This study included 2,256 randomly selected participants from 6,769 people aged 40-69 years who visited health promotion and risk factor screening services in the Hospital for Children Eye ENT and Rehabilitation Services from June to December 2019. The mean age (SD) of the participants was 51.75 (8.47) years.
Prevalence of Obesity and overweight
The mean (SD) BMI was 25.29 (3.81) kg/m2 and 26.72 (4.44) kg/m2 among male and female participants, respectively. The mean BMI gradually decreased from younger age to older age groups in both males and females. The overall prevalence of obesity (BMI≥ 30 kg/m2) and overweight was 16.09% and 42.20%, respectively. However, female participants had a higher prevalence of obesity (21.4%) than male participants (9.6%) (p-value<0.001). The burden of obesity was higher among the younger age group in both genders.
The overall prevalence of overweight among males and females was 42.8% and 41.7%, respectively, which was not statistically significant (p-value = 0.6121). Younger age groups had a significantly higher prevalence (p-value <0.001) of overweight in both genders. Table 2 summarizes obesity and overweight according to gender and age groups. The odds ratio for being obese compared with females to males was 2.58 (95% CI: 2.01-3.31), and that of being overweight was 0.95 (95% CI: 0.0.81-1.13)
The overall prevalence of abdominal obesity by waist-to-height ratio was 32.76%, which is higher than obesity by BMI. Female participants had a higher prevalence (40.1%) than male participants (23.8%), and the difference was statistically significant (p-value < 0.001). The 40-54 age group had a significantly higher prevalence of abdominal obesity among female participants (37.59% vs 44.52%, p=0.0195) but not among male participants (23.96% vs 23.66%, p=0.974).
Table 1: Mean (SD) of different anthropometric measurements according to age and gender
|
Age group
|
Gender
|
|
40-54 years
|
55-69 years
|
p-value
|
Male
|
Female
|
p-value
|
|
Mean
|
SD
|
Mean
|
SD
|
Mean
|
SD
|
Mean
|
SD
|
SBP
|
118.46
|
14.96
|
122.77
|
16.49
|
<0.001
|
121.47
|
15.50
|
118.90
|
15.74
|
<0.001
|
DBP
|
79.21
|
10.74
|
79.39
|
10.25
|
0.69
|
79.98
|
10.67
|
78.69
|
10.43
|
<0.01
|
Weight (KG)
|
65.55
|
10.81
|
61.58
|
11.41
|
<0.001
|
67.41
|
11.15
|
61.32
|
10.48
|
<0.001
|
Height (CM)
|
157.60
|
8.84
|
155.47
|
9.15
|
<0.001
|
163.19
|
7.23
|
151.54
|
6.62
|
<0.001
|
WC (CM)
|
89.51
|
10.38
|
89.40
|
11.36
|
0.83
|
90.96
|
10.32
|
88.24
|
10.94
|
<0.001
|
WHtR
|
0.57
|
0.07
|
0.58
|
0.08
|
0.02
|
0.56
|
0.06
|
0.58
|
0.08
|
<0.001
|
BMI
|
26.41
|
4.08
|
25.50
|
4.41
|
<0.001
|
25.29
|
3.81
|
26.72
|
4.44
|
<0.001
|
High waist circumference was observed among 66.76% participants, whereas female participants had a very higher prevalence of high waist circumference (77.46%) and male participants (53.73%) (p<0.001). There was no significant difference between the age groups in both genders (in males; p=0.125, in females; p=0.807).
Table 2: BMI, WHtR and waist circumference classification according to age and sex
Characteristic
|
n
|
Body Mass Index (BMI)
|
Waist to Height Ratio (WHtR)
|
Waist Circumference (CM)
|
≥ 30.0 kg/m2
|
25.0 - 29.9 kg/m2
|
< 25.0 kg/m2
|
> 0.60
|
0.50 - 0.59
|
< 0.50
|
≥ cut off
|
< cut off
|
All
|
|
2,256
|
16.09
|
42.20
|
41.71
|
32.76
|
53.19
|
14.05
|
66.76
|
77.46
|
Male
|
All age
|
1,048
|
9.6
|
42.8
|
47.5
|
23.8
|
60.0
|
16.2
|
53.73
|
46.27
|
|
40-54
|
634
|
10.88
|
47.48
|
41.64
|
23.65
|
60.25
|
16.09
|
55.68
|
44.32
|
|
55-69
|
384
|
7.55
|
35.16
|
57.29
|
23.96
|
59.63
|
16.41
|
50.52
|
49.48
|
Female
|
All age
|
1,238
|
21.4
|
41.7
|
36.9
|
40.1
|
47.6
|
12.3
|
77.46
|
22.54
|
|
40-54
|
782
|
21.74
|
44.37
|
33.89
|
37.59
|
50.00
|
12.40
|
77.75
|
22.25
|
|
55-69
|
456
|
20.83
|
37.06
|
42.10
|
44.52
|
43.42
|
12.06
|
76.97
|
23.06
|
# cut off value of waist circumference for males is 90 cm and for females is 80 cm
Prevalence of Hypertension
The overall prevalence of hypertension and prehypertension was 40.67% and 36.77%, respectively. Male participants had a slightly higher prevalence of hypertension (42.72%)
Table 3: Hypertension, sociodemographic variables and risk factors
|
|
Pre HTN
n (%)
|
HTN
n (%)
|
Unadjusted Odds Ratio for HTN (95% CI)
|
Adjusted Odds ratio* for HTN (95% CI)
|
All
|
|
828 (36.77)
|
916 (40.67)
|
|
|
Sex
|
Female
|
434 (35.11)
|
482 (39.00)
|
1
|
1
|
Male
|
394 (38.78)
|
434 (42.72)
|
0.86 (0.88-1.01)
|
0.86(0.72-1.02)
|
Age group
|
40-54
|
544 (38.50)
|
514 (36.38)
|
1
|
1
|
55-69
|
284 (33.85)
|
402 (47.91)
|
1.61 (1.35-1.91)
|
1.61(1.35-1.91)
|
BMI
|
< 25 kg/m2
|
337 (35.93)
|
312 (33.26)
|
1
|
1
|
≥ 25 kg/m2
|
491 (37.37)
|
604 (45.97)
|
1.74 (1.43-2.03)
|
1.89 (1.58-2.26)
|
WHtR
|
< 0.5
|
93 (31.74)
|
83 (28.33)
|
1
|
1
|
≥ 0.5
|
735 (37.52)
|
833 (42.52)
|
1.87 (1.43-2.45)
|
1.92 (1.46-2.52)
|
WC# (CM)
|
< cutoff
|
281 (37.57)
|
235 (31.42)
|
1
|
1
|
≥ cutoff
|
547 (36.37)
|
681 (45.28)
|
1.81 (1.50-2.17)
|
2.02 (1.66-2.45)
|
Current Alcohol Drinker
|
no
|
785 (36.96)
|
853 (40.16)
|
1
|
1
|
yes
|
42 (33.33)
|
62 (49.21)
|
1.44 (1.01-2.07)
|
1.43(0.84-1.73)
|
Current Smoker
|
no
|
785 (37.17)
|
851 (40.29)
|
1
|
1
|
yes
|
42 (30.43)
|
64 (46.38)
|
1.28 (0.91-1.81)
|
1.21 (0.85-1.73)
|
# cut off value of waist circumference for males is 90 cm and for females is 80 cm
* Adjusted odds ratios of age and sex were adjusted for sociodemographic variables (age, sex). Odds ratios for risk factor variables were adjusted for age and sex variables.
than female participants (39.00%). Hypertension was found in higher prevalence among the age groups increased in both genders. Prehypertension was found in 38.50% and 33.85% of male and female participants, respectively. In comparison, 81.50% male and 74.11% female participants had either hypertension or prehypertension. Among 916 participants with hypertension, 57.4% did not know they had raised blood pressure before this study.
The age-adjusted odds ratio for being hypertensive for females compared to males was 0.85 (95% CI: 0.72-1.02), and the sex-adjusted odds ratio for being hypertensive was 1.61 (95% CI: 1.35-1.91) for the 55-69 age group compared to the 40-54 age group. Approximately half of the participants (49.21%) who were current alcohol drinkers had hypertension, and 33.33% had prehypertension. Similarly, 46.38% and 30.43% of current smokers had hypertension and prehypertension, respectively.
Obesity and Hypertension
The prevalence of hypertension among the participants with BMI≥25 kg/m2, WHtR≥0.5 and WC≥ cutoff values was 45.97%, 42.52% and 45.28%, respectively. A significantly higher prevalence of hypertension was found among participants with either overweight or obesity compared to participants with normal weight (P-value <0.001). Age- and sex-adjusted odds ratios for hypertension among high BMI, waist to height ratio and waist circumference were 1.74 (95% CI: 1.43-2.03), 1.87 (95% CI: 1.43-2.45) and 1.81 (95% CI: 1.50-2.17), respectively.
Table 4 shows the correlations between BMI, WC, WHtR, BP and age, including the level of significance. A strong positive correlation (P<0.01) was found between waist circumference and waist to height ratio with BMI. A significant (p<0.01) positive but weak correlation between both systolic and diastolic blood pressure and BMI was found. The relationship of BMI with diastolic BP was stronger than systolic BP. A similar relationship was also found in WC and WHtR. Age had a weak negative correlation with both BMI (-0.120) significant at the 0.01 level and WC (-0.004) significant at the 0.05 level but had a weak positive correlation with WHtR (0.054) (P-value <0.05).
Table 4. Correlation between BMI, WHtR, WC, SBP, DBP and age
|
BMI
|
WC (CM)
|
WHtR
|
SBP
|
DBP
|
Age
|
BMI
|
1
|
0.682**
|
0.770**
|
0.154**
|
0.214**
|
-0.120**
|
WC (CM)
|
0.682**
|
1
|
0.884**
|
0.188**
|
0.192**
|
-0.004
|
WHtR
|
0.770**
|
0.884**
|
1
|
0.168**
|
0.183**
|
0.054*
|
SBP
|
0.154**
|
0.188**
|
0.168**
|
1
|
0.726**
|
0.137**
|
DBP
|
0.214**
|
0.192**
|
0.183**
|
0.726**
|
1
|
-0.007
|
Age
|
-0.120**
|
-0.004
|
0.054*
|
0.137**
|
-.007
|
1
|
Abbreviations: BMI: Body Mass Index; CM: Centimeters; WC: Waist Circumference; WHtR: Waist to Height Ratio.
** Correlation is significant at the 0.01 level (2-tailed).
* Correlation is significant at the 0.05 level (2-tailed).
Receiver operating characteristic (ROC) analyses were used to determine the relative ability of the three obesity metrics to predict HTN, as depicted in Fig. 1 and Table 5. The areas under the curve (AUCs) were significantly higher than 0.5 for BMI (0.570, 95% CI: 0.548-0.592), WC (0.585, 95% CI: 0.563-0.607) and WHtR (0.586, 95% CI: 0.564-0.608). In both genders, the area under the curve was significantly higher than 0.5 (P<0.01). In all age groups, the area under the curve was also significantly higher than 0.5.
Table 5. Sex- and age-specific comparisons of the area under the receiver operating characteristic (ROC) curves of body mass index (BMI), waist circumference (WC) and waist to height ratio (WHtR)
|
|
Area (95% CI) under the curve
|
|
|
BMI
|
WC (CM)
|
WHtR
|
All
|
|
0.593(0.569-0.616)*
|
0.610 (0.586-0.633)*
|
0.602 (0.578-0.625)*
|
Sex
|
Male
|
0.620 (0.585-0.654)*
|
0.620 (0.586-0.655)*
|
0.629 (0.595-0.664)*
|
|
Female
|
0.581 (0.549-0.614)*
|
0.598 (0.566-0.630)*
|
0.590 (0.558-0.623)*
|
Age
|
40-54
|
0.600 (0.570-0.631)*
|
0.606 (0.563-0.625)*
|
0.594 (0.563-0.625)*
|
|
55-69
|
0.610 (0.572-0.648)*
|
0.620 (0.583-0.658)*
|
0.609 (0.572-0.647)*
|
Abbreviations: BMI: Body Mass Index; CM: Centimeters; WC: Waist Circumference; WHtR: Waist to Height Ratio.
* p<0.01