Table 4.
Four-Combination Effects of Baseline Loneliness and Isolated Living status on Stress-related Biomarkers, Depressive Symptoms, and Disability 6 Years Later
| Cortisol | IL-6 | hsCRP | |||||||
| B(95%CI) | R2 | p | B(95%CI) | R2 | p | B(95%CI) | R2 | p | |
| Model 1: Unconditional | 0.03 | 0.004 | 0.02 | 0.02 | 0.04 | <0.001 | |||
| Lonely and Isolated | -1.79 (-7.79 to 4.21) | 1.47 (-0.52 to 3.46) | -0.003 (-0.21 to 0.21) | ||||||
| Not Lonely, but Isolated | -2.70 (-6.85 to 1.45) | 0.24 (-1.19 to 1.67) | 0.04 (-0.12 to 0.19) | ||||||
| Lonely, but Not Isolated | 9.11 (3.47 to 14.75) | 2.96 (1.02 to 4.91) | 0.50 (0.30 to 0.71) | ||||||
| Model 2: Baseline adjusted | 0.04 | <0.001 | 0.11 | <0.001 | - | - | |||
| Lonely and Isolated | -0.60 (-6.62 to 5.42) | 0.99 (-0.92 to 2.91) | - | ||||||
| Not Lonely, but Isolated | -2.01 (-6.17 to 2.14) | 0.25 (-1.14 to 1.64) | - | ||||||
| Lonely, but Not Isolated | 9.34 (3.73 to 14.95) | 3.20 (1.31 to 5.09) | - | ||||||
| Model 3: Full adjusted | 0.08 | <0.001 | 0.13 | <0.001 | 0.07 | <0.001 | |||
| Lonely and Isolated | 0.41 (-6.06 to 6.89) | 0.42 (-1.68 to 1.63) | -0.09 (-0.32 to 0.14) | ||||||
| Not Lonely, but Isolated | -1.60 (-5.94 to 2.74) | -0.06 (-1.53 to 1.41) | 0.05 (-0.11 to 0.21) | ||||||
| Lonely, but Not Isolated | 9.25 (3.24 to 15.27) | 2.76 (0.72 to 4.79) | 0.40 (0.17 to 0.62) | ||||||
| #CES-D score | Mobility | IADL | |||||||
| B(95%CI) | R2 | p | B(95%CI) | R2 | p | B(95%CI) | R2 | p | |
| Model 1: Unconditional | 0.05 | <0.001 | 0.04 | <0.001 | 0.03 | <0.001 | |||
| Lonely and Isolated | 4.15 (2.54 to 5.77) | 4.07 (2.15 to 5.98) | 1.92 (0.78 to 3.06) | ||||||
| Not Lonely, but Isolated | 1.14 (0.03 to 2.25) | 2.38 (1.07 to 3.70) | 1.35 (0.57 to 2.13) | ||||||
| Lonely, but Not Isolated | 2.31 (0.80 to 3.82) | 2.02 (0.23 to 3.81) | 0.95 (-0.11 to 2.02) | ||||||
| Model 2: Baseline adjusted | 0.13 | <0.001 | 0.36 | <0.001 | 0.29 | <0.001 | |||
| Lonely and Isolated | 2.34 (0.72 to 3.97) | 1.18 (-0.43 to 2.79) | 0.90 (-0.09 to 1.89) | ||||||
| Not Lonely, but Isolated | 0.97 (-0.10 to 2.03) | 0.86 (-0.24 to 1.95) | 0.74 (0.06 to 1.41) | ||||||
| Lonely, but Not Isolated | 0.07 (-1.49 to 1.64) | -0.90 (-2.41 to 0.60) | -0.25 (-1.18 to 0.68) | ||||||
| Model 3: Full adjusted | 0.22 | <0.001 | 0.41 | <0.001 | 0.35 | <0.001 | |||
| Lonely and Isolated | 1.70 (0.11 to 3.30) | 0.19 (-1.41 to 1.79) | 0.29 (-0.65 to 1.22) | ||||||
| Not Lonely, but Isolated | 0.48 (-0.62 to 1.58) | -0.35 (-1.45 to 0.75) | 0.10 (-0.54 to 0.75) | ||||||
| Lonely, but Not Isolated | -0.61 (-2.15 to 0.92) | -1.15 (-2.70 to 0.39) | -0.29 (-1.19 to 0.61) | ||||||
Note. The “Neither Lonely, nor Isolated” group was the reference group. 2. CES-D The Center for Epidemiologic Studies Depression Scale; IADL Instrumental Activities of Daily Living; IL-6 Interleukin-6; hsCRP High sensitivity C-reactive protein. #9-item CES-D score (excluding lonely). 3. Bold numbers indicate significance (p < 0.05)