Clinical and biological characteristics of diabetic patients under age 40 in Cameroon: relation to autoantibody status and comparison with Belgian patients.

AIMS: We investigated the prevalence of diabetes autoantibodies (Abs) in Cameroonian patients and controls, assessed their contribution in disease classification and compared results with data from Belgium. METHODS: Abs against GAD (GADA), IA-2 (IA-2A) and zinc transporter 8 (ZnT8A) were assessed in 302 recently diagnosed Cameroonian patients with diabetes and 184 control subjects without diabetes aged below 40 years. RESULTS: Only 27 (9%) Cameroonian patients were younger than 15 years. Overall, 29% of patients presented at least one diabetes-associated antibody vs 9% in healthy controls (24% vs 7% for GADA (p<0.001), 10% vs 3% for IA-2A (p<0.006), 4% vs 2% for ZnT8A). Ab(+) patients had lower C-peptide levels (p<0.001), were more often insulin-treated (p<0.002) and were as frequently diagnosed with type 1 diabetes as Ab(-) patients. Only 43% of Ab(+) patients aged 15-39 years were clinically classified as having type 1 diabetes in Cameroon vs 96% in Belgium (p<0.001). Not one Ab(+) Cameroonian patient carried HLA-DQ2/DQ8 genotype vs 23% of Belgian Ab(+) patients (p<0.001). Younger age at diagnosis and antibody positivity were independent predictors of insulin therapy. Ab(+) Cameroonian patients were older (p<0.001), had higher BMI (p<0.001) and lower Ab titers than Belgian Ab(+) patients. In ketonuric patients, prevalence of autoantibodies was similar as in non-ketonuric patients. CONCLUSIONS: In Cameroonian patients with diabetes aged under 40 years, antibody-positivity is not clearly related to disease phenotype, but may help predict the need for insulin treatment.

Diabetes in sub-Saharan Africa.

In Sub-Saharan Africa, prevalence and burden of type 2 diabetes are rising quickly. Rapid uncontrolled urbanisation and major changes in lifestyle could be driving this epidemic. The increase presents a substantial public health and socioeconomic burden in the face of scarce resources. Some types of diabetes arise at younger ages in African than in European populations. Ketosis-prone atypical diabetes is mostly recorded in people of African origin, but its epidemiology is not understood fully because data for pathogenesis and subtypes of diabetes in sub-Saharan African communities are scarce. The rate of undiagnosed diabetes is high in most countries of sub-Saharan Africa, and individuals who are unaware they have the disorder are at very high risk of chronic complications. Therefore, the rate of diabetes-related morbidity and mortality in this region could grow substantially. A multisectoral approach to diabetes control and care is vital for expansion of socioculturally appropriate diabetes programmes in sub-Saharan African countries.

Ten-year changes in central obesity and BMI in rural and urban Cameroon.

OBJECTIVE: To compare the 10-year changes in the distribution of adiposity in rural and urban Cameroonian populations. METHODS AND PROCEDURES: Two cross-sectional surveys of populations in the same rural and urban areas of Cameroon, aged>or=24 years, were carried out in 1994 (1,762 subjects) and 2003 (1,398 subjects) using similar methodology. All eligible subjects answered a structured questionnaire on their educational level, alcohol consumption, and tobacco smoking and weight, height, and waist circumference (WC) were measured. RESULTS: Between 1994 and 2003, the age-standardized prevalence of BMI>or=25 kg/m2 increased significantly only in the rural area (+54% for women and +82% for men), while the age-standardized prevalence of central obesity (WC>or=80 cm (women), >or=94 cm (men)) increased significantly only in the urban population (+32% for women and +190% for men). These differences persisted after adjustments for age group, alcohol consumption, tobacco smoking, and level of education, and within almost all the strata of the studied risk factors. DISCUSSION: Changes in adiposity over time in Cameroon were characterized by an increase of BMI in the rural area and of WC in the urban area.

Standardized comparison of glucose intolerance in West African-origin populations of rural and urban Cameroon, Jamaica, and Caribbean migrants to Britain

OBJECTIVE: To compare the prevalence of glucose intolerance in genetically similar African-origin populations within Cameroon and from Jamaica and Britain. RESEARCH DESIGN AND METHODS: Subjects studied were from rural and urban Cameroon or from Jamaica, or were Caribbean migrants, mainly Jamaican, living in Manchester, England. Sampling bases included a local census of adults aged 25-74 years in Cameroon, districts statistically representative in Jamaica, and population registers in Manchester. African-Caribbean ethnicity required three grandparents of this ethnicity. Diabetes was defined by the World Health Organization (WHO) 1985 criteria using a 75-g oral glucose tolerance test (2-h > or = 11.1 mmol/l or hypoglycemic treatment) and by the new American Diabetes Association criteria (fasting glucose > or = 7.0 mmol/l or hypoglycemic treatment). RESULTS: For men, mean BMIs were greatest in urban Cameroon and Manchester (25-27 kg/m2); in women, these were similarly high in urban Cameroon and Jamaica and highest in Manchester (27-28 kg/m2). The age-standardized diabetes prevalence using WHO criteria was 0.8 percent in rural Cameroon, 2.0 percent in urban Cameroon, 8.5 percent in Jamaica, and 14.6 percent in Manchester, with no difference between sexes (men: 1.1 percent, 1.0 percent, 6.5 percent, 15.3 percent, women: 0.5 percent, 2.8 percent, 10.6 percent, 14.0 percent), all tests for trend P < 0.001. Impaired glucose tolerance was more frequent in Jamaica. CONCLUSIONS: The transition in glucose intolerance from Cameroon to Jamaica and Britain suggests that environment determines diabetes prevalence in these populations of similar genetic origin.(Au)

Sick genes, sick individuals, or sick populations with chronic disease? An international example from a standardized study of glucose tolerance and high blood pressure

Intensive searches for genes predisposing to or "causing" chronic disease are based on familial patterns indicating gene based inheritance. Rose's paradigm, less popular with clinical scientist thinking in individuals, is that populations give rise to their extreme values who become patients. For diabetes (NIDDM), population-based twin registers (e.g. Denmark) show little mono-to-di-zygotic difference, a suggesting major hospital ascertainment bias in ascribing a genetic basis to NIDDM. Here we examined geographically dispersed populations of West African origin, or similar genetic background within Cameroon, then between Jamaica and African-Caribbean (AfC) migrants to Britain (70 percent from Jamaica). Carefully representive samples were drawn from local population registers in rural and urban Cameroon, Jamaica and Manchester, UK. Results, on similar genetic backgrounds in the Cameroon, and between Jamaica and Manchester, suggest factors affecting energy balance (intake versus expenditure) rather than gene differences determine diabetes and, probably, hypertension rates in these and, probably, most populations.(AU)

Standardised comparison of glucose tolerance and diabetes prevalence in four African/African-Caribbean populations in Britain, Jamaica and Cameroon

To study factors promoting the emergence of diabetes in African-Caribbean (AfC) as the second largest ethnic minority in Britain and how these compare with genetically similar populations in Jamaica (origin of 80 percent AfC) and Cameroon, using the same protocol we carried out 75g glucose tolerance tests in representative community samples aged 25-74 years, by WHO criteria. As results were similar by gender, sexes are combined here. [See table] Diabetes prevalence (age-standardised) increased from Africa to the Caribbean to Europe and was highest in Manchester men. Body mass index showed a striking increase from rural to younger urban Cameroonians. Increasing NIDDM prevalence is paralleled across site by changes in nutritional and lifestyle factors, also measured using standardised methods. Even in Cameroon, prevalence approaches rates in whites in Europe.(AU)

Development of food frequency questionnaires in three population samples of African origin from Cameroon, Jamaica and Caribbean migrants to the UK

OBJECTIVES: To develop the methods for assessment of food and nutrient intake using standardized food frequency questionnaires (FFQ) in three African origin populations from Cameroon, Jamaica and Caribbean migrants to the United Kingdom. DESIGN: Cross-sectional assessment of diet from a representative sample in each site, using either a 2-day food dairy or a 24-h recall method to determine food for inclusion on the food frequency questionnaire. SETTING: A rural and urban site in Cameroon, Evodoula and Cite Verte in Yaounde, respectively; a district in Kingston, Jamaica; Afro-Caribbeans living in central Manchester, UK. SUBJECTS: Aged 25-79 years, 61 from the Cameroonian urban site, 62 from village site; 102 subjects from Jamaica (additional analysis on a subsample of 20): 29 subjects from Manchester, UK. MAIN OUTCOME MEASURES: Food contributing to nutrients in each site to allow the development of a FFQ. RESULTS: A high response rate was obtained in each site. Comparison of macronutrient intakes between the sites showed that carbohydrate was the most important contributor to energy intake in Jamaica (55 percent) and the least in the rural Cameroon. In rural Cameroon, fat (mainly palm oil) was the most important contributor to energy intake (44 percent). Manchester had the highest contribution of protein energy (17 percent). Food contributing to toal energy, protein, fat and carbohydrate were determined. In rural Cameroon, the top 10 food items contributed 66 percent of the total energy intake compared to 37 percent for the top 10 foods in Manchester. Food contributing to energy were similar in Jamaica and Manchester. Cassava contributed 40 percent of the carbohydrate intake in rural Cameroon and only 6 percent in urban Cameroon. One FFQ has been developed for use in both sites in Cameroon containing 76 food items. The FFQ for Jamaica contains 69 foods and for Manchester 108 food items. CONCLUSION: Considerable variations exist within sites (Cameroon) and between sites in foods which are important contributors to nutrient intakes. With careful exploration of eating habits it has been possible to develop standardized, but locally appropriate FFQs for use in African populations in different countries.(AU)

Development of food frequency questionaires in three population samples of African origin from Cameroon, Jamaica and Caribbean

OBJECTIVES: To develop the methods of assessment of food and nutrient intake using standardized food frequency questionnaires (FFQ) in three African origin population from Cameroon, Jamaica and Caribbean migrants to the United Kingdom. DESIGN: Cross-sectional assessment of diet from a representative sample in each site, using either a 2-day food diary or a 24-h recall method to determine foods for inclusion on the food frequency questionnaire. SETTING: A rural and urban site in Cameroon, Evodoula and Cite Verte in Yaounde, respectively; a district in Kingston Jamaica; African-Caribbeans living in central Manchester, UK. SUBJECTS: Aged 25-79 years, 61 from the Cameroonian urban site, 62 from the village site, 102 subjects from Jamaica (additional analysis on a subsample of 20): 29 subjects from Manchester, UK. MAIN OUTCOME MEASURES: Foods contributing to nutrients in each site to allow the development of a FFQ. RESULTS: A high response rate was obtained in each site. Comparison of macronutrient intakes between the sites showed that carbohydrates was important contributor to energy intake in Jamaica (55 percent) and the least in rural Cameroon. In rural Cameroon, fat (mainly palm oil) was the most important contributor to energy intake (44 percent). Manchester had the highest contribution of protein to energy (17 percent). Food contributing to total energy, protein, fat and carbohydrate were determined. In rural Cameroon, the top of 10 food items contributed 66 percent of the total energy intake compared to 37 percent for the top 10 foods in Manchester. Foods contributing to energy were similar in Jamaica and Manchester. Cassava contributed 44 percent of the carbohydrate intake in rural Cameroon and only 6 percent in urban Cameroon. One FFQ had been developed for use in both sites in Cameroon containing 76 food items. The FFQ for Jamaica contains 69 foods and for Manchester 108 food items. CONCLUSION: Considerable variations exist within sites (Cameroon) and between sites in foods which are important contributors to nutrients intakes. With careful exploration of eating habits it has been possible to develop standardized, but locally appropriate FFQs for the use in African population in different countres.(AU)

Assessing dietary intakes in relation to diabetes mellitus and hypertension in Afro-origin population samples in Cameroon, Jamaica and Caribbean migrants to Europe - abstract

This international study examines nutritional influences on emerging diabetes mellitus and hypertension in Afro-origin populations, in random samples aged 25 - 79 years. The aim is to assess habitual food and nutrient intake from food frequency questionnaires (FFQ) built up, piloted, used and recalibrated with 24 hr recalls and food diaries and to relate these results of 75 g WHO glucose tolerance tests (GTT), blood pressure (BP) and anthropometric measurements. Method standardizing is essential so as to compare between as well as within sites. The paper emphasizes nutritional methods. In Jamaica, FFQs were developed from 104 Kingston residents, then applied in Spanish Town enumeration districts; in Manchester, from 40 Caribbean (84 percent Jamaican origin) and in Cameroon from 76 randomly sampled city, and 79 rural, households, with 76 - 79 percent response rates. Items contributing > 90 percent to macronutrient and total energy intake were included on FFQs, totalling 69 foods in Jamaica, 108 in Manchester and 76 m Cameroon. These were administered during and after the GTTs, taking some 40 minutes. For 350 subjects per site (response 65 - 88 percent), mean age-stratified body mass indices (BMI) ranged from 23.4 - 26.4 kg/mý in younger Cameroonian, Jamaican and Manchester men; respective female BMIs were higher at 26-28, 26-27 and 25 - 31. Manchester FFQ results for 101 subjects, generally low incomes, showed that almost all diets contain typical West Indian foods despite greater cost. Portion sizes are different for the same food compared with both the national UK and Jamaican populations (e.g. medium serving rice - 260 g vs 150 g), illustrating the importance of portion size data specific to each population. Percent energy from fat is lower and from carbohydrates much higher than in the national UK population, as are fruit and vegetable intakes and alcohol intakes in men. Jamaican values were intermediate between those in Britain and Cameroon where food habits and same-dish composition differed substantially, with a wider variety consumed in the city. Village diets from 200 FFQs consisted mainly of green leafy vegetables. These results show that standardised methods of building up instruments to assess nutritional intakes cross-culturally are feasible and can be applied in population studies of chronic disease (AU)

Nutritional influences on the emergence of diabetes mellitus and high blood pressure in Afro-origin populations in Cameroon, Jamaica, and Caribbean migrants to Europe - abstract

Our four nation study is establishing the role of nutrition in evolving diabetes mellitus (DM) and high blood pressure (BP) in these Afro-origin populations. Using highly standardized methods, we are testing whether increasing energy (particularly fat) and Na+ intakes, and decreased K+, Ca+ and antioxidant intakes, are associated with decreasing glucose tolerance (GT) and increasing BP within and between centres. Random community samples, aged 25 - 74 years, are stratified by sex up to 1,500/centre to generate sufficient index cases of impaired (I) GT and `high' BP (> 140 and/or 90 mm Hg but < 160 to 95 mm Hg) for an intervention trial and incident phase. During a 2-hr 759 glucose tolerance test (GTT), a food frequency questionnaire (FQQ), built up from food dairies and 24-hr recalls, and repeat 24-hr urines are supplying mean energy, fat, carbohydrate, fibre, protein and cation intakes. To date, 894 Jamaicans have been seen at the Spanish Town site, some 780 people (360 Afro-Caribbean) in Manchester, with 180 GT tested, 416 Cameroonians (246 urban) and a pilot study completed in Paris. Rates of IGT and DM run at approximately 8 percent and 14 percent in Jamaica, 15 percent of each in Manchester, and 4-8 percent in Cameroon through Jamaica to Manchester. Those at risk of hypertension (> 140 and/or 90 mm Hg) are similarly distributed. As baseline prevalence rates are established, the nutritionally-based intervention programme will be piloted as a randomized trial. Such efforts offer the chance for primary prevention of high BP, diabetes mellitus and their complications in these populations, before or as they face an epidemic from them (AU)