Table 2.

Associations of annual average PM2.5 with baseline eGFR and urinary albumin-creatinine ratio

CharacteristicNumber of Eligible ParticipantseGFRUACRa
ml/min per 1.73 m2 (95% CI)P ValueInteraction P Value% Difference (95% CI)P ValueInteraction P Value
Overall
 Model 1b10,9970.14 (−0.32 to 0.60)0.558.5 (3.6 to 13.7)<0.001
 Model 2c0.07 (−0.28 to 0.41)0.716.6 (2.6 to 10.7)0.001
Sex
 Male48360.16 (−0.25 to 0.56)0.460.5610.3 (5.9 to 14.9)<0.0010.09
 Female6161−0.00 (−0.52 to 0.52)1.003.7 (−1.7 to 9.4)0.18
Age, yr
 <6565970.03 (−0.40 to 0.46)0.900.957.0 (0.8 to 13.7)0.030.32
 ≥6544000.17 (−0.26 to 0.60)0.445.9 (1.7 to 10.3)0.005
History of diabetes
 No91350.06 (−0.36 to 0.48)0.780.676.0 (2.8 to 9.4)<0.0010.44
 Yes18150.46 (−0.43 to 1.35)0.317.6 (−8.6 to 26.7)0.38
History of hypertension
 No5729−0.05 (−0.49 to 0.39)0.810.617.5 (1.0 to 14.4)0.020.75
 Yes52240.24 (−0.21 to 0.70)0.295.2 (−0.3 to 11.1)0.07
Income above mediand
 No60430.09 (−0.28 to 0.47)0.640.906.5 (1.4 to 11.8)0.010.80
 Yes44590.03 (−0.55 to 0.60)0.937.5 (3.5 to 11.8)<0.001
  • PM2.5, particulate matter <2.5 μm in aerodynamic diameter; UACR, urinary albumin-creatinine ratio.

  • a UACR coefficient underwent exponentiation using the formula (eβ−1)×100%.

  • b Model 1: sex, age, race, neighborhood socioeconomic score, family income, education level.

  • c Model 2: model 1 plus body mass index, diabetes mellitus, hypertension, systolic BP, composite cardiovascular disease, cigarette smoking, eGFR,* UACR,** C-reactive protein, temperature. Covariate omitted for eGFR analyses (*) and UACR analyses (**). Model 2 adjustment used for stratified analyses. Analyses performed per 1-μg/m3 higher PM2.5.

  • d Median income was $16,000–$24,999 for Jackson, $25,000–$34,999 for Washington County, and $35,000–$49,999 for Forsyth County and Minneapolis.