Hypoandrogenemia, a frequent finding in men with obesity, is defined by low concentrations of serum testosterone. Although immunoassay (IA) is the most used method for the determination of this steroid in clinical practice, liquid chromatography-mass spectrometry (LC-MS/MS) is considered a more reliable method. In this study, we aimed to compare IA versus LC-MS/MS measurement for the diagnosis of hypoandrogenemia in a cohort of 273 nondiabetic young obese men. Mean total testosterone (TT) levels were 3.20 ± 1.24 ng/mL for IA and 3.78 ± 1.4 ng/mL for LC-MS/MS. 53.7% and 26.3% of patients were classified as presenting hypoandrogenemia with IA and LC-MS/MS, respectively. Considering LC-MS/MS as the reference method, sensitivity and specificity of IA were 91.4% (95% CI 82.3–96.8) and 61.1% (95% CI 54.0–67.8), respectively. IA presented an AUC of 0.879 (95% CI 0.83–0.928). Multivariate regression analysis indicated that sex hormone-binding globulin (SHBG) concentrations (p = 0.002) and insulin resistance (p = 0.008) were factors associated with discrepant IA values. In conclusion, the determination of TT by IA in nondiabetic young men with obesity yields lower concentrations of TT than LC-MS/MS, resulting in an equivocal increased diagnosis of hypoandrogenemia, which could lead to inaccurate diagnosis and unnecessary treatment.

Objectives Remote self-collected capillary blood samples have been proposed as alternative to venous blood samples as an aid in telemedicine. The aim of this work is to compare the preanalytical and analytical performance of these two types of samples and to study the stability of common measurands in capillary blood. Methods Capillary and venous blood samples were collected in parallel from 296 patients in serum tubes to analyze 22 common biochemistry magnitudes after centrifugation and in EDTA tubes to analyze 15 hematologic magnitudes. Quality of the preanalytical process was assessed applying the model of quality indicator. 24 h stability at room temperature was studied by obtaining paired capillary samples. A questionnaire of assessment was conducted. Results Mean hemolysis index was higher in capillary samples compared to venous blood samples (p<0.001). Regression analysis and difference analysis showed no bias for all studied biochemistry parameters and hematologic parameters, except mean corpuscular volume (MCV), between capillary and venous blood samples. Regarding sample stability, percentage deviation was higher than the corresponding minimum analytical performance specification for ferritin, vitamin D, hematocrit, MCV, mean corpuscular hemoglobin concentration, platelets distribution wide, mean platelet volume and basophils. Finger pricking was perceived as less painful (p<0.05) than venipuncture in participants who undergo more than one blood test per year. Conclusions Capillary blood can be used as an alternative to venous blood for the studied parameters in automated common clinical analyzers. Cautious should be taken if samples are not analyzed within 24 h from the collection.

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