Cardiovascular disease and Lp(a) in the adult population and in the elderly: the Brisighella study.

Objective: The aim of this study was to evaluate the distribution of the concentrations of lipoprotein(a) [Lp(a)] in a free-living population, that of Brisighella, and to study the degree of association with cardiovascular disease (CVD) and other associated risk factors. The Brisighella study is included in the framework of observational and interventional longitudinal studies; it began in 1972 to monitor the spontaneous trend of the risk factors for atherosclerosis and to evaluate the incidence of CVD in a rural population.

Methods: The studies were carried out on 1319 subjects, 627 males and 692 females, aged over 14 years, of which 134 men and 113 women were geriatric (age > 64 years); the data are relative to the control of the population in 1988. The following were evaluated for each subject: (a) weight and height; (b) hematological parameters; (c) clinical events; (d) presence of other concomitant diseases. For the dosage of the hematological parameters, enzymatic-colorimetric parameters were used (total and HDL cholesterol, triglycerides, glycemia and uremia), radial immunodiffusion and immunoturbidimetry (apoAI and B), ELISA-sandwich immunoenzymatic method (Lp(a)). All the methods used are standardized and internal and external laboratory quality control was carried out. The data collected were analyzed with the program STATGRAPHIC VERSION 6.0; the mean, the standard deviation and the median were calculated for all the variables. The frequency tables, distribution curves (approximation estimates with the chi 2 test), and single and multiple regression were also calculated. A value of p < 0.01 was taken as the level of significance.

Results: The distribution of Lp(a) in the control population and in subjects with CVD was substantially the same for both sexes; the differences between the mean levels of Lp(a) were not statistically significant (18.5 mg/dl vs 20.09 mg/dl for men and 19.98 mg/dl vs 22.78 mg/dl for women). The same also applies to the elderly population (18.81 mg/dl vs 23.31 in the men and 21.13 mg/dl vs 21.47 mg/dl in the women). No significant variations were observed in the mean values of Lp(a) even when other risk factors were taken into consideration, such as hypertension, obesity and diabetes. Finally, multiple regression analysis did not show any correlation between Lp(a) levels and those of the other hematological parameters.

Conclusions: In this transversal study, we found no evidence to suggest that Lp(a) can be considered and independent and predictive risk factor for CVD. It would therefore seem that in the population of Brisighella the levels of Lp(a) are "causally" distributed, without any correlation with the presence of cardiovascular events or with hypertension, diabetes or obesity in both sexes.