Table 2.
Effect of Diet, Exercise, or Both on Primary and Secondary Outcome Variables in Obese Older Adults.✲
| Outcome Variable | Control (N = 27) | Diet (N = 26) | Exercise (N = 26) | Diet–Exercise (N = 28) | P Value† | ||||
|---|---|---|---|---|---|---|---|---|---|
| Interaction between Group and Time | Diet vs. Control | Exercise vs. Control | Diet–Exercise vs. Diet | Diet–Exercise vs. Exercise | |||||
| Primary outcome | |||||||||
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| PPT score† | |||||||||
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| Baseline | 26.8±4.5 | 28.6±1.9 | 27.1±3.1 | 28.0±2.9 | |||||
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| Change at 6 mo | 0.6±1.7 | 2.3±1.8‡ | 3.4±2.4‡ | 4.7±2.4‡ | |||||
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| Change at 1 yr | 0.2±1.8 | 3.1±1.4‡ | 4.0±2.5‡ | 5.4±2.4‡ | <0.001 | <0.001 | <0.001 | <0.001 | 0.04 |
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| Secondary outcomes | |||||||||
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| Other frailty measures | |||||||||
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| VO2peak (ml/kg/min) | |||||||||
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| Baseline | 16.3±3.8 | 17.6±2.2 | 17.4±3.5 | 17.3±3.5 | |||||
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| Change at 6 mo | −0.7±2.3 | 1.4±1.7‡ | 1.3±1.0‡ | 2.8±2.3‡ | |||||
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| Change at 1 yr | −0.9±1.5 | 1.7±2.3‡ | 1.4±1.0‡ | 3.1±2.4‡ | <0.001 | <0.001 | <0.001 | 0.01 | 0.002 |
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| FSQ score | |||||||||
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| Baseline | 30.5±3.2 | 31.6±2.0 | 29.8±3.3 | 30.0±3.5 | |||||
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| Change at 6 mo | −0.1±3.1 | 0.9±1.5‡ | 1.9±2.9‡ | 2.4±2.3‡ | |||||
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| Change at 1 yr | −0.2±2.4 | 1.3±1.5‡ | 1.8±2.7§ | 2.7±2.6‡ | <0.001 | 0.05 | 0.005 | 0.04 | 0.19 |
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| Body weight and composition | |||||||||
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| Weight (kg) | |||||||||
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| Baseline | 101.0±16.3 | 104.1±15.3 | 99.2±17.4 | 99.1±16.8 | |||||
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| Change at 6 mo | 0.9±2.8 | −9.0±5.4‡ | −0.3±2.3 | −7.7±4.2‡ | |||||
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| Change at 1 yr | −0.1±3.5 | −9.7±5.4‡ | −0.5±3.6 | −8.6±3.8‡ | <0.001 | <0.001 | 0.71 | 0.67 | <0.001 |
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| Lean body mass (kg) | |||||||||
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| Baseline | 57.3±11.5 | 61.4±13.0 | 57.6±13.7 | 57.2±10.3 | |||||
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| Change at 6 mo | −0.7±2.3 | −3.5±2.7‡ | 1.1±2.1¶ | −1.7±1.6‡ | |||||
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| Change at 1 yr | −0.8±2.5 | −3.2±2.0‡ | 1.3±1.6¶ | −1.8±1.7‡ | <0.001 | <0.001 | <0.001 | 0.04 | <0.001 |
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| Fat mass (kg) | |||||||||
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| Baseline | 43.8±9.9 | 42.8±6.6 | 41.6±9.4 | 41.9±11.5 | |||||
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| Change at 6 mo | −0.3±3.4 | −6.0±3.8‡ | −1.2±2.0 | −5.6±3.2‡ | |||||
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| Change at 1 yr | 1.2±5.1 | −7.1±3.9‡ | −1.8±1.9 | −6.3±2.8‡ | <0.001 | <0.001 | 0.004 | 0.57 | <0.001 |
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| Thigh muscle (cm3) | |||||||||
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| Baseline | 1138±290 | 1271±280 | 1188±234 | 1261±253 | |||||
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| Change at 1 yr | −7±54 | −81±63‡ | 30±34‡ | −28±63¶ | <0.001 | <0.001 | 0.045 | <0.001 | <0.001 |
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| Thigh fat (cm3) | |||||||||
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| Baseline | 1813±773 | 1553±529 | 1423±541 | 1472±718 | |||||
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| Change at 1 yr | −0.5±158 | −255±179‡ | −76±97§ | −247±217‡ | <0.001 | <0.001 | 0.19 | 0.44 | 0.02 |
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| Bone mineral density at total hip (g/cm2) | |||||||||
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| Baseline | 0.962±0.132 | 1.021±0.139 | 0.958±0.151 | 1.014±0.151 | |||||
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| Change at 6 mo | −0.003±0.016 | −0.015±0.017¶ | 0.008±0.012‡ | −0.010±0.024¶ | |||||
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| Change at 1 yr | −0.007±0.019¶ | −0.027±0.021¶ | 0.013±0.014‡ | −0.011±0.026¶ | <0.001 | 0.001 | 0.001 | 0.005 | <0.001 |
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| Strength, balance, and gait | |||||||||
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| Total 1RM (lb)∣ | |||||||||
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| Baseline | 505±143 | 607±213 | 519±187 | 539±218 | |||||
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| Change at 6 mo | −16±78 | 8±60 | 110±138§ | 96±108§ | |||||
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| Change at 1 yr | −6±101 | 1±85 | 174±166‡ | 164±124‡ | <0.001 | 0.90 | <0.001 | <0.001 | 0.32 |
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| Obstacle course (sec) | |||||||||
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| Baseline | 11.6±3.3 | 11.0±2.2 | 10.9±3.3 | 10.7±3.3 | |||||
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| Change at 6 mo | −0.1±1.2 | −0.7±1.3 | −1.6 ±1.6‡ | −1.1±2.2 | |||||
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| Change at 1 yr | 0.0±1.0 | −1.1±1.1 | −1.5±1.4‡ | −1.7±2.2‡ | 0.002 | 0.03 | 0.004 | 0.18 | 0.68 |
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| One-leg stance (sec) | |||||||||
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| Baseline | 10.7±10.6 | 11.7±8.7 | 13.4±10.4 | 10.5±9.5 | |||||
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| Change at 6 mo | −2.4±8.2 | 0.8±6.1 | 1.4±7.7 | 6.3±7.6‡ | |||||
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| Change at 1 yr | −2.3±9.4 | 4.7±5.0‡ | 3.4±5.9¶ | 7.9±7.8‡ | <0.001 | 0.001 | 0.02 | 0.18 | 0.04 |
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| Gait speed (m/min) | |||||||||
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| Baseline | 75.5±17.6 | 87.5±15.8 | 76.0±18.3 | 72.9±14.9 | |||||
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| Change at 6 mo | −3.0±10.5 | 1.7±5.4 | 7.6±14.8§ | 5.5±7.6§ | |||||
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| |||||||||
| Change at 1 yr | 1.1±11.0 | 4.7±5.2 | 8.2±15.5§ | 16.9±42.3§ | 0.02 | 0.45 | 0.003 | 0.04 | 0.39 |
Plus–minus values are means ±SD. Scores on the modified Physical Performance Test (PPT, the primary outcome) range from 0 to 36, with higher scores indicating better physical function. Peak oxygen consumption (VO2peak) was assessed during graded treadmill walking. Scores on the Functional Status Questionnaire (FSQ) range from 0 to 36, with higher scores indicating better functional status.
P values for the comparison among the groups of changes from baseline to 1 year were calculated with the use of mixed-model repeated-measures analysis of variance (with baseline values and sex as covariates) and are reported when the overall P value was less than 0.05 for the interaction among the four groups over time. Bonferroni correction was used to adjust for the prespecified comparisons in the PPT score; these P values have been multiplied by 4 for the comparison to alpha value of 0.05. Secondary analyses included a comparison between diet–exercise and control; all P values were less than 0.05.
P<0.001 for the comparison of the value at the follow-up time with the baseline value within the group, as calculated with the use of mixed-model repeated-measures analysis of variance.
P<0.01 for the comparison of the value at the follow-up time with the baseline value within the group, as calculated with the use of mixed-model repeated-measures analysis of variance.
P<0.05 for the comparison of the value at the follow-up time with the baseline value within the group, as calculated with the use of mixed-model repeated-measures analysis of variance.
One-repetition maximum (1RM) is the maximal weight lifted at one time; the totals listed here are the sum of the maximal weights lifted in the biceps curl, bench press, seated row, knee extension, knee flexion, and leg press exercises. To convert the values to kilograms, divide by 2.2.