Prevalence of obesity, diabetes mellitus, and hypercholesterolemia in Saudi Arabia

In 1995 the Preventive Medicine Department of the Ministry of Health conducted a cross-sectional survey to estimate the prevalence of overweight, obesity, diabetes mellitus, and hypercholesterolemia. A probability sample of 13177 Saudi subjects over the age of 15 years (mean = 33 years) was selected to represent all regions of Saudi Arabia. General practitioners visited them at their houses and interviewed them. Subsequently each subject was examined and age weight and height were measured at the local primary health care center. A sub-sample of 4548 subjects (mean age = 33 years) were selected for measurement of serum cholesterol.

Overweight and obesity

Overall, females had a mean body mass index (BMI) of 26 compared to 25 for males and this slight difference was evident across all age groups. Having a BMI >= 25 (overweight or obese) was more common among females (51%) than males (45%). This difference was most evident in the obese category (BMI > 30) with 24% of females and 16% of males. In addition 2.2 % of females and 0.7% of males had morbid obesity (BMI > 40). The proportion of males (27%) and females (29%) in the overweight range BMI 25-30 was similar. BMI increased progressively with age for both sexes, reaching a maximum in the fifth decade of life. The difference between mean BMI for given age group and the men BMI for the consecutive age group was statistically significant between all the age groups, except for males and females aged 50 to 69. The higher prevalence of obesity and overweight among females was uniform across all regions of Saudi Arabia. Among females the highest prevalence of obesity was in the Northern Province (32%) and among males in the Eastern Province (23%). Far greater geographic differences were seen in comparing rural to urban populations. Of urban males, 18% fell into the obese category compared to 12% of rural males. Similarly, 28% of urban females were obese compared to 18% of rural females.

Impaired Glucose Tolerance (IGT) and Diabetes mellitus (DM)

Mean random blood sugar (RBS) concentrations were higher among males (5.4 mmol/L) than females (5.2 mmol/L) (p < .05 z-test). The male (mean RBS = 6.3 mmol/L) and female (mean RBS = 6.5mmol/L) residents of Northern region had the highest RBS in the country. Prevalence of IGT without DM was 10% for males and 9% for females (P=0.001). Prevalence of DM was 11.8% for males and 12.8% for females (P-0.001). The prevalence of DM progressively increased with age to 40% in the sixth decade of life. DM prevalence was highest (17.6%) in males in the Eastern region and females (18.6%) in the Northern region. The prevalence of IGT without DM was highest for males (12.3%) and females (9.9%) in the Central region.

The mean RBS concentration for urban males (5.7 mmol/L) and females (5.5 mmol/L) was higher (p<0.01 Z-test) than rural males (4.9 mmol/L) and females (4.9 mmol/L). Similarly, IGT without DM was more prevalent among urban males (10.9%) males and females (9.1%) than rural males ( 8.4%) and females (8.1%) (p<0.01 Z-test). DM was also more common among urban males (11.7%) and females (13.8%) than among rural males (6.8%) and females (7.4%) (p<0.01 Z-test).

Hypercholesterolemia (HC)

Females had a slightly higher mean serum cholesterol concentration (SCC) (4.25 mmol/L) than males (4.0 mmol/L). Twenty-one percent of females and 17.5% of males had mild HC (serum cholesterol 5.2-6.2 mmol/L) while 7.5% of males and 9.0% of females had very high cholesterol (>6.2 mmol/L). A progressive increase in the prevalence of HC with age was seen until the sixth decade of life. HC varied considerably by region with the lowest in the Northern region and the highest in the Eastern region. The mean SCC was significantly higher for both male (4.2 mmol/L) and female ( 4.3 mmol/L) residents of rural communities compared with male (3.9 mmol/L) and female (4.2 mmol/L) residents of urban communities.

This survey documents what may be the major threat to public health in Saudi Arabia over the upcoming decades[1,2). The prevalence rates for both obesity and DM are among the highest reported and in some groups (urban females) exceed rates seen in developed countries[3]. Currently, Saudi Arabia has a relatively young population. Since all these conditions increase with age, the magnitude of the problem will certainly increase in epidemic proportions.

Overweight, obesity, DM, and HC all cause irreversible, chronic changes which in turn lead to major chronic diseases including coronary artery disease, myocardial infarctions, cerebrovascular disease, cerebrovascular accidents, and chronic renal disease. These chronic diseases involve long hospitalizations and expensive specialized care and will place a mounting burden on the curative care services in Saudi Arabia over the upcoming decades.

A substantial multidiciplinary effort needs to be initiated to reverse the trend and lower prevalence of these precursor conditions plus others such as hypertension and tobacco abuse. This effort will require a substantial investment in community education and a far greater awareness by the public about the risks of these conditions. DM will need additional control through medical management and through identifying important cofactors such as hypertension for the progression to renal failure and other complications.

Special programs and other efforts to reduce the prevalence of obesity, DM, and HC will need assessment through follow-up surveys chronic disease surveillance, and registries (for DM, and vascular diseases). This will require appropriately equipped and staffed regional offices for chronic disease prevention and control. This survey serves as an important benchmark against which future data from these monitoring systems may be compared.