Determinación del índice tobillo-brazo mediante doppler portátil y tensiómetro automático en pacientes diabéticos

Foot deformities in patients with diabetic mellitus (with and without peripheral neuropathy)

BACKGROUND

Diabetic peripheral neuropathy (DPN) is one of the most common complications in diabetes mellitus. It is the disorder that most commonly affects the feet of people with diabetes. The aim of the present study is to determine the relationship between DPN and the presence of deformities in the foot.

MATERIAL AND METHODS

A descriptive observational study was conducted of 111 patients diagnosed with Diabetes Mellitus (DM) type 1 or 2. All participants were aged at least 18 years and were previously informed in detail about the aims and procedures of the study.

RESULTS

Regarding the presence of DPN, the only significant relationships were found for the right foot with the deformity of the second toe (claw, hammer or mallet) (p = 0.017, OR 0.29 [0.10-0.83]) and for the left foot with the deformity of the second toe (p = 0.048; OR: 0.37 [0.14-1.01]), third toe (p = 0.012; OR: 0.29 [0.11-0.79]) and the presence of hallux extensus (p = 0.05; OR: 8.27 [1.05-64.98]).

CONCLUSIONS

A significant number of foot deformities were observed among these patients with DM, regardless of the presence of DPN. These deformities should be carefully evaluated in order to determine the most appropriate treatment at an early stage, which will reduce the risk of ulceration. Although it should be use with caution to be transferrable to the general population with peripheral neuropathy.

Predictive model to identify the risk of losing protective sensibility of the foot in patients with diabetes mellitus

Diabetic neuropathy is defined as the presence of symptoms and signs of peripheral nerve dysfunction in diabetics. The aim of this study is to develop a predictive logistic model to identify the risk of losing protective sensitivity in the foot. This descriptive cross-sectional study included 111 patients diagnosed with diabetes mellitus. Participants completed a questionnaire designed to evaluate neuropathic symptoms, and multivariate analysis was subsequently performed to identify an optimal predictive model. The explanatory capacity was evaluated by calculating the R² coefficient of Nagelkerke. Predictive capacity was evaluated by calculating sensitivity, specificity, and estimation of the area under the receiver operational curve. Protective sensitivity loss was detected in 19.1% of participants. Variables associated by multivariate analysis were: educational level (OR: 31.4, 95% CI: 2.5-383.3, P = .007) and two items from the questionnaire: one related to bleeding and wet socks (OR: 28.3, 95% CI: 3.7-215.9, P = .001) and the other related to electrical sensations (OR: 52.9, 95% CI: 4.3-643.9, P = .002), which were both statistically significant. The predictive model included the variables of age, sex, duration of diabetes, and educational level, and it had a sensitivity of 81.3% and a specificity of 95.5%. This model has a high predictive capacity to identify patients at risk of developing sensory neuropathy.

Spectrum effect and spectrum bias in the oscillometric ankle brachial index to diagnose peripheral arterial disease: Clinical implications

BACKGROUND AND AIMS

The diagnostic performance of the oscillometric ankle brachial index (ABI) to detect peripheral arterial disease (PAD) varies among populations, suggesting a spectrum effect. When this heterogeneity modifies post-test probabilities, a spectrum bias arises. This study evaluates the presence and influence of spectrum effect and spectrum bias on test performance and clinical decisions.

METHODS

Oscillometric and Doppler ABI were compared in two settings: Primary-Care (333 legs) and Vascular-Service (41 legs). Spectrum effect was assessed using stratification and logistic regression, while spectrum bias was assessed through graphical and statistical tests based on predictive values and likelihood ratios, respectively.

RESULTS

Across subgroups, sensitivity ranged from 61.5% to 90.9%, and specificity from 81.8% to 99.1%. Logistic regression confirmed a spectrum effect in setting, diabetes, smoking status and age (univariate), and setting and diabetes (multivariate model). The positive likelihood ratio ranged from 5.0 to 89.1 in subgroups, leading to a spectrum bias in diabetic, smoking (both subgroups) and age (both subgroups). Therefore, a positive test ruled in differently the disease across subgroups, with a high rate of false positives in diabetic, smoking and >75-year-old patients. The negative likelihood ratio ranged from 0.09 to 0.39 in subgroups, with significant spectrum bias in Primary-Care patients, non-diabetics and smokers. Thus, in these subgroups, a negative test ruled out the disease with less certainty.

CONCLUSIONS

Spectrum effect and spectrum bias were found in oscillometric ABI to detect PAD, potentially affecting clinical decisions, especially for positive tests. Information about spectrum variables and the application of specific subgroups indicators are necessary.

The accuracy of an oscillometric ankle-brachial index in the diagnosis of lower limb peripheral arterial disease: A systematic review and meta-analysis

INTRODUCTION

Peripheral arterial disease (PAD) remains underdiagnosed and undertreated, partly because of limitations in the Doppler ankle-brachial index (ABI), the non-invasive gold standard.

OBJECTIVE

This systematic review and meta-analysis aims to compare the diagnostic accuracy of the oscillometric ABI and the Doppler ABI, and to examine the influence of two approaches to analysis: legs vs subjects and inclusion of oscillometric errors as PAD equivalents vs exclusion.

METHODS

Systematic searches in EMBASE, MEDLINE, Web of Science and the Cochrane Library databases were performed, from inception to February 2017. Random-effects models were computed with the Moses-Littenberg constant. Hierarchical summary receiver operating characteristic curves (HSROC) were used to summarise the overall test performance.

RESULTS

Twenty studies (1263 subjects and 3695 legs) were included in the meta-analysis. The pooled diagnostic odds ratio (dOR) for the oscillometric ABI was 32.49 (95% CI: 19.6-53.8), with 65% sensitivity (95% CI: 57-74) and 96% specificity (95%CI: 93-99). In the subgroup analysis, the "per subjects" group showed a better performance than the "per legs" group (dOR 36.44 vs 29.03). Similarly, an analysis considering oscillometric errors as PAD equivalents improved diagnostic performance (dOR 31.48 vs 28.29). The time needed for the oscillometric ABI was significantly shorter than that required for the Doppler ABI (5.90 vs 10.06 minutes, respectively).

CONCLUSIONS AND RELEVANCE

The oscillometric ABI showed an acceptable diagnostic accuracy and feasibility, potentially making it a useful tool for PAD diagnosis. We recommend considering oscillometric errors as PAD equivalents, and a "per subject" instead of a "per leg" approach, in order to improve sensitivity. Borderline oscillometric ABI values in diabetic population should raise concern of PAD.