# Exploratory Study on the Prevalence of Peripheral Artery Disease in Asymptomatic Patients With Diabetes and Hypertension in a Family Health Unit

## TL;DR

This study found a 5.5% prevalence of asymptomatic peripheral artery disease in patients with diabetes or hypertension, highlighting risk factors like high abdominal fat and long-term hypertension.

## Contribution

The study provides new prevalence data for asymptomatic LEAD in a Portuguese primary care population with diabetes and hypertension.

## Key findings

- The prevalence of asymptomatic LEAD was 5.5% in the studied population.
- Higher abdominal circumference, longer hypertension duration, and elevated LDL levels were significant predictors of LEAD.
- The use of the Cockcroft-Gault equation overestimated GFR in the LEAD group due to body composition biases.

## Abstract

Introduction: Lower extremity artery disease (LEAD) represents a manifestation of atherosclerosis, with the majority of affected individuals remaining asymptomatic. Whether asymptomatic or not, LEAD is associated with a three- to six-fold increased risk of cardiovascular mortality, underscoring the importance of early intervention. The ankle-brachial index (ABI) is a recommended screening tool for LEAD, with a diagnostic threshold defined as an ABI of ≤0.90. Patients with arterial hypertension and/or diabetes mellitus (DM) are at elevated risk for developing LEAD, yet systematic screening for this condition is lacking in this population. The primary objective was to determine the prevalence of asymptomatic LEAD in patients with arterial hypertension and/or DM, while the secondary objective was to identify the main predictors of LEAD in this population.

Materials and methods: This was an exploratory, observational, cross-sectional study involving a random sample of patients with DM and/or arterial hypertension enrolled in a family health unit (FHU), aged 50 to 66 years, without very high cardiovascular risk (CVR) or symptoms of LEAD. ABI was measured, and LEAD was diagnosed if ABI ≤0.90. Statistical analyses were performed using SPSS® software.

Results: The study included 146 patients, of whom 134 had arterial hypertension, and 68 had DM, with a mean age of 59.5±4.2 years. Eight patients were diagnosed with LEAD, yielding a prevalence of 5.5%. Statistically significant differences were observed between the groups with and without LEAD in the following variables: abdominal circumference (p=0.043), glomerular filtration rate (GFR) using Cockcroft-Gault (CG) equation (p=0.024), duration of arterial hypertension (p=0.024), and LDL levels (p=0.014), with higher medians in the LEAD group.

Discussion: There are several studies calculating the prevalence of LEAD, but variations in study populations make direct comparisons challenging. The LEAD group showed higher abdominal circumference, longer hypertension duration, and elevated LDL cholesterol, consistent with existing literature. However, the significantly higher GFR observed in this group using the CG equation was unexpected. This may be explained by the inclusion of body weight in the CG formula, which can overestimate GFR in individuals with central obesity due to increased fat mass rather than increased renal function. Conversely, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, which does not incorporate body weight, showed no significant difference in GFR between groups, supporting the hypothesis that CG estimates were biased by body composition. Regarding limitations, this study possibly had information and inter-observer bias, a lack of confirmation of diagnosis by imaging study, as well as an under-representation of smokers, an important risk factor for LEAD, which may have influenced the calculation of prevalence.

Conclusion: The prevalence of asymptomatic LEAD in patients with DM and/or arterial hypertension within our sample was 5.5%. The results suggest that patients with higher abdominal circumference, longer duration of arterial hypertension, and elevated LDL are at increased risk for LEAD, supporting the prioritization of this population for screening. However, further studies are essential to better define the optimal target population for LEAD screening in Portugal.