Visceral fat in different locations assessed by ultrasound: Correlation with computed tomography and cut-off values in patients with metabolic syndrome

Perirenal fat thickness is an independent predictor for metabolic syndrome in steatotic liver disease

The objective of our study is to measure perirenal fat thickness using MRI in individuals with steatotic liver disease and investigate the relationship between perirenal fat thickness and metabolic syndrome. This retrospective study included consecutive patients with steatotic liver disease who underwent magnetic resonance imaging-proton density fat fraction from October 2018 to February 2020. Among them, patients with crossed fused kidneys or who underwent nephrectomy were excluded. The metabolic abnormalities were reviewed; presence of hypertension, type 2 diabetes, abdominal circumference, triglyceride, and high-density lipoprotein. Perirenal fat was measured in four directions in both kidneys and the total sum of them was calculated. A total of 250 patients (140 males and 110 females) were included. Perirenal fat thickness showed a moderate correlation with waist circumference, creatinine, and hepatic fat fraction (all p < 0.001). Perirenal fat thickness was significantly higher in patients with metabolic syndrome than in patients without (76.8 mm vs. 65.1 mm, p = 0.004). In multivariable regression analysis, the group with high perirenal fat thickness had as significantly higher odd ratio of 2.71 compared to the low group. The perirenal fat thickness is independently associated with metabolic syndrome in patients with steatotic liver disease.

Unraveling the Connection: Visceral Adipose Tissue and Vitamin D Levels in Obesity

Vitamin D deficiency and insufficiency are widespread on a global scale, with multiple factors playing a role in their development, such as limited exposure to sunlight, inadequate dietary consumption, as well as obesity and abdominal fat accumulation. Abdominal obesity, assessed with waist circumference (WC), is associated with metabolic syndrome and has been linked to low vitamin D levels. This study aimed to investigate the relationship between visceral adipose tissue (VAT) and vitamin D levels, particularly examining the potential threshold for vitamin D storage and sequestration using adipose tissue. The study was conducted between 2020 and 2022 with 58 patients from an internal medicine outpatient department. Patients with certain medical conditions and those taking medications affecting bone metabolism were excluded. Blood samples were collected at baseline and after 6 months of monthly cholecalciferol supplementation. Ultrasonography was used to evaluate adipose tissue measurements, including subcutaneous adipose tissue thickness, VAT, preperitoneal adipose tissue (PPAT), and prerenal adipose tissue (PRAT). Anthropometric measures such as the waist-to-hip ratio and waist-to-height ratio were also assessed. The results showed that all subjects had significant hypovitaminosis D at baseline. After 6 months of supplementation, the mean increase in vitamin D levels was 9.6 ng/mL, with 55.2% of subjects becoming deficient. The study revealed a significant correlation between follow-up vitamin D levels and waist circumference, hip circumference, and VAT. VAT exhibited a strong correlation not only with vitamin D levels but also with waist circumference. When analyzing gender differences, males showed a higher weight and waist-to-hip ratio, while females had higher body adiposity indexes and subcutaneous adipose tissue measurements. In conclusion, this study highlights the relationship between VAT and vitamin D levels, emphasizing the potential role of adipose tissue in vitamin D availability. Waist circumference was identified as a surrogate measure for VAT evaluation. Furthermore, the study showed variations in vitamin D response to supplementation between genders, with a higher percentage of males reaching normal vitamin D levels. Predictive factors for vitamin D levels differed between genders, with waist circumference being a significant predictor in males and body adiposity index in females.

The association between sleep duration and detailed measures of obesity: A cross sectional analysis in the ADDITION-PRO study

Background

Sleep duration is associated with BMI and waist circumference. However, less is known about whether sleep duration affects different measurements of obesity differently.

Objective

To investigate the association between sleep duration and different measures of obesity.

Methods

In this cross-sectional analysis 1309, Danish, older adults (55% men) completed at least 3 days of wearing a combined accelerometer and heart rate-monitor for assessing sleep duration (hours/night) within self-reported usual bedtime. Participants underwent anthropometry and ultrasonography to assess BMI, waist circumference, visceral fat, subcutaneous fat, and fat percentage. Linear regression analyses examined the associations between sleep duration and obesity-related outcomes.

Results

Sleep duration was inversely associated with all obesity-related outcomes, except visceral-/subcutaneous-fat-ratio. After multivariate adjustment the magnitude of associations became stronger and statistically significant for all outcomes except visceral-/subcutaneous-fat-ratio, and subcutaneous fat in women. The associations with BMI and waist circumference demonstrated the strongest associations, when comparing standardized regression coefficients.

Conclusions

Shorter sleep duration were associated with higher obesity across all outcomes except visceral-/subcutaneous-fat-ratio. No specifically salient associations with local or central obesity were observed. Results suggest that poor sleep duration and obesity correlate, however, further research is needed to conclude on beneficial effects of sleep duration regarding health and weight loss.

Perirenal fat thickness and liver fat fraction are independent predictors of MetS in adults with overweight and obesity suspected with NAFLD: a retrospective study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has a multidirectional relationship with metabolic syndrome (MetS) and used to be considered a hepatic manifestation of MetS. Perirenal fat, as a part of visceral adipose tissue (VAT), was reported to be correlated with MetS components, but data for intraorgan fat are lacking. This study was undertaken to assess the value of peripheral and intraorgan fat to predict MetS in adults with overweight and obesity with suspected NAFLD.

METHODS

We studied 134 sequential adults (mean age, 31.5 years; 47% female) with overweight and obesity with suspected NAFLD. All participants underwent abdominal magnetic resonance imaging (MRI) examination. Anthropometric and metabolic parameters and perirenal fat thickness (PRFT), subcutaneous adipose tissue thickness (SATT), liver fat fraction (LFF), pancreas fat fraction (PFF), and lumbar spine fat fraction (LSFF) were collected. MetS was defined according to the International Diabetes Federation (IDF) criteria. Statistical analyses included basic statistics, linear correlation and logistic regression analysis.

RESULTS

A total of 63 adults with MetS and 71 adults with advanced liver steatosis (grades 2 and 3) were included in our study. Patients with MetS had greater PRFT (p = 0.026) and LFF (p < 0.001), as well as greater homeostasis model assessment of insulin resistance (HOMA-IR), alanine transaminase (ALT), aspartate transaminase (AST), and decreased SATT. MetS patients had a higher proportion of advanced steatosis than those without MetS (P < 0.001). The MetS score was associated with PRFT and LFF. Logistic regression analysis showed that the PRFT and LFF were independent predictors of MetS after adjusting for age and sex. A cutoff of 9.15 mm for PRFT and 14.68% for LFF could be predictive of MetS.

CONCLUSIONS

This study shows that the absolute cutoff level of 9.15 mm for PRFT and 14.68% for LFF may be clinically important markers for identifying patients who are at high risk of MetS among adults with overweight and obesity with suspected NAFLD, irrespective of sex and age. Moreover, ectopic fat levels in pancreas and lumbar spine are positively associated with PRFT.

TRIAL REGISTRATION

Not applicable.

Evaluation of ultrasonographic approaches aimed at determining distinct abdominal adipose tissue depots

Objective

To analyze different anatomical sites in the abdominal region, in order to determine the positional parameter that identifies a higher level of visceral adipose tissue (VAT) and confers a greater cardiometabolic risk.

Materials and methods

This is a methodological study in which VAT was evaluated by ultrasonography (USG) in three anatomical sites in the abdomen, while the abdominal circumference (AC) was measured using seven different protocols. Additionally, the glycemic and lipid profile, C-reactive protein, and the presence of systemic arterial hypertension were evaluated.

Results

One hundred and six individuals with an average age of 42 (36.8-46.2) years were included. The evaluation of the calibration of the ultrasound procedure for the analysis of VAT by intra- and inter-evaluators showed high reproducibility. The pattern of abdominal fat distribution differed between sexes, with higher mean VAT in males (p < 0.05) and higher mean SAT (subcutaneous adipose tissue) in females (p < 0.005). In the abdominal scan applied to women, higher levels of VAT and lower levels of SAT were observed in the narrower waist region, between the iliac crest and the last rib (p < 0.001). In males, the profile of adipose disposition along the abdomen was uniform (p > 0.05). Correlations between VAT measured by USG and cardiometabolic parameters were relatively stronger in the upper abdomen (p < 0.05).

Conclusion

Women accumulate more VAT in the narrower waist region, while men accumulate VAT uniformly across the abdomen. There was relative superiority in predicting cardiometabolic risk in the upper abdomen for both sexes.

The perirenal fat thickness was independently associated with serum uric acid level in patients with type 2 diabetes mellitus

BACKGROUND

Obesity is an important risk factor for hyperuricemia. We aimed to explore the relationship between perirenal fat thickness (PrFT) and paranephric fat thickness (PnFT) and serum uric acid (SUA) in patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a cross-sectional study involving 257 patients with T2DM recruited from Beijing Luhe Hospital from September 2019 to May 2020. The basic and clinical information such as age, gender, duration of diabetes was collected through the medical records. All patients underwent a physical examination including height, weight, waist circumference, hip circumference, systolic blood pressures and diastolic blood pressure. The venous blood and urine samples were collected to measure SUA, fasting blood glucose, total cholesterol, triglyceride, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and glycosylated hemoglobin. PrFT and PnFT were measured via ultrasonography. Pearson correlation test and linear regression analysis were used to analyze the association between PrFT and PnFT and SUA.

RESULTS

We found that PrFT and PnFT increased according to the tertiles of SUA level (P = 0.001 and P = 0.009, respectively). In addition, the PrFT and PnFT were positively associated with SUA level (r = 0.25, P < 0.001, r = 0.23, P < 0.001, respectively). Moreover, this association was stronger in males, non-obesity patients and patients with normal renal function. In the multivariate analysis, the PrFT was independently associated with SUA level after adjusting confounding factors.

CONCLUSIONS

The PrFT was independently associated with SUA level in patients with T2DM.