Table 2.
CKD stage and objective assessments of cognitive function by levels of PA among participants ≥60 years of age from NHANES (2011–2014) (N = 3223).
| Overall, | Low physical activity, | High physical activity, | ||
|---|---|---|---|---|
| Stage and assessment | mean (95% CI) | mean (95% CI) | mean (95% CI) | P for interaction |
| Global cognitive function | ||||
| No CKD | 0 (ref) | 0 (ref) | 0 (ref) | |
| CKD stages G1–G3 | −0.07 (-0.15–0.00) | −0.13 (−0.21 to −0.05) | −0.01 (−0.11–0.08) | 0.03 |
| CKD stages G4 and G5 | −0.38 (−0.62 to −0.15) | −0.57 (−0.82 to −0.31) | 0.10 (−0.29–0.48) | 0.01 |
| Immediate recall (CERAD-WL) | ||||
| No CKD | 0 (ref) | 0 (ref) | 0 (ref) | |
| CKD stages G1–G3 | −0.10 (−0.19 to −0.00) | −0.17 (−0.31 to −0.02) | −0.03 (−0.19–0.14) | 0.24 |
| CKD stages G4 and G5 | −0.38 (−0.56 to −0.21) | −0.50 (−0.77 to −0.23) | −0.11 (−0.52–0.31) | 0.18 |
| Delayed recall (CERAD-DR) | ||||
| No CKD | 0 (ref) | 0 (ref) | 0 (ref) | |
| CKD stages G1–G3 | −0.03 (−0.14–0.08) | −0.10 (−0.25–0.04) | 0.05 (−0.11–0.21) | 0.13 |
| CKD stages G4 and G5 | −0.23 (−0.57–0.11) | −0.37 (−0.80–0.06) | 0.08 (−0.36–0.53) | 0.15 |
| Verbal fluency (AF) | ||||
| No CKD | 0 (ref) | 0 (ref) | 0 (ref) | |
| CKD stages G1–G3 | −0.09 (−0.19–0.01) | −0.13 (−0.25 to −0.00) | −0.05 (−0.18–0.07) | 0.34 |
| CKD stages G4 and G5 | −0.29 (−0.58 to −0.01) | −0.48 (−0.78 to −0.18) | 0.19 (−0.31–0.68) | 0.02 |
| Executive function and processing speed (DSST) | ||||
| No CKD | 0 (ref) | 0 (ref) | 0 (ref) | |
| CKD stages G1–G3 | −0.12 (−0.21 to −0.03) | −0.19 (−0.30 to −0.08) | −0.05 (−0.20–0.09) | 0.15 |
| CKD stages G4 and G5 | −0.54 (−0.93 to −0.16) | −0.75 (−1.18 to −0.32) | −0.01 (−0.51–0.50) | 0.02 |
Significant values (P < 0.05) are in bold.
Cognitive test scores are standardized to a mean of 0 and an SD of 1. Models are adjusted for age, sex, race, education, BMI, depressive symptoms, hypertension, diabetes, CHD, MI, stroke, anemia and smoking. NHANES sampling weights are accounted for in linear regression analyses to obtain nationally representative estimates. Serum creatinine was measured and used to calculate eGFR with the CKD-EPI equation. CKD stage was then defined by the following cut-points: no CKD: eGFR ≥60 mL/min/1.73 m2 and ACR <30 mg/g; CKD stages G1–G3: eGFR 30–59 mL/min/1.73 m2 or eGFR ≥60 mL/min/1.73 m2 and ACR ≥30 mg/g; CKD stages G4 and G5: eGFR <30 mL/min/1.73 m2. Physical activity was collected using the Global Physical Activity Questionnaire and converted to MET·min/week, where ≥600 MET·min/week represents high physical activity.