Body composition and body fat distribution are related to cardiac autonomic control in non-alcoholic fatty liver disease patients

Association of worsening of nonalcoholic fatty liver disease with cardiometabolic function and intestinal bacterial overgrowth: A cross-sectional study

Background & aims

Non-alcoholic fatty liver disease (NAFLD) has been associated with small bowel bacterial overgrowth (SIBO) and cardiometabolic dysfunction. This cross-sectional study aimed to evaluate the cardio-metabolic parameters and SIBO in patients with different degrees of hepatic fibrosis estimated by NAFLD fibrosis score (NFS).

Methods

Subjects (n = 78) were allocated to three groups: Healthy control (n = 30), NAFLD with low risk of advanced fibrosis (NAFLD-LRAF, n = 17) and NAFLD with a high risk of advanced fibrosis (NAFLD-HRAF, n = 31). Anthropometrics, blood pressure, electrocardiogram and heart rate variability (HRV) were evaluated. Only the NAFLD-LRAF and NAFLD-HRAF groups were submitted to blood biochemical analysis and glucose hydrogen breath tests.

Results

The NAFLD-HRAF group had higher age and body mass index when compared to the control and NAFLD-LRAF groups. The prevalence of SIBO in the NAFLD group was 8.33%. The low frequency/high-frequency ratio (LF/HF ratio) was augmented in NAFLD-LRAF (p < 0.05) when compared with control group. NAFLD-HRAF group had a wide QRS complex (p < 0.05) and reduced LF/HF ratio (p < 0.05) compared to the control and NAFLD-LRAF groups. Serum levels of albumin and platelets were more reduced in the NAFLD-HRAF subjects (p < 0.05) than in the NAFLD-LRAF.

Conclusions

NAFLD impairs cardiac autonomic function. Greater impairment was found in subjects with a worse degree of hepatic fibrosis estimated by NFS. Hypoalbuminemia and thrombocytopenia were higher in subjects with a worse degree of hepatic fibrosis, whereas prevalence of SIBO positive was similar between the groups.

The degree of hepatic steatosis associates with impaired cardiac and autonomic function

BACKGROUND & AIMS

Cardiovascular disease is the principle cause of death in patients with elevated liver fat unrelated to alcohol consumption, more so than liver-related morbidity and mortality. The aim of this study was to evaluate the relationship between liver fat and cardiac and autonomic function, as well as to assess how impairment in cardiac and autonomic function is influenced by metabolic risk factors.

METHODS

Cardiovascular and autonomic function were assessed in 96 sedentary individuals: i) non-alcoholic fatty liver disease (NAFLD) (n = 46, hepatic steatosis >5% by magnetic resonance spectroscopy), ii) Hepatic steatosis and alcohol (dual aetiology fatty liver disease [DAFLD]) (n = 16, hepatic steatosis >5%, consuming >20 g/day of alcohol) and iii) CONTROL (n = 34, no cardiac, liver or metabolic disorders, <20 g/day of alcohol).

RESULTS

Patients with NAFLD and DAFLD had significantly impaired cardiac and autonomic function when compared with controls. Diastolic variability and systolic variability (LF/HF-sBP [n/1]; 2.3 (1.7) and 2.3 (1.5) vs. 3.4 (1.5), p <0.01) were impaired in patients with NAFLD and DAFLD when compared to controls, with DAFLD individuals showing a decrease in diastolic variability relative to NAFLD patients. Hepatic steatosis and fasting glucose were negatively correlated with stroke volume index. Fibrosis stage was significantly negatively associated with mean blood pressure (r = -0.47, p = 0.02), diastolic variability (r = -0.58, p ≤0.01) and systolic variability (r = -0.42, p = 0.04). Hepatic steatosis was independently associated with cardiac function (p ≤0.01); TNF-α (p ≤0.05) and CK-18 (p ≤0.05) were independently associated with autonomic function.

CONCLUSION

Cardiac and autonomic impairments appear to be dependent on level of liver fat, metabolic dysfunction, inflammation and fibrosis staging, and to a lesser extent alcohol intake. Interventions should be sought to moderate the excess cardiovascular risk in patients with NAFLD or DAFLD.

LAY SUMMARY

Increased levels of fat in the liver impair the ability of the cardiovascular system to work properly. The amount of fat in the liver, metabolic control, inflammation and alcohol are all linked to the degree that the cardiovascular system is affected.

Association of Lower Cardiovagal Tone and Baroreflex Sensitivity With Higher Liver Fat Content Early in Type 2 Diabetes

CONTEXT

Cardiovascular autonomic neuropathy (CAN) diagnosed by diminished heart rate variability (HRV) is prevalent and carries an increased risk of mortality in patients with diabetes and chronic liver diseases.

OBJECTIVE

To determine whether lower HRV is associated with increased liver fat content in recent-onset diabetes.

DESIGN

Cross-sectional study.

SETTING

German Diabetes Study (GDS), Düsseldorf, Germany.

PARTICIPANTS

Individuals with type 1 diabetes (n = 97) or type 2 diabetes (n = 109) with known diabetes duration ≤1 year and two age- and sex-matched glucose-tolerant control groups from the GDS baseline cohort.

MAIN OUTCOME MEASURES

Four time and frequency domain HRV indices each were measured over 3 hours during a hyperinsulinemic-euglycemic clamp, whereas spontaneous cross-correlation baroreflex sensitivity (xBRS) was computed over 5 minutes. Hepatic fat content was determined by 1H magnetic resonance spectroscopy, and values >5.56% were defined as hepatic steatosis.

RESULTS

Hepatic steatosis was observed in 52% and 5% of patients with type 2 and type 1 diabetes, respectively. After adjustment for sex, age, body mass index, smoking, diabetes duration, hemoglobin A1c, M-value, and triglycerides, all four vagus-mediated time domain HRV indices, three of four frequency domain indices, and xBRS were inversely associated with liver fat content in participants with type 2 diabetes (all P < 0.05) but not in the group with type 1 diabetes.

CONCLUSIONS

Both lower cardiovagal tone and baroreflex sensitivity are strongly associated with prevalent hepatic steatosis in patients with recent-onset type 2 as opposed to type 1 diabetes, suggesting a role for hepatic steatosis in the early development of parasympathetic CAN in type 2 diabetes.

The Role of Nonalcoholic Fatty Liver Disease on Cardiovascular Manifestations and Outcomes

Cardiovascular disease has been postulated as the leading cause of mortality among patients with nonalcoholic fatty liver disease (NAFLD), rather than from sequalae of liver disease specifically. While there is ample evidence validating the association between NAFLD and increased cardiovascular comorbidities, events, and mortality, current data presents a challenge in attributing this effect solely due to NAFLD given the rampant presence of insulin resistance and type 2 diabetes mellitus (T2DM). Endpoints of increased cardiovascular risk remains tightly linked to the concomitant presence of insulin resistance and T2DM. Prospective studies accentuating early detection of NAFLD are imperative to institute early intervention and prevent future cardiovascular events.

Waist-to-height ratio is independently related to whole and central body fat, regardless of the waist circumference measurement protocol, in non-alcoholic fatty liver disease patients

BACKGROUND

Waist-to-height ratio (WHtR) has been reported as a preferable risk related body fat (BF) marker, although no standardised waist circumference measurement protocol (WCmp) has been proposed. The present study aimed to investigate whether the use of a different WCmp affects the strength of relationship between WHtR and both whole and central BF in non-alcoholic fatty liver disease (NAFLD) patients.

METHODS

BF was assessed with dual energy X-ray absorptiometry (DXA) in 28 NAFLD patients [19 males, mean (SD) 51 (13) years and nine females, 47 (13) years]. All subjects also underwent anthropometric evaluation including height and waist circumference (WC) measurement using four different WCmp (WC1, minimal waist; WC2, iliac crest; WC3, mid-distance between iliac crest and lowest rib; WC4, at the umbilicus) and WHtR was calculated using each WC measurements (WHtR1, WHtR2, WHtR3 and WHtR4, respectively). Partial correlations were conducted to assess the relation of WHtR and DXA assessed BF.

RESULTS

All WHtR were particularly correlated with central BF, including abdominal BF (r = 0.80, r = 0.84, r = 0.84 and r = 0.78, respectively, for WHtR1, WHtR2, WHtR3 and WHtR4) and central abdominal BF (r = 0.72, r = 0.77, r = 0.76 and r = 0.71, respectively, for WHtR1, WHtR2, WHtR3 and WHtR4), after controlling for age, sex and body mass index. There were no differences between the correlation coefficients obtained between all studied WHtR and each whole and central BF variable.

CONCLUSIONS

Waist-to-height ratio was found a suitable BF marker in the present sample of NAFLD patients and the strength of the relationship between WHtR and both whole and central BF was not altered by using different WCmp in the present sample of NAFLD patients.

Cardiovascular Disease and Myocardial Abnormalities in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in many developed countries, affecting an estimated 30 % of the adult population. In this updated clinical review, we summarize the current knowledge regarding the strong association between NAFLD and the risk of coronary heart disease (CHD) and other functional, structural, and arrhythmic cardiac complications (e.g., left ventricular dysfunction, heart valve diseases and atrial fibrillation). We also briefly discuss the putative biological mechanisms linking NAFLD with these important extra-hepatic complications. To date, a large body of evidence has suggested that NAFLD is not simply a marker of CHD and other functional, structural, and arrhythmic cardiac complications, but also may play a part in the development and progression of these cardiac complications. The clinical implication of these findings is that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions aimed at decreasing the risk of CHD and other cardiac and arrhythmic complications.

Cardiovascular Autonomic Dysfunction in Patients of Nonalcoholic Fatty Liver Disease

Aim. The present study was designed to evaluate the heart rate variability (HRV) in nonalcoholic fatty liver disease (NAFLD) and to assess the effect of grade of NAFLD and diabetic status on HRV. Methods. This cross-sectional study included 75 subjects (25 NAFLD without diabetes, 25 NAFLD with diabetes, and 25 controls). Measurements included anthropometry, body composition analysis, estimation of plasma glucose, serum lipids, hsCRP, and serum insulin. HRV analysis was performed in both time and frequency domains. Results. The time and frequency domain indices of overall variability (SDNN, total power) were significantly lower in NAFLD with diabetes as compared to the controls. However, the LF : HF ratio did not differ among the three groups. The variables related to obesity, lipid profile, and glucose metabolism were also higher in NAFLD with diabetes and those with Grade II NAFLD without diabetes, as compared to controls. Multivariate stepwise regression analysis showed a negative correlation between HRV and total cholesterol and fat percentage. Conclusion. The grade of NAFLD as well as diabetic status contributes to the decrease in the cardiovascular autonomic function, with diabetic status rather than grade of NAFLD playing a critical role. Serum lipids and adiposity may also contribute to cardiac autonomic dysfunction.