1.1 Background of the study
Diabetes mellitus is defined as a metabolic disorder of multiple etiology characterized by chronic hyperglycemia with disturbances in carbohydrates , protein, and fat metabolism resulting from defects in insulin secretion ,insulin action or both (Alberti ,Defronzo,Keen,Zimmet.,1992). Llioja,Mott,Howard. (1988) reported that the presence of glucose circulating in the blood results in potential pathological complications.
Famuyiwa,Sulimani,Laajam,AL-Jesser,Mekki. (1992) reported that diabetes may present as an acute disorder with the classic triad of polyuria, polydipsia and unexplained weight loss, some patients may present for the first time in a coma. However, diabetes can also present as a sub acute condition over several months particularly in elderly patients in whom this triad is usually not so dramatic and may even be absent (Abdulkadir, 1993).
Scientists believe that a combination of genetic susceptibility and exposure to environmental factors cause increased incidence of this disease in individuals (Report of the Expert Committee on the diagnosis and classification of diabetes (1997).
Diabetes in addition to being a disease in itself is also a risk factor for coronary heart disease, myocardial infarction, angina and sudden death .It is a disease with specific complications (Mckeigue,Shah,Marmot:, 1991). Obesity is a major risk factor in diabetes mellitus (Alberti et al., 1992). Over 50% of patients with non insulin dependent diabetes mellitus (NIDDM) are obese (Ngwu, 2001)
Lyon,Vincce,. (1993) reported that most people with diabetes (more than 80%) die of cardiovascular disease. Diabetes doubles the risk of death from heart disease in women. Oldrizzi,Rugio,Mashio., (1994) reported that diabetes is classified into type 1 and type 2.It is a life long metabolic disease irrespective of the age of onset.
Type 1 diabetes mellitus also known as insulin dependent diabetes mellitus (IDDM) is an autoimmune disease which destroys the beta cells in the pancreas, the cell which produces insulin (Dietz, 1994). Bonnice (1998) reported that diabetes in childhood and adolescence is almost invariably type 1.The incidence is increasing in developed countries, while it is the subject of debate in Africa.
Type 2 diabetes mellitus also known as non-insulin dependent diabetes mellitus (NIDDM), is a multifactorial heterogeneous disorder characterized by chronic hyperglycemia as a result of two defects –insulin resistance (reduced insulin sensitivity) and β-cell dysfunction (impaired insulin secretion (World Health Organization (WHO), 1994).
Kashgari (2000) reported that type 2 diabetes mellitus starts much earlier many years before clinical diagnosis is made with a long period of insulin resistance and hyperglycemia. Ohwovoriole, Kuti ,Kabiawu., (1988) reported that diabetes mellitus affects about 1-7% of the Nigerian population and
over 90% of these are non insulin dependent, about the ages of 45 years and above.
King, Rewers., (1993) reported that a person is diabetic if after 2 hours of drinking a solution with 75 grams of glucose, blood glucose of more than 200 milligrams per deciliter (200mg/100 dl) is obtained. Blood glucose of below 140mg/dl indicates normal blood glucose status. Between 140-200mg/dl is an impaired glucose tolerance. Impaired glucose tolerance is a risk factor for developing diabetes, and also increases the risk of getting myocardial infarction. Morbidity and mortality from cardiovascular disease are two to five times higher in patients with diabetes compared with non-diabetes (American Diabetes Assoiation, 1994).
Diet plays an important role in the management of acute and chronic diseases such as diabetes mellitus (Mann, 1980). An important factor in the success of diabetes treatment is to know what and how much to eat, which food components gives calories and which directly influences blood glucose level (Robinson, Fuller, Edmeades., 1988).
Lebovitz (1994) reported that type 2 diabetes treatment begins with diet control, exercise and weight reduction, although over time this treatment may not be adequate. People with type 2 diabetes typically work with a dietitian to formulate a diet plan that regulates blood sugar level, so that it does not rise swiftly after meal (Price, 1999).
A recommended meal is usually low in fat, provide moderate protein (10-20% of total calories), and contains a variety of carbohydrates and vegetables (Yamanouchi,Westen., 1995). Barnard. (1994) reported that regular exercise help body cells absorb glucose ,thirty minutes of exercise daily can be effective. Diet control and exercise may also play a role in weight reduction which appears to partially reverse the body inability to use insulin.
Harum (1993) reported that western diet leads to apparent occurrence of non-infectious chronic disease such as colon cancer, coronary heart disease, diabetes and obesity.
1.2 Statement of the problem
Increasing affluence, urbanization and changing food habits have lead to high incidence of diet-related non-communicable diseases including diabetes, obesity and hypertension (Standing committee on Nutrition,(SCN),2006). Diabetes mellitus is becoming a major health problem in Nigeria with a high prevalence rate (The National Expert Committee on non-Communicable disease in Nigeria, 1992).Khare (1999) reported that though our understanding of diabetes has increased over time complication remain a problem. An individual who has diabetes is more likely to have obesity, hypertension, and coronary heart disease and stroke (Jervell, 1995).
More than 80% of people with diabetes mellitus die of cardiovascular disease. With diabetes the risk of death from heart disease in women doubles. (The Diabetes Control and Complication Trial Research Group (DCCTRG,1993). Arteriosclerosis tends to develop early in people with obesity who may also have hypertension. Atheroscleroic vascular disease especially coronary heart disease and stroke are the principal cause of death in about 70% of diabetic patients (ADA, 1994).
Morbidity and mortality from cardiovascular disease are two to five times higher in patients with diabetes compared with non diabetic.
The level of awareness is on the increase in the urban centers, however, the level of ignorance in rural areas is still very high; compliance to controlled diet is very low, especially in developing countries where poverty level and ignorance of complications resulting from uncontrolled diabetes is very high (Erasmus, Ebonyi, Fakeye., 1988).