Table 1.
Subject characteristics and outcome measures
| PL |
MO |
TE |
||||
|---|---|---|---|---|---|---|
| Mean ± sd | n | Mean ± sd | n | Mean ± sd | n | |
| Baseline characteristics of the subjects | ||||||
| Demographic factors | ||||||
| Age (yr) | 65 ± 3a | 8 | 72 ± 8b | 8 | 73 ± 8b | 8 |
| Race or ethnic group (%)c | ||||||
| Caucasian | 87.5% | 7 | 100% | 8 | 87.5% | 7 |
| Minority | 12.5% | 1 | 0% | 0 | 12.5% | 1 |
| Body composition | ||||||
| Weight (kg) | 94 ± 19 | 8 | 81 ± 11 | 8 | 84 ± 9 | 8 |
| Body mass index (kg/m2) | 31 ± 6 | 8 | 28 ± 3 | 8 | 27 ± 2 | 8 |
| LBM (kg)e | 62 ± 10 | 8 | 57 ± 7 | 8 | 58 ± 6 | 8 |
| Fat mass (kg)e | 30 ± 11 | 8 | 22 ± 5 | 8 | 23 ± 4 | 8 |
| Body fat (%)e | 31 ± 5 | 8 | 27 ± 5 | 8 | 28 ± 3 | 8 |
| Muscle strength | ||||||
| Arm curl (kg) | 39 ± 12 | 8 | 39 ± 10 | 8 | 32 ± 9 | 8 |
| Leg curl (kg) | 46 ± 6 | 8 | 44 ± 7 | 8 | 40 ± 9 | 8 |
| Arm extension (kg) | 40 ± 9 | 8 | 41 ± 14 | 8 | 38 ± 9 | 8 |
| Leg extension (kg) | 70 ± 21 | 8 | 73 ± 15 | 8 | 66 ± 16 | 8 |
| Serum biochemical levels | ||||||
| Hematocrit (%) | 43 ± 3 | 8 | 40 ± 1 | 8 | 41 ± 3 | 8 |
| Fasting glucose (mg/dl) | 92 ± 7 | 7 | 92 ± 7 | 8 | 86 ± 7 | 8 |
| Alkaline phosphatase (U/liter) | 73 ± 12 | 8 | 69 ± 10 | 8 | 66 ± 14 | 8 |
| Alanine transferase (U/liter) | 44 ± 20 | 8 | 38 ± 10 | 8 | 32 ± 15 | 8 |
| Aspartate aminotransferase (U/liter) | 34 ± 16 | 8 | 29 ± 5 | 8 | 26 ± 11 | 8 |
| Albumin (g/dl) | 3.8 ± 0.2 | 8 | 3.9 ± 0.2 | 8 | 3.7 ± 0.3 | 8 |
| Hormones, lipids, and PSA | ||||||
| Total testosterone (ng/dl) | 344 ± 85 | 8 | 357 ± 103 | 8 | 341 ± 85 | 8 |
| Estradiol (pg/ml) | 38 ± 12 | 8 | 30 ± 6 | 8 | 30 ± 6 | 8 |
| IGF-I (ng/ml) | 101 ± 33 | 8 | 107 ± 38 | 8 | 104 ± 62 | 8 |
| SHBG (ng/dl) | 35 ± 10 | 8 | 36 ± 18 | 8 | 32 ± 13 | 8 |
| Total cholesterol (mg/dl) | 172 ± 30 | 8 | 181 ± 32 | 8 | 166 ± 49 | 8 |
| HDL cholesterol (mg/dl) | 40 ± 7 | 8 | 44 ± 9 | 8 | 43 ± 10 | 8 |
| LDL cholesterol (mg/dl) | 104 ± 26 | 8 | 106 ± 32 | 8 | 100 ± 43 | 8 |
| Triglycerides (mg/dl) | 142 ± 55 | 8 | 154 ± 52 | 8 | 116 ± 24 | 8 |
| PSA (mg/dl) | 1.24 ± 1.20 | 7 | 1.58 ± 1.04 | 8 | 2.09 ± 1.09 | 8 |
| Mean changes between baseline and month 5 | ||||||
| Body composition | ||||||
| Weight (kg) | 0.54 ± 1.55 | 8 | 1.70 ± 1.22f | 8 | 1.66 ± 1.58f | 8 |
| Body mass index (kg/m2) | 0.16 ± 0.50 | 8 | 0.57 ± 0.41g | 8 | 0.56 ± 0.52 | 8 |
| LBM (kg)d,e | −1.09 ± 1.64 | 8 | 2.67 ± 1.37f,g | 8h | 3.12 ± 2.06f,g | 8 |
| Fat mass (kg)e | 1.20 ± 1.87 | 8 | −0.80 ± 0.87 | 8h | −1.24 ± 0.95g | 8 |
| Body fat (%)e | 1.53 ± 1.77 | 8 | −1.69 ± 1.10g | 8h | −2.09 ± 1.11g | 8 |
| Muscle strength | ||||||
| Arm curl (kg)d | 0.56 ± 4.58 | 8 | 5.95 ± 7.36 | 8 | 4.99 ± 3.63g | 7j |
| Leg curl (kg)d | 2.83 ± 5.16 | 8 | 6.15 ± 4.08g | 7i | 9.72 ± 6.34g | 7j |
| Arm extension (kg)d | 1.98 ± 2.58 | 8 | 4.53 ± 5.44 | 8 | 6.74 ± 1.84g | 7j |
| Leg extension (kg)d | 2.26 ± 9.54 | 8 | 11.98 ± 10.96 | 7i | 13.48 ± 7.25g | 7j |
| Serum biochemical levels | ||||||
| Hematocrit (%) | −1.09 ± 1.00g | 8 | 1.89 ± 0.47f,g | 8 | 2.80 ± 1.93f,g | 8 |
| Fasting glucose (mg/dl) | −2.88 ± 5.24 | 8 | 3.38 ± 4.32 | 8 | −1.75 ± 4.45 | 8 |
| Alkaline phosphatase (U/liter) | −2.38 ± 6.81 | 8 | −6.62 ± 5.01g | 8 | −6.50 ± 5.62 | 8k |
| Alanine transferase (U/liter) | −3.63 ± 7.63 | 8 | −4.63 ± 4.67 | 8 | −3.15 ± 5.15 | 8k |
| Aspartate aminotransferase (U/liter) | −0.38 ± 5.76 | 8 | −1.00 ± 2.79 | 8 | −2.63 ± 5.00 | 8k |
| Albumin (g/dl) | −0.09 ± 0.11 | 8 | −0.34 ± 0.16g | 8 | −0.33 ± 0.18g | 8 |
| Hormones, lipids, and PSA | ||||||
| Total testosterone (ng/dl) | −45.01 ± 50.46 | 8 | 307.69 ± 193.74f,g | 8 | 317.39 ± 172.07f,g | 8 |
| Estradiol (pg/ml) | −7.00 ± 3.87g | 8 | 24.50 ± 11.95f,g | 8 | 33.25 ± 15.94f,g | 8 |
| IGF-I (ng/ml) | −6.21 ± 20.68 | 8 | 14.25 ± 13.31 | 8 | 19.69 ± 28.72 | 8 |
| SHBG (ng/dl) | −1.16 ± 6.14 | 8 | −1.19 ± 6.69 | 8 | −2.60 ± 5.45 | 8 |
| Total cholesterol (mg/dl) | −1.50 ± 6.01 | 8 | −6.00 ± 28.24 | 8 | −28.0 ± 24.71 | 8 |
| HDL cholesterol (mg/dl) | −1.63 ± 3.14 | 8 | −7.36 ± 5.18g | 8 | −4.75 ± 3.41g | 8 |
| LDL cholesterol (mg/dl) | 3.75 ± 7.15 | 8 | 1.25 ± 22.99 | 8 | −19.25 ± 22.15 | 8k |
| Triglycerides (mg/dl) | −18.25 ± 23.28 | 8 | 6.13 ± 41.11 | 8 | −25.13 ± 11.70g | 8 |
| PSA (mg/dl) | 0.06 ± 0.13 | 8 | 0.28 ± 0.33 | 8k | 0.54 ± 0.29f,g | 8 |
Results are shown as mean ± sd unless indicated otherwise. LDL, Low-density lipoprotein; PSA, prostate-specific antigen.
a,b
Means with different letters are significantly different at baseline.
c
Self-reported.
d
The category is a primary outcome variable.
e
Body composition variables were measured by DXA.
f
Change is significantly different from PL (ANOVA, P ≤ 0.05).
g
Significant change between months 0 and 5 (t test, P ≤ 0.05).
h
DXA data were not available at month 5 for one subject, and data from month 4 were used instead.
i
Leg strength measures were uncomfortable for one subject and were discontinued.
j
Strength measures were not performed by one subject at months 4 and 5.
k
Serum biochemical levels were not available at month 5 for one subject, and month 4 data were used instead.