Dyslipidemia, Impaired Glucose Tolerance
Conditions
Keywords
Hispanics, Single nucleotide polymorphism, Hepatic lipase
Brief summary
The investigators evaluated dietary modulation of LIPC rs1800588 (-514 C/T) for lipids and glucose using a randomized cross-over design comparing a high-fat Western diet and a low-fat traditional Hispanic diet in Caribbean Hispanics (n=42; 4 weeks/phase).
Detailed description
The LIPC -514 C/T single nucleotide polymorphism (SNP) has been inconsistently associated with high density lipoprotein cholesterol (HDL-C) in population studies, supporting the possibility of its modulation by dietary factors. To investigate the interaction between the common LIPC -514(C/T) SNP and dietary fat, the investigators compared changes in lipids and glucose in response to two levels of dietary total fat (20% energy intake vs. 39% energy intake) in a crossover, randomized dietary intervention study enrolling Caribbean Hispanics. Individuals were screened for LIPC rs1800588 genotype prior to enrollment, and genotype-associated differences in response to diet were evaluated. The study was designed to test the following hypotheses: 1. Carriers of the T allele consuming a low fat (LF) diet will have decreased hepatic lipase activity as compared with subjects with the CC genotype at the -514(C/T) polymorphism. Conversely, in individuals consuming a high fat (HF) diet, T carriers will exhibit an impaired ability to down regulate hepatic lipase activity. 2. Based on differences in hepatic lipase activity, the investigators hypothesized that a significant and clinically relevant proportion of the individual variability in fasting plasma HDL-C responses to changes in dietary fat intake would be due to variability at the LIPC locus. Specifically, CC subjects will respond to increases in total dietary fat consumption with significant increases in HDL-C concentration. Conversely, increased fat consumption in T carrying subjects will result in decreased HDL-C concentration.
Interventions
OTHERHigh-fat diet
Typical Western diet
OTHERLow-fat diet
Traditional Caribbean Hispanic diet
Sponsors
Tufts University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Self-reported Caribbean Hispanics
Exclusion criteria
* diabetes * uncontrolled hypertension * self-reported liver disease; severe kidney dysfunction; angina; endocrine disease; preexisting cardiovascular disease or gallbladder disease, or pancreatitis within the past 12 months * use of lipid-lowering or hypoglycemic medications * BMI \>34 kg/m2 * alcohol consumption (\>2 drinks/day) * smoking within the past 6 months or illegal drug use * pregnancy or breastfeeding * weight gain or loss of more than 9 kg within the past 6 months * extreme levels of physical or athletic activity, strict vegetarians/vegans * egg, wheat, milk, fish, or nut allergies * unwillingness to discontinue fish oil or flaxseed supplements or drinking alcohol during the study * travel plans precluding availability for the two 4-week study phases
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| change in fasting high-density lipoprotein cholesterol | From date of randomization until completion of each 4 week dietary intervention |
Secondary
| Measure | Time frame |
|---|---|
| change in fasting plasma triglycerides | From date of randomization until completion of the 4 week dietary intervention |
| change in fasting plasma glucose | From date of randomization until completion of the 4 week dietary intervention |
| oral glucose tolerance test | 2 hours post-oral glucose load |
| post-prandial lipemia 4 hours | 4 hours post-oral fat load |
| post-prandial lipemia 8 hours | 8 hours post-oral fat load |
Outcome results
None listed