Obesity Linked to Worse AVF Access Maturation Outcomes

Increasing obesity class is associated with increased arteriovenous fistulae (AVF) access maturation procedures and poorer dialysis site functionality, according to study findings published in the Journal of Vascular Surgery.

Long-term arteriovenous access is essential in treating patients with kidney failure. Although a higher body mass index (BMI) has been associated with lower mortality rates among hemodialysis patients, prior studies have linked obesity to adverse outcomes in access creation and maintenance, such as worse long-term fistula survival.

To assess the clinical outcomes of AVF in patients with and without obesity, researchers conducted a single-center, retrospective review of all patients with primary upper extremity autogenous AVFs from January 1999 to December 2019.

The researchers assigned patients into 4 categories based on BMI:

• Non-Obese (<30 kg/m²);
• Class I (30.0-34.9 kg/m²);
• Class II (35.0-39.9 kg/m²); and,
• Class III (>40 kg/m²).

The review covered patient information regarding successful progression to hemodialysis (maturation), re-intervention, continuous hemodialysis for 3 months (functional dialysis), and patency.

Exclusion criteria included percutaneous AVF placement, prior AVF revisions, or an arterio-venous graft located on the same extremity. 

The primary outcomes were time to maturation and functional dialysis. Secondary outcomes included dialysis site functionality duration and access patency.

The trial consisted of 2291 patients (mean age, 61 years; SD, 15 years) of whom 67% were women. The non-obese, Class I, Class II, and Class III obesity groups contained 41%, 29%, 19%, and 11% of patients, respectively. The researchers noted no major differences in statin or antiplatelet use between the BMI groups. 

As the category of obesity increased, the proportion of access-related complications within 90 days of the procedure increased (non-obese, 22.5%; Class I, 34.0%; Class II, 50.8%; Class III, 78.2%; P=.001).

Compared with patients in the Class I obesity (5%) and non-obese (3%) groups, those in Class II (9%) and Class III (12%) obesity groups had a higher risk of early thrombosis.

The researchers identified a two-fold increase in procedures to facilitate access maturation in the Class II (51%) and Class III (74%) obesity groups compared with the non-obese (34%) and Class I obesity (22%) groups. Multivariate analysis revealed associations between maturation procedures and Class II (HR, 1.8; 95% CI, 1.1-2.7; P=.03) and Class III (HR, 2.5; 95% CI, 1.1-3.7; P=.02) obesity groups.

Compared with patients in the Class II (79%; SD, 3%) and Class III (62%; SD, 4%) obesity groups, those in the Class I obesity (87%; SD, 2%) and non-obese (93%; SD, 4%) groups showed greater 3-year rates of secondary patency. 

Study limitations included its occurrence at a single-center, the predominantly Hispanic population, and the low placement of grafts within its population.

According to the researchers, “Increasing obesity class is associated with an increased number of procedures to achieve AVF maturation and is associated with poorer patency and functionality as the category of obesity increases.”

This article originally appeared on Endocrinology Advisor