Table 2. Adjusted Association of Each Phthalate Metabolite With High TT Levels and Low SHBG Levels.
| Metabolite | High TT level | Low SHBG level | ||||
|---|---|---|---|---|---|---|
| RR (95% CI)a | P value, overall | P value | RR (95% CI)a | P value, overall | P value | |
| MCNP | ||||||
| T1 | 1 [Reference] | .44 | NA | 1 [Reference] | .05 | NA |
| T2 | 0.80 (0.53-1.20) | .26 | 1.35 (0.84-2.16) | .21 | ||
| T3 | 0.82 (0.56-1.18) | .27 | 1.81 (1.15-2.87) | .01b | ||
| MCOP | ||||||
| T1 | 1 [Reference] | .66 | NA | 1 [Reference] | .02 | NA |
| T2 | 0.80 (0.47-1.35) | .39 | 1.79 (1.19-2.71) | .007b | ||
| T3 | 0.80 (0.48-1.34) | .39 | 1.96 (1.21-3.16) | .008b | ||
| MECPP | ||||||
| T1 | 1 [Reference] | .68 | NA | 1 [Reference] | .003b | NA |
| T2 | 0.85 (0.55-1.30) | .44 | 1.43 (0.94-2.16) | .09 | ||
| T3 | 1.02 (0.72-1.45) | .91 | 1.84 (1.33-2.54) | .001b | ||
| MBP | ||||||
| T1 | 1 [Reference] | .08 | NA | 1 [Reference] | .04 | NA |
| T2 | 0.77 (0.53-1.12) | .17 | 1.75 (1.05-2.93) | .03 | ||
| T3 | 1.09 (0.74-1.62) | .64 | 1.70 (1.10-2.62) | .02 | ||
| MCPP | ||||||
| T1 | 1 [Reference] | .20 | NA | 1 [Reference] | .03 | NA |
| T2 | 0.73 (0.49-1.10) | .12 | 1.62 (1.09-2.41) | .02 | ||
| T3 | 0.72 (0.48-1.07) | .10 | 1.55 (1.04-2.30) | .03 | ||
| MEP | ||||||
| T1 | 1 [Reference] | .69 | NA | 1 [Reference] | <.001b | NA |
| T2 | 1.17 (0.66-2.09) | .57 | 2.42 (1.65-3.55) | <.001b | ||
| T3 | 1.24 (0.75-2.03) | .39 | 2.31 (1.47-3.63) | .001b | ||
| MEHHP | ||||||
| T1 | 1 [Reference] | .26 | NA | 1 [Reference] | .003b | NA |
| T2 | 0.71 (0.46-1.08) | .11 | 1.45 (0.92-2.29) | .10 | ||
| T3 | 0.96 (0.64-1.44) | .84 | 1.94 (1.34-2.81) | .001b | ||
| MEHP | ||||||
| T1 | 1 [Reference] | .44 | NA | 1 [Reference] | .45 | NA |
| T2 | 1.20 (0.88-1.64) | .24 | 1.11 (0.75-1.64) | .60 | ||
| T3 | 1.01 (0.71-1.43) | .95 | 1.23 (0.86-1.77) | .24 | ||
| MiBP | ||||||
| T1 | 1 [Reference] | .60 | NA | 1 [Reference] | .02 | NA |
| T2 | 0.78 (0.48-1.28) | .31 | 1.78 (1.09-2.91) | .02 | ||
| T3 | 0.88 (0.61-1.25) | .45 | 1.71 (1.15-2.54) | .01b | ||
| MNP | ||||||
| T1/T2 | 1 [Reference] | .54 | NA | 1 [Reference] | .42 | NA |
| T3 | 0.89 (0.61-1.30) | .54 | 1.12 (0.85-1.48) | .42 | ||
| MEOHP | ||||||
| T1 | 1 [Reference] | .31 | NA | 1 [Reference] | .02 | NA |
| T2 | 0.76 (0.49-1.17) | .20 | 1.57 (1.02-2.43) | .04 | ||
| T3 | 1.05 (0.72-1.55) | .78 | 1.77 (1.21-2.59) | .005b | ||
| MBzP | ||||||
| T1 | 1 [Reference] | .82 | NA | 1 [Reference] | .02 | NA |
| T2 | 0.87 (0.55-1.37) | .53 | 1.44 (0.90-2.29) | .13 | ||
| T3 | 0.94 (0.64-1.37) | .72 | 1.75 (1.21-2.54) | .004b | ||
| MHNCH | ||||||
| T1 | 1 [Reference] | .51 | NA | 1 [Reference] | .57 | NA |
| T2 | 1.41 (0.78-2.54) | .25 | 0.86 (0.51-1.48) | .58 | ||
| T3 | 0.98 (0.72-1.34) | .89 | 1.18 (0.84-1.67) | .34 | ||
Abbreviations: MBP, mono-n-butyl phthalate (ng/mL); MBzP, monobenzyl phthalate (ng/mL); MCNP, monocarboxynonyl phthalate (ng/mL); MCOP, monocarboxyoctyl phthalate (ng/mL); MCPP, mono(3-carboxypropyl) phthalate; MECPP, mono(2-ethyl-5-carboxypenty) phthalate; MEHHP, mono(2-ethyl-5-hydroxyhexyl) phthalate; MEHP, mono(2-ethylhexyl) phthalate (ng/mL); MEOHP, mono(2-ethyl-5-oxohexyl) phthalate; MEP, monoethyl phthalate (ng/mL); MHNCH, cyclohexane-1,2-dicarboxylic acid-mono(hydroxy isononyl) ester (ng/mL); MiBP, mono-isobutyl phthalate; MNP, monoisononyl phthalate (ng/mL); NA, not applicable; RR, relative risk; SHBG, sex hormone–binding globulin; T1, first tertile (reference category); T2, second tertile; T3, third tertile; TT, total testosterone.
All analyses adjusted for age, race and ethnicity, income, marital status, birth country, educational level, smoking status, alcohol use status, physical activity, and creatinine level.
P values are significant at a 1% level of significance after adjusting for multiple comparisons. The overall P value provides an overall association between each phthalate metabolite and each outcome, whereas the P value provides the association of each level of phthalate metabolite with each outcome.