Abdul Rahman Al-Nuaim

Prevalence of hypercholesterolemia in Saudi Arabia, epidemiological study

The objective of this study was to look at the pattern of serum total cholesterol concentration (TCC) distribution and the prevalence of hypercholesterolemia (HC) in Saudi Arabia. A cross-sectional national epidemiological household survey was carried out, consisting of 4539 Saudi subjects, over the age of 15 years. The sample was adjusted for gender, age, regional and residency, and urban versus rural population distribution. The following details were taken for each subject: height, weight, calculation of body mass index (BMI) and random blood samples for total cholesterol measurements. It was found that the mean TCC for all female subjects was significantly higher than for male subjects (4.24 versus 4 mmol/l). The mean TCC of female subjects, aged 40-59 years was higher, but not significantly so, than for male subjects (4.5 versus 4.4 mmol/l). There was a progressive increase in TCC with age, reaching a maximum at the fifth and sixth decades for male and female subjects, respectively. There was a progressive increase in mean TCC with increasing BMI values for male and female subjects with higher values of mean TCC for female subjects for any given BMI value. The prevalence of HC, 5.2-6.2 mmol/l was 9% and 11% for all male and female subjects, respectively (P = 0.74), whereas the prevalence of HC, > 6.2 mmol/l was 7% and 8% for male and female subjects, respectively (P = 0.52). The prevalence of HC 5.2-6.2 mmol/l for subjects aged 40-59 years was 14% and 10% for male and female subjects, respectively (P = 0.67), whereas the prevalence of HC > 6.2 mmol/l was 9% and 11% for male and female subjects, respectively (P = 0.6). There was a progressive increase in the prevalence of HC with age for male and female subjects. The prevalence of HC > 5.2 mmol/l increased with increasing BMI values. The prevalence of HC of female subjects was significantly higher than for male subjects among normal weight groups. The prevalence of HC (> 6.2 mmol/l) for female subjects was higher, however, not significant than for male subjects among overweight and obese groups. The prevalence of HC, whether for male or female subjects, was higher among diabetics when compared with non-diabetic subjects. The prevalence of HC (> 6.2 mmol/l) among male subjects was higher for smokers when compared with non-smokers. It was concluded that Saudi subjects have lower prevalence of HC than the European and American populations. This can partially be explained by the younger nature of the population. The prevalence of HC is likely to increase in the near future with the increasing percentage of the aged population in the community, and with the effects of a longer exposure to the acquired western life-style and nutritional habits, which is showing an impact with the increase in the prevalence of obesity. The cause of coronary heart disease is multifactorial, HC being one of the main contributors. Therefore, there is a need to study, in detail, the prevalence of other risk factors, such as: obesity, smoking, hypertension etc. There is a need to promote health awareness among the population with an emphasis on controlling weight and carrying out periodic cholesterol measurements.

High prevalence of metabolic risk factors for cardiovascular diseases among Saudi population, aged 30–64 years

Abstract Objective : Study the prevalence of metabolic risk factors for cardiovascular diseases, obesity, diabetes mellitus, hypercholesterolemia and other cholesterol related risk factors among Saudi population, aged 30–64 years. Design : Cross sectional national epidemiological randomized household survey. Subject : 2059 Saudi subjects, aged 30–64 years. Sample was representative and in accordance with the national population distribution with respect to age, gender, regional and residency, urban vs. rural, population distribution. Measurement : Height and weight with calculation of body mass index, blood samples were drawn and assayed for glucose, total cholesterol, triglyceride and high density lipoprotein. Low density lipoprotein and cholesterol/high density lipoprotein ratio were calculated. Oral glucose tolerance test was done for subjects with borderline random glucose concentration. The overall prevalence of diabetes mellitus was calculated. Results : Mean body mass index (BMI) was significantly higher among female subjects 28.3(6) vs. 26.6(4.6), P =0.0001. The 90th percentile of BMI was higher among female subjects across all age groups. The 90th percentile of BMI for Saudi subjects were higher across all age group than sex and age matched European subjects. Mean serum total cholesterol (TC) concentration was higher, however, not significant among female, compared with male subjects. The 90th percentile of serum TC concentration was higher among female, compared with male subjects for all age groups after the age of 40 years. The 90th percentile of serum TC concentration for Saudi subjects was lower across all age groups than sex and age matched European subjects. The prevalence of overweight was significantly higher among male subjects whereas the prevalence of obesity was significantly higher among female subjects. The prevalence of diabetes mellitus was significantly higher among female subjects whereas the prevalence of impaired glucose tolerance was significantly higher among male subjects. The prevalence of hypercholesterolemia, whether using cut-off levels of >5.2 mmol/l or >6.2 mmol/l. were similar between male and female subjects. They were lower than the prevalence of hypercholesterolemia among sex and age matched subjects whether from developed or from some developing countries. The prevalence of hypo HDL cholesterolemia, 6.5, for Saudi subjects was higher than some other developing countries. Conclusion : This study has shown high prevalence of metabolic risk factors for CVD. As atherosclerosis is ongoing process and considering the young nature of this country with 60% of population are

POPULATION-BASED EPIDEMIOLOGICAL STUDY OF THE PREVALENCE OF OVERWEIGHT AND OBESITY IN SAUDI ARABIA, REGIONAL VARIATION

This is a study of the pattern of distribution of body mass index and prevalence of overweight and obesity among the population of different regions of Saudi Arabia. It is a cross-sectional population-based national epidemiological randomized household survey. There were 13,177 Saudi subjects, over the age of 15 years. The sample was representative and in accordance with the national population distribution with respect to age, gender, regional and residency population distribution. Height and weight were measured for all study population. Body mass index (BMI) was calculated. WHO criteria was used for definition of overweight and obesity. The obesity/overweight (ob/ow) ratio was used to study the relation between prevalence of overweight and obesity. Mean BMI values for female subjects were significantly higher than for male subjects across all regions. Mean BMI values were highest at the fifth decade for male and female subjects in all regions. Mean and 90th percentile of BMI values of male and female subjects of the Eastern region across all age groups were higher than for other regions. There was a progressive increase in prevalence of overweight with age among male subjects; the highest prevalence was achieved in the age group 51-60 years across all the regions. The overall prevalence of overweight was higher among male subjects across all the regions. There was a progressive increase in the prevalence of obesity with age among male and female subjects. The highest was achieved in the age group of 41-50 years across all the regions. There was a regional variation with respect to the prevalence of overweight and obesity among Saudi subjects. The prevalence of overweight was higher among male subjects across all the regions, while the prevalence of obesity was higher among female subjects across all the regions. A high prevalence of obesity was observed in most of the regions. Underlying factors such as lifestyle, nutritional habits, social and cultural beliefs and habits in different regions need to be studied. There is a need to establish a national control program for combating obesity and related complications.

Serum total and fractionated cholesterol distribution and prevalence of hypercholesterolemia in urban and rural communities in Saudi Arabia

Hypercholesterolemia is recognized as an independent risk factor for cardiovascular diseases. Data on serum total cholesterol concentration distribution from Saudi Arabia are scarce. We have conducted a cross sectional, national, epidemiological randomized household survey to study the distribution of serum total cholesterol (TCC), low density lipoprotein (LDL) and high density lipoprotein (HDL) concentrations, total cholesterol/high density lipoprotein (CH/HDL) ratio and prevalence of hypercholesterolemia (HC) among subjects aged 25-64 years in urban and rural communities of Saudi Arabia. The sample was 2924 Saudi subjects which was adjusted in accordance with the national population distribution with respect to age, gender, regional and residency, urban vs. rural population distribution. Height and weight were measured with calculation of body mass index (BMI). Blood samples were drawn and assayed for total cholesterol, triglyceride, high density lipoprotein concentration and calculation of low density lipoprotein concentration. The mean of BMI was significantly higher among female subjects and significantly higher among urban subjects. The prevalence of obesity was higher among female subjects and higher, however, not significant, among urban subjects. Mean serum TCC was higher among rural subjects. Mean serum LDL concentration was higher among female subjects and higher among urban subjects. Mean serum HDL concentration was lower among female subjects and lower among urban subjects. Mean CH/HDL ratio was higher among female subjects and higher for urban subjects. Female and male subjects living in rural communities had the highest and lowest percentages of subjects with high concentrations of LDL, respectively. Female and male subjects, living in rural communities had the highest and lowest percentages of subjects with low concentration of HDL, respectively. Male and female subjects living in rural communities had the highest and lowest percentages of studied subjects with a high CH/HDL ratio. The age-adjusted prevalence of HC (5.2-6.2 mmol/l) was equal among all the four groups. The prevalence of HC (> 6.2 mmol/l) was significantly higher among rural male subjects, compared with their counterparts in urban areas, while it was equal among female subjects. There was an increase in age-specific prevalence of HC (> 6.2 mmol/l) with maximum prevalence achieved at an age of 56-64 years for urban subjects, while it was achieved a decade earlier for rural subjects. The prevalence of HC, in general, was higher among rural male and urban female subjects. In conclusion, among Saudi subjects, means of total, fractionated cholesterol concentration, CH/HDL ratio > 6.5 and prevalence of obesity were higher among urban female subjects. The prevalence of HC, whether > 5.2 or > 6.2 mmol/l was higher among rural subjects. The difference, however, reached significance among female subjects. There is a need to study the possible underlying factors for the increase in prevalence of HC among rural subjects with special emphasis on the food components and nutritional habits of rural communities in Saudi Arabia. There is also a need to establish a control program throughout the country with the aim of halting the upward trend in incidence of CVD through control of modifiable risk factor such as obesity and hypercholesterolemia.

Iodine deficiency in Saudi Arabia.

Data on the status of iodine deficiency in the Arabian peninsula is scarce. We have conducted a cross-sectional national epidemiological survey in Saudi Arabia to study the iodine status of Saudi schoolchildren, between eight and ten years, who were randomly selected, after taking into consideration the gender, provincial population and area distribution. Casual urine samples were collected and sent to the central laboratory for analysis. Clinical assessment for the presence of goiter was conducted in four areas with different geographical natures. The survey included 4638 subjects, and their median and mean (SD) of urinary iodine concentration was 18 and 17 m g/dL, respectively. We found provincial differences with respect to urinary iodine concentration and the percentage of subjects with urinary iodine concentration <10 m g/dL. The Southern province had the lowest median (11 m g/dL) and the highest percentage (45%) of subjects with urinary iodine concentration <10 m g/dL. On the other hand, subjects of the Western province had the highest median (24 m g/dL) and the lowest percentage (8%) of subjects with urinary iodine concentration <10 m g/dL. The clinical assessment revealed that the highest prevalence and more advanced grade of goiter (22%, 95% CI 19-25, grade 1; 8%, 95% CI 6-10, grade 2) was found in the Asir region, a high-altitude area in the Southern province. The lowest prevalence of goiter (4%, 95% CI 0.8-7.2, grade 1) was found in Gizan, an urban coastal community. There was a significant relationship between the prevalence of goiter and the urinary iodine concentration. The survey for iodine deficiency disorder (IDD) in Saudi Arabia has shown a mild degree of iodine deficiency in the Southern province. Odds ratio (OR) was used to study the statistical relationship between the prevalence of goiter and the urinary iodine concentration. There is a need to launch a control program to ensure the exclusive availability of iodized salt in Saudi Arabia, especially in the Southern province.

Effect of overweight and obesity on glucose intolerance and dyslipidemia in Saudi Arabia, epidemiological study

The aim of this study was to study the effect of overweight and obesity on glucose intolerance and dyslipidemia in Saudi Arabia. A cross-sectional national epidemiological randomized household survey of 2059 Saudi subjects, aged 30-64 years was carried out. The sample was representative and was in accordance with the national population distribution with respect to age, gender, regional and residency, urban versus rural population distribution. The subjects height and weight for the calculation of body mass index (BMI) was measured. Blood samples were drawn and assayed for glucose, total cholesterol, triglyceride and high density lipoprotein (HDL). Low density lipoprotein (LDL) was calculated. The oral glucose tolerance test was carried out for subjects with borderline random glucose concentration and the overall prevalence of diabetes mellitus was calculated. A high prevalence of obesity among the Saudi population was observed and mean serum glucose concentration was significantly higher among overweight and obese groups. The prevalence of diabetes mellitus was significantly higher among obese groups. The mean serum triglyceride concentration was only significantly higher among male obese groups. There was no significant difference in the mean of serum total cholesterol concentration between control and obese groups. Mean serum HDL concentration was lower among the obese group, however, the difference was not significant. There was no significant difference in the prevalence of hypercholesterolemia between control and obese groups. Prevalence of hypertriglyceridemia was higher among obese groups and was significantly higher among male subjects across all BMI groups. Prevalence of hypo HDL cholesterolemia exceeded 50% of the study population. Obesity, glucose intolerance, hypertriglyceridemia, hypo HDL cholesterolemia and features of insulin resistance syndrome (IRS) are widely prevalent among the Saudi population over the age of 40 years. IRS is probable a significant contributor to the pathologic process of cardiovascular (CVD) disease among the Saudi population, especially in view of the low prevalence of hypercholesterolemia.

Hyperlipidemia among Saudi diabetic patients - pattern and clinical characteristics.

Premature development of atherosclerosis and increased rate of coronary artery and peripheral vascular diseases are characteristic features of patients with diabetes mellitus. Hyperlipidemia is an important precipitating factor for these diseases. Several patterns of lipid alteration among diabetics were described; the most common is hypertriglyceridemia. This study was constructed to look at the pattern of lipid alteration among Saudi diabetic patients. Forty-three percent of diabetic patients were dyslipidemic with an equal distribution of dyslipidemic patients with respect to type of dyslipidemia, i.e., combined hyperlipidemia, hypercholesterolemia and hypertriglyceridemia. There was a higher percentage of affected female patients with dyslipidemia compared with male patients. This predominance continued when risk factors such as obesity, poor glycemic control, duration and therapy of diabetes mellitus were considered. There is lack of awareness and treatment of dyslipidemic diabetic patients among practicing physicians in spite of the propagated knowledge on the decreased rate of coronary events and regression of atheroma in the vascular walls of the coronary arteries upon treatment of hypercholesterolemia. There is need to periodically screen the diabetic population and implement vigorous therapy for dyslipidemic ones.

Effect of gender, birth weight and gestational age on serum 17-hydroxyprogesterone concentration and distribution among neonates in Saudi Arabia.

Blood samples from 813 newborns were spotted on to filter paper and the 17-hydroxyprogesterone concentration was measured using the Delfia (R) fluorometric immunoassay. The median, mean, and standard deviation (SD) for the total population were 20, 21 and (11) nmol/L respectively. Males had significantly higher levels than females with median, mean and (SD) of 22, 22 and (12) nmol/L. Similarly, low birth weight babies were found to have significantly higher levels than normal birth weight babies with median, mean and (SD) of 21, 24 (12) nmol/L. Preterm babies were also found to have significantly higher levels than full term babies, with median, mean and (SD) of 25, 29 (16) nmol/L. As experienced elsewhere, those factors should be taken into consideration when considering a cut-off point in any neonatal screening program for congenital adrenal hyperplasia.

Population-based epidemiological study on characteristics of risk factors of hypercholesterolemia in Saudi Arabia.

OBJECTIVES To study the characteristics of risk factors for hypercholesterolemia among the Saudi population. DESIGN Population-based cross-sectional national epidemiological randomized household survey. SUBJECT 4548 Saudi subjects, aged 15 years and above. Sample was representative and in accordance with the national population distribution with respect to age, gender, regional and residency, urban vs. rural, population distribution. MEASUREMENT Height and weight with calculation of body mass index, blood samples were drawn and assayed for glucose and total cholesterol concentration. Hypercholesterolemia (HC) was defined: borderline high HC (5.2-6.2 mmol l-1) and high HC (> 6.2 mmol l-1). Univariate, multivariate, simple logistic, multiple logistic, odd ratio and chi-square were employed in the statistical analysis. RESULTS The risk of developing HC increased with age by 2% and 1% for each year increase in age for borderline high HC and high HC. The risk of developing HC was significantly higher among female subjects. There was no significant relation between the spectrum of BMI group, underweight to obesity, with risk of developing borderline high or high HC. There was a significant increase in the risk of developing HC among residents of urban communities. There was no significant regional variation for risk of borderline high HC, however, there was a significant increase in the risk of developing high HC among residents of Central and Eastern regions, compared with other regions. CONCLUSION The characteristics of risk factors for HC among the Saudi population differ in many respects from other populations. Overweight and obesity are not significant risk factors for HC. Rural communities are more at risk of HC than urban communities. The population of the Eastern and Central regions were at significantly higher risk of developing HC. The relatively recent urbanization may account for the low prevalence of HC. It may partially explain the dissociation between obesity and HC. Food habits, both in quantity and quality in rural communities in genetically predisposed homogenous populations may account for the increase in the prevalence of HC in rural communities. There is a need to propagate information about the potential health hazard of obesity and HC among Saudi communities, at large, and specifically in the Eastern and Central regions. There is a need to study the food patterns of rural communities which may explain partially the relative increase in the prevalence of HC in rural communities.

Serum total, fractionated cholesterol concentration distribution and prevalence of hypercholesterolemia in Saudi Arabia, regional variation.

This is a study of the regional variation in Saudi Arabia with respect to the pattern of distribution of total serum cholesterol concentration, low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol to HDL ratio (CH/HDL) and prevalence of hypercholesterolemia (HC) among Saudi population. It is a cross-sectional national epidemiological randomized household survey. The subjects consisted of 4548 Saudis over the age of 15 years. The sample was representative and in accordance with the national population distribution with respect to age, gender, regional and residency population distribution. Blood samples were drawn and assayed for total cholesterol concentration (TCC), triglyceride and high-density lipoprotein concentration. Low- density lipoprotein and total cholesterol/high-density lipoprotein ratio were calculated. The mean serum TCC of female subjects was higher than for male subjects across all regions; however, the difference reached a significance only in the Southern and Western regions. The 90th percentile of serum TCC for male subjects was either equal to or higher than that for female subjects at early age groups across all regions; however, the 90th percentile of serum TCC for female subjects was higher than for male subjects at older age groups across all regions. Mean serum HDL concentration for female subjects was either equal to or higher than for male subjects across all regions, except the Central region. The difference, however, reached a significance in the Western region only. The prevalence of borderline high HC (5.2 to 6.2 mmol/L) was higher among male subjects in the Central region and equal between male and female subjects of Western and Eastern regions and higher among female subjects in the Northern and Southern regions. The prevalence of high HC (>6.2 mmol/L) was higher among female subjects compared with male subjects across all regions. The highest and lowest prevalence of high HC among male subjects in the Eastern and Northern regions, respectively, while the highest and lowest prevalence of high HC among female subjects were in the Eastern and Northern regions. The prevalence of HC (>5.2 mmol/L) among subjects over the age of 40 years was highest and lowest for male subjects of Eastern and Southern regions, respectively, and for female subjects of Eastern and Western regions, respectively. There was a variable pattern of serum total and fractionated cholesterol concentration distribution among Saudi subjects. It appears, however, that at large, the subjects of the Eastern and Northern regions had the highest and lowest prevalences of cholesterol-related risk factors for CVD, respectively. There is a need to study the underlying factors for the regional variation with respect to cholesterol-related risk factors with emphasis on nutritional habits, including the quantity and quality of food, the prevalence of obesity, glucose intolerance and smoking. Identification of such factors is essential for monitoring the effectiveness of any future plan for combating cholesterol-related risk factors for CVD.