Aims To explore variables associated with the serological response following COVID‐19 mRNA vaccine. Methods Eighty‐six healthcare workers adhering to the vaccination campaign against COVID‐19 were enrolled in January–February 2021. All subjects underwent two COVID‐19 mRNA vaccine inoculations (Pfizer/BioNTech) separated by 3 weeks. Blood samples were collected before the 1st and 1–4 weeks after the second inoculation. Clinical history, demographics, and vaccine side effects were recorded. Baseline anthropometric parameters were measured, and body composition was performed through dual‐energy‐X‐ray absorptiometry. Results Higher waist circumference was associated with lower antibody (Ab) titres ( R = −0.324, p = 0.004); smokers had lower levels compared to non‐smokers [1099 (1350) vs. 1921 (1375), p = 0.007], as well as hypertensive versus normotensive [650 ± 1192 vs. 1911 (1364), p = 0.001] and dyslipideamic compared to those with normal serum lipids [534 (972) vs 1872 (1406), p = 0.005]. Multivariate analysis showed that higher waist circumference, smoking, hypertension, and longer time elapsed since second vaccine inoculation were associated with lower Ab titres, independent of BMI, age. and gender. Conclusions Central obesity, hypertension, and smoking are associated with lower Ab titres following COVID‐19 vaccination. Although it is currently impossible to determine whether lower SARS‐CoV‐2 Abs lead to higher likelihood of developing COVID‐19, it is well‐established that neutralizing antibodies correlate with protection against several viruses including SARS‐CoV‐2. Our findings, therefore, call for a vigilant approach, as subjects with central obesity, hypertension, and smoking could benefit from earlier vaccine boosters or different vaccine schedules.

Background Obesity was recently identified as a major risk factor for worse COVID-19 severity, especially among the young. The reason why its impact seems to be less pronounced in the elderly may be due to the concomitant presence of other comorbidities. However, all reports only focus on BMI, an indirect marker of body fat. Aim To explore the impact on COVID-19 severity of abdominal fat as a marker of body composition easily collected in patients undergoing a chest CT scan. Methods Patients included in this retrospective study were consecutively enrolled among those admitted to an Emergency Department in Rome, Italy, who tested positive for SARS-Cov-2 and underwent a chest CT scan in March 2020. Data were extracted from electronic medical records. Results 150 patients were included (64.7% male, mean age 64 ± 16 years). Visceral fat (VAT) was significantly higher in patients requiring intensive care ( p = 0.032), together with age ( p = 0.009), inflammation markers CRP and LDH ( p < 0.0001, p = 0.003, respectively), and interstitial pneumonia severity as assessed by a Lung Severity Score (LSS) ( p < 0.0001). Increasing age, lymphocytes, CRP, LDH, D-Dimer, LSS, total abdominal fat as well as VAT were found to have a significant univariate association with the need of intensive care. A multivariate analysis showed that LSS and VAT were independently associated with the need of intensive care (OR: 1.262; 95%CI: 1.0171–1.488; p = 0.005 and OR: 2.474; 95%CI: 1.017–6.019; p = 0.046, respectively). Conclusions VAT is a marker of worse clinical outcomes in patients with COVID-19. Given the exploratory nature of our study, further investigation is needed to confirm our findings and elucidate the mechanisms underlying such association.

Recent evidence demonstrating an increased fracture risk among obese individuals suggests that adipose tissue may negatively impact bone health, challenging the traditional paradigm of fat mass playing a protective role towards bone health. White adipose tissue, far from being a mere energy depot, is a dynamic tissue actively implicated in metabolic reactions, and in fact secretes several hormones called adipokines and inflammatory factors that may in turn promote bone resorption. More specifically, Visceral Adipose Tissue (VAT) may potentially prove detrimental. It is widely acknowledged that obesity is positively associated to many chronic disorders such as metabolic syndrome, dyslipidemia and type 2 diabetes, conditions that could themselves affect bone health. Although aging is largely known to decrease bone strength, little is yet known on the mechanisms via which obesity and its comorbidities may contribute to such damage. Given the exponentially growing obesity rate in recent years and the increased life expectancy of western countries it appears of utmost importance to timely focus on this topic.

ObjectiveExcess ethanol consumption has serious pathologic consequences. In humans, repeated episodes of binge drinking can lead to liver damage and have adverse effects on other organs such as pancreas and brain. Long term chronic consumption of ethanol can also result in progressive alcoholic liver disease and cirrhosis. Fibroblast growth factor 21 (FGF21) is a metabolic regulator with multiple physiologic functions. FGF21 is a novel biomarker for non-alcoholic fatty liver disease (NAFLD) in humans and limits hepatotoxicity in mice. Therefore, we explored the possibility that FGF21 plays a role in response to ethanol consumption in both humans and mice.MethodsWe used a binge drinking paradigm in humans to examine the effect of acute ethanol consumption on circulating FGF21. We adapted this paradigm to evaluate the acute response to ethanol in mice. We then examined the role of FGF21 on liver pathology in two models of chronic ethanol consumption in both wild type (WT) mice and mice lacking FGF21 (FGF21-KO).ResultsAcute ethanol consumption resulted in a robust induction of serum FGF21 after 6 h in both humans and mice. Serum ethanol peaked at 1 h in both species and was cleared by 6 h. Ethanol clearance was the same in WT and FGF21-KO mice, indicating that FGF21 does not play a major role in ethanol metabolism in a binge paradigm. When FGF21-KO mice were fed the Lieber–DeCarli diet, a high fat diet supplemented with ethanol, a higher mortality was observed compared to WT mice after 16 days on the diet. When FGF21-KO mice consumed 30% ethanol in drinking water, along with a normal chow diet, there was no mortality observed even after 16 weeks, but the FGF21-KO mice had significant liver pathology compared to WT mice.ConclusionsAcute or binge ethanol consumption significantly increases circulating FGF21 levels in both humans and mice. However, FGF21 does not play a role in acute ethanol clearance. In contrast, chronic ethanol consumption in the absence of FGF21 is associated with significant liver pathology alone or in combination with excess mortality, depending on the type of diet consumed with ethanol. This suggests that FGF21 protects against long term ethanol induced hepatic damage and may attenuate progression of alcoholic liver disease. Further study is required to assess the therapeutic potential of FGF21 in the treatment of alcoholic liver disease.

Evidence has lately emerged regarding an increased risk of SARS-CoV-2 with worse prognosis in patients with obesity, especially among the young. Weight excess is a wellestablished respiratory disease risk factor, and the newly reported correlation is therefore unsurprising. The underlying pathophysiology is likely multi-stranded, ranging from complement system hyperactivation, increased Interleukin-6 secretion, chronic inflammation, presence of comorbidities such as diabetes and hypertension, and a possible local, detrimental effect within the lung. Further understanding the link between obesity and SARS-CoV-2 is crucial, as this could aid proper tailoring of immunomodulatory treatments, together with improving stratification among those possibly requiring critical care. Main textThe novel coronavirus disease COVID-19 was identified as the pathogen responsible for an outbreak started in Wuhan, China, in early December 2019, rapidly leading to a major pandemic. The features most commonly associated with acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are male sex, older age, cardiovascular disease, and diabetes. Noteworthy, one study from China reports higher BMI to be more commonly found in non survivors, who had in fact a BMI> 25 kg/m 2 in 88.24% of cases, whereas only 18.95% of the survivors were overweight 1 . On the same line, a recent NHS Intensive Care National Audit & Research Centre (ICNARC) report has shown that 38% of patients admitted to critical care with a diagnosis of SARS-CoV-2 in the UK were obese 2 , higher than its reported prevalence of approximately 30% in British men and women over 50 years old 3 . Moreover, patients with obesity died in critical care in 57.6% of cases, as opposed to approximately 45% of those with a BMI<30 kg/m 2 2 . A French retrospective study showed that 76% of This article is protected by copyright. All rights reserved.

Summary Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease, characterized by hepatic fat accumulation and possible development of inflammation, fibrosis, and cancer. The ketogenic diet (KD), with its drastic carbohydrate reduction, is a now popular weight loss intervention, despite safety concerns on a possible association with fatty liver. However, KDs were also reported to be beneficial on hepatic pathology, with ketone bodies recently proposed as effective modulators of inflammation and fibrosis. If the beneficial impact of weight loss on NAFLD is established, less is known on the effect of macronutrient distribution on such outcome. In a hypocaloric regimen, the latter seems not to be crucial, whereas at higher calorie intake, macronutrient ratio and, theoretically, ketosis, may become important. KDs could positively impact NAFLD for their very low carbohydrate content, and whether ketosis plays an additional role is unknown. Indeed, several mechanisms may directly link ketosis and NAFLD improvement, and elucidating these aspects would pave the way for new therapeutic strategies. We herein aimed at providing an accurate revision of current literature on KDs and NAFLD, focusing on clinical evidence, metabolic pathways involved, and strict categorization of dietary interventions.

Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin K2, is endogenously synthesized by intestinal bacteria and includes several subtypes that differ in side chain length. Aside from its established role in blood clotting, several studies now support a critical function of vitamin K in improving bone health. Vitamin K is in fact required for osteocalcin carboxylation that in turn regulates bone mineral accretion; it seems to promote the transition of osteoblasts to osteocytes and also limits the process of osteoclastogenesis. Several observational and interventional studies have examined the relationship between vitamin K and bone metabolism, but findings are conflicting and unclear. This systematic review aims to investigate the impact of vitamin K (plasma levels, dietary intake, and oral supplementation) on bone health with a particular interest in bone remodeling, mineral density and fragility fractures.

Very low-calorie ketogenic diets (VLCKD) are an effective and increasingly used tool for weight loss. Traditionally considered high protein, ketogenic diets are often looked at with concern by clinicians due to the potential harm they pose to kidney function. We herein evaluated the efficacy and safety of a VLCKD in patients with obesity and mild kidney failure. A prospective observational real-life study was conducted on ninety-two patients following a VLCKD for approximately 3 months. Thirty-eight had mild kidney failure and fifty-four had no renal condition and were therefore designated as control. Anthropometric parameters, bioelectrical impedance and biochemistry data were collected before and at the end of the dietary intervention. The average weight loss was nearly 20% of initial weight, with a significant reduction in fat mass. We report an improvement of metabolic parameters and no clinically relevant variation regarding liver and kidney function. Upon stratification based on kidney function, no differences in the efficacy and safety outcomes were found. Interestingly, 27.7% of patients with mild renal failure reported normalization of glomerular filtrate after dietary intervention. We conclude that, when conducted under the supervision of healthcare professionals, a VLCKD is an effective and safe treatment for weight loss in patients with obesity, including those affected by mild kidney failure.