The participants’ average height was 156.8±7.6 cm, and the average weight was 59.1±10.3 kg. The average participation rate of the classes was 87.4% (range: 63.6%–100.0%).
The average muscle thickness at the AT of all participants was 26.65±5.12 mm before the training intervention, which significantly increased to 29.48±5.38 mm after undergoing the biweekly low-load resistance training program for 12 weeks (p<0.001, Figure 1A). The average serum Alb concentration at the AT of all participants was 4.25±0.25 g/dL before the training intervention, which significantly increased to 4.32±0.26 g/dL after the training program (p<0.001, Figure 1B).
Table 1. The first quartile value of each blood parameter
|
Unit
|
Mean
|
Minimum
|
Maximum
|
1st Quartile Value
|
Value
|
Value
|
Value
|
WBC
|
/µL
|
5369.6
|
2800
|
8400
|
4400
|
RBC
|
×104/µL
|
439.7
|
366
|
552
|
414
|
Hb
|
g/dL
|
13.2
|
10.3
|
16.2
|
12.6
|
Ht
|
%
|
39.64
|
32.8
|
48
|
37.9
|
MCV
|
fL
|
90.35
|
77.5
|
101
|
87.7
|
MCH
|
pg
|
30.09
|
25.5
|
33.5
|
29.2
|
MCHC
|
%
|
33.3
|
30.9
|
34.7
|
32.8
|
PLT
|
×104/µL
|
22.78
|
13.2
|
47.1
|
18.8
|
TP
|
g/dL
|
7.23
|
6.6
|
8
|
7
|
Alb
|
g/dL
|
4.25
|
3.7
|
4.9
|
4.1
|
AST(GOT)
|
U/L
|
21.6
|
12
|
41
|
18
|
ALT(GPT)
|
U/L
|
19.4
|
7
|
63
|
14
|
ALP
|
U/L
|
216.7
|
74
|
387
|
178
|
LAP
|
U/L
|
48.2
|
32
|
83
|
45
|
LD(LDH)
|
U/L
|
190.9
|
135
|
276
|
169
|
γ-GTP
|
U/L
|
23.4
|
10
|
107
|
14
|
TG
|
mg/dL
|
140.7
|
46
|
393
|
85
|
TC
|
mg/dL
|
209.7
|
148
|
307
|
181
|
HDL-C
|
mg/dL
|
62.2
|
29
|
101
|
52
|
LDL-C
|
mg/dL
|
121.2
|
64
|
211
|
102
|
HbA1c
|
%
|
5.57
|
4.7
|
7.3
|
5.3
|
FBS
|
mg/dL
|
106.6
|
72
|
191
|
95
|
WBC, white blood cell count; RBC, red blood cell count; Hb, hemoglobin; Ht, hematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; PLT, platelet count; TP, total protein; Alb, albumin; AST(GOT), aspartate aminotransferase (glutamic oxaloacetic transaminase); ALT(GPT), alanine aminotransferase (glutamic pyruvic transaminase); ALP, alkaline phosphatase; LAP, leucine aminopeptidase; LD(LDH), lactate dehydrogenase; γ-GTP, γ-glutamyltransferase; TG, triglyceride; TC, total cholesterol; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; HbA1c, hemoglobin A1c; FBS, fasting blood sugar.
Using the blood parameter criteria, we checked the first quartile value of each blood parameter to establish the cutoff criteria for reduced levels (Table 1). When the two-way analysis of variance was conducted, the effects were significant for time, but not for group, and the time × group interactions were significant for low (<32.8%) versus normal (≥32.8%) MCHC levels, low (<4.1 g/dL) versus normal (≥4.1 g/dL) serum Alb levels, and low (<102 mg/dL) versus normal (≥102 mg/dL) serum LDL-C levels (p<0.05; Table 2). The time × group interactions were detected in the serum Alb levels. When comparing the low and normal serum Alb level groups using the simple main effects analysis, there was no difference in muscle thickness at the AT before the training intervention; however, participants in the normal serum Alb level group had greater muscle thickness after the training intervention than those in the low serum Alb level group (30.26±5.31 mm, 26.45±4.68 mm, p<0.001; Figure 2A). To verify the effect of participation rate of the classes, an analysis of covariance was conducted. Although regression parallelism was confirmed, the regression was not significant. Time × group interactions were also detected in the MCHC and serum LDL-C levels (p<0.001; Table 2), but no differences in muscle thickness at the AT either before or after the training intervention were observed between the low and normal groups, using the simple main effects analysis (Figure 2B, 2C).
Table 2. Summarized the results of the two-way analysis of variance
|
n
|
muscle thickness(mm)
|
time
|
group
|
interaction
|
|
pre
|
pre
|
post
|
|
low
|
normal
|
low
|
normal
|
low
|
normal
|
p value
|
WBC
|
17
|
52
|
23.9±4.6
|
27.6±5.0
|
27.7±5.3
|
30.1±5.3
|
< 0.001
|
0.0306
|
0.082
|
RBC
|
17
|
52
|
24.5±4.6
|
27.3±5.1
|
27.4±5.2
|
30.2±5.3
|
< 0.001
|
0.0461
|
0.9887
|
Hb
|
16
|
53
|
23.8±3.1
|
27.5±5.3
|
26.8±3.9
|
30.3±5.5
|
< 0.001
|
0.0118
|
0.8063
|
Ht
|
17
|
52
|
25.2±4.4
|
27.1±5.3
|
27.7±5.2
|
30.1±5.4
|
< 0.001
|
0.1295
|
0.5764
|
MCV
|
17
|
52
|
26.7±5.0
|
26.6±5.2
|
29.1±4.7
|
29.6±5.6
|
< 0.001
|
0.8868
|
0.5129
|
MCH
|
17
|
52
|
25.2±4.6
|
27.1±5.2
|
28.7±4.8
|
29.8±5.6
|
< 0.001
|
0.297
|
0.2858
|
MCHC
|
13
|
56
|
25.0±5.8
|
27.0±4.9
|
29.5±4.8
|
29.5±5.5
|
< 0.001
|
0.5249
|
0.0146
|
PLT
|
17
|
52
|
27.1±5.1
|
26.5±5.2
|
29.5±4.4
|
29.5±5.7
|
< 0.001
|
0.8204
|
0.4596
|
TP
|
17
|
52
|
23.4±3.6
|
27.7±5.1
|
26.9±4.9
|
30.3±5.3
|
< 0.001
|
0.0057
|
0.2622
|
Alb
|
14
|
55
|
25.4±5.1
|
27.0±5.1
|
26.5±4.7
|
30.3±5.3
|
< 0.001
|
0.0791
|
0.003
|
AST(GOT)
|
16
|
53
|
27.1±4.4
|
26.5±5.4
|
30.4±4.7
|
29.2±5.6
|
< 0.001
|
0.5378
|
0.4372
|
ALT(GPT)
|
15
|
54
|
24.6±3.2
|
27.2±5.4
|
27.6±4.0
|
30.0±5.6
|
< 0.001
|
0.0902
|
0.8594
|
ALP
|
15
|
54
|
27.3±5.4
|
26.5±5.1
|
30.0±5.7
|
29.3±5.3
|
< 0.001
|
0.6309
|
0.8943
|
LAP
|
16
|
53
|
24.8±3.9
|
27.2±5.4
|
27.9±4.0
|
30.0±5.7
|
< 0.001
|
0.1252
|
0.6677
|
LD(LDH)
|
17
|
52
|
28.7±4.6
|
26.0±5.1
|
31.3±5.0
|
28.9±5.4
|
< 0.001
|
0.068
|
0.5984
|
γ-GTP
|
14
|
55
|
23.8±3.6
|
27.4±5.2
|
26.2±3.6
|
30.3±5.5
|
< 0.001
|
0.0105
|
0.4903
|
TG
|
17
|
52
|
23.6±3.3
|
27.6±5.2
|
26.4±4.3
|
30.5±5.4
|
< 0.001
|
0.0038
|
0.9606
|
TC
|
17
|
52
|
27.4±4.8
|
26.4±5.3
|
29.3±5.7
|
29.5±5.3
|
< 0.001
|
0.7951
|
0.1247
|
HDL-C
|
17
|
52
|
28.7±4.7
|
26.0±5.1
|
32.0±4.1
|
28.7±5.5
|
< 0.001
|
0.0326
|
0.4299
|
LDL-C
|
17
|
52
|
27.2±5.8
|
26.5±4.9
|
28.7±5.6
|
29.7±5.3
|
< 0.001
|
0.9126
|
0.0105
|
HbA1c
|
15
|
54
|
28.1±4.8
|
26.3±5.2
|
31.1±4.2
|
29.0±5.6
|
< 0.001
|
0.1987
|
0.7482
|
FBS
|
16
|
53
|
27.0±5.7
|
26.6±5.0
|
30.7±5.5
|
29.1±5.3
|
< 0.001
|
0.4946
|
0.102
|
Data of muscle thickness are presented as mean±SD.
WBC, white blood cell count; RBC, red blood cell count; Hb, hemoglobin; Ht, hematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; PLT, platelet count; TP, total protein; Alb, albumin; AST(GOT), aspartate aminotransferase (glutamic oxaloacetic transaminase); ALT(GPT), alanine aminotransferase (glutamic pyruvic transaminase); ALP, alkaline phosphatase; LAP, leucine aminopeptidase; LD(LDH), lactate dehydrogenase; γ-GTP, γ-glutamyltransferase; TG, triglyceride; TC, total cholesterol; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; HbA1c, hemoglobin A1c; FBS, fasting blood sugar.
To verify the influence that serum Alb concentration and serum Alb levels (<4.1 g/dL or not) had on the change in muscle thickness at the AT, binomial logistic regression analysis was performed with muscle thickness at the AT (increased as 0, decreased as 1) as a target variable and with the serum Alb concentration and serum Alb level (>=4.1 g/dL as 0, <4.1 g/dL as 1) as explanatory variables. The serum Alb level was selected as a significant variable (p=0.0102), and the odds ratio for decreasing muscle thickness at the AT was 7.08, while the 95% confidence interval was 1.59–31.54.