Table 1.
Selected baseline characteristics and their cross-sectional associations with insulin-like growth factor (IGF)–I and IGF-binding protein (IGFBP)–3 levels.
| Variable | No. (%) | IGF-1 level, mean (95% CI), ng/mL | Final multivariate model of associations with IGF-I quartile | IGFBP-3 level, mean (95% CI), ng/mL | Final multivariate model of associations with IGFBP-3 quartile | ||
|---|---|---|---|---|---|---|---|
| OR (95% CI)a | Ptrendb | OR (95% CI)a | Ptrendb | ||||
| Age | <.001 | ||||||
| <26 years | 104 (7) | 295 (280 to 310) | 1.15 (0.92 to 1.39)*** | 3423 (3259 to 3588) | 0.39 (0.14 to 0.63)** | ||
| 26–29 years | 180 (13) | 265 (253 to 276) | 0.95 (0.75 to 1.15)*** | 3279 (3154 to 3404) | 0.45 (0.24 to 0.65)*** | ||
| 30–35 years | 405 (28) | 236 (228 to 243) | 0.71 (0.54 to 0.87)*** | 3226 (3143 to 3310) | 0.37 (0.19 to 0.55)*** | ||
| 36–45 years | 572 (40) | 200 (193 to 206) | 0.44 (0.28 to 0.60)*** | 2937 (2867 to 3007) | −0.39 (−0.56 to −0.22)*** | ||
| >45 years | 161 (11) | 178 (166 to 190) | Reference | 3084 (2953 to 3217) | Reference | ||
| Race/ethnicity | |||||||
| Black, non to Hispanic | 786 (55) | 226 (220 to 232) | 0.29 (0.16 to 0.42)*** | 3057 (2997 to 3118) | −0.45 (−0.61 to −0.29)*** | ||
| Hispanic | 351 (25) | 212 (204 to 309) | −0.03 (−0.18 to 0.12) | 3049 (2960 to 3140) | −0.39 (−0.56 to −0.21)*** | ||
| Other | 38 (3) | 221 (193 to 208) | −0.09 (−0.4 to 0.22) | 3163 (2889 to 3437) | −0.23 (−0.61 to 0.14) | ||
| White | 247 (17) | 227 (216 to 237) | Reference | 3384 (3276 to 3492) | Reference | ||
| CD4+ T cell count | .03 | .51 | |||||
| <200 cells/mm3 | 335 (24) | 216 (206 to 225) | −0.13 (−0.28 to 0.01) | 3230 (3137 to 3322) | 0.06 (−0.09 to 0.21) | ||
| 200–350 cells/mm3 | 346 (25) | 219 (209 to 228) | −0.07 (−0.21 to 0.06) | 3072 (2980 to 3164) | 0.01 (−0.13 to 0.14) | ||
| >350–500 cells/mm3 | 309 (22) | 227 (216 to 236) | 0.04 (−0.09 to 0.17) | 3099 (3002 to 3195) | 0.01 (−0.12 to 0.15) | ||
| >500 cells/mm3 | 406 (29) | 228 (220 to 237) | Reference | 3077 (2992 to 3161) | Reference | ||
| HIV RNA level | .22 | .005 | |||||
| >100,000 copies/mL | 277 (20) | 219 (209 to 229) | −0.20 (−0.35 to −0.05)*** | 3258 (3156 to 3360) | 0.22 (0.06 to 0.37)** | ||
| 20,001–100,000 copies/mL | 381 (27) | 221 (213 to 230) | −0.10 (−0.24 to 0.03) | 3145 (3058 to 3232) | 0.07 (−0.07 to 0.20) | ||
| >4000–20,000 copies/mL | 313 (22) | 214 (205 to 224) | −0.15 (−0.28 to −0.02)* | 2976 (2880 to 3072) | 0.001 (−0.14 to 0.14) | ||
| 0–4000 copies/mL | 446 (31) | 231 (223 to 239) | Reference | 3093 (3013 to 3173) | Reference | ||
| Prevalent clinical AIDS | |||||||
| AIDS at baseline | 412 (29) | 218 (210 to 226) | 3099 (3014 to 3183) | ||||
| No AIDS | 993 (71) | 224 (219 to 230) | 3126 (3072 to 3181) | ||||
| AZT use | |||||||
| Not currently using | 573 (40) | 222 (215 to 230) | 3080 (3008 to 3151) | ||||
| Currently using | 849 (60) | 223 (217 to 228) | 3139 (3081 to 3198) | ||||
| Body mass index | .007 | ||||||
| Underweight (<18.5 kg/m2) | 33 (2) | 268 (238 to 297) | 0.45 (0.13 to 0.76)** | 3557 (3261 to 3853) | |||
| Normal (18.5–25 kg/m2) | 561 (41) | 229 (222 to 236) | 0.41 (0.29 to 0.53)*** | 3094 (3022 to 3166) | |||
| Overweight (>25.0–30.0 kg/m2) | 423 (31) | 229 (221 to 237) | 0.43 (0.31 to 0.56)*** | 3138 (3056 to 3221) | |||
| Obese (>30.0 kg/m2) | 353 (26) | 202 (193 to 211) | Reference | 3078 (2988 to 3169) | |||
| Smoking | |||||||
| Not a current smoker | 635 (45) | 225 (219 to 232) | 3205 (3138 to 3273) | −0.09 (−0.2 to 0.02) | |||
| Current smoker | 787 (55) | 220 (214 to 226) | 3043 (2982 to 3103) | Reference | |||
| Injection drug use | |||||||
| Current | 133 (9) | 197 (182 to 211) | 2841 (2696 to 2987) | ||||
| Former | 432 (30) | 198 (190 to 206) | 2965 (2884 to 3046) | ||||
| No history of | 855 (60) | 239 (233 to 244) | 3232 (3175 to 3290) | ||||
| Alcohol consumption | |||||||
| Heavy (>13 drinks/week) | 125 (9) | 210 (195 to 226) | 2948 (2796 to 3101) | ||||
| Moderate (3–13 drinks/week) | 231 (17) | 219 (208 to 230) | 3173 (3061 to 3285) | ||||
| Light (<3 drinks/week) | 444 (32) | 231 (223 to 239) | 3160 (3080 to 3241) | ||||
| Abstains | 582 (42) | 220 (213 to 227) | 3088 (3018 to 3159) | ||||
| Hemoglobin level | |||||||
| ≤11 g/dL | 200 (14) | 225 (213 to 237) | 3245 (3125 to 3365) | ||||
| >11 g/dL | 1209 (86) | 222 (217 to 227) | 3091 (3042 to 3139) | ||||
| Hepatitis C virus status | |||||||
| Seropositive | 574 (41) | 196 (190 to 203) | −0.19 (−0.30 to −0.08)** | 2919 (2850 to 2988) | −0.18 (−0.30 to −0.06)** | ||
| Seronegative | 810 (59) | 242 (237 to 248) | Reference | 3266 (3208 to 3325) | Reference | ||
| ALT level | |||||||
| Elevated | 244 (17) | 188 (180 to 197) | 2880 (2791 to 2969) | ||||
| Not elevated | 1165 (83) | 234 (229 to 239) | 3196 (3144 to 3248) | ||||
| AST level | |||||||
| Elevated | 352 (25) | 198 (187 to 208) | 2936 (2830 to 3042) | ||||
| Not elevated | 1057 (75) | 228 (223 to 233) | 3156 (3106 to 3206) | ||||
| Albumin level | |||||||
| Low | 84 (6) | 198 (181 to 214) | 2849 (2685 to 3013) | ||||
| Not low | 1326 (94) | 225 (220 to 229) | 3139 (3091 to 3186) | ||||
| All liver tests (ALT, AST, albumin) | |||||||
| All results abnormal | 40 (3) | 153 (128 to 180) | 2448 (2182 to 2713) | ||||
| 1–2 results abnormal | 384 (27) | 198 (190 to 207) | 2961 (2876 to 3047) | ||||
| All results normal | 985 (70) | 235 (230 to 240) | 3204 (3150 to 3257) | ||||
| IGFBP-3 level | <.001 | ||||||
| First quartile | 348 (24) | 156 (148 to 163) | −1.64 (−1.79 to −1.50)*** | ||||
| Second quartile | 388 (27) | 203 (196 to 210) | −1.04 (−1.18 to −0.89)*** | ||||
| Third quartile | 329 (23) | 246 (238 to 253) | −0.54 (−0.69 to −0.40)*** | ||||
| Fourth quartile | 357 (25) | 287 (280 to 294) | Reference | ||||
| IGF-I level | <.001 | ||||||
| First quartile | 432 (30) | 2516 (2448 to 2585) | −1.58 (−1.72 to −1.44)*** | ||||
| Second quartile | 329 (23) | 2978 (2899 to 3056) | −1.02 (−1.15 to −0.89)*** | ||||
| Third quartile | 316 (22) | 3349 (3269 to 3429) | −0.44 (−0.58 to −0.30)*** | ||||
| Fourth quartile | 345 (24) | 3782 (3705 to 3858) | Reference | ||||
NOTE. Percentages do not always total to 100% because of rounding. The total no. of subjects does not always equal 1422 because of the unavailability of the indicated data. Serocutoffs for IGF-I and IGFBP-3 were defined using the quartile values obtained in a random subsample of HIV-uninfected women enrolled in the Women’s Interagency HIV Study. For IGF-I, these serocutoffs were 173, 219, and 275 ng/mL. For IGFBP-3, these serocutoffs were 2497, 3094, and 3660 ng/mL. The univariate analyses show results based on the absolute (continuous) values for IGF-I and IGFBP-3 (to demonstrate scale). However, the multivariate analysis is based on the quartile of IGF-I and IGFBP-3 level, consistent with the use of these quartiles in studying the associations of IGF-I and IGFBP-3 with the risk of incident AIDS. Thus, the effect estimates in the multivariate models indicate the strength of the association but do not relate to the SD of IGF-I or IGFBP-3 level (as would be the case if their continuous values were used in the analysis). ALT, alanine transaminase; AST, aspartate transaminase; AZT, azidothymidine; CI, confidence interval; OR, odds ratio.
*P < .05; **P < .01; ***P < .001.
Ptrend is reported only for ordinal data and only if statistically significant (i.e., <.05).