Data Source||Public|
|Health Care System Data||No|
|Regional or National?||National|
|Demographic Group||Noninstitutionalized U.S. residents aged 20+ years|
|Numerator||Participants with self-report, high (>140/90) blood pressure measurements, or hypertension drug use. |
|Denominator||Participants with CKD|
|Definition of CKD||eGFR ≥ 90 ml/min/1.73 m² and estimated persistent albuminuria; eGFR 60-89 ml/min/1.73 m² and estimated persistent albuminuria; Stage 3, eGFR 30-59 ml/min/1.73 m²; Stage 4, 15-29 ml/min/1.73 m²; Stage 5, excluded|
|Glomerular filtration rate||Estimated using MDRD Study equation for calibrated creatinine: eGFR=175 × [(calibrated serum creatinine in mg/dl)-1.154] × age-0.203 × (0.742 if female) × (1.210 if African-American)|
|Proteinuria||Urinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant/menstruating women excluded|
|Primary Data Source Indicator||bpq020: “Have you ever been told by a doctor or health professional that you have high blood pressure?” yes/no|
|Primary Indicator Method of Measurement||Questionnaire (interviewer-administered); ages 16+|
|Secondary (1) Variable||bpxsy1-bpxsy4: Up to four blood pressure measurements|
|Secondary (1) Indicator Method of Measurement||Examination/Laboratory|
|Secondary (2) Variable||nhcode/rxddrgid: generic drug codes|
|Secondary (2) Indicator Method of Measuremenr||Questionnaire (interviewer-administered), with recording of medications from Rx bottles|
|Frequency of Measurement (Primary)||Once (cross-sectional)|
|U.S. Region Covered by Primary Variable||All|
|Period Currently Available||1999–2014|
|Additional Data Items of Interest||Stage of CKD, stratification variables of interest (age, gender, race/ethnicity, BMI, hypertension by self-report)|
|Limitations of Indicator||Albuminuria and kidney function can only be assessed from a one-time cross-sectional measurement, leading to overestimation of prevalence; second measures of albuminuria are available for only 2009-2010 and were first-morning rather than spot urine samples; no second measures of creatinine|
|Analytic Considerations||Appropriate NHANES survey weights must be used for all analyses; creatinine measurements must be calibrated for NHANES III, 1999-2000 and 2005-2006; many variable names differ across surveys; if SE 30% or more of estimate, must report as “low precision”|