BNT162b2 Booster Dose Elicits a Robust Antibody Response in Subjects with Abdominal Obesity and Previous SARS-CoV-2 Infection

Little is known about the long-term durability of the induced immune response in subjects with obesity, particularly in those with an abdominal distribution of adipose tissue. We evaluated SARS-CoV-2-specific antibody responses after BNT162b2 vaccine booster dose, comparing individuals with and without abdominal obesity (AO), discerning between individuals previously infected or not. IgG-TrimericS were measured in 511 subjects at baseline, on the 21st day after vaccine dose 1, and at 1, 3, 6, and 9 months from dose 2, and at 1 and 3 months following the booster dose. To detect SARS-CoV-2 infection, nucleocapsid antibodies were measured at baseline and at the end of the study. Multivariable linear regression evaluated the three-month difference in the absolute variation in IgG-TrimericS levels from booster dose, showing AO and SARS-CoV-2 infection status interactions (p = 0.016). Regardless of possible confounding factors and IgG-TrimericS levels at the booster dose, AO is associated with a higher absolute change in IgG-TrimericS in prior infected individuals (p = 0.0125). In the same regression model, no interaction is highlighted using BMI (p = 0.418). The robust response in the development of antibodies after booster dose, observed in people with AO and previous infection, may support the recommendations to administer a booster dose in this population group.

Semaglutide therapy decreases epicardial fat inflammation and improves psoriasis severity in patients affected by abdominal obesity and type-2 diabetes

Summary

Psoriasis is often associated with abdominal obesity and type-2 diabetes (T2D). The inflammatory process in psoriasis can target adipose tissue depots, especially those surrounding the heart and coronary arteries, exposing to an increased risk of cardiovascular diseases. A 50-year-old female patient referred to us for abdominal obesity and T2D, which were not controlled with lifestyle modifications. She had suffered from psoriasis for some years and was treated with guselkumab, without success. Epicardial adipose tissue (EAT) attenuation and pericoronary adipose tissue (PCAT) attenuation for each coronary, defined as mean attenuation expressed in Hounsfield unit (HU), were assessed by routine coronary computed tomography angiography. At baseline, EAT attenuation was -80 HU and PCAT attenuation of the right coronary artery (RCA) was -68 HU, values associated with an increased cardiac mortality risk. Psoriasis area and severity index (PASI) was 12.0, indicating severe psoriasis, while dermatology life quality index (DLQI) was 20, indicating a negative effect on the patient's life. Semaglutide (starting with 0.25 mg/week for 4 weeks, increased to 0.50 mg/week for 16 weeks, and then to 1 mg/week) was started. After 10 months, semaglutide treatment normalized glycated hemoglobin and induced weight loss, particularly at abdominal level, also followed by a reduction in computed tomography-measured EAT volume. EAT attenuation and PCAT attenuation of RCA decreased, showing an important reduction of 17.5 and 5.9% respectively, compared with baseline. PASI and DLQI decreased by 98.3 and 95% respectively, indicating an improvement in psoriasis skin lesions and an important amelioration of the patient's quality of life, compared with baseline.

Learning points

Psoriasis patients affected by obesity and type-2 diabetes (T2D) are often resistant to biologic therapies. Psoriasis is often associated with abdominal obesity, T2D, and cardiovascular diseases (CVD), given their shared inflammatory properties and pathogenic similarities. Epicardial adipose tissue (EAT) inflammation can cause the distinctive pattern of CVD seen in psoriasis. EAT and pericoronary adipose tissue (PCAT) attenuation, assessed by routine coronary computed tomography angiography (CCTA), can be used as biomarkers of inflammation and allow monitoring of medical anti-inflammatory therapies. The actions of semaglutide to reduce energy intake, improve glycemic control, and produce effective weight loss, particularly at the visceral fat depot level, can diminish adipose tissue dysfunction, reduce EAT attenuation and PCAT attenuation of the right coronary artery (RCA) and concomitantly ameliorate the clinical severity of psoriasis. Semaglutide therapy may be considered in psoriasis patients affected by T2D and abdominal obesity, despite low cardiovascular risk by traditional risk scores, who are resistant to biologic therapies.

Human Epicardial Adipose Tissue Expresses Glucose-dependent Insulinotropic Polypeptide, Glucagon and Glucagon-Like Peptide 1 Receptors as Potential Targets of Pleiotropic Therapies

BACKGROUND

Human Epicardial Adipose Tissue (EAT) plays a crucial role in the development and progression of coronary artery disease, atrial fibrillation and heart failure. Microscopically, EAT is composed of adipocytes, nerve tissues, inflammatory, stromovascular and immune cells. EAT is a white adipose tissue, albeit it also has brown-fat like or beige fat features. No muscle fascia divides EAT and myocardium; this allows a direct interaction and cross talk between the epicardial fat and the myocardium. Thus, it might be a therapeutic target for pharmaceutical compounds acting on G-Protein-Coupled Receptors, such as those for Glucose-dependent Insulinotropic Polypeptide (GIP), Glucagon (GCG) and Glucagon-Like Peptide-1 (GLP-1), whose selective stimulation with innovative drugs has demonstrated beneficial cardiovascular effects. The precise mechanism of these novel drugs and their tissue and cellular target(s) need to be better understood.

AIM

We evaluate whether human EAT expresses GIP, GCG and GLP-1 receptors and whether their presence is related to EAT transcriptome. We also investigated protein expression and cell type localization specifically for GIPR and GCGR.

METHODS

EAT samples were collected from 33 patients affected by cardiovascular diseases undergoing open heart surgery (90.9% males, age 67.2±10.5 years mean ± SD). Microarray and immunohistochemistry analysis were performed.

RESULTS

Microarray analysis showed that GIPR and GCGR messenger Ribonucleic Acids (mRNAs) are expressed in EAT, beyond confirming the previously found GLP-1(3776±1377 arbitrary unit (A.U.), 17.77±14.91 A.U., and 3.41±2.27 A.U., respectively). The immunohistochemical analysis consistently indicates that GIPR and GCGR are expressed in EAT, mainly in macrophages, isolated and in crown-like structures. In contrast, only some mature adipocytes of different sizes showed cytoplasmic immunostaining, similar to endothelial cells and pericytes in the capillaries and pre-capillary vascular structures. Notably, EAT GIPR is statistically associated with the low expression of genes involved in Free Fatty Acid (FFA) oxidation and transport and those promoting FFA biosynthesis and adipogenesis (p<0.01). EAT GCGR, in turn, is related to genes involved in FFA transport, mitochondrial fatty acid oxidation, and white-to-brown adipocyte differentiation, in addition to genes involved in the reduction of fatty acid biosynthesis and adipogenesis (p<0.01).

CONCLUSIONS

Having reported the expression of the GLP-1 receptor previously, here, we showed that GIPR and GCGR similarly present at mRNA and protein levels in human EAT, particularly in macrophages and partially adipocytes, suggesting these G-protein-coupled receptors as pharmacological targets on the ongoing innovative drugs, which seem cardiometabolically healthy well beyond their effects on glucose and body weight..

The density of crown-like structures in epicardial adipose tissue could play a role in cardiovascular diseases

PURPOSE

The visceral fat of patients affected by abdominal obesity is inflamed, and the main histopathologic feature is the high density of crown-like structures (CLS). Epicardial adipose tissue (EAT) is a visceral fat of paramount importance for its relationships with coronary vessels and myocardium. Its inflammation in patients with abdominal obesity could be of clinical relevance, but histopathological studies on CLS density in EAT are lacking. This study aimed to assess the histopathology of EAT biopsies obtained from patients undergoing open-heart surgery.

METHODS

We collected EAT biopsies from 10 patients undergoing open-heart surgery for elective coronary artery bypass grafting (CABG) (n = 5) or valvular replacement (VR) (n = 5). Biopsies were treated for light microscopy and immunohistochemistry. We quantify the CLS density in each EAT sample.

RESULTS

Despite all patients having abdominal obesity, in EAT samples, no CLS were detected in the VR group; in contrast, CLS were detected in the CABG group (about 17 CLS/10⁴ adipocytes vs. 0.0 CLS/10⁴ adipocytes, CABG vs. VR group, respectively). An impressive density of CLS (100 times that of other patients) was found in one patient (LS) in the CABG group that had a relevant anamnestic aspect: relatively rapid increase of weight gain, especially in abdominal adipose tissue, coincident with myocardial infarction.

CONCLUSIONS

CLS density could be an important predictive tool for cardiovascular diseases. Furthermore, the LS case implies a role for timing in weight gain.

LEVEL OF EVIDENCE

No level of evidence; this is a basic science study.

Antibody responses to BNT162b2 mRNA vaccine: Infection-naïve individuals with abdominal obesity warrant attention

OBJECTIVE

The excess of visceral adipose tissue might hinder and delay immune response. How people with abdominal obesity (AO) will respond to mRNA vaccines against SARS-CoV-2 is yet to be established. SARS-CoV-2-specific antibody responses were evaluated after the first and second dose of the BNT162b2 mRNA vaccine, comparing the response of individuals with AO with the response of those without, and discerning between individuals with or without prior infection.

METHODS

Immunoglobulin G (IgG)-neutralizing antibodies against the Trimeric complex (IgG-TrimericS) were measured at four time points: at baseline, at day 21 after vaccine dose 1, and at 1 and 3 months after dose 2. Nucleocapsid antibodies were assessed to detect prior SARS-CoV-2 infection. Waist circumference was measured to determine AO.

RESULTS

Between the first and third month after vaccine dose 2, the drop in IgG-TrimericS levels was more remarkable in individuals with AO compared with those without AO (2.44-fold [95% CI: 2.22-2.63] vs. 1.82-fold [95% CI: 1.69-1.92], respectively, p < 0.001). Multivariable linear regression confirmed this result after inclusion of assessed confounders (p < 0.001).

CONCLUSIONS

The waning antibody levels in individuals with AO may further support recent recommendations to offer booster vaccines to adults with high-risk medical conditions, including obesity, and particularly to those with a more prevalent AO phenotype.

Abdominal obesity phenotype is associated with COVID-19 chest X-ray severity score better than BMI-based obesity

PURPOSE

Chest X-ray (CXR) severity score and BMI-based obesity are predictive risk factors for COVID-19 hospital admission. However, the relationship between abdominal obesity and CXR severity score has not yet been fully explored.

METHODS

This retrospective cohort study analyzed the association of different adiposity indexes, including waist circumference and body mass index (BMI), with CXR severity score in 215 hospitalized patients with COVID-19.

RESULTS

Patients with abdominal obesity showed significantly higher CXR severity scores and had higher rates of CXR severity scores ≥ 8 compared to those without abdominal obesity (P < 0.001; P = 0.001, respectively). By contrast, patients with normal weight, with overweight and those with BMI-based obesity showed no significant differences in either CXR severity scores or in the rates of CXR severity scores ≥ 8 (P = 0.104; P = 0.271, respectively). Waist circumference and waist-to-height ratio (WHtR) correlated more closely with CXR severity scores than BMI (r = 0.43, P < 0.001; r = 0.41, P < 0.001; r = 0.17, P = 0.012, respectively). The area under the curves (AUCs) for waist circumference and WHtR were significantly higher than that for BMI in identifying a high CXR severity score (≥ 8) (0.68 [0.60-0.75] and 0.67 [0.60-0.74] vs 0.58 [0.51-0.66], P = 0.001). A multivariate analysis indicated abdominal obesity (risk ratio: 1.75, 95% CI: 1.25-2.45, P < 0.001), bronchial asthma (risk ratio: 1.73, 95% CI: 1.07-2.81, P = 0.026) and oxygen saturation at admission (risk ratio: 0.96, 95% CI: 0.94-0.97, P < 0.001) as the only independent factors associated with high CXR severity scores.

CONCLUSION

Abdominal obesity phenotype is associated with a high CXR severity score better than BMI-based obesity in hospitalized patients with COVID-19. Therefore, when visiting the patient in a hospital setting, waist circumference should be measured, and patients with abdominal obesity should be monitored closely. Level of evidence Cross-sectional descriptive study, Level V.

Epicardial fat inflammation response to COVID-19 therapies

OBJECTIVE

Adipose tissue plays a role in the novel coronavirus disease 2019 (COVID-19). Epicardial adipose tissue (EAT), a unique visceral fat, presents with a high degree of inflammation in severe COVID-19. Whether and how adipose tissue may respond to the COVID-19 therapies is unknown.

METHODS

The difference in computed tomography-measured EAT and subcutaneous (SAT) attenuation, defined as mean attenuation expressed in Hounsfield units (HU), was retrospectively analyzed in 72 patients (mean [SD] age was 59.6 [12.4] years, 50 patients [69%] were men) at the hospital admission for COVID-19 and 99 days (interquartile range = 71-129) after discharge.

RESULTS

At the admission, EAT-HU was significantly correlated with blood glucose levels, interleukin 6, troponin T levels, and waist circumference. EAT-HU decreased from -87.21 (16.18) to -100.0 (11) (p < 0.001), whereas SAT-HU did not change (-110.21 [12.1] to -111.11 [27.82]; p = 0.78) after therapy. Changes in EAT-HU (expressed as ∆) significantly correlated with dexamethasone therapy (r = -0.46, p = 0.006) and when dexamethasone was combined with tocilizumab (r = -0.24, p = 0.04).

CONCLUSIONS

Dexamethasone therapy was associated with significant reduction of EAT inflammation in COVID-19 patients, whereas SAT showed no changes. Anti-inflammatory therapies targeting visceral fat may be helpful in COVID-19.

Tri-Ponderal Mass Index vs body Mass Index in discriminating central obesity and hypertension in adolescents with overweight

BACKGROUND AND AIMS

Recently, it has been hypothesized that Tri-Ponderal Mass Index (TMI) may be a valid alternative to Body Mass Index (BMI) when measuring body fat in adolescents. We aimed to verify whether TMI has better accuracy than BMI in discriminating central obesity and hypertension in adolescents with overweight.

METHODS AND RESULTS

This monocentric and retrospective cross-sectional study included 3749 pupils, 1889 males and 1860 females, aged 12-13. BMI (kg/m²) was calculated and expressed as percentiles and as z-scores. TMI (kg/m³) was calculated, and we used pre-defined cut-off previously proposed by Peterson et al.. For central obesity we adopted the Waist-to-Height Ratio (WHtR) discriminatory value of 0.5. Hypertension was defined as blood pressure ≥95th percentile of age- sex-, and height-specific references recommended by NHBPEP Working Group. The discriminant ability of TMI, BMI and BMI z-score, with respect to central obesity and hypertension, was investigated using non-parametric receiver operating characteristic analysis. The overall misclassification rate for central obesity was 8.88% for TMI vs 14.10% for BMI percentiles and vs 14.92% for BMI z-scores (P < 0.001). The overall misclassification rate for hypertension was 7.50% for TMI vs 22.03% for BMI percentiles and vs 25.19% for BMI z-scores (P < 0.001).

CONCLUSION

TMI is a superior body fat index and it could discriminate body fat distribution more accurately than BMI. This supports the use of TMI, in association with WHtR, to characterize adolescents with overweight and high cardio-metabolic risk. Our analysis needs to be extended to other ethnic groups and replicated in a wider age range and in longitudinal studies.