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JOURNAL OF SCIENCE, Hue University, N0 61, 2010
RISK FACTORS OF PRE-DIABETES IN ADULTS AGED 45 YEARS
AND OLDER IN CAU NGANG DISTRICT, TRA VINH PROVINCE
Cao My Phuong
Tra Vinh General Hospital
Dinh Thanh Hue, Nguyen Hai Thu
College of Medicine and Pharmacy, Hue University
SUMMARY
A case - control study in the population aged 45 years and older was conducted in Cau
Ngang district, Tra vinh province. The case group included 100 pre-diabetic subjects, and the
control group comprised of 200 non pre-diabetic subjects, who were randomly selected from a
previous cross sectional study, matched in 7 risk factors including age, sex, ethnic group, place
of living, standard of living, having a family member with diabetes, and giving birth to a baby
weighing more than 4 kg. The result showed that risk factors of pre-diabetic patients included:
overweight/obesity, high waist circumference, high body fat percentage, sweet drinking – eating
habit, daily excessive sugar consumption, and daily excessive fatty food intake.
Key words: Prediabetes, risk factors, obesity, waist circumference
1. Introduction
Pre-diabetes is a condition in which blood glucose levels are higher than normal,
but not high enough for a diagnosis of diabetes. Pre-diabetes has been defined by The
American Diabetes Association with the WHO’s agreement of having impaired fasting
glucose (fasting blood glucose levels between 100 and 125 mg/dl) or impaired glucose
tolerance (2 hour post-glucose load, plasma glucose levels between 140 and 199 mg/dl).
Impaired fasting glucose and impaired glucose tolerance may progress to type 2
diabetes mellitus. People with pre-diabetes are likely to develop type 2 diabetes within
10 years, unless they take steps to prevent or delay diabetes. Moreover, diabetes is
associated with aging. However, recently, diabetes mellitus has tended to happen in the
younger people, especially people from the age of 45 years.
Most of researches have demonstrated that risk factors of hyperglycemia
included overweight/obesity, hypertension, lack of physical activities, malnutrition,
having a family background of diabetes and giving birth to a baby weighting more than
4 kg…The complications of diabetes mellitus can occur in the stage of pre-diabetes and
pre-diabetic patients are also at increased risk for developing cardiovascular disease. For
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a long period of time before diabetes is detected, the degree of hyperglycemia above
sufficient threshold can cause pathologic and functional changes in various target tissues
but without clinical symptoms.
Pre-diabetes is becoming more common in the United States. The U.S.
Department of Health and Human Services estimates that about a quarter of U.S. adults
aged 20 years or older—or 57 million people—had pre-diabetes in 2007.
A cross – sectional study in Cau Ngang district, Tra Vinh province in December
2009 has pointed out that prevalence of pre-diabetes in participants aged 45 years and
older was 19.5% which seemed slightly high. This research was designed to explore
which risk factors have contributed to this high percentage of pre-diabetes.
2. Method
2.1. Subjects
The study sample consisted of individuals aged of 45 or older, who were
permanent residents living in Cau Ngang district, Tra Vinh province.
2.2. Research method: A case – control study
- Sample: using the formula of Schlesselman6:
2
3
2
33βα
pf
qpf1fZu12uZ
n
With:
1ORf1
OR
1f
2
1
u;
1ORf1
fOR
p3
; 33 p1q
;
Predicted: f = 0,30; OR = 2,5; accepted: = 0,05; = 0,10; → n
100.
In December 2009, we carried out a cross sectional study in a random sample
selected from a population of people aged 45 and older in Cau Ngang district, Tra Vinh
province, with a sample size of n = 1226. There were 239 pre – diabetic subjects and
115 diabetic subjects found. The rest included 872 subjects with normal blood glucose
levels. Based on that result, we selected participants for this study.
+ The case group: of the 239 pre-diabetic subjects, 100 individuals were selected
for the case group using a simple random method
+ The control group: of the 872 subjects with normal blood glucose levels, 200
respondents were chosen using a simple random method
One pre-diabetic subject with two control subjects were matched in age, sex,
ethnic group, place of living, standard of living, having a family member with diabetes,
and giving birth to a baby weigh more than 4 kg.
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- Data collection:
A face to face interview method, using a prepared questionnaire was used to
collect necessary information
Interviewers were health professionals of Phu Yen hospital and Phu Yen Medical
College.
- Data analysis: Using Epi-info version 3.5.1 (2008).
Data is presented in the 2x 2 table for each related factor:
Case Control
Expose A C m1
Non-expose B D m2
n1 n2 n
From the table, the necessary results are calculated. Using 2 of Yates, p = 0.05.
3. Results
3.1. Factors related to present health
Risk Factors Case
group Contro
l group
OR
(95% CI) p
Hypertension
(mmHg) ( BSP≥
140 and/or
BDP≥90)
Yes
No
50
50
90
110
1.2
(0.8 – 2.0) > 0.05
BMI ≥ 23
< 23
38
62
50
146
1.8
(1.1– 3.0) < 0.01
WC (Waist
circumferences)
cm
-Male≥ 90,
Female≥80
- Male
<90,
Female<80
66
34
101
99
1.9
(1.2 – 3.1) < 0.01
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Body fat
percentage Index
(%)
- Male≥
20,
Female≥30
- Male<
20,
Female<30
74
26
109
91
2.4
(1.4 – 4.0) < 0.001
Visceral fat index
(%)
≥ 10
< 10
15
85
24
171
1.3
(0.6 – 2.5) > 0.05
3.2. Factors related to health behavior
Factors Case
group Control
group
OR
(95% CI) p
Smoking Yes
No
23
77
34
161
1.4
(0.8 – 2.6) > 0.05
Excessive
alcohol intake
Yes
No
19
81
30
165
1.3
(0.7 – 2.4) > 0.05
Sweet drinking -
eating habit
Yes
No
42
58
57
138
1.8
(1.1 – 2.9) < 0.05
Excessive sugar
consumption
Yes
No
34
66
34
160
2.4
(1.4 – 4.3) < 0.01
Excessive fatty
food intake
Yes
No
27
73
23
172
2.8
(1.5 – 5.1) < 0.01
Daily vegetable
intake
Yes
No
31
68
64
131
0.9
(0.6 – 1.6) > 0.05
Eating after 20h
habit
Yes
No
7
93
14
181
1.0
(0.4 – 2.5) > 0.05
Physical
activities
Yes
No
41
59
80
115
1.0
(0.6 – 1.6) > 0.05
Stress Yes
No
18
81
24
170
1.6
(0.8 – 3.0) > 0.05
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4. Discussions
4.1. Factors related to present health
Hypertension: Hypertension is able to occur in a metabolic syndrome.
Hypertension in a pre-diabetic state results from insulin resistance/hyperinsulinism and
is also considered as a risk factor of diabetes. Diabetes is normally associated with
hypertension. However, this research has not showed clearly that hypertension is related
to pre-diabetes (OR = 1.2, p > 0.05).
Waist circumferences: the results of this study demonstrated that there was a
correlation between a waist circumference index based on the Asian standard and pre-
diabetes. The group who had a high waist circumference index (male ≥ 90 cm, female ≥
80 cm) had approximately 1.9 times greater risk of pre-diabetes than the normal waist
circumference group (OR = 1.9; p < 0.01). Therefore, the high waist circumference is
clearly a risk factor of pre-diabetes in this community.
BMI: obesity is a traditional risk factor which may lead to diabetes, hypertension,
cardio-vascular diseases, gallbladder diseases, and several cancers. BMI is a measured
tool to diagnose obesity. Based on the Asian standard of BMI, this research also shows
that the group of overweight/obesity with high BMI (≥ 23 kg/m2) is probably at risk of
pre-diabetes 1.8 times higher than the group with low or normal BMI (OR= 1.8, p <
0.05).
Body fat percentages index: According to Nguyen Thi Kim Hung, individuals
who gained a high body fat percentage index had more than 2.5 times higher risk of
elevating blood glucose. The result of this study showed that body fat percentage index
related dramatically to pre-diabetes. Respondents with slightly high or high body fat
percentage index got more than 2.4 times higher risk of pre-diabetes than the other.
Hence, the body fat index was presented as one of the new risk factors of pre-diabetes
(OR = 2.4, p < 0.001).
Visceral fat index: the results of our study demonstrated that the group with high
visceral fat index did not have significantly higher risk of pre-diabetes than the one with
normal visceral fat index (OR = 1.3, p > 0,05).
4.2. Factors related to health behaviors
Smoking: smoking may increase insulin resistance and excite to produce stress
hormones – Both factors elevate the blood glucose level. In this research, smoking
status appeared to not be related to pre-diabetes (OR = 1.4, p > 0.05).
Excessive alcohol drinking habits: the excessive beer and alcohol intake for a
long time can cause hypertriglyceridemia and increase of blood glucose level in diabetes
patients. The study showed that, in this community, the excessive alcohol drinking habit