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 tu 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. Copyright (C) 1997 Elsevier Science Ireland Ltd.