Clinical characteristics and survival of patients with diabetes mellitus following non-traumatic lower extremity amputation.

BACKGROUND: Diabetes mellitus-related lower extremity amputation is a major complication severely affecting patient survival and quality of life. OBJECTIVES: To analyze epidemiological and clinical trends in the incidence and survival of lower extremity amputations among diabetes patients. METHODS: We conducted a retrospective observational cohort study of 565 consecutive diabetes patients who underwent their first non-traumatic lower extremity amputation between January 2002 and December 2009. RESULTS: Major amputations were performed in 316 (55.9%) patients: 142 above the knee (25.1%) and 174 below (30.8%); 249 (44.1%) had a minor amputation. The incidence rates of amputations decreased from 2.9 to 2.1 per 1000 diabetes patients. Kaplan-Meier survival analysis showed that first year mortality rates were lower among patients with minor amputations (31.7% vs. 39.6%, P = 0.569). First year mortality rates following below-knee amputation were somewhat lower than above-knee amputation (33.1 vs. 45.1%, respectively). Cox regression model of survival at 1 year after the procedure found that age (HR 1.06 per year, 95% CI 1.04-1.07, P < 0.001), above-knee amputation (HR 1.36, 95% CI 1.01-1.83, P = 0.045) and ischemic heart disease (HR 1.68, 95% CI 1.26-2.24, P < 0.001) significantly increased one year mortality risk. CONCLUSIONS: In this population-based study the incidence rate of non-traumatic amputations in diabetes patients between January 2002 and December 2009 decreased slightly. However, one year mortality rates after the surgery did not decline and remained high, stressing the need for a multidisciplinary effort to prevent amputations in diabetes patients.

Circulating cell-free DNA in hemodialysis patients predicts mortality.

BACKGROUND: Circulating cell-free DNA (CFD) appears following cell damage and DNA release, and increases in hemodialysis (HD) patients particularly following HD. We hypothesized that CFD is an integrative marker of tissue damage and can be an independent predictor for all-cause mortality in HD patients. METHODS: In a prospective study, CFD levels before and after HD were evaluated in 31 chronic HD patients with no acute disease, using the reported rapid non-cumbersome inexpensive fluorometric assay developed in our laboratory. Follow-up levels were assessed at 18 months in 22 patients. All-cause mortality was a primary endpoint. RESULTS: During 42 months of follow-up, 13 of the 31 (41.9%) patients died. The decedents were older than the survivors (mean age 69.9 versus 61.5 years, P = 0.06), but did not differ in end-stage renal disease (ESRD) duration, gender, albumin and hemoglobin, diabetes mellitus and weight. Post-dialysis CFD levels were significantly lower in survivors (median 688 versus 880 ng/mL, P = 0.01). The sensitivity and specificity of CFD levels of 850 ng/mL to predict 42 months (3.5 years) mortality were 73 and 75%, respectively, and the area under the receiver-operating characteristic curve was 0.77 [95% confidence interval (CI) 0.60-0.94]. The Cox proportional hazard regression model showed that CFD higher than 850 ng/mL adjusted for age, ESRD duration, weight and creatinine (stepwise model) was highly predictive of all-cause death with a hazard ratio of 8.0 (95% CI 2.3-28.5, P = 0.001). CONCLUSIONS: Post-dialysis CFD level is an independent predictor of all-cause mortality in patients undergoing HD. We propose that CFD detection is an inexpensive applicable tool for identifying patients at risk and their follow-up.