Intrahepatic triglyceride content is independently associated with chronic kidney disease in obese adults: A cross-sectional study

Liver steatosis and fibrosis markers' association with cardiovascular and renal damage in Japanese adults: the TMM BirThree cohort study

INTRODUCTION AND OBJECTIVES

Patients with non-alcoholic fatty liver disease (NAFLD) are at risk for cardiovascular and chronic kidney diseases. Liver steatosis and fibrosis were assessed using the fatty liver index and fibrosis-4 index, respectively. This study aimed to examine the association between these two parameters in patients with atherosclerosis and chronic kidney disease.

MATERIALS AND METHODS

The two parameters were calculated for 11,867 adults who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Intima-media thickness and estimated glomerular filtration rate were also measured. Logistic regression models were used to estimate the odds ratios (OR).

RESULTS

Overall, 4257 (35.9%) and 4733 (39.9%) participants had a higher probability of liver steatosis and fibrosis, respectively. The adjusted OR of higher fatty liver index compared to lower fatty liver index for atherosclerosis and chronic kidney disease were 0.98 (95% confidence interval [CI], 0.77-1.24) and 1.79 (95% CI, 1.19-2.69), and those of higher FIB-4 compared to lower FIB-4 were 1.03 (95% CI, 0.82-1.30) and 0.79 (95% CI, 0.52-1.19) for atherosclerosis and chronic kidney disease, respectively.

CONCLUSIONS

A higher FLI was associated with CKD independent of other risk factors. Further research is required to identify the causal relationship between liver fat accumulation and CKD.

Advanced liver fibrosis measured by transient elastography predicts chronic kidney disease development in individuals with non-alcoholic fatty liver disease

AIMS/HYPOTHESIS

Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are progressive chronic conditions that share important cardiometabolic risk factors and pathogenic mechanisms. We investigated the association between liver fibrosis measured by transient elastography (TE) and the risk of incident CKD in individuals with NAFLD.

METHODS

A total of 5983 participants with NAFLD (defined as controlled attenuation parameter >222 dB/m) but without CKD who underwent TE between March 2012 and August 2018 were selected. The primary outcome was incident CKD, defined as the occurrence of eGFR <60 ml min^-1 [1.73 m]^-2 or proteinuria (≥1+ on dipstick test) on two consecutive measurements during follow-up. The secondary outcome was a 25% decline in eGFR measured on two consecutive visits.

RESULTS

The mean age was 51.8 years and 3756 (62.8%) participants were male. During 17,801 person-years of follow-up (mean follow-up of 3.0 years), 62 participants (1.0%) developed incident CKD. When stratified into TE-defined fibrosis stages (F0-F4), multivariable Cox models revealed that risk of incident CKD was 5.40-fold (95% CI 2.46, 11.84; p < 0.001) higher in the F3/F4 group (≥9.5 kPa) than in the F0 group (<5.5 kPa). During 17,577 person-years of follow-up (mean follow-up of 3.0 years), 201 participants (3.4%) experienced the secondary outcome, for which the F3/F4 group had a 3.22-fold higher risk (95% CI 1.96, 5.28; p < 0.001) than the F0 group.

CONCLUSIONS/INTERPRETATION

In this large cohort of individuals with NAFLD but without baseline CKD, advanced liver fibrosis measured by TE was significantly associated with a higher risk of incident CKD.

Serum creatinine levels and risk of nonalcohol fatty liver disease in a middle-aged and older Chinese population: A cross-sectional analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is now regarded as the hepatic manifestation of metabolic syndrome (MetS). Recent research has suggested that serum creatinine (SCr) may be an indicator of MetS and its related diseases. We aimed to investigate the association between SCr and NAFLD in Chinese adults.

METHODS

A cross-sectional sample of 8862 subjects aged 40 years or older (40-73 years) from China were analysed in this study. The anthropometric measurements, laboratory tests, and hepatic ultrasonography were conducted. NAFLD presence was defined by hepatic ultrasound in the absence of other liver diseases.

RESULTS

NAFLD subjects had higher SCr than those without NAFLD (66.8 μmol/L vs. 65.6 μmol/L, p < 0.001). Moreover, SCr levels were correlated with alanine aminotransferase (β = 0.099, p < 0.001), aspartate aminotransferase (β = 0.135, p < 0.001), γ-glutamyltransferase (β = 0.039, p < 0.001), and insulin resistance (β = 0.027, p = 0.014) after adjusted for potential covariates. In the multivariable-adjusted logistic regression analyses, compared to the first SCr quintile, the odds ratio for NAFLD was 1.35 (95% confidence interval 1.14-1.60, p < 0.001) for the fifth quintile after adjusting multiple measured confounders.

CONCLUSION

SCr concentration is independently associated with NAFLD in a middle aged and older Chinese population. Elevated SCr levels, even within normal ranges, were associated with higher risk of NAFLD.

Circulating adipsin is associated with asymptomatic carotid atherosclerosis in obese adults

Background

Adipsin has been identified as a secreted adipokine that plays a critical pathogenic role in metabolic disorders. However, it is not clear regarding the association of circulating adipsin with cardiovascular disease (CVD). This study will explore the association between circulating adipsin and asymptomatic carotid atherosclerosis in Chinese obese adults.

Methods

A total of 483 obese adult subjects (aged 40 years or older) were enrolled in this study. Serum adipsin concentrations and carotid intima-media thickness (CIMT) were measured to determine these associations.

Results

Individuals with increased CIMT and asymptomatic carotid atherosclerosis had lower levels of circulating adipsin than controls (both p < 0.05). The prevalence of asymptomatic carotid atherosclerosis was significantly higher in subjects with lower levels of serum adipsin than those with higher values (42.5% vs. 36.7%, p < 0.05). Notably, subjects in the lowest quartile of serum adipsin were 1.94 times (p = 0.059) more likely to have increased CIMT and 2.91 times (p = 0.03) more likely to have asymptomatic carotid atherosclerosis than those in the highest quartile in multivariable logistic regression analyses, adjusting for age, gender, current smoking, alcohol consumption, physical activity, BMI, systolic BP, fasting glucose, total cholesterol, HDL-c, and HOMA-IR. However, such associations with circulating adipsin were not noted for atherosclerotic plaque.

Conclusions

These findings suggest that circulating adipsin concentrations are a potential marker of risks of increased CIMT and asymptomatic carotid atherosclerosis in obese Chinese adults.

Extrahepatic Manifestations of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and encompasses a spectrum of pathology from simple steatosis to inflammation and significant fibrosis that leads to cirrhosis. NAFLD and its comorbid conditions extend well beyond the liver. It is a multisystemic clinical disease entity with extrahepatic manifestations such as cardiovascular disease, type 2 diabetes, chronic kidney disease, hypothyroidism, polycystic ovarian syndrome, and psoriasis. Indeed, the most common causes of mortality in subjects with NAFLD are cardiovascular disease, followed by malignancies and then liver-related complications as a distant third. This review focuses on several of the key extrahepatic manifestations of NAFLD and areas for future investigation. Clinicians should learn to screen and initiate treatment for these extrahepatic manifestations in a prompt and timely fashion before they progress to end-organ damage.

Association Between Metabolic Associated Fatty Liver Disease and Chronic Kidney Disease: A Cross-Sectional Study from NHANES 2017-2018

PURPOSE

In 2020, an international expert consensus proposed a novel concept, defined as metabolic associated fatty liver disease (MAFLD). We aimed to investigate the association between MAFLD and chronic kidney disease (CKD).

METHODS

A total of 4869 subjects with demographic data, laboratory tests, and ultrasound transient elastography from National Health and Nutrition Examination Surveys of the United States (NHANES) 2017-2018 were included in the study. Statistical analysis was performed to test the independent association between the demographic data, laboratory tests, and non-invasive liver fibrosis scores in subjects with different subgroups of MAFLD.

RESULTS

A total of 4869 subjects were identified in the NHANES 2017-2018, of which 1032 (21.2%) subjects were diagnosed with CKD. There was a higher prevalence of CKD in MAFLD subjects than in non-MALFD subjects (22.2% vs 19.1, p=0.048). After 1:1 propensity score matching by gender, age and race, we enrolled 1983 subjects with MAFLD diagnosed based on liver ultrasound transient elastography and 1983 PS-matched subjects without MAFLD. MAFLD was not independently associated with CKD after PSM. Further investigation showed that age (OR: 1.05, 95% CI: 1.03~1.05, p<0.001), hypertension (OR: 1.66, 95% CI: 1.38~2.00, p<0.001), DM (OR: 2.21, 95% CI: 1.89~3.11, p<0.001), hyperuricemia (OR: 1.91, 95% CI: 1.55~2.36, p<0.001), ALP (OR: 1.00, 95% CI: 1.00~1.01, p=0.010), and FIB-4 score (OR: 1.23, 95% CI: 1.05~1.01, p=0.011) were independently associated with CKD. In the subgroup analysis, the subgroups of MAFLD complicated with DM, age, hypertension, and hyperuricemia were independently related to the incidence of CKD. In the subgroup of DM without MAFLD, age, hyperuricemia, ALP, and NFS score were independently related to the incidence of CKD. In the subgroup of MAFLD without DM, age, hypertension, hyperuricemia, and ALP were independently related to the incidence of CKD.

CONCLUSION

Based on the NHANES 2017-2018, MAFLD was not independently associated with CKD. Thus, the link between MAFLD and CKD may be mediated by metabolic abnormalities, such as diabetes mellitus and hyperuricemia.

Risk of Kidney Dysfunction IN Nafld

Background:

The timely identification of traditional and non-traditional precursors and risk factors for chronic kidney disease (CKD) (a common systemic disease defined as a decreased kidney function documented by reduced glomerular filtration rate, or markers of kidney damage, or both) is relevant in clinical practice, as CKD increases the risk of end-stage renal disease and other serious comorbidities. A possible relationship between non-alcoholic fatty liver disease (NAFLD) (which is to date the most common chronic disease worldwide) and CKD has recently gained significant attention of researchers.

Methods :

A systematic literature search using appropriate keywords was made in order to identify relevant articles that have investigated the association between NAFLD and CKD.

Results:

Several observational studies and meta-analyses have reported the existence of an independent association between NAFLD and risk of CKD in patients with and without diabetes. However, whilst the association between NAFLD and risk of prevalent CKD is strong across various patient populations, whether NAFLD is independently associated with the development and progression of CKD is still debatable. Moreover, emerging evidence now suggests a potential association between patatin-like phospholipase domain-containing protein-3 (PNPLA3) rs738409 genotype (the most important genetic variant associated to NAFLD) and decreasing kidney function, independent of NAFLD.

Conclusions :

Convincing evidence now indicates that CKD is increased among patients with NAFLD. For this reason, patients with NAFLD should be regularly monitored for renal function and, on the other hand , NAFLD should be considered in all patients with CKD, especially if they are obese or have type 2 diabetes.

NAFLD as a driver of chronic kidney disease

Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are worldwide public health problems, affecting up to 25-30% (NAFLD), and up to 10-15% (CKD) of the general population. Recently, it has also been established that there is a strong association between NAFLD and CKD, regardless of the presence of potential confounding diseases such as obesity, hypertension and type 2 diabetes. Since NAFLD and CKD are both common diseases that often occur alongside other metabolic conditions, such as type 2 diabetes or metabolic syndrome, elucidating the relative impact of NAFLD on the risk of incident CKD presents a substantial challenge for investigators working in this research field. A growing body of epidemiological evidence suggests that NAFLD is an independent risk factor for CKD and recent evidence also suggests that associated factors such as metabolic syndrome, dysbiosis, unhealthy diets, platelet activation and processes associated with ageing could also contribute mechanisms linking NAFLD and CKD. This narrative review provides an overview of the literature on: a) the evidence for an association and causal link between NAFLD and CKD and b) the underlying mechanisms by which NAFLD (and factors strongly linked with NAFLD) may increase the risk of developing CKD.

Endogenic intoxication as a reflection of metabolic disorders in cows and possibilities of its pharmacological correction

The article presents the results of studies of medium mass molecules concentration in the blood serum of cows with different physiological conditions and correction of this state with livazen, which has an antioxidant and lipotropic effect on liver cells. It was determined that the use of livazen contributed to a decrease in cholesterol in the group of pregnant cows by 21.0 % and in the group of fresh cows by 15.9 %, with a decrease in the concentration of average molecular peptides by 4.0-11.8 % depending on the length of exposure.

The Separate Contributions of Visceral Fat and Liver Fat to Chronic Kidney Disease-Related Renal Outcomes

OBJECTIVES

This study aims to investigate the separate contributions of liver fat and visceral fat on microalbuminuria and impaired renal function, and second, to examine whether non-alcoholic fatty liver disease is causally related to microalbuminuria and/or impaired renal function.

METHODS

Associations between visceral adipose tissue (VAT), hepatic triglyceride content (HTGC), and risk of microalbuminuria and renal function were studied cross-sectionally in the Netherlands Epidemiology of Obesity study. Mendelian randomization using GWAS meta-analysis data was performed to estimate the causal effect of non-alcoholic fatty liver disease (PNPLA3, LYPLAL1, NCAN, GCKR) on eGFR (N_max 118,460), microalbuminuria (N_max 54,116), and impaired renal function (N_max 118,147).

RESULTS

In total, 2,023 participants (mean age 55.5 ± 6.0 years, 53% women) were included of which 29% had fatty liver and 2.0% chronic kidney disease stage ≥3. In joint models, VAT was associated with a 2-fold increased risk of microalbuminuria which was mainly driven by the association in women (total population: per standard deviation [SD] = 55.4 cm², odds ratio [OR] 2.02, 95% confidence interval [CI] 1.18-3.47; women: OR 2.83, 95% CI 1.44, 5.56), but HTGC was not (total population: per SD = 7.9%, OR 1.20, 95% CI 0.85, 1.70). No associations were found for VAT and HTGC with eGFR (VAT: per SD = 55.4 cm², OR 1.25, 95% CI 0.83, 1.87; HTGC: per SD = 7.9%, OR 0.65, 95% CI 0.42, 0.99). No causal effect of NAFLD on microalbuminuria or impaired renal function was found.

CONCLUSIONS

In observational analyses, visceral fat was associated with microalbuminuria in women. Liver fat was not associated with microalbuminuria or renal function, which was supported by Mendelian randomization. Visceral fat might be more important than liver fat in the etiology of microalbuminuria.

Nonalcoholic fatty liver disease and eGFR levels could be linked by the PNPLA3 I148M polymorphism in children with obesity

BACKGROUND

PNPLA3 I148M polymorphism has an effect on modulation of estimated glomerular filtration rate (eGFR) in nonobese nondiabetic adults and in children with histologically confirmed nonalcoholic fatty liver disease (NAFLD).

OBJECTIVES

The objective of the study is to explore the impact of PNPLA3 I148M polymorphism on eGFR in children with obesity with and without NAFLD.

METHODS

We genotyped 591 patients with obesity for PNPLA3 I148M polymorphism. Anthropometrical, biochemical, and instrumental data were collected. NAFLD was defined by the presence of ultrasound-detected liver steatosis and/or ALT levels greater than 40 IU/L.

RESULTS

Patients with NAFLD showed significantly lower eGFR levels compared with subjects without NAFLD. Children with PNPLA3 MM genotype showed lower eGFR levels compared with those with either PNPLA3 IM or II genotypes both in the presence and absence of NAFLD. A general linear model for eGFR variance, including gender, duration of obesity, PNPLA3 genotypes, HOMA, BMI-SDS, LDL-C, and triglycerides as covariates, confirmed an inverse association between eGFR and PNPLA3 genotype only in the presence of NAFLD.

CONCLUSIONS

Children with obesity and PNPLA3 MM genotype show lower eGFR levels compared with other genotypes, with a major effect of this polymorphism in the presence of NAFLD.

Development of chronic kidney disease in patients with non-alcoholic fatty liver disease: A cohort study

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) has been associated with chronic kidney disease (CKD), but cohort studies are limited. We investigated the longitudinal association of NAFLD and its severity with the development of CKD.

METHODS

We performed a retrospective cohort study of 41,430 adult men and women (average age, 48.9y) without CKD at baseline who underwent repeated health check-up examinations from January 1, 2003, through December 31, 2013. NAFLD status was assessed by ultrasonography, and NAFLD severity was assessed by the NAFLD fibrosis score (NFS).

RESULTS

The outcome was an incident CKD, defined as an estimated glomerular filtration rate less than 60ml/min/1.73m². During 200,790 person-years of follow-up (median follow-up of 4.15years), we identified 691 incident CKD cases. The multivariable-adjusted hazard ratio for CKD comparing participants with and without NAFLD was 1.22 (95% confidence interval [CI] 1.04-1.43). The risk of CKD increased progressively with increased NAFLD severity. The multivariable-adjusted hazard ratios for CKD comparing participants with NFS <-1.455 and those with NFS ≥-1.455 to participants without NAFLD were 1.09 (95% CI 0.91-1.32) and 1.58 (95% CI 1.30-1.92), respectively. The association was consistent across clinically relevant subgroups.

CONCLUSION

In a large cohort of adult men and women without CKD, NAFLD was associated with an increased risk of CKD development. NAFLD may adversely affect renal function and patients may need to be carefully monitored for an increased risk of CKD.

LAY SUMMARY

The presence of fatty liver is associated with the future decline of renal function. Thus, fatty liver patients need to be monitored regularly for renal function.

Non-alcoholic fatty liver disease and its relationship with cardiovascular disease and other extrahepatic diseases

Key physiological functions of the liver, including glucose and lipid metabolism, become disturbed in the setting of non-alcoholic fatty liver disease (NAFLD) and may be associated with a systemic inflammatory 'milieu' initiated in part by liver-secreted cytokines and molecules. Consequently, the pathophysiological effects of NAFLD extend beyond the liver with a large body of clinical evidence demonstrating NAFLD to be independently associated with both prevalent and incident cardiovascular disease (CVD), chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The magnitude of risk of developing these extrahepatic diseases parallels the underlying severity of NAFLD, such that patients with non-alcoholic steatohepatitis (NASH) appear to be at greater risk of incident CVD, CKD and T2DM than those with simple steatosis. Other modifiers of risk may include genetic variants (eg, patatin-like phospholipase domain-containing 3 and trans-membrane 6 superfamily member 2 polymorphisms), visceral adipose tissue accumulation, dietary intake and the gut microbiome. Emerging data also suggest that NAFLD may be a risk factor for colonic neoplasia and reduced bone mineral density, especially among men. Importantly, improvement/resolution of NAFLD is associated with a reduced incidence of T2DM and improved kidney function, adding weight to causality and suggesting liver focused treatments may reduce risk of extrahepatic complications. Awareness of these associations is important for the clinicians such that CVD risk factor management, screening for T2DM and CKD are part of the routine management of patients with NAFLD.

Glycated Hemoglobin is Independently Associated with Albuminuria in Young Nondiabetic People with Obesity: A Cross-Sectional Study

Background

The aim of this study was to explore the association between glycated hemoglobin (HbA1c) level and albuminuria in young nondiabetic people with obesity.

Material/Methods

A total of 537 young nondiabetic people with obesity were enrolled in this cross-sectional study, which was approved by the Rui-jin Hospital Ethics Committee. Albuminuria was defined as a urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. Multivariate logistic regression was used to analyze the association between HbA1c level and albuminuria.

Results

Urinary ACR progressively increased across the tertiles of HbA1c level (P for trend <0.05). HbA1c levels were positively associated with the risk of albuminuria in the logistic regression analysis after adjustment for confounding factors. The adjusted odds ratio (OR) for albuminuria was 3.72 (95% confidence interval [CI], 1.25–11.00; P=0.017) when comparing between the highest (≥5.7%) and lowest tertiles of HbA1c level (≤5.3%). Moreover, an increment of 1 SD in HbA1c level increased the risk of albuminuria in a fully adjusted model (OR, 1.73; 95% CI, 1.25–2.46).

Conclusions

These data suggest that HbA1c level was independently associated with albuminuria in young nondiabetic people with obesity.

Association between non-invasively diagnosed hepatic steatosis and chronic kidney disease in Chinese adults on their health check-up

OBJECTIVE

To explore the association between chronic kidney disease (CKD), graded by the estimated glomerular filtration rate (eGFR), and non-alcoholic fatty liver disease (NAFLD) using controlled attenuation parameter (CAP) and fatty liver index (FLI) values in Chinese adults undergoing routine health examinations.

METHODS

A total of 731 adult participants without diabetes mellitus or significant alcohol consumption who underwent routine health examinations were included. Their eGFR, CAP, FLI and abdominal ultrasonography results were assessed.

RESULTS

The prevalence of ultrasound-diagnosed NAFLD and CKD (eGFR <60 mL/min per 1.73 m² ) was 36.1% and 6.6%, respectively. CKD was more common in NAFLD patients than in those without (10.6% vs 4.3%, P < 0.001). The CAP and FLI values were significantly higher in the NAFLD group than in those without, but the change in the eGFR was negligible between the two groups. eGFR was negatively correlated with CAP (r = -0.189, P = 0.003) and FLI values (r = -0.130, P = 0.045). Moreover, eGFR was significantly lower in participants with CAP >292 dBm or FLI ≥60 than in those with CAP <238 dBm or FLI <30, respectively (both P < 0.05). The CAP value (odds ratio [OR] 1.099, 95% confidence interval [CI] 1.091-1.108, P = 0.021) was an independent risk factor for CKD.

CONCLUSIONS

A diagnosis of hepatic steatosis is related to an increased risk of CKD among non-alcoholic and non-diabetic Chinese adults regardless of whether the diagnosis was acquired via ultrasound, CAP or FLI. Increased hepatic lipid content may contribute to CKD development.

Non-alcoholic fatty liver disease: an emerging driving force in chronic kidney disease

Non-alcoholic fatty liver disease (NAFLD) is caused by an accumulation of fat in the liver; the condition can progress over time to increase the risk of developing cirrhosis, end-stage liver disease and hepatocellular carcinoma. The prevalence of NAFLD is increasing rapidly owing to the global epidemics of obesity and type 2 diabetes mellitus (T2DM), and NAFLD has been predicted to become the most important indication for liver transplantation over the next decade. It is now increasingly clear that NAFLD not only affects the liver but can also increase the risk of developing extra-hepatic diseases, including T2DM, cardiovascular disease and chronic kidney disease (CKD), which have a considerable impact on health-care resources. Accumulating evidence indicates that NAFLD exacerbates insulin resistance, predisposes to atherogenic dyslipidaemia and releases a variety of proinflammatory factors, prothrombotic factors and profibrogenic molecules that can promote vascular and renal damage. Furthermore, communication or 'crosstalk' between affected organs or tissues in these diseases has the potential to further harm function and worsen patient outcomes, and increasing amounts of evidence point to a strong association between NAFLD and CKD. Whether a causal relationship between NAFLD and CKD exists remains to be definitively established.

Circulating neuregulin 4 levels are inversely associated with subclinical cardiovascular disease in obese adults

Neuregulin 4 (Nrg4) has been identified as a new secreted adipokine that may protect against development of obesity and metabolic disorders. However, information is not available regarding the association between circulating Nrg4 and subclinical atherosclerosis in humans. We measured serum Nrg4 in 485 obese adult subjects (aged 40 years or older) who had the measurement of carotid intima-media thickness (CIMT) recruited from the community. Individuals with increased CIMT and carotid plaque had lower levels of circulating Nrg4 than controls (p < 0.05). The risks of increased CIMT and atherosclerotic plaque were significantly decreased by 28% and 31% [OR (95% CI): 0.72 (0.53–0.98) and 0.69 (0.50–0.96), respectively], adjusting for age, sex, current smoking, alcohol consumption, physical activity, BMI, systolic BP, fasting glucose, total cholesterol, HDL-c, HOMA-IR, and body fat. Importantly, individuals in the lowest quartile of serum Nrg4 were 3.70 times (p < 0.001) more likely to have increased CIMT and 2.06 times (p < 0.05) more likely to have atherosclerotic plaque than those in the highest quartile in multivariable logistic regression analyses. These findings suggest that circulating Nrg4 concentrations are inversely associated with subclinical atherosclerosis in obese adults, and indicating that circulating Nrg4 might play a role in identifying patients at high risk for CVD.

Association of circulating neuregulin 4 with metabolic syndrome in obese adults: a cross-sectional study

BACKGROUND

Neuregulin 4 (Nrg4) is a secreted adipokine recently identified as playing an important role in modulating systemic energy metabolism and the development of obesity-associated disorders. However, information is not available regarding the association between circulating Nrg4 and risk of metabolic syndrome (MetS) in humans.

METHODS

We measured serum Nrg4 in 1212 obese adult subjects (aged 40 years or older), with a waist circumference greater than 90 cm for men or 80 cm for women, recruited from the community.

RESULTS

MetS subjects had lower levels of circulating Nrg4 than healthy controls (P < 0.01). The prevalence of MetS was higher in subjects with lower levels of circulating Nrg4 compared to those with higher values (67.3 % vs. 57.4 %, P < 0.05). Likewise, subjects with low levels of circulating Nrg4 had high prevalence of raised fasting glucose and blood pressure, but there was no association with raised triglycerides and reduced HDL-c. In multivariable logistic regression analyses, increased serum Nrg4 was significantly associated with reduced risk of MetS (OR: 0.603; 95 % CI, 0.439-0.828; P = 0.002), adjusting for age, gender, current smoking, alcohol consumption, physical activity, BMI, systolic blood pressure, fasting glucose, triglyceride, HDL-c, HOMA-IR, and body fat mass; however, such associations with serum Nrg4 were not noted for each component of MetS.

CONCLUSIONS

These findings indicate that circulating Nrg4 concentrations are inversely associated with risk of MetS in obese Chinese adults, suggesting that circulating Nrg4 concentrations may be a protective factor in the development of MetS.

The Impact of Nonalcoholic Fatty Liver Disease on Renal Function in Children with Overweight/Obesity

The association between nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease has attracted interest and attention over recent years. However, no data are available in children. We determined whether children with NAFLD show signs of renal functional alterations, as determined by estimated glomerular filtration rate (eGFR) and urinary albumin excretion. We studied 596 children with overweight/obesity, 268 with NAFLD (hepatic fat fraction ≥5% on magnetic resonance imaging) and 328 without NAFLD, and 130 healthy normal-weight controls. Decreased GFR was defined as eGFR < 90 mL/min/1.73 m². Abnormal albuminuria was defined as urinary excretion of ≥30 mg/24 h of albumin. A greater prevalence of eGFR < 90 mL/min/1.73 m² was observed in patients with NAFLD compared to those without liver involvement and healthy subjects (17.5% vs. 6.7% vs. 0.77%; p < 0.0001). The proportion of children with abnormal albuminuria was also higher in the NAFLD group compared to those without NAFLD, and controls (9.3% vs. 4.0% vs. 0; p < 0.0001). Multivariate logistic regression analysis revealed that NAFLD was associated with decreased eGFR and/or microalbuminuria (odds ratio, 2.54 (confidence interval, 1.16–5.57); p < 0.05) independently of anthropometric and clinical variables. Children with NAFLD are at risk for early renal dysfunction. Recognition of this abnormality in the young may help to prevent the ongoing development of the disease.

Quantification of renal steatosis in type II diabetes mellitus using dixon-based MRI

PURPOSE

To evaluate renal lipid content in subjects with and without type II diabetes mellitus (DM2) using Dixon-based magnetic resonance imaging (MRI).

MATERIALS AND METHODS

This retrospective study was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act. Sixty-nine adults with or without DM2 (n = 29, n = 40) underwent 3T MRI of the abdomen using 3D multiecho Dixon gradient-echo acquisition and proton-density fat fraction (FF) reconstruction. FF values were recorded within segmented regions of interest in the kidneys and liver. The FF measurement error was estimated from the within-subject difference between the right and left kidneys using Bland-Altman analysis. Correlation between renal FF, hepatic FF, and body mass index (BMI) was evaluated. The association between renal FF and DM2 was evaluated by Wilcoxon rank sum test as well as by multivariate regression to correct for potential confounding effects of age, sex, BMI, creatinine, and hepatic FF. P < 0.05 was considered statistically significant.

RESULTS

Per-subject 95% limits of agreement of the renal FF measurement were [-3.26%, +3.22%]. BMI was significantly correlated with renal FF (r = 0.266, P = 0.027) and with liver FF (r = 0.344, P = 0.006). Correlation between renal and hepatic FF did not reach statistical significance (r = 0.215, P = 0.090). Median renal FF (±interquartile range) was 2.18% (±2.52%) in the DM2 cohort, significantly higher than 0.80% (±2.63%) in the non-DM2 cohort (P < 0.001). After correcting for potential confounders, the relationship between DM2 and renal FF remained statistically significant (P = 0.005).

CONCLUSION

Renal lipid content can be measured noninvasively using Dixon-based MRI and may be increased in subjects with DM2 compared to those without DM2. J. Magn. Reson. Imaging 2016;44:1312-1319.

Hepatic fat content is a determinant of metabolic phenotypes and increased carotid intima-media thickness in obese adults

Individuals with metabolically healthy obesity (MHO) are at relatively low risk for the development of metabolic abnormalities and subclinical atherosclerosis. This study aims to examine whether hepatic fat accumulation determines metabolic phenotype of obesity and associated with subclinical atherosclerosis. A total of 485 obese adults (aged 40–65 years) who received magnetic resonance spectroscopy were divided into metabolically abnormally obesity (MAO) and MHO groups according to metabolic status. MHO individuals had lower levels of intrahepatic triglyceride (IHTG) content and carotid intima-media thickness (CIMT) than MAO individuals. In multivariable linear regression analyses, IHTG content was independently associated with metabolic syndrome components and CIMT. Based on receiver operating characteristic curve analysis, the IHTG content displayed a higher area under the curve (AUC) for detecting the MAO phenotype (AUC = 0.70, 95%CI = 0.65–0.75) and increased CIMT (AUC = 0.60, 95%CI = 0.54–0.66) than BMI, waist circumference, and body fat percent. MHO individuals were 1.9 times (p < 0.001) more likely to have metabolic syndrome per 1 SD change in IHTG content in multivariable-adjusted models. Likewise, the risk for high CIMT increased 29% per 1 SD change in IHTG content [OR (95% CI):1.29(1.01–1.64)]. These findings suggest that hepatic fat is a potential predictor of metabolically unhealthy obesity phenotype and subclinical atherosclerosis.