White Coat Hyperglycemia: The Forgotten Syndrome

Characterization of Artifact Influence on the Classification of Glucose Time Series Using Sample Entropy Statistics

This paper analyses the performance of SampEn and one of its derivatives, Fuzzy Entropy (FuzzyEn), in the context of artifacted blood glucose time series classification. This is a difficult and practically unexplored framework, where the availability of more sensitive and reliable measures could be of great clinical impact. Although the advent of new blood glucose monitoring technologies may reduce the incidence of the problems stated above, incorrect device or sensor manipulation, patient adherence, sensor detachment, time constraints, adoption barriers or affordability can still result in relatively short and artifacted records, as the ones analyzed in this paper or in other similar works. This study is aimed at characterizing the changes induced by such artifacts, enabling the arrangement of countermeasures in advance when possible. Despite the presence of these disturbances, results demonstrate that SampEn and FuzzyEn are sufficiently robust to achieve a significant classification performance, using records obtained from patients with duodenal-jejunal exclusion. The classification results, in terms of area under the ROC of up to 0.9, with several tests yielding AUC values also greater than 0.8, and in terms of a leave-one-out average classification accuracy of 80%, confirm the potential of these measures in this context despite the presence of artifacts, with SampEn having slightly better performance than FuzzyEn.

Assessing performance in pre-season wrestling athletes using biomarkers

Introduction

Although regular training introduces the desired changes in athletes' metabolism towards optimal final performance, literature is rarely focusing on the metabolic responses off-competition. Therefore, the aim of this study was to evaluate biochemical indices during typical preseason training in wrestling athletes.

Materials and methods

Twenty male freestyle and Greco-roman wrestlers (14 to 31 years) followed a typical session of the preparatory phase. Capillary blood glucose and lactate concentrations were assessed immediately before and after training. Protein, microalbumin, creatinine and their ratio were estimated the next day in the first morning urine.

Results

Pre-training lactate concentrations were lower in Greco-roman than in freestyle wrestlers (1.8 (1.4 - 2.1) vs. 2.9 (2.1 - 3.1) mmol/L). Exertion resulted in a significant increase in lactate concentrations, by 3.2 (2.6 - 4.1) mmol/L in Greco-roman wrestlers and 4.5 (3.4 - 5.3) mmol/L in freestylers. These changes were found to correlate with athlete's sport experience (r_s = 0.71, P < 0.001). Glucose concentrations were also significantly increased by 0.5 (0.1 - 0.8) mmol/L, in correlation with lactate change (r_s = 0.49, P = 0.003). Twelve subjects exhibited urine albumin concentrations at 30 mg/L, and thirteen creatinine concentrations around 17.7 mmol/L. The corresponding ratio was found abnormal in 4 cases, especially when creatinine excretion and body fat were low.

Conclusions

Wrestling training is associated with mobilization of both lactic and alactic anaerobic energy systems. The regular comprehensive monitoring of biochemical markers would be advantageous in determining the efficiency of the preparatory phase and the long-term physiological adaptations towards the competition phase, or athlete's overtraining.