December 2007: Volume 33, Number 12
Patient Awareness Trails Rising CKD Prevalence
More than 13% of the U.S. population now has chronic kidney disease, a 3% increase over the last decade, yet most individuals with the disease remain unaware of it—even those with reduced kidney function and albuminuria, according to a new study published in the Journal of the American Medical Association (2007; 298(17): 2038–2047).
The researchers did a cross-sectional analysis of 1988–1994 and 1999–2004 NHANES data, comprised of a nationally representative sample of adults age 20 years and older, to determine the distribution of CKD stages and severity. Overall, the study found that prevalence of CKD stages 1 to 4 increased from 10% in 1988–1994 to 13.1% in 1999–2004, with corresponding increases in mild, moderate, and severely reduced eGFR, from 42.4% to 51.2%, 5.4% to 7.7%, and 0.21% to 0.35%, respectively. The trend was the same in all age groups (See Graph, below). In addition, prevalence of microalbuminuria increased from 7.1% to 8.2%, with a modest increase in macroalbuminuria that fell within the limits of random variation.
Demographic analysis of sex and racial groups showed increases in all categories. Prevalence among men increased from 8.2% to 11.1% and among women from 12.1% to 15%. For non-Hispanic whites, prevalence changed from 10.5% to 13.8%, for non-Hispanic Blacks from 10.2% to 11.7%, and among Mexican Americans 6.3% to 8%. The authors observed that despite adjusting their study for changes in the demographic makeup of the U.S. over the time period, differences remained substantial.
While higher prevalence of risk factors for CKD—diabetes, hypertension, and obesity—partially accounted for the overall increased prevalence of decreased eGFR, the increase in prevalence of albuminuria was entirely explained by these risk factors. Moreover, the researchers found that the proportion of those who said they knew they had weak or failing kidneys was very low, with only 42% of those at stage 4 reporting being aware of their disease.
Noting the particularly high prevalence of CKD in older populations and those with hypertension and diabetes, the researchers urge stakeholders to make CKD awareness more central to future public health planning.