Hypercholesterolemia and Hyperlipidemia
Conditions
Keywords
LDL-cholesterol, cholesterol, ketogenic diet, lipoprotein kinetics
Brief summary
Very-low carbohydrate ketogenic diets can dramatically increase blood cholesterol levels, particularly in normal-weight people, for reasons that are not well understood. This study will enroll normal-weight adults, will identify "responders" who develop high cholesterol on a ketogenic diet, and will measure rates of production and removal of certain types of cholesterol-carrying particles called lipoproteins in responders. The results will clarify the mechanism by which a ketogenic diet can cause high cholesterol in certain susceptible people.
Detailed description
This study will evaluate the mechanism of ketogenic diet-induced hypercholesterolemia in susceptible normal-weight adults. The first stage of screening will identify eligible young adults who are normal-weight and at low cardiovascular risk. The second stage of screening will identify "responders" who demonstrate susceptibility to ketogenic diet-induced hypercholesterolemia by displaying an increase in LDL-cholesterol concentration after a 3-week screening ketogenic diet. Responders will be eligible to complete a randomized crossover clinical study at Washington University School of Medicine in St. Louis, MO. The randomized crossover study will involve isotope tracer studies of lipoprotein and cholesterol kinetics after two separate 4-week dietary interventions \[ketogenic diet and control diet\], conducted in random order with a 4-week washout period between interventions. All food will be provided to the participants as packed-out meals. Certain outcomes will use data from the screening process, comparing screen successes and screen failures to evaluate factors that could influence susceptibility to ketogenic diet-induced hypercholesterolemia.
Interventions
BEHAVIORALKetogenic Diet
Participants will consume an isocaloric ketogenic diet for 4 weeks with all food provided as packed-out meals.
BEHAVIORALControl Diet
Participants will consume an isocaloric control diet for 4 weeks with all food provided as packed-out meals.
Sponsors
Washington University School of Medicine
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 39 Years
Healthy volunteers
Yes
Inclusion criteria
1. age ≥ 18 and \< 40 years 2. BMI ≥ 18.5 and \< 25.0 kg/m2 3. baseline serum LDL-c \< 150 mg/dL (\< 3.9 mmol/L) 4. baseline serum TG \< 100 mg/dL (\< 1.1 mmol/L) 5. HbA1c ≤ 5.6%.
Exclusion criteria
1. personal or family history of familial hypercholesterolemia 2. current use of lipid-lowering drugs 3. currently on a ketogenic diet and unwilling to change diet 4. current tobacco use 5. hypertension 6. prediabetes or diabetes 7. elevated Lp(a) \> 6.5% of ApoB-containing lipoproteins at baseline 8. oral contraceptive use 9. contraindication to heparin 10. known atherosclerotic cardiovascular disease 11. unwilling to abstain from alcohol
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| VLDL-ApoB100 production rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and VLDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| VLDL-ApoB100 fractional catabolic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and VLDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
| IDL-ApoB100 production rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and IDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
| IDL-ApoB100 fractional catabolic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and IDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
| LDL-ApoB100 production rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and LDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
| LDL-ApoB100 fractional catabolic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and LDL-ApoB100 leucine isotopic enrichment and compartmental modeling |
| VLDL-triglyceride production rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and VLDL glycerol isotopic enrichment and compartmental modeling |
| VLDL-triglyceride fractional catabolic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and VLDL glycerol isotopic enrichment and compartmental modeling |
| Plasma lipoprotein lipase activity | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by assaying lipoprotein lipase activity in post-heparin plasma |
| Plasma lipoprotein profile | At baseline, immediately after the screening ketogenic diet, immediately after the 4-week ketogenic diet intervention period, and immediately after the 4-week control diet intervention period. | Determined by standard clinical chemistry methods and by advanced lipoprotein profiling |
| Whole-body lipolytic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma palmitate isotopic enrichment |
| Relative contribution of systemic fatty acids to VLDL-triglyceride | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using plasma and VLDL-triglyceride palmitate isotopic enrichment and compartmental modeling |
| Cholesterol synthetic rate | Immediately after the 4-week ketogenic diet intervention period and immediately after the 4-week control diet intervention period. | Determined by using mass isotopomer distribution analysis of deuterium enrichment in plasma cholesterol after labeling the total body water pool with deuterium oxide |
| Fat mass | Immediately after the screening ketogenic diet | Determined by using dual-energy X-ray absorptiometry |
| Fat-free mass | Immediately after the screening ketogenic diet | Determined by using dual-energy X-ray absorptiometry |
| Insulin sensitivity | Immediately after the screening ketogenic diet | Determined by measuring fasting plasma glucose, insulin, and C-peptide |
| Thyroid function | Immediately after the screening ketogenic diet | Determined by measuring TSH, free T4, and free T3 |
| Adipokines | Immediately after the screening ketogenic diet | Determined by measuring plasma leptin and adiponectin |
| Cholesterol absorption markers | Immediately after the screening ketogenic diet | Determined by measuring serum campesterol, sitosterol, and cholestanol |
Countries
United States
Contacts
CONTACTFrannie Wilkinson, M.A.
CONTACTMax C Petersen, M.D., Ph.D.
PRINCIPAL_INVESTIGATORMax C Petersen, M.D., Ph.D.
Washington University School of Medicine
Outcome results
None listed