This study was conducted to identify behavioral characteristics of salty food intake according to saline sensitivity of adults living in a rural area. Anthropometry and blood pressure were measured and salt intake-related dietary behavior was surveyed by questionnaires through interviews with 402 subjects aged ≥ 40 years in Chungcheongbuk-Do, Korea. The percentages of overweight and obese among the subjects were 37.8% and 3.8% respectively. Mean blood pressure of the subjects was in the normal range, but the distribution of subjects who were normotensive, high normal, and hypertensive was 48.7%, 17.7%, and 33.6% respectively. Approximately 27% of all subjects habitually consumed salty food, which was the smallest group, followed by 38.1% normal and 35.1% not-salty food. However, 34.6% of the eldest group of ≥ 65 years consumed salty food. The saline insensitive group showed a higher percentage of irregular meals, overeating, speed-eating, an unbalanced diet, a preference for fried food, and habitual intake of salty foods. These subjects recognized the risk for eating salty food, but they lacked the will to reduce their salty food intake. Compared to spouses and family members, experts such as doctors, nurses, and dieticians were the most influential for reducing the salty food intake of subjects. Saline sensitive group had relatively better control over salty food intake at every meal, eating out, and even when eating salty food that the spouse preferred. The saline sensitive group ate more frequently vegetables and fruits, whereas the saline insensitive group ate more frequently hot spicy foods. In conclusion, the results suggest that it is necessary to establish a social atmosphere toward reducing salt intake at the level of the government and food industry and to set action plans to be available for nutrition education programs to reduce salt intake nationwide.
General characteristics of the subjects by sex
Variable | Males | Females | Total | p-value |
---|---|---|---|---|
Age (yrs) | ||||
-40 | 001 (000.8) |
011 (004.1) | 012 (03.0) | NS |
41-50 | 034 (025.6) |
047 (017.5) | 081 (020.1) | |
51-60 | 033 (024.8) |
081 (030.1) | 114 (028.4) | |
61-70 | 054 (033.5) |
107 (039.8) | 161 (040.0) | |
71- | 011 (0v8.3) |
023 (008.6) | 034 (008.5) | |
Total | 133 (100.0) |
269 (100.0) | 402 (100.0) | |
Education | 0.000 |
|||
No schooling | 009 (007.0) |
057 (021.3) | 066 (016.7) | |
Primary school | 046 (035.7) |
125 (046.8) | 171 (043.2) | |
Middle school | 033 (025.6) |
040 (015.0) | 073 (018.4) | |
High school | 032 (024.8) |
037 (013.9) | 069 (017.4) | |
College or over | 009 (0v7.0) |
008 (003.0) | 017 (004.3) | |
Total | 129 (100.0) |
267 (100.0) | 396 (100.0) | |
Spouse | 0.000 |
|||
Yes | 116 (089.9) |
0197 (074.1) | 313 (079.2) | |
No | 013 (010.1) |
069 (025.9) | 082 (020.8) | |
Total | 129 (100.0) |
266 (100.0) | 395 (100.0) | |
Occupation | NS |
|||
Agriculture | 063 (047.7) |
117 (043.5) | 180 (044.9) | |
Not agriculture | 053 (040.2) |
112 (045.4) | 175 (043.6) | |
Unoccupied | 016 (012.1) |
030 (011.2) | 046 (011.5) | |
Total | 132 (100.0) |
269 (100.0) | 401 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
p < 0.001)
NS means ‘Not Significant’
Anthropometric characteristics and blood pressure of the subjects by age
Variable | Age (yrs) | Total | p-value | ||
---|---|---|---|---|---|
<50 | 50-65 | 65≤ | |||
Height (cm) | |||||
Male | 166.1 ± 6.7 | 163.8 ± 7.5 | 162.5 ± 8.0 | 163.8 ± 7.6 | 0.075 |
Female | 156.9 ± 5.8 |
156.2 ± 7.5 |
153.1 ± 7.9 |
155.2 ± 7.5 | 0.002 |
Total | 159.5 ± 7.3 |
158.9 ± 8.4 |
156.0 ± 9.0 |
158.0 ± 8.5 | 0.003 |
Weight (kg) | |||||
Male | 65.5 ± 11.5 |
65.1 ± 10.1 |
59.0 ± 9.5 |
63.2 ± 10.5 | 0.014 |
Female | 58.9 ± 8.2 | 60.4 ± 9.9 | 58.3 ± 9.4 | 59.3 ± 9.4 | 0.740 |
Total | 60.8 ± 9.7 |
62.0 ± 10.2 |
58.5 ± 9.4 |
60.6 ± 9.9 | 0.100 |
BMI (kg/m2) |
|||||
Male | 23.9 ± 2.9 | 24.3 ± 3.5 | 22.4 ± 3.5 | 23.6 ± 3.5 | 0.083 |
Female | 23.9 ± 3.3 | 24.7 ± 3.6 | 24.8 ± 3.2 | 24.6 ± 3.3 | 0.121 |
Total | 23.9 ± 3.2 | 24.6 ± 3.5 | 24.1 ± 3.5 | 24.3 ± 3.4 | 0.763 |
Arm circumference (cm) | |||||
Male | 29.3 ± 2.5 |
28.8 ± 3.1 |
27.4 ± 2.7 |
28.4 ± 2.9 | 0.014 |
Female | 28.5 ± 3.1 | 29.0 ± 3.0 | 28.9 ± 6.8 | 28.8 ± 4.7 | 0.610 |
Total | 28.7 ± 2.9 | 28.9 ± 3.0 | 28.4 ± 5.9 | 28.7 ± 4.2 | 0.642 |
WHR |
|||||
Male | 0.85 ± 0.10 | 0.92 ± 0.13 | 0.89 ± 0.09 | 0.90 ± 0.12 | 0.242 |
Female | 0.85 ± 0.06 | 0.98 ± 0.74 | 0.90 ± 0.05 | 0.92 ± 0.49 | 0.521 |
Total | 0.85 ± 0.07 | 0.95 ± 0.57 | 0.89 ± 0.63 | 0.91 ± 0.39 | 0.405 |
SBP (mmHg) |
|||||
Male | 126.2 ± 12.8 | 126.6 ± 13.6 | 126.2 ± 13.9 | 126.4 ± 13.5 | 0.995 |
Female | 120.4 ± 15.0 |
125.5 ± 13.2 |
127.9 ± 14.9 |
125.3 ± 14.4 | 0.002 |
Total | 122.1 ± 14.5 |
125.9 ± 13.4 |
127.4 ± 14.6 |
125.7 ± 10.1 | 0.008 |
DBP (mmHg) |
|||||
Male | 81.7 ± 14.4 | 84.4 ± 10.7 | 80.9 ± 9.9 | 82.8 ± 11.3 | 0.781 |
Female | 80.9 ± 11.2 | 81.1 ± 9.9 | 83.0 ± 9.9 | 81.7 ± 10.2 | 0.224 |
Total | 81.1 ± 12.1 | 82.3 ± 10.3 | 82.3 ± 9.9 | 82.1 ± 10.6 | 0.418 |
Values were expressed by Mean ± SD. Significances were tested by ANOVA and Duncan’s multiple range test
p < 0.05
p < 0.01). Different letters
mean significant differences by age group
BMI (Body Mass Index, kg body weight/m2 Height)
WHR (Waist-Hip Ratio) = Waist (cm)/Hip (cm)
SBP : Systolic Blood Pressure
DBP : Diastolic Blood Pressure
Eating behavior related to salty food intake of the subjects by age
Variable | Age (yrs) | Total | p-value | ||
---|---|---|---|---|---|
<50 | 50-65 | 65≤ | |||
Which food do you take usually? | |||||
Salty food | 15 (019.2) |
046 (024.5) | 047 (034.6) | 108 (026.9) | 0.022 |
Normal food | 37 (047.5) |
065 (034.6) | 051 (037.5) | 153 (038.0) | |
Not salty food | 26 (033.3) |
077 (040.9) | 038 (027.9) | 141 (035.1) | |
Total | 78 (100.0) |
188 (100.0) | 136 (100.0) | 402 (100.0) | |
When I eat out, I feel that the food is | |||||
Salty | 18 (023.1) |
041 (021.8) | 034 (025.0) | 093 (023.1) | NS |
Normal | 47 (060.2) |
113 (060.1) | 080 (058.8) | 240 (059.7) | |
Not salty | 13 (016.7) |
034 (018.1) | 022 (006.2) | 069 (017.2) | |
Total | 78 (100.0) |
188 (100.0) | 136 (100.0) | 402 (100.0) | |
Compared with my offsprings’ taste, I choose food | |||||
More salty | 03 (003.8) |
014 (007.5) | 022 (016.1) | 039 (009.7) | 0.004 |
Similar salty | 56 (071.8) |
104 (055.3) | 070 (051.5) | 230 (057.2) | |
Less salty | 19 (024.4) |
070 (037.2) | 044 (032.4) | 133 (033.1) | |
Total | 78 (100.0) |
188 (100.0) | 136 (100.0) | 402 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
p < 0.05
p < 0.01)
NS means ‘Not Significant’
Sensory response on 1% saline solution of the subjects by age
Sensory response | Age (yrs) | Total | p-value | ||
---|---|---|---|---|---|
<50 | 50-65 | 65≤ | |||
Salty | 43 (055.1) |
99 (052.7) | 060 (044.1) | 202 (050.3) | NS |
Normal | 29 (037.2) |
75 (039.9) | 061 (044.9) | 165 (041.0) | |
Not salty | 06 (007.7) |
14 (007.4) | 015 (011.0) | 035 (008.7) | |
Total | 78 (100.0) |
188 (100.0) | 136 (100.0) | 402 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
NS means not significant at p < 0.05
Distribution of blood pressures of three groups by saline sensitivity
Variable | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
Systolic blood pressure | |||||
Normal | 117 (058.2) |
104 (062.7) | 019 (054.3) | 240 (059.7) | NS |
High normal | 051 (025.4) |
038 (022.9) | 007 (020.0) | 096 (023.9) | |
Hypertension | 033 (016.4) |
024 (014.5) | 009 (025.7) | 066 (016.4) | |
Total | 201 (100.0) |
166 (100.0) | 35 (100.0) | 402 (100.0) | |
Means ± SD | 126.0 ± 13.9 |
125.3 ± 14.2 | 125.4 ± 14.8 | 125.7 ± 10.1 | 0.8991 |
Diastolic blood pressure | |||||
Normal | 130 (064.7) |
108 (065.1) | 026 (074.3) | 264 (065.7) | NS |
High normal | 012 (006.0) |
011 (006.6) | 002 (005.7) | 025 (006.2) | |
Hypertension | 059 (029.4) |
047 (028.3) | 007 (020.0) | 113 (028.1) | |
Total | 201 (100.0) |
166 (100.0) | 035 (100.0) | 402 (100.0) | |
Means ± SD | 82.2 ± 10.7 |
082.8 ± 10.4 | 078.3 ± 1.01 | 082.1 ± 10.6 | 0.0727 |
Values were expressed by N (%) and significances were tested by chi-square test
NS means not significant at p < 0.05
Values are mean blood pressure by three sensitivity group. Significances were tested by ANOVA
Dietary behaviors of three groups by saline sensitivity
Variable | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
Regularity of meal time | |||||
Regular | 124 (061.4) |
114 (069.1) | 17 (048.6) | 255 (063.4) | NS |
Fair | 060 (029.7) |
041 (024.8) | 15 (042.9) | 116 (028.9) | |
Very Irregular | 018 (0v8.9) |
010 (006.1) | 03 (008.6) | 031 (07.7) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) | |
Amount of foods per meal | |||||
More than adequate | 053 (026.2) |
031 (018.9) | 11 (031.4) | 095 (023.7) | 0.016 |
Adequate | 105 (052.0) |
101 (061.6) | 11 (031.4) | 217 (054.1) | |
Less than adequate | 036 (017.8) |
024 (014.6) | 08 (022.9) | 068 (017.0) | |
Others | 008 (004.0) |
008 (004.9) | 05 (014.3) | 021 (005.2) | |
Total | 202 (100.0) |
164 (100.0) | 35 (100.0) | 401 (100.0) | |
Meal time (mim) | |||||
<10 | 081 (040.1) |
064 (038.8) | 18 (051.4) | 163 (040.5) | NS |
10-20 | 079 (039.1) |
073 (044.5) | 12 (034.3) | 164 (040.8) | |
20-30 | 033 (016.3) |
019 (011.5) | 05 (014.3) | 057 (014.2) | |
>30 | 009 (004.5) |
009 (005.5) | - | 018 (004.5) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) | |
Do you eat only what you wants? | |||||
Yes | 014 (0v6.9) |
008 (004.8) | 03 (008.6) | 025 (006.2) | NS |
A little bit | 029 (014.4) |
031 (018.8) | 08 (022.9) | 068 (016.9) | |
Rare or never | 159 (078.7) |
126 (076.3) | 24 (068.6) | 309 (076.8) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) | |
Frequency of snack | |||||
2-3 times/day | 047 (023.4) |
041 (024.9) | 04 (011.5) | 092 (023.0) | 0.087 |
once/day | 067 (033.3) |
071 (043.0) | 12 (034.3) | 150 (037.4) | |
None | 087 (043.3) |
053 (032.1) | 19 (054.3) | 159 (039.7) | |
Total | 201 (100.0) |
165 (100.0) | 35 (100.0) | 401 (100.0) | |
Frequency of eating out | |||||
1-2 times a day | 011 (005.5) |
013 (007.9) | 04 (011.4) | 028 (007.0) | NS |
once a week | 055 (027.4) |
040 (024.4) | 09 (025.7) | 104 (026.0) | |
once a month | 057 (028.4) |
048 (029.3) | 10 (028.6) | 115 (028.8) | |
None | 078 (038.8) |
063 (038.4) | 12 (034.3) | 153 (038.3) | |
Total | 201 (100.0) |
164 (100.0) | 35 (100.0) | 400 (100.0) | |
Favorate cooking method | |||||
Roasting | 120 (059.4) |
095 (057.6) | 15 (042.9) | 230 (057.2) | NS |
Panbroiling or Frying | 028 (013.9) |
025 (015.2) | 09 (025.7) | 062 (015.4) | |
Broiling | 015 (007.4) |
011 (006.7) | 03 (008.6) | 029 (007.2) | |
Boiling | 039 (019.3) |
034 (020.6) | 08 (022.9) | 081 (020.1) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
p < 0.05)
NS means ‘Not Significant’
Behavioral belief and self appraisal about salty food intake of three groups by saline sensitivity
Variable | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
Do you eat salty food habitually? | |||||
No | 063 (031.2) |
046 (028.4) | 04 (011.4) | 113 (028.3) | NS |
So so | 029 (014.4) |
024 (014.8) | 09 (025.7) | 062 (015.5) | |
Yes | 110 (054.5) |
092 (056.8) | 22 (062.9) | 024 (056.1) | |
Total | 202 (100.0) |
162 (100.0) | 35 (100.0) | 399 (100.0) | |
Do you think that salty food is not good for health? | |||||
Little | 008 (004.0) |
006 (003.6) | 01 (002.9) | 015 (003.7) | NS |
So so | 018 (008.9) |
018 (010.9) | 06 (017.1) | 042 (010.4) | |
Much | 176 (087.1) |
141 (085.5) | 28 (080.0) | 345 (085.8) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) | |
What do you think about the habitual intake of salty food? | |||||
Bad | 166 (083.4) |
113 (070.6) | 24 (070.6) | 303 (077.1) | 0.023 |
So so | 024 (012.1) |
028 (017.5) | 05 (014.7) | 057 (014.5) | |
Not bad | 009 (004.5) |
019 (011.9) | 05 (014.7) | 033 (008.4) | |
Total | 199 (100.0) |
160 (100.0) | 34 (100.0) | 393 (100.0) | |
Do you need to reduce salt intake in your diet? | |||||
Yes | 093 (046.0) |
101 (061.2) | 16 (045.7) | 210 (052.2) | 0.032 |
A little bit | 048 (023.8) |
033 (020.0) | 07 (020.0) | 088 (021.9) | |
No | 061 (030.2) |
031 (018.8) | 12 (034.3) | 104 (025.9) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) | |
Do you try to reduce salt intake? | |||||
Yes | 043 (021.3) |
027 (016.4) | 05 (014.3) | 075 (018.7) | NS |
A little bit | 061 (030.2) |
066 (040.0) | 09 (025.7) | 136 (033.8) | |
No | 098 (048.5) |
072 (043.6) | 21 (060.0) | 191 (047.5) | |
Total | 202 (100.0) |
165 (100.0) | 35 (100.0) | 402 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
p < 0.05)
NS means ‘Not Significant’
Supports and influences by the family members or experts of three groups by saline sensitivity
Variable | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
Supports by family members or experts | |||||
Your spouse respond as | |||||
Opposite | 025 (017.9) |
024 (020.3) | 07 (024.1) | 056 (019.5) | NS |
So so | 052 (037.1) | 044 (037.3) | 12 (041.4) | 108 (037.6) | |
Support | 063 (045.0) | 050 (042.4) | 10 (034.5) | 123 (042.9) | |
Total | 140 (100.0) | 118 (100.0) | 29 (100.0) | 287 (100.0) | |
Offspring and relative respond as | |||||
Opposite | 017 (010.6) | 025 (018.1) | 10 (031.3) | 052 (015.7) | 0.043 |
So so | 058 (036.0) | 043 (031.2) | 08 (025.0) | 109 (032.9) | |
Support | 086 (053.4) | 070 (050.7) | 14 (043.8) | 170 (051.4) | |
Total | 161 (100.0) | 138 (100.0) | 32 (100.0) | 331 (100.0) | |
Doctor, nurse and dietician respond as | |||||
Opposite | 008 (007.1) | 014 (014.4) | 07 (033.3) | 029 (012.6) | 0.006 |
So so | 039 (034.5) | 022 (022.7) | 06 (028.6) | 067 (029.0) | |
Support | 066 (058.4) | 061 (062.9) | 08 (038.1) | 135 (058.4) | |
Total | 113 (100.0) | 097 (100.0) | 21 (100.0) | 231 (100.0) | |
Influences by family members or experts | |||||
By spouse | |||||
Little | 029 (017.7) | 033 (025.2) | 011 (037.9) | 073 (022.5) | 0.058 |
So so | 047 (028.7) | 037 (028.2) | 10 (034.5) | 094 (029.0) | |
Much | 088 (053.7) | 061 (046.6) | 08 (027.6) | 157 (048.5) | |
Total | 164 (100.0) | 131 (100.0) | 29 (100.0) | 324 (100.0) | |
By offspring or relatives? |
|||||
Little | 040 (020.9) | 036 (023.4) | 13 (038.2) | 089 (023.5) | NS |
So so | 057 (029.8) | 052 (033.8) | 10 (029.4) | 119 (031.4) | |
Much | 094 (049.2) | 066 (042.9) | 11 (032.4) | 171 (045.1) | |
Total | 191 (100.0) | 154 (100.0) | 34 (100.0) | 379 (100.0) | |
By doctors, nurses and dieticians | |||||
Little | 019 (013.9) | 019 (017.0) | 09 (040.9) | 047 (017.3) | 0.001 |
So so | 029 (021.2) | 032 (028.6) | 09 (040.9) | 070 (025.8) | |
Much | 089 (065.0) | 061 (054.5) | 04 (018.2) | 154 (056.8) | |
Total | 137 (100.0) | 112 (100.0) | 22 (100.0) | 271 (100.0) |
Values were expressed by N (%) and significances were tested by chi-square test
p < 0.05
p < 0.01)
NS means ‘Not Significant’
Perceived control against salty food intake of three groups by saline sensitivity
Variable | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
In every meal | |||||
Hard | 062 (037.8) |
071 (049.7) | 25 (073.5) | 158 (046.3) | 0.001 |
So so | 053 (032.3) |
046 (032.2) | 07 (020.6) | 106 (031.1) | |
Not hard | 049 (029.9) |
026 (018.2) | 02 (005.9) | 077 (022.6) | |
Total | 164 (100.0) |
143 (100.0) | 34 (100.0) | 341 (100.0) | |
In eating out | |||||
Hard | 053 (034.0) |
049 (035.5) | 16 (051.6) | 118 (036.3) | NS |
So so | 067 (042.9) |
053 (038.4) | 12 (038.7) | 132 (040.6) | |
Not hard | 036 (023.1) |
036 (026.1) | 03 (009.7) | 075 (023.1) | |
Total | 156 (100.0) |
138 (100.0) | 31 (100.0) | 325 (100.0) | |
When spouse likes salty food | |||||
Hard | 054 (044.3) |
044 (041.9) | 16 (064.0) | 114 (045.2) | NS |
So so | 048 (039.3) |
044 (041.9) | 08 (032.0) | 100 (039.7) | |
Not hard | 020 (016.4) |
017 (016.2) | 01 (004.0) | 038 (015.1) | |
Total | 122 (100.0) |
105 (100.0) | 25 (100.0) | 252 (100.0) |
1) Values were expressed by N (%) and significances were tested by chi-square test (∗: p < 0.05
p < 0.01)
NS means ‘Not Significant’
Monthly intake frequency of major food and some specific food groups by saline sensitivity
Food groups | Sensitive group | Moderate group | Insensitive group | Total | p-value |
---|---|---|---|---|---|
Meats, chickens, Eggs | 9.2 ± 11.8 |
6.9 ± 10.8 | 12.2 ± 17.1 | 8.5 ± 12.0 | 0.975 |
Fishes | 8.0 ± 10.7 | 7.4 ± 11.9 | 6.3 ± 11.9 | 7.6 ± 11.3 | 0.412 |
Legumes | 23.0 ± 25.5 | 23.5 ± 23.9 | 13.7 ± 19.5 | 22.4 ± 24.4 | 0.177 |
Nuts and seeds | 2.8 ± 8.6 | 1.6 ± 6.5 | 2.1 ± 5.3 | 2.3 ± 7.6 | 0.222 |
Vegetables | 44.8 ± 26.8 |
41.0 ± 26.5 |
29.3 ± 24.2 |
41.9 ± 26.7 | 0.003 |
Seaweeds and mushrooms | 11.2 ± 16.2 | 10.1 ± 13.4 | 10.9 ± 16.8 | 10.7 ± 15.1 | 0.915 |
Fruits | 22.1 ± 22.2 |
17.0 ± 16.6 |
13.6 ± 19.5 |
19.3 ± 20.0 | 0.003 |
Milk and daily | 13.8 ± 18.6 | 13.9 ± 15.6 | 9.3 ± 14.9 | 13.4 ± 17.1 | 0.157 |
Oils | 24.1 ± 21.4 | 26.6 ± 22.8 | 25.7 ± 26.1 | 25.3 ± 22.4 | 0.695 |
Kimchies | 51.0 ± 24.0 | 45.5 ± 27.1 | 47.6 ± 28.4 | 48.4 ± 25.8 | 0.109 |
Hot food | 12.4 ± 18.8 |
12.8 ± 18.0 |
26.1 ± 29.2 |
13.8 ± 19.9 | 0.006 |
Fried food | 1.6 ± 3.8 | 1.8 ± 3.4 | 3.1 ± 11.8 | 1.8 ± 4.9 | 0.207 |
Processed meat and fish products | 0.8 ± 2.2 | 0.8 ± 2.6 | 0.5 ± 1.2 | 0.8 ± 2.3 | 0.521 |
Preserved salted food | 10.2 ± 17.7 | 11.2 ± 15.4 | 15.3 ± 22.4 | 11.1 ± 17.3 | 0.156 |
Values were expressed as monthly frequency by Mean ± SD. Significances were tested by ANOVA and Duncan’s multiple range test (∗: p < 0.05
p < 0.01)
Different letters
mean significant differences by age group