Applied nutritional investigationNutrient intake in Italian obese patients: Relationships with insulin resistance and markers of non-alcoholic fatty liver disease
Introduction
Obesity could be considered a systemic disease due to its widespread effects on several organs, above all the cardiovascular system and the liver. Endogenous (genetic) and exogenous (dietary habits and decreased/absent physical activity) components play important roles in the pathogenesis of obesity and related metabolic disorders.
Insulin resistance (IR) represents the main link among obesity, metabolic syndrome, and liver disease with fat accumulation, i.e., non-alcoholic fatty liver disease (NAFLD) [1], [2]. In most obese patients, NAFLD remains stable for many years. However, in a subset of these patients, it may worsen to non-alcoholic steatohepatitis and liver cirrhosis. Progression depends on the degree of liver fibrosis. Identifying the presence and severity of liver fibrosis in patients with NAFLD is therefore of major importance for the management of such patients. In contrast, the general criterion for referral to liver units is the presence of higher than normal levels of enzymes alanine aminotransferase (ALT) and γ-glutamyltranspeptidase (GGT) [3]. However, recent studies have demonstrated that, despite normal enzyme levels, histologic hepatic features with increased risk of progression have been observed in obese patients; therefore, it is not clear whether normal ALT levels can exclude patients with NAFLD from the need for liver biopsy [4]. Although liver biopsy is widely recognized as the only reliable means for determining the severity of fibrosis, it is an invasive procedure associated with many complications. Serum markers and new technologies, such as ultrasonography-based elastography (FibroScan®, Echosens, Paris, France), have recently been reported as non-invasive procedures for monitoring NAFLD in obese patients [5]. The combination of serum and clinical markers may also be useful to predict the severity of liver fibrosis in such patients. Among the non-invasive panels of tests, a simple scoring system, the NAFLD Fibrosis Score (NFS), could be considered quite reliable for distinguishing between NAFLD with and without the probability of fibrosis [6], [7], [8].
Conversely, although dietary habits are strongly related to the development of obesity and IR, few investigations have used nutritional assessment in obese subjects to demonstrate the relations between dietary constituents and the development or progression of metabolic and liver disorders in obesity.
The aims of this study were to 1) evaluate the prevalence of IR and markers of hepatic dysfunction in an Italian cohort of obese and severely obese patients; 2) identify the characteristics of dietary habits and nutrient intakes in obese patients by detailed questioning; 3) compare IR and the suggested NAFLD markers with nutrient intakes in three subgroups according to obesity classification; and 4) investigate the possible relations among IR, hepatic markers, and inadequate dietary intakes (nutrients and energy) in our obese population.
Section snippets
Materials and methods
From January through September 2009, 63 consecutive obese (body mass index [BMI] >30 kg/m2) patients (21 men and 42 women, mean age 41.1 ± 10.5 y, age range 19–68 y) were admitted to our digestive endoscopy service for bariatric treatment of obesity.
Clinical, laboratory, and metabolic determinations were assessed for each patient, under informed consent. Exclusion criteria were a positive finding for hepatitis B or C virus, previous or current alcohol consumption higher than 30 g/d, use of
Results
Clinical, laboratory, and demographic data are presented in Table 1. The BMI ranged from 30.9 to 73.7 kg/m2 and most patients (53%) were in class III (BMI ≥40 kg/m2), i.e., severe obesity. Waist circumference ranged from 81 to 194 cm. A “bright liver” echo pattern at ultrasound investigation, consistent with liver steatosis, was observed in 63%. Impaired fasting blood glucose (≥110 mg/dL) was observed in 24%. HOMA values ranged from 0.78 to 17.6 and indicated IR (>2.5) in 63.5% of all patients.
Discussion
Insulin resistance and NAFLD are commonly observed in most obese subjects, suggesting a close relation between visceral fat and liver injury due to increased circulating insulin levels [17], [18]. The exact mechanisms underlying the progression of liver damage have not yet been sufficiently clarified. However, fat accumulation and oxidative hepatocellular injury are considered the two unavoidable steps leading to non-alcoholic steatohepatitis and advanced fibrosis [6], [7], [8]. Conflicting
Conclusions
Non-normal ALT and GGT were observed in less than one-third of all patients, although the prevalent elevation of HOMA-IR and NFS over their respective cutoffs showed the severity of metabolic and hepatic disorders in our patients. The high intake of protein, especially animal protein, was associated with an increased risk of IR. The carbohydrate intake, albeit at the highest limit of the RDA range, was associated with an increased risk of liver fibrosis.
References (27)
- et al.
Nonalcoholic fatty liver disease, steatohepatitis and metabolic syndrome
Hepatology
(2003) - et al.
Comparison of noninvasive markers of fibrosis in patients with nonalcoholic fatty liver disease
Clin Gastroenterol Hepatol
(2009) - et al.
The role of bright liver echo pattern on ultrasound B-mode examination in the diagnosis of liver steatosis
Dig Liver Dis
(2006) - et al.
Effect of the BioEnterics intragastric balloon on weight, insulin resistance, and liver steatosis in obese patients
Gastrointest Endosc
(2010) - et al.
Dietary habits and nutrient intake in non-alcoholic steatohepatitis
Nutrition
(2007) - et al.
High-fat diet: a trigger of non-alcoholic steatohepatitis? Preliminary findings in obese patients
Nutrition
(2008) - et al.
Effect of 6-month nutritional intervention on non-alcoholic fatty liver disease
Nutrition
(2010) - et al.
How different is the dietary pattern in non-alcoholic steatohepatitis patients?
Clin Nutr
(2006) - et al.
Age and disability affect dietary intake
J Nutr
(2003) Non alcoholic fatty liver disease
N Engl J Med
(2002)
Aminotransferase and gamma-glutamyltranspeptidase levels in obesity are associated with insulin resistance and the metabolic syndrome
J Endocrinol Invest
Risk of severe liver disease in nonalcoholic fatty liver disease with normal aminotransferase levels: a role for insulin resistance and diabetes
Hepatology
Diagnostic value of biochemical markers (FibroTest-FibroSURE) for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease
BMC Gastroenterol
Cited by (29)
The Association of Maternal Protein Intake during Pregnancy in Humans with Maternal and Offspring Insulin Sensitivity Measures
2019, Current Developments in NutritionThe impact of dietary fibres on the physiological processes governing small intestinal digestive processes
2015, Bioactive Carbohydrates and Dietary FibreCitation Excerpt :Non-alcoholic fatty liver disease is defined as the excess build-up of parenchymal fat in the liver in the absence of excessive habitual alcohol consumption (Than & Newsome, 2015). A recent observational study suggested no association of dietary intake with markers of severity of non-alcoholic fatty liver disease (Ricci et al., 2011), highlighting the need for larger, longer-term studies in the future. Such studies may be challenging using existing longitudinal datasets, as non-alcoholic fatty liver disease diagnosis has been historically difficult and the condition is associated with many co-morbidities (Abd El-Kader & El-Den Ashmawy, 2015).
A cross-sectional study assessing dietary intake and physical activity in canadian patients with nonalcoholic fatty liver disease vs healthy controls
2014, Journal of the Academy of Nutrition and DieteticsCitation Excerpt :However, we found similar prevalence of low PUFA intake in our healthy controls, suggesting that low PUFA intake alone might not be a determinant for NAFLD. Recent studies suggest that high carbohydrate intake is also associated with a greater risk of hepatic inflammation and fibrosis.55-57 We could not clearly confirm this relationship, as the carbohydrate intake was largely adequate in simple steatosis and NASH, and there was no difference between patients and healthy controls.
Non-alcoholic fatty liver disease in children now: Lifestyle changes and pharmacologic treatments
2012, NutritionCitation Excerpt :Weight loss is accomplished primarily by lifestyle interventions, which are non-pharmacologic treatments including personalized diets and proper exercise. Several studies in adults have demonstrated that lifestyle modifications, based on a dietary restriction and the promotion of physical activity, can lead to significant decreases in body weight/body mass index and an improvement of liver function tests and liver histology [15–17]. However, little information currently exists about the impact of specific diet and physical activity patterns on childhood NAFLD [18,19].
Protein Intake Among Patients with Insulin-Treated Diabetes is Linked to Poor Glycemic Control: Findings of NHANES Data
2022, Diabetes, Metabolic Syndrome and Obesity