The influence of metabolic syndrome on hemodialysis access patency

Abstract

Objective: The natural history of patients with metabolic syndrome (MetS) undergoing hemodialysis access placement is unknown. MetS has previously been found as a risk factor for poor outcomes for vascular surgery patients undergoing other interventions. The aim of this is study is to describe the outcomes of MetS patients undergoing primary hemodialysis access placement.

Methods: The medical records of the 187 patients who underwent hemodialysis access placement between 1999 and 2009 at the Veterans Administration Connecticut Healthcare System were reviewed. Survival, primary patency, and secondary patency were evaluated using the Gehan-Breslow test for survival. MetS was defined as the presence of three or more of the following: blood pressure≥130/90 mm Hg; triglycerides≥150 mg/dL; high-density lipoprotein≤50 mg/dL for women and ≤40 mg/dL for men; body mass index≥30 kg/m2; or fasting blood glucose≥110 mg/dL.

Results: Of the 187 patients who underwent hemodialysis access placement, 115 (61%) were identified to have MetS. The distribution of MetS factors among all patients was hypertension in 98%, diabetes in 58%, elevated triclyceride in 39%, decreased high-density lipoprotein in 60%, elevated body mass index in 36%, and 39% were currently receiving hemodialysis. Patients were a mean age of 66 years. The median length of follow-up was 4.2 years. The forearm was site of fistula placement in 53%; no difference existed between groups (MetS, 57%; no MetS, 50%; P=.388). The median time to primary failure was 0.46 years for all patients (MetS, 0.555 years; no MetS, 0.436 years; P=.255). Secondary patency was 50% at 1.18 years for all patients (no MetS, 1.94 years; MetS, 0.72 years; P=.024). Median survival duration for all patients was 4.15 years (no MetS, 5.07 years; MetS, 3.63 years; P=.019).

Conclusions: MetS is prevalent among patients undergoing hemodialysis access placement. Patients with MetS have equivalent primary patency rates; however, their survival and cumulative patency rates are significantly lower than in patients without MetS. Patients with MetS form a high-risk group that needs intensive surveillance protocols.

Figure I

Survival. For all patients, the 6-month, 12-month, and 24-month survival rates are 93%, 87%, and 73%, respectively. By Kaplan-Meier analysis, MetS patients experienced decreased freedom from secondary patency failure. Error bars are omitted for clarity. Standard error did not exceed 10% at all time intervals analyzed.

Figure II

Freedom from Primary Patency Failure. For all patients, the 6-month, 12-month, and 24-month freedom from primary patency failure is 47%, 24%, and 8%, respectively. No difference identified between groups. Error bars are omitted for clarity. Standard error did not exceed 10% at all time intervals analyzed.

Figure III

Freedom from Secondary Patency Failure. For all patients, the 6-month, 12-month, and 24-month freedom from primary patency failure is 69%, 53%, and 38%, respectively. By Kaplan-Meier analysis, MetS patients experienced decreased freedom from secondary patency failure. Error bars are omitted for clarity. Standard error did not exceed 10% at all time intervals analyzed.