Table 3.
Associations of the interquartile rangea, b in steps/day, MVPA, LPA, sitting time, and mean sitting bout duration with incident probable dementia among older women in the Objective Physical Activity and Cardiovascular Health (OPACH) Study 2012–2020, stratified by baseline characteristics.
| Steps (n/day) | MVPA (minutes/day) | LPA (minutes/day) | Sitting time (minutes/day) | MSBD (minutes) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | n events | HR (95% CI) | P-interaction | HR (95% CI) | P-interaction | HR (95% CI) | P-interaction | n* | n events* | HR (95% CI) | P-interaction | HR (95% CI) | P-interaction | |
| Overall association | 1,082 | 143 | 0.67 (0.50–0.90) | 0.83 (0.63–1.09) | 0.96 (0.73–1.24) | 1,041 | 134 | 0.92 (0.71–1.19) | 1.04 (0.84–1.28) | |||||
| Age | 0.689 | 0.492 | 0.605 | 0.992 | 0.25 | |||||||||
| <83 | 494 | 38 | 0.99 (0.59–1.67) | 0.92 (0.56–1.52) | 1.00 (0.58–1.71) | 478 | 37 | 0.70 (0.42–1.16) | 1.23 (0.81–1.86) | |||||
| ≥83 | 588 | 105 | 0.52 (0.35–0.77) | 0.79 (0.56–1.12) | 0.89 (0.65–1.22) | 563 | 97 | 1.04 (0.75–1.42) | 1.01 (0.79–1.30) | |||||
| BMI | 0.668 | 0.396 | 0.756 | 0.548 | 0.595 | |||||||||
| < 30 kg/m2 | 769 | 115 | 0.65 (0.47–0.89) | 0.77 (0.57–1.05) | 1.02 (0.76–1.38) | 742 | 108 | 0.91 (0.68–1.22) | 1.06 (0.82–1.37) | |||||
| ≥ 30 kg/m2 | 313 | 28 | 0.55 (0.18–1.71) | 1.02 (0.42–2.44) | 0.63 (0.29–1.34) | 299 | 26 | 1.24 (0.50–3.07) | 0.99 (0.60–1.61) | |||||
| RAND-36 physical functioning | 0.016 | 0.314 | 0.567 | 0.243 | 0.723 | |||||||||
| < 75 | 564 | 75 | 0.47 (0.28–0.80) | 0.69 (0.44–1.07) | 0.89 (0.60–1.31) | 545 | 70 | 1.07 (0.72–1.59) | 0.99 (0.77–1.27) | |||||
| ≥ 75 | 518 | 68 | 0.72 (0.49–1.05) | 0.94 (0.65–1.34) | 1.04 (0.72–1.50) | 496 | 64 | 0.80 (0.56–1.16) | 0.94 (0.62–1.45) | |||||
| Reynolds risk score | 0.395 | 0.049 | 0.256 | 0.705 | 0.316 | |||||||||
| < 12.2 | 507 | 55 | 0.58 (0.35–0.95) | 0.72 (0.46–1.11) | 0.87 (0.55–1.38) | 495 | 50 | 0.94 (0.61–1.45) | 1.10 (0.68–1.78) | |||||
| ≥ 12.2 | 575 | 88 | 0.69 (0.45–1.05) | 0.88 (0.58–1.34) | 0.98 (0.68–1.39) | 546 | 84 | 0.94 (0.66–1.34) | 1.03 (0.79–1.33) | |||||
| APOE ε4 carrier status | 0.887 | 0.462 | 0.917 | 0.889 | 0.585 | |||||||||
| 0 | 844 | 107 | 0.70 (0.50–0.99) | 0.81 (0.59–1.12) | 1.00 (0.74–1.34) | 814 | 101 | 0.89 (0.65–1.20) | 1.04 (0.82–1.31) | |||||
| 1 or 2 | 238 | 36 | 0.64 (0.34–1.19) | 0.93 (0.53–1.61) | 0.80 (0.44–1.46) | 227 | 33 | 0.97 (0.53–1.78) | 1.01 (0.59–1.70) | |||||
HR=hazard ratio; CI=confidence interval; MVPA=moderate-to-vigorous intensity physical activity; LPA=light intensity physical activity; BMI=body mass index; SPPB=Short Physical Performance Battery; APOE=apolipoprotein E; MSBD=mean sitting bout duration
Accelerometer measures were modeled as continuous variables
Interquartile ranges: steps/day=2,163; MVPA=38 minutes/day; LPA=96 minutes/day; sitting time=134 minutes/day; MSBD=6.1 minutes/day
Models adjusted for age, race and ethnicity, educational attainment, alcohol use, smoking, diabetes, hypertension, RAND-36 physical functioning, BMI, and APOE ε4 carrier status. Model results were estimated with missing covariate data for women with APOE ε4 data imputed using multiple imputation by chained equations (MICE) from the R mice package.
n and n events for models with sitting time and MSBD