Non-alcoholic Fatty Liver Disease (NAFLD)
Conditions
Keywords
Hepatic mitochondrial dysfunction, Non-alcoholic Fatty Liver Disease NAFLD, 13C-α-Ketoisocaproic Acid Breath Test, liver stiffness
Brief summary
The goal of this observational, cross-sectional, case-control clinical study is to investigate the metabolic adaptations underlying the progression of nonalcoholic fatty liver disease (NAFLD), and to test the hypothesis that hepatic mitochondrial reductive stress contributes to progression of NAFLD. The main question it aims to answer is: Do patients with advanced NAFLD compared to patients with mild NAFLD and healthy controls have increased hepatic mitochondrial reductive stress as determined by the ketoisocaproate breath test and by plasma beta-hydroxybutyrate to acetoacetate ratio (b-OHB/AcAc)?
Detailed description
In this study the investigators study the metabolic adaptations underlying the progression of nonalcoholic fatty liver disease (NAFLD), namely hepatic mitochondrial reductive stress, ureagenesis, de novo lipogenesis and gluconeogenesis in patients with advanced and mild NAFLD and in healthy controls. At the first visit, an informed consent will be obtained, followed by assessment of inclusion/exclusion criteria and medical history. Participants fulfilling the criteria will be enrolled in the study. A physical examination will be performed and laboratory test will be taken. Body composition will be determined with bioelectrical impedance and dual-energy x-ray absorptiometry (DEXA). At the second visit, hepatic lipid content will be measured with magnetic resonance spectroscopy. At the third visit, participants will pick up containers for overnight urine collection and doses of deuterated water and a standardized meal replacement bar. The fourth visit is a clinical study visit. In a specified order, participants will drink tracer doses of 15NH4Cl, 13C-bicarbonate and 13C-alpha-ketoisocaproate. An oral glucose tolerance test is performed in the end of the study day. Breath samples are collected at different time points for determination of 13C enrichment of CO2. Furthermore, arterialized blood samples are taken to obtain beta-hydroxybutyrate to acetoacetate ratios (b-OHB/AcAc) at different timepoints. Whole-body oxidation of lipids, carbohydrates and protein will be determined using indirect calorimetry.
Interventions
DIAGNOSTIC_TESTKetoisocaproic acid breath test
13C-alpha-ketoisocaproic acid breath test to estimate hepatic mitochondrial reductive stress (1 mg/kg body weight; oral dose; study duration 390 min)
DIAGNOSTIC_TESTAmmonium Chloride
15N-ammonium chloride stable isotope test to estimate ureagenesis (20 mg/kg body weight; oral dose; study duration 390 min)
DIAGNOSTIC_TESTBicarbonate de sodium
13C-bicarbonate breath test to estimate body bicarbonate pool size and gastric emptying (0.5 mg/kg body weight; oral dose; study duration 390 min)
DIAGNOSTIC_TESTDeuterated Water
Deuterated water stable isotope test to estimate hepatic de novo lipogenesis and gluconeogenesis (3 g/kg body water; oral dose; duration: overnight)
DIAGNOSTIC_TESTOral Glucose Tolerance Test
A standard 2-hour 75-gram oral glucose tolerance test to assess glucose tolerance and whole body metabolism
Sponsors
Helsinki University Central Hospital
Study design
Observational model
CASE_CONTROL
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
Yes
Inclusion criteria
The following inclusion/
Exclusion criteria
will be employed: 1. Participants must be able to communicate meaningfully with the investigator and must be legally competent to provide written informed consent. 2. Subject must be likely to be available to complete all protocol-required study visits or procedures, to the best of the subject's and investigator's knowledge. 3. Participants must be aged between 18-75 years. 4. Participants are not allowed to have alcohol consumption of 350 g/week or more in women and 420 g/week or more in men. 5. Participants are not allowed to have history of liver disease other than NAFLD as judged by history and physical examination and standard laboratory tests. 6. Participants are not allowed to have claustrophobia or metal implants to allow magnetic resonance studies. 7. Participants are not allowed to be pregnant or lactating. 8. No known or anticipated difficulties in cannulation of peripheral veins. 9. No history or evidence of any other clinically significant disorder, condition or disease other than those outlined above that, in the opinion of the investigator may compromise the ability of the subject to give written informed consent, would pose a risk to subject safety, or interfere with the study evaluation, procedures or completion.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Hepatic mitochondrial reductive stress as determined by plasma beta-hydroxybutyrate-to-acetoacetate ratio | Fourth study visit (2 months) | Ratio of beta-hydroxybutyrate and acetoacetate concentrations in arterialized plasma |
| Hepatic mitochondrial reductive stress as determined by the ketoisocaproic acid breath test | Fourth study visit (2 months) | Breath 13CO2 enrichment after ingesting 13C-alpha-ketoisocaproate measured as area under the curve |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Plasma metabolomics | Fourth study visit (2 months) | Arterialized plasma analyzed by nuclear magnetic resonance |
Other
| Measure | Time frame | Description |
|---|---|---|
| Ammonia incorporation to glutamine | Fourth study visit (2 months) | Hepatic incorporation of ammonia to glutamine (i.e. glutamine synthesis), as determined by plasma \[15N1\]glutamine enrichment after ingestion of a tracer dose of 15NH4Cl |
| Fractional Rate of Ureagenesis | Fourth study visit (2 months) | Hepatic incorporation of ammonia to urea (i.e. ureagenesis), as determined by plasma \[15N1\]urea enrichment after ingestion of a tracer dose of 15NH4Cl |
| Bicarbonate pool size | Fourth study visit (2 months) | Breath 13CO2 enrichment after ingesting 13C-bicarbonate measured as area under the curve |
| Fractional Rate of Hepatic de novo lipogenesis | Fourth study visit (2 months) | Hepatic de novo lipogenesis, as determined by deuterium enrichment in plasma triglyceride-palmitate after ingestion of tracer doses of deuterated water |
| Fractional Rate of Gluconeogenesis | Fourth study visit (2 months) | Fractional gluconeogenesis, as determined by deuterium enrichment in plasma glucose after ingestion of tracer doses of deuterated water |
Countries
Finland
Outcome results
None listed