Diagnostic performance of the GGT/HDL-C ratio for NAFLD in adults with obesity undergoing bariatric surgery

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the most frequent liver disease, closely related with metabolic risk factors such as obesity, insulin resistance, dyslipidemia, diabetes mellitus, and metabolic syndrome. In this context, γ-Glutamyl transpeptidase (GGT) and high-density lipoprotein cholesterol (HDL-C) have shown correlations with steatosis severity and metabolic syndrome, respectively. This positions the GGT/HDL-C ratio as a potential diagnostic indicator for NAFLD.

OBJECTIVE

To assess the diagnostic performance of the GGT/HDL-C ratio for NAFLD in adults with obesity undergoing bariatric surgery.

METHODS

We conducted an analytical cross-sectional study, designed as a diagnostic test evaluation. A secondary database of 249 adults with obesity was analyzed. The optimal cut-off point was ascertained using three methodologies, and five adjustment models were constructed for the total population, further stratified by sex.

RESULTS

The optimal cut-off point was 20.5 U/mmol and the AUC of the ratio was 0.81 (95% CI: 0.64-0.98), with sensitivity and specificity being 82.5% and 77.8%, respectively. In the overall group with an elevated GGT/HDL-C ratio, the prevalence of NAFLD increased by 14% (PR: 1.14; 95% CI: 1.04-1.33). Specifically, women displaying this altered ratio showed a 19% increased prevalence (PR: 1.19; 95% CI: 1.07-1.42) compared to those with normal values.

CONCLUSIONS

The GGT/HDL-C ratio is a promising biomarker for the diagnosis of NAFLD in an adult population living with obesity.

Diagnostic Performance of 2D Shear Wave (2D-SWE) for Liver Fibrosis in Adults Undergoing Bariatric Surgery

BACKGROUND

Among the most recent methods to diagnose liver fibrosis is 2D shear wave elastography (2D-SWE). However, the evidence in the Latin population is limited, and there is no consensus on the cutoff points for each stage of fibrosis.

AIM

To evaluate the diagnostic performance of 2D-SWE for liver fibrosis in adults with obesity who underwent bariatric surgery (BS).

METHODS

We conducted a cross-sectional study on patients with obesity who underwent BS between 2020 and 2021. Liver stiffness measurement was reported as the mean of valid measurements in kilopascals made with the 2D-SWE. The outcome was biopsy-proven liver fibrosis. ROC curves were constructed for significant fibrosis (F≥2) and advanced fibrosis (F≥3), with their respective area under the curve (AUC). To obtain the best cutoff point for each scenario, we used the Youden index. The 95% confidence intervals (95% CI) for each cutoff point were estimated by bootstrap with 1000 replications.

RESULTS

We analyzed data from 227 patients. The mean age was 37.8 ± 11.1 years and 65.2% were women. Overall, the AUC for significant and advanced fibrosis was 0.54 (95% CI: 0.47-0.62) and 0.73 (95% CI: 0.60-0.87), respectively. For advanced fibrosis, higher AUCs were found among women (AUC: 0.82; 95% CI: 0.59-1.00) and among patients with morbid obesity (AUC: 0.78; 95% CI: 0.61-0.99).

CONCLUSION

The 2D-SWE appears to be a valuable tool for screening advanced liver fibrosis in candidates for BS, mainly in the female population and in adults with morbid obesity.

Hypertension and Histopathology Severity of Non-Alcoholic Fatty Liver Disease Among Adults with Obesity: A Cross-Sectional Study

Background

Cardiovascular diseases are responsible for the majority of deaths resulting from non-alcoholic fatty liver disease (NAFLD). NAFLD is associated with hypertension and this is a key predictor of severe liver outcomes and an indicator of nonspecific portal fibrosis.

Aim

To assess the association between hypertension and NAFLD severity.

Methods

We conducted a secondary analysis of data from Peruvian adults with obesity and NAFLD who attended a Peruvian bariatric center. The severity of NAFLD was assessed using the Fatty Liver Inhibition of Progression algorithm / Steatosis, Activity and Fibrosis score. Hypertension was determined by either being recorded in the medical records or if the patient had a systolic pressure ≥ 140 mmHg or diastolic pressure ≥ 90 mmHg. To evaluate the association of interest, we calculated crude and adjusted prevalence ratios (aPR) using Poisson generalized linear models with logarithmic link function and robust variances. For the multivariable models, we adjusted for age, sex, physical activity and smoking.

Results

Our study included 234 participants. The prevalence of hypertension was 19.2%, while the prevalence of severe NAFLD was 46.2%. After adjusting for confounders, the prevalence of hypertension was found to be significantly higher in the severe NAFLD group compared to the non-severe group (aPR = 1.33; 95% CI: 1.03-1.74). When stratified by the presence of metabolic syndrome (MetS), the association remained significant only in the group without MetS (aPR = 1.80; 95% CI: 1.05-3.11).

Conclusion

We found an association between hypertension and severe NAFLD in adults with obesity, particularly in those without MetS.

Concordance between Different Criteria for Metabolic Syndrome in Peruvian Adults Undergoing Bariatric Surgery

Background: Metabolic Syndrome (MetS) is a clinical entity that has been linked to several non-communicable diseases. There are various consensuses to determine its presence, such as the IDF, ALAD, Harmonized, AHA/NHLBI, NCEP-ATP III or AACE criteria. However, there is currently no standardization to properly identify it. Objective: To assess the diagnostic concordance between different criteria for MetS in Peruvian adults undergoing bariatric surgery. Methods: We conducted a secondary analysis of the institutional database of a bariatric clinic located in Lima, Peru. We obtained data from adults between 18–59 years who underwent bariatric surgery (Roux-en-Y Gastric Bypass or Sleeve Gastrectomy). According to the Kappa coefficient, a heatplot was designed to analyze the concordance of the criteria. Results: An almost perfect concordance was found between all criteria except AACE. The highest kappa coefficient (κ = 0.980) was recorded between the IDF and ALAD criteria using all the sample. Similar results were obtained when we stratified by sex. Conclusions: This study shows that, excluding the AACE, different criteria for metabolic syndrome could be used in Latino adults undergoing bariatric surgery with similar results. Given the postoperative implications, we believe that IDF and ALAD would be the best options in our population.

Factors Associated with Nutritional Deficiency Biomarkers in Candidates for Bariatric Surgery: A Cross-Sectional Study in a Peruvian High-Resolution Clinic

Previous studies have described multiple nutritional deficiencies after bariatric surgery (BS). However, few studies have evaluated these deficiencies prior to BS, specifically in Latin America. This study aimed to determine the factors associated with nutritional deficiency biomarkers in candidates for BS in Peru. We included adults of both sexes, aged 18 to 59 years, admitted to a Peruvian clinic with a body mass index (BMI) ≥30 kg/m2; they were candidates for BS from 2017 to 2020. We considered the serum levels of hemoglobin and albumin (in tertiles) as the nutritional deficiency biomarkers. In order to assess the associated factors, we calculated crude (cPR) and adjusted prevalence ratios (aPR) with their respective 95% confidence intervals (95%CI). We analyzed 255 patients: 63.1% were males, with a mean age of 37.1 ± 10.3 years and mean hemoglobin and albumin values of 14.0 ± 1.5 g/dL and 4.6 ± 0.4 g/dL, respectively. We found that males (aPR = 1.86; 95%CI: 1.26–2.73; p = 0.002), participants between 30 and 49 (aPR = 2.02; 95%CI: 1.24–3.28; p = 0.004) or 50 years or more (aPR = 2.42; 95%CI: 1.35–4.35; p = 0.003), participants with a BMI ≥40 kg/m2 (aPR = 1.68; 95%CI: 1.09–2.60; p = 0.018), participants with impaired high-density lipoprotein levels (aPR = 1.43; 95%CI: 1.01–2.05; p = 0.049) and individuals in the high tertile of C-reactive protein (aPR = 6.94; 95%CI: 3.37–14.32; p < 0.003) had a higher probability of being in the lower tertile of albumin. In addition, we found that the male sex (aPR = 6.94; 95%CI: 3.37–14.32; p < 0.001) and elevated cholesterol levels (aPR = 0.71; 95%CI: 0.52–0.97; p = 0.034) were associated with the lowest hemoglobin tertile. In our setting, nutritional deficiency biomarkers were associated with sociodemographic, anthropometric and laboratory markers. The pre-bariatric surgery correction of nutritional deficiencies is essential, and can prevent major complications after surgery.

Latin American Research on Bariatric Surgery: a Bibliometric Study

We performed a bibliometric analysis of Latin American documents published between 1984 to 2019 in Scopus-indexed journals. A total of 1856 documents were analyzed. The annual scientific production was 64 documents per year, with an annual increase rate of 15.9%. The countries with the highest scientific production on BS were Brazil (64.7%) and Chile (14.5%). Most of the publications were original (76.6%) and review articles (11.9%). The journal with the highest publication record was "Obesity Surgery" (25.8%). The extra-regional collaboration was mainly with the USA. In conclusion, Latin American scientific production on BS has shown a significant increase in recent years. However, more participation is needed, fostering intra-regional collaboration and involving universities and health institutions in BS research.