Non-alcoholic Fatty Liver Disease (NAFLD)
Conditions
Keywords
Sugars, Fatty liver, Lipoprotein kinetics, Triglycerides
Brief summary
The hypothesis of this study is that a diet high in sugars will increase abnormalities in blood lipids which are associated with increased cardiovascular disease risk, relative to a diet which is low in sugar. We predict that this potentially adverse effect of dietary sugars on blood lipids will be more pronounced in people with a raised level of stored fat inside their liver, as compared to people with a low level of stored fat.
Detailed description
This study aims to determine the metabolic mechanism(s) by which dietary extrinsic sugars (sucrose and fructose), promote the formation of a high risk dyslipidaemia, known as an atherogenic lipoprotein phenotype (raised plasma triglyceride, low HDL and predominance of small, dense LDL), in men with raised cardio-metabolic risk and percentage of liver fat, as determined by magnetic resonance spectroscopy (MRS). The study examined the impact of diets high and low in extrinsic sugars, on the metabolism of lipids and lipoproteins in vivo, of two groups of men with a high (\>10%)and low (\<2%)percentage of liver fat, by the trace-labelling of these lipid moieties with stable isotopes, and detection by gas chromatography mass spectrometry. The study had a two-way cross-over design, with two, 12 week dietary interventions separated by a six week wash-out period. The dietary intervention with high and low sugars was achieved by a dietary exchange with supermarket foods, which were consumed within the homes of the participants.
Interventions
OTHERHigh sugar low starch diet
OTHERLow sugar high starch diet
Sponsors
Imperial College London
University of Cambridge
Bruce A. Griffin
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Male gender, * Increased cardio-metabolic risk ('RISCK' criteria Jebb et al (2010) Am J Clin Nutr 92, 748-758). * Apo E3E3 genotype
Exclusion criteria
* Any abnormal result in blood screen (renal and liver function, haematology) * Diabetes * Smoker * Excessive alcohol consumption (\>27units/week) * Medication likely to affect lipid metabolism * \>3kg weight loss in preceding 3 months * Any medical condition (eg. GI tract, allergies) affecting lipid metabolism or ability to comply with dietary interventions * Involvement in any other study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Production Rate of VLDL-1 Triacylglycerol (TAG) | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | The in vivo production rate of VLDL-1 TAG, trace-labelled with \[1,1,2,3,3-H5\] glycerol, measured in units of grams/day. |
| Production Rate VLDL-1 Apoprotein B | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | The in vivo production rate of VLDL-1 apoprotein B, trace-labelled with \[I-13C\] leucine (leucine with carbon-13), measured in units of milligrams/day. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | Palmitate was labelled in vivo by the infusion of \[U-13 carbon\]. This provides a measure of the rate of intra-cellular lipolysis and contribution of systemic palmitate to the synthesis of triacylglycerol in the liver in units of micro mols/L (umol/L). |
| De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | Acetyl CoA (Co-enzyme-A) is labelled in vivo by the consumption of \[2H20\] (2H20=deuterated 'heavy'-labelled water). Recovery and detection of this label in VLDL-1 by GC-MS (Gas Chromatography-Mass Spectrometry), provides a measure of fatty acid and TAG synthesis in the liver in terms of its contribution to the production rate of VLDL-1 TAG in units of grams/day. |
| Intra-hepatocellular Lipid (IHCL) or % Liver Fat | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | Percentage of intra-hepatocellular lipid (IHCL or % liver fat) was measured by magnetic resonance spectroscopy (MRS). |
| Plasma Concentration of Triacylglycerol | After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14) | Plasma concentration of triacylglycerol (TAG) was measured in the post-absorptive state (after 12h fast) and expressed in units of mmol/L (shown as log transformed geometric means) |
Countries
United Kingdom
Participant flow
Recruitment details
Participants were recruited over a period of 24 months (2009-2011) at the 'CEDAR' Centre for Endocrinology and Diabetes Research, Royal Surrey County Hospital, Guildford, Surrey, United Kingdom.
Pre-assignment details
Men were selected on the basis of expressing increased cardio-metabolic risk and APOE E3E3 genotype. The men were screened for intracellular hepatic fat by magnetic resonance spectroscopy (MRS) and divided into two groups: low liver fat Controls (\<5% liver fat) and non-alcoholic fatty liver disease (NAFLD) with percentage liver fat \>5%.
Participants by arm
| Arm | Count |
|---|---|
| NAFLD (>5% Liver Fat) Men with non-alcoholic fatty liver disease (NAFLD) n=12 | 12 |
| Controls (<5% Liver Fat) Controls (men without NAFLD \<5% liver fat) n=15 | 15 |
| Total | 27 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| First Dietary Intervention (12 Weeks) | Withdrawal by Subject | 1 | 1 | 0 | 0 |
Baseline characteristics
| Characteristic | Controls (<5% Liver Fat) | Total | NAFLD (>5% Liver Fat) |
|---|---|---|---|
| Age, Continuous | 54 years STANDARD_DEVIATION 7.3 | 57 years STANDARD_DEVIATION 6.7 | 59 years STANDARD_DEVIATION 4.7 |
| Body mass index | 28.5 kg/m2 STANDARD_DEVIATION 1.5 | 28.6 kg/m2 STANDARD_DEVIATION 1.4 | 28.8 kg/m2 STANDARD_DEVIATION 1.4 |
| Body weight | 89.6 kilograms STANDARD_DEVIATION 9.1 | 89.7 kilograms STANDARD_DEVIATION 8.4 | 89.7 kilograms STANDARD_DEVIATION 7.8 |
| Diastolic blood pressure | 83 mmHg STANDARD_DEVIATION 9 | 85 mmHg STANDARD_DEVIATION 11 | 85 mmHg STANDARD_DEVIATION 13 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Serum cholesterol | 5.51 mmol/L STANDARD_DEVIATION 1 | 5.70 mmol/L STANDARD_DEVIATION 1 | 5.90 mmol/L STANDARD_DEVIATION 0.83 |
| Serum glucose | 5.46 mmol/L STANDARD_DEVIATION 0.45 | 5.58 mmol/L STANDARD_DEVIATION 0.43 | 5.73 mmol/L STANDARD_DEVIATION 0.45 |
| Serum HDL cholesterol | 1.34 mmol/L STANDARD_DEVIATION 0.3 | 1.34 mmol/L STANDARD_DEVIATION 0.29 | 1.35 mmol/L STANDARD_DEVIATION 0.28 |
| Serum triacylglycerol | 1.51 mmol/L STANDARD_DEVIATION 0.87 | 1.70 mmol/L STANDARD_DEVIATION 0.9 | 2.05 mmol/L STANDARD_DEVIATION 0.88 |
| Sex: Female, Male Female | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 15 Participants | 27 Participants | 12 Participants |
| Systolic blood pressure | 132 mmHg STANDARD_DEVIATION 13 | 133 mmHg STANDARD_DEVIATION 16 | 134 mmHg STANDARD_DEVIATION 19 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 11 | 0 / 11 | 0 / 14 | 0 / 14 |
| serious Total, serious adverse events | 0 / 11 | 0 / 11 | 0 / 14 | 0 / 14 |
Outcome results
Primary
Production Rate of VLDL-1 Triacylglycerol (TAG)
The in vivo production rate of VLDL-1 TAG, trace-labelled with \[1,1,2,3,3-H5\] glycerol, measured in units of grams/day.
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: men with non-alcoholic fatty liver disease (NAFLD) raised liver fat (\>5%) n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | Production Rate of VLDL-1 Triacylglycerol (TAG) | 20.9 grams/day | Standard Error 2.1 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | Production Rate of VLDL-1 Triacylglycerol (TAG) | 18.9 grams/day | Standard Error 2.1 |
| High Sugar Diet (12 Weeks) in Controls | Production Rate of VLDL-1 Triacylglycerol (TAG) | 16.6 grams/day | Standard Error 1.4 |
| Low Sugar Diet (12 Weeks) in Controls | Production Rate of VLDL-1 Triacylglycerol (TAG) | 12.4 grams/day | Standard Error 1.2 |
Comparison: The sample size of the NAFDL \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B \& TAG production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TAG (α=33%). A paired comparison of two diets (5% level), gave sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: <0.05Mixed Models Analysis
Primary
Production Rate VLDL-1 Apoprotein B
The in vivo production rate of VLDL-1 apoprotein B, trace-labelled with \[I-13C\] leucine (leucine with carbon-13), measured in units of milligrams/day.
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: NAFLD; men with raised liver fat ( \>5%), n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | Production Rate VLDL-1 Apoprotein B | 481 mg/day | Standard Error 76 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | Production Rate VLDL-1 Apoprotein B | 492 mg/day | Standard Error 58 |
| High Sugar Diet (12 Weeks) in Controls | Production Rate VLDL-1 Apoprotein B | 546 mg/day | Standard Error 56 |
| Low Sugar Diet (12 Weeks) in Controls | Production Rate VLDL-1 Apoprotein B | 414 mg/day | Standard Error 54 |
Comparison: The sample size for NAFLD \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B and triacylglycerol production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TG (α=33%). A paired comparison of two diets (5% level) produced sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: <0.05Mixed Models Analysis
Secondary
De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate
Acetyl CoA (Co-enzyme-A) is labelled in vivo by the consumption of \[2H20\] (2H20=deuterated 'heavy'-labelled water). Recovery and detection of this label in VLDL-1 by GC-MS (Gas Chromatography-Mass Spectrometry), provides a measure of fatty acid and TAG synthesis in the liver in terms of its contribution to the production rate of VLDL-1 TAG in units of grams/day.
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: NAFLD; men with raised liver fat ( \>5%), n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate | 1.66 grams/day | Standard Error 0.39 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate | 1.59 grams/day | Standard Error 0.34 |
| High Sugar Diet (12 Weeks) in Controls | De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate | 1.32 grams/day | Standard Error 0.43 |
| Low Sugar Diet (12 Weeks) in Controls | De Novo Lipogenesis (Rate of Triacylglycerol (TAG) Synthesis in the Liver) as Measured by Contribution to VLDL-1 TAG Production Rate | 0.56 grams/day | Standard Error 0.14 |
Comparison: The sample size of the NAFDL \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B \& TAG production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TG (α=33%). A paired comparison of two diets (5% level), gave sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: <0.05Mixed Models Analysis
Secondary
Intra-hepatocellular Lipid (IHCL) or % Liver Fat
Percentage of intra-hepatocellular lipid (IHCL or % liver fat) was measured by magnetic resonance spectroscopy (MRS).
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: NAFLD; men with raised liver fat ( \>5%), n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | Intra-hepatocellular Lipid (IHCL) or % Liver Fat | 24.2 Percentage of liver fat | Standard Error 6.8 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | Intra-hepatocellular Lipid (IHCL) or % Liver Fat | 14.2 Percentage of liver fat | Standard Error 3.2 |
| High Sugar Diet (12 Weeks) in Controls | Intra-hepatocellular Lipid (IHCL) or % Liver Fat | 3.6 Percentage of liver fat | Standard Error 1.3 |
| Low Sugar Diet (12 Weeks) in Controls | Intra-hepatocellular Lipid (IHCL) or % Liver Fat | 1.5 Percentage of liver fat | Standard Error 0.3 |
Comparison: The sample size of the NAFDL \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B \& TAG production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TG (α=33%). A paired comparison of two diets (5% level), gave sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: >0.05Mixed Models Analysis
Secondary
Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate
Palmitate was labelled in vivo by the infusion of \[U-13 carbon\]. This provides a measure of the rate of intra-cellular lipolysis and contribution of systemic palmitate to the synthesis of triacylglycerol in the liver in units of micro mols/L (umol/L).
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: NAFLD; men with raised liver fat ( \>5%), n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate | 169 umol/L | Standard Error 11 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate | 147 umol/L | Standard Error 12 |
| High Sugar Diet (12 Weeks) in Controls | Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate | 168 umol/L | Standard Error 15 |
| Low Sugar Diet (12 Weeks) in Controls | Kinetics of Systemic Non-esterified Fatty Acids by [C-13]-Trace-labelled Palmitate | 168 umol/L | Standard Error 17 |
Comparison: The sample size of the NAFDL \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B \& TAG production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TG (α=33%). A paired comparison of two diets (5% level), gave sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: <0.05Mixed Models Analysis
Secondary
Plasma Concentration of Triacylglycerol
Plasma concentration of triacylglycerol (TAG) was measured in the post-absorptive state (after 12h fast) and expressed in units of mmol/L (shown as log transformed geometric means)
Time frame: After (post-diet) two 12 week diets (high sugar versus low sugar) in men with NAFLD (n=11) versus Controls (n=14)
Population: Population consisted of two groups: Group 1: NAFLD; men with raised liver fat ( \>5%), n=11. Group 2: Controls; men with low liver fat (\<5%) n=14.
| Arm | Measure | Value (GEOMETRIC_MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet (12 Weeks) in Men With NAFLD | Plasma Concentration of Triacylglycerol | 2.05 mmol/L | Standard Error 0.24 |
| Low Sugar Diet (12 Weeks) in Men With NAFLD | Plasma Concentration of Triacylglycerol | 1.77 mmol/L | Standard Error 0.22 |
| High Sugar Diet (12 Weeks) in Controls | Plasma Concentration of Triacylglycerol | 1.33 mmol/L | Standard Error 0.15 |
| Low Sugar Diet (12 Weeks) in Controls | Plasma Concentration of Triacylglycerol | 1.13 mmol/L | Standard Error 0.08 |
Comparison: The sample size of the NAFDL \& Control groups was based on primary outcome measures for a trace-labelling study of VLDL kinetics (VLDL1 apo B \& TAG production rates). From the literature there was an 80% probability that our study will detect a difference in the production rates of VLDL1 apo B of 30% (α=39%), and 26% for VLDL1-TG (α=33%). A paired comparison of two diets (5% level), gave sample sizes of n=15 for each group. Note: All reported P-values were calculated.p-value: <0.05Mixed Models Analysis