SummaryBackground and objectives It has been suggested that moderate reductions in estimated GFR (eGFR) among older adults may not reflect chronic kidney disease (CKD).Design, setting, participants, & measurements We examined age-specific (Ͻ60, 60 to 69, 70 to 79, and Ն80 years) associations between eGFR level and six concurrent CKD complications among 30,528 participants from the National Health and Nutrition Examination Survey (NHANES) 1988(NHANES) to 1994(NHANES) and 1999(NHANES) to 2006 (n ϭ 8242 from NHANES 2003 to 2006 for hyperparathyroidism). Complications included anemia (hemoglobin Ͻ12 g/dl women, Ͻ13.5 g/dl men), acidosis (bicarbonate Ͻ22 mEq/L), hyperphosphatemia (phosphorus Ն4.5 mg/dl), hypoalbuminemia (albumin Ͻ3.5 mg/dl), hyperparathyroidism (intact parathyroid hormone Ն70 pg/ml), and hypertension (systolic/diastolic BP Ն140/90 mmHg or antihypertensive use).Results Among participants Ն80 years old, compared with those with estimated GFR (eGFR) Ն60 ml/min per 1.73 m 2 , the multivariable adjusted prevalence ratios (95% confidence interval) associated with eGFR levels of 45 to 59 and Ͻ45 ml/min per 1.73 m 2 were 1.39 (1.11 to1.73) and 2.06 (1.59 to 2.67) for anemia, 1.33 (0.89 to 1.98) and 2.47 (1.52 to 4.00) for acidosis, 1.11 (0.70 to 1.76) and 2.16 (1.36 to 3.42) for hyperphosphatemia, 2.04 (1.39 to 3.00) and 2.83 (1.76 to 4.53) for hyperparathyroidism and 1.09 (1.03 to 1.14), and 1.12 (1.05 to 1.19) for hypertension, respectively. Higher prevalence ratios for these complications at lower eGFR levels were also present at younger ages. Reduced eGFR was associated with hypoalbuminemia only for adults Ͻ70.
ConclusionsReduced eGFR was associated with a higher prevalence of several concurrent CKD complications, regardless of age.