Overall cohort
The PURE-Saudi study enrolled 2047 participants, with mean age of 46.5±9.12 years (Table 1). There were 1165 men (56.9%) and 882 women (43.1%). Around one third of the total cohort had low educational level.
CVD risk factors
The mean body mass index (BMI) of the participants was 30.6, where majority of them were either overweight (35.3%) or obese (49.6%). Among obese patients, 30% had BMI between 30-35, and 19.5% had BMI > 35. The prevalence of abdominal obesity defined as waist circumference >102 cm (men) or >88 cm (women) was 49%. This prevalence is increased to 74.3% when the measured waist circumference >90 cm (men) or >85 cm (women).
The prevalence of hypertension was 30.3%, out of which only 61.1% were aware of it, 58.9% were treated and 30.7% participants achieved blood pressure control.
The prevalence of diabetes was 25.1%, out of which 2.7% were on insulin therapy, 60.7% received oral hypoglycemic agents (OHA), 6.6% received both (insulin and OHA), and 30% received no treatment. About one third (32.1%) had high total cholesterol level, however, history of stroke was found in 0.98%, heart failure in 0.64%, and coronary heart disease in 2.5%. In addition, the median INTERHEART risk score was 11.
Health behaviors and psychosocial factors
Approximately 34.4% of the total cohort reported eating unhealthy diet, 69.4% of participants reported low physical activity, 12.2% were current smokers, and 10.6% were former smokers. Moreover, the prevalence of self-reported of being sad or blue was 15.4%, while 16.9% had reported history of several feeling of stress and 6.8% had permanent feeling of stress.
Men vs Women
Compared to women, men have significantly higher proportion of current smoking (21% vs 0.45%, p<0.001) or former smoking (17.9% vs 0.91%, p<0.001), diabetes (28.2% vs 21.3%, p<0.001), obesity with BMI 30-35 (39.9% vs 32.4%, p<0.001), history of ischemic heart disease (3.2% vs 1.6%, p=0.02), and the median INTERHEART risk score (13% vs 10%, p<0.001). On the other hand, women had higher prevalence of obesity with BMI > 35 (26.1% vs 14.5%, p<0.001), central obesity (70.7% vs 32.7%, p<0.001), self-reporting of being sad (22.7%, vs 9.9% p<0.001), several feeling of stress (23.1% vs 12.4%, p<0.001) or permanent feeling of stress (9.9% vs 4.5%, p<0.001), and low level of education (46.6% vs 20.2%, p<0.001) (Table 1 and Figure A).
The awareness, treatment, and control of blood pressure were similar among women and men (61.3% vs 60.9%, 60.9% vs 57.6%, 34.5% vs 28.3%, (P =0.93, P =0. 41, P =0.10)) respectively. In addition, men were more likely to have lower HDL-cholesterol levels compared with women (Additional Table 1).
Table 1. Characteristics and the prevalence of cardiovascular disease risk factors; in the PURE-Saudi study.
Characteristics
|
Overall
|
Men
|
Women
|
p-value1
|
N (%)
|
2047
|
1165 (56.91)
|
882 (43.09)
|
|
Demographics
|
Age (year), mean ± SD
|
46.50 ± 9.12
|
47.55 ± 9.40
|
45.10 ± 8.55
|
< 0.001
|
Low educational level, n (%) †
|
646 (31.56)
|
235 (20.17)
|
411 (46.60)
|
< 0.001
|
Behavioral risk factors
|
Smoking status, n (%) ‡
|
|
|
|
|
Current smoker
|
249 (12.16)
|
245 (21.03)
|
4 (0.45)
|
< 0.001
|
Former smoker
|
217 (10.60)
|
209 (17.94)
|
8 (0.91)
|
< 0.001
|
Unhealthful diet, n (%) §
|
702 (34.39)
|
397 (56.55)
|
305 (43.45)
|
0.827
|
Low physical activity, n (%) ¶
|
1415 (69.40)
|
805 (69.34)
|
610 (69.48)
|
0.946
|
Current alcohol use, n (%)
|
24 (1.17)
|
24 (2.06)
|
0 (0.00)
|
< 0.001
|
Hypertension
|
Hypertension, n (%) ◊
|
620 (30.29)
|
382 (32.79)
|
238 (26.98)
|
0.005
|
Awareness among known hypertensive patients, n (%)
|
379 (61.13)
|
233 (60.99)
|
146 (61.34)
|
0.931
|
Treated hypertension among known hypertensive patients, n (%)
|
365 (58.87)
|
220 (57.59)
|
145 (60.92)
|
0.412
|
Controlled (ie SBP < 140 mm Hg) among those known to be hypertensive patients, n (%)
|
190 (30.65)
|
108 (28.27)
|
82 (34.45)
|
0.104
|
Treated hypertension and SBP ≥ 140 mmgH and/or DBP ≥ 90mmgH, n (%)
|
175 (47.95)
|
112 (50.91)
|
63 (43.45)
|
0.163
|
Treated hypertension and SBP > 120 mmgH and/or DBP > 80 mmgH, n (%)
|
318 (87.12)
|
198 (90)
|
120 (82.76)
|
0.043
|
Treated hypertension and SBP > 130 mmgH and/or DBP > 80 mmgH, n (%)
|
272 (76.19)
|
173 (79.36)
|
99 (71.22)
|
0.078
|
Diabetes
|
Diabetes, n (%) **
|
516 (25.21)
|
328 (28.15)
|
188 (21.32)
|
< 0.001
|
Among diabetic patients
|
|
|
|
0.093
|
On insulin alone
|
14 (2.71)
|
5 (1.52)
|
9 (4.79)
|
|
On OHA alone
|
313 (60.66)
|
200 (60.98)
|
113 (60.11)
|
|
on both
|
34 (6.59)
|
19 (5.79)
|
15 (7.98)
|
|
not on drug treatment
|
155 (30.04)
|
104 (31.71)
|
51 (27.13)
|
|
Dyslipidemia
|
Total Cholesterol > 5.2 mmol/L and LDL > 3.5 mmol/L, n (%) Ⱶ
|
569 (32.1)
|
234 (31.2)
|
335 (32.68)
|
0.508
|
Obesity
|
BMI, mean
|
30.6 ± 5.9
|
29.7 ±5.4
|
31.9 4 ± 6.3
|
< 0.001
|
BMI, n (%) ††
|
|
|
|
< 0.001
|
< 25
|
310 (15.15)
|
205 (17.60)
|
105 (11.92)
|
|
25-30
|
722 (35.29)
|
462 (39.66)
|
260 (29.51)
|
|
31-35
|
613(29.96)
|
463(39.78)
|
286(32.43)
|
|
> 35
|
399 (19.50)
|
169 (14.52)
|
230 (26.08)
|
|
Abdominal obesity, n (%)
|
|
|
|
|
Waist circumference > 102 cm (men) or > 88 cm (women)
|
1005 (49.1)
|
381 (32.7)
|
624 (70.75)
|
< 0.001
|
Waist circumference > 90 cm (men) or > 85 cm (women)
|
1521 (74.3)
|
835 (71.67)
|
686 (77.78)
|
0.002
|
Psychosocial
|
Self-report of being sad or “blue”, n (%)
|
315 (15.40)
|
115 (9.88)
|
200 (22.68)
|
< 0.001
|
General feeling of stress, n (%)
|
|
|
|
|
Several periods
|
339 (16.93)
|
143 (12.40)
|
196 (23.09)
|
< 0.001
|
Permanent
|
136 (6.79)
|
52 (4.51)
|
84 (9.89)
|
< 0.001
|
Medical History
|
History of ischemic heart disease (angina, MI or any coronary revascularization), n (%)
|
51 (2.49)
|
37 (3.18)
|
14 (1.59)
|
0.022
|
History of stroke, n (%)
|
20 (0.98)
|
12 (1.03)
|
8 (0.91)
|
0.779
|
History of heart failure, n (%)
|
13 (0.64)
|
5 (0.43)
|
8 (0.91)
|
0.178
|
INTERHEART Risk Score, median (25th-75th, IQR)
|
11.00 (8.00,16.00)
|
13.00 (9.00,18.00)
|
10.00 (6.00,14.00)
|
< 0.001
|
1 P-values refer to the results of either chi-square tests (for categorical variables) or t-tests (for continuous variables comparing the mean between categories.
Young vs Middle vs Old age
Compared to the younger and middle age groups (35-49 years and 50-59 years), older participants (60-70 years) had higher prevalence of low physical activity (75.2% vs 66.8% and 73.9% , p=0.002), hypertension (65% vs 18.2% and 48.4%, p <0.001), diabetes (57.5% vs 12.9% and 44.9%, p<0.001), low level of education (62.8% vs 21.7% and 44.9%, p<0.001), stroke (3.9% vs 0.4% and 1.1%, p<0.001), history of heart failure (1.8% vs 0.15% and 1.5%, p<0.001), and history of ischemic heart disease (7.5% vs 1.1% and 4.1%, p<0.001) (Table 2 and Figure B). The awareness and treatment of blood pressure were higher among older participants compared with middle and younger individuals (73.5% vs 70.04% and 45.5%, 73.5% vs 69.2% and 40.7%, P < 0.0001 for all).
While, middle age participants had more controlled of blood pressure compared to young and older individuals (39.2% vs 19.9% and 35.4%, P < 0.0001). However, younger age groups reported more consumption of unhealthy diet (38.9% and 25.2% vs 26.5%, p<0.001), general feeling of permanent stress (9.1% and 2.4% vs 1.9%, p<0.001), and self-reporting of being sad (18.6% and 10% vs 7.1%, p<0.001). The prevalence of obesity with BMI 30-35 and BMI >35 was 34.1% and 21.8% in the middle age group compared to 28.7% and 19.4% in the young age, and 28.8% and 15.5% in older age groups (0.001) respectively. Moreover, the median level of glucose and triglycerides were significantly increased with advanced age (Additional Table 2).
Table 2. Prevalence of cardiovascular disease risk factors stratified by age groups in the PURE-Saudi study.
Characteristics
|
35-49 yrs
|
50-59 yrs
|
60-70 yrs
|
p-value1
|
N (%)
|
1352 (66.05)
|
469 (22.91)
|
226 (11.04)
|
|
Demographics
|
Low educational level, n (%)
|
293 (21.67)
|
211 (44.99)
|
142 (62.83)
|
< 0.001
|
Behavioral risk factors
|
Smoking status, n (%)
|
|
|
|
|
Current smoker
|
181 (13.39)
|
48 (10.23)
|
20 (8.85)
|
0.054
|
Former smoker
|
124 (9.17)
|
60 (12.79)
|
33 (14.60)
|
0.011
|
Unhealthful diet, n (%)
|
524 (38.90)
|
118 (25.21)
|
60 (26.55)
|
< 0.001
|
Low physical activity, n (%)
|
899 (66.84)
|
346 (73.93)
|
170 (75.22)
|
0.002
|
Current alcohol use, n (%)
|
14 (1.04)
|
7 (1.49)
|
3 (1.33)
|
0.632
|
Hypertension
|
Hypertension, n (%)
|
246 (18.20)
|
227 (48.40)
|
147 (65.04)
|
< 0.001
|
Aware among known hypertensive patients, n (%)
|
112 (45.53)
|
159 (70.04)
|
108 (73.47)
|
< 0.001
|
Treated hypertension among known hypertensive patients, n (%)
|
100 (40.65)
|
157 (69.16)
|
108 (73.47)
|
< 0.001
|
Controlled among known hypertensive patients, n (%)
|
49 (19.92)
|
89 (39.21)
|
52 (35.37)
|
< 0.001
|
Treated hypertension and SBP ≥ 140 mmgH and/or DBP ≥ 90 mmgH, n (%)
|
51 (51.00)
|
68 (43.31)
|
56 (51.85)
|
0.304
|
Treated hypertension and SBP > 120mmgH and/or DBP > 80mmgH, n (%)
|
86 (86.00)
|
135 (85.99)
|
97 (89.81)
|
0.609
|
Treated hypertension and SBP > 130 mmgH and/or DBP > 80 mmgH, n (%)
|
80(80.81)
|
115(73.72)
|
77(75.49)
|
0.423
|
Diabetes
|
Diabetes, n (%)
|
175 (12.94)
|
211 (44.99)
|
130 (57.52)
|
< 0.001
|
Among diabetic patients
|
|
|
|
0.831
|
On insulin alone
|
5 (2.86)
|
6 (2.84)
|
3 (2.31)
|
|
On OHA alone
|
105 (60.00)
|
130 (61.61)
|
78 (60.00)
|
|
on both
|
12 (6.86)
|
10 (4.74)
|
12 (9.23)
|
|
not on drug Rx
|
53 (30.29)
|
65 (30.81)
|
37 (28.46)
|
|
Dyslipidemia
|
Total Cholesterol > 5.2 mmol/L and LDL > 3.5 mmol/L, n (%)
|
380 (32.45%)
|
124 (29.95%)
|
65 (34.21%)
|
0.514
|
Obesity
|
BMI, mean
|
30.6 ± 6.03
|
31.4 ± 5.53
|
29.5 ± 5.7 4
|
0.003
|
BMI, n (%)
|
|
|
|
< 0.001
|
< 25.0
|
211 (15.62)
|
46 (9.81)
|
53 (23.45)
|
|
25.0-30.0
|
488 (36.12)
|
161 (34.33)
|
73 (32.30)
|
|
30.1- 35.0
|
388 (28.72)
|
160 (34.12)
|
65 (28.76)
|
|
> 35.0
|
262(19.39)
|
102(21.75)
|
35(15.49)
|
|
Abdominal obesity, n (%)
|
|
|
|
|
Waist circumference > 102 cm (men) or > 88 cm (women)
|
628 (46.45)
|
262 (55.86)
|
115 (50.88)
|
0.002
|
Waist circumference > 90 cm (men) or > 85 cm (women)
|
960 (71.01)
|
389 (82.94)
|
172 (76.11)
|
< 0.001
|
Psychosocial
|
Self-report of being sad or “blue”, n (%)
|
252 (18.65)
|
47 (10.02)
|
16 (7.08)
|
< 0.001
|
General feeling of stress, n (%)
|
|
|
|
|
Several periods
|
249 (18.64)
|
74 (16.30)
|
16 (7.55)
|
< 0.001
|
Permanent
|
121 (9.06)
|
11 (2.42)
|
4 (1.89)
|
< 0.001
|
Medical History
|
History of ischemic heart disease (angina or MI), n (%)
|
15 (1.11)
|
19 (4.05)
|
17 (7.52)
|
< 0.001
|
History of stroke, n (%)
|
6 (0.44)
|
5 (1.07)
|
9 (3.98)
|
< 0.001
|
History of heart failure, n (%)
|
2 (0.15)
|
7 (1.49)
|
4 (1.77)
|
<0.001
|
INTERHEART Risk Score, median (25th-75th, IQR)
|
10.00 (7.00,14.00)
|
14.00 (10.00,19.00)
|
16.00 (12.00,21.00)
|
< 0.001
|
1 P-values refer to the results of either chi-square tests (for categorical variables) or analysis of variance (for continuous variables comparing the mean across categories.
Urban vs Rural
Participants living in urban areas represented 75.48% of the participants, while 24.5% lived in rural areas. Compared to urban areas, participants living in rural areas reported higher prevalence of diabetes (31.1% vs 23.3%, p<0.001), obesity (56.6% vs 47.3%, p<0.001), hypertension (35.5% vs 28.6%, p=0.004), and low level of education (46.4% vs 26.7%, p<0.001). In addition, the median BMI was higher among rural compared to urban participants (30.8% vs 29.7%, p<0.001).On the other hand, urban participants more likely to consume unhealthy diet (36% vs 29.4%,p=0.007), to self-report of being sad (17.6% vs 8.6%, p<0.001), to have several feeling of stress (19.7% vs 8.7%, p<0.001), and permanent feeling of stress (8.03% vs 3.02% p<0.001) (Table 3 and Figure C).
The awareness, treatment, and control of blood pressure were similar among the urban and rural communities (62.2% vs 58.4%, 60.1% vs 55.6%, 32.6% vs 25.8%, (P =0.38, P =0. 29, P =0.10) respectively. Furthermore, urban participants showed higher median in the glucose level and proportion in the glucose level between 6-7 mmol/L in non-diabetic patients (Additional Table 3).
Table 3. Prevalence of cardiovascular disease risk factors stratified by place of residence in the PURE-Saudi study.
Characteristics
|
Urban
|
Rural
|
p-value
|
N (%)
|
1545 (75.48)
|
502 (24.52)
|
|
Demographics
|
Age (year), mean ± SD
|
46.31 ± 8.88
|
47.07 ± 9.81
|
0.124
|
Low educational level, n (%)
|
413 (26.73)
|
233 (46.41)
|
< 0.001
|
Behavioral risk factors
|
Smoking status, n (%)
|
|
|
|
Current smoker
|
198 (12.82)
|
51 (10.16)
|
0.114
|
Former smoker
|
175 (11.33)
|
42 (8.37)
|
0.061
|
Unhealthful diet, n (%)
|
556 (36.01)
|
146 (29.38)
|
0.007
|
Low physical activity, n (%)
|
1061 (68.72)
|
354 (71.52)
|
0.240
|
Current alcohol use, n (%)
|
18 (1.17)
|
6 (1.20)
|
0.956
|
Hypertension
|
Hypertension, n (%)
|
442 (28.61)
|
178 (35.46)
|
0.004
|
Aware among known hypertensive patients, n (%)
|
275 (62.22)
|
104 (58.43)
|
0.381
|
Treated hypertension among known hypertensive patients, n (%)
|
266 (60.18)
|
99 (55.62)
|
0.296
|
Controlled among known hypertensive patients, n (%)
|
144 (32.58)
|
46 (25.84)
|
0.100
|
Treated hypertension and SBP ≥140mmgH and/or DBP ≥ 90mmgH, n (%)
|
122 (45.86)
|
53 (53.54)
|
0.192
|
Treated hypertension and SBP > 120mmgH and/or DBP > 80mmgH, n (%)
|
227 (85.34)
|
91 (91.92)
|
0.095
|
Treated hypertension and SBP > 130 mmgH and/or DBP > 80mmgH, n (%)
|
191(73.46)
|
81(83.51)
|
0.047
|
Diabetes
|
Diabetes, n (%)
|
360 (23.30)
|
156 (31.08)
|
< 0.001
|
Among diabetic patients
|
|
|
< 0.001
|
on insulin
|
11 (3.06)
|
3 (1.92)
|
|
on OHA
|
249 (69.17)
|
64 (41.03)
|
|
on both
|
31 (8.61)
|
3 (1.92)
|
|
not on Rx
|
69 (19.17)
|
86 (55.13)
|
|
Dyslipidemia
|
Total Cholesterol > 5.2 mmol/L and LDL > 3.5 mmol/L, n (%)
|
439 (31.49%)
|
130 (34.12%)
|
0.330
|
Obesity
|
BMI, mean
|
30.4 ± 5.8
|
31.4 ± 6.23
|
0.037
|
BMI, n (%)
|
|
|
< 0.001
|
< 25.0
|
245 (15.87)
|
65 (12.95)
|
|
25.0-30.0
|
569 (36.85)
|
153 (30.48)
|
|
30.1- 35.0
|
454 (29.39)
|
159 (31.74)
|
|
> 35.0
|
275(17.80)
|
124(24.75)
|
|
Abdominal obesity, n (%)
|
|
|
|
Waist circumference > 102 cm (men) or > 88 cm (women)
|
754 (48.80)
|
251 (50.00)
|
0.641
|
Waist circumference > 90 cm (men) or > 85 cm (women)
|
1156 (74.82)
|
365 (72.71)
|
0.347
|
Psychosocial
|
Self-report of being sad or “blue”, n (%)
|
272 (17.62)
|
43 (8.57)
|
< 0.001
|
General feeling of stress, n (%)
|
|
|
|
Several periods
|
296 (19.65)
|
43 (8.67)
|
< 0.001
|
Permanent
|
121 (8.03)
|
15 (3.02)
|
< 0.001
|
Medical history
|
History of ischemic heart disease (angina or MI), n (%)
|
36 (2.33)
|
15 (2.99)
|
0.411
|
History of stroke, n (%)
|
12 (0.78)
|
8 (1.59)
|
0.118
|
History of heart failure, n (%)
|
8 (0.52)
|
5 (1.00)
|
0.327
|
INTERHEART Risk Score, median (25th-75th, IQR)
|
11.00 (8.00,16.00)
|
12.00 (7.00,17.00)
|
0.833
|
Follow-up
A total of 1996 out of 2047 participants responded to follow-up after baseline, resulting in a response rate of 97.5%. Current mean (SD) and median (IQR) duration of follow-up is 4.3 (1.4) and 3.4 (3.2-6.1) years respectively. We have attempted to contact participants for at least three times. There were 6 patients diagnosed with cancer and total of 22 deaths (at rate of 0.07 and 0.26 per 100 person years of follow-up respectively). The overall rates of major cardiovascular events showed similar pattern to that for mortality, where 24 had a myocardial infarction, 6 had a stroke, 4 had heart failure, and 34 had at least one major cardiovascular events with rates of 0.29, 0.07, 0.05, and 0.41 per 100 person years of follow-up respectively.