Overall cohort
The PURE-Saudi study enrolled 2047 participants, with a 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 a low educational level.
CVD risk factors
The mean BMI of the participants was 30.6, with the majority either overweight (35.3%) or obese (49.6%). Among patients with obesity, 30% had a BMI of 30–35, and 19.5% had a BMI >35. The prevalence of abdominal obesity, defined as a waist circumference >102 cm (men) or >88 cm (women), was 49%. This prevalence increased to 74.3% when the waist circumference cutoff was >90 cm (men) or >85 cm (women).
The prevalence of hypertension was 30.3%, of whom only 61.1% were aware of it, 58.9% were treated, and 30.7% had achieved blood pressure control. The prevalence of diabetes was 25.1%, and of these participants, 2.7% were on insulin therapy, 60.7% received oral hypoglycemic agents (OHAs), 6.6% received both (insulin and OHAs), and 30% received no treatment. About one third (32.1%) had a high total cholesterol level, and 1% had a history of stroke, 0.6% a history of heart failure, and 2.5% a history of coronary heart disease. The median INTERHEART risk score for the total cohort was 11.
Health behaviors and psychosocial factors
Approximately 34.4% of the total cohort reported eating an unhealthy diet, 69.4% reported low physical activity, 12.2% were current smokers, and 10.6% were former smokers. Moreover, the prevalence of self-reported sadness or feeling blue was 15.4%, whereas 16.9% reported a history of feeling stress during several periods, and 6.8% had a permanent feeling of stress.
Men compared with women
Compared with women, men had a 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), and history of ischemic heart disease (3.2% vs 1.6%, P = 0.02), and a higher median INTERHEART risk score (13% vs 10%, P < 0.001). 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-reported sadness (22.7%, vs 9.9%, P < 0.001), several periods of stress (23.1% vs 12.4%, P < 0.001), a 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 1).
Regarding blood pressure, for women compared with men, awareness (61.3% vs 60.9%, P = 0.93), treatment (60.9% vs 57.6%, P = 0. 41), and control (34.5% vs 28.3%, P = 0.10) were similar. Men were more likely, however, to have lower high-density lipoprotein 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
|
P1
|
N (%)
|
2047
|
1165 (56.9)
|
882 (43.1)
|
|
Demographics
|
Age (y), mean ± SD
|
46.5 ± 9.1
|
47.5 ± 9.4
|
45.1 ± 8.5
|
<0.001
|
Low educational level, n (%)
|
646 (31.6)
|
235 (20.2)
|
411 (46.6)
|
<0.001
|
Behavioral risk factors
|
Smoking status, n (%)
|
|
|
|
|
Current smoker
|
249 (12.2)
|
245 (21)
|
4 (0.4)
|
<0.001
|
Former smoker
|
217 (10.6)
|
209 (17.9)
|
8 (0.9)
|
<0.001
|
Unhealthful diet, n (%)
|
702 (34.4)
|
397 (56.5)
|
305 (43.4)
|
0.827
|
Low physical activity, n (%)
|
1415 (69.4)
|
805 (69.3)
|
610 (69.5)
|
0.946
|
Current alcohol use, n (%)
|
24 (1.2)
|
24 (2.1)
|
0 (0.0)
|
<0.001
|
Hypertension
|
Hypertension, n (%)
|
620 (30.3)
|
382 (32.8)
|
238 (27)
|
0.005
|
Awareness among patients with known hypertension, n (%)
|
379 (61.1)
|
233 (61)
|
146 (61.3)
|
0.931
|
Treated hypertension among patients with known hypertension, n (%)
|
365 (58.9)
|
220 (57.6)
|
145 (60.9)
|
0.412
|
Controlled hypertension among those with known hypertension, n (%)
|
190 (30.6)
|
108 (28.3)
|
82 (34.4)
|
0.104
|
Treated hypertension and SBP ≥140 mmHg and/or DBP ≥90 mmHg, n (%)
|
175 (47.9)
|
112 (50.9)
|
63 (43.4)
|
0.163
|
Treated hypertension and SBP >120 mmHg and/or DBP >80 mmHg, n (%)
|
318 (87.1)
|
198 (90)
|
120 (82.8)
|
0.043
|
Treated hypertension and SBP >130 mmHg and/or DBP >80 mmHg, n (%)
|
272 (76.2)
|
173 (79.4)
|
99 (71.2)
|
0.078
|
Diabetes
|
Diabetes, n (%)
|
516 (25.2)
|
328 (28.1)
|
188 (21.3)
|
<0.001
|
Among patients with diabetes
|
|
|
|
0.093
|
On insulin alone
|
14 (2.7)
|
5 (1.5)
|
9 (4.8)
|
|
On OHA alone
|
313 (60.7)
|
200 (61)
|
113 (60.1)
|
|
On both
|
34 (6.6)
|
19 (5.8)
|
15 (8)
|
|
Not on prescription drug
|
155 (30)
|
104 (31.7)
|
51 (27.1)
|
|
Dyslipidemia
|
Total cholesterol >5.2 mmol/l and low-density lipoprotein cholesterol >3.5 mmol/l, n (%)
|
569 (32.1)
|
234 (31.2)
|
335 (32.7)
|
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 (15.1)
|
205 (17.6)
|
105 (11.9)
|
|
25–30
|
722 (35.3)
|
462 (39.7)
|
260 (29.5)
|
|
31–35
|
613(30)
|
463(39.8)
|
286(32.4)
|
|
>35
|
399 (19.5)
|
169 (14.5)
|
230 (26.1)
|
|
Abdominal obesity, n (%)
|
|
|
|
|
Waist circumference >102 cm (men) or >88 cm (women)
|
1005 (49)
|
381 (32.7)
|
624 (70.7)
|
<0.001
|
Waist circumference >90 cm (men) or >85 cm (women)
|
1521 (74.3)
|
835 (71.7)
|
686 (77.8)
|
0.002
|
Psychosocial
|
Self-report of feeling sad or “blue,” n (%)
|
315 (15.4)
|
115 (9.9)
|
200 (22.7)
|
<0.001
|
General feeling of stress, n (%)
|
|
|
|
|
Several periods of stress
|
339 (16.9)
|
143 (12.4)
|
196 (23.1)
|
<0.001
|
Permanent stress
|
136 (6.8)
|
52 (4.5)
|
84 (9.9)
|
<0.001
|
Medical history
|
History of ischemic heart disease (angina, myocardial infarction, or any coronary revascularization), n (%)
|
51 (2.5)
|
37 (3.2)
|
14 (1.6)
|
0.022
|
History of stroke, n (%)
|
20 (1)
|
12 (1)
|
8 (0.9)
|
0.779
|
History of heart failure, n (%)
|
13 (0.6)
|
5 (0.4)
|
8 (0.9)
|
0.178
|
INTERHEART Risk Score, median (25th–75th, IQR)
|
11 (8,16)
|
13 (9,18)
|
10 (6,14)
|
<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.
BMI, body mass index; DBP, diastolic blood pressure; IQR, interquartile range; OHA, oral hypoglycemic agent; SBP, systolic blood pressure
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 a higher prevalence of low physical activity (66.8% younger vs 73.9% middle vs 75.2% older, P = 0.002), hypertension (18.2% vs 48.4% vs 65%, P < 0.001), diabetes (12.9% vs 45% vs 57.5%, P < 0.001), low education level (21.7% vs 45% vs 62.8%, P < 0.001), stroke (0.4% vs 1.1% vs 4%, P < 0.001), history of heart failure (0.1% vs 1.5% vs 1.8%, P < 0.001), and history of ischemic heart disease (1.1% vs 4.1% vs 7.5%, P < 0.001) (Table 2 and Figure 2). Awareness and treatment of blood pressure were higher among older participants compared with middle-aged and younger individuals (awareness: 45.5% for younger vs 70% middle-aged vs 73.5% older; 40.7% vs 69.2% vs 73.5% for treatment; P < 0.0001 for all).
A greater proportion of middle-aged participants (39.2%) had more controlled blood pressure compared to younger (19.9%) and older (35.4%) individuals (P < 0.0001). However, the younger age group more often reported consumption of an unhealthy diet (38.9% vs 25.2% middle-aged vs 26.5% older respondents, P < 0.001), general feeling of permanent stress (9.1% vs 2.4% vs 1.9%, P < 0.001), and being sad (18.6% vs 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-aged group compared to 28.7% and 19.4% in the younger group and 28.8% and 15.5% in older age groups (P < 0.001) respectively. Moreover, the median level of glucose and triglycerides was significantly increased in the older age group (Additional Table 2).
Table 2. Prevalence of cardiovascular disease risk factors stratified by age groups in the PURE-Saudi study.
Characteristics
|
35–49 y
|
50–59 y
|
60–70 y
|
P1
|
N (%)
|
1352 (66)
|
469 (22.9)
|
226 (11)
|
|
Demographics
|
Low education level, n (%)
|
293 (21.7)
|
211 (45)
|
142 (62.8)
|
<0.001
|
Behavioral risk factors
|
Smoking status, n (%)
|
|
|
|
|
Current smoker
|
181 (13.4)
|
48 (10.2)
|
20 (8.8)
|
0.054
|
Former smoker
|
124 (9.2)
|
60 (12.8)
|
33 (14.6)
|
0.011
|
Unhealthful diet, n (%)
|
524 (38.9)
|
118 (25.2)
|
60 (26.5)
|
<0.001
|
Low physical activity, n (%)
|
899 (66.8)
|
346 (73.9)
|
170 (75.2)
|
0.002
|
Current alcohol use, n (%)
|
14 (1)
|
7 (1.5)
|
3 (1.3)
|
0.632
|
Hypertension
|
Hypertension, n (%)
|
246 (18.2)
|
227 (48.4)
|
147 (65)
|
<0.001
|
Awareness among patients with known hypertension, n (%)
|
112 (45.5)
|
159 (70)
|
108 (73.5)
|
<0.001
|
Treated hypertension among patients with known hypertension, n (%)
|
100 (40.6)
|
157 (69.2)
|
108 (73.5)
|
<0.001
|
Controlled hypertension among those with known hypertension, n (%)
|
49 (19.9)
|
89 (39.2)
|
52 (35.4)
|
<0.001
|
Treated hypertension and SBP ≥140 mmHg and/or DBP ≥90 mmHg, n (%)
|
51 (51)
|
68 (43.3)
|
56 (51.8)
|
0.304
|
Treated hypertension and SBP >120 mmHg and/or DBP >80 mmHg, n (%)
|
86 (86)
|
135 (86)
|
97 (89.8)
|
0.609
|
Treated hypertension and SBP >130 mmHg and/or DBP >80 mmHg, n (%)
|
80 (80.8)
|
115 (73.7)
|
77 (75.5)
|
0.423
|
Diabetes
|
Diabetes, n (%)
|
175 (12.9)
|
211 (45)
|
130 (57.5)
|
<0.001
|
Among patients with diabetes
|
|
|
|
0.831
|
On insulin alone
|
5 (2.9)
|
6 (2.8)
|
3 (2.3)
|
|
On OHA alone
|
105 (60)
|
130 (61.6)
|
78 (60)
|
|
On both
|
12 (6.9)
|
10 (4.7)
|
12 (9.2)
|
|
Not on prescription drug
|
53 (30.3)
|
65 (30.8)
|
37 (28.5)
|
|
Dyslipidemia
|
Total cholesterol >5.2 mmol/l and low-density lipoprotein cholesterol >3.5 mmol/l, n (%)
|
380 (32.4)
|
124 (29.9)
|
65 (34.2)
|
0.514
|
Obesity
|
BMI, mean
|
30.6 ± 6
|
31.4 ± 5.5
|
29.5 ± 5.7
|
0.003
|
BMI, n (%)
|
|
|
|
<0.001
|
<25.0
|
211 (15.6)
|
46 (9.8)
|
53 (23.4)
|
|
25.0–30.0
|
488 (36.1)
|
161 (34.3)
|
73 (32.3)
|
|
30.1–35.0
|
388 (28.7)
|
160 (34.1)
|
65 (28.8)
|
|
>35.0
|
262(19.4)
|
102(21.7)
|
35(15.5)
|
|
Abdominal obesity, n (%)
|
|
|
|
|
Waist circumference >102 cm (men) or >88 cm (women)
|
628 (46.4)
|
262 (55.9)
|
115 (50.9)
|
0.002
|
Waist circumference >90 cm (men) or >85 cm (women)
|
960 (71)
|
389 (82.9)
|
172 (76.1)
|
<0.001
|
Psychosocial
|
Self-report of being sad or “blue,” n (%)
|
252 (18.6)
|
47 (10)
|
16 (7.1)
|
<0.001
|
General feeling of stress, n (%)
|
|
|
|
|
Several periods of stress
|
249 (18.6)
|
74 (16.3)
|
16 (7.5)
|
<0.001
|
Permanent stress
|
121 (9.1)
|
11 (2.4)
|
4 (1.9)
|
<0.001
|
Medical history
|
History of ischemic heart disease (angina or myocardial infarction), n (%)
|
15 (1.1)
|
19 (4.0)
|
17 (7.5)
|
<0.001
|
History of stroke, n (%)
|
6 (0.4)
|
5 (1.1)
|
9 (4)
|
<0.001
|
History of heart failure, n (%)
|
2 (0.1)
|
7 (1.5)
|
4 (1.8)
|
<0.001
|
INTERHEART Risk Score, median (25th–75th, IQR)
|
10 (7,14)
|
14 (10,19)
|
16 (12,21)
|
<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).
BMI, body mass index; DBP, diastolic blood pressure; IQR, interquartile range; OHA, oral hypoglycemic agent; SBP, systolic blood pressure
Urban vs rural
Of the cohort, 75.48% lived in urban areas. Compared to those in urban areas, a greater proportion of those living in rural areas reported diabetes (31.1% rural vs 23.3% urban, P < 0.001), obesity (56.6% vs 47.3%, P < 0.001), hypertension (35.5% vs 28.6%, P = 0.004), and low education level (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 were more likely to consume unhealthy diet (36% vs 29.4%, P = 0.007), self-report being sad (17.6% vs 8.6%, P < 0.001), have several periods of stress (19.7% vs 8.7%, P < 0.001), and have a permanent feeling of stress (8.03% vs 3.02%, P < 0.001) (Table 3 and Figure 3).
The awareness, treatment, and control of blood pressure were similar between the urban and rural communities (awareness: 62.2% urban vs 58.4% rural, P = 0.38; treatment: 60.1% vs 55.6%, P = 0.29; control: 32.6% vs 25.8%, P = 0.10). Furthermore, urban participants had a higher median glucose level and higher proportion with a glucose level of 6-7 mmol/l in participants without diabetes (Additional Table 3).
Table 3. Prevalence of cardiovascular disease risk factors stratified by place of residence in the PURE-Saudi study.
Characteristics
|
Urban
|
Rural
|
P1
|
N (%)
|
1545 (75.5)
|
502 (24.5)
|
|
Demographics
|
Age (y), mean ± SD
|
46.3 ± 8.9
|
47.1 ± 9.8
|
0.124
|
Low education level, n (%)
|
413 (26.7)
|
233 (46.4)
|
<0.001
|
Behavioral risk factors
|
Smoking status, n (%)
|
|
|
|
Current smoker
|
198 (12.8)
|
51 (10.2)
|
0.114
|
Former smoker
|
175 (11.3)
|
42 (8.4)
|
0.061
|
Unhealthful diet, n (%)
|
556 (36)
|
146 (29.4)
|
0.007
|
Low physical activity, n (%)
|
1061 (68.7)
|
354 (71.5)
|
0.240
|
Current alcohol use, n (%)
|
18 (1.2)
|
6 (1.2)
|
0.956
|
Hypertension
|
Hypertension, n (%)
|
442 (28.6)
|
178 (35.5)
|
0.004
|
Awareness among patients with known hypertension, n (%)
|
275 (62.2)
|
104 (58.4)
|
0.381
|
Treated hypertension among patients with known hypertension, n (%)
|
266 (60.2)
|
99 (55.6)
|
0.296
|
Controlled hypertension among those with known hypertension, n (%)
|
144 (32.6)
|
46 (25.8)
|
0.100
|
Treated hypertension and SBP ≥140 mmHg and/or DBP ≥90 mmHg, n (%)
|
122 (45.9)
|
53 (53.5)
|
0.192
|
Treated hypertension and SBP >120 mmHg and/or DBP >80 mmHg, n (%)
|
227 (85.3)
|
91 (91.9)
|
0.095
|
Treated hypertension and SBP >130 mmHg and/or DBP >80 mmHg, n (%)
|
191 (73.5)
|
81 (83.5)
|
0.047
|
Diabetes
|
Diabetes, n (%)
|
360 (23.3)
|
156 (31.1)
|
<0.001
|
Among patients with diabetes
|
|
|
<0.001
|
On insulin alone
|
11 (3.1)
|
3 (1.9)
|
|
On OHA alone
|
249 (69.2)
|
64 (41.0)
|
|
On both
|
31 (8.6)
|
3 (1.9)
|
|
Not on prescription drug
|
69 (19.2)
|
86 (55.1)
|
|
Dyslipidemia
|
Total cholesterol >5.2 mmol/l and low-density lipoprotein cholesterol >3.5 mmol/l, n (%)
|
439 (31.5)
|
130 (34.1)
|
0.330
|
Obesity
|
BMI, mean
|
30.4 ± 5.8
|
31.4 ± 6.2
|
0.037
|
BMI, n (%)
|
|
|
<0.001
|
<25.0
|
245 (15.9)
|
65 (12.9)
|
|
25.0–30.0
|
569 (36.8)
|
153 (30.5)
|
|
30.1–35.0
|
454 (29.4)
|
159 (31.7)
|
|
>35.0
|
275 (17.8)
|
124 (24.7)
|
|
Abdominal obesity, n (%)
|
|
|
|
Waist circumference >102 cm (men) or >88 cm (women)
|
754 (48.8)
|
251 (50)
|
0.641
|
Waist circumference >90 cm (men) or >85 cm (women)
|
1156 (74.8)
|
365 (72.7)
|
0.347
|
Psychosocial
|
Self-report of being sad or “blue,” n (%)
|
272 (17.6)
|
43 (8.6)
|
<0.001
|
General feeling of stress, n (%)
|
|
|
|
Several periods of stress
|
296 (19.6)
|
43 (8.7)
|
<0.001
|
Permanent stress
|
121 (8)
|
15 (3)
|
<0.001
|
Medical history
|
History of ischemic heart disease (angina or myocardial infarction), n (%)
|
36 (2.3)
|
15 (3)
|
0.411
|
History of stroke, n (%)
|
12 (0.8)
|
8 (1.6)
|
0.118
|
History of heart failure, n (%)
|
8 (0.5)
|
5 (1)
|
0.327
|
INTERHEART Risk Score, median (25th–75th, IQR)
|
11 (8,16)
|
12 (7,17)
|
0.833
|
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.
BMI, body mass index; DBP, diastolic blood pressure; IQR, interquartile range; OHA, oral hypoglycemic agent; SBP, systolic blood pressure
Follow-up
Of 2047 participants, 1996 responded to follow-up after baseline, for 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 at least three times. During the current follow-up, 6 patients had been diagnosed with cancer (0.07 per 100 person years of follow-up), and there were 22 deaths (0.26 per 100 person years of follow-up). The overall rates of major cardiovascular events showed a pattern similar to that for mortality: 24 had a myocardial infarction (0.29 per 100 person years of follow-up), 6 had a stroke (0.07 per 100 person years of follow-up), 4 had heart failure (0.05 per 100 person years of follow-up), and 34 had at least one major cardiovascular event (0.41 per 100 person years of follow-up).