Prevalence of high blood pressure and elevated serum creatinine level in the United States -: Findings from the Third National Health and Nutrition Examination Survey (1988-1994)

Background: The prevalence and incidence of endstage renal disease in the United States are increasing, but milder renal disease is much more common and may often go undiagnosed and undertreated. Methods: A cross-sectional study of a representative sample of the US population was conducted using 16589 adult participants aged 17 years and older in the Third National Health and Nutrition Examination Survey (NHANES III) conducted from 1988 to 1994. An elevated serum creatinine level was defined as 141 mu mol/L or higher (greater than or equal to1.6 mg/dL) for men and 124 mu mol/L or higher (greater than or equal to1.4 mg/dL) for women (>99th percentile for healthy young adults) and was the main outcome measure. Results: Higher systolic and diastolic blood pressures, presence of hypertension, antihypertensive medication use, older age, and diabetes mellitus were all associated with higher serum creatinine levels. An estimated 3.0% (5.6 million) of the civilian, noninstitutionalized US population had elevated serum creatinine levels, 70% of whom were hypertensive. Among hypertensive individuals with an elevated serum creatinine level, 75% received treatment. However, only 11% of all individuals with hypertension had their blood pressure reduced to lower than 130/85 mm Hg (the Sixth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure recommendation for hypertensive individuals with renal disease); 27% had a blood pressure lower than 140/90 mm Hg. Treated hypertensive individuals with an elevated creatinine level had a mean blood pressure of 147/77 mm Hg, 48% of whom were prescribed one antihypertensive medication. Conclusion: Elevated serum creatinine level, an indicator of chronic renal disease, is common and strongly related to inadequate treatment of high blood pressure.