Yearbook on Journal of the Japan Society of Nursing Research 2015

Factors Affecting Bone Mineral Density of Postmenopausal Japanese Women
Taeko Miyajima1), Osamu Uyama2), Tomoko Kirimura2), Hidesuke Kaji2), Yoshio Yoshimoto3)
Key Words :Bone mineral Density
Nutrition
AgeingMenopause

I. Introduction

ABSTRACTThis study was performed on 53 postmenopausal women to evaluate how factors, such as the number ofyears after menopause and nutrition uptake status, are related with total bone mineral density (BMD),
lumbar spine BMD, and broadband ultrasound attenuation (BUA) of calcaneus. The subjects were divided into
3 age groups: 20 subjects in the sixties, 24 subjects in the seventies, and 9 subjects in the eighties and older.
As a result, in the group of the sixties, the number of years after menopause showed significant negative
correlation with BMD, while significant correlation was not found in the groups of the seventies and theeighties and older. In BMD and nutrition uptake status, no significant correlation was found in the groupsof the sixties and the seventies. On the other hand, in the group of the eighties and older, significant positive
correlation was seen between total BMD and protein uptake (r = 0.740; p < 0.05) or vitamin B1 uptake (r =0.720; p < 0.05), and also between lumbar spine BMD and calcium uptake (r = 0.685; p < 0.05), and further,between calcaneal BUA and iron uptake (r = 0.893; n = 6). These results suggest that the number of years
after menopause exerts influence on BMD and/or BUA in the group of the eighties, while nutrition uptake
status gives influence in the groups of the eighties and older.

than aging) related to BMD in postmenopausal women anddiscover possible nursing interventions to help the elderly
maintain BMD. To achieve these aims, total BMD, lumbar spine
BMD, and the broadband ultrasound attenuation (BUA) of thecalcaneus were measured, and their potential correlation withbody weight, postmenopausal years, and nutrition intake
status were analyzed.

Worldwide, Japan has the longest overall life expectancy.
In 2000, there were 21,870,000 Japanese citizens more than
65 years old (roughly one out of every six people, with an
aging rate of 17.2%), and in the last 30 years there has beena dramatic spike in the rapid aging of society1). This has
led to unique medical issues. In postmenopausal women,
especially, bone mineral density (BMD) and bone mineralcontent are known to decrease rapidly2), which can causebone fractures and affect life expectancy in the elderly. In
addition, there is a strong correlation between BMD and themortality rates of women in their seventies3). This kind of
involutional osteoporosis is divided into two types based on
its pathogenesis and characteristics: either postmenopausal
osteoporosis (51-75 years old) caused by menopause-related
factors and individual, or senile, osteoporosis (more than 70
years old) brought on by aging 4). Much remains unclear about
the possible causes of senile osteoporosis. Some individuals
more than 75 years old maintain their bone mineraldensity; clearly, factors that can prevent age-related BMD
loss exist. Studied factors known to decrease BMD include
body weight, lean mass, and fat mass5); postmenopausal
years6-8); and nutrition uptake status9-18). With regards tobone mineral density and nutrition, Huang et al.9) conducteda follow-up study on Caucasian women (45-77 years old)
who had experienced a femoral neck fracture and foundthat the number of fractures was positively correlated withpoor nutrition, blood albumin concentration, body weight,
and a low body fat percentage. In addition, Yukawa et al.10)
conducted a long-term longitudinal study of Japanese women(65-79 years old), in which certain nutrients and food, besides
acting specifically on BMD, were found to improve women’s
overall nutritional status and effectively maintain bone mass.
Previous reports, however, have focused little on women older
than eighty2-18).
Accordingly, this study aimed to elucidate factors (other

II. Research Methods
A. Subjects

From April 1, 1999 to November 30, 2000, 24 students at
A City University for the Elderly (16 in their sixties, 8 in theirseventies, 0 in their eighties) and 29 nursing home residents(4 in their sixties, 16 in their seventies, 9 in their eighties)
participated in this study, independent of their daily activities.
A total of 53 postmenopausal women were involved (60-92
years old, average age of 71.8 ± 7.2 years, average weight of
49.9 ± 7.7 kg, average height of 149.8 ± 4.3 cm). Among those
who had hormone replacement therapy and women who had
premature menopause (younger than 40 years), those who
had both ovaries removed were excluded.
B. Method for Measuring BMD

By using the Dual Energy X-ray Absorptiometry method(DEXA, Norlanzd XR-26, Norland, USA), total BMD and specific
BMDS were measured. The lumbar spine (L2-L4) BMD wasused as a diagnostic reference for osteoporosis and decreasein bone mass. In addition, the calcaneus’ BMD was used as amarker for the risk of femoral neck fractures and vertebral
compression fractures19). The BUA, which reflects bonestrength and BMD, of the calcaneus was measured using theultrasonic method (Ubis3000, Diagnostic Medical Systems,
France).
C. Methods of Survey by Questionnaire

1) University of Yamanashi Faculty of Medicine School of Nursing2) College of Nursing Art and Science, Hyogo
3) National Hyogo-Chuo Hospital

The subjects who gave BMD and/or BUA measurements
were sent an eating habits questionnaire and a medical
questionnaire by mail (76 sent, 53 collected; overall response

Corresponding author. Tel.: +81 858 27 2800
E-mail address: tmiyajima@ns.tcn.ac.jp (T. Miyajima)

11
This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2015

rate of 69.7%). The medical questionnaire was intended toanalyze the number of postmenopausal years. The eating
habits questionnaire asked subjects to fill in 3 days’ worth ofmeals, and, using diet analysis software (Nankodo’s NUTAS4for Windows Version 1.05a), information about their average
daily uptake of energy, protein, lipids, carbohydrates, calcium,
phosphorus, iron, vitamin A, vitamin B1, vitamin B2, andvitamin C was collected and analyzed. When residents used
the facility’s cafeteria, calculations were performed based on
the menu and how much was eaten.

results from the medical and eating habits questionnaire
were examined in a scatter plot using Pearson’s correlation
coefficient.
E. Ethical Considerations

For the execution of this study, the approval of the Hyogo
Prefectural College of Nursing’s Ethics Committee wasobtained.
III. Results

D. Analysis

A. Correlations of Subjects’ Physical Characteristics with BMD
and BUA

Data processing was performed using Halbou for Windows,
Version 5.22. Postmenopausal women’s BMD decreased
markedly with age2). As there were relatively few reports on
subjects older than 80 years old, there was also a relativelack of information regarding the correlation between their
BMD and nutritional status9-18). Based on the classifications ofinvolutional osteoporosis, three age groups were established,including 60-69 years old (sixties) where the primary causes of
BMD loss were considered to be postmenopausal osteoporosis
and menopause-related factors; 70-79 years old (seventies)
where the primary causes of BMD loss were considered to be
senile osteoporosis and aging; and 80-92 years old (eighties
and older or eighties plus) where, although there were very
few reports, primary causes of BMD loss were considered to
be senile osteoporosis and aging. There were some particularsite-specific bone mass variations when measuring BMD 20),so the three variables of total BMD, lumbar spine BMD, and
BUA were used. The BMD and BUA measurements and theTable 1 shows the average and standard deviation for
physical characteristics and measurements, as well as thenumber of people in the sixties, seventies, and eighties plus
groups. In addition, measurements taken by the DEXA method
for the 53 subjects are shown by age group in a scatter plot;
Figure 1 shows total BMD, and Figure 2 shows lumbar spine
BMD. The total BMD of healthy women as shown by Morita
et al.21) has an average value with ±1.5 SD, and the healthy
lumbar spine BMD reference value as determined by the Japan
Osteoporosis Society22) also has a ±1.5 SD range. Most of thesubjects were appropriately distributed within the ±1.5 SD
value (statistics on approximately 74% are included).
Data related to correlations between both total BMD andlumbar spine BMD, and BUA are shown in Table 2 and divided
into the sixties, seventies, and eighties plus age groups.
Although total BMD and lumbar spine BMD’s relationship toAge (Years)
Height (cm)Body weight (kg)BMI (kg/m2)
Total BMD (g/cm2)
Lumber spine BMD(g/cm2)
BUA (dB/MHz)
postmenoposal years (Years)

全Total身 骨
密 度(g／ｃ㎡）
BMD(g/cm2)

n
20
20
20
20
20
20
17
20

2

1.4

Sixties
Mean ± SD
64.6 ± 2.7
150.3 ± 4.3
52.2 ± 6.8
23.4 ± 2.3
0.814 ± 0.075
0.800 ± 0.119
57.6 ± 5.0
16.3 ± 7.8

Lumbar spine BMD (g/ cm )腰椎（L2-L4）骨密度(g／ｃ㎡）

Table 1. The Physical Characteristics and measurements

1.3
1.2
1.1
1
0.9
0.8
0.7
0.6

Seventies
Mean ± SD
73.3 ± 2.6
149.5 ± 4.6
49.0 ± 7.8
22.0 ± 3.5
0.743 ± 0.079
0.736 ± 0.166
54.4 ± 4.7
25.1 ± 4.0
1.4

n
24
24
24
24
24
24
17
24

Eighties Plus
Mean ± SD
83.2 ± 4.3
149.4 ± 3.9
47.0 ± 9.4
20.9 ± 3.5
0.763 ± 0.078
0.723 ± 0.093
53.6 ± 3.7
34.5 ± 7.1

n
9
9
9
9
9
9
6
8

40

50

80

1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4

0.5
20

30

40

50

60
70
年齢（歳）

80

90

20

100

30

60
70
年齢（歳）

90

100

Age (Years)

Age (Years)

腰椎（L2-L4）骨密度

全身骨密度

Figure 2. Age group in a scatter plot; lumbar spine BMD

Figure 1. Age group in a scatter plot; total BMD

Figure 1. Age group in a scatter plot; total BMD

Figure 2. Age group in a scatter plot; lumbar spine BMD

al. 21) has an average value with ±1.5 SD

spine BMD reference value as determined by the Japan Osteoporosis Society 22) also
has a ±1.5 SD range. Most of the subjects were appropriately distributed within the

Measurements taken by the DEXA method for the 53 subjects are shown by age
Measurements taken by the DEXA method for the 53 subjects are shown by age
group in a scatter plot; lumbar spine BMD. The lumbar spine BMD of the healthygroup in a scatter plot; total BMD. The total BMD of healthy women as shown
taken
by the DEXA
methodgroup
lumbarspine BMD reference
value
as determined
the53
Japan
Osteoporosis
Measurements
taken by the
DEXA
method forbythe
subjects
are shown by age groupan averagevalue with
±1.5 forSD the 53 subjects are shown by age
by Measurements
Morita et al.21) has
22)
Societyalso has a ±1.5 SD range. Most of the subjects were appropriately
in a scatter plot; total BMD. The total BMD of healthy women as shown by Morita
etin a scatter
plot;
distributed
withinthelumbar±1.5 SDspine
valueBMD. The lumbar spine BMD of the healthy lumbar

12±1.5 SD value

This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2015

BUA showed significant correlations in the sixties age group(r = 0.712, n = 17, p < 0.001; r = 0.658, n = 17, p < 0.01), in theseventies age group, there was only a significant correlation
with total BMD (r = 0.694, n = 17, p < 0.01). In the eighties
plus age group, there was no significant correlation regarding
any values. In all age groups, total BMD and lumbar spine BMD
showed significant correlation with BUA (r = 0.714; n = 40,
p < 0.001; r = 0.450; n = 40, p < 0.01). Correlation between
subjects’ physical characteristics and BMD and BUA are shownin Table 3.
In examining how the subjects’ body weight related to
BMD and BUA, the sixties group showed a significant positive
correlation between body weight and total BMD, lumbar spine
BMD, and BUA (r = 0.523, n = 20, p < 0.05; r = 0.641, n = 20, p <0.01; r = 0.617, n = 17, p < 0.01). The seventies group showeda significant positive correlation between body weight andtotal BMD as well as BUA (r = 0.647, n = 24, p < 0.001; r =0.712, n = 17, p < 0.01). In addition, lumbar spine BMD andbody weight showed a positive correlation and a 10% lower
risk of reduced density (r = 0.399, n = 24, p < 0.1). In theeighties plus group, however, no significant correlation wasseen, and there was a negative correlation between BUA andbody weight (r = –0.508, n = 6). These data correspond to thecorrelation between body weight and total BMD in Figure 3.
In examining subjects’ postmenopausal years with relation
to BMD and BUA, the sixties group showed a significant
negative correlation with total BMD and lumbar spine BMD(r = –0.496, n = 20, p < 0.05; r = –0.489, n = 20, p < 0.05), but

the seventies and eighties plus groups showed no significant
correlation. The correlations between postmenopausal years
and total BMD are shown in Figure 4.
B. Correlation between Nutrient Uptake and BMD and BUA

Table 4 shows the average values and standard deviationsof each type of nutrient uptake for each age group. Whether
each individual’s nutrient uptake met the recommended
amount (on the low end of healthy ranges, according to theJapanese Nutritional Requirements 6th Edition Revised11),)of the average uptake values based on subjects of the samegender and age is displayed in the table. In addition, Table 5shows the correlations between nutrition uptake and total
BMD, lumbar spine BMD, and BUA.
There was no significant correlation between energy uptake
and BMD or BUA in the sixties and seventies groups; however,in the eighties plus group, there was a positive trend between
total BMD and energy uptake that showed a 10% or lower risk
rate of reduced density (r = 0.610, n = 9, p < 0.1).
The sixties and seventies groups showed no significant
correlation between protein uptake and BMD or BUA;
however, the eighties plus group showed a significant positive
correlation between protein uptake and total BMD (r = 0.740,
n = 9, p < 0.05), and lumbar spine BMD showed a positive
correlation with protein uptake. This correlation suggested
a 10% or lower risk rate of reduced density (r = 0.624, n =9, p < 0.1). Figure 5 shows the correlation between subjects’

Table 2. The Total BMD and Lumber Spine BMD’s
Relationship to BUA

SixtiesSeventies
Eighties Plus
Total

BUA

Total BMD
(g/cm2)0.712 ***
0.694 **
0.616
0.714 ***

n

17
17
6
40

* p<0.05 ** p<0.01 *** p<0.001

Lumber Spine
BMD (g/cm2)
0.658 **
0.215
0.506
0.450 **

Table 3. The physical Characteristics and BMD and BUA

Total BMD (g/cm2)
SixtiesSeventies Eighties
plus(n=20)(n=24)(n=9)

Body Weight (kg)
Postmenoposal Years (Years)

0.523*-0.496** p<0.05** p<0.01*** p<0.001

0.647***-0.233

0.496
0.147

全 身 骨 密 度（g/c㎡）(g/cm2)The seventies
ｙ＝0.065ｘ+0.4235
ｒ＝0.647, n=24, p<0.001

Total BMD (g/cm2)

0.641**-0.489*0.399-0.252

Sixties(n=17)

0.418
0.427

BUA (dB/MHz)
Seventies(n=17)

0.617**-0.2670.712**-0.287

Total BMD

The sixties
ｙ＝0.0058ｘ+0.5099
ｒ＝0.523, n=20, p<0.05

The sixties
The seventies
The eighties and older

Eightiesplus(n=6)-0.5080.728

The eighties and older

1

The eighties and older
ｙ＝0.0041ｘ+0.5698
ｒ＝0.496, n=9◆●△

Lumber Spine BMD (g/cm2)
Sixties Seventies Eighties
plus(n=20)(n=24)(n=9)

ｙ＝0.0015ｘ+0.7227
80代以上
ｒ＝0.147, n=9
y = 0.0015x + 0.7227
ｒ = 0.147, n=9

0.9

The seventies
ｙ＝-0.0046ｘ+0.8584
70代n=24
ｒ＝-0.233,

0.8

y = -0.002x + 0.7958
ｒThe= -0.119,
n=25
sixties0.7

60代 n=20, p<0.05
ｒ＝-0.496,
y = -0.0048x + 0.8919
ｒ = -0.496, n=20, p<0.05

ｙ＝-0.0048ｘ+0.8919

◆
●
△

0.6

The60代全身骨密度
sixties
The seventies
70代全身骨密度The eighties and older

80代以上全身骨密度0.5
0Body weight (kg )

10

20

30

40

50

閉経後年数(年）
Postmenoposal
years (Years)

Figure 3. The correlation between body weight and total

Figure 4. The correlation between Postmenoposal years andFigure 4. The correlation between Postmenoposal years and total BMD
total BMD

BMD between body weight and total BMD
Figure 3. The correlation

13
This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2015

total BMD and protein uptake.
The average value of lipid uptake (as a percentage of
total energy) was 23.8% for the sixties group, 26.3% for theseventies group, and 29.8% for the eighties plus group; theJapanese Nutritional Requirements 6th Edition Revised11)
recommends an upper limit of 25%, which both the seventies
and eighties plus groups exceeded. No significant correlation
between lipid and carbohydrate uptake and BMD or BUA wasfound in any age group.
The sixties and seventies groups showed no significant
correlation between calcium uptake and BMD or BUA. In
contrast, the eighties plus group showed significant positive

correlation between calcium uptake and lumbar spine BMD(r = 0.685, n = 9, p < 0.05). Figure 6 shows the correlation
between subjects’ calcium uptake and lumbar spine BMD.
The sixties and seventies groups showed no significant
correlation between phosphorus uptake and BMD or BUA;
however, the eighties plus group showed a trend of a 10%
or lower risk rate in regards to total BMD with increased
phosphorous uptake (r = 0.604, n = 9, p < 0.1).
The sixties and seventies groups showed no significant
correlation between iron uptake and BMD or BUA, but in theeighties plus group, there was a significant positive correlation
between iron uptake and BUA (r = 0.893, n = 6, p < 0.05).

Table 4. Nutrient uptake for Age Group
Sixties
Mean ± SD
1630 ± 292
65.6 ± 10.9
43.2 ± 12.8240 ± 46.0
582 ± 177*958 ± 192
10.1 ± 2.52785 ± 1921
0.90 ± 0.20
1.20 ± 0.28
107.2 ± 46.7

Energy uptake (kcal / day)Total protein uptake (g / day)Total lipid uptake (g / day)
Carbohydrate uptake (g / day)Calcium uptake (mg / day)Phosphorus uptake (mg / day)Iron uptake (mg / day)
Vitamin A uptake (IU / day)
Vitamin B1 uptake (mg / day)
Vitamin B2 uptake (mg / day)
Vitamin C uptake (mg / day)Seventies
Mean ± SD
1560 ± 420
62.1 ± 1545.6 ± 17.5
220 ± 58569 ± 198*
913 ± 235
9.7 ± 2.4*
2730 ± 2070
0.84 ± 0.24
1.13 ± 0.34
100.6 ± 39.2

n
20
20
20
20
20
20
20
20
20
20
20

Eighties Plus
Mean ± SD
1381 ± 316
58.4 ± 10.6
43.1 ± 12.4
189 ± 68568 ± 91*902 ± 117
9.9 ± 1.9*3036 ± 1299
0.85 ± 0.17
1.19 ± 0.22
102.4 ± 45.7

n
24
24
24
24
24
24
24
24
24
24
24

*On the low of healthy ranges, according to the Japanese Nutrirional Requirements 6th Edition Revised

n
9
9
9
9
9
9
9
9
9
9
9

Table 5. Correlation between Nutrient Uptake and BMD and BUA
Total BMD (g/cm2)
Sixties Seventies Eighties
plus(n=20)(n=24)(n=9)

Energy uptake (kcal / day)Total protein uptake (g / day)Total lipid uptake (g / day)
Carbohydrate uptake (g / day)Calcium uptake (mg / day)Phosphorus uptake (mg / day)Iron uptake (mg / day)
Vitamin A uptake (IU / day)
Vitamin B1 uptake (mg / day)
Vitamin B2 uptake (mg / day)
Vitamin C uptake (mg / day)-0.0250.030-0.067-0.069
0.119
0.205
0.291
-0.069
0.396
0.186
0.237

* p<0.05** p<0.01*** p<0.001

0.101
0.189
0.123
0.018
0.036
0.094
0.030
0.395
-0.0480.358-0.1030.610
0.740*
0.147
0.460
0.618
0.604
0.550
0.231
0.720*
0.491
0.459-0.1200.167-0.135-0.148-0.0740.076
0.155-0.046
0.235
0.022
0.145

The
eighties and older
80代以上
ｙ＝0.0054ｘ+0.4465
y = 0.0054x+ 0.4465
ｒ＝0.740,p<0.05ｒ = 0.740,
n=9,n=9,p<0.05

0.9

The seventies
The seventies

ｙ＝0.001ｘ+0.6816
70代
ｙ＝0.001ｘ+0.6816
ｙ = ｒ＝0.189,
0.0009x +n=24
0.6901ｒ = 0.171, ,n=25
ｒ＝0.189
n=24

0.8
,

The sixties
ｙ＝0.0021ｘ+0.6739
60代
ｒ＝0.302, n=20

y = 0.0021x + 0.6739
ｒ = 0.290, n=21

0.7

◆ The
The
sixties and older◆
eighties
60代全身骨密度● The
The seventies
seventies●
70代全身骨密度△ The
Theeighties and older△
sixties

0.6

0.132
0.143
0.204
0.045
0.006
0.087
0.136
0.377
0.187
0.204
0.171

0.472
0.624
-0.0750.428
0.685*
0.591
0.310
0.290
0.644
0.436
0.259

BUA (dB/MHz)
Sixties Seventies Eighties
plus(n=20)(n=24)(n=9)-0.0490.481
0.056-0.249-0.1840.288-0.029-0.3880.171
0.096-0.0520.023-0.0490.110-0.069-0.090-0.181-0.2270.031-0.0820.247-0.153

1.2

Lumber(g/cm2)
腰 椎 spine
骨 密BMD度（g/c㎡）

1

2
Total
BMD
(g/cm
)
全 身
骨 密
度（g/c㎡）

Lumber Spine BMD (g/cm2)
Sixties Seventies Eighties
plus(n=20)(n=24)(n=9)

80代以上全身骨密度

80代以上
The eighties
and older-4-4ｘ+0.3267
ｙ＝7×10y = 7×10
x + 0.3267
ｒ＝0.685,
ｒ = 0.685,n=9,
n=9,p<0.05
p<0.05

1.1

The seventies
70代
ｙ＝7×10-8ｘ+0.7328-5
y = -1×10 x + 0.7499
ｒ＝0.006, n=24

1
0.9

ｒ = -0.013, n=25

The sixties
60代
ｙ＝-5×10-5ｘ+0.829-5x + 0.8354
y = -7×10
ｒ＝-0.074,
n=20

0.8

ｒ = -0.099, n=21

0.7

◆ The sixties◆ 60代腰椎（L2-L4）骨密度
The eighties and older● The seventies● The seventies△ 70代腰椎（L2-L4）骨密度
The eighties and older△ The sixties

0.6
0.5

0.5
30

40

50

60

70

80

90

100

0.419
0.181
0.079
0.424
0.145
0.291
0.893
-0.045
0.245
0.175
0.432

80代以上腰椎（L2-L4）骨密度0.4

Total 蛋白摂取量(ｇ/日）
protein uptake (g / day)50

Figure5. The correlation between total protein uptake andFigure 5. The correlation between total protein uptake and total BMD
total BMD

250

450

650

850

1050

1250

1450

カルシウム摂取量(ｇ/日）
Calcium
uptake (mg / day)Figure 6. The correlation between calcium uptake andlumbar spine BMD

Figure 6. The correlation between calcium uptake and lumbar spine BMD

14This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 201575

全 身 骨 密 度（g/c㎡）

70(g/cm2)The seventies
70代
ｙ＝-0.4121ｘ+58.263
yｒ＝-0.227,= -0.4423x+ 58.623
n=1765

ｒ = -0.248, n=25

60

The sixties
ｙ＝-0.0547ｘ+58.459
60代
n=17
yｒ＝-0.029,= -0.0377x+ 57.982

55

Total BMD

BUA
B (dB/MHz)U A（dB/MHz）

1

The eighties
and older
80代以上
yｙ＝1.5055ｘ+38.546= 1.5055x + 38.546
n=6, p<0.05
p<0.05ｒｒ＝0.893,= 0.893, n=6,

ｒ = -0.019, n=21
50

◆ The sixties
60代BUA◆● Theeightiesand olderThe
seventies
70代BUA●△ Theseventies
The
eighties and older△ The sixties

45

The eighties
and older
80代以上
y ｙ＝0.3238ｘ+0.4881= 0.3238x + 0.4881
ｒ＝0.720, n=9, p<0.05
ｒ = 0.720 , n=9, p<0.05

0.9
The seventies
70代
y ｙ＝0.016ｘ+0.7566= -0.022x + 0.7636, n=24ｒ =ｒ＝-0.048-0.067, n=25

0.8

The 60代
sixtiesy ｙ＝0.1481ｘ+0.6806= 0.1423x + 0.6815
n=20,p<0.1
p<0.1
ｒ =ｒ＝0.396,
0.370, n=21,

0.7

The
sixties
60代全身骨密度◆◆ Theeightiesand olderThe
seventies●● Theseventies
70代全身骨密度△Theeighties and older△ The sixties

0.6

80代BUA

80代以上全身骨密度

0.5

40
4

6

8

10

12

14

16

18

0.4

Iron鉄摂取量(ｇ/日）
uptake (mg / day)

0.6

0.8

1

1.2

1.4

1.6

1.8

ビタミンB
Vitamin1摂取量(ｇ/日）
B1 uptake (mg / day)Figure 7. The correlation between iron uptake and BUA

Figure8. The correlation between vitamin B1 uptake andFigure 8. The correlation between vitamin B1 uptake and total BMD
total BMD

Figure 7 shows the correlation between subjects’ iron uptake
and BUA.
The sixties and eighties plus groups showed no significant
correlation between vitamin A uptake and BMD and BUA, but
in the seventies group, there was a noticeably positive trend of
a 10% or lower risk rate of decreased total and lumbar BMD
as vitamin A uptake increased (r = 0.395, n = 24, p < 0.1; r =0.377, n = 24, p < 0.1).
The sixties group showed a positive correlation between
B1 uptake and a 10% or lower risk of total BMD decrease(r = 0.396, n = 20, p < 0.1). The seventies group showed nosignificant correlation, but the eighties plus group showed asignificant positive correlation with total BMD (r = 0.720, n= 9, p < 0.05), as well as a trend of a 10% or lower risk rateof decreased BMD with regards to lumbar spine BMD (r =0.644, n = 9, p < 0.1). Figure 8 shows the correlation between
subjects’ vitamin B1 uptake and total BMD.
The seventies group showed a positive correlation between
increased B2 vitamin uptake and a 10% or lower risk rate ofdecreased total BMD (r = 0.358, n = 24, p < 0.1).
Regardless of age, there seemed to be no significant
correlation between vitamin C uptake and BMD or BUA.

Morita et al.21) reported that the average BMD value of
healthy women ranged within ±1.5 SD of the average, andthe Japan Osteoporosis Society22) defines healthy lumbar
spine BMD values as within ±1.5 SD of the average. Most of
the subjects’ values were distributed within the ±1.5 SD value(statistics on approximately 74% were included). Therefore,
the subjects of this study were considered representative ofJapanese postmenopausal women.
The sixties group showed a significant correlation between
total and lumbar spine BMD and BUA, the seventies group
showed a significant correlation only between total BMD
and BUA, and the eighties group showed no significant
correlations between BMD, BUA, and physical characteristics.
Of the measured values for various bone mineral densities,
the lumbar spine BMD as determined by the DEXA method iscurrently used as a reference value for analyzing osteoporosis
and quantifying bone mass decrease. Lumbar measurementin the elderly can sometimes be problematic, however,and result in an overestimation of bone mass as a result of
degenerative spondylosis or aortic calcification. As a result,
it is necessary to measure regions other than the lumbar
region in the elderly22). In addition, since BMD has a greatamount of site specificity, measuring two or more locations
is generally desirable when using BMD to determine bonemass. In order to properly guard against a hip fracture, itis necessary to evaluate the femoral neck’s BMD; however,the structure of the femur is complex, as it is a primarily
cancellous, load-bearing bone. The calcaneus is often used
for evaluation purposes, since involutional changes in othersites, such as the lumbar spine, are small, and the calcaneus’
BMD is known to strongly correlate with risk of femoral neckfractures and vertebral compression fractures19). This study
showed a significant correlation for all ages, although, when
accounting for aging, there was a divergence between BUA andtotal BMD and lumbar spine BMD. Although it would be usefulfor predicting fractures to measure each bone’s composition,
the load it bears, and its unique metabolisms, such detailed
evaluation is impossible. Instead, evaluations based on eachbones’ already recorded characteristics are required. Still,since few Japanese have used an ultrasound bone imagining
scanner (UBIS) to determine these characteristics, further
studies on interregional relationships are necessary.
To clarify body weight’s relation to BMD and BUA, Huang etal.9) performed a follow-up study on Caucasian women (45-77
years old) who had experienced a femoral neck fracture. They
found that as body weight and body fat percentage decreased,
the frequency of femoral neck fractures increased. As thecalcaneus is a load-bearing bone with similar composition to

Figure 7. The correlation between iron uptake and BUA

IV. Considerations

The purposes of this study were to elucidate factors besides
aging that were related to BMD in postmenopausal women andto discover possible nursing interventions to help the elderly
maintain BMD. Accordingly, 53 postmenopausal women’s(61-92 years old) BMD and/or BUA was analyzed by age groupand body region in order to reveal possible correlations withbody weight, postmenopausal years, and nutritional uptake.
The results showed a significant correlation between total
BMD and BUA and body weight and postmenopausal years,
but not nutritional uptake for women in their sixties; forwomen in their seventies, there was a significant correlation
between body weight and total BMD and BUA, but not between
postmenopausal years or nutritional uptake; and for womenin their eighties, a significant correlation was found between
total BMD/BUA and nutrient uptake, but not postmenopausal
years or body weight. Each age group’s BMD was affected bydifferent factors, indicating the possibility of improving BMD
through nursing interventions and improved nutrient uptake
even for women 75 years and older.
A. Correlation between the Subjects’ Physical Characteristics
and BMD and/or BUA

15This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2015

the femoral neck, it reflects the BMD of the femoral neck20).
The calcaneus is 95% cancellous bone, readily giving a sense of
the bone’s metabolism. When remodeling the bone, variations
in muscle strength and gravity exerted on the skeleton
need to be taken into account. In this study, the calcaneus
showed a significant positive correlation with BMD in thesixties and seventies groups, except for the seventies group’s
lumbar spine BMD. In the eighties plus group, however, bodyweight and BUA showed a negative correlation coefficient. In
other words, as body mass increased, bone mass decreased.
Accordingly, maintaining bone mass in women older than 80
is difficult, as bone mass decreases in general and the lifelong
effects of load and mechanical stress accumulate.
Additionally, according to Okano et al.7) and Iki et al.8),
women’s BMD decreases rapidly when the menstrual cycle
starts to become irregular (menopause). According to ourstudy, although the sixties and seventies groups’ total BMD,
lumbar spine BMD, and BUA appeared to be affected bypostmenopausal years and body weight, the eighties plus
group was not affected by those factors.
To classify involutional osteoporosis, aging appeared to be
the primary factor affecting BMD and BUA in people older
than years4). Accordingly, in this study, the effects of bodyweight and postmenopausal years on total BMD, lumbar spine
BMD, and BUA varied by age group. The sixties group wasaffected by both postmenopausal years and body weight; theseventies group was not affected by postmenopausal years,
and only certain regions were affected by body weight; andthe eighties plus group was not affected by postmenopausal
years. This means that until women surpass approximately
65 years of age, postmenopausal osteoporosis has diagnostic
criteria similar to involutional osteoporosis4).

through urination. The extent of this effect differed basedon what other foods were consumed. It is also known thata low-protein state reduces bone mass11). The present study
also showed that increasing protein uptake in the eighties
plus group had a significant positive correlation with BMD,
reinforcing the importance of avoiding a low-protein state.
According to Yukawa et al.10) and Shono et al.13), there isa positive correlation between BMD and lipid uptake. In
the results of this study, however, BMD and BUA showed nosignificant correlation with lipid uptake or carbohydrate
uptake. Subjects of this study in the seventies and eighties
plus age groups, according to the recommended values ofJapanese Nutritional Requirements 6th Edition Revised11),
had high total lipid uptake percentages and low protein
and carbohydrate uptake values. Due to the subjects’ poorly
balanced diets, it is possible that they were not effectively
using lipids to maintain bone mass. Further study to clarify
the effects of the simultaneous ingestion of different nutrientsis necessary.
The calcium uptake for each age group (sixties, seventies,
and eighties plus) was 560-580 mg per day, which is less than
the required amount of 600 mg per day. According to a study
on fractures and calcium uptake by Fujiwara et al.16), subjects
who drank milk almost every day reduced their risk of femoral
neck fracture to about half that of subjects who drank milk
once a week or less. In this study, only the eighties plus group
showed a significant correlation with lumbar spine BMD andcalcium uptake. Calcium metabolism in the elderly can easily
become negative (excretion exceeding absorption) because
metabolism changes with age. Less calcium is absorbed as
uptake simply decreases, less active vitamin D is present in
the diet, and the lower intestine absorbs less calcium, causing
a relative increase in calcium absorption from the bones.
Calcium metabolism involves many components, including
hormone influence, and it cannot be quantified simply by
dietary uptake of calcium. If phosphorus and calorie uptake
are small, calcium may be inefficiently absorbed. In theeighties plus group, in particular, further study of simultaneous
ingestion of various foods should be conducted. In this study,
all groups failed to consume the recommended daily amountof calcium; calcium is one of the few nutritional benchmarksthat Japanese citizens do not often fulfill, and each age groupneeds a carefully controlled uptake.
According to Dainen et al.13), iron uptake does not affect bonemetabolism. The present study showed a positive correlation
between BUA and iron uptake for the eighties plus group;
however, the eighties plus group’s BUA had little correlation
with other bone mineral densities. In the future, larger studies
should be conducted to determine true significance.
Yamagami et al.17), found in their study elderly people living
alone did not ingest enough of the necessary vitamins without
taking vitamin supplements. In the present study, no averagevitamin uptake values failed to meet the recommended values,
suggesting that the subjects in this study did indeed have goodnutritional status. This study shows that, even when living
alone, proper vitamin uptake can be maintained as long as
the necessary facilities and services are available, and it showsthat nutritional habits necessary for maintaining bone masscan be improved.
Vitamin B1 is necessary for normal function of the central
nervous system and peripheral nerves and is thought toactivate mechanical stress. In this study, vitamin B1 uptake
was shown to have a positive correlation with BMD in the

B. Correlation between Nutrient Uptake and BMD and BUA

To clarify the relationship between BMD and nutrition,
Huang et al.9) performed a follow-up study on Caucasian
women (45-77 years old) who had experienced a femoral neckfracture. The authors found that poor nutritional status or low
levels of blood albumin concentration increased the risk of afemoral neck fracture. Yukawa et al.10) also found, in a longterm longitudinal study of Japanese women up to 79 years old,that certain nutrients and food, when regularly consumed ina balanced diet as a variety of foodstuffs, improved the body’s
overall nutritional status, which helped maintain bone mass
and BMD. In this study, the eighties plus group showed acorrelation between nutritional uptake and total BMD, lumbar
spine BMD, and BUA, similar to the results found in otherstudies focused on women in their seventies. In those studies,a positive correlation was seen between nutritional status
and overall BMD. To date, however, no significant correlation
between nutrition and BMD has been seen in women younger
than 70. Since women can experience unpleasant symptoms
in their early postmenopausal years until their seventies, it isthought nutrition may be unable to compensate for BMD loss
between menopause and the seventh decade. This study also
did not compare the different nutrient uptakes to each other,possibly overlooking individual nutrient contributions.
Excessive protein uptake promotes the release of calcium
from bones, increasing calcium excretion through urination.
This is thought to result in a decrease in bone mass11); however,in a report by Apell et al.12), eating fruits and vegetables andsodium bicarbonate reduced the amount of calcium excreted
16This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.

Yearbook on Journal of the Japan Society of Nursing Research 2015

eighties plus group and aided in bone mass maintenance as aresult of mechanical stress.
To contextualize the results of this study, we first examinedprior studies investigating total BMD, lumbar spine BMD, and
BUA’s correlation with body weight and postmenopausal
years. Those results showed significant correlations between
these factors on women in their sixties and seventies, but nocorrelation amongst women older than 80. This meant thatsome external factors must be important in women who wereeighty or older. Accordingly, we then examined total BMD,
lumbar spine BMD, and BUA’s relation to nutrient intake. We
saw no correlation between type of nutrient intake and total
BMD, lumbar spine BMD, or BUA for women in their sixties
and seventies; however, the total BMD, lumbar spine BMD, and
BUA’s were significantly positively correlated with protein,calcium, iron, and vitamin B1 intake in the eighty plus group.
Nutrient uptake should certainly be considered a factor inmaintaining BMD.
Overall, the BMD was affected in the following manner
across age groups: women in their sixties were affectedby postmenopausal years and body weight, those in theirseventies were affected by their body weight, and those who
were 80 years and older were affected by their nutritional
uptake.
The results of our study did not agree with the preexisting
literature based on nutritional surveys reporting nutrient
relationship with BMD and BUA for women in their sixties andseventies. This may be because each nutrient uptake analysis
only included its own, simple correlation with BMD and BUA,
and correlations between different nutrient intakes could
not be adequately considered because of the low number ofsubjects involved. In the future, to identify truly significant
nutrients, the relationships between nutrients should beanalyzed. In order to do this, larger studies that identify
factors by multiple regression analysis should be conducted.
Maintaining BMD can protect against fractures caused byosteoporosis, and it is a known prognostic factor. It is hopedthat the results of this study will be useful in maintaining thehealth of the elderly.

we would like to thank the many nursing home residents alongwith the students from the A City University for the Elderly.
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V. Conclusion

In this study, we examined factors that affect total BMD,
lumbar spine BMD, and BUA in postmenopausal women (ages60-92) by age group. Women in their sixties showed a positive
correlation between body weight and total BMD, lumbar spine
BMD, and BUA; women in their seventies showed a positive
correlation between body weight and total BMD and BUA. Only
women in their sixties showed a negative correlation between
postmenopausal years and total BMD and lumbar spine
BMD. With regards to nutrient uptake, a positive correlation
between total BMD and protein and vitamin B1 uptake, lumbar
spine BMD and calcium uptake, and BUA and iron uptake wasonly seen in the eighties plus group. Therefore, we believe thateven for women eighty years and older, nursing interventions
to help maintain bone mass are possible.
Acknowledgements

We appreciate the help and cooperation we received fromthe great number of people who aided us when performing
this study and finishing the manuscript. For their willing
cooperation in the research with measurements and surveys,
17

This paper was published at “the Japan Society of Nursing Research” Vol.25 No.5 in 2002.