United States: A recent scholarly exploration in Annals of Hepatology scrutinized the intricate relationship between the intake of soft drinks (SD) and the predisposition to nonalcoholic fatty liver disease (NAFLD) within a Mexican cohort, predominantly employees of the Mexican Social Security Institute (IMSS) and their family members.
Overview
NAFLD stands as the most common hepatic disorder globally, affecting 20-30% of individuals worldwide. The preponderance of this condition is closely tied to obesity and metabolic dysregulation. Within Mexico, the evaluation of elevated hepatic enzymes—such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT)—serves as a critical marker for assessing NAFLD susceptibility, according to the reports by news-medical.net.
This affliction encompasses a range of liver conditions, extending from benign hepatic steatosis to more severe forms, such as nonalcoholic steatohepatitis (NASH), characterized by hepatic inflammation and fibrosis. NASH can further deteriorate into life-threatening conditions. Recently, the terminology surrounding liver diseases has evolved, now referencing Metabolic Associated Steatotic Liver Disease (MASLD)—which underscores the metabolic components while excluding significant alcohol consumption and secondary causes of hepatic fat accumulation.
Soft drinks laden with added sugars represent a substantial factor in NAFLD progression. However, more focused inquiry is necessary to untangle the causality, particularly across diverse demographics with variegated lifestyles and risk profiles.
Research
The Health Workers Cohort Study (HWCS), initiated in 2004-2006, included IMSS personnel and their relatives. Participants eligible for this analysis were adults aged 20 or older, with ALT/AST levels and a daily energy intake ranging between 500-6500 kcal. The follow-up period (2010-2012) captured 1,627 responses, and an additional 186 participants were incorporated. By 2016-2018, 1,012 individuals attended follow-up, with 1,412 participants retained for final analysis based on sufficient data across at least two waves.
ALT and AST enzyme levels were obtained after fasting for 8-14 hours. The hepatic steatosis index (HSI) was employed to evaluate NAFLD, taking into account ALT/AST ratios, body mass index (BMI), and adjusting for sex and type 2 diabetes. Soft drink intake was gauged using a validated food frequency questionnaire (FFQ) and divided into three groups: less than one serving per week, 1 to less than 3.5 servings per week, and 3.5 or more servings per week. Zero-calorie/diet soft drinks were omitted from the analysis. Other variables, such as age, smoking habits, physical activity, health status, and alcohol consumption, were documented, as per news-medical.net.
Statistical modeling, primarily through fixed effects regression, was utilized to assess the relationship between SD consumption and NAFLD, adjusting for potential confounders. Generalized estimating equation (GEE) models were also employed to provide a robust analysis by accounting for both within- and between-subject variations. Sex-stratified analyses were conducted to examine potential metabolic distinctions. Ethical considerations were maintained with participant consent and institutional review board approval.
Findings
For male participants, the median age was 44.8 years, with a median SD consumption of 3.1 servings per week. Notably, 28% of males consumed 1 to <3.5 servings per week, while 47.4% reported SD intake exceeding 3.5 servings weekly. Female participants had a median age of 46.6 years, with 31.1% consuming 1 to <3.5 servings per week and 26.5% exceeding 3.5 servings per week.
Among males, higher SD consumption correlated with elevated ALT levels in the unadjusted analysis (β = 11.1; 95% CI: 3.2, 18.9). This remained significant after adjusting for confounding variables (β = 11.1; 95% CI: 2.9, 19.3 in model 2; β = 10.6; 95% CI: 2.5, 18.8 in model 3). Moreover, a higher risk of NAFLD, as indicated by HSI levels, was observed with increasing SD intake (β = 2.8; 95% CI: 0.5, 5.0). Age positively correlated with ALT, AST, truncal fat, and glucose in model 2, while truncal fat was associated with higher AST levels, and glucose correlated with elevated HSI scores in model 3, according to the reports by news-medical.net.
For females, although an initial association between SD consumption and higher AST, ALT, and NAFLD was noted, the statistical significance dissipated after adjustments. For instance, HSI levels increased with greater SD consumption (β = 0.9; 95% CI: -0.2, 1.9). Age remained positively associated with ALT, AST, truncal fat, and glucose in model 2, while truncal fat correlated with higher ALT and HSI levels, and glucose was associated with elevated HSI scores.
Fixed effects logistic regression models revealed a notable 39% increase in the likelihood of high HSI levels when SD consumption escalated from the lowest to the highest category (OR = 1.39; 95% CI: 0.98, 2.39). GEE model findings aligned with this, showing a 42% increase in NAFLD risk for those consuming the highest SD levels compared to the lowest (OR = 1.42; 95% CI: 1.15, 1.74), as per news-medical.net.
Conclusion
The findings underscore a significant connection between elevated SD intake and the risk of NAFLD, especially among males. While the statistical strength was less pronounced among females, the potential metabolic impact of soft drink consumption warrants further examination across broader population subsets.