Browsing by Author "Amoah, A.G."

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Aetiology of heart failure as seen from a National Cardiac Referral Centre in Africa
(Cardiology, 2000) Amoah, A.G.; Kallen, C.
572 consecutive patients with heart failure referred to the National Cardiothoracic Centre, Accra, Ghana, over a 4-year period were evaluated for the aetiology of heart failure using two-dimensional Doppler echocardiography with colour flow. The mean age of the subjects with heart failure was 42.3 ± 0.9 years. The male to female ratio was 1.2:1.0. Combined heart failure was seen in 50.5% of subjects. Peak incidence of heart failure occurred in the 5th decade. The main causes of heart failure were hypertension (21.3%; n = 122), rheumatic heart disease (20.1%; n = 115) and cardiomyopathy (16.8%; n = 96). Congenital heart disease and coronary artery disease accounted for 9.8 and 10% of cases, respectively. The commonest rheumatic valvular lesion was mitral regurgitation (78%). Dilated cardiomyopathy was the commonest form of idiopathic cardiomyopathy (67.7%; n = 65). Endomyocardial fibrosis and hypertrophic cardiomyopathy accounted for 22.9% (n = 22) and 9.4% (n = 9), respectively, of cardiomyopathies.
Body size and blood pressure: an analysis of Africans and the African diaspora
(Epidemiology, 2008-01) Cappuccio, F.P.; Kerry, S.M.; Adeyemo, A.; Luke, A.; Amoah, A.G.; Bovet, P.; Connor, M.D.; Forrester, T.; Gervasoni, J.P.; Kaki, G.K.; Plange-Rhule, J.; Thorogood, M.; Cooper, R.S.
BACKGROUND: Blood pressure is directly and causally associated with body mass index (BMI) in populations worldwide. However, the relationship may vary across BMI in populations of African origin. METHODS: We compared the relationship between blood pressure and BMI in populations of African origin, using 13 samples from Africa, the Caribbean, the United Kingdom and the United States. We had access to data from individual participants for age, height, weight, blood pressure, and treatment of hypertension. Analysis was restricted to 18,072 participants (age 35-64 years; 44% men). We carried out multivariate regression analysis to estimate the relationship between blood pressure and BMI by country and by sex. The use of antihypertensive treatment was taken into account by exclusion and by sensitivity analysis. RESULTS: There was a positive relationship between both systolic and diastolic blood pressure and BMI. In men the slopes for systolic blood pressure varied from 0.27 mm Hg per kg/m (95% confidence interval = -0.01 to 0.56) in the United States to 1.72 mm Hg per kg/m (95% confidence interval = 0.92 to 2.53) in Ghana (Kumasi). In women, the slopes varied from 0.08 (-0.54 to 0.72) in South Africa to 1.32 (0.98 to 1.66) in the Republic of Congo. Similar variation in trends was seen for diastolic blood pressure. The higher the BMI, the shallower the slopes [-0.10 (-0.15 to -0.06) for systolic, -0.09 (-0.12 to -0.06) for diastolic]. No differences were seen after excluding persons who were being treated for hypertension. CONCLUSIONS: Blood pressure and BMI levels vary among populations of the African diaspora. The effect of BMI on blood pressure levels diminishes as BMI increases. These results suggest a complex relationship among excess body weight, adiposity, and energy expenditure.
Cardiovascular complications of diabetes mellitus in sub-Saharan Africa
(Circulation, 2005-12) Kengne, A.P.; Amoah, A.G.; Mbanya, J.C.
Background - Cardiovascular disease, the major cause of mortality and morbidity in modern societies, is set to overtake infectious diseases in the developing world as the most common cause of death. The increasing prevalence of major and emerging cardiovascular risk factors accounts for the growing burden of cardiovascular disease in the world. Diabetes in all its forms is one of the main cardiovascular risk factors. Two of 3 diabetic patients will die as a result of cardiovascular complications, and approximately 30% of patients treated in cardiovascular intensive care units have diabetes. Methods and Results - This review on the cardiovascular complications of diabetes in sub-Saharan Africa is a bibliographical MEDLINE search of published data over the past 2 decades. Diabetes-related cardiovascular disease complications are considered to be rare in Africa but are on the rise and are regularly associated with classic cardiovascular risk factors. Coronary heart disease may affect 5% to 8% of type 2 diabetic patients and cardiomyopathy, up to 50% of all patients. Close to 15% of patients with stroke have diabetes, and up to 5% of diabetic patients present with cerebrovascular accidents at diagnosis. Peripheral vascular disease prevalence varies across sites from 4% to 28%. Conclusions - It is obvious that diabetes mellitus and related cardiovascular complications are gaining more importance in sub-Saharan Africa. The relative contribution of putative risk factors is not well defined, and further research is therefore needed. © 2005 American Heart Association, Inc.
The changing patterns of hypertension in Ghana: A study of four rural communities in the Ga District
(Ethnicity & Disease, 2006-09) Addo, J.; Amoah, A.G.; Koram, K.A.
Objective: To determine the prevalence, distribution and risk factors of hypertension among rural residents in Ghana. Design and Setting: Cross sectional study in four rural communities in the Ga District of Ghana. Subjects and Methods: All adults aged $18 years in four rural communities were asked to participate. The average of two blood pressure readings taken with a mercury sphygmomanometer after 10 minutes of rest was used in the analysis. Hypertension was defined as blood pressure ≥140/90 mm Hg. Results: 362 subjects with a mean age of 42.4 ± 18.6 years participated in the study. The prevalence of hypertension was 25.4%. Of those with hypertension, only 32.3% (n=30) had prior knowledge of their condition, and less than half of these (n=12) were on treatment. Of those on treatment 16.7% were well controlled (blood pressure ≤140/90 mm Hg). The adjusted odds ratios for developing hypertension for overweight or obesity were 5.8 (95% confidence interval 1.4-24.3) and 6.9 (95% confidence interval 1.7-28.2), respectively. The adjusted odds ratio for hypertension for age groups 45-54, 55-64, and ≥65 years were 31.9 (95% confidence interval 1.88-539.11), 31.8 (95% confidence interval 1.6-624.2), and 58.8 (95% confidence interval 2.9-1168.7), respectively. The adjusted odds ratio for hypertension with respect to smoking, alcohol consumption, job-related physical activity, family history, education, occupation, and diabetes status did not attain statistical significance. Conclusion: Hypertension is now of public health significance in rural Ga District of Ghana. The high rate of hypertension was associated with low levels of awareness, drug treatment, and blood pressure control. Overweight and obesity are modifiable risk factors for hypertension that can be addressed through lifestyle interventions. Additionally, integrating hypertension care into primary care in rural health facilities may prove beneficial.
Current trends in the incidence of cerebrovascular accidents in Accra.
(West African Journal of Medicine, 1994) Nyame, P.K.; Bonsu-Bruce, N; Amoah, A.G.; Adjei, S.; Nyarko, E.; Amuah, E.A; Biritwum, R.B.
The incidence of cerebrovascular accidents (CVA) in Accra during three periods--1960-1968, 1976-1983, and 1990-1993, was compared. There was dramatic increase in the incidence between 1990-1993. Uncontrolled hypertension due to non-compliance with drug therapy seems to be the main cause. The economic plight of the people may explain the non compliance. The case fatality was between 41.9% to 50.3% for the years 1990-1993. Cardiovascular diseases, notably hypertension and CVA, have become the major causes of morbidity and mortality in Accra.
Diabetes in Ghana: a community based prevalence study in Greater Accra
(Diabetes Research and Clinical Practice, 2002) Amoah, A.G.; Owusu, S.K.; Adjei, S.
Data on the prevalence of diabetes in Ghana is scanty and unreliable. In the present study we have ascertained the prevalence of diabetes, impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT) in a random cluster sample of Ghanaians aged 25 years and above from the Greater Accra area of Ghana. Diabetes, IFG and IGT were defined by criteria of the American Diabetes Association and World Health Organization. The mean age of the 4733 subjects involved in the study was 44.3±14.7 years, and participation rate was 75%. The crude prevalence of diabetes was 6.3%. Out of 300 subjects with diabetes, 209 (69.7%) had no prior history of the disease. Diabetes, IGT and combined IFG and IGT increased with age. The oldest age group (64+ years) had the highest diabetes prevalence (13.6%). The age-adjusted prevalence of diabetes, IFG and IGT, were 6.4, 6.0 and 10.7%, respectively. Diabetes was more common in males than females (7.7 vs. 5.5%) [P<0.05]. Worsening glycaemic status tended to be associated with increase in age, body mass index, systolic and diastolic blood pressures. Ascertainment of predictors for diabetes in Ghanaians and the significance of the relatively high rates of and IFG and IGT however, remain to be determined.
Endemic goitre and urinary iodine levels in rural communities in the Bolgatanga and Builsa districts of the upper east region of Ghana
(East African Journal of Medicine, 1998-09) Asibey-Berko, E.; Amoah, A.G.; Addo, F.; Agyepong, E.
Objective: To ascertain the severity of IDD in some rural communities in upper east of Ghana and to urge the establishment of intervention and control measres for IDD. Subjects and study design: A total of 1061 subjects, made up of about an equal number of children (8-14 years) and women of childbearing age (15-45 years) from seven Sekoti villages and five Builsa villages of the upper east of Ghana were examined for goitre by the palpation method. In addition, every tenth subject examined, provided urine for urinary iodine determination. Results: 68.8% of the subjects had goitre; 9.9% had visible goitre. The goitre rates of the children from Builsa (77.2%) were significantly higher than those from Sekoti (59.1%) [z=4.5; p<0.001]. The overall prevalence of goitre and visible goire in women in the two areas were 70.8% and 15.4% respectively. The women of Sekoti had more goitres (76.6%) but less visible goitres (8.8%) than those of Builsa (63.5% and 21.9%) [p<0.001). The median urinary iodine level for the two survey areas was 1.6 μg/dl. 72% of subjects and urinary iodine less 2 μg/dl/ 24% had urinary iodine levels in the range 2-5 μg/dl and the remainder had urine iodine in the range 5-10 μg/dl. Conclusions: These findings indicate severe IDD in Sekoti and Builsa areas requiring urgent action. Further studies are indicated to determine the cause(s) of the IDD endemia.
Facilities and resources for diabetes care at regional health facilities in southern Ghana
(Diabetes Research and Clinical Practice, 1998-11) Amoah, A.G.; Owusu, S.K.; Saunders, J.T.; Fang, W.L.; Asare, H.A.; Pastors, J.G.; Sanborn, C.; Barrett, E.J.; Woode, M.K.A.; Osei, K.
In the fall of 1995, each of the five provincial hospitals in southern Ghana was visited and facilities and resources for diabetes care assessed. In addition, health facilities and standards of care questionnaires were completed. Only Korle Bu Teaching Hospital run a diabetes clinic and had diabetologists. Only two facilities had an eye specialist or trained dietician. None of the five facilities had a trained diabetes educator or chiropodist. Except for sphygmomanometers, basic equipment for clinical care were lacking. Basic biochemistry tests were available at all facilities. Creatinine clearance and 24-h urine protein, glycated haemoglobin, fasting triglyceride, total cholesterol and HDL cholesterol were available at only one centre. None of the facilities measured C-peptide, islet cell antibody and urine microalbumin. None of the facilities had chronic haemodialysis service. Insulin supply was erratic at two institutions. Three regions had active diabetes associations. The facilities and system of diabetes care in southern Ghana revealed in this study are far from satisfactory. Training of health care personnel in diabetes management and education may enhance diabetes care despite the existing constraints. Furthermore, the development of international and regional gradelines for facilities and resources may facilitate implementation of international resolutions and clinical practice guidelines.
Feasibility of thyroid ultrasonography in field studies in a developing country, Ghana.
(2004-06) Amoah, A.G.; Asibey-Berko, E.; Ayettey, O.M.; Addo, F.; Agyepong, E.; Lartey, A; Ndanu, T.A.
This study was carried out to determine the feasibility of using ultrasonography for goitre estimation in the field situation. It is a cross sectional study that was conducted using community based cluster sample. Thyroid sonography was performed on 112 randomly selected school children aged 10 -15 years from two districts in the Greater Accra area of Ghana, using normative values for thyroid volume recommended by WHO/ICCIDD. The mean age of all subjects was 13.5 years+/-0.13 SEM. The male to female ratio was 1:1. The mean height and weight of the children were 1.5 metres+/-0.9 SEM and 38.1 Kg+/-0.7 SEM, respectively. The mean body surface area was 1.27 m2+/-0.2. There were no significant gender differences in their ages (13.6yrs+/-0.2 SEM, 13.4yrs+/-0.1 SEM, respectively) and height (1.50m+/-1.6 SEM, 1.46m+/-1.7 SEM, respectively). The girls (40.0kg+/-1.2 SEM) weighed more than the boys (35.6kg+/-1.1). The mean and median urinary iodine concentration were 82.4+/-8.5 SEM and 67.9 ug/l, respectively. All the children examined had normal thyroid sonogram. The thyroid volumes ranged from 3.6 ml to 15.3ml. The mean thyroid volume was 7.0ml+/-0.2 SEM and the thyroid volume was higher in the girls (7.5ml+/-0.3 SEM) than the boys (6.5ml+/-0.2 SEM). The criteria of thyroid volume per age and sex yielded a goitre prevalence of 1.8 %. In contrast, the criteria of thyroid volume by surface area yielded a goitre prevalence of 8 %. Our study has shown that it is feasible to employ ultrasonography for field studies to determine goitre prevalence in school children in a developing country such as Ghana. However, the best criteria for goitre in children in Ghana, requires to be confirmed in future studies.
Further studies on the pharmacokinetics of perhexiline maleate in humans
(Xenobiotica, 1986) Amoah, A.G.; Gould, B.J.; Parke, D.V.; Lockhart, J.D.F.
1. We have performed single-dose pharmacokinetic studies on perhexiline in eight young volunteers, each given 300 mg of Pexid orally, using an h.p.l.c. method for the separation and quantification of the drug and its monohydroxy metabolites in plasma and urine. 2. The plasma concentration of the cis-monohydroxyperhexiline (peak of 473 ± 43 ng/ml at 7.5 ± 2.0 h) was always higher than for unchanged perhexiline (peak of 112 ± 20 ng/ml at 6.5 ± 2.0 h) whereas the concentration of the transmetabolite was either low or undetectable in plasma. These findings indicate the occurrence of stereospecific pre-systemic metabolism of perhexiline which reduces the bioavailability of the parent drug. The plasma elimination half-life of perhexiline was 12.4 ± 6.1 h (range 7-23 h) while that for cis-monohydroxyperhexiline was 19.9 ± 7.7 h (range 10-29 h). 3. Not more than 0.3% of unchanged perhexiline was excreted in the urine over five days in eight subjects. Between 3 and 23% of the orally administered drug was excreted as the cis- or trans-monohydroxy metabolites, the ratio of trans to cis metabolites being 0.52 ± 0.20.
Haptoglobin 2-2 phenotype is a risk factor for type 2 diabetes in Ghana
(Journal of Atherosclerosis and Thrombosis, 2006-04) Quaye, I.K.; Ababio, G.; Amoah, A.G.
We have investigated the role of haptoglobin gene polymorphisms in 129 type 2 diabetic patients and 87 non-diabetic subjects, classified by the ADA criteria, in Ghana. The diabetic subjects were recruited consecutively from the National Diabetic Management and Research Center of the University of Ghana Medical School, Korle-Bu, Accra, Ghana and were categorized by their haptoglobin phenotypes. The haptoglobin 2 allele was determined to be a risk factor for type 2 diabetes in Ghana (OR- 6.1, 95% CI - 1.8-21.2; P =.0.001) while the Hp1 allele appeared protective (OR = 0.56, 95% CI = 0.31-1.0; P =.06). The deleterious role of the Hp2 allele was further evidenced by the reduced risk associated with Hp2-1M mutant heterozygotes, who produce less Hp2 protein than the normal Hp2-1 heterozygote. (OR = 0.52, 95% CI = 0.27-1.0; P = 0.06). The subjects with the homozygous Hp2 allele were also hypertensive and overweight. There was no difference (p> 0.05) in the levels of triglycerides, total cholesterol, LDL and HDL between diabetic subjects with different haptoglobin phenotypes. We conclude that hypertensive and overweight individuals with the Hp2-2 phenotype in Ghana are at a high risk of developing type 2 diabetes and may require a more aggressive management.
High blood pressure: the foundation for epidemic cardiovascular disease in African populations
(BMC Endocrine Disorders, 2003-06) Cooper, R.S.; Amoah, A.G.; Mensah, G.A.
High blood pressure is a powerful independent risk factor for death from heart disease and stroke. It is also a common clinical condition affecting more than 600 million persons worldwide and seen in nearly all populations. Although reliable, large-scale, population-based data on high blood pressure in sub-Saharan Africa (SSA) are limited, recent studies provide important and worrisome findings in both epidemiology and clinical outcomes. Although overall hypertension prevalence is between 10%-15%, prevalence rates as high as 30%-32% have been reported in middle-income urban and some rural areas. Importantly, hypertension awareness, treatment, and control rates as low as 20%, 10%, and 1%, respectively have also been found. Stroke has been by far the most common clinical sequela. In most SSA settings, hypertension control assumes a relatively low priority and little experience exists in implementing sustainable and successful programs for drug treatment. Rapid urbanization and transition from agrarian life to the wage-earning economy of city life continue to fuel increases in average blood pressure levels and prevalence of hypertension. Although the true burden of high blood pressure in sub-Saharan Africa remains largely unmeasured, compelling preliminary evidence suggests that it is the foundation for epidemic cardiovascular disease in Africa and already contributes substantively to death and disability from stroke, heart failure, and kidney failure in this region. Success in limiting this epidemic in SSA will depend heavily on the implementation of sustainable and aggressive population-based programs for high blood pressure awareness, prevention, treatment, and control. It will be critical to obtain investments in improved surveillance and program-relevant research to provide the evidence base for policy development and effective hypertension prevention and control.
Hypertension in Ghana: a cross-sectional community prevalence study in greater Accra
(Ethnicity & Disease, 2003-06) Amoah, A.G.
Objectives: To determine the prevalence of hypertension, and the extent to which it is treated and controlled, among adult Ghanaians. Design: 6300 adults, aged 25 years and older, were selected by random cluster sampling, using electoral enumeration areas and listings of adults. Setting: Three communities in the greater Accra region of Ghana. Subjects and Methods: A total of 4733 subjects (male to female ratio=1:1.5) participated, representing a response rate of 75%. The analysis used the mean of 2 blood pressure readings, taken with a mercury sphygmomanometer after a 10-minute rest. Hypertension was defined as having blood pressure ≥140/90 mm Hg, or currently undergoing anti-hypertensive treatment. Results: The mean ages for males and females were 44.9 ± 14.7 years, and 44.0 ± 14.6 years, respectively. The crude prevalence of hypertension was 28.3%. The age-standardized prevalence, to the new standard world population, was 28.4%. Mean systolic and diastolic blood pressures increased with age. Of 1337 subjects with hypertension, 34% were aware of their condition, 18% were treated, and 4% were controlled (blood pressure <140/90 mm Hg). Conclusion: Hypertension is a major public health problem, and is associated with relatively low levels of awareness, drug treatment, and blood pressure control. Population-based prevention strategies, such as reduction in salt intake and integration of hypertension care into primary care, may prove beneficial; however, the determinants of hypertension remain to be ascertained.
Insulin resistance, beta cell function and cardiovascular risk factors in Ghanaians with varying degrees of glucose tolerance
(Ethnicity & Disease, 2002-09) Amoah, A.G.; Schuster, D.P.; Gaillard, T.; Osei, K.
Objective: Type 2 diabetes is characterized by beta cell dysfunction and insulin resistance (IR). The disease is associated with high rates of cardiovascular mortality and morbidity. Recently, the American Diabetes Association Expert Committee recommended the measurement of fasting glucose as a tool for screening and diagnosing diabetes, in order to identify patients with a mild form of the disease as well as to enhance the detection of undiagnosed type 2 diabetes. The significance of these criteria with respect to cardiovascular risk factors in native Ghanaians is unknown. The objectives of the present study were to examine the cardiovascular risk factors in a sample of native Ghanaians with varying degrees of glucose intolerance as defined by fasting glucose levels as specified by the ADA criteria. Research and Methods: The population consisted of 200 indigenous Ghanaian subjects, age range 25-74 years, residing in the Accra metropolitan areas. Subjects were categorized using the fasting plasma glucose (FPG) alone as normal fasting glucose (NFG, FPG<110mg/dL), impaired fasting glucose (IFG, 110126mg/dL). Anthropometric parameters (blood pressure, waist circumference and waist-hip circumference ratios) were measured in each subject. Levels of serum glucose, c-peptides and insulin were measured at baseline and after 2 hours of oral glucose challenge. Insulin resistance (HOMA-IR) and beta cell function (HOMA-%B) were assessed by homeostasis model assessment (HOMA). Levels of fasting serum cholesterol, high-density lipoprotein cholesterol (HDL-C), cholesterol, and triglycerides were measured in each subject. Results: There were 181 subjects in the NFG category, 11 in the IFG category, and 8 newly diagnosed type 2 diabetic subjects. The mean age, BMI, waist circumference (WC), and WHR did not differ between the 3 groups. The mean fasting glucose and the corresponding 2-hour glucose levels rose with the worsening of glucose tolerance. Similarly, the means for serum fasting, post-challenge serum insulin, and c-peptide levels were significantly greater in the IFG and DM groups. Fasting serum cholesterol and high density lipoproteins did not differ statistically between the 3 groups, However, the means for serum triglycerides were greater in the IFG and DM groups when compared to the NFG group. The insulin resistance (IR) as assessed by HOMA was 2X and 4X greater in the Conclusions: We have characterized the metabolic and anthropometric risk factors for CVD in native Ghanaians with varying degrees of glucose tolerance, as defined by the ADA criteria. We found that both IFG and DM were associated with beta cell dysfunction, insulin resistance, and elevated serum triglycerides. However, the well established cardiovascular risk factors, such as body mass index, body fat distribution, and blood pressure did not track with the increasing glucose intolerance in the native Ghanaians. We conclude that the Ghanaian patients with IFG and type 2 diabetes were non-obese and exhibited severe beta cell dysfunction, insulin resistance, and elevated triglycerides, but none of the other conventional risk factors, at the time of diagnosis. Future research should focus on the sequential changes in risk factors during development of cardiovascular diseases in native Ghanaians with varying degrees of glucose tolerance.
Insulin sensitivity and cardiovascular risk factors in hypertensive and normotensive native ghanaians
(Diabetologia, 2003-07-01) Amoah, A.G.; Schuster, D.P.; Gaillard, T.; Osei, K.
Aims/Hypothesis. The objective of this study was to examine the relationships among insulin and insulin sensitivity and risk factors for cardiovascular diseases in native Ghanaians with and without hypertension. Methods. We measured the anthropometric parameters, systolic and diastolic blood pressure, fasting serum triglycerides, cholesterol and high-density lipoprotein cholesterol and fasting and stimulated glucose, insulin and C-peptide of 200 Ghanaian subjects, who were between 25 to 74 years of age, and residing in the Accra Metropolitan area. Serum glucose, C-peptide and insulin concentrations were measured at baseline (fasting) and also 2 h after 75 gm oral glucose drink. Homeostasis model assessment was used to measure insulin resistance. Hypertension was defined as a blood pressure higher than 140/90 mmHg. Results. There were 53 subjects with hypertension (HBP) and 147 subjects with normal blood pressure (NBP). The mean BMI, waist circumference and waist-to-hip circumference ratio for HBP and NBP subjects were 27.4±0.8, 24.8±0.4 kg/m 2; 89.8±11.7, 81.1±0.9 cm; and 0.87±0.08, 0.82±0.08 respectively, (p<0.05). The fasting and 2-h plasma glucose concentrations in HBP and NBP subjects were 5.5±0.2, 7.2±0.3 mmol/1 and 5.2±01, 6.8±0.2 mmol/l respectively (p>0.05). The corresponding fasting and 2-h insulin concentrations were 10.0±0.7, 8.0±0.4 uU/ml and 47.3±3.7, 37.3±2.5 uU/ml respectively (p<0.05). The insulin resistance index (HOMA-IR) in the HBP and the NBP groups were 2.49±0.2 and 1.95±0.13 (p<0.05). The two groups had similar fasting and stimulated C-peptide, lipids and HDL concentrations. Correlations were found between blood pressure and the concentrations of lipids, HDL, fasting and stimulated insulin and C-peptide, and between fasting insulin and HOMA-IR with lipids and HDL concentrations. On multiple regression analysis, fasting insulin and HOMA-IR did not influence blood pressure variations significantly. Conclusions/interpretation. We found clustering of hyperinsulinaemia, insulin resistance and truncal obesity in hypertensive Ghanaian subjects but dissociation between insulin resistance, hypertension and atherogenic lipid and lipoprotein profile.
Minimal model analyses of beta cell secretion, insulin sensitivity and glucose effectiveness in glucose tolerant, non-diabetic first-degree relatives of Ghanaian patients with type 2 diabetes and healthy control subjects
(Ethnicity & Disease, 2001-03) Amoah, A.G.; Owusu, S.K.; Ayittey, O.M.; Schuster, D.P.; Osei, K.
Objective: We have examined the importance of positive family history of type 2 diabetes on serum glucose, insulin sensitivity, and beta cell secretion in native West Africans (Ghanaians) who reside in their native country. Research and Methods: We evaluated the beta cell secretion, insulin secretion, insulin sensitivity (Si), and glucose effectiveness (Sg) in 42 healthy non-diabetic first-degree relatives of Ghanaian patients with type 2 diabetes (26 females and 16 males) and in 22 healthy control subjects without a family history of type 2 diabetes (12 females and 10 males) living in Accra, Ghana, West Africa. A standard oral glucose tolerance test (OGTT) and a frequently sampled intravenous glucose tolerance (FSIGT) test were performed in each subject. Si and Sg were measured using Bergman's minimal model method. Results: During oral glucose challenge, fasting and postprandial serum glucose levels were not significantly different between the relatives and healthy controls. Mean serum insulin and c-peptide responses after oral glucose tolerance test at t = 60, 90 and 120 minutes (P<.05) were significantly greater in the relatives than in the healthy controls. During the FSIGT, the mean serum glucose responses did not differ. Mean total and acute first and second phases of serum insulin and c-peptide responses were greater in the relatives than in the healthy controls. We found that the Si tended to be lower in the relatives than in the controls, but the mean difference did not vary significantly between the two groups. In addition, the glucose effectiveness at basal insulin level (Sg) was not significantly different in the relatives and healthy controls. Conclusions: The present study demonstrates that hyperinsulinemia and a tendency to lower insulin sensitivity (insulin resistance), but not altered glucose effectiveness, are found in healthy non-diabetic, first-degree relatives of Ghanaian patients with type 2 diabetes as compared to healthy subjects living in their native country. We conclude that genetic factors could play a significant role in the development of type 2 diabetes in indigenous Ghanaians residing in their native country.
A national diabetes care and education programme: the Ghana model
(Diabetes Research and Clinical Practice, 2000-08) Amoah, A.G.; Owusu, S.K.; Acheampong, J.W.; Agyenim-Boateng, K.; Asare, H.R.; Owusu, A.A.; Mensah-Poku, M.F.; Adamu, F.C.; Amegashie, R.A.; Saunders, J.T.; Fang, W.L.; Pastors, J.G.; Sanborn, C.; Barrett, E.J.; Woode, M.K.
An account is given of how a national diabetes care and education programme was developed in Ghana, a developing country, through international collaboration of medical schools, industry and government health care institutions. The approach is by way of trained diabetes teams consisting of physicians, dietitians and nurse educators at two tertiary institutional levels (teaching hospitals) who in turn trained teams consisting of physicians, dietitians or diettherapy nurses, nurse educators and pharmacists at regional and district/sub-regional levels to offer care and education to patients and the community. In three years all regional and about 63% of sub- regional/district health facilities had trained diabetes health care teams, run diabetes services and had diabetes registers at these institutions. Additionally a set of guidelines for diabetes care and education was produced. All programme objectives with the exception of one (deployment of diabetes kits) were met. Distances to be travelled by persons with diabetes to receive diabetes care had been reduced considerably. The success of the project has given an impetus to the collaborators to extend the programme to the primary health care level. The continuing prohibitive prices of diabetes medications and supplies however, could be addressed by removing taxes on such supplies. The Ghana diabetes care model, a 'top-down' approach, initially involving two diabetes centres is recommended to other developing countries, which intend to incorporate diabetes care and education into their health care system.
Obesity in adult residents of Accra, Ghana
(Ethnicity & Disease, 2003-06) Amoah, A.G.
Objectives: To determine the prevalence of obesity in Ghanaian adults. Design: 6300 adults, aged 25 years and older, were selected by random cluster sampling using electoral enumeration areas and listings of adults. Setting: Two urban and one rural community in the Greater Accra region of Ghana. Subjects and Methods: 4733 (males=1860, females=2873) adult Ghanaians participated. Height and weight were determined for subjects wearing light clothing and without shoes. Results: The mean age and BMI were 44.3 years and 24.4 kg/m2, respectively. Women, though younger, had higher BMI values compared to males (25.6 vs 22.6 kg/m2, respectively; P<.001). The overall crude prevalence of overweight (25.0-29.9 kg/m2 ) and obesity (≥30 kg/m2) were 23.4% and 14.1% for females and males, respectively. The rates of overweight (27.1% vs 17.5%) and obesity (20.2% vs 4.6%) were both higher in women than men. The age-standardized prevalence of obesity in Ghanaians was 13.6%. Obesity increased with age, peaking in the 55-64-year age group. The first to fourth BMI quartiles were: ≤520.6, 20.7-23.3, 23.4-27.2, and ≥27.3 kg/m2, respectively. At all ages, more females (32.9%) than males (12%) were placed within the 4th BMI quartile. Residents from the high-class residential area had higher BMI, compared to subjects from the lower class suburb. Also, urban residents had higher BMI compared to rural subjects. Conclusion: Overweight and obesity are common in Ghanaians, particularly among females, the elderly, and urban dwellers. Further work is needed to ascertain the determinants of overweight and obesity in Ghanaians.
Pathogenesis of type 1 and type 2 diabetes mellitus in sub-Saharan Africa: implications for transitional populations
(Journal of Cardiovascular Risk, 2003-04) Osei, K.; Schuster, D.P.; Amoah, A.G.; Owusu, S.K.
The increasing prevalence and incidence of diabetes and its long-term complications in sub-Saharan Africa (SSA) could have devastating human and economic toll if the trends remain unabated in the future. Approximately 90% or majority of patients with diabetes belongs to the adult onset, type 2 diabetes category while 10% have type 1 diabetes in SSA. However, because of the paucity of metabolic and clinical data, a clear understanding of the natural history of both diseases and the classification of diabetes subtypes has been hampered. Nevertheless, we have attempted to provide a concise review of the pathophysiology of both type I and type 2 diabetes as well as phenotypic and clinical variations in patients residing in SSA. The limited metabolic data, (albeit increasing), from high-risk and diabetic individuals in the SSA, have contributed significantly to the understanding of the pathogenetic mechanisms of diabetes and the variations in the presentation of the disease. Sub-Saharan African patients with type I diabetes have essentially absolute insulin deficiency. In addition, patients with type 2 diabetes in SSA region also manifest severe insulin deficiency with varying degrees of insulin resistance. Although the exact genetic markers of both diseases are unknown, we believe studies in patients of SSA origin who reside in diverse geographic environments (African diaspora) could potentially contribute to our understanding of the genetic and environmental mediators of both diseases. However, many intrinsic, individual and societal obstacles such as poor education and illiteracy, low socio-economic status and lack of access to health care make uncertain the translation of diabetes research in SSA. In this regard, effective management and/or prevention of diabetes in SSA individuals should adopt multidisciplinary approaches. Finally, innovative health care delivery and educational models will be needed to manage diabetes and its long-term complications in SSA.
Pathogenic mechanism of type 2 diabetes in Ghanaians--the importance of beta cell secretion, insulin sensitivity and glucose effectiveness
(South African Medical Journal, 2002) Amoah, A.G.; Owusu, S.K.; Schuster, D.P.; Osei, K.
Objective. To assess insulin sensitivity and beta cell secretion in indigenous Ghanaian subjects with a spectrum of glucose intolerance. Research and methods. We evaluated beta cell secretion, insulin sensitivity (Si) and glucose effectiveness (Sg) in three groups: group 1, 15 healthy control subjects without family history of type 2 diabetes; group 2, 11 healthy non-diabetic first-degree relatives of Ghanaian patients with type 2 diabetes; and group 3, 10 patients with type 2 diabetes living in Accra, Ghana, West Africa. A standard oral glucose tolerance test (OGTT) and frequently sampled intravenous glucose tolerance (FSIGT) test were performed for each subject. Si and Sg were measured using Bergman's minimal model method. Results. The mean body mass index (BMI) and lean body mass were not different among the three groups. However, the waist-to-hip circumference ratio, total body fat as well as triceps and biceps skinfolds were significantly greater in group 3 (diabetic patients) than in group 2 (relatives) and group 1 (healthy controls). Mean fasting and postprandial serum glucose levels were not significantly different between the relatives and healthy controls during oral glucose challenge. The mean fasting and postprandial serum glucose levels were significantly higher in the group 3 diabetic patients than in the non-diabetic groups. Mean fasting serum insulin and C-peptide levels tended to be higher in group 3 than in groups 1 and 2. However, mean serum insulin and C-peptide responses after oral glucose load were significantly greater in group 2 than in the group 1 healthy controls. The insulin responses in the two non-diabetic groups after oral glucose challenge were significantly greater than in the diabetic patients. During the FSIGT, the mean serum glucose responses were similar in the two non-diabetic groups (groups 1 and 2). The serum glucose responses were significantly greater in group 3 than in the non-diabetic groups. Mean total and acute first and second phases of insulin and C-peptide responses were greater in group 2 than group 1. However, acute phases of insulin secretion were severely blunted in group 3 when compared with groups 1 and 2 during FSIGT in our Ghanaians. We found that the mean Si was slightly lower in group 2 (1.72 ± 0.32) than in the healthy controls in group 1 (1.9 ± 0.55, P = NS). Mean Si was remarkably lower in the diabetic patients in group 3 (1.30 ± 0.35 x 10-4/min (μU/ml)) when compared with the relatives and healthy controls, but the differences were not statistically significant. Mean glucose effectiveness at basal insulin level (Sg) was not significantly different among the relatives in group 2 (2.38 ± 0.50), the healthy controls in group 1 (2.66 ± 0.38) and the diabetic patients in group 3 (2.27 ± 0.49 x 10-2/min). Conclusions. We conclude that (i) the pathogenetic mechanisms of type 2 diabetes in indigenous Ghanaians are characterised by severe beta cell dysfunction and moderate reduction in Si. Although the healthy relatives manifest insulin resistance with compensatory hyperinsulinaemia, our study suggests that the conversion of such subjects to type 2 diabetes is determined by deterioration in beta cell function and perhaps Si but not tissue Sg in Ghanaians. Prospective studies are needed to examine the sequential changes that lead to the development of type 2 diabetes in indigenous Ghanaians.