Quantitative sensory testing defines the trajectory of sensory neuropathy after severe COVID-19.

AIMS: To assess sensory neuropathy development after severe COVID-19. METHODS: Patients with severe COVID-19 underwent assessment of neuropathic symptoms, tendon reflexes, and quantitative sensory testing to evaluate vibration (VPT), cold (CPT), warm (WPT) and heat perception thresholds (HPT) within 1-3 weeks of admission and after 1-year. RESULTS: 32 participants with severe COVID-19 aged 68.6 ± 12.4 (18.8 % diabetes) were assessed. At baseline, numbness and neuropathic pain were present in 56.3 % and 43.8 % of participants, respectively. On the feet, VPT, WPT, and HPT were abnormal in 81.3 %, CPT was abnormal in 50.0 % and HPT on the face was abnormal in 12.5 % of patients. At 1-year follow-up, the prevalence of abnormal VPT (81.3 % vs 50.0 %, P < 0.01), WPT (81.3 % vs 43.8 %, P < 0.01), and HPT (81.3 % vs 50.0 %, P < 0.01) decreased, with no change in CPT (P = 0.21) on the feet or HPT on the face (P = 1.0). Only participants without diabetes recovered from an abnormal VPT, CPT, and WPT. Patients with long-COVID (37.5 %) had comparable baseline VPT, WPT and CPT with those without long-COVID (P = 0.07-0.69). CONCLUSIONS: Severe COVID-19 is associated with abnormal vibration and thermal thresholds which are sustained for up to 1 year in patients with diabetes. Abnormal sensory thresholds have no association with long-COVID development.

Widespread sensory neuropathy in diabetic patients hospitalized with severe COVID-19 infection.

AIMS: To characterize the distribution and severity of sensory neuropathy using a portable quantitative sensory testing (QST) device in diabetic patients (DM) hospitalized with severe COVID-19 infection. METHODS: Four patients with diabetes and severe SARS-CoV-2 requiring non-invasive ventilation for a protracted duration underwent clinical, laboratory and radiologic assessment and detailed evaluation of neuropathic symptoms, neurological assessment, QST on the dorsum of the foot and face using NerveCheck Master with assessment of taste and smell. RESULTS: All four subjects developed neuropathic symptoms characterized by numbness in the feet with preserved reflexes. QST confirmed symmetrical abnormality of vibration and thermal thresholds in both lower limbs in all patients and an abnormal heat pain threshold on the face of two patients and altered taste and smell. CONCLUSIONS: Severe COVID-19 infection with hypoxemia is associated with neuropathic symptoms and widespread sensory dysfunction in patients with DM.

Iron deficiency is a key determinant of health-related quality of life in patients with chronic heart failure regardless of anaemia status.

AIMS: To evaluate the effect of iron deficiency (ID) and/or anaemia on health-related quality of life (HRQoL) in patients with chronic heart failure (CHF). METHODS AND RESULTS: We undertook a post-hoc analysis of a cohort of CHF patients in a single-centre study evaluating cognitive function. At recruitment, patients provided baseline information and completed the Minnesota Living with Heart Failure questionnaire (MLHFQ) for HRQoL (higher scores reflect worse HRQoL). At the same time, blood samples were taken for serological evaluation. ID was defined as serum ferritin levels <100 ng/mL or serum ferritin <800 ng/mL with transferrin saturation <20%. Anaemia was defined as haemoglobin ≤12 g/dL. A total of 552 CHF patients were eligible for inclusion, with an average age of 72 years and 40% in NYHA class III or IV. The MLHFQ overall summary scores were 41.0 ± 24.7 among those with ID, vs. 34.4 ± 26.4 for non-ID patients (P = 0.003), indicating worse HRQoL. When adjusted for other factors associated with HRQoL, ID was significantly associated with worse MLHFQ overall summary (P = 0.008) and physical dimension scores (P = 0.002), whereas anaemia was not (both P > 0.05). Increased levels of soluble transferrin receptor were also associated with impaired HRQoL (P ≤ 0.001). Adjusting for haemoglobin and C-reactive protein, ID was more pronounced in patients with anaemia compared with those without (P < 0.001). CONCLUSION: In patients with CHF, ID but not anaemia was associated with reduced HRQoL, mostly due to physical factors.

Iron deficiency in chronic heart failure: an international pooled analysis.

BACKGROUND: Iron deficiency (ID) is an emerging problem in patients with chronic heart failure (HF) and can be a potential therapeutic target. However, not much is known about the prevalence, predictors, and prognosis of ID in patients with chronic HF. METHODS: In an international pooled cohort comprising 1,506 patients with chronic HF, we studied the clinical associates of ID and its prognostic consequences. RESULTS: Iron deficiency (defined as a ferritin level <100 µg/L or ferritin 100-299 µg/L with a transferrin saturation <20%) was present in 753 patients (50%). Anemic patients were more often iron deficient than nonanemic patients (61.2% vs 45.6%, P < .001). Other independent predictors of ID were higher New York Heart Association class, higher N-terminal pro-brain-type natriuretic peptide levels, lower mean corpuscular volume levels, and female sex (all P < .05). During follow-up (median 1.92 years, interquartile range 1.18-3.26 years), 440 patients died (29.2%). Kaplan-Meier survival analysis revealed ID as a strong predictor for mortality (log rank χ(2) 10.2, P = .001). In multivariable hazard models, ID (but not anemia) remained a strong and independent predictor of mortality (hazard ratio 1.42, 95% confidence interval 1.14-1.77, P = .002). Finally, the presence of ID significantly enhanced risk classification and integrated discrimination improvement when added to a prediction model with established risk factors. CONCLUSIONS: Iron deficiency is common in patients with chronic HF, relates to disease severity, and is a strong and independent predictor of outcome. In this study, ID appears to have greater predictive power than anemia.