Fat deposition and partitioning for meat production in cattle and sheep.

In markets for beef and sheep meat, an appropriate level of intramuscular fat (IMF) is highly desirable for meat-eating quality, but strategies to improve it usually lead to an undesirable excess in carcase fat, presenting a major challenge to livestock producers. To solve this problem, we need to understand the partitioning of fat among the major fat depots: IMF, subcutaneous fat (SCF) and visceral fat (VF). In most genotypes of cattle and sheep, the rate of accretion is lower for IMF than for SCF and VF, so genetic selection for a high level of IMF, or the use of an increased dietary energy supply to promote IMF deposition, will increase overall fatness and feed costs. On the other hand, feeding postnatal calves with excessive concentrates promotes IMF deposition, so a nutritional strategy is feasible. With genetic strategies, several problems arise: 1) positive genetic correlations between IMF, SCF and VF differ among genotypes in both cattle and sheep; 2) genotypes appear to have specific, characteristic rates of accretion of IMF during periods of growth and fattening; 3) most breeds of cattle and sheep naturally produce meat with relatively low levels of IMF, but IMF does vary substantially among individuals and breeds so progress is possible through accurate measurement of IMF. Therefore, an essential prerequisite for selection will be knowledge of the genetic correlations and fat accretion rates for each genotype. Currently, selection for IMF is based on existing technology that directly measures IMF in the progeny or siblings, or estimates IMF in live animals. New technology is needed to permit the simultaneous measurement of SCF and IMF in the field, thus opening up the possibility of accurate selection, particularly for fat partitioning in live animals. Specifically, there would be great value in detecting individuals with an IMF advantage at an early age so the generation interval could be shortened and genetic gain accelerated. Genetic gain would also be greatly aided if we could select for genes that control adipogenesis and lipogenesis and are also differentially expressed in the various depots.

Inguinal Fat Compensates Whole Body Metabolic Functionality in Partially Lipodystrophic Mice with Reduced PPARγ Expression.

Peroxisome proliferator-activated receptor γ (PPARγ) gene mutations in humans and mice lead to whole-body insulin resistance and partial lipodystrophy. It is unclear whether preserved fat depots in partial lipodystrophy are beneficial for whole-body metabolic homeostasis. We analyzed the insulin response and expression of metabolic genes in the preserved fat depots of PpargC/- mice, a familial partial lipodystrophy type 3 (FPLD3) mouse model resulting from a 75% decrease in Pparg transcripts. Perigonadal fat of PpargC/- mice in the basal state showed dramatic decreases in adipose tissue mass and insulin sensitivity, whereas inguinal fat showed compensatory increases. Preservation of inguinal fat metabolic ability and flexibility was reflected by the normal expression of metabolic genes in the basal or fasting/refeeding states. The high nutrient load further increased insulin sensitivity in inguinal fat, but the expression of metabolic genes became dysregulated. Inguinal fat removal resulted in further impairment of whole-body insulin sensitivity in PpargC/- mice. Conversely, the compensatory increase in insulin sensitivity of the inguinal fat in PpargC/- mice diminished as activation of PPARγ by its agonists restored insulin sensitivity and metabolic ability of perigonadal fat. Together, we demonstrated that inguinal fat of PpargC/- mice plays a compensatory role in combating perigonadal fat abnormalities.

From an Apple to a Pear: Moving Fat around for Reversing Insulin Resistance.

Type 2 diabetes (T2D) is a chronic condition where the body is resistant to insulin, leading to an elevated blood glucose state. Obesity is a main factor leading to T2D. Many clinical studies, however, have described a proportion of obese individuals who express a metabolically healthy profile, whereas some lean individuals could develop metabolic disorders. To study obesity as a risk factor, body fat distribution needs to be considered rather than crude body weight. Different individuals' bodies favor storing fat in different depots; some tend to accumulate more fat in the visceral depot, while others tend to store it in the femoral depot. This tendency relies on different factors, including genetic background and lifestyle. Consuming some types of medications can cause a shift in this tendency, leading to fat redistribution. Fat distribution plays an important role in the progression of risk of insulin resistance (IR). Apple-shaped individuals with enhanced abdominal obesity have a higher risk of IR compared to BMI-matched pear-shaped individuals, who store their fat in the gluteal-femoral depots. This is related to the different adipose tissue physiology between these two depots. In this review, we will summarize the recent evidence highlighting the underlying protective mechanisms in gluteal-femoral subcutaneous adipose tissues compared to those associated with abdominal adipose tissue, and we will revise the recent evidence showing antidiabetic drugs that impact fat distribution as they manage the T2D condition.

Unified Anatomical Explanation of Diagonal Earlobe Creases, Preauricular Creases, and Paired Creases of the Helix.

Three types of ear creases have been described in the medical literature in association with several cardiovascular and metabolic disorders: diagonal earlobe creases (DELCs) (Frank's sign), preauricular vertical creases, and paired ear creases of the helix (PECH). The exact mechanism of development of such creases, as well as an explanation of their association with cardiometabolic disorders, remains unclear. Herein, the author provides a suggested unified mechanism of development of all three types of auricular creases. In addition, an anatomical explanation linking the associated cardiometabolic disorders and the three types of ear creases to the common culprit of facial visceral adiposity will be given.

Ectopic Fat and Cardiac Health in People with HIV: Serious as a Heart Attack.

PURPOSE OF REVIEW: This study aims to summarize knowledge of alterations in adipose tissue distribution among people with HIV (PWH), with a focus on the cardiac depot and how this relates to the known higher risk of cardiovascular disease in this unique population. RECENT FINDINGS: Similar to the general population, cardiac fat depots mirror visceral adipose tissue in PWH. However, altered fat distribution, altered fat quality, and higher prevalence of enlarged epicardial adipose tissue depots are associated with increased coronary artery disease among PWH. Adipose tissue disturbances present in PWH ultimately contribute to increased risk of cardiovascular disease beyond traditional risk factors. Future research should aim to understand how regulating adipose tissue quantity and quality can modify cardiovascular risk.

Bitemporal Obesity: An Overlooked Sign of Visceral Obesity?

With increasing rates of morbidity and mortality associated with visceral obesity, as well as its related cardiometabolic disorders, physical findings that aid in diagnosing patients at risk for such conditions are extremely useful. This brief report introduces the novel facial physical sign of bitemporal obesity, which the author observed in a patient and suggests to be associated with visceral obesity.

Effect of using a flax seed enriched concentrate on the fatty acid composition of omental fat in Pramenka lambs reared indoors.

This study was intended to determine the effect of adding flax seeds to a concentrate for lamb fattening on the fatty acid composition of the omental fat depot in Pramenka lambs reared indoors. A total of 63 lambs (10±3 kg of live body weight, 30±7 days of age, 30 males and 33 females) were used. They were divided into two groups: a control (CON) fed on hay, ewe's milk, and a 300-g daily ration of a commercial concentrate, and an experimental group (FS) fed on hay, ewe's milk and 300 g/day of the concentrate enriched with 5% of flax seeds. After a 60-day fattening period for each group, 10 lambs (5 males and 5 females) were selected and omental fat samples were analysed for fatty acid composition. Highly significant differences (p⟨0.001) were found between CON and FS in α-linolenic acid, the sum of n-3 fatty acids, and the ratio n-6/n-3 fatty acids. The effect of sex on the fatty acid content in the fat depot was only significant for C20:0 fatty acid (p⟨0.05).

Neck Circumference and Risk of Incident Atrial Fibrillation in the Framingham Heart Study.

Background Increased neck circumference, a proxy for upper-body subcutaneous fat, is associated with cardiovascular risk and metabolic risk factors, accounting for body mass index (BMI) and waist circumference. The association between neck circumference and incident atrial fibrillation (AF) is unclear. The aim of current study was to evaluate the association between neck circumference and incident AF. Methods and Results We selected participants from the Framingham Heart Study aged ≥55 years without diagnosed AF and with available neck circumference, BMI, and waist circumference measurements. We defined high neck circumference as ≥14 inches in women and ≥17 inches in men on the basis of the Contal and O'Quigley changepoint method. We used Fine-Gray models to estimate subdistribution hazards ratios (sHRs) for the association between neck circumference and incident AF accounting for the competing risk of death. We adjusted models for clinical risk factors. We then additionally adjusted separately for BMI, waist circumference, and height/weight. The study sample included 4093 participants (mean age 64±7 years, 55% female). During 11.2±5.7 mean years of follow-up, incident AF occurred in 571 participants. High neck circumference was associated with incident AF (sHR for high versus low: 1.58; 95% CI, 1.32-1.90, P<0.0001). The association remained significant after adjustment for BMI (sHR, 1.51; 95% CI, 1.21-1.89; P=0.0003), waist circumference (sHR, 1.47; 95% CI, 1.18-1.83; P<0.0001), and height/weight (sHR, 1.37; 95% CI, 1.09-1.72; P=0.007). Conclusions High neck circumference was associated with incident AF adjusting for traditional adiposity measures such as BMI and waist circumference.

Modulation of the dynamics and cellularity of adipose tissues in different fat depots in broilers by dietary dexamethasone.

Objective: The objective of this investigation was to determine the effects of dexamethasone (DEX) on the weight and cellularity of abdominal and subcutaneous fat depots. Materials and Methods: The study was conducted on four broiler chicks (20 chicks per group) fed commercial feed and water ad libitum. The DEX was supplied with feed at 0 mg/kg (non-DEX), 3 mg/kg (DEX-1), 5 mg/kg (DEX-2), and 7 mg/kg (DEX-3) from day 0 to day 28. The entire abdominal and subcutaneous fat depots were collected and weighed after sacrificing five birds from each group on days 14 and 28. Results: The DEX groups had considerably lower (p < 0.05) fat depot weights with dose-related variation noted among the DEX groups. The histological findings revealed the presence of unilocular, round to oval-shaped adipocytes. The DEX-1 and DEX-2 had way lower (p < 0.05) numbers of adipocytes while the DEX-3 had considerably higher (p < 0.05) numbers of adipocytes than the non-DEX. DEX-1 and DEX-2 had larger (p < 0.05) adipocytes whereas DEX-3 had smaller adipocytes than the non-DEX. Adipocyte sizes and fat depot weights were found to have very strong negative relationships. Conclusion: Dietary DEX affects the growth and distribution of abdominal and subcutaneous fat depots and adipocyte cellularity subjected to both dose and duration of DEX treatment.

Fattening of Polish Holstein-Friesian × Limousin Bulls under Two Production Systems and Its Effect on the Fatty Acid Profiles of Different Fat Depots.

This study was designed to compare the fatty acid (FA) profiles of four types of fat depots from crossbred bulls (Polish Holstein-Friesian × Limousin, PHF × LM) fattened semi-intensively (SI) and intensively (I). Intramuscular fat was most abundant in total polyunsaturated fatty acids (PUFAs), n-3 and n-6 PUFAs, and functional fatty acids C 18:2, C 18:3, C 20:4 and C 20:5 in comparison with the remaining fat types. Furthermore, note that external fat was more abundant in conjugated linoleic acid (CLA) than other fat types. Grass silage fed to cattle during fattening had a beneficial influence on the FA profile of beef, and an increase in the amount of concentrate in the ration did not decrease beef quality.

Exercise induces favorable metabolic changes in white adipose tissue preventing high-fat diet obesity.

Diet and/or exercise are cost effective interventions to treat obesity. However, it is unclear if the type of exercise undertaken can prevent the onset of obesity and if it can act through different effects on fat depots. In this study we did not allow obesity to develop so we commenced the high-fat diet (HFD) and exercise programs concurrently and investigated the effect of endurance exercise (END) and high-intensity interval training (HIIT) on changes in cellular adipogenesis, thermogenesis, fibrosis, and inflammatory markers in three different fat depots, on a HFD and a chow diet. This was to assess the effectiveness of exercise to prevent the onset of obesity-induced changes. Mice fed with chow or HFD (45% kcal fat) were trained and performed either END or HIIT for 10 weeks (3 x 40 min sessions/week). In HFD mice, both exercise programs significantly prevented the increase in body weight (END: 17%, HIIT: 20%), total body fat mass (END: 46%, HIIT: 50%), increased lean mass as a proportion of body weight (Lean mass/BW) by 14%, and improved insulin sensitivity by 22%. Further evidence of the preventative effect of exercise was seen significantly decreased markers for adipogenesis, inflammation, and extracellular matrix accumulation in both subcutaneous adipose tissue (SAT) and epididymal adipose tissue (EPI). In chow, no such marked effects were seen with both the exercise programs on all the three fat depots. This study establishes the beneficial effect of both HIIT and END exercise in preventing metabolic deterioration, collagen deposition, and inflammatory responses in fat depots, resulting in an improved whole body insulin resistance in HFD mice.

Frank's Sign in Polycystic Ovary Syndrome and Sideburn Adiposity: A Case Report and Illustrated Hypothesis.

The diagnosis of polycystic ovary syndrome (PCOS) remains uniquely dependent on physical examination signs. Diagonal earlobe crease (DELC) also referred to as "Frank's sign, has been associated with several cardiometabolic disorders with further investigations reporting that its occurrence was more prevalent among aging men and thought to a sign of aging skin. However, there is no clear mechanism of development or rationale behind such associations. The author is reporting a novel association between Frank's sign and PCOS in a 23-year-old female patient. The presence of the DELC in young women could alert clinicians to the need to further investigate a diagnosis of PCOS. The author is providing an accompanying hypothesis to suggest possible common pathogenesis that links the two to visceral adiposity of the face.

Fatty acid profile as affected by fat depot and the sex category of Polish Holstein-Friesian × Limousin fattening cattle fed silage ad libitum.

This study was designed to compare the fatty acid profiles of four types of fat depots from bulls, steers, and heifers. All animals were Polish Holstein-Friesian and Limousin crossbreds fattened semi-intensively-silage at libitum and concentrate in the amount corresponding to 30% of their net energy requirements. The fatty acid profile in intramuscular, intermuscular, and external and internal fat was determined. The intramuscular fat of bulls was most abundant in total PUFAs and n-6 PUFAs, and functional fatty acids C 18:2, C 20:4, and C 22:5 in comparison with steers and heifers. Regardless of sex category, intramuscular and external fat were characterized by higher levels of UFAs and a more desirable MUFA/SFA ratio than the remaining fat types. It should also be noted that external fat was more abundant in CLA than other fat types, and that the highest CLA content was found in bull fat, compared with the remaining sex categories of cattle.

Fat Distribution in Women Is Associated With Depot-Specific Transcriptomic Signatures and Chromatin Structure.

BACKGROUND: Preferential accumulation of fat in the upper body (apple shape) is associated with higher risk of developing metabolic syndrome relative to lower body fat (pear shape). We previously discovered that chromatin openness partially defined the transcriptome of preadipocytes isolated from abdominal and gluteofemoral fat. However, the molecular mechanisms underlying interindividual variation in body shape are unknown. METHODS: Adipocyte fraction was isolated from abdominal and gluteofemoral fat biopsies of premenopausal women (age and body mass index matched) segregated initially only by their waist-to-hip ratio. We evaluated transcriptomic and chromatin accessibility using RNA sequencing and assay for transposase-accessible chromatin using sequencing (ATAC-seq) along with key clinical parameters. RESULTS: Our data showed that higher lower body fat mass was associated with better lipid profile and free fatty acid decrease after glucose administration. Lipid and glucose metabolic pathways genes were expressed at higher levels in gluteofemoral adipocyte fraction in pears, whereas genes associated with inflammation were higher both in abdominal and gluteofemoral apple adipocyte fraction. Gluteofemoral adipocyte chromatin from pear-shaped women contained a significantly higher number of differentially open ATAC-seq peaks relative to chromatin from the apple-shaped gluteofemoral adipocytes. In contrast, abdominal adipocyte chromatin openness showed few differences between apple- and pear-shaped women. We revealed a correlation between gene transcription and open chromatin at the proximity of the transcriptional start site of some of the differentially expressed genes. CONCLUSIONS: Integration of data from all 3 approaches suggests that chromatin openness partially governs the transcriptome of gluteofemoral adipocytes and may be involved in the early metabolic syndrome predisposition associated with body shape.

Effect of PPARγ agonist on aerobic exercise capacity in relation to body fat distribution in men with type 2 diabetes mellitus and coronary artery disease: a 1-yr randomized study.

Targeting metabolic determinants of exercise performance with pharmacological agents that would mimic/potentiate the effects of exercise represents an attractive clinical alternative to counterbalance the poor exercise capacity in patients with type 2 diabetes mellitus (T2DM). We examined the effect of 1-yr treatment with the insulin sensitizer peroxisome proliferator-activated receptor (PPAR)γ agonist rosiglitazone on aerobic exercise capacity and body fat composition/distribution in men with T2DM and stable coronary artery disease (CAD). One-hundred four men (age: 64 ± 7 yr; body mass index: 30.0 ± 4.4 kg/m2) with T2DM and CAD were randomized to receive rosiglitazone or placebo for 1 yr. Aerobic exercise capacity (exercise duration) was assessed with a maximal treadmill test, and body composition/distribution were assessed by dual-energy X-ray absorptiometry/computed tomography scans. At 1 yr, patients with T2DM under PPARγ agonist treatment showed a reduction in aerobic exercise capacity compared with the control group (exercise duration change, -31 ± 8 versus 7 ± 11 s, P = 0.009). Significant increases in body fat mass (3.1 ± 0.4 kg, 12%), abdominal and mid-thigh subcutaneous adipose tissue (AT) levels, and mid-thigh skeletal muscle fat were found (all P < 0.01), whereas no effect on visceral AT levels was observed (P > 0.05) under treatment. Subcutaneous fat mass gained under PPARγ agonist was the strongest predictor of the worsening in aerobic exercise capacity (P > 0.0001); no association was found with skeletal muscle fat infiltration nor visceral AT. Treatment with the insulin sensitizer PPARγ agonist rosiglitazone in patients with T2DM and CAD is associated with a worsening in aerobic exercise capacity, which seems to be mainly attributable to weight gain and subcutaneous fat mass expansion.

Benefits of 1-Year Lifestyle Modification Program on Exercise Capacity and Diastolic Function Among Coronary Artery Disease Men With and Without Type 2 Diabetes.

BACKGROUND: To assess the benefits of a 1-year lifestyle modification program on exercise capacity and diastolic function in men with left ventricular (LV) diastolic dysfunction (LVDD) and coronary artery disease (CAD), according to glucose tolerance status. METHODS: Fifty-three men (62 ± 8 years; BMI: 27.3 ± 3.5 kg/m2) with LVDD and CAD were enrolled in a 1-year lifestyle modification program based on dietary management and increased physical activity. Patients were classified by using a 75 grams oral glucose tolerance test as having normal glucose tolerance (n = 16), prediabetes (n = 23), or type 2 diabetes mellitus (T2DM) (n = 14). Cardiac morphology and function, visceral fat, and cardiac fat depots were measured using magnetic resonance imaging, whereas exercise capacity [cardiorespiratory fitness (CRF)] (VO2peak) was assessed with a maximal treadmill test. RESULTS: The 1-year lifestyle modification program was associated with reductions in body weight, and visceral and cardiac fat levels (all P < 0.05). CRF increased by 13% (24.9 ± 4.1 vs. 28.2 ± 4.8 mL O2/kg/min, P < 0.0001). Moreover, half of patients (53%) improved LV diastolic function in response to the lifestyle intervention. Multiple regression analyses revealed that age (partial R2 = 26.9, P < 0.0001) and presence of T2DM (partial R2 = 5.9, P = 0.04) were the stronger predictors of change in diastolic function, while favorable change in LV remodeling index was the best predictor of improvement in LV diastolic function after the lifestyle intervention (R2 = 21.9, P = 0.002). CONCLUSIONS: Irrespective of glucose tolerance status, a 1-year lifestyle modification program in men with LVDD and CAD is associated with significant improvements in exercise capacity and LV diastolic function in more than half of patients.

The role of adipocyte-specific IL-6-type cytokine signaling in FFA and leptin release.

High secretion of interleukin (IL)-6 from white adipose tissue may contribute to metabolic complications in obesity. We have recently shown that IL-6-type cytokine signaling in adipocytes is involved in the development of obesity-associated hepatic insulin resistance and steatosis. In addition, we revealed that adipocyte-specific IL-6 signaling ameliorates glucose metabolism in obesity via enhancing insulin secretion. Mechanistically, IL-6 induces the release of free fatty acid (FFA) and leptin from adipocytes thereby affecting liver metabolism and pancreatic ß-cell function, respectively. This commentary further discusses the role of adipocyte-specific IL-6-type cytokine signaling in the regulation of FFA and leptin release. In particular, we outline depot-specific differences in IL-6-induced basal release of the two aforementioned factors. Moreover, we provide evidence that insulin's effect on the release of FFA and leptin is adipose depot-dependent. We conclude that adipose depot-specific targeting of the IL-6 signaling pathway may be a novel approach to blunt obesity-associated metabolic complications.

Melatonin and Vitamin D Interfere with the Adipogenic Fate of Adipose-Derived Stem Cells.

Adipose-derived stem cells (ADSCs) represent one of the cellular populations resident in adipose tissue. They can be recruited under certain stimuli and committed to become preadipocytes, and then mature adipocytes. Controlling stem cell differentiation towards the adipogenic phenotype could have a great impact on future drug development aimed at counteracting fat depots. Stem cell commitment can be influenced by different molecules, such as melatonin, which we have previously shown to be an osteogenic inducer. Here, we aimed at evaluating the effects elicited by melatonin, even in the presence of vitamin D, on ADSC adipogenesis assessed in a specific medium. The transcription of specific adipogenesis orchestrating genes, such as aP2, peroxisome proliferator-activated receptor γ (PPAR-γ), and that of adipocyte-specific genes, including lipoprotein lipase (LPL) and acyl-CoA thioesterase 2 (ACOT2), was significantly inhibited in cells that had been treated in the presence of melatonin and vitamin D, alone or in combination. Protein content and lipid accumulation confirmed a reduction in adipogenesis in ADSCs that had been grown in adipogenic conditions, but in the presence of melatonin and/or vitamin D. Our findings indicate the role of melatonin and vitamin D in deciding stem cell fate, and disclose novel therapeutic approaches against fat depots.

Influence of conjugated linoleic acid and vitamin E on performance, energy metabolism, and change of fat depot mass in transitional dairy cows.

The objective of this experiment was to determine the effects of conjugated linoleic acid (CLA) and vitamin E as well as their interaction on performance variables and lipomobilization during late pregnancy and early lactation (wk 6 antepartum until wk 10 postpartum). For this purpose, 59 pluriparous German Holstein cows were assigned to 4 dietary groups in a 2 × 2 design with the factors CLA and vitamin E at 2 levels. For this trial, we selected cows with a high body condition score because they are more likely to mobilize fat and consequently are at a higher risk of developing ketosis. Furthermore, concentrate proportions were adjusted to provoke ketosis. Lactation performance variables were analyzed in 3 periods (d 42 antepartum until calving, 1 to 21 d in milk, 22 to 70 d in milk). Dry matter intake and net energy intake were reduced in animals receiving CLA. Milk fat content was reduced in the CLA group compared with the control group (4.83 vs. 5.46% in period 2; 3.36 vs. 4.57% in period 3). In the vitamin E and the CLA + vitamin E groups, reduction of milk fat content was observed in period 3 (3.76 vs. 4.57% compared with the control group). Milk yield was not affected by treatment. ß-Hydroxybutyrate concentrations and liver lipid contents were not influenced by CLA or vitamin E. Moreover, longitudinal changes of adipose tissue depot mass were not affected by dietary treatments. Results suggest that the effects CLA had on milk composition were compensated by an increased milk yield and a decreased dry matter intake. Reduced milk energy output in CLA-treated animals was compensated by a reduced dry matter intake. Therefore, the net energy balance was not affected by either treatment. Consequently, we found no group effect on the mobilization of adipose tissue.

Is epicardial fat depot associated with atrial fibrillation? A systematic review and meta-analysis.

Aims: Atrial fibrillation (AF) is the leading rhythm disorder in western countries. A direct relationship between left atrium (LA) enlargement and electromechanical remodelling has been established. A causative link between epicardial fat (EF), visceral adipose tissue deposited around the heart, and AF has been hypothesized. Several reports suggested the association between EF and the presence of AF. The aim of this study was to verify the relationship between AF and EF depot, performing a meta-analysis of observational case series studies. Methods and results: Studies were identified by searching electronic databases by two independent investigators using 'atrial fibrillation' and 'epicardial fat' as keywords. Comparisons between healthy participants and AF cases were performed using a random effect meta-analysis estimating standardized mean difference among comparison groups. Meta regression was used to address the effect given by potential biological and technical confounders. Through a search result of 502 articles, only 7 were selected to conduct the present study. The comparison between all AF with respect to healthy participants resulted in a 32.0 ml of EF difference (95% confidence interval (CI) = 21.5, 42.5) showing that EF volume is higher in AF cases. A statistical significant difference of EF was observed when comparing both persistent and paroxysmal AF subtypes with respect to healthy participants (EF difference 48.0 ml (95% CI = 25.2, 70.8) and 15.7 ml (95% CI = 10.1, 21.4) for persistent and paroxysmal, respectively). A significant EF difference resulted also when comparing persistent to paroxysmal AF subtypes (29.6 ml (95% CI = 12.7, 46.5)). Conclusions: The present work expands the strength of previously reported association between EF amount and atrial arrhythmia.