Elsevier

Diabetes & Metabolism

Volume 38, Issue 4, October 2012, Pages 324-331
Diabetes & Metabolism

Original article
Age and living in an urban environment are major determinants of diabetes among South Kivu Congolese adultsL’âge et le milieu urbain sont des déterminants majeurs du diabète sucré chez l’adulte congolais du Sud-Kivu

https://doi.org/10.1016/j.diabet.2012.02.008Get rights and content

Abstract

Objectives

This study aimed to determine the risk factors for diabetes mellitus (DM) in the eastern part of the Democratic Republic of Congo.

Methodology

Multilevel sampling identified 200 households (444 adults aged  20 years) from 20 neighbourhoods in the city of Bukavu, and 90 households (255 adults aged  20 years) from 10 villages in the Kaziba (South Kivu) chiefdom (the South Kivu VITARAA study). DM was defined as a personal history of the disorder or a casual glycaemia greater or equal to 200 mg/dL. Standardization according to age and sample readjustment based on the urban–rural distribution of the population was applied accordance with the typical Congolese population. The probability of DM was assessed by multiple logistic regressions.

Results

Total prevalence of DM was 3.5%. DM was significantly more prevalent in urban areas (age-standardized prevalence: 4.0%) than in rural areas (1.7%). City-dwelling DM patients were characterized by higher rates of indices of abdominal obesity (P < 0.05) whereas, in rural areas, no patients were obese. In the study group as a whole, only 25.0% of diabetic patients were obese. On multivariate analyses, only age [adjusted OR (95% CI): 4.79 (1.60–14.25); P = 0.004] was independently associated with the prevalence of DM, while the effect of obesity was not significant [2.64 (0.99–7.02); P = 0.051].

Conclusion

Age and living in an urban environment appeared to be major determinants of DM in South Kivu. Also, obesity prevalence was relatively low in these diabetic patients, confirming the peculiar, relatively lean, phenotype of type 2 DM in indigenous sub-Saharan Africans.

Résumé

Objectifs

Déterminer les facteurs de risque du diabète sucré dans la partie Est de la République Démocratique (RD) du Congo.

Méthodologie

Un sondage à plusieurs degrés a permis l’identification de 200 ménages (444 adultes  20 ans), sélectionnés parmi 20 quartiers de la ville de Bukavu et 90 (255 adultes  20 ans) parmi dix villages de la chefferie de Kaziba au Sud-Kivu (étude VITARAA au Sud-Kivu). Le diabète sucré (DS) a été défini par une histoire personnelle de cette affection ou une glycémie supérieure ou égale à 200 mg/dL. Une standardisation selon l’âge et un redressement de l’échantillon sur la répartition urbano-rurale de la population ont été réalisés à partir d’une population congolaise type. La probabilité du DS a été modélisée par régression logistique multiple.

Résultats

La prévalence totale du DS était de 3,5 %. Le DS était significativement plus fréquent en milieu urbain [Prévalence ajusté à l’âge = 4,0 %] qu’en zones rurales [1,7 %]. Les patients diabétiques en milieu urbain ont été caractérisés par des taux plus élevés d’indices d’obésité abdominale [P < 0,05], tandis que dans les zones rurales, aucun patient n’était obèse. Dans l’ensemble du groupe, seuls 25,0 % des diabétiques étaient obèses. Dans l’analyse multivariée, seul l’âge [OR ajusté (IC à 95 %) : 4,79 (1,60 à 14,25), P = 0,004] était indépendamment associé au risque du DS. L’effet de l’obésité était à la limite de signification [2,64 (0,99 à 7,02), P = 0,051].

Conclusions

L’âge et l’environnement urbain semblent être les principaux déterminants du diabète sucré dans le Sud-Kivu. Toutefois, la prévalence d’obésité était relativement faible chez les diabétiques, ce qui confirme le phénotype relativement mince des diabétiques de type 2 parmi les autochtones d’Afrique subsaharienne.

Introduction

Diabetes mellitus (DM) represents a worldwide public-health problem, and its prevalence is relentlessly increasing. From 1985 to 2000, the global prevalence of diabetic patients rose from 30 to 157 million, while the projections for 2030 estimate that this number will reach 366 million [1]. The majority of cases represent type 2 diabetes mellitus (T2DM). Each year, DM is responsible for more than one million deaths worldwide [2]. The major complications associated with chronic hyperglycaemia and T2DM co-morbidities (such as hypertension and dyslipidaemia) include micro- and macroangiopathy, with diabetic eye disease, diabetic nephropathy, coronary heart disease, stroke and lower-limb non-traumatic amputation responsible for the bulk of diabetes-related morbidity [3].

With an increased rate estimated at 170% compared with a 41% prevalence of DM in the developed countries, developing countries such as the Democratic Republic of Congo (DRC) are poised to face a surge in T2DM prevalence following the increasingly reported anticipated changes in lifestyle in these populations, especially in urban situations [1], [4], [5].

As for the DRC, the World Health Organization (WHO) estimates a prevalence of DM of less than 3% [1], citing studies undertaken in Tanzania [6], a country with some similarities to the DRC. However, investigations carried out of adult populations in the Kinshasa studies, which were mostly urban-based, put the prevalence of T2DM between 7% and 16% [7], [8], and the African WHO Regional Office now classifies the DRC among those countries in which the DM prevalence is between 7% and 10% [4].

Generalizing such results to the whole of the DRC, however, could prove hazardous, given the wide socioeconomic and lifestyle disparities in a population that is still overwhelmingly (57%) rural [9].

That is why the present study has focused on evaluating, within another DRC region, the urban vs rural differences and their relationship to risk factors of DM.

Section snippets

Study participants and sampling

The Visite de tension artérielle et du risque associé en Afrique (VITARAA; evaluation of arterial blood pressure and its associated risk in Africa) was conducted in Cameroon and in the DRC in 2008. The present report presents the results obtained in the region of South Kivu in the eastern part of the DRC [10].

In this region, multilevel sampling yielded the identification of 290 potential households, of which 200 were selected from 20 neighbourhoods (322 streets) in the city of Bukavu (with an

Results

The study participants’ general characteristics are shown in Table 1. Of the 669 subjects in the investigation, 424 lived in urban areas vs 245 in rural areas. Mean age, BMI, AC, systolic blood pressure (SBP), diastolic blood pressure (DBP) and glycaemia were 42.5 ± 18.1 years, 23.7 ± 4.4 kg/m2, 82.3 ± 11.8 cm, 130.5 ± 21.1 mmHg, 82.9 ± 13.0 mmHg and 103.5 ± 46.8 mg/dL, respectively.

Discussion

The present investigation's main findings were that DM is prevalent in the eastern part of the DRC (3.5%), and significantly more prevalent in urban (age-standardized prevalence: 4.0%) than in rural (1.7%) populations. Urban-dwelling patients were characterized by higher rates of indices of abdominal obesity (P < 0.05) whereas, in rural areas, there was no statistically significant difference in indices of abdominal obesity among those with and without DM (P > 0.05). Age was, however, a major

Disclosure of interest

The authors declare that they have no conflicts of interest concerning this article.

Acknowledgements

The authors thank A.F. Akamba, M.D., R. Baderha Ngabo, M.D., B.M. Balola, M.D., Z.C. Baseme, M.D., K.A. Mukendi, M.D., C.F. Murhula, M.D., B.M. Murhesa, M.D., M.L. Mutimbwa, M.D., S.J. Neze, M.D., M.R. Ntumwa, M.M. Shakangana, M.D., M.H. Watukalusu, M.D. and K.G. Yenga, M.D. for their enthusiastic participation in data collection, and the NGO Leuven Development Cooperation in Central Africa for funding the surveys in South Kivu.

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