Association of lipoprotein(a) levels and apolipoprotein(a) phenotypes with coronary artery disease in Type 2 diabetic patients and in non-diabetic subjects.

AIMS: We investigated whether in Type 2 diabetic patients lipoprotein(a) (Lp(a)) levels and apolipoprotein(a) (apo(a)) polymorphism are associated with angiographically documented coronary artery disease (CAD). We also examined whether there are differences in the distributions of Lp(a) levels and apo(a) phenotypes between CAD patients with and without diabetes. METHODS: A hundred and seven diabetic patients with CAD, 274 diabetic patients without CAD, 201 non-diabetic patients with CAD, and 358 controls were enrolled. RESULTS: Diabetic patients with CAD showed Lp(a) levels (21.2 +/- 17.7 vs. 15.1 +/- 17.8 mg/dl; P = 0.0018) and a percentage of subjects with at least one apo(a) isoform of low molecular weight (MW) (67.2% vs. 27.7%; P = 0.0000) significantly greater than diabetic patients without CAD. Multivariate analysis showed that in diabetic patients Lp(a) levels and apo(a) phenotypes were significantly associated with CAD; odds ratios (ORs) of high Lp(a) levels for CAD were 2.17 (1.28-3.66), while ORs of the presence of at least one apo(a) isoform of low MW were 5.35 (3.30-8.60). Lp(a) levels (30.2 +/- 23.7 vs. 21.2 +/- 17.7 mg/dl; P = 0.0005) and the percentage of subjects with at least one apo(a) isoform of low MW (87.0% vs. 67.2%; P = 0.0001) were significantly higher in CAD patients without than in those with diabetes. CONCLUSIONS: Our data suggest that Lp(a) levels and apo(a) phenotypes are independently associated with CAD in Type 2 diabetic patients; thus both these parameters may be helpful in selecting diabetic subjects at high genetic cardiovascular risk. However, Lp(a) levels and apo(a) polymorphism seem to be cardiovascular risk factors less important in diabetic than in non-diabetic subjects. Diabet. Med. 18, 589-594 (2001)

[Is there a role for clinical medicine in the threshold of the third millennium?]. / Resta un ruolo per la medicina clinica alle soglie del terzo millennio?

The technological advances of the last decades favoured remarkable successes in the study and the treatment of diseases. On the other hand, it risks to take the physician away from the interpersonal relationship with the patient. This kind of relation should be grounded, most of all, on hearing and dialogue, on the practice of observation, semeiologic interpretation and clinical reasoning, as well as on fixed parameters, laboratory tests and instrumental investigation. To reduce this kind of risk and to return the physician of the twenty-first century all the peculiarities of the bonus sanandi peritus, the author hopes that medicine is going to become a "medicine of the person" again: a medicine that will always prefer the therapeutical alliance and the clinical mode of diagnostic procedures.

Severe hypercalcemia and systemic lupus erythematosus.

A rare case of severe hypercalcemia strongly associated with Systemic Lupus Erythematosus (SLE) is reported. On admission, a young woman showed severe hypercalcemia and photosensitivity. Criteria for diagnosis of SLE were not sufficient. All causes, common and uncommon, of hypercalcemia were excluded. Radiographs of the skeleton were normal. One year later diagnosis of SLE was evident. In addition, diffuse and severe osteopenia and chest deformities had occurred. The treatment of SLE normalized persistently calcemia. Mild elevation of calcium levels occurred during flares of SLE. It has been hypothesized that hypercalcemia in patients with SLE could be caused by the presence of stimulatory anti-PTH receptor antibodies. This case report suggests that in patients with severe hypercalcemia associated with SLE early diagnosis and treatment of SLE may prevent bone loss. In these patients the prevention of severe bone damage is very important. Indeed, severe osteopenia may favour skeletal deformities and fractures; in addition it may represent a serious obstacle in using adequate doses of glucocorticoids for treatment of SLE.

Impaired diastolic function in active rheumatoid arthritis. Relationship with disease duration.

OBJECTIVE: Using digitized M-mode and Doppler echocardiography, we evaluated left ventricular (LV) function in 54 patients (43 women and 11 men; mean age 50 years) suffering from active rheumatoid arthritis (RA) without obvious cardiovascular disease, and compared them with 54 age- and sex-matched normal subjects. RESULTS: No differences were found in LV end-diastolic diameter, systolic function and parietal thickness between the patients and controls. However, a significant reduction in various indexes of LV diastolic function was found, including E/A (ratio of early to late filling waves of mitral inflow Doppler) and the peak lengthening rate of the LV diameter (an index of LV relaxation evaluated by M-mode echocardiography). The former was correlated with patient age and was independent of disease duration, while the latter was more markedly correlated with disease duration than with patient age. CONCLUSION: The relationship between diastolic impairment and disease duration in active RA may open new perspectives in the study of RA-associated cardiovascular disease.

Genetics and cardiovascular risk: a role for apolipoprotein(a) polymorphism.

Apolipoprotein(a) [apo(a)] is the specific apolipoprotein of lipoprotein(a) [Lp(a)], a recognized cardiovascular risk factor. Apo(a) is characterized by a high genetic polymorphism with at least 34 isoforms in plasma. Recent studies have shown that in atherothrombosis apo(a) polymorphism could play a role independent of Lp(a) levels. In particular, apo(a) phenotypes seem to have their highest predictive value for coronary heart disease, when apo(a) isoforms are detected by high resolution phenotyping methods and when an adequate operative cut-off of apo(a) polymorphism is used. A strong association between apo(a) phenotypes and coronary heart disease has been also found in hypertensive, diabetic, and uremic patients. Moreover, apo(a) phenotypes seem to correlate well with the severity of coronary atherosclerosis and the age of clinical onset of coronary heart disease. These studies suggest that apo(a) polymorphism may have a great clinical usefulness in a primary prevention setting, since apo(a) phenotypes could be used together with Lp(a) levels as strong genetic predictors of atherothrombosis. The analysis of apo(a) polymorphism appears to be particularly useful in healthy subjects with a family history of atherothrombotic diseases, in patients with diseases at high cardiovascular risk (diabetes, hypertension, hypercholesterolemia) and in subjects with conditions modifying Lp(a) levels.

Association between apolipoprotein(a) phenotypes and coronary heart disease at a young age.

OBJECTIVES: The purpose of this study was to investigate lipoprotein(a) [Lp(a)] levels and apolipoprotein(a) [apo(a)] phenotypes in relation to age of onset of coronary heart disease (CHD). BACKGROUND: Although Lp(a) levels have been extensively analyzed in relation to age of CHD, apo(a) phenotypes have not. METHODS: Three hundred and thirty-five consecutive CHD patients were enrolled and grouped according to their age of CHD onset (<45 years; 45 to 54 years; > or = 55 years). RESULTS: In each patient group Lp(a) levels were higher than in an age-matched control group, but among the patient groups no differences in Lp(a) levels were observed. Apolipoprotein(a) phenotype distributions showed significant differences between patients and age-matched control subjects. Among the patient groups the difference in percentage of subjects with two apo(a) isoforms of low molecular weight (MW) was highly significant (p < 0.001). Multivariate analysis showed that apo(a) phenotypes were the best predictors of early CHD (p < 0.000001). The age-specific odds ratios (ORs) of the presence of at least one apo(a) isoform of low MW for CHD declined with age; in particular apo(a) phenotypes had their highest predictive value in younger persons (OR: 14.62). The OR for the presence of two isoforms of low MW/presence of only isoforms of high MW was 40.88 in the younger age group, 27.17 in age group of 45 to 54 years and 15.83 in the older age group. CONCLUSIONS: The present article reports the first evidence of a strong independent association of apo(a) phenotypes with the age of onset of CHD. Thus, if our data are confirmed by larger studies, apo(a) phenotypes might be used together with Lp(a) levels as powerful genetic markers in assessing the actual risk of developing CHD at a young age.

Plasminogen activator inhibitor-1 and carotid intima-media thickening in patients with newly detected primary hypertension.

OBJECTIVE: To investigate the correlation between ultrasonographically evaluated intima-media thickness (IMT) of common carotid artery (CCA) and cardiovascular risk factors for subjects with newly detected, uncomplicated and untreated primary hypertension. METHODS: The study population consisted of 200 subjects (123 men and 77 women, aged 46+/-7.5 years). Blood pressure was measured in the clinical setting and by 24 h noninvasive ambulatory monitoring. Fasting levels of blood glucose, plasma lipids and lipoproteins, fibrinogen and plasminogen activator inhibitor (PAI)-1 were measured. Ultrasound examination included measurement of far-wall intima-media complex of CCA and morphologic evaluation of occurrence of plaques in carotid and femoral bifurcations. RESULTS: The prevalence of greater than normal IMT (mean IMT > or =0.80 mm) was 22%. Significant univariate correlations to the dichotomy between normal and greater than normal mean IMT were detected for age, smoking, level of LDL cholesterol, level of PAI-1 and total ultrasonographic score. Multivariate logistic regression analysis confirmed the associations between greater than normal mean IMT and plasma concentrations of LDL cholesterol and PAI-1 as well as total ultrasonographic score. CONCLUSION: Greater than normal IMT of CCA was more strictly related to other cardiovascular risk factors than it was to blood pressure and was strongly associated with the occurrence of atherosclerotic plaques in carotid and femoral arteries. The role of PAI-1 in intima-media thickening that is emerging suggests that fibrinolytic balance is an important determinant of vessel-wall homeostasis in hypertensive patients.

Apolipoprotein(a) phenotypes and their predictive value for coronary heart disease: identification of an operative cut-off of apolipoprotein(a) polymorphism.

BACKGROUND: Apolipoprotein(a) isoforms of low-molecular weight are associated with coronary heart disease. However, because of the high number of apolipoprotein(a) isoforms, it is difficult to assess the cardiovascular risk linked to the apolipoprotein(a) gene of a subject; indeed a cut-off of apolipoprotein(a) polymorphism has not been established. The aim of this investigation was to identify an 'operative' cut-off that discriminates apolipoprotein(a) isoforms associated with high genetic risk for coronary heart disease. METHODS: Two hundred and fifty-one patients with coronary heart disease and 284 controls were recruited. Apolipoprotein(a) isoforms were detected using a high-resolution phenotyping method. RESULTS: Twenty-seven apolipoprotein(a) isoforms with apparent molecular weight varying from 280 to 820 kDa were identified. Several cut-offs of apolipoprotein(a) polymorphism were used in order to compare the frequencies of apolipoprotein(a) isoforms of low and high molecular weight between patients and controls: the cut-off between 640 and 655 kDa had the highest chi 2 (130.40). Even when possible differences in apolipoprotein(a) phenotypes (subjects with at least one isoform of low molecular weight and subjects with only isoforms of high molecular weight) were assessed, the same cut-off showed the highest chi 2 (122.47). Multivariate analysis showed that apolipoprotein (a) isoforms had the greatest predictive value for coronary heart disease (F value = 107.0720), when the cut-off between 640 and 655 kDa was used. CONCLUSIONS: The cut-off between 640 and 655 kDa appears to be the most efficient in identifying subjects at high cardiovascular risk linked to apolipoprotein(a) gene, since this cut-off discriminates apolipoprotein(a) isoforms expressing a greater risk for coronary heart disease.

Apolipoprotein(a) phenotypes as genetic markers of coronary atherosclerosis severity.

We investigated Lp(a) levels and apo(a) polymorphism in relation to the severity of coronary artery disease, expressed both by the number of coronary arteries stenosed and three different coronary scoring systems. In a sample of 267 patients with coronary artery disease, a Mono-, Bi- or Multi-vessel coronary stenosis was documented by angiography. Twenty-five apo(a) isoforms were detected by a high resolution phenotyping method. Lp(a) levels did not show any differences among subgroups of patients. Both the percentage of apo(a) isoforms of low molecular weight (<655 kDa) (P=0.00015) and the percentage of subjects with at least one apo(a) isoform of low molecular weight (P=0.00027) were significantly correlated with increasing number of coronary vessels stenosed. In multivariate analysis, only apo(a) isoforms of low molecular weight were predictors of coronary atherosclerosis severity, when we used as the dependent variable both the '1-2-multi-vessels' categorization (P=0.000067) and the Gensini (P=0.008767), or Green Lane (P= 0.000001) or Dahlen (P=0.000102) coronary scoring system. Our data show that apo(a) isoforms of low molecular weight are associated with a greater severity of coronary atherosclerosis. If these data are confirmed by prospective studies, apo(a) phenotypes might be used as genetic markers of a greater severity of coronary atherosclerotic lesions.

Lipoprotein(a) levels and apolipoprotein(a) polymorphism in type 1 diabetes mellitus: relationships to microvascular and neurological complications.

To investigate plasma concentrations of lipoprotein(a) [Lp(a)] and apolipoprotein(a) [apo(a)] polymorphism in relation to the presence of microvascular and neurological complications in type 1 diabetes mellitus, 118 young diabetic patients and 127 age-matched controls were recruited. Lp(a) levels were higher in patients than in controls, but the apo(a) isoforms distribution did not differ between the two groups [higher prevalence of isoforms of high relative molecular mass (RMM) in both groups]. Microalbuminuric patients had Lp(a) levels significantly greater than normoalbuminuric patients, and normoalbuminuric patients showed higher Lp(a) levels than controls. Patients with retinopathy or neuropathy showed similar Lp(a) levels to those without retinopathy or neuropathy. No differences in apo(a) isoforms frequencies were observed between subgroups with and without complications (higher prevalence of isoforms of high RMM in every subgroup). However, among patients with retinopathy, those with proliferative retinopathy had higher Lp(a) levels and a different apo(a) isoforms distribution (higher prevalence of isoforms of low RMM) than those with non-proliferative and background retinopathy (higher prevalence of isoforms of high RMM). Our data suggest that young type 1 diabetic patients without microalbuminuria have Lp(a) levels higher than healthy subjects of the same age. Lp(a) levels are further increased in microalbuminuric patients. High Lp(a) levels and apo(a) isoforms of low RMM seem to be associated with the presence of proliferative retinopathy, but have no relation to neuropathy.

Influence of type of surgery on the occurrence of parasympathetic reinnervation after cardiac transplantation.

BACKGROUND: Cardiac autonomic reinnervation after human cardiac transplantation has been demonstrated frequently but to date only for sympathetic efferents. Standard surgical techniques leave many parasympathetic branches intact in the original atria and thus with less stimulus to reinnervate the donor atria. METHODS AND RESULTS: We used changes in the RR-interval power spectrum induced by sinusoidal modulation of arterial baroreceptors by neck suction at different frequencies to detect both parasympathetic and sympathetic reinnervation in 79 subjects with "standard" and 10 "bicaval" heart transplants. In 24 subjects (17 standard and 7 bicaval), the protocol was repeated 6 and 11 months after transplantation. Neck suction at 0.20 Hz produced a component at 0.20 Hz in the RR-interval spectrum not due to respiration (fixed at 0.25 Hz), which suggested parasympathetic reinnervation, in 4 of 10 bicaval but in only 2 of 79 standard transplant subjects (whose recipient atria underwent >50% resection to remove scars of previous interventions), P<.001. In only 1 (bicaval) transplant subject was parasympathetic reinnervation present 6 months after transplantation (confirmed 3 months later); in 4 subjects, it was absent at 6 months but appeared after 11 months after transplantation. Atropine (0.04 mg/kg i.v.) abolished the response to fast (0.20 Hz) and reduced that to slow stimulation, confirming the presence of parasympathetic reinnervation (4 subjects). CONCLUSIONS: Parasympathetic reinnervation depends on the surgical technique: because bicaval surgery cuts all sympathetic and parasympathetic nerves, regeneration might be stimulated similarly in both branches. Standard surgery cuts only approximately 50% of sympathetic fibers; most recipient parasympathetic axons remain intact, hence their regeneration might not be stimulated.

In search of biological markers of high-risk carotid artery atherosclerotic plaque: enhanced LDL oxidation.

The oxidation of low density lipoprotein (LDL) is a key event in the development and progression of atherosclerosis because it generates molecular epitopes that are more atherogenic than parent LDL. We found previously that patients with carotid atherosclerosis have a significantly higher titer of autoantibodies against oxidatively modified LDL than normal subjects. The aim of this study is to correlate biological markers of in vivo LDL oxidation with the degree of carotid stenosis and of plaque ulceration (PU) in a series of patients undergoing carotid endoarteriectomy (CEA). Ninety-four consecutive patients (68M and 26F, aged 67.3 +/- 8.2 years) who underwent CEA at our institution between June 1993 and January 1994 were included in the study. The degree of carotid stenosis and the presence and extent of PU were correlated with the level of autoantibodies (IgG) against oxidatively modified LDL (Cu++-oxidized [oxLDL] or malondialdehyde derivatized LDL [MDA-LDL]), that consistently mirrors the occurrence of oxidative modifications in vivo. A statistically significant correlation (r = 0.23, p = 0.039) was found between the degree of carotid stenosis and antiMDA-LDL specific ratio (a parameter that describes the specificity of LDL towards other proteins as target for oxidative modification). A statistically significant correlation was also found between the PU score and antioxLDL IgG (r = 0.32, p = 0.011), antiMDA-LDL IgG (r = 0.25, p = 0.045) and antiMDA-LDL IgG specific ratio (r = 0.38, p = 0.002). None of the classical biochemical parameters (total, LDL and HDL cholesterol and triglycerides) correlated with the above-mentioned plaque characteristics. The results shown, support the use of biological markers of in vivo LDL oxidation (antioxidatively modified LDL autoantibody titers) to evaluate the clinical setting of high-risk carotid atherosclerosis both in screening and in follow-up studies.

Association of lipoprotein(a) levels and apolipoprotein(a) phenotypes with coronary heart disease in patients with essential hypertension.

BACKGROUND: Besides hypertension, several cardiovascular risk factors can play a role in the development of coronary heart disease (CHD) in hypertensive patients. Lipoprotein(a) [Lp(a)] is an important and independent cardiovascular risk factor, but its role in the development of CHD in hypertensives has not been studied. OBJECTIVE: To investigate whether or not Lp(a) levels and isoforms of apolipoprotein(a) [apo(a)] are predictors of CHD in patients with essential hypertension. METHODS: Lp(a) levels and apo(a) polymorphism were evaluated in 249 patients with essential hypertension, in 142 non-hypertensive patients with CHD and in 264 healthy controls. RESULTS: Hypertensives with CHD (n = 61) had Lp(a) levels [19 (range 0.5-73.5) versus 7 mg/dl (range 0-83.5), P < 0.001] and a percentage of apo(a) isoforms of low (< 655 kDa) relative molecular mass (RMM, 59.2 versus 25.9%, P < 0.001) higher than did those without CHD (n = 188). Moreover, there were more subjects with at least one apo(a) isoform of low RMM in the subgroup of patients with CHD than there were in that of those without CHD (80.3 versus 30.8%, P< 0.001). Lp(a) levels and apo(a) polymorphism did not differ significantly between hypertensive and non-hypertensive patients with CHD. Stepwise regression analysis indicated that high Lp(a) levels (P= 0.002073) and particularly the presence of at least one apo(a) isoform of low RMM (P < 0.000001) are strong predictors of CHD in hypertensive patients. CONCLUSIONS: Our data show that high Lp(a) levels and the presence of at least one apo(a) isoform of low RMM are strong and independent genetic risk factors for CHD in hypertensive patients. These findings suggest that Lp(a) and apo(a) isoforms should be assessed together with other cardiovascular risk factors to establish the overall CHD risk status of each hypertensive patient

Lipoprotein(a) plasma concentrations, apolipoprotein (a) polymorphism and family history of coronary heart disease in patients with essential hypertension.

AIM: The purpose of the study was to investigate lipoprotein (a) (Lp(a)) levels and apolipoprotein (a) (apo(a)) phenotypes, and their relationship with a family history of coronary heart disease (CHD) in patients with essential hypertension (EH). METHODS: One hundred and eight newly diagnosed patients with mild to moderate EH and 159 controls were studied. Lp(a) levels were determined with an ELISA method. Apo(a) isoforms were identified by a capillary immunoblotting technique. RESULTS: Lp(a) levels and frequency distribution of apo(a) isoforms did not show significant differences between patients and controls. Lp(a) levels in hypertensives with a family history of CHD were significantly higher than in those without a family history of CHD (P < 0.01). Hypertensives with a family history of CHD showed significantly different frequencies of apo(a) isoforms to those without a family history of CHD (P < 0.05). In EH patients with a family history of CHD, apo(a) isoforms of low molecular weight (MW) had a higher prevalence (62.6%), while in hypertensives without a family history of CHD, apo(a) isoforms of high MW were prevalent (81.6%); the difference between the two subgroups was significant (P < 0.001). Multivariate analysis showed that both Lp(a) levels and apo(a) isoforms of low MW are significant variables in distinguishing between the subgroups. CONCLUSIONS: Lp(a) levels and apo(a) phenotypes do not differ between hypertensives and controls. High Lp(a) levels and apo(a) isoforms of low MW are strongly associated with a family history of CHD in hypertensives. The quantification of Lp(a) levels and the characterization of apo(a) phenotypes may be used for assessment of familial predisposition to CHD in hypertensives.

Determinants of heart rate variability in heart transplanted subjects during physical exercise.

Respiratory sinus arrhythmia has been described in heart transplanted subjects. In order to investigate the mechanisms involved in the generation of this condition in the transplanted heart and its evolution after surgery, graded exercise was performed (0-75 W in 25 W steps) on a cycle ergometer by 41 subjects (mean age 44 years) who had undergone heart transplantation 28 months (range 3-60) earlier and by six age matched-control subjects. R-R interval, respiratory signal, O2 consumption (VO2) and CO2 production (VCO2) were measured. Respiratory sinus arrhythmia was assessed by the autoregressive power spectrum of the R-R interval and respiration. All subjects reached the anaerobic threshold (heart transplants: 60% at 50 W, 40% at 75 W Controls: 150 W). In control subjects, the respiratory sinus arrhythmia was higher than in heart transplanted subjects (5.80 +/- 0.30 vs 1.45 +/- 0.16 1n ms2) and it decreased significantly (4.66 +/- 0.30 1n ms2, P < 0.05) during exercise, despite the increase in breathing rate and depth. When, the group of heart transplanted subjects was considered as a whole, respiratory sinus arrhythmia was found to be present in all conditions. It significantly increased at 25 W (from 1.45 +/- 0.16 to 2.00 +/- 0.17 1n ms2, P < 0.01), then significantly fell below baseline during recovery (to 0.97 +/- 0.23 1n ms2, P < 0.01). Multiple regression analysis showed that a linear combination of heart rate (inverse correlation) and VO2 (direct correlation) together with months having passed since transplantation surgery, could explain the observed changes in heart rate during exercise (multiple regression: r = 0.658, P < 0.0001). In five long-term transplanted subjects, non respiratory-related low frequency (0.1 Hz) waves were present on the R-R spectrum, but respiratory sinus arrhythmia is also present in the recently transplanted heart and depends on the opposing effects of ventilation and heart rate. In a few cases, sympathetic modulation (re-innervation) could not be excluded.