Table 3.
Predicted geometric mean (95% confidence interval, 95% CI) of weight, waist circumference and body fat mass, as well as predicted mean (95% CI) of proportion fat mass by tertile of n-PFOAserum concentrations; and ratios of geometric mean or difference in mean across the comparison groups in women with the second the third tertiles vs. the lowest tertile as reference, from linear mixed-effect models.
| Weight | |||||
|---|---|---|---|---|---|
| Geometric mean (95% CI), kg | Ratio of geometric mean (95% CI)b | ||||
| Tertile of n-PFOA concentrationsc | |||||
| Tertile 1 | Tertile 2 | Tertile 3 | Tertile 2 vs. 1 | Tertile 3 vs. 1 | |
| Baseline | 69.4 (67.6, 71.2) | 72.8 (71.1, 74.6) | 74.0 (72.3, 75.8) | 1.05 (1.02, 1.08) | 1.07 (1.03, 1.10) |
| Year 5 | 69.9 (68.1, 71.7) | 73.4 (71.6, 75.1) | 74.8 (73.0, 76.5) | 1.05 (1.02, 1.08) | 1.07 (1.04, 1.10) |
| Year 10 | 70.1 (68.3, 71.9) | 73.5 (71.8, 75.3) | 75.2 (73.5, 77.0) | 1.05 (1.02, 1.08) | 1.07 (1.04, 1.11) |
| Year 15 | 69.5 (67.7, 71.3) | 72.3 (70.6, 74.1) | 74.3 (72.6, 76.1) | 1.04 (1.01, 1.07) | 1.07 (1.04, 1.10) |
| Waist circumference | |||||
| Geometric mean (95% CI), cm | Ratio of geometric mean (95% CI)b | ||||
| Tertile of n-PFOA concentrationsc | |||||
| Tertile 1 | Tertile 2 | Tertile 3 | Tertile 2 vs. 1 | Tertile 3 vs. 1 | |
| Baseline | 83.9 (82.3, 85.4) | 85.7 (84.2, 87.2) | 87.6 (86.1, 89.1) | 1.02 (1.00, 1.04) | 1.04 (1.02, 1.07) |
| Year 5 | 85.3 (83.8, 86.9) | 87.3 (85.8, 88.8) | 89.3 (87.8, 90.8) | 1.02 (1.00, 1.04) | 1.05 (1.02, 1.07) |
| Year 10 | 86.7 (85.1, 88.3) | 88.7 (87.2, 90.3) | 90.7 (89.2, 92.3) | 1.02 (1.00, 1.04) | 1.04 (1.02, 1.07) |
| Year 15 | 87.8 (86.2, 89.4) | 89.3 (87.7, 90.8) | 91.1 (89.6, 92.7) | 1.02 (1.00, 1.04) | 1.04 (1.02, 1.06) |
| Body fat mass | |||||
| Geometric mean (95% CI), kg | Ratio of geometric mean (95% CI)b | ||||
| Tertile of n-PFOA concentrationsc | |||||
| Tertile 1 | Tertile 2 | Tertile 3 | Tertile 2 vs. 1 | Tertile 3 vs. 1 | |
| Baseline | 25.1 (24.0, 26.2) | 27.0 (25.9, 28.1) | 28.0 (26.9, 29.1) | 1.08 (1.03, 1.13) | 1.12 (1.06, 1.17) |
| Year 5 | 25.3 (24.3, 26.4) | 27.2 (26.1, 28.3) | 28.2 (27.1, 29.3) | 1.07 (1.02, 1.12) | 1.11 (1.06, 1.17) |
| Year 10 | 25.6 (24.5, 26.7) | 27.3 (26.2, 28.4) | 28.4 (27.3, 29.5) | 1.07 (1.02, 1.12) | 1.11 (1.06, 1.16) |
| Year 15 | 25.7 (24.6, 26.9) | 27.3 (26.2, 28.4) | 28.5 (27.4, 29.7) | 1.06 (1.01, 1.11) | 1.11 (1.05, 1.16) |
| Proportion fat mass | |||||
| Mean (95% CI), % | Difference in mean (95% CI), % | ||||
| Tertile of n-PFOA concentrationsc | |||||
| Tertile 1 | Tertile 2 | Tertile 3 | Tertile 2 vs. 1 | Tertile 3 vs. 1 | |
| Baseline | 40.6 (39.8, 41.3) | 41.6 (40.8, 42.3) | 42.5 (41.8, 43.2) | 0.99 (0.17, 1.80) | 1.91 (1.07, 2.75) |
| Year 5 | 40.9 (40.2, 41.6) | 41.8 (41.1, 42.5) | 42.7 (42.0, 43.4) | 0.94 (0.15, 1.74) | 1.81 (0.99, 2.64) |
| Year 10 | 41.2 (40.5, 42.0) | 42.1 (41.4, 42.8) | 42.9 (42.2, 43.6) | 0.90 (0.09, 1.71) | 1.71 (0.87, 2.55) |
| Year 15 | 41.4 (40.7, 42.2) | 42.2 (41.5, 43.0) | 43.1 (42.4, 43.8) | 0.84 (0.008, 1.67) | 1.67 (0.82, 2.53) |
Models were adjusted for age at baseline, race, study site, education, financial strain, smoking status, passive smoking, alcohol consumption, total calorie intake, physical activity, and menopausal status.
Weight, waist circumference, and body fat mass were log-transformed to ensure normality; thus ratios of geometric mean (95% CI) were calculated.
Medians (ranges) of n-PFOA concentrations by tertiles were 2.4 (<LOD, 3.2) ng/mL for tertile 1, 4.1 (3.3, 5.1) ng/mL for tertile 2, and 6.8 (5.2, 56.5) ng/mL for tertile 3.