CHAPTER ONE
1.0 INTRODUCTION
1.1.0 BACKGROUND
Diabetes mellitus is a chronic disease whose current global spread has the characteristics of a pandemic
. Dr Awokola Babatunde, a Family Physician in Wesley Guild Hospital, Ilesa Nigeria diagnosed 21 new diabetic patients with ages ranging between 32 and 45 years within 3 months of consulting in the Family Medicine clinic
. He felt that they were randomized to his consulting room by chance until four other colleagues in his clinic made him realize that they had noticed a similar trend in their consulting rooms
. Mobile phone enquiries confirmed a similar trend in
Lagos, Ibadan, Benin, Ilorin, Ghana (Accra), South Africa (Pretoria), and Mali (Bamako).
Diabetes mellitus is here with us, and if the current trend of rapid westernization of African societies continues, it will be with us for a long time to come
. The importance of good health policy implementation is well demonstrated by the fact that health issues dominate the eight Millennium Development Goals (MDG) set by the United Nations (UN) to be achieved by the year 2015. Although diabetes mellitus falls within ‘other disease’, without specific mention in the sixth goal, it is important to know that of the 200 million people with diabetes globally, 60% will die of cardiovascular diseases, and 40% will die of kidney diseases. This puts diabetes mellitus ahead of HIV/AIDS and malaria in morbidity and mortality. Yet the problem is not well recognized (1) . The International Diabetes Federation (IDF) and World Health Organization (WHO) have stressed the need for nations to formulate and implement prevention plans for diabetes mellitus. 3,4 Studies done in the past, (both cross-sectional and longitudinal) have identified a number of risk factors for type 2 diabetes. The modifiable risk factors include abdominal obesity, excessive alcohol ingestion, poor dietary habits and physical inactivity. The Non modifiable risk factors include age and genetic predisposition.
According to Dr J Jervell, President of the International Diabetes Federation, ‘As populations in the developing countries enhance their economic demand, they tend to seek out many of the lifestyle traits of Western society that we now accept as causally linked factors in non-communicable diseases.
In the United States, a new diabetes patient is diagnosed every 50 seconds.
In the year 2000, the prevalence of diabetes mellitus in the WHO African Region was estimated at 7.02 million people, out of which about 0.7 million (10%) had type 1 diabetes mellitus and 6.3 million (90%) had type 2 diabetes mellitus.
About 113 100 people (1.6%) in the same report died
from diabetes related causes, 561 600 (8%) were permanently disabled, and 6 458 400 (92%) experienced temporary disability. These figures are quite outdated and a recent account of non- communicable chronic diseases (NCCDs) revealed that Nigeria is one of Africa’s leading countries with regard to the highest number of people suffering from diabetes mellitus.
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Also, the trend of type 2 diabetes mellitus in children is on the increase with death due to diabetes mellitus projected to increase by 52% by the year 2015.
The major risk factors for type 2 diabetes in Sub-Saharan Africa are similar to those in other regions of the world, whether this refers to the modifiable or non modifiable risk factors. It is obvious we have a situation in our hands. Frontline physicians need to acquire more competence in the management of diabetes mellitus to cope with this coming avalanche because endocrinologists cannot do it alone. The rising prevalence of type 2 diabetes in the region has largely been ascribed to changes in lifestyle and urbanization. However obesity has traditionally been uncommon in many parts of the region, largely owing to scarcity of food and high levels of energy expenditure. Cultural perception of body size is an important concern as in many of these countries a large body size might be associated with attractiveness, health and happiness. A study by Martorell et al
on obesity in women, that listed 18 countries of Sub- Saharan Africa, found that only 1.0 - 7.1% of the women aged 15 - 45 years of age in these Sub-Saharan African countries were obese - as defined by a Body Mass Index (BMI) > 30.0 - yet at the same time, 31% of South African women were obese
. The relationship between lifestyle and the prevalence of type 2 diabetes mellitus, and how this lifestyle modification among the Nigerian population compares to lifestyle in western developed countries is yet to be determined and documented. Therefore, action on risk factors that can be modified through individual, family and community health education and environmental
interventions could be instituted. Efforts to prevent type 2 diabetes and its complications in Africa should be similar to those in the rest of the world. As elsewhere, the potential for intervention in disease development exists because many of the risk factors are modifiable. Moreover, the potential for improvement in outcome is indicated by the disproportionate mortality associated with acute metabolic and infective causes, cardiovascular and kidney disease.
The success of prevention strategies in Africa is still subject to the variability of existing health care at all levels both within and between countries
. Studies conducted in India in the last decade have highlighted that not only is the prevalence of type 2 diabetes high, but also that it is increasing rapidly in the urban population. An urban-rural difference in the prevalence rate was found, indicating that the environmental factors related to urbanization had a significant role in increasing the prevalence of type 2 diabetes
. These findings were further supported by the study done by Boddula et al
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that reported a prevalence of diabetes of 21.2% and impaired Glucose Tolerance (IGT) rate of 18.2% in an urban high socio-economic group in India. In countries that are currently industrializing, the highest rates of diabetes are found in higher socio-economic groups. Reasons for this include increasing obesity related to changes in diet, reduced physical activity and although the data from India seem scarring, the result from the study certainly seems to support this trend
. Although the prevalence of type 2 diabetes is four – six times higher in urban populations in India, than in the rural areas, the number of people with IGT is high (7-8%) even in the rural population, which may indicate the presence of a genetic basis for type 2 diabetes in this ethnic group
. The prevalence of type 2 diabetes in Mexico has increased in recent years by close to 25% over an 8 year period (2000-2008). It is difficult to compare individual surveys due to different diagnostic methods. If the same diagnostic criteria are used,
prevalence will increased from 6.1 to 8.3%. In 2000, National health survey analyses that adjust for the differences caused by diagnostic methods were included, and it was estimated that the prevalence could be as high as 12%. These data re-enforce the urgent need for diabetes prevention. A rise in the estimated prevalence of type 2 diabetes among rural Kenyans in just four years (2003- 2007) have led to the suspicion that there could have been aspects of lifestyle change amongst rural Kenyans that has exposed them to the disease more
. A factor that contributed to significantly higher incidence of type 2 diabetes compared to non diabetics of the same age and gender included a significant period of childhood starvation. Children born small for gestational age due to intrauterine growth restriction, and who remained short are characterized by insulin resistance are at risk for type 2 diabetes mellitus
. Birth weights, though contemplated in the study could not be established for this population that was elderly and mostly born at home. The Leningrad study which studied the effects of starvation in utero and infancy is the only literature that investigated the relationship between childhood starvation and type 2 diabetes
. Abdominal obesity presented a twofold risk of developing type 2 diabetes mellitus in female participants. Although general obesity has been reported as a major risk for type 2 diabetes, intra abdominal adipose accumulation has been found to be the key correlate to the metabolic syndrome 18 –21. The metabolic syndrome is a cluster of metabolic abnormalies that has been observed to pre-dispose one to cardiovascular disease and type 2 diabetes mellitus. These include individuals being atherogenic, prothrombotic, hypertensive; they had dyslipidaemia; inflammatory metabolic changes and impaired glucose tolerance
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. Diabetes reported in a first degree relation led to a doubling of risk of type 2 diabetes in the study population. Diabetes type 2 in siblings and members of the nuclear family was reported in previous studies 22-24 . Family history of type 2 diabetes is not only a risk factor for the disease, but could be
used positively for risk awareness and risk reducing behavior. Dietary and social habits were also studied. A diet composed of high quantities of animal protein and refined starch has been associated with increased risk for type 2 diabetes mellitus 25-27 although the level of physical activity was not determined in the said population. Physical inactivity and significant alcohol consumption is a risk factor for type 2 diabetes mellitus and has been reported in other studies
.
1.1.1 BRIEF HISTORICAL BACKGROUND
Diabetes mellitus is a disease which was recognized in antiquity
. The Ebers papyrus, dating from about 1550 BC, testifies to the long history of diabetes. This papyrus found in a grave in Thebes in 1862 and named after Georg Ebers, contained description of various diseases, including a polyuric state resembling diabetes mellitus
. The term “diabetes” which is Ionian Greek and means “to run through” or a ‘siphon’ was first used by Aretaeus of Cappadocia (81- 133AD) in the 2nd century AD as generic description for conditions causing increased urine output
. Similarly, the Roman physician Galen (131-201AD), like Aretaeus, thought diabetes to be a rare disease. He employed an alternative term for diabetes including ‘diarrhoea urinosa’ and ‘dipsakos’, the latter emphasizing the cardinal symptoms of excessive thirst and drinking
. Two notable Indian physicians, Susruta and Charuka in the 5th century AD associated polyuria with a sweet tasting substance in the urine. Indian description of that time appeared to distinguish two forms of diabetes, one affecting older fatter people and the other thin people who did not survive long. Later in the 17 th century, the word mellitus (honey sweet) was added by Thomas Willis (1621 – 1675) after discovering the sweetness of urine and blood of patients with diabetes. Matthew Dobson, later in the 18 th century AD (1776) determined that diabetes serum was sweet to taste and contained sugar
. An important milestone in the history of diabetes mellitus is the establishment of the role of the liver in glycogenesis and the concept that diabetes mellitus is due to excess glucose production
proposed by Claude Bernard (France) in 1857.
The role of the pancreas in pathogenesis of diabetes mellitus was discovered by Mering and Minkowski (Austria) in 1889 and the hypothetical pancreatic glucose lowering hormone ‘insulin’ was proposed by Jean de Meyer early in the 20 th
century
. This led to the isolation of hypoglycaemic extract from the pancreas. Insulin was finally isolated by Frederick Banting and Charles Best (Ontario Canada) in 1921.
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Trials to prepare an orally administered hypoglycemic agent ended successfully with the marketing of Tolbutamide and Carbutamide for people with type 2 diabetes mellitus in 1955. Roger Hinsworth had earlier discovered there were two types of diabetes mellitus in 1935. In the 1960’s, urine strips were developed by Dorothy Frank and the first portable glucometer was created in 1969 by Ames Diagnostics. In 1979, the haemoglobin A1C test was devised in order to create a more precise blood sugar measurement, and is used to track glucose changes over a period of four months, the life span of the cell. 28,29
In May of 1995, Metformin, an oral medication for people with type 2 diabetes mellitus was finally approved for use by the FDA.
Three thousand years have passed since Aretaeus spoke of diabetes as a ‘mysterious sickness’, it has been a long and arduous process of discovery, as generations of physicians and scientists have added their collective knowledge to finding a cure.
1.2 STATEMENT OF PROBLEM
Type 2 diabetes mellitus is a chronic incurable disease associated with significant morbidity and mortality. According to research by Kenyan diabetes experts, published in the East African journal, Kenya’s prevalence of type 2 diabetes has now surpassed the WHO estimate of between 1% and 6%; with incidence being as high as 14% in urban areas
. Type 2 diabetes is rapidly increasing in
prevalence worldwide, particularly so in developing countries which are least able to cope with this complex and serious disease
. Shortage of insulin, other hypoglycaemic agents, monitoring and laboratory facilities and trained staff all contribute to serious short falls in the care of patients with diabetes mellitus in resource poor countries
. These factors potentially lead to poor glycaemic control and a high burden of complications 31. Over the past 30 years, the prevalence of diabetes has been increasing steadily in Nigeria. In 1971, a hospital survey by Osuntokun et al
in Ibadan estimated a prevalence of 0.4%; in 1989, while screening for diabetes during a World Diabetes Day (November 14) in Lagos metropolis, Ohwovoriole et al
found a prevalence of undiscovered diabetes of 1.6%. A national survey in 1992 by the Non Communicable Disease Expert Committee of the Federal Ministry of Health recorded a National prevalence of 2.2%, lowest was 0.5% in Mangu, Plateau State and highest was 7% in Lagos Island. A survey in Jos by Puepet in 2004 recorded a prevalence of 10.3%
. The progressive increase in the prevalence rates of type 2 diabetes is associated with lifestyle changes, overweight and obesity, physical inactivity, alcohol consumption, and smoking - factors that are potentially modifiable. Patients’ with type 2 diabetes mellitus are at risk of varying complications. Risk of micro and macro vascular complications, such as myocardial infarction, stroke and peripheral vascular disease, are common causes of morbidity and premature mortality
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. This is also a primary cause of increase in the frequency of job layoffs, premature retirement, blindness and kidney failure in Sub Saharan Africa and the sub tropics. Type 2 diabetes mellitus has become an important public health concern particularly with rising chronic complications. The consequences of poorly managed type 2 diabetes is early development of complications which pose a lot of management challenges given that the resources needed to
manage these complications are enormous and scarce. This is so in Nigeria, where there is a double burden posed by Malaria and HIV/AIDS, and other non communicable diseases like hypertension.
Solagberu et al
in Ilorin and Ogunlade et-al
showed that diabetes mellitus is the second leading cause of amputation after trauma, responsible for 29% and 26% respectively. Nwosu
in Nnewi reported that type 2 diabetes is responsible for bilateral blindness in 18% of diabetic patients attending the eye clinic while Chuhwak et al
in Jos in a study of type 2 diabetes had found that 70.1% of these patients had hypertension
. These complications further create fear, anxiety and loss of productivity among the patients. The complications aforementioned contribute substantially to the health care cost: An estimated US$92 billion plus another US$40 billion indirectly related to diabetes due to loss of productivity (from lost work days, lost home services, permanent disability and premature mortality) making a total cost of US$132billion as calculated by the American Diabetes Association
. The market for diabetes medicines and diagnostic tests in Kenya will hit US$26.8 million in the next four years according to a report
. The treatment of one insulin requiring diabetic patient (type 2 diabetic patients may eventually require insulin) in a developing country may deprive 75 others of potentially lifesaving anti-malarial and antibiotics
. A study by Enwerem et al
on prescription and cost consideration at a diabetic clinic in Ibadan Nigeria, reported N185.5/day cost. With an average 3 months hospital stay on each admission, it is unlikely that most of the patients will be able to sustain their supply and therefore the adherence to therapy. Nigeria’s per capita income in 2005 of $560 reflects the low spending power of the population and therefore the management of diabetes
. Furthermore, diabetes mellitus is the third leading cause of end stage renal disease (ESRD) in Nigeria
. Diabetes mellitus has been found to be a cause of
erectile dysfunction, and this is of great interest to the Family Physician
. At diagnosis nearly 40% of people with type 2 diabetes mellitus have evidence of retinopathy and after 6 years the figure has risen to 62%.
Therefore the need for identifying these risk factors so as to facilitate prevention, early diagnosis and treatment cannot be over emphasized
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.
1.3 RATIONALE FOR THE STUDY
Identification of risk factors lies at the heart of clinical efforts to reduce the prevalence and eventual complications of type 2 diabetes. When multiple risk factors occur in a single individual, risk is compounded, justifying efforts to estimate global risk
. Evidence based medicine demands that management strategies are based on hard evidence and from the above there is a real need, albeit theoretical, for diabetics especially type 2 to pay attention to health
. In the past few decades, significant changes have occurred in the pattern of health and disease in many developing countries including Nigeria. As malnutrition and communicable diseases come under control, with resultant increase in life expectancy and with progressive urbanization and industrialization, non communicable chronic diseases (NCCD) like diabetes mellitus and hypertension have emerged as major public health problems
. Type 2 diabetes progresses through the stages of normal glycaemia to impaired glucose tolerance, and with multiple risk factors compounding before overt diabetes. This provides a potential ‘window period’ for intervention in high risk groups and these interventions may postpone or delay the onset of type 2 diabetes and its associated multi system complications
. Preventing type 2 diabetes is even more important because the patient with type 2 diabetes with or without symptoms has an increased prevalence of both micro and macro vascular complications at time of diagnosis 1,31,34,39,47 . First degree relatives of persons with type 2 diabetes are at high risk of developing the disease and preventive efforts can be directed towards them. 23,33,34,39 There is no
study done in the past in PSSH Jos to determine the prevalence of these risk factors. It is therefore important to undertake a study on the risk factors for type 2 diabetes mellitus, in order to help formulate preventive measures, and to improve the quality of life of the people.
1.4.0 AIMS AND OBJECTIVES OF THE STUDY
1.4.1 GENERAL
To determine the risk factors for type 2 diabetes mellitus among patients attending the outpatient clinics in Plateau State Specialist Hospital Jos, for the purpose of prevention, early diagnosis and education of clients, including the public.
1.4.2 SPECIFIC
i. To investigate and identify the common variables that were different in diabetics as compared to non diabetics and whether these could be risk factors for type 2 diabetes mellitus. ii. To determine the risk factors that could be responsible for the rise in the prevalence of type 2 diabetes mellitus by comparing findings with those of previous literature.
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