Iron in kidney and heart failure: from theory to practice

Effect of sodium-glucose cotransporter 2 inhibitors on hemoglobin and hematocrit levels in type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve outcomes of patients with type 2 diabetes at high cardiovascular risk and chronic kidney disease. Recent studies showed an increase in hemoglobin and hematocrit after SGLT2i treatment.

MATERIALS AND METHODS

We did a systematic review and meta-analysis of randomized, double-blind, placebo-controlled studies of SGLT2i in patients with type 2 diabetes. We searched through PubMed/Medline, Web of Science, Embase (Elsevier), and the Cochrane Central Register of Controlled Trials (Wiley) from January 2010 to January 2021.

RESULTS

We included seventeen randomized, double-blind, placebo-controlled studies. The total number of evaluated patients was 14,748. The treatment arm consisted of canagliflozin, dapagliflozin, empagliflozin and ipragliflozin. SGLT2i therapy significantly increased hemoglobin levels when compared to placebo (MD 5.60 g/L, 95% CI 3.73-7.47 g/L, P < 0.00001, considerable heterogeneity-I² = 94%). Each SGLT2i also led to a significant increase in the hematocrit level when compared to placebo (MD 1.32%, 95% CI 1.21-1.44, P < 0.00001, considerable heterogeneity-I² = 99%).

CONCLUSIONS

SGLT2i led to significant increases in hemoglobin and hematocrit levels when compared to placebo. In addition to their cardiovascular effect, SGLT2i also increases hemoglobin and hematocrit levels.

Efficiency of Hypertonic Saline in the Management of Decompensated Heart Failure: A Systematic Review and Meta-Analysis of Clinical Studies

INTRODUCTION

Acute decompensated heart failure (ADHF), with an incidence of 1-2%, is a clinical syndrome with significant morbidity and mortality despite therapeutic advancements and ongoing clinical trials. A recent therapeutic approach to patients with ADHF includes combination therapy with hypertonic saline solution (HSS) and furosemide, based on the hypothesis that resistance to loop diuretics occurs because of achievement of plateau in water and sodium excretion in patients receiving long-term loop diuretic therapy.

OBJECTIVE

Our aim was to conduct a meta-analysis to evaluate the efficiency of combination HSS plus furosemide therapy in patients with ADHF in terms of mortality, readmissions, length of hospital stay, kidney function, urine output, body weight, and B-type natriuretic peptide (BNP).

METHODS

A total of 14 studies-four observational and ten randomized studies (total 3398 patients)-were included in the meta-analysis.

RESULTS

Our results demonstrate the superiority of combination HSS plus furosemide therapy over furosemide alone in terms of kidney function preservation (mean creatinine difference - 0.33 mg/dL; P < 0.00001), improved diuresis (mean difference [MD] 581.94 mL/24 h; P < 0.00001) and natriuresis (MD 57.19; P < 0.00001), weight loss (MD 0.99 kg; P < 0.00001), duration of hospital stay (MD - 2.72 days; P < 0.00001), readmissions (relative risk 0.63; P = 0.01), and mortality (relative risk 0.55; P < 0.00001). However, no difference in BNP levels was detected (MD 19.88 pg/mL; P = 0.50).

CONCLUSION

Despite the heterogeneity and possible risk of bias among the studies, results appear promising on multiple aspects. A clear need exists for future randomized controlled trials investigating the role of combination HSS plus furosemide therapy to clarify these effects and their possible mechanisms.

A journey from microenvironment to macroenvironment: the role of metaflammation and epigenetic changes in cardiorenal disease

Chronic non-communicable diseases have become a pandemic public problem in the 21st century, causing enormous burden on the economy, health and quality of life of societies. The role of a chronic inflammatory state in the pathogenesis of chronic disease has been more comprehensively recognized by recent findings. The new paradigm ‘metaflammation’ focuses on metabolism-induced (high fat or fructose-based diet or excessive calorie intake) chronic inflammation. There is a close correlation between the increased incidence of chronic kidney disease (CKD) and chronic heart failure with both increased inflammatory marker levels and western-type diet. In this review we describe the concept of metaflammation, its role in the development of CKD and chronic heart disease, the molecular and signalling pathways involved and the therapeutic consequences.

Iron deficiency in heart failure

: Due to aging of the patients with heart failure, comorbidities are an emerging problem and, among them, iron deficiency is an important therapeutic target, independently of concomitant hemoglobin level. Iron deficiency affects up to 50% of heart failure patients, and it has been largely established its association with poor quality of life, impaired exercise tolerance and higher mortality. Randomized controlled trials (RCTs) and meta-analyses have demonstrated that intravenous iron supplementation in heart failure patients with iron deficiency positively affects symptoms, quality of life, exercise tolerance (as measured by VO2 peak and 6MWT), with a global trend to reduction of hospitalization rates. Current European Society of Cardiology Guidelines for heart failure recommend a diagnostic work-up for iron deficiency in all heart failure patients and intravenous iron supplementation with ferric carboxymaltose for symptomatic patients with iron deficiency, defined by ferritin level less than 100 μg/l or by ferritin 100-300 μg/l with TSAT less than 20%. On-going studies will provide new evidence for a better treatment of this important comorbidity of heart failure patients.

A prospective cohort examination of haematological parameters in relation to cancer death and incidence: the Busselton Health Study

BACKGROUND

Cancer risk is associated with serum iron levels. The aim of this study was to evaluate whether haematological parameters reflect serum iron levels and may also be associated with cancer risk.

METHODS

We studied 1564 men and 1769 women who were enrolled in the Busselton Health Study, Western Australia. Haematological parameters evaluated included haemoglobin (Hb), mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC) and red cell distribution width (RCDW). Statistical analyses included t-tests for quantitative variables, chi-square tests for categorical variables and Cox proportional hazards regression modelling for cancer incidence and death.

RESULTS

There was marginal evidence of an association between MCV (as a continuous variable) and non-skin cancer incidence in women (HR 1.15, 95% CI 1.013, 1.302; p = 0.030) but the hazard ratio was attenuated to non-significance after adjustment for serum ferritin (SF), iron and transferrin saturation (TS) (HR 1.11, 95% CI 0.972, 1.264; p = 0.126). There was strong evidence of an association between MCHC and prostate cancer incidence in men; the estimated hazard ratio for an increase of one SD (0.5) in MCHC was 1.27 (95% CI 1.064, 1.507; p = 0.008). These results remained significant after further adjustment for SF and iron; the estimated hazard ratio for an increase of one SD (0.5) in MCHC was 1.25 (p = 0.014, 95% CI 1.05 to 1.48).

CONCLUSIONS

The MCHC and MCV were associated with cancer incidence in a Western Australian population, although only MCHC remained associated with prostate cancer after adjusting with serum iron and TS (circulating iron) and SF (storage iron). Haematological parameters are thus of limited utility in population profiling for future cancer risk.

Iron deficiency in chronic and acute heart failure: A contemporary review on intertwined conditions

Iron Deficiency (ID) is increasingly recognized as a prevalent comorbid condition in Heart Failure (HF). Despite this, the pathophysiological mechanisms for progressive ID in either chronic or acute HF are still poorly understood. Beyond the traditional factors for iron deficit in the general population, we ought to review the specificities of such paucity in the HF patient, particularly focusing on the interplay between heightened inflammation, overactivity of the sympathetic nervous system and the so-called cardio-renal-anaemia-ID syndrome. Currently, ID constitutes not only an independent prognostic marker but also a novel safe therapeutic target. Particularly, in selected stable HF patients with reduced left ventricular ejection fraction, intravenous (IV) iron improves symptomatic burden and reduces hospitalizations due to worsening HF. On this topic, the main trials of IV iron with either iron sucrose (Toblli et al., FERRIC-HF and IRON-HF) or ferric carboxymaltose (FAIR-HF, CONFIRM-HF and EFFECT-HF) will be summarized and discussed. Finally, we debate the gaps in knowledge of ID in special populations, namely the unreliability of routine plasmatic surrogate markers to assess iron status in acute and advanced HF, the challenging patient with both HF and Chronic Kidney Disease, as well as efficacy and safety concerns in these settings and the potential role of iron correction in cardiac resynchronization therapy candidates.