Changes in serum triglycerides and high-density lipoprotein concentration and composition after a low-fat mixed meal. Effects of gender and insulin resistance

The effect of fasting status on lipids, lipoproteins, and inflammatory biomarkers assessed after hospitalization for an acute coronary syndrome: Insights from PROVE IT-TIMI 22

BACKGROUND

For decades, fasting for 8 to 12 hours has been recommended for measurement of lipid profiles. The effect of fasting on low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) has been described in healthy cohorts and those with stable disease states. Recently, guidelines suggested that fasting may not be necessary due to its small effect on lipid measures. Little is known, however, regarding whether the impact of fasting is altered in the setting of an acute coronary syndrome (ACS).

HYPOTHESIS

We hypothesized that the post-ACS period would minimally effect the impact of fasting status on lipid measurements.

METHODS

We evaluated the association of fasting on lipid and other biomarkers at the randomization visit, which occurred at a median of 7 days after the onset of an ACS, as well as during follow-up, in a cohort of 4177 subjects from the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction 22 (PROVE IT-TIMI 22) trial.

RESULTS

Fasting samples were independently associated with a higher LDL-C of 4.1 mg/dL and apolipoprotein-B 100 of 2.6 mg/dL as well as a lower TG of 21.0 mg/dL and high-sensitivity C-reactive protein of 0.48 mg/dL. The relative difference was 3.8% for LDL-C and -11.3% for TG. Fasting did not change total cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, lipoprotein(a), or apolipoprotein C-III.

CONCLUSIONS

Although fasting does impact lipid measurements, the effect on LDL-C is small (about 4 mg/dL), both early after ACS and during follow-up. These data provide support for recent guidelines that no longer advocate for fasting lipid samples, including in the setting of ACS.

Apolipoprotein B polymorphism distribution among a sample of obese Egyptian females with visceral obesity and its influence on lipid profile

Background

Regional distribution of adipose tissue is more important than total amount of body fat in predicting complications associated with obesity. Apolipoprotein B (Apo B) plays a central role in lipid metabolism.

Aim

To investigate the importance of the XbaI polymorphism of Apo B gene (C7673T) as risk factor for visceral obesity and its influence on lipid profile.

Subjects and methods

Total of 122 obese adult females (BMI ⩾ 30 kg/m²): 56 of them with visceral obesity (⩾7 cm by abdominal Ultrasound) and 66 without visceral obesity and 36 age matched non-obese (BMI ⩽ 25 kg/m²) without visceral obesity were studied. Anthropometric assessment, body composition, visceral obesity and lipid profile evaluation were attempted. Genetic analysis of Apo B XbaI was performed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP).

Results

Visceral obesity was associated significantly with the presence of the heterozygous (CT) genotype of the XbaI Apo B gene (p < 0.001). Frequency of homozygous (CC) was significantly the least genotype found in females with visceral obesity, while homozygote (TT) genotype was more frequent in those without visceral obesity. T allele (about 70%) was more frequent than C allele (about 30%) in all groups. Significant lowest values of visceral obesity, triglyceride and HDL-C were associated with the presence of (CC) genotype and the highest values were associated with the presence of the heterozygous (CT) genotype; except HDL-C with (TT) genotype.

Conclusions

Study reveals considerable association of Apo B XbaI gene polymorphism with visceral obesity and some lipid profile parameters (TG and HDL-C) among Egyptian females.

Casual serum triglyceride as a predictor of premature type 2 diabetes mellitus: an 8-year cohort study of middle-aged Japanese workers

Background

The utility of casual serum triglyceride (TG) as a predictor of type 2 diabetes mellitus (DM) is unclear, especially during the most productive years.

Methods

Participants were 3271 workers (913 men and 2358 women, age 20-57) without DM at baseline. They underwent consecutive annual medical check-ups for 8 years. The association between newly diagnosed DM and casual serum TG level was determined by classifying the participants into 4 groups according to casual serum TG level at baseline: below 50 mg/dL (group A), 50-100 mg/dL (group B), 100-150 mg/dL (group C), and ≥150 mg/dL (group D). The effects of casual serum TG level in combination with sex, obesity, or serum glucose level on newly diagnosed DM were also evaluated.

Results

A total of 222 newly diagnosed type 2 DM cases with a mean age of 50 years old were observed during the follow-up period, i.e., 10/406 in group A, 66/1534 in group B, 58/712 in group C, and 88/619 in group D. Compared with group A, the odds ratio (ORs) for newly diagnosed DM (after adjusting for DM-associated factors) was found to increase with casual serum TG level: 1.38 (group B), 1.79 (group C), and 2.36 (group D). Moreover, the OR for newly diagnosed DM was higher in participants with high casual serum TG levels who were also male (OR 2.46), obese (OR 4.18), or had a high serum glucose level (OR 6.96) than in the reference group.

Conclusions

Serum TG level ≥150 mg/dL when fasting or nonfasting is a significant predictor of type 2 diabetes in middle-aged Japanese workers.

Fasting time and lipid parameters: association with hepatic steatosis--data from a random population sample

Background

Current guidelines recommend measuring plasma lipids in fasting patients. Recent studies, however, suggest that variation in plasma lipid concentrations secondary to fasting time may be minimal. Objective of the present study was to investigate the impact of fasting time on plasma lipid concentrations (total cholesterol, HDL and LDL cholesterol, triglycerides). A second objective was to determine the effect of non-alcoholic fatty liver disease exerted on the above-mentioned lipid levels.

Method

Subjects participating in a population-based cross-sectional study (2,445 subjects; 51.7% females) were questioned at time of phlebotomy regarding duration of pre-phlebotomy fasting. Total cholesterol, LDL and HDL cholesterol, and triglycerides were determined and correlated with length of fasting. An upper abdominal ultrasonographic examination was performed and body-mass index (BMI) and waist-to-hip ratio (WHR) were calculated. Subjects were divided into three groups based on their reported fasting periods of 1–4 h, 4–8 h and > 8 h. After application of the exclusion criteria, a total of 1,195 subjects (52.4% females) were included in the study collective. The Kruskal-Wallis test was used for continuous variables and the chi-square test for categorical variables. The effects of age, BMI, WHR, alcohol consumption, fasting time and hepatic steatosis on the respective lipid variables were analyzed using multivariate logistic regression.

Results

At multivariate analysis, fasting time was associated with elevated triglycerides (p = 0.0047 for 1–4 h and p = 0.0147 for 4–8 h among females; p < 0.0001 for 1–4 h and p = 0.0002 for 4–8 h among males) and reduced LDL cholesterol levels (p = 0.0003 for 1–4 h and p = 0.0327 for 4–8 h among males). Among males, hepatic steatosis represents an independent factor affecting elevated total cholesterol (p = 0.0278) and triglyceride concentrations (p = 0.0002).

Conclusion

Total and HDL cholesterol concentrations are subject to slight variations in relation to the duration of the pre-phlebotomy fasting period. LDL cholesterol and triglycerides exhibit highly significant variability; the greatest impact is seen with the triglycerides. Fasting time represents an independent factor for reduced LDL cholesterol and elevated triglyceride concentrations. There is a close association between elevated lipids and hepatic steatosis.

The impact of dyslipidaemia on incidence of coronary heart disease in Finns and Swedes with different categories of glucose tolerance

BACKGROUND

The association of dyslipidaemia with incidence of coronary heart disease (CHD) has not been well studied in people with different glucose categories.

METHODS

Data from six population-based prospective studies in Finland and Sweden, with 4818 men and 4269 women aged 25-89 years who were free of CHD and without a prior history of diabetes at baseline, were jointly analysed. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for CHD incidence were estimated.

RESULTS

457 participants developed CHD during follow-up of 10 years. The multivariate adjusted HRs (95% CIs) for CHD incidence were 1.39 (1.08-1.80), 0.57 (0.39-0.84), 1.21 (1.07-1.37), 1.56 (1.21-2.01) and 1.74 (1.34-2.26), respectively, corresponding to a one unit increase in Z-scores of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), non-HDL-C and TC to HDL ratio, in people with newly diagnosed diabetes. The prediction was also significant in non-diabetic population except for TG in individuals with normoglycaemia and TG and HDL-C in those with isolated IFG.

CONCLUSION

Adverse lipid profiles were related to increased CHD incidence in normoglycaemic, fasting hyperglycaemic and diabetic individuals, but not in people with IGT. The findings may imply considering different management strategies in people with fasting or post-load hyperglycaemia.