Diet-related chronic diseases^[5]

Non-communicable diseases (NCDs) are the primary cause of mortality and morbidity in countries of the Eastern Mediterranean Region (EMR). NCDs are emerging as a major health problem in Egypt, where 41 percent of all deaths are caused by chronic diseases. As life expectancy increases and the elderly population continues to grow, chronic diseases will place an ever-greater burden on society (WHO, 2004).

This section provides a brief overview of trends in the major NCDs (hypertension, diabetes, CVD, cancer and osteoporosis) in Egypt over the last 20 years. Consecutive national surveys are lacking for most diseases, and available data spotlight only the present situation. Data sets on NCDs are shown in Annex 3, and in the tables and figures throughout this section.

Hypertension

Hypertension is considered a major risk factor for CHD, cerebrovascular disease and chronic renal failure. HPE-HES 1987 estimated that the overall prevalence of hypertension among Egyptians over six years of age was 15.8 percent. Systolic hypertension (above 150 mm Hg) was found among 11.3 percent, and diastolic hypertension (above 90 mm Hg) among 4.7 percent of Egyptians. Systolic hypertension was more frequent among urban residents (Said, 1987).

The National Hypertension Project (NHP) of 1995 estimated the overall prevalence of hypertension among Egyptians ³ 25 years of age at 26.3 percent (Figure 18). High systolic blood pressure (³ 140 mm Hg) was reported among 17.2 percent, while 13.9 percent had high diastolic blood pressure (³ 90 mm Hg). Hypertension increased progressively with age, and was slightly more common in women than men. However, younger age groups have shown progressive increases of hypertension over the past 20 years. The NHP results indicated that hypertension is highly prevalent in Egypt, and that awareness, treatment and control of hypertension are relatively limited (Ibrahim et al., 1995).

Adults with high normal blood pressure (130 to 139 mm Hg systolic blood pressure or 85 to 89 mm Hg diastolic blood pressure) are considered to be at high risk of developing hypertension; this group represented 17.5 percent of adults in 1995. The prevalence of hypercholesterolaemia and high levels of LDL-cholesterol was found to be higher among hypertensives than others (Ibrahim et al., 1995).

Preliminary data from a diet, nutrition and prevention of chronic NCDs survey (Ismail, 2005) showed that the crude prevalence of hypertension among adolescents aged ten to 18 years is 1.4 percent (Table 10), with higher prevalence in Upper Egypt than Lower Egypt for both types of hypertension. Females in rural areas reported the lowest prevalence rates of both systolic and diastolic hypertension, while females in urban areas reported the highest prevalence of diastolic hypertension, followed by males of both areas. Generally, males in all age groups had higher systolic hypertension than females (Figure 19), especially in the older age group (16 to 18 years). Females had higher diastolic hypertension, except for in the older age group where both genders were equal. Findings on adolescents with high normal blood pressure denoted that about one-quarter of Egyptian adolescents would develop hypertension over the following few years.

This case study uses studies of the status of hypertension among Egyptians covering the period from 1987 to 2005. They represent different age groups and use different cut-offs for hypertension, so it is not possible to derive trends from them.

Increasing prevalence of overweight and obesity among Egyptians constitutes a risk factor for hypertension. Increasing intakes of animal protein and low intakes of dietary calcium and magnesium probably contribute to the early development of hypertension in Egypt.

FIGURE 18
National estimate of hypertension among Egyptians aged 25 years and more, 1995

Source: Ibrahim et al., 1995.

TABLE 10
Status of systolic blood pressure and diastolic blood pressure by area and gender among Egyptian adolescents, 2005

¹ High normal blood pressure: 90th to < 95th percentile for age.
² High blood pressure: 95th to > 99th percentile for age.
Source: Ismail, 2005.

FIGURE 19
Hypertension prevalence among Egyptian adolescents by age group and gender, 2005

Source: Ismail, 2005.

Diabetes

Diabetes is considered a risk factor for CVD, renal impairment and blindness. In 1987, 1.3 percent of the people interviewed in a survey were aware that they had diabetes. Of these aware diabetics, 19.4 percent in both urban and rural areas were current smokers, and more male than female diabetics smoked. Regardless of area and sex, about half of the smokers smoked ten to 20 cigarettes a day (Said, 1987). In 1992, the overall prevalence of diagnosed diabetes among Egyptians over ten years of age was 4.3 percent, with higher rates among urban populations (Figure 20). Rural desert areas reported the lowest prevalence rate (Moursi, 1992).

In 1995, the combined prevalence of diagnosed and undiagnosed diabetes in the Egyptian population ³ 20 years of age was estimated to be 9.3 percent (Figure 21). Approximately half of these people were already known to have diabetes, while the other half were discovered to have diabetes during the survey; 9.6 percent had impaired glucose tolerance (IGT). IGT was more prevalent in rural than urban areas and in lower than higher socio-economic groups. As a group, diabetics represent the most obese segment of the population and have the highest WHRs (Hermann et al., 1995).

In 2005, the total prevalence of diabetes among children aged ten to 18 years was 0.7 percent (Table 11). The prevalence was higher among females than males, and equal in urban and rural areas. Children with fasting blood glucose (FBG) levels between 100 and 125 mg/dl were considered pre-diabetic; they represented 16.4 percent of the total sample. Males were more likely than females to be pre-diabetic. The rate differed according to age group, with the older age group (16 to 18 years) showing higher percentages for both sexes. Pre-diabetic males were equally prevalent in urban and rural areas, while there were more pre-diabetic females in rural than urban areas (Ismail, 2005). The high prevalence of pre-diabetic adolescents is an alarming signal for an increase in the incidence of diabetes among Egyptians in the future.

Increasing central obesity among adults (Shaheen, Hathout and Tawfik, 2004) and adolescents (Ismail, 2005) could partially explain the apparent increase in the prevalence of type-2 diabetes.

The National Diabetic Institute of Egypt, in collaboration with the Ministry of Health and Population (MOHP) and WHO, is carrying out a national survey on diabetes in Egypt. Data have not yet been published.

TABLE 11
Prevalence of diabetes and pre-diabetes among adolescents, by age and gender

¹ FBG ³ 126 mg/dl.
² FBG 100 to 125 mg/dl.
Source: Ismail, 2005.

FIGURE 20
Prevalence of diabetes by area at ten years of age and over, 1992

Source: Moursi, 1995.

FIGURE 21
Prevalence of diabetes by area and socio-economic status (SES) at 20 years of age and over, 1995

Source: Hermann et al., 1995.

Cardiovascular disease

In Egypt, the prevalence of CVD has multiplied over the last two decades. The possible causes of this increase are the progressive ageing of the population, urbanization, dietary changes, sedentary lifestyles, smoking and stress. Among elderly Egyptians, CVD is the most prevalent chronic disease, followed by rheumatic diseases and diabetes (Hassan et al., 2001).

In September 2000, the Egyptian Central Agency for Public Mobilization and Statistics (CAPMAS) released a report showing that CVD was responsible for 42.6 percent of all deaths. Hospital records of the reasons for admission to the cardiac department of Cairo University in 1984 and 1998 show that the prevalence of CVD increased from 6.9 to 32.9 percent over that period.

NHP data from 1991 to 1994 show that the following cardiovascular risk factors are more frequent in urban than rural Egyptians: hypertension, hypercholesterolaemia, low HDL-cholesterol, obesity, hypertriglyceridaemia, elevated LDL-cholesterol, increased fasting and post-prandial blood sugar, and cigarette smoking (Ibrahim et al., 1995).

The Lipid Profile among Egyptians (LPE) of 1997 to 1999 is Egypt’s first national survey of lipid profiles and ischaemic heart disease (IHD) based on a strict probability sample (Abdel-Aziz, 2000). Data from LPE reveal that risk factors varied among geographic areas, between urban and rural sites and between males and females. Lack of exercise and the threateningly high incidence of smoking should receive much attention from all health authorities. The apparently low incidence of smoking among females may not be reliable, as many women who smoke deny doing so. Results from LPE showed that 6 percent of men and 4.7 percent of women had IHD. Almost 40 percent of the whole population have cholesterol levels that are higher than the upper limit of normal (Table 12). There have been gradual increases in serum total cholesterol and LDL-cholesterol, which peak between the ages of 45 and 65 years, and a coincident decline in HDL-cholesterol (Abdel Aziz, 2000).

The Diet, Nutrition and Prevention of Chronic Non-Communicable Disease Survey (Ismail, 2005) is the first national survey to assess risk factors for the development of chronic diseases among Egyptian adolescents. Preliminary data from this survey indicate that the overall proportion of adolescents with high total cholesterol is 6.0 percent; the proportion with high LDL-cholesterol is 7.0 percent, with high triglycerides 7.8 percent, and with low HDL-cholesterol 40.0 percent (Table 13).

Increasing hypertension, diabetes and central obesity, in addition to dyslipidaemia, should be considered among the risk factors leading to the increase of CVD in Egypt. Decreased intakes of cereals over the last 20 years, with increased consumption of animal protein and trans fat and low intakes of omega 3 fat (Hassanyn, 2000), together with inactivity and smoking (Abdel Aziz, 2000) may all be co-factors for hypercholesterolaemia, which is a leading cause of atherosclerosis and vascular diseases.

TABLE 12
Distribution of total cholesterol, LDL-cholesterol and triglycerides among Egyptian adults

Source: Abdel Aziz, 2000.

TABLE 13
Distribution of total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides among Egyptian adolescents

Source: Ismail, 2005.

FIGURE 22
Numbers of cases of NCDs, 2001 to 2003

Source: National Centre of Health and Population Information, 2005.

FIGURE 23
Trend in CVD mortality rate in Egypt, 1973 to 1995

Source: National Centre of Health and Population Information, 2005.

FIGURE 24
CHD crude death rate by gender, 1990 to 1999

Source: CAPMAS, 2004.

Cancer

In developing countries, cancer is the third most frequent cause of death, after infectious diseases and diseases of the circulatory system; in developed countries it ranks second, after diseases of the circulatory system (WHO/FAO, 2003). Dietary factors account for about 30 percent of all cancers in Western countries, and for up to about 20 percent in developing countries; diet is second to tobacco as a preventable cause. Approximately 20 million people suffer from cancer; a figure that is projected to rise to 30 million within 20 years.

Since 1998, MOHP and the Middle East Cancer Consortium (MECC) have been sponsoring the National Cancer Institute (NCI), which is part of MECC’s Joint Cancer Registry. The NCI registry in Cairo is the largest hospital-based cancer registry in Egypt (GPCR Board, 2002).

According to NCI cancer statistics from 2003, the leading cancers in Egyptian patients are those of the breast, gastrointestinal tract, lymphoma and urinary bladder (Table 14). There is male predominance in cancer incidence, with a male-female ratio of 1.4: 1.0 (El-Bolkiny, Nouh and El-Bolkiny, 2005). The increasing prevalence of obesity among females is one of the reasons for increasing rates of breast cancer.

Liver cancer increased markedly from 0.2 percent in the mid-1970s to 7.5 percent in 2003, most probably owing to higher prevalence of hepatitis C infection. Observational data from NCI reveal that lung cancer is increasing, probably because of an increase in smoking. Mesothelloma (cancer of the pleura) is also increasing, which may be owing to asbestos inhalation.

Paediatric cancers are relatively common in Egypt and account for about 10 percent of all cancer cases. In 2003, the most common types of cancer among Egyptian children and adolescents up to 19 years of age where leukaemia (34 percent of cases) followed by lymphoma (17 percent of cases) (El Attar, in press).

TABLE 14
Most common diagnosed types of cancer, 1970 to 2003

TABLE 15
Most commonly diagnosed types of paediatric cancer, 1997 and 2001

Sources: NCI, Cancer Statistics, 1997; El Attar, in press.

FIGURE 25
Trends in cancer diagnosis among Egyptian adults, 1970 to 2003

Data obtained from: in-patient records, 1970 to 1985; pathology registry records, 1985 to 1989 and 1990 to 1997; hospital data base, 1997 to 2001 and 2002 to 2003.

Sources: Sherif and Ibrahim, 1987; Mokhtar, 1991; El-Bolkiny, Nouh and El-Bolkiny, 2005; NCI, Cancer Statistics, 2002; El Attar, in press.

Osteoporosis

Osteoporosis is a disease of progressive bone loss associated with an increased risk of fractures. The disease often develops unnoticed over many years, with no symptoms or discomfort until fractures occur (AAOS, 2000). Diagnosis of osteopenia and osteoporosis in this case study is based on WHO 1994 classifications. Data from NNI national surveys to determine bone mass density (BMD) among adolescents and adults in 2004 (Table 16), and among the elderly in 2001 revealed that osteoporosis is a major health problem in Egypt.

About half of male adolescents (aged ten to 19 years) and more than one-quarter of females in the same age group were relatively osteopenic. The prevalence rates of relative osteoporosis were 16.7 and 0.9 percent for males and females, respectively, with no statistical difference between urban and rural areas. There was a statistically significant difference between male and female adolescents, but as age advanced the bone status of male adolescents improved, so that by the age of 18 years only 13 percent still had relative osteopenia. It is reported that nearly 70 to 80 percent of adult BMD is attained by the age of 18 years (Hassan, Abdel Galil and Moussa, 2004).

In the 40 to 50 years age group, 42 percent of females and 43 percent of males had low BMD. At the age of 60 years, about half of the males had osteoporosis, and half of the females had osteopenia, while a third of the elderly population (65 to over 80 years of age) are osteoporotic (Hassan, Abdel Galil and Moussa, 2001).

The unexpectedly high prevalence of low BMD among Egyptians, especially adult men, could be explained by increased smoking, reduced physical activity and increased consumption of soft drinks, in addition to low calcium intake, low omega 3 fat in diets and increasing animal protein intakes.

TABLE 16
Prevalence of osteopenia and osteoporosis among adults, by age and gender

¹ BMD > 1 -< 2.5 SD reference mean.
² BMD ³ 2.5 SD reference mean.
N.B. Osteopenia and osteoporosis are relative in adolescents.
Source: Hassan, Abdel Galil and Moussa, 2004.