Table 4.
Association between changes in renal function and change in blood lead
| Variables | Unadjusted |
Adjusted |
Fully adjusted |
|||
|---|---|---|---|---|---|---|
| β (95% CI) | P value | β (95% CI) | P value | β (95% CI) | P value | |
| SCRT, ×10−2 mg/dl | 0.28 (−1.37 to 1.92) | 0.74 | 0.74 (−0.74 to 2.23) | 0.32 | 0.72 (−0.81 to 2.26) | 0.35 |
| Serum cystatin C, ×10−2 mg/l | 0.65 (−0.89 to 2.19) | 0.41 | 1.05 (−0.42 to 2.52) | 0.16 | 1.18 (−0.33 to 2.68) | 0.12 |
| eGFRcrt, ml/min per 1.73 m2 | −0.43 (−2.08 to 1.23) | 0.61 | −0.86 (−2.34 to 0.61) | 0.25 | −0.86 (−2.39 to 0.67) | 0.27 |
| eGFRcys, ml/min per 1.73 m2 | −0.88 (−2.67 to 0.91) | 0.33 | −1.42 (−3.13 to 0.30) | 0.11 | −1.58 (−3.34 to 0.18) | 0.078 |
| eGFRcc, ml/min per 1.73 m2 | −0.75 (−2.21 to 0.71) | 0.31 | −1.21 (−2.51 to 0.09) | 0.069 | −1.32 (−2.66 to 0.03) | 0.055 |
| Serum osmolality, mOsm/kg | 0.08 (−0.57 to 0.74) | 0.80 | 0.02 (−0.47 to 0.50) | 0.95 | −0.05 (−0.55 to 0.46) | 0.85 |
| Serum sodium, mmol/l | 0.13 (−0.19 to 0.45) | 0.42 | 0.09 (−0.16 to 0.34) | 0.48 | 0.06 (−0.20 to 0.31) | 0.66 |
| Blood glucose, mg/dl | −2.19 (−4.67 to 0.29) | 0.084 | −0.78 (−2.91 to 1.34) | 0.47 | −0.93 (−3.07 to 1.22) | 0.40 |
| Insulin, % | −4.44 (−15.4 to 7.94) | 0.46 | −4.30 (−14.6 to 7.26) | 0.45 | −3.75 (−13.6 to 7.19) | 0.48 |
| BUN, mg/dl | −0.13 (−0.63 to 0.38) | 0.62 | −0.18 (−0.61 to 0.25) | 0.40 | −0.13 (−0.57 to 0.32) | 0.57 |
| BUN-to-SCRT ratio | −0.23 (−0.76 to 0.29) | 0.38 | −0.40 (−0.83 to 0.03) | 0.067 | −0.35 (−0.80 to 0.09) | 0.12 |
| Urine specific gravity, ×10−2 | −0.03 (−0.14 to 0.09) | 0.65 | −0.03 (−0.11 to 0.06) | 0.54 | −0.00 (−0.09 to 0.08) | 0.94 |
| ACR, % | 1.31 (−8.03 to 11.6) | 0.79 | −0.37 (−8.34 to 8.29) | 0.93 | 0.23 (−7.94 to 9.12) | 0.96 |
ACR, albumin-to-creatinine ratio; BUN, blood urea nitrogen; eGFR, estimated glomerular filtration rate; eGFRcc, eGFR derived from SCRT and cystatin C; eGFRcrt, eGFR derived from SCRT; eGFRcys, eGFR derived from cystatin C; HDL, high-density lipoprotein; SCRT, serum creatinine.
eGFRcrt, eGFRcys, and eGFRcc refer to the glomerular filtration rate estimated from SCRT, serum cystatin C, or both, respectively.18 Changes in serum insulin and the urinary ACR are expressed as percentage differences from baseline to follow-up. Association sizes (β), given with 95% CI, express the change in the dependent variable for a 3-fold increase in the blood lead concentration. Adjusted models accounted for sex, age, follow-up duration, the time of day of blood sampling (nighttime vs. daytime), and the baseline renal function measure being analyzed. Fully adjusted models additionally accounted for baseline body mass index, change in body weight, and the baseline values of and changes during follow-up in smoking status, mean arterial pressure, antihypertensive medication (yes vs. no), the total-to-HDL cholesterol ratio, and γ-glutamyltransferase.