Generation of induced pluripotent stem cells (CSSi017-A)(12862) from an ALS patient carrying a repeat expansion in the C9orf72 gene.

Genetic expansions of the hexanucleotide repeats (GGGGCC) in the C9orf72 gene appear in approximately 40% of patients with familial ALS and 7% of patients with sporadic ALS in the European population, making this mutation one of the most prevalent genetic mutations in ALS. Here, we generated a human induced pluripotent stem cell (hiPSC) line from the dermal fibroblasts of a patient carrying a 56-repeat expansion in an ALS disease-causing allele of C9orf72. These iPSCs showed stable amplification in vitro with normal karyotype and high expression of pluripotent markers and differentiated spontaneously in vivo into three germ layers.

Tuberculosis of superficial lymph nodes, a not so rare event to consider in diagnosis. A case in an elderly male.

Tuberculosis (TB) is still one of the most frequent infectious diseases worldwide. Until the 1990s, Western European countries showed a low frequency of TB infection, but the rise of immigration has led to a rapid increase in its occurrence. In the elderly, TB is emerging as a significant health problem (age-related decline of the cell-mediated immunity, associated illnesses, use of immunosuppressive drugs, malnutrition, poor life conditions), although its detection and diagnosis is not easy also considering its subclinical presentation. Almost 70% of all TB infections in Italy are found in the lungs; 50% of the extrapulmonary infections affect lymph nodes. Due to the low incidence of superficial tuberculous lymphadenitis without pulmonary manifestations, the possibility of a TB aetiology is often not taken into consideration in the differential diagnosis of lymphadenopathy, resulting in significant delay of appropriate treatment. Herein, we describe the case of a 78-year-old male with nocturnal fever, weakness, night sweats, loss of weight and decay in general condition. The patient had a past medical history of prostate adenocarcinoma treated with hormone therapy. The past medical history in association with clinical findings and laboratory data (anaemia, high titers of fibrinogen and reactive C-protein) led to the suspect of metastatic adenocarcinoma. Only histological and molecular biology findings allowed us to make a correct diagnosis of TB.

Diabetes, prediabetes and cancer mortality.

AIMS/HYPOTHESIS: We aimed to investigate the risk of cancer mortality in relation to the glucose tolerance status classified according to the 2 h OGTT. METHODS: Data from 17 European population-based or occupational cohorts involved in the DECODE study comprising 26,460 men and 18,195 women aged 25-90 years were collaboratively analysed. The cohorts were recruited between 1966 and 2004 and followed for 5.9 to 36.8 years. Cox proportional hazards analysis with adjustment for cohort, age, BMI, total cholesterol, blood pressure and smoking status was used to estimate HRs for cancer mortality. RESULTS: Compared with people in the normal glucose category, multivariable adjusted HRs (95% CI) for cancer mortality were 1.13 (1.00, 1.28), 1.27 (1.02, 1.57) and 1.71 (1.35, 2.17) in men with prediabetes, previously undiagnosed diabetes and known diabetes, respectively; in women they were 1.11 (0.94, 1.30), 1.31 (1.00, 1.70) and 1.43 (1.01, 2.02), respectively. Significant increases in deaths from cancer of the stomach, colon-rectum and liver in men with prediabetes and diabetes, and deaths from cancers of the liver and pancreas in women with diabetes were also observed. In individuals without known diabetes, the HR (95% CI) for cancer mortality corresponding to a one standard deviation increase in fasting plasma glucose was 1.06 (1.02, 1.09) and in 2 h plasma glucose was 1.07 (1.03, 1.11). CONCLUSIONS/INTERPRETATION: Diabetes and prediabetes were associated with an increased risk of cancer death, particularly death from liver cancer. Mortality from all cancers rose linearly with increasing glucose concentrations.

Valproate-induced delirium in a demented patient.

In this study we report a case of valproate-induced delirium in a patient affected with Alzheimer's disease (AD). A 75-year-old woman with AD presented moderate cognitive impairment associated to behavioral disorders, characterized by aggression, agitation, severe insomnia. She was treated with galantamine, promazine, acetylsalicylic acid and pantoprazole. Since behavioral disorders worsened more and more, home neurological consultation was asked. The neurologist prescribed a mood stabilizer, sodium valproate 500 mg daily for the first week and then, twice a day and stopped promazine. After an apparent initial benefit, about 16 days later, patient suddenly developed hyperactive delirium. It was characterized by worsening of insomnia and agitation, severe confusion, delusions, visual hallucinations alternated to sedation. She became progressively unable to walk and completely dependent in daily living activities. An urgent geriatric consultation was performed at patient's home; physical examination showed mild dehydration, normal blood pressure. Oxygen saturation and electrocardiogram were normal. Sodium valproate was immediately stopped and rehydration was performed. The patient was admitted to a Geriatric Unit, where organic and metabolic damages were excluded. During the hospital stay the patient was agitated, aggressive, confused; intramuscular haloperidol 5mg and saline intravenous infusion 1500 cc daily were performed, they were partly successful. Three days after she was discharged and continued treatment with oral haloperidol 5mg daily. One week later the patient recovered and she is at present healthy. This is a case report of valproate-induced delirium. The Naranjo scale scored 7, classifying this drug-related event as probable. The present case report suggests the need for minimizing the use of psychoactive drugs in elderly demented patients, whether possible; age-related changes in pharmacokinetics and pharmacodynamics suggest the opportunity of a careful evaluation and a slow titration of treatments in these patients.

Blood lipid levels in relation to glucose status in European men and women without a prior history of diabetes: the DECODE Study.

OBJECTIVE: Dyslipidaemia is present not only in diabetic but also in prediabetic subjects. The purpose of this study is to investigate the relationship between lipid and glucose levels in a large European population without a prior history of diabetes. RESEARCH DESIGN AND METHODS: Data from the population-based studies of 8960 men and 10,516 women aged 35-74 years representing 15 cohorts in 8 European countries were jointly analyzed. Multivariate adjusted linear regression analyses with standardized coefficients (beta) were performed to estimate the relationship between lipid and plasma glucose. RESULTS: In subjects without a prior history of diabetes, positive relationships were shown between fasting plasma glucose (FPG) and total cholesterol (TC) (beta=0.06 and 0.03, respectively for men and women, p<0.01), triglycerides (TG) (beta=0.14 and 0.12, p<0.001), non-high-density lipoprotein cholesterol (non-HDL-C) (beta=0.06 and 0.03, p<0.01) and TC to HDL ratio (beta=0.06 and 0.05, p<0.001) but a negative trend between FPG and HDL-C (beta=-0.02, p>0.05 in men and beta=-0.03, p<0.05 in women). The relationship between lipid and 2-h plasma glucose (2hPG) followed a similar pattern as that for FPG, except that TC was not increased and HDL-C was reduced in both sexes in subjects with impaired glucose tolerance (IGT). CONCLUSIONS: For cardiovascular prevention, the different lipid patterns between impaired fasting glucose (IFG) and IGT may deserve further attention to evaluate the combined risks of dyslipidaemia and elevated glucose levels below the diagnostic threshold of diabetes.

Correlation of serum IGF-I and IGFBP-1 and -3 to cardiovascular risk indicators and early carotid atherosclerosis in healthy middle-aged men.

OBJECTIVES: IGF-I, IGFBP-1 and IGFBP-3 are putative mediators in cardiovascular disease. The present study examined (i) the correlations of circulating IGF-I, IGFBP-1 and IGFBP-3 to established cardiovascular risk factors and signs of early atherosclerosis as reflected by ultrasound measurement of common carotid intima-media thickness (IMT), and (ii) whether serum concentrations of these analytes are modulated during alimentary lipaemia. DESIGN: Cross-sectional clinical study. PATIENTS: A biobank and clinical database based on 96 healthy Caucasian men, aged 50 years, with an apolipoprotein (apo) E3/E3 genotype, who had originally undergone investigations of postprandial lipoprotein metabolism was used for the study. MEASUREMENTS: Total IGF-I, IGFBP-1 and IGFBP-3 were determined in serum by radioimmunoassay (RIA). Free IGF-I was measured by a commercial two-site immunoradiometric assay (IRMA). RESULTS: In multivariate analyses, fasting serum free IGF-I correlated inversely with IMT and accounted for 5% of the variation in multiple R(2). When fasting serum IGFBP-1 was entered in the models instead of IGF-I, IGFBP-1 correlated positively with IMT and accounted for 6% of the variation in IMT. IGFBP-3 and total IGF-I were unrelated to IMT. There were no associations between free IGF-I and cardiovascular risk factors, whereas IGFBP-1 behaved like a component of the insulin resistance syndrome. Serum free IGF-I increased and IGFBP-1 decreased postprandially. CONCLUSION: The data indicate that serum free IGF-I and IGFBP-1 are implicated in early atherosclerosis.

[Evaluation of thyroid function in a group of over-eighty year-old people]. / Valutazione della funzionalità tiroidea in un gruppo di ultraottantenni.

AIM: A number of studies has shown that during aging thyroid presents some structural changes, whilst no data agree about secretory activity. The aim of the present study was to evaluate thyroid function in a group of healthy over-80 years old people vs a group of young subjects. METHODS: This study was performed on 48 old people, 33 women (68.75%) and 15 men (31.25%), mean age 86.38+/-5.20 years old and 43 young subjects, mean age 33.35+/-3.75 years old; all of them were euthyroid and were not affected with any acute or chronic diseases and did not take any drugs which could interfere with thyroid function. A blood sample was taken from each patient, for dosing TT3, TT4, FT3, FT4, TSH, TgAb, TPOAb. RESULTS: The results of the present study show low serum levels of TT3 in healthy over-80 year old people compared to young people, even if serum levels of TT4, FT3, FT4, TSH have no significant changes. CONCLUSIONS: Functional reduction in thyroid activity during aging has not to be considered responsible for senile involution; it is more appropriate to define it as the expression of a metabolic slow down in the elderly.

[Falls in the elderly]. / Le cadute nell'anziano.

Falls are the main causes of accidental death and disability in elderly people, since they may especially cause hip fractures and a number of related complications. Available incidence estimates are surely in defect, because falls are often omitted both by patients, their family and caregivers. Risk factors may be classified in intrinsic and extrinsic; the former include muscular and osteoarticular diseases or other favouring conditions, whilst the latter include environmental or iatrogenic factors, such as drugs or alcohol consumption. Extrinsic factors may be rapidly modified in the elderly and thus prevented. In fact, prevention of falls is the main intervention of geriatrist, both at patient's home and if patient is hospitalized. In order to reduce the risk of falls, it is sometimes sufficient to stop a treatment or to reduce the doses of drugs causing sedation or orthostatic hypotension, to avoid if possible, the use of sedative-hypnotics, to use non-pharmacological methods for treating insomnia. The introduction of the necessary changes in the environment, the promotion of physical activity, the individuation of the subjects with a high risk of falls and the use of hip protectors are useful means for preventing falls and avoiding their harmful consequences.

Human evidence that the apolipoprotein a-II gene is implicated in visceral fat accumulation and metabolism of triglyceride-rich lipoproteins.

BACKGROUND: Apolipoprotein (apo) A-II is a major structural protein of plasma HDLs, but little is known regarding its functions. METHODS AND RESULTS: To investigate the physiological role of apoA-II in humans, we screened the promoter region of the apoA-II gene for a functional polymorphism and used this polymorphism as a tool in association studies. A common, functional polymorphism in the promoter region of the apoA-II gene, a T to C substitution at position -265, was found. Electrophoretic mobility shift assays demonstrated that the -265T/C polymorphism influences the binding of nuclear proteins, whereas transient transfection studies in human hepatoma cells showed a reduced basal rate of transcription of the -265C allele compared with the -265T allele. The -265C allele was associated with decreased plasma apoA-II concentration and decreased waist circumference in healthy 50-year-old men. In addition, oral fat tolerance tests provided evidence that the -265C allele enhances postprandial metabolism of large VLDLs. CONCLUSIONS: ApoA-II appears to promote visceral fat accumulation and impair metabolism of large VLDLs.

The Q/E27 polymorphism in the beta2-adrenoceptor gene is associated with increased body weight and dyslipoproteinaemia involving triglyceride-rich lipoproteins.

OBJECTIVES: To investigate whether a substitution of glutamine by glutamic acid at amino acid position 27 (Q/E27) and an arginine to glycine transition at amino acid 16 (R/G16) in the beta2-adrenoceptor gene are associated with lipid and lipoprotein disturbances and/or increased body weight in men. DESIGN: Population-based study. SETTING: Department of medicine at a university hospital. SUBJECTS: A total of 180 healthy men, aged 30-45 years, were recruited at random from a register containing all permanent residents in Stockholm County (response rate of 70%). MAIN OUTCOME MEASURES: Frequency of beta2-adrenoceptor genotypes and alleles in relation to plasma lipid and lipoprotein levels and body mass index. RESULTS: Individuals carrying the E27 allele and/or the G16 allele had significantly higher body mass index (BMI). Furthermore, carriers of the E27 allele had significantly higher plasma concentrations of cholesterol, triglycerides, VLDL cholesterol and VLDL triglycerides than did subjects homozygous for the Q allele. CONCLUSION: The E27 allele of the beta2-adrenoceptor gene is associated with slightly to moderately elevated BMI and dyslipoproteinaemia involving triglyceride-rich lipoproteins in healthy younger and middle-aged men.

Serum insulin-like growth factor-I level is independently associated with coronary artery disease progression in young male survivors of myocardial infarction: beneficial effects of bezafibrate treatment.

OBJECTIVES: We investigated whether the effect of bezafibrate on progression of coronary atherosclerosis in the BEzafibrate Coronary Atherosclerosis Intervention Trial (BECAIT) was related to insulin-like growth factor (IGF)-I and glucose-insulin homeostasis. BACKGROUND: BECAIT, the first double-blind, placebo-controlled, randomized, serial angiographic trial of a fibrate compound, demonstrated that progression of focal coronary atherosclerosis in young patients after infarction could be retarded by bezafibrate treatment. METHODS: The treatment effects on serum concentrations of IGF-I and insulin-like growth factor binding protein (IGFBP)-1, as well as on basal and postload glucose and insulin levels, were examined, and on-trial determinations were related to the angiographic outcome measurements. RESULTS: Bezafibrate treatment resulted in a significant reduction of serum IGF-I levels, both at two and five years, and on-trial serum IGF-I levels were directly related to changes in both minimal lumen diameter (r = 0.25, p < 0.05) and mean segment diameter (r = 0.29, p < 0.05). In contrast, none of the available indexes of insulin resistance (homeostasis model assessment estimate, basal and postload plasma insulin concentrations and serum IGFBP-1 levels) were related to the angiographic changes, nor were they significantly affected by bezafibrate treatment. Multiple stepwise regression analysis showed that the relation between on-trial serum IGF-I level and coronary artery disease (CAD) progression was independent of baseline angiographic score, age, body mass index, serum lipoprotein and plasma fibrinogen concentrations and measures of glucose-insulin homeostasis. CONCLUSIONS: IGF-I could be implicated in the progression of premature CAD, and a reduction of serum IGF-I concentration could account partly for the effect of bezafibrate on progression of focal coronary atherosclerosis.

Insulin and non-esterified fatty acid relations to alimentary lipaemia and plasma concentrations of postprandial triglyceride-rich lipoproteins in healthy middle-aged men.

AIMS/HYPOTHESIS: Enhanced and prolonged postprandial lipaemia is related to cardiovascular disease but how postprandial lipaemia is regulated is poorly known. We therefore determined the relations of fasting insulin concentrations to fasting and postprandial lipids, lipoproteins and non-esterified fatty acids in middle-aged men. METHODS: The subjects, 99 healthy 50-year-old men with an apolipoprotein E3/3 genotype, ate a mixed meal. The apolipoprotein B-48 and B-100 contents were determined in triglyceride-rich lipoproteins as a measure of chylomicron remnant and very low density lipoprotein particle concentrations. RESULTS: Fasting plasma insulin was associated with the triglyceride response to the test meal, independently of body mass index, waist-to-hip circumference ratio, blood glucose and the insulin effect on fasting plasma triglycerides. Exaggerated and prolonged postprandial lipaemia in subjects in the upper quartile of the plasma insulin distribution was largely accounted for by large (Svedberg flotation rate > 60) very low density lipoproteins and chylomicron remnants. Insulin relations to large postprandial triglyceride-rich lipoproteins exclusively reflected the association between plasma insulin and the fasting plasma concentrations of these lipoprotein species, whereas plasma insulin and late postprandial plasma concentrations of small (Svedberg flotation rate 20-60) chylomicron remnants were related, independently of insulin influences on fasting concentrations. Strong positive relations were found between the late increases in large triglyceride-rich lipoproteins and plasma non-esterified fatty acid concentrations after 6 h. CONCLUSION/INTERPRETATION: The degree of insulin sensitivity is a major determinant of postprandial lipaemia in healthy middle-aged men and could add to the regulation of the basal production of large triglyceride-rich lipoproteins.

Alimentary lipemia, postprandial triglyceride-rich lipoproteins, and common carotid intima-media thickness in healthy, middle-aged men.

BACKGROUND: Alimentary lipemia has been associated with coronary heart disease and common carotid artery intima-media thickness (IMT). This study was designed to investigate the relations of subclasses of postprandial triglyceride-rich lipoproteins (TRLs) with IMT. METHODS AND RESULTS: Ninety-six healthy 50-year-old men with an apolipoprotein (apo) E3/E3 genotype underwent an oral fat tolerance test and B-mode carotid ultrasound examination. The apo B-48 and apo B-100 contents of each fraction of TRLs were determined as a measure of chylomicron remnant and VLDL particle concentrations. In the fasting state, LDL cholesterol (P<0.05) and basal proinsulin (P<0. 05) were significantly related to IMT, whereas HDL cholesterol, plasma triglycerides, and insulin were not. In the postprandial state, plasma triglycerides at 1 to 4 hours (P<0.01 at 2 hours), total triglyceride area under the curve (AUC) (P<0.05), incremental triglyceride AUC (P<0.01), and the large VLDL (Sf 60 to 400 apo B-100) concentration at 3 hours (P<0.05) were significantly related to IMT. Multivariate analyses showed that plasma triglycerides at 2 hours, LDL cholesterol, and basal proinsulin were consistently and independently related to IMT when cumulative tobacco consumption, alcohol intake, waist-to-hip circumference ratio, and systolic blood pressure were included as confounders. CONCLUSIONS: These results provide further evidence for postprandial triglyceridemia as an independent risk factor for early atherosclerosis and also suggest that the postprandial triglyceridemia is a better predictor of IMT than particle concentrations of individual TRLs.

Persisting obesity starting before puberty is associated with stable intraabdominal fat during adolescence.

OBJECTIVES: To observe the evolution of intraabdominal adipose tissue (IAT) in obese prepubertal children, who did not change their degree of obesity during adolescence and to evaluate its relationship with metabolic risk indexes (RI). DESIGN: Longitudinal study of 16 obese adolescents (eight male and eight female) in whom relative body weight (RBW) did not change significantly and pubertal development was completed during the study period. MEASUREMENTS: Magnetic resonance imaging (MRI) scan at lumbar level (L4) three times during a 4 y period. At basal and at four years biochemical assays for metabolic indexes. RESULTS: IAT did not differ significantly over the three measurement times and showed significant correlations between first and second (r = 0.66, P < 0.005), first and third (r = 0.61, P < 0.01) and second and third values (r = 0.84, P < 0.0001). Subcutaneous adipose tissue (SAT) increased significantly from basal to third evaluation (P < 0.002). At baseline, IAT correlated significantly with lipids (total and LDL cholesterol r = 0.72, P < 0.004), while at the end of the study, IAT correlated positively with insulin (fasting insulin r = 0.55, P < 0.008, insulin area after oral glucose tolerance test (OGTT) r = 0.60, P < 0.03, fasting insulin/glucose r = 0.67 P < 0.006) and negatively with high density lipoprotein (HDL) cholesterol (r = -0.55, P < 0.04). CONCLUSIONS: Obesity achieved before puberty, and stable during adolescence, showed a relatively stable amount of IAT. In post pubertal children the relationship of IAT to clinically significant risk factors resemble the pattern in obese adults.

Treatment effects on serum lipoprotein lipids, apolipoproteins and low density lipoprotein particle size and relationships of lipoprotein variables to progression of coronary artery disease in the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT).

OBJECTIVES: To investigate the mechanisms by which bezafibrate retarded the progression of coronary lesions in the Bezafibrate Coronary Atherosclerosis Intervention Trial (BECAIT), we examined the relationships of on-trial lipoproteins and lipoprotein subfractions to the angiographic outcome measurements. BACKGROUND: BECAIT, the first double-blind, placebo-controlled, randomized serial angiographic trial of a fibrate compound, showed that progression of focal coronary atherosclerosis in young survivors of myocardial infarction could be retarded by bezafibrate treatment. METHODS: A total of 92 dyslipoproteinemic men who had survived a first myocardial infarction before the age of 45 years were randomly assigned to treatment for 5 years with bezafibrate (200 mg three times daily) or placebo; 81 patients underwent baseline and at least one post-treatment coronary angiography. RESULTS: In addition to the decrease in very low density lipoprotein (VLDL) cholesterol (-53%) and triglyceride (-46%) and plasma apolipoprotein (apo) B (-9%) levels, bezafibrate treatment resulted in a significant increase in high density lipoprotein-3 (HDL3) cholesterol (+9%) level and a shift in the low density lipoprotein (LDL) subclass distribution toward larger particle species (peak particle diameter +032 nm). The on-trial HDL3 cholesterol and plasma apo B concentrations were found to be independent predictors of the changes in mean minimum lumen diameter (r=-0.23, p < 0.05), and percent (%) stenosis (r = 0.30, p < 0.01), respectively. Decreases in small dense LDL and/or VLDL lipid concentrations were unrelated to disease progression. CONCLUSIONS: Our results suggest that the effect of bezafibrate on progression of focal coronary atherosclerosis could be at least partly attributed to a rise in HDL3 cholesterol and a decrease in the total number of apo B-containing lipoproteins.

Smaller, denser LDL particles are not a risk factor for cardiovascular disease in healthy nonagenarian women of the Cremona Population Study.

We evaluated LDL particle size and its relation with other established risk factors for cardiovascular disease in a group of healthy nonagenarian ( > or = 90 years) women participating in the Cremona Population Study. A group of younger healthy postmenopausal women (45-75 years) was used as control group. Nonagenarian women had significantly lower body mass index, systolic and diastolic blood pressure, and fasting insulin concentrations. Plasma total, LDL and HDL cholesterol, apo AI and apo B concentrations, and LpAI and LpAI:AII particles were significantly lower in the nonagenarian group as well. LDL particle size (262.7+/-0.9 vs. 270.1+/-1.1 A) was also lower in the nonagenarian group. The presence of the E4 isoform of apo E in the nonagenarian group resulted in significantly higher levels of plasma apo AI and LpAI:AII particles, and a trend toward larger LDL particles, and a lower diastolic blood pressure. In conclusion, smaller and denser LDL particles might not represent an important risk factor for cardiovascular disease in healthy nonagenarian women of the Cremona Population Study, characterised by a reduced number of LDL particles and other protective factors, like low systolic and diastolic blood pressure, body mass index, and plasma insulin levels.

New lysosomal acid lipase gene mutants explain the phenotype of Wolman disease and cholesteryl ester storage disease.

Deficiency of lysosomal acid lipase (LAL) leads to either Wolman disease (WD) or the more benign cholesteryl ester storage disease (CESD). To identify the molecular basis of the different phenotypes we have characterised the LAL gene mutations in three new patients with LAL deficiency. A patient with WD was homozygote for a null allele Y303X. The other two patients, with CESD, presented either homozygosity for T267I or compound heterozygosity consisting of Q64R and an exon 8 donor splice site substitution (G-->A in position -1). The mutants T267I and Q64R and the previously reported L273S, G66V, and H274Y CESD substitutions, overexpressed in stable clones, were found to be fully glycosylated and show an enzymatic activity of 3-8% of that of normal LAL. On the other hand, the delta254-277 mutant protein derived from exon 8 skipping and the Y303X protein were totally inactive. By transient transfection of hybrid minigene constructs, the CESD G-->A (-1) substitution resulted in partial exon inclusion, thus allowing the production of a small amount of normal LAL mRNA and hence of a functional enzyme. In contrast, a G-->A substitution observed in WD at position + 1 of the same exon 8 donor site resulted in complete exon skipping and the sole production of an inactive delta254-277 protein. In conclusion, LAL genotypes determine the level of residual enzymatic activity, thus explaining the severity of the phenotype.

Effects of a cardioselective beta-blocker on postprandial triglyceride-rich lipoproteins, low density lipoprotein particle size and glucose-insulin homeostasis in middle-aged men with modestly increased cardiovascular risk.

Beta-adrenergic receptor-blocking agents are commonly used for treatment of hypertension, angina pectoris and arrhythmias and as secondary prevention after myocardial infarction. The modest protection against myocardial infarction conferred by these compounds in primary-preventive studies has suggested that beneficial effects of beta-blockade are counteracted by known adverse influences on lipid and glucose metabolism. As most beta-blockers increase plasma triglycerides and decrease the high density lipoprotein (HDL) cholesterol concentration, a randomized, double-blind, cross-over study was conducted to evaluate whether a 12-week treatment with metoprolol (100 mg o.d.) or placebo affected the metabolism of postprandial triglyceride-rich lipoproteins in 15 middle-aged men with a modestly increased cardiovascular risk. Metoprolol treatment significantly increased the postprandial responses of very low density lipoprotein (VLDL) and VLDL remnants to a mixed meal-type of oral fat tolerance test. The effect was particularly prominent for larger (Svedberg flotation rate (Sf) > 400 and Sf 60-400) particle species (P < 0.001 in repeated measures ANOVA), whereas the smaller (Sf 20-60) particles were less affected (P < 0.05). The changes in the postprandial responses of the different VLDL species were mainly related to an effect on the fasting plasma concentrations, with limited or no influences on VLDL catabolism during the postprandial state. In contrast, metoprolol treatment did not significantly influence the postprandial responses of chylomicrons and chylomicron remnants. Notably, the enhanced fasting and postprandial triglyceridaemia during metoprolol treatment was neither accompanied by a rise in fasting or postprandial free fatty acid concentrations, nor by alterations of the glucose and insulin responses to a standard oral glucose challenge. The ensuing shift in the LDL particle size distribution towards smaller particles was limited (fraction small LDL: metoprolol 22.8 +/- 15.7% versus placebo 19.3 +/- 15.0%, P < 0.05). In conclusion, metoprolol treatment primarily enhances fasting and postprandial triglyceridaemia in middle-aged men by increasing the basal hepatic production of VLDL.