Table 1.
Associations of Abnormal Levels of Physiological Measures With Frailty and Prefrailty: Women Aged 70–79 Years in the Women’s Health and Aging Studies. (A) Means and Frequencies of System Deficits and (B) Multivariate Analysis: Associations of Individual Systems at Abnormal Levels With the Risk of Being Frail (vs Nonfrail; N = 704)*
| A |
B |
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| % Abnormal |
Frail vs Nonfrail |
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| System | Measure‡ | Overall (N = 704) | Nonfrail (N = 284) | Prefrail (N = 330) | Frail (N = 90) | p Value† | Odds Ratio (95% CI) |
| Anemia | Hemoglobin in g/dL, M (SD) | 13.1 (1.1) | 13.2 (1.1) | 13.2 (1.1) | 12.6 (1.1) | <.01 | 1.5 (0.7–3.4) |
| Hemoglobin <12 g/dL (%) | 13.3 | 10.1 | 13.3 | 27.0 | <.01 | ||
| Inflammation | IL-6 in pg/mL, M (SD) | 3.4 (2.0) | 3.0 (1.69) | 3.7 (2.09) | 4.7 (2.20) | <.01 | 1.2 (0.6–2.2) |
| IL-6 >4.6 pg/mL (%) | 25.3 | 19.3 | 28.3 | 38.6 | <.01 | ||
| Endocrine | IGF-1 in ng/mL, M (SD) | 111.8 (1.6) | 114.0 (1.5) | 113.2 (1.6) | 98.3 (1.6) | .04 | 1.7 (0.8–3.4) |
| IGF-1 <74.3 ng/mL (%) | 17.4 | 13.8 | 18.6 | 27.0 | .03 | ||
| DHEA-S in mcg/mL, M (SD) | 0.38 (2.18) | 0.42 (2.14) | 0.36 (2.17) | 0.31 (2.24) | <.01 | 1.4 (0.7–2.8) | |
| DHEA-S <0.215 mcg/mL (%) | 24.3 | 21.3 | 25.4 | 33.7 | .10 | ||
| Hemoglobin A1c, M (SD) | 6.1 (1.2) | 5.9 (1.1) | 6.2 (1.2) | 6.1 (1.2) | <.01 | 1.2 (0.5–2.4) | |
| Hemoglobin A1c ≥6.5 (%) | 23.5 | 16.3 | 29.3 | 29.9 | <.01 | ||
| Micronutrients | 25-Hydroxyvitamin vitamin D in nmol/L, M (SD) | 20.1 (1.6) | 20.8 (1.6) | 20.0 (1.6) | 17.6 (1.8) | .08 | 2.6 (1.3–5.0)‖ |
| Folate in ng/mL, M (SD) | 9.7 (1.8) | 10.0 (1.8) | 9.5 (1.8) | 9.6 (1.9) | .64 | ||
| Vitamin B12 in pg/mL, M (SD) | 439.9 (1.7) | 444.2 (1.6) | 440.1 (1.7) | 420.0 (1.7) | .68 | ||
| Alpha-tocopherol in μmol/L, M (SD) | 21.8 (1.5) | 22.6 (1.5) | 21.6 (1.5) | 19.7 (1.4) | .01 | ||
| Total carotenoids in μmol/L, M (SD) | 1.7 (1.6) | 1.9 (1.6) | 1.6 (1.7) | 1.4 (1.6) | <.01 | ||
| ≥2 nutritional deficits§ (%) | 22.6 | 17.9 | 24.1 | 35.4 | <.01 | ||
| Adiposity | Skinfold thickness in mm, M (SD) | 23.0 (8.3) | 23.1 (7.3) | 23.5 (8.7) | 20.4 (9.7) | .03 | 2.6 (1.3–5.2)‖ |
| Skinfold thickness <17 mm (%) | 24.8 | 19.8 | 25.9 | 40.1 | <.01 | ||
| Fine motor speed | Purdue Pegboard in s, M (SD) | 28.6 (1.2) | 27.3 (1.2) | 29.0 (1.2) | 33.5 (1.3) | <.01 | 3.4 (1.8–6.5)‖ |
| Purdue Pegboard >31.9 s (%) | 24.0 | 14.5 | 26.5 | 51.5 | <.01 | ||
Notes: CI = confidence interval. Nonfrail, zero criterion; prefrail, one to two criteria; and frail, three or more criteria present.
Multivariable adjusted polytomous regression analysis, including all systems indicated and adjusted for age, race, education, and number of chronic diseases. Analyses were restricted to the subset of women with complete data on all eight systems for valid comparison between univariate and multivariate associations. In the multivariate analysis, all the systems were entered into a model simultaneously to assess the independent association of each system with frailty and prefrailty after adjusting for the other systems.
Based on analysis of variance test for continuous variables and chi-square test for categorical variables.
Geometric mean and geometric standard deviation for all continuous measures except for skinfold thickness, where arithmetic mean and standard deviation are used instead.
Cutoffs for defining deficits: 25-hydroxyvitamin vitamin D <30 nmol/L, folate < 5 ng/mL, vitamin B12 <300 pg/mL, alpha-tocopherol <11.6 μmol/L, and total carotenoids <0.45 μmol/L.
p value <.05.