Gemfibrozil and Mediterranean diet for patients with high plasma levels of lipoprotein [Lp(a)] and cholesterol--pilot study

Genetic and nutritional factors determining circulating levels of lipoprotein(a): results of the "Montignoso Study"

Increasing evidence shows an association between high lipoprotein(a) [Lp(a)] levels and atherothrombotic diseases. Lp(a) trait is largely controlled by kringle-IV type 2 (KIV-2) size polymorphism in LPA gene, encoding for apo(a). Environmental factors are considered to determinate minor phenotypic variability in Lp(a) levels. In the present study, we investigated the possible gene-environment interaction between KIV-2 polymorphism and Mediterranean diet adherence or fish weekly intake in determining Lp(a) levels. We evaluated Lp(a), KIV-2 polymorphism, fish intake and Mediterranean diet adherence in 452 subjects [median age (range) 66 (46-80)years] from Montignoso Heart and Lung Project (MEHLP) population. In subjects with high KIV-2 repeats number, influence of Mediterranean diet adherence in reducing Lp(a) levels was observed (p = 0.049). No significant difference in subjects with low KIV-2 repeats according to diet was found. Moreover, in high-KIV-2-repeat subjects, we observed a trend towards influence of fish intake on reducing Lp(a) levels (p = 0.186). At multivariate linear regression analysis, high adherence to Mediterranean diet remains a significant and independent determinant of lower Lp(a) levels (β = - 64.97, standard error = 26.55, p = 0.015). In conclusion, this study showed that only subjects with high KIV-2 repeats can take advantage to lower Lp(a) levels from correct nutritional habits and, in particular, from Mediterranean diet.

Investigation of the sustained-release mechanism of hydroxypropyl methyl cellulose skeleton type Acipimox tablets

In this study, we investigate the production of hypolipidemic agents in the form of Acipimox sustained-release tablets, using a wet pelleting process. The purpose of this research is to reduce the total intake time for patients and to lower the initial dose in such that the adverse reactions could be reduced. This study adopts the single-factor method and orthogonal experiments by using hydroxypropyl methyl cellulose (HPMC K15M) as the main sustained-release prescription composition. The final prescription is Acipimox 20%, HPMC K15M 26.67%, sodium carboxymethyl cellulose 30%, polyethylene glycol (PEG 6000) 1%, ethyl cellulose 16.6%, lactose 4.67% and magnesium stearate 1%. The dissolution of tablets reached 85.88% in 8 h. The difference in the weight, hardness and friability of the tables met the requirements in the Chinese Pharmacopoeia; to test the stability, a temperature and illumination accelerated test method was used, the results indicate that the Acipimox sustained-release tablets should be sealed and stored in a dark, cool area. A preliminary study on the tablets’ releasing mechanism showed that their release curve fitted the Higuchi model (the formula is Mt /M ∞ = 31.137 t1/2–3.605 (R 2 = 0.9903)). The Acipimox tablets’ release principle is dominated by the diffusion mechanism.

Gemfibrozil treatment in patients with elevated lipoprotein a: a pilot study

OBJECTIVE

This pilot study investigated the efficacy of high-dose gemfibrozil (2400 mg/day) in treating patients with elevated lipoprotein (a) [Lp(a)]. Lp(a) has been shown to be an independent risk factor for the development of coronary heart disease (CHD).

PATIENTS

Eleven patients with serum Lp(a) >/=45 mg/dl participated in this 12-week study. Initially, all patients received oral gemfibrozil 600mg twice daily. At 4-week intervals, the dose was increased by 600mg for patients able to tolerate the increase up to a maximum of 2400 mg/day.

RESULTS

Eight patients completed the study. Three of these patients met the predetermined criterion of a clinically meaningful Lp(a) reduction of 33%. The mean percentage change in Lp(a) was not statistically significant with values of -18.3 +/- 15.4% (p = 0.14, 1-tailed). All patients demonstrated a significant decrease in plasma triglycerides. The mean percentage change was -62.5 +/- 1.8% (p < 0.001, 1-tailed). The mean percentage change in total cholesterol was -12.4 +/- 3.8% (p = 0.007, 1-tailed). Gemfibrozil was considered suspect in five of 16 adverse events reported, but only one of these (dyspepsia) caused withdrawal from the study. For all patients participating in the study no adverse event was characterised as severe.

CONCLUSION

While the small number of patients does not allow any definitive conclusion on effectiveness to be drawn, the results suggest that further randomised studies utilising larger patient numbers appear warranted.

Scientific evidence of interventions using the Mediterranean diet: a systematic review

The Mediterranean Diet has been associated with greater longevity and quality of life in epidemiological studies, the majority being observational. The application of evidence-based medicine to the area of public health nutrition involves the necessity of developing clinical trials and systematic reviews to develop sound recommendations. The purpose of this study was to analyze and review the experimental studies on Mediterranean diet and disease prevention. A systematic review was made and a total of 43 articles corresponding to 35 different experimental studies were selected. Results were analyzed for the effects of the Mediterranean diet on lipoproteins, endothelial resistance, diabetes and antioxidative capacity, cardiovascular diseases, arthritis, cancer, body composition, and psychological function. The Mediterranean diet showed favorable effects on lipoprotein levels, endothelium vasodilatation, insulin resistance, metabolic syndrome, antioxidant capacity, myocardial and cardiovascular mortality, and cancer incidence in obese patients and in those with previous myocardial infarction. Results disclose the mechanisms of the Mediterranean diet in disease prevention, particularly in cardiovascular disease secondary prevention, but also emphasize the need to undertake experimental research and systematic reviews in the areas of primary prevention of cardiovascular disease, hypertension, diabetes, obesity, infectious diseases, age-related cognitive impairment, and cancer, among others. Interventions should use food scores or patterns to ascertain adherence to the Mediterranean diet. Further experimental research is needed to corroborate the benefits of the Mediterranean diet and the underlying mechanisms, and in this sense the methodology of the ongoing PREDIMED study is explained.

Effect of Fenofibrate on Lipoprotein(a) in Hypertriglyceridemic Patients

We investigated the effect of fenofibrate on lipoprotein(a)levels in hypertriglyceridemic patients and the parameters relating to its effect. Patients with a triglyceride level >/=300 mg/dL or with a triglyceride level >/=200 mg/dL and a high density lipoprotein cholesterol level </=40 mg/dL were treated either with 200 mg of fenofibrate(Fenofibrate group, n = 56) or with general measures (Control group,n = 56). Lipid and lipoprotein levels were measured at baseline and 2 months. Baseline lipoprotein(a) levels were negatively correlated with triglyceride (r = 20.30, P = 0.001) and alanine aminotransferase levels (r = 20.24, P = 0.012). Fenofibrate therapy increased lipoprotein(a) level from 9.4 6 10.6 to 15.6 6 17.5 mg/dL (P = 0.000). The more triglyceride levels decreased, the more lipoprotein(a) levels increased in all subjects (r = 20.46, P = 0.000) and in Control (r =20.35, P = 0.008) and Fenofibrate groups (r = 20.35, P = 0.008). Fenofibrate elevated lipoprotein(a) level greater in patients with a normal liver function. When Fenofibrate group was divided into two subgroups according to the degree of percentage change in lipoprotein(a) level, change in triglyceride level and alanine aminotransferase level were independent predictors by forward logistic regression analysis. In summary, fenofibrate therapy increases lipoprotein(a) level,and this elevation is associated with change in triglyceride level and liver function.

Genetics of lipoprotein disorders

The study of lipoprotein metabolism has led to major breakthroughs in the fields of cellular physiology, molecular genetics, and protein chemistry. These advances in basic science are reflected in medicine in the form of improved diagnostic methods and better therapeutic tools. Perhaps the greatest benefit is the improved ability to identify at an early stage patients who are at high risk for atherosclerosis, providing clinicians the opportunity to proceed swiftly with intensive lipid-lowering therapy for the prevention of cardiovascular complications. Recent clinical trials have shown that such an approach is not only cost-effective but saves lives while improving the quality of life. They also emphasize the important role physicians can have in prevention. More than half of patients with premature CAD have a familial form of dyslipoproteinemia. This review of the genetics of atherogenic lipoprotein disorders underscores the importance of identifying major genetic defects. It also stresses the need to take into account multifactorial etiologies and clustering of risk factors, as well as gene-gene and gene-environment interactions in assessing the atherogenic potential of a lipid transport disorder. Table 2 summarizes the key points in the diagnosis, clinical implications, and treatment of the major inherited atherogenic dyslipidemias.

Standardization and clinical management of lipoprotein(a) measurements

The present article proposes personal suggestions to improve determinations and clinical interpretation of results of lipoprotein(a) assays. Methods and procedures for sampling and quantification of the various isoforms of lipoprotein(a) in serum, plasma and urine are reviewed with the aim of improving the reliability and reproducibility of results and reinforcing the clinical utility of lipoprotein(a) measurements.