|ISSN No. 1606-7754 Vol.16 No.1 April 2008|
Higher pulse pressure, systolic arterial hypertension, duration of diabetes and family history of diabetes in Central Africans
Longo- Mbenza B1, Nkondi Mbadi A Nsungu J2, Mbungu Fuele S3
University of Kinshasa, Division of Cardiology, Pathophysiology, and Clinical Epidemiology1, General Hospital of Kinshasa2, Lomo Medical Center3, Unity of Clinical Epidemiology and Biostatistics, Congo
Objective: to assess the prevalence and the risk factors of diabetic retinopathy (DR) in urban diabetics from Kinshasa, DRC. Methods: this is a community-based cross-sectional survey and a case-control study on diabetic retinopathy in Kinshasa, the capital of DRC. The medical charts of all diabetics (n=3010) ≥ 20 years were studied to estimate the prevalence of DR during November 2004. 10% (n=301) of these were randomly selected to reveal 95 diabetics with DR and 206 diabetics without DR (control). Both groups were matched for primary care centre, sex, age, body mass index, and waist circumference, attending the primary care centres between December 2004 and December 2005, and were screened for DR using stereo color photography and ophthalmoscopy. Results: the overall prevalence rate of DR in the population was 31.6% (n=950 95% confidence interval [CI]:26.3 – 36.9). Delayed diagnosis of diabetes (≥55 years) in the study sample in women, men with high socioeconomic status, and pregnancy onset after the diagnosis of DR among women, were identified as variables for Univariate analysis and for significant risk factors of DR. Logistic regression analysis showed that longer duration of diabetes (≥4years) (LDD), systolic arterial hypertension (SAH), higher pulse pressure (≥60 mmHg, clinical pre-atherosclerosis/arterial stiffness), and family history of diabetes (FHD), were the significant and independent determinants of DR in the sample study. The multivariate risk of DR conferred by these determinants is enhanced among female diabetics (y=2.679 + 1.528 SHT + 1.080 LDD + FHD; p<0.01) and patients with type 2 diabetes (y=2.725 + 1.316 SHT + LDD + 1.246 FHD; p<0.05). The adjusted odds-ratio for DR conferred by higher pulse pressure was 5 (95% CI 2 – 12.8; p<0.05. Conclusion: Longer duration of diabetes, arterial systolic hypertension, and higher pulse pressure (arterial stiffness) were the most significant independent risk factors of diabetic retinopathy. However, a population-based study is warranted to identify the risk factors, as well as the prevalence of diabetic retinopathy.
Keywords: Africans, diabetic retinopathy, prevalence, pulse pressure, risk factors, type-2 diabetes mellitus.
Diabetes mellitus (DM) is a massive problem worldwide with 171 million with the condition today and projected to increase to 360 millions in 2030.1 In Sub-Saharan Africa in general2 and in Democratic Republic of the Congo (DRC) in particular3 the prevalence of DM varies from 1-2% in rural areas to 16% in urban areas. One of the diabetic microvascular complications is diabetic retinopathy (DR) which is defined as damage to microvascular system in the retina due to prolonged hyperglycaemia and is an important cause of blindness in the world.4 However, hospital-based data on DR in African settings are fragmented.5 Because of the large number of diabetic subjects, DR is likely to pose a heavy public health burden in Sub-Saharan Africa. Community-based data on the prevalence and risk factors of DR in Kinshasa, DRC (Central Africa), are lacking. The aim of this study was to determine the prevalence and the risk factors of diabetic retinopathy in urban diabetics from Kinshasa, DRC.