Prevalence of peripheral arterial disease in patients with type 2 diabetes mellitus (a comparative study between patients of Asian and African ethnicities in Dar es salaam, Tanzania)

Abstract

Background: The worldwide prevalence of lower extremity peripheral artery disease (PAD) is between 3-12%. In 2010, 202 million people around the world were living with PAD. In Europe and North America, an estimated 27 million individuals are affected with approximately 413,000 inpatient admissions annually attributed to PAD. The majority of individuals with PAD (70%) live in low/middle income regions of the world. Diabetes Mellitus, together with smoking, is the main risk factor for PAD. Despite this, the current prevalence of PAD in Tanzania remains unknown. Different studies have identified various risk factors for adverse outcomes such as poorly-healing diabetic foot ulcers, critical limb ischemia and lower limb amputations as feared complications of PAD, and hence early detection and intervention of the disease would significantly help to reduce morbidity and mortality among people living with the disease.

Objective: To determine and compare the prevalence and factors associated with PAD among Type 2 diabetes mellitus patients of Asian and African ethnicities in Dar-es-Salaam.

Methodology: A descriptive cross-sectional study was conducted at the Diabetes Clinic at Shree Hindu Mandal Hospital between September and December 2016. 367 patients (189 Africans and 178 Asians) with T2DM who are attending the clinic were consecutively enrolled. Data was collected using a structured questionnaire. The Ankle-Brachial Index (ABI) determination using a Huntleigh Dopplex MD2 bidirectional doppler was done to assess peripheral arterial circulation, patients were categorized as having normal or abnormal ABI according to standard ABI scores (<0.9 and >1.3 being considered as abnormal), along with determination of laboratory values of glycated hemoglobin and lipid profile (serum values of triglycerides, HDL, LDL and total cholesterol). Logistic regression was performed to determine the effect of various predictors on peripheral arterial circulation.

Results: Of the 368 recruited type 2 diabetic subjects, 112 (30.7%) were found to have peripheral arterial disease; 71 Africans (38%) and 41 Asians (23%); showing a higher prevalence of the disease in the African ethnicity. Symptomatic PAD was observed in two-thirds of the detected patients. In both ethnicities, an age of over 45 years, a duration of T2DM of more than 10 years (Asians: AOR 2.0 (95% CI 1.1-3.8), Africans: AOR 2.5 (95% CI 1.0-6.2)),suboptimal-poor glycemic control represented by HbA1c level of >7% (Asians: AOR 6.5 (95% CI 2.3-18.5), Africans: AOR 12.6 (95% CI 2.9-53.8)) and a history of leg pain (Asians: AOR 4.3 (95% CI 2.2-8.2), Africans: AOR 2.2 (95% CI 1.0-4.9) were observed as strong determinants of PAD, and additionally for the African ethnicity, a raised level of serum total cholesterol was seen as a strong determinant of PAD (AOR 4.0(95% CI 1.2-13.2)).

Conclusion and Recommendations: This study explicitly reveals that there is a higher prevalence of PAD in type 2 diabetics of African ethnicity as compared those of the Asian ethnicity. This study should prompt care-givers to screen any diabetic patient with an older age, or duration of DM for more than 10 years, or with poor glycemic control or a history of any form leg pain for PAD. This will allow timely appropriate measures to be taken to reduce the health and economic burden of PAD complications.