The effect of age, gender, risk level and glycosylated hemoglobin in predicting foot amputation in HMO patients with diabetes

Does Perioperative Hemoglobin A1c Level Affect the Incidence, Pattern and Mortality of Lower Extremity Amputation?

BACKGROUND

We hypothesized that perioperative HbA1c influenced the pattern and outcomes of Lower Extremity Amputation (LEA).

METHODS

A retrospective analysis was conducted for all patients who underwent LEA between 2000 and 2013. Patients were categorized into 5 groups according to their perioperative HbA1c values [Group 1 (<6.5%), Group 2 (6.5-7.4%), Group 3 (7.5-8.4%), Group 4 (8.5-9.4%) and Group 5 (≥9.5%)]. We identified 848 patients with LEA; perioperative HbA1c levels were available in 547 cases (Group 1: 18.8%, Group 2: 17.7%, Group 3: 15.0%, Group 4: 13.5% and Group 5: 34.9%). Major amputation was performed in 35%, 32%, 22%, 10.8% and 13.6%, respectively.

RESULTS

The overall mortality was 36.5%; of that one quarter occurred during the index hospitalization. Mortality was higher in Group 1 (57.4%) compared with Groups 2-5 (46.9%, 38.3%, 36.1% and 31.2%, respectively, p=0.001). Cox regression analysis showed that poor glycemic control (Group 4 and 5) had lower risk of mortality post-LEA [hazard ratio 0.57 (95% CI 0.35-0.93) and hazard ratio 0.46 (95% CI 0.31-0.69)]; this mortality risk persisted even after adjustment for age and sex but was statistically insignificant. The rate of LEA was greater among poor glycemic control patients; however, the mortality was higher among patients with tight control.

CONCLUSION

The effects of HbA1c on the immediate and long-term LEA outcomes and its therapeutic implications need further investigation.

Evidence based review of literature on detriments to healing of diabetic foot ulcers

BACKGROUND

Diabetes mellitus places a substantial burden on society worldwide. Diabetic foot ulcers are a challenging problem for clinicians. Seven generally accepted detriments to healing of diabetic foot ulcers were identified: infection, glycaemic control, vascular supply, smoking, nutrition, deformity and offloading. The aim of this paper is to present a comprehensive evidence based review of the literature available on detriments to healing of diabetic foot ulcers.

METHOD

A research question was generated for each of the detriments to healing and a comprehensive review of the literature was performed using the Pubmed database in July 2014. All articles were assessed for relevancy and a level of evidence was assigned. An analysis of the total body of literature was used to assign a grade of recommendation to each detriment.

RESULTS

Grade A recommendation was assigned to offloading as there was good evidence supporting this intervention. Grade B recommendation was assigned to deformity as there was fair evidence consistent with the hypothesis. Infection and vascular supply had poor quality evidence supporting the research question and grade C recommendation was assigned. Grade I recommendation was assigned to glycaemic control, smoking and nutrition as there was insufficient and conflicting evidence available.

CONCLUSION

Our literature review revealed good evidence for some factors and insufficient literature on others. Further studies are needed to provide quality evidence regarding detriments to healing of diabetic ulcers.

Predictive Laboratory Findings of Lower Extremity Amputation in Diabetic Patients: Meta-analysis

Lower extremity amputation is a source of morbidity and mortality among diabetic patients. This meta-analysis aimed to identify significant laboratory data in patients with diabetic foot ulcer with high rates of lower extremity amputation. We performed a systematic literature review and meta-analysis using MEDLINE, EMBASE, and Cochrane databases. We extracted and evaluated 11 variables from the included studies based on amputation rates. This study used the Newcastle-Ottawa Scale to assess the quality of the studies. The search strategy identified 101 publications from which we selected 16 articles for review. We identified HbA1c, fasting blood glucose, white blood cells, C-reactive protein, and erythrocyte sedimentation rate as predictive variables of higher major amputation rate. Although further investigation of long-term and prospective studies is needed, we identified 5 variables as predisposing factors for higher major amputation in diabetic patients through meta-analysis.

Influence of Epidemiologic and Patient Behavior–Related Predictors on Amputation Rates in Diabetic Patients

Amputation of patients with diabetic foot is a major issue worldwide, particularly from a medical and economic standpoint. This meta-analysis aimed to identify significant risk factors of high amputation rate among epidemiologic and patient behavior–related predictors in diabetic patients. A systematic literature review and meta-analysis were performed using MEDLINE, EMBASE, and Cochrane databases. Seven variables were extracted from the included studies and evaluated based on amputation rate. The Newcastle-Ottawa scale was used to assess the quality of the studies. The search strategy identified 101 publications. After screening, 33 articles were selected for review. Male sex and smoking were identified as significant risk factors of high amputation rate of diabetic foot. Although further investigation of long-term and randomized controlled studies is needed, we identified 2 variables as significant risk factors for high amputation rate in diabetic patients in this meta-analysis.

HbA1c and Lower Extremity Amputation Risk in Patients With Diabetes

In this meta-analysis, we aimed to assess glycosylated hemoglobin (HbA1c) level and lower extremity amputation (LEA) risk in patients with diabetes. Systematic computerized searches of the PubMed and Web of Knowledge were performed. We compared HbA1c level between groups with LEA and without LEA by meta-analysis; we also examined the dose–response relationship between HbA1c level and LEA risk. Sixteen studies were included in the meta-analysis. Eleven studies with 43 566 patients compared HbA1c between groups with and without LEA. The mean HbA1c (%) ranged from 8.3 to 12.5 in the group with LEA and from 7.4 to 11.3 in the group without LEA. The pooled weighted mean difference was 1.110 (95% confidence interval = 0.510-1.709; Z = 3.63, P = .008). The funnel plot was symmetrical, and Begg’s test ( z = 0.00, P = 1.000) and Egger’s test ( t = −0.02, P = .984) suggested no significant publication bias. Six studies with 109 933 patients included in the dose–response meta-analysis. The LEA incidence ranged from 0.3% to 14.6% between different HbA1c levels. Dose–response meta-analysis showed statistically significant association between HbA1c and LEA risk (χ2 = 65.51, P = .000). In linear model, the odds ratio for LEA incidence was 1.229 (95% confidence interval = 1.169-1.292) for every 1% HbA1c increase. In the spline model, the odds ratio of LEA risk increased with HbA1c levels, especially when HbA1c ranged from 5% to 9%. Our meta-analysis indicates that high level of HbA1c is an important risk factor for LEA in patients with diabetes. This evidence supports the strategy for lowering glucose levels to reduce amputation in patients with diabetes.

Classification systems for lower extremity amputation prediction in subjects with active diabetic foot ulcer: a systematic review and meta-analysis

AIM

We systematically review the available systems used to classify diabetic foot ulcers in order to synthesize their methodological qualitative issues and accuracy to predict lower extremity amputation, as this may represent a critical point in these patients' care.

MATERIAL AND METHODS

Two investigators searched, in EBSCO, ISI, PubMed and SCOPUS databases, and independently selected studies published until May 2013 and reporting prognostic accuracy and/or reliability of specific systems for patients with diabetic foot ulcer in order to predict lower extremity amputation.

RESULTS

We included 25 studies reporting a prevalence of lower extremity amputation between 6% and 78%. Eight different diabetic foot ulcer descriptions and seven prognostic stratification classification systems were addressed with a variable (1-9) number of factors included, specially peripheral arterial disease (n = 12) or infection at the ulcer site (n = 10) or ulcer depth (n = 10). The Meggitt-Wagner, S(AD)SAD and Texas University Classification systems were the most extensively validated, whereas ten classifications were derived or validated only once. Reliability was reported in a single study, and accuracy measures were reported in five studies with another eight allowing their calculation. Pooled accuracy ranged from 0.65 (for gangrene) to 0.74 (for infection).

CONCLUSION

There are numerous classification systems for diabetic foot ulcer outcome prediction, but only few studies evaluated their reliability or external validity. Studies rarely validated several systems simultaneously and only a few reported accuracy measures. Further studies assessing reliability and accuracy of the available systems and their composing variables are needed.

Gender differences of lower extremity amputation risk in patients with diabetic foot: a meta-analysis

In this meta-analysis, we aim to evaluate gender differences of lower extremity amputation risk in patients with diabetic foot. Systematic computerized searches of PubMed and Web of Knowledge were performed. The pooled odds ratio (OR) and 95% confidence interval (CI) for amputation risk were calculated. Twenty studies with 15 385 case (present amputation) and 438 760 control (absent amputation) patients were included in the meta-analysis. The pooled crude OR was 1.676 (95% CI 1.307-2.149; Z = 4.07, P = .000). In the retrospective study subgroup, the pooled OR was 1.708 (95% CI = 1.235-2.363; Z = 3.24, P = .001); in the prospective study subgroup, the pooled OR was 1.478 (95% CI = 1.189-1.838; Z = 3.51, P = .000). The pooled adjusted OR was 1.439 (95% CI = 1.238-1.671; Z = 4.76, P = .000). In retrospective study subgroup, the pooled OR was 1.440 (95% CI = 1.208-1.717; Z = 4.07, P = .000); in prospective study subgroup, the pooled OR was 1.478 (95% CI = 1.080-2.024; Z = 2.44, P = .015). No significant publication bias was found. Sensitivity analyses by omitting a heterogeneity study showed the results were robust. In conclusion, our meta-analysis indicates that men with diabetic foot have about one half increased amputation risk than women with diabetic foot. Men with diabetes should receive more complete follow-up and more adequate health education.

Association between glycated haemoglobin and the risk of lower extremity amputation in patients with diabetes mellitus-review and meta-analysis

AIMS/HYPOTHESIS

Diabetes increases the risk of lower extremity amputation (LEA). Although epidemiological studies report positive associations between glycaemia and LEA, the magnitude of the risk is not adequately quantified and clinical trials to date have not provided conclusive evidence about glucose lowering and LEA risk. We synthesised the available prospective epidemiological data on the association between glycaemia measured by HbA(1c) and the risk of LEA in individuals with diabetes.

METHODS

We searched electronic databases and reference lists of relevant articles. We considered prospective epidemiological studies that had measured HbA(1c) level and assessed LEA as an outcome among diabetic individuals without acute foot ulcerations or previous history of amputation. Of 2,548 citations identified, we included 14 studies comprising 94,640 participants and 1,227 LEA cases. We abstracted data using standardised forms and obtained data from investigators when required. Data included characteristics of study populations, HbA(1c) assay methods, outcome and covariates. Study-specific relative risk estimates were pooled using random-effects model meta-analysis; heterogeneity was explored with meta-regression analyses.

RESULTS

The overall RR for LEA was 1.26 (95% CI 1.16-1.36) for each percentage point increase in HbA(1c). There was considerable heterogeneity across studies (I (2) 76%, 67-86%; p < 0.001), which was not accounted for by recorded study characteristics. The estimated RR was 1.44 (95% CI 1.25-1.65) for type 2 diabetes and 1.18 (95% CI 1.02-1.38) for type 1 diabetes; however, the difference was not statistically significant (p = 0.09). We found no strong evidence for publication bias.

CONCLUSIONS/INTERPRETATION

There is a substantial increase in risk of LEA associated with glycaemia in individuals with diabetes. In the absence of conclusive evidence from trials, this paper provides further epidemiological support for glucose-lowering as a strategy to reduce amputation in a population without acute foot ulceration or former amputation; it also provides disease modellers with estimates to assess the overall burden of hyperglycaemia.

Does the proximity of an amputation, length of time between foot ulcer development and amputation, or glycemic control at the time of amputation affect the mortality rate of people with diabetes who undergo an amputation?

OBJECTIVES

The main purpose of the authors' research was to compare the 3- and 5-year mortality rates of diabetic patients who have undergone a lower-extremity amputation, evaluating the proximity of the amputation in 3 groups (toe and foot amputation, BKA, and AKA), the timing of the amputation (within or after 2 years of the onset of the foot ulcer), and the effect of glycemic control at the time of amputation, regardless of the level of amputation.

METHODS AND DESIGN

The subjects were 80 male inpatients at Illiana Veterans Health Care System who had diabetes, diabetic neuropathy, peripheral vascular disease, and a diabetic foot ulcer that resulted in an amputation. Of the 80 patients, 29 had a toe amputation, 30 had a BKA, and 21 had an AKA. The mean age in all 3 groups was 68.5 years+/-7.2 years. The authors used the hemoglobin A1C (Hgb A1C) level to assess glycemic control.

MAIN OUTCOME MEASURES

Several chi tests were used to compare the 3- and 5-year mortality rates among the amputation groups. An Hgb A1C level of 8% or less defined good glycemic control; an Hgb A1C level of more than 8% defined poor glycemic control. A chi test was used to compare glycemic control, the level of amputation, and the mortality rate. A chi test was also used to evaluate the length of time between ulcer formation and amputation, the level of amputation, and the mortality. All statistics were done using SPSS 10.0 student version.

CONCLUSIONS

The research revealed a statistically significant difference in mortality among the 3 groups at 3 and 5 years. No statistically significant difference in mortality in patients with good glycemic control and patients with bad glycemic control was found. At 3 years, a statistically significant difference in mortality existed between patients who had an amputation within 2 years of ulcer formation and those who had an amputation after 2 years. At 5 years, no statistically significant difference existed between these 2 groups.

A case-control study of the risk factors for toe amputation in a diabetic population

Toe amputations are becoming more prevalent in the diabetic population. To prevent toe amputations, those individuals with the highest risk must be identified prior to developing a precipitating event. There are obvious risk factors for toe amputations, such as digital deformity, diabetic neuropathy, and ischemia. Other, less obvious, systemic comorbidities may be linked to toe amputations. This study also shows that gender plays a significant role as a risk factor for toe amputation. A foot infection, foot abscess, osteomyelitis, diabetic retinopathy, and diabetic nephropathy were also significant risk factors for toe amputations. This suggests a significant relationship between these complications and comorbidities that put these individuals at a higher risk for toe amputations.