Association of endotoxemia with carotid atherosclerosis and cardiovascular disease: prospective results from the Bruneck Study

OBJECTIVES

Focus of the current study was on the significance of bacterial endotoxin, which shows a variety of pro-atherogenic properties and may occur at high concentration in the circulation of infected subjects.

BACKGROUND

The possibility of an infectious risk factor in atherogenesis and cardiovascular disease has stimulated research interest, but the nature of such process remains obscure.

METHODS

We measured plasma endotoxin levels (LAL assay) in a random population of 516 men and women 50 to 79 years old at the 1990 baseline evaluation (Bruneck Study). End points of this prospective survey were incident (early) atherosclerosis in the carotid arteries as assessed with high-resolution Duplex ultrasound (five-year follow-up rate, 98%) and incident cardiovascular disease (follow-up rate, 100%).

RESULTS

Median endotoxin concentration amounted to 14.3 pg/ml (range, 6.0 to 209.2 pg/ml). Subjects with levels beyond 50 pg/ml (90th percentile) faced a threefold risk of incident atherosclerosis (odds ratio [95% confidence interval] 2.9 [1.4-6.3]; p < 0.01). The risk associated with high endotoxin was most pronounced in subjects with chronic infections and in current and ex-smokers. Notably, smokers with low endotoxin levels and nonsmokers did not differ in their atherosclerosis risk, whereas smokers with high levels almost invariably developed new lesions. All findings emerged as independent of vascular risk factors. Similar results were obtained for incident cardiovascular disease.

CONCLUSIONS

The current study yields first epidemiologic evidence that endotoxemia constitutes a strong risk factor of early atherogenesis in subjects with chronic or recurrent bacterial infections and a link in the association between cigarette smoking and atherosclerotic disease.

Association of serum antibodies to heat-shock protein 65 with carotid atherosclerosis : clinical significance determined in a follow-up study

BACKGROUND

Previous work has proved that increased titers of antibodies against heat-shock protein (hsp) 65 are associated with atherosclerotic lesions independently of other established risk factors. The present follow-up study was designed to further scrutinize the association of hsp antibodies and atherosclerosis and evaluate the possible predictive value of these antibodies for the development and/or progression of lesions in the same population.

METHODS AND RESULTS

A total of 750 subjects 45 to 74 years old were recruited, and the rate of participation was 93.6%; 58 subjects died between 1990 and 1995. All participants were subjected to determination of serum antibodies against hsp65 and sonography to assess carotid atherosclerotic lesions and evaluate other risk factors, ie, age, sex, body mass index, blood cholesterol, apolipoprotein B, apolipoprotein A, triglycerides, lipoprotein(a), fibrinogen, leukocyte number, antithrombin III, ESR, ferritin, hypertension, smoking, and diabetes mellitus. Our data show that hsp65 antibody titers in the population emerged as highly consistent over a 5-year observation period (r=0.78, P<0.0001). Titers were significantly elevated in subjects with progressive carotid atherosclerosis and correlated with intima/media thickness. Multiple linear regression analysis documented these associations to be independent of age, sex, and other risk factors. Subanalyses revealed a preferential association of hsp65 antibody titers with advanced lesions (odds ratio, 1.42; 95% CI, 1.02 to 1.98; P=0.039). Other risk factors neither confounded nor modified this association. Finally, hsp65 antibody titers significantly predicted the 5-year mortality (hazard ratio, 1.52; 95% CI, 1.14 to 2.03; P<0.001).

CONCLUSIONS

These findings indicate a sustained existence of anti-hsp65 antibodies in subjects with severe atherosclerosis, which is predictive for mortality.

Role of lipoprotein(a) and apolipoprotein(a) phenotype in atherogenesis: prospective results from the Bruneck study

BACKGROUND

Experimental studies have suggested both atherogenic and thrombogenic properties of lipoprotein(a) [Lp(a)], depending on Lp(a) plasma concentrations and varying antifibrinolytic capacity of apolipoprotein(a) [apo(a)] isoforms. Epidemiological studies may contribute to assessment of the relevance of these findings in the general population.

METHODS AND RESULTS

This study prospectively investigated the association between Lp(a) plasma concentrations, apo(a) phenotypes, and the 5-year progression of carotid atherosclerosis assessed by high-resolution duplex ultrasound in a random sample population of 826 individuals. We differentiated early atherogenesis (incident nonstenotic atherosclerosis) from advanced (stenotic) stages in atherosclerosis that originate mainly from atherothrombotic mechanisms. Lp(a) plasma concentrations predicted the risk of early atherogenesis in a dose-dependent fashion, with this association being confined to subjects with LDL cholesterol levels above the population median (3.3 mmol/L). Apo(a) phenotypes were distributed similarly in subjects with and without early carotid atherosclerosis. In contrast, apo(a) phenotypes of low molecular weight emerged as one of the strongest risk predictors of advanced stenotic atherosclerosis, especially when associated with high Lp(a) plasma concentrations (odds ratio, 6.4; 95% CI, 2.8 to 14. 9).

CONCLUSIONS

Lp(a) is one of the few risk factors capable of promoting both early and advanced stages of atherogenesis. Lp(a) plasma concentrations predicted the risk of early atherogenesis synergistically with high LDL cholesterol. Low-molecular-weight apo(a) phenotypes with a putatively high antifibrinolytic capacity in turn emerged as one of the leading risk conditions of advanced stenotic stages of atherosclerosis.

Plasma glucose within the normal range is not associated with carotid atherosclerosis: prospective results in subjects with normal glucose tolerance from the Bruneck Study

OBJECTIVE

There is substantial evidence that glucose intolerance is associated with an increased risk of cardiovascular disease. However, it is not well established whether plasma glucose is independently related to atherosclerosis when glucose tolerance is normal and, if so, to which stage of the complex atherosclerotic process.

RESEARCH DESIGN AND METHODS

We prospectively examined the status of carotid arteries in 625 subjects aged 40-79 years who were randomly selected from the general population and had normal glucose tolerance (according to World Health Organization criteria) both at baseline and at 5 years of follow-up. All subjects had high-resolution echo-duplex evaluation of the common and internal carotid arteries (eight regions of interest on both sides) in 1990 and 1995 to detect the change in carotid status over time. The occurrence of new plaques in previously normal segments was termed "incident nonstenotic" or "early atherosclerosis," and the occurrence of stenosis in >40% of previously normal segments was termed "incident stenotic" or "advanced atherosclerosis." In addition, we evaluated the changes in the atherosclerosis score (the sum of all plaques) during the follow-up, and we measured intimal-medial thickening (IMT) in the common carotid artery in 1995. In all subjects, several candidate risk factors were assessed: sex, age, BMI, waist-to-hip ratio, glucose, HbA1c, insulin, urate, lipids, apolipoproteins A1 and B, blood pressure, lipoprotein(a), fibrinogen, antithrombin III, factor V Leiden mutation, ferritin, leukocyte count, smoking, alcohol intake, physical activity, and socioeconomic status. Fasting plasma glucose (FPG), plasma glucose 2 hr after the glucose load (2-h PG), and HbA1c concentrations in 1990 and 1995 were averaged in each subject to obtain an estimate of long-term glucose exposure of the arterial wall.

RESULTS

Linear or logistical regression analyses indicated that neither baseline glucose and HbA1c levels nor mean FPG, mean 2-h PG, or mean HbA1c in 1990 and 1995 were independently related to IMT, a 5-year change in the atherosclerotic score, incident nonstenotic (early) atherosclerosis, or incident stenotic (advanced) atherosclerosis. Likewise, subjects with FPG levels above the median and subjects in the new category of "impaired fasting glucose" did not have an increased occurrence or progression of atherosclerosis. All results were consistent before and after adjustment for other vascular risk factors and possible confounders.

CONCLUSIONS

These results suggest that plasma glucose levels within the normal range (<7.8 mg/dl both at FPG and 2-h PG) are not independently related to any stage of atherosclerosis.

TARPARE: a method for selecting target audiences for public health interventions

OBJECTIVE

This paper presents a model to assist the health promotion practitioner systematically compare and select what might be appropriate target groups when there are a number of segments competing for attention and resources.

METHOD

TARPARE assesses previously identified segments on the following criteria: T: The Total number of persons in the segment; AR: The proportion of At Risk persons in the segment; P: The Persuability of the target audience; A: The Accessibility of the target audience; R: Resources required to meet the needs of the target audience; and E: Equity, social justice considerations. The assessment can be applied qualitatively or can be applied such that scores can be assigned to each segment. Two examples are presented.

CONCLUSIONS

TARPARE is a useful and flexible model for understanding the various segments in a population of interest and for assessing the potential viability of interventions directed at each segment. The model is particularly useful when there is a need to prioritise segments in terms of available budgets.

IMPLICATIONS

The model provides a disciplined approach to target selection and forces consideration of what weights should be applied to the different criteria, and how these might vary for different issues or for different objectives. TARPARE also assesses segments in terms of an overall likelihood of optimal impact for each segment. Targeting high scoring segments is likely to lead to greater program success than targeting low scoring segments.

Abdominal obesity reduction in indigenous men

OBJECTIVES

To assess the effectiveness of a men's 'waist loss' program over one year in Indigenous men.

DESIGN

Pre-and post-test measurements of 47 Indigenous men on four island groups in the Torres Strait region of Northern Australia involved in a version of the 'GutBuster' program, modified by and for Indigenous men.

RESULTS

Weight, waist and hip size of 47 men, and body fat estimated from electrical impedence measures of 27 men, were compared at baseline, after approx 2 months, approx 6 months and approx one year. Average weight loss was 3.3 kg (3.5%), and waist loss 4.0 cm (3.5%). The average percentage decrease in fat mass (FM) was 10.8%. An environmental audit technique highlighted modifications needed to the environment to assist behaviour change.

CONCLUSIONS

Education-behaviour change interventions of this kind may offer opportunities for health improvements in Indigenous men.

Poor response to activated protein C as a prominent risk predictor of advanced atherosclerosis and arterial disease

BACKGROUND

The potential role of activated protein C (APC) resistance in arterial thrombosis and disease is a matter of ongoing controversy.

METHODS AND RESULTS

In the present population-based survey, a random sample of 826 men and women underwent high-resolution duplex ultrasound scanning of the carotid and femoral arteries. Response to APC was expressed in APC ratios. Subjects were tested for the factor V Leiden mutation. The risk of carotid stenosis increased gradually with decreasing response to APC (adjusted OR [95% CI] for a 1-U decrease of response to APC, 1.6 [1. 2 to 2.2]), as did the risk of femoral artery stenosis (1.7 [1.3 to 2.3]) and prevalent cardiovascular disease (1.4 [1.1 to 2.0]). The association between low APC ratio and atherosclerotic vascular disease applied equally to subjects with the factor V Leiden mutation and those without. Our study identified various nongenetic determinants of poor response to APC in the general population, including behavioral, hormonal, and environmental factors.

CONCLUSIONS

The present study revealed an independent and gradual association between low response to APC and both advanced atherosclerosis (stenosis) and arterial disease. Resistance to APC due to factor V Leiden mutation was only one facet of this relationship.

Prevalence of insulin resistance in metabolic disorders: the Bruneck Study

The prevalence of insulin resistance in the most common metabolic disorders is still an undefined issue. We assessed the prevalence rates of insulin resistance in subjects with impaired glucose tolerance (IGT), NIDDM, dyslipidemia, hyperuricemia, and hypertension as identified within the frame of the Bruneck Study. The study comprised an age- and sex-stratified random sample of the general population (n = 888; aged 40-79 years). Insulin resistance was estimated by homeostasis model assessment (HOMA(IR)), preliminarily validated against a euglycemic-hyperinsulinemic clamp in 85 subjects. The lower limit of the top quintile of HOMA(IR) distribution (i.e., 2.77) in nonobese subjects with no metabolic disorders (n = 225) was chosen as the threshold for insulin resistance. The prevalence of insulin resistance was 65.9% in IGT subjects, 83.9% in NIDDM subjects, 53.5% in hypercholesterolemia subjects, 84.2% in hypertriglyceridemia subjects, 88.1% in subjects with low HDL cholesterol, 62.8% in hyperuricemia subjects, and 58.0% in hypertension subjects. The prevalence of insulin resistance in subjects with the combination of glucose intolerance (IGT or NIDDM), dyslipidemia (hypercholesterolemia and/or hypertriglyceridemia and/or low HDL cholesterol), hyperuricemia, and hypertension (n = 21) was 95.2%. In isolated hypercholesterolemia, hypertension, or hyperuricemia, prevalence rates of insulin resistance were not higher than that in nonobese normal subjects. An appreciable number of subjects (n = 85, 9.6% of the whole population) was insulin resistant but free of IGT, NIDDM, dyslipidemia, hyperuricemia, and hypertension. These results from a population-based study documented that 1) in hypertriglyceridemia and a low HDL cholesterol state, insulin resistance is as common as in NIDDM, whereas it is less frequent in hypercholesterolemia, hyperuricemia, and hypertension; 2) the vast majority of subjects with multiple metabolic disorders are insulin resistant; 3) in isolated hypercholesterolemia, hyperuricemia, or hypertension, insulin resistance is not more frequent than can be expected by chance alone; and 4) in the general population, insulin resistance can be found even in the absence of any major metabolic disorders.

Alcohol consumption and atherosclerosis: what is the relation? Prospective results from the Bruneck Study

BACKGROUND AND PURPOSE

Potential effects of regular alcohol consumption on atherogenesis are still controversial mainly due to the lack of prospective population-based studies.

METHODS

The Bruneck Study is a prospective population-based survey of atherosclerosis and its risk factors. The study population comprises a sex- and age-stratified random sample of men and women aged 40 to 79 years. Participation and follow-up were more than 90% complete. Changes in carotid atherosclerosis between the 1990 baseline and the first follow-up in 1995 were monitored by high-resolution duplex ultrasonography. Alcohol intake was quantified with a standardized questionnaire and prospective diet records.

RESULTS

Alcohol consumption less than once a week (occasional drinking) had no effect on atherogenesis. The association between regular alcohol intake and incident carotid atherosclerosis (early atherogenesis) was J-shaped, with light drinkers facing a lower risk than either heavy drinkers or abstainers. Protection offered by alcohol consumption of <50 g/d appeared to act through inhibition of the injurious action of high levels of low-density lipoprotein (LDL) cholesterol. Excess risk of incident atherosclerosis observed among heavy alcohol consumers (> or =100 g/d) clearly surpassed the risk burden afforded by heavy smoking. The association between regular alcohol intake and incident carotid stenosis (advanced atherogenesis) was U-shaped. Odds ratios were generally shifted toward protection and did not rely on LDL cholesterol levels. We failed to find any differential effects of alcohol from various sources. All associations remained independently significant when we adjusted for lifestyle, coincidental smoking, and the metabolic complex associated with drinking.

CONCLUSIONS

Our findings support the view that adverse and beneficial effects of alcohol on arterial disease are mediated in part by a dose-dependent promotion or deceleration of atherogenesis. The protection afforded by light drinking may possibly be attributed to antithrombotic effects and inhibition of the atherogenic action of high levels of LDL cholesterol.

U-shaped and J-shaped relationships between serum insulin and coronary heart disease in the general population. The Bruneck Study

OBJECTIVE

To evaluate the relationship existing between serum insulin and coronary heart disease (CHD) in the general population.

RESEARCH DESIGN AND METHODS

In a cross-sectional survey on atherosclerosis and its risk factors, 500 men and 500 women aged 40-79 years were randomly selected from the population of Bruneck, Italy. Clinical, biochemical, and behavioral risk factors of atherosclerosis were assessed in the 936 subjects who participated in the study. Serum insulin was measured at fasting (n = 888) and 2 h (n = 811, known diabetic subjects were excluded) after an oral glucose load. CHD was ascertained by an abnormal electrocardiogram and/or a history of angina or myocardial infarction.

RESULTS

Subjects were stratified according to serum insulin quintiles at fasting or 2 h after glucose loading. After adjustment for sex, age, BMI, smoking, physical activity, alcohol intake, and socioeconomic status (analysis of covariance), cardiovascular risk factors clustered in subjects of the top insulin quintile. Multiple logistic regression analysis, including sex and age in model 1, sex, age, BMI, glucose tolerance, socioeconomic status, and behavioral variables in model 2, or this set of variables together with triglycerides and apoproteins A1 and B, fibrinogen, and blood pressure status in model 3, revealed a significant association between high serum insulin and CHD when median insulin quintile was used as the reference class. Moreover, low serum insulin levels, such as those found in subjects of the lowest quintile, were independently related to CHD. These results were found either before (model 1) or after (models 2 and 3) adjusting for several covariates. Consistent results were found in men and women, as well as in younger and older subjects.

CONCLUSIONS

Results of the present study suggest that both hyperinsulinemia and "hypoinsulinemia" are independent indicators of CHD. Furthermore, it is proposed that the relationship between CHD and fasting insulin is U-shaped, whereas that between CHD and postglucose insulin may be J-shaped.

Effect of steroid treatment on the migration behaviour of neutrophils in patients with early rheumatoid arthritis

The influence of methylprednisolone on the migratory characteristics of neutrophil granulocytes was investigated in 10 patients with early rheumatoid arthritis (RA) and compared to 12 controls. The migration of neutrophils was measured with a whole-blood membrane filter assay with and without stimulation by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Total migration index (TMI), distribution characteristics (DC) and the product of TMI and DC (neutrophil migratory activity; NMA) served to characterize the migratory behaviour of neutrophils. The data demonstrated an increased polymorphonuclear leucocyte (PMN) migration in patients with early RA, indicating a bystander role of PMNs in inflammatory joint injury. Treatment with methylprednisolone reduced significantly the penetration depth (DC) of neutrophils, but did not influence the number of migrating cells (TMI). The unstimulated NMA was significantly reduced due to the marked DC reduction, whereas steroids did not influence the stimulated NMA of neutrophils. A significant reduction in PMN penetration depth was demonstrated only after a steroid therapy of at least 10 days, suggesting that a longer period of steroid therapy is necessary to provide effective inflammatory control.

Abnormal directed migration of blood polymorphonuclear leukocytes in rheumatoid arthritis. Potential role in increased susceptibility to bacterial infections

Rheumatoid arthritis (RA) patients are at higher risks of bacterial infection than healthy subjects. Polymorphonuclear leukocytes (PMN) are the first line of nonspecific cellular defence against these infections. We tested the hypothesis that abnormal directed migration of PMN may be one reason for the increased infection rate of RA patients. PMN migration was investigated in 68 peripheral blood samples of 15 RA patients compared with 64 samples of healthy controls in a novel whole blood in vitro membrane filter assay. The migration of PMNs from RA patients and controls was stimulated using the bacterial chemoattractant N-formyl-methionyl-leucyl-phenylalanine (fMLP). Unstimulated PMN migration of RA patients was increased compared with healthy controls as measured by the following parameters: (a) absolute number of migrant PMNs (1954+/-87 vs. 1238 +/-58 PMN/mm2), (b) percentage of PMNs migrated into the filter (total migration index, TMI) (28.6+/-0.9 vs. 24.0+/-0.8%), (c) the distance half the migrating PMNs had covered (distribution characteristic, DC) (22.6+/-1.1 vs. 16.1+/-0.6 mm) and (d) the product of TMI and DC (neutrophil migratory activity, NMA) (669.0+/-45.0 vs. 389.0+/-18.9). fMLP stimulated PMNs of RA patients showed defective migration compared to unstimulated samples as shown by (a) a reduced number of migrant PMNs (1799+/-93 PMN/mm2), (b) lower TMI (26.1+/-0.9%), (c) unremarkable altered distribution characteristic (22.9+/-0.8 mm) and (d) significant reduced migratory activity (600.0+/-30.0). Our data suggest that the high incidence of infections in RA patients may partly be caused by defective migratory activity of PMNs to bacterial chemoattractants as demonstrated by fMLP.

Body iron stores and the risk of carotid atherosclerosis: prospective results from the Bruneck study

BACKGROUND

Fe2+ released from tissue iron stores may accelerate lipid peroxidation by virtue of its pro-oxidant properties and thus promote early atherogenesis.

METHODS AND RESULTS

The present prospective survey addresses the potential association between serum ferritin concentrations and the 5-year progression of carotid atherosclerosis as assessed by ultrasonographic follow-up evaluations. The study population comprises a random sample of 826 men and women 40 to 79 years old. Serum ferritin was one of the strongest risk predictors of overall progression of atherosclerosis. The main part of this association appeared to act through modification of the atherogenic potential of LDL cholesterol (OR [95% CI] for a 1-SD unit increase in ferritin at LDL levels of 2.5, 3.6, and 4.9 mmol/L: 1.55 [1.30 to 1.85], 1.77 [1.40 to 2.24], and 2.05 [1.50 to 2.80]; P=.0012 for effect modification). Changes in iron stores during the follow-up period modified atherosclerosis risk, in that a lowering was beneficial and further iron accumulation exerted unfavorable effects. All these findings applied equally to incident atherosclerosis and the extension of preexisting atherosclerotic lesions. The significance of prominent iron stores in the development of carotid stenosis was clearly less pronounced. Finally, ferritin and LDL cholesterol showed a synergistic association with incident cardiovascular disease and death (n=59).

CONCLUSIONS

The present study provided strong epidemiological evidence for a role of iron stores in early atherogenesis and suggests promotion of lipid peroxidation as the main underlying pathomechanism. This hypothesis could in part explain the sex difference in atherosclerotic vascular disease.

Changes in the polymorphonuclear leukocyte function of blood samples induced by storage time, temperature and agitation

We have investigated changes in polymorphonuclear leukocyte (PMN) functions of blood samples caused by such typical elements of laboratory handling as storage time, temperature and agitation. The blood of five healthy subjects was stored upright in test tubes at 4, 22 and 37 degrees C over periods of 20 min, one, two, six and 24 h. Controlled agitation was performed on a shaker. The following PMN functional parameters were measured: the white blood cell count (WBC), migration, elastase (EL) release, reactive oxygen species (ROS) production and lipid peroxidation. Migration was determined in a whole-blood membrane filter assay; ROS production by latex-stimulated, luminol-enhanced chemiluminescence (CL) in a whole-blood assay; EL as EL alpha 1-antitrypsin complex; and lipid peroxidation by malondialdehyde (MDA) generation. The reactions after handling were compared with the values measured immediately after blood withdrawal which served as reference values of 'genuine' PMN reactivity. The outstanding result was the marked scatter between the individual reactions. Overall, the proportion of migrating PMNs in the blood total decreased, while CL, correlating positively with MDA, increased with the time of storage. EL increased considerably in some of the samples. Agitation raised CL and MDA. The effect of temperature was apparent only after 24 h at 37 degrees C. There was evidence that inhomogeneities in the blood samples were another interfering factor, since resuspension of sedimented blood after storage can be incomplete. In order to obtain reliable results from PMN functional tests, whole-blood assays and processing of blood samples within 20 min after blood withdrawal are recommended.

Relationship between insulin and carotid atherosclerosis in the general population. The Bruneck Study

BACKGROUND AND PURPOSE

Although several studies have investigated the association between insulin and coronary heart disease, the relationship between this hormone and carotid atherosclerosis is not well established.

METHODS

As a part of a population-based survey on atherosclerosis and its risk factors, serum insulin was measured at fasting (n = 888) and at 2 hours after an oral glucose load (n = 811; known diabetic subjects were excluded). The study population comprised an age- and sex-stratified random sample of men and women aged 40 to 79 years. Atherosclerosis in the common and internal carotid arteries was assessed twice (in 1990 and 1995) by duplex sonography. Progression during the 5-years follow-up was defined by an increase in the atherosclerosis score of more than the doubled measurement error (> 27%) or by the occurrence of new plaques. Subjects were stratified in quintiles according to baseline serum insulin at fasting or 2 hours after glucose loading.

RESULTS

Logistic regression analysis revealed a significant association of carotid atherosclerosis with both low and high insulin (U-shaped relation). This finding was found before and after adjustment for several covariates (sex, age, body mass index, glucose tolerance, triglycerides, apolipoproteins Al and B, fibrinogen, blood pressure status, behavioral variables, and socioeconomic status). This relation applied equally to fasting and postglucose insulin and was more pronounced in the prospective analysis than in the cross-sectional analysis.

CONCLUSIONS

We conclude that both "hypoinsulinemia" and hyperinsulinemia are independent risk indicators of carotid atherosclerosis.

The role of insulin in age-related sex differences of cardiovascular risk profile and morbidity

Metabolic changes and shifts in vascular risk profiles during and after menopause may partly explain the loss of premenopausal protection against cardiovascular disease (CVD). The current population-based survey addresses changes in risk factors and insulin levels across an age range of 40-79 years in men and women. Population recruitment was performed as part of the Bruneck Study from July to November 1990. In brief, of 1000 subjects randomly selected for inclusion 936 participated, with insulin measurements available in a random subgroup of 880 men and women, 60 of whom were excluded due to manifest diabetes mellitus. Insulin concentrations were assessed according to Hales and Randle and by a human insulin-specific radioimmunoassay. A rise in insulin concentrations with advancing age in women (5th-8th decade, 10.5-14.4 mU/l or +1.2%/year) contrasts with a marked gradual decline in insulin levels in men (5th-8th decade, 12.5-5.9 mU/l or -2.4%/year). Age trends of insulin concentrations in sexes emerged as independent of age-related changes in body weight, type of fat distribution, alcohol consumption, cigarette smoking, social status, fasting glucose, and physical activity (P < 0.001 for sex-specific difference in the regression slopes). Insulin levels in pre- and postmenopausal women of equal age differed significantly (10.1 vs. 13.9 mU/l, P = 0.003), thus advocating that variations of insulin observed may in part be related to shifts in sex hormone status. Levels of virtually all vascular risk attributes were lower in premenopausal women than in men of equal age, but the opposite was true for the elderly. The switch in the sex preponderance of vascular risk factors may be crucially involved in closing the CVD incidence gap between genders after menopause. The analysis suggests that variations in insulin levels are a common metabolic basis for sex/age trends in fasting glucose, apolipoprotein B, total cholesterol, total cholesterol/HDL cholesterol ratio, LDL density (LDL cholesterol/apolipoprotein B), triglycerides and systolic blood pressure.

Influence of age on the release of reactive oxygen species by phagocytes as measured by a whole blood chemiluminescence assay

Polymorphonuclear and mononuclear phagocytes play an important role in host defense, but may also cause tissue injury through excessive inflammation. Reactive oxygen species (ROS) are not only directly ore indirectly involved in a wide variety of clinical disorders, such as atherosclerosis, reperfusion injury, pulmonary toxicity and cancer, but they are also important in the aging process. This process is associated with increasing susceptibility to infection. In this study we investigated the influence of age and sex on phagocyte activation by means of a whole blood chemiluminescence (CL) assay. Circulating phagocyte activity was measured in 55 healthy volunteers (24 females, 31 males) aged from 6 to 92 years. Using an automated luminescence system, phagocytes were stimulated by polystyrene beads and Luminol-enhanced CL was determined in terms of peak height and peak time in freshly withdrawn, peripheral venous whole blood. An extremely significant positive correlation (p < 0.0001) between the maximum of light emission after stimulation and increasing age was found. This finding is true for the total population of blood phagocytes as well as for a single cell. In contrast the time of the appearance of the maximum of light emission showed an extremely significant inverse correlation (p < 0.0003) with increasing age. The influence of sex on the CL-parameters showed no significant difference between women and men. It is concluded that the increased susceptibility of circulating phagocytes to oxidative burst in elderly subjects may be the consequence of several biological events. Senescent cells express more and also have new antigens on their surfaces that trigger an autoimmune response. Cellular senescence appears earlier in old organisms. Therefore phagocytes in aging individuals may be increasingly involved in their scavenger tasks that grow with the catabolic bias in cell turnover. Moreover, atherosclerotic alterations in the intima and endothelial lesions are physiologic concomitants of age and may lead to a stimulation of circulating phagocytes.

Insulin sensitivity and regular alcohol consumption: large, prospective, cross sectional population study (Bruneck study)

OBJECTIVES

To assess the relation between regular alcohol consumption and insulin sensitivity, and to estimate the importance of insulin in the association of alcohol with multiple vascular risk factors and cardiovascular disease.

DESIGN

Prospective and cross sectional study of a large randomly selected population sample.

SETTING

Part of the Bruneck study 1990-5 (Bolzano province, Italy).

SUBJECTS

820 health, non-diabetic women and men aged 40-79 years.

MAIN OUTCOME MEASURE

Concentrations of fasting and post-glucose insulin, cholesterol, apolipoproteins, triglycerides, Lp(a) lipoprotein glucose, fibrinogen, and antithrombin III; blood pressure; insulin resistance estimated by the homeostasis model assessment.

RESULTS

Fasting insulin concentrations in those who did not drink alcohol and subjects reporting low (1-50 g/day), moderate (51-99 g/day), and heavy (> or = 100 g/day) alcohol intake were 12.4, 10.0, 8.7, and 7.1 mU/l (P < 0.001). Likewise, post-glucose insulin concentrations and estimates for insulin resistance assessed by the homeostasis model assessment decreased significantly with increasing amounts of regular alcohol consumption. These trends were independent of sex, body mass index, physical activity, cigarette smoking, medication, and diet (P < 0.001). Regular alcohol intake predicted multiple changes in vascular risk factors over a five year period including increased concentrations of high density lipoprotein cholesterol and apolipoprotein A I; higher blood pressure; and decreased concentration of antithrombin III. These associations were in part attributable to the decrease in insulin concentrations observed among alcohol consumers.

CONCLUSIONS

Low to moderate amounts of alcohol, when taken on a regular basis, improve insulin sensitivity. Insulin is a potential intermediate component in the association between alcohol consumption and vascular risk factors (metabolic syndrome).

The influence of trauma on changes in neutrophil granulocyte function assessed by an analysis of granulocyte migration

We examined the effects of trauma on polymorphonuclear leucocyte (PMN) migratory parameters and PMN elastase release, with the aim of tracing an acute inflammatory reaction from its very beginning to the phase of recovery. Fifteen patients who underwent monotrauma surgery, followed by uneventful healing, served as inflammation model. PMN activation was studied by measuring their readiness to migrate (TMI) and their penetration potency (DC) in a whole blood membrane filter device, in which a chemoattractant depot (FMLP) was integrated. Control chambers lacking FMLP provided parameters of the spontaneous migration. In healthy controls (n = 64), the numbers of invading PMNs decreased continuously from the outermost layer towards the interior of the filter device. FMLP did not influence the mobilization rate of PMNs immigrant from the blood into the filter, but those cells that did migrate penetrated deeper (P < 0.05). After trauma, the spontaneous and FMLP-stimulated DC was increased (P < 0.05). Trauma also tended to inhibit PMN migratory activity episodically; depression of the unspecific immune function (low TMI values) was found on the 3rd (P < 0.0001) and 12th (P < 0.01) postsurgical days. There was no correlation between the migratory parameters and the inflammation parameter, PMN elastase release. Preliminary results indicate that analyses of PMN migratory parameters by a whole blood membrane filter assay could provide a valuable adjunct in monitoring trauma-associated immunologic changes.

Effectiveness of an abdominal obesity reduction programme in men: the GutBuster "waist loss' programme

OBJECTIVE

To examine the long term (1-2 year), as well as immediate effectiveness of a "waist loss' programme for men.

DESIGN

Two preliminary studies are reported; one following a small group of 42 men over two years after a 6 week "GutBuster' course, the second following men for 1 year after having completed the initial 6 week programme (n = 83), or the initial course plus an additional six fortnightly "advanced' course (n = 37).

MEASUREMENTS

Waist, hip and weight measures were reported for the 2 year group; waist and hip only in study 2. Dietary fat, exercise and alcohol intake were also recorded in study 2 through the use of questionnaires. The goal for the initial course was a 1% waist loss per week.

RESULTS

All groups achieved an average waist loss > 1%/week during the initial programme. Waist sizes reported in study 1 were significantly less after 2 years (t = 8.28, p < 0.001) averaging a 6% loss in the group. This equated with an average weight loss of 5.5 kg. A repeated measures ANOVA also showed a significant main effect (F = 85.35; p < 0.0001) for waist losses and an interaction effect (F = 16.53; p < 0.0001) between initial and advanced groups after 1 year in study 2. Average waist losses were 4% and 10% respectively. There were also significant changes in dietary fat intake, exercise and alcohol consumption.

CONCLUSION

Reductions in waist size in men appear to be more feasible than weight losses in women. "Waist loss' may also be a more valid measure of fat loss in men that body mass measures.

[Hypertrophic callus formation and craniocerebral trauma: early diagnosis and behavior of basic fibroblast growth factor]

Hypertrophic callus formation in patients with severe head injury leads to an early fracture consolidation, whereas in joint fractures the enhanced ossification can even end in ankylosis of the injured joint. It is already known that these ossifications can be at least partly prevented by non-steroid anti-inflammatory drugs. Therefore, serum parameters have been determined that could predict this phenomenon. The mean values for alkaline phosphatase (ALP) and its bone isoenzyme were significantly increased in patients with severe head injury and bone fractures as soon as the 2nd week (reaching peak values in the 3rd week after injury) compared with patients with isolated fractures or head injury only and with normal healthy subjects. Procollagen I (PICP) was significantly increased even in the 1st week, reaching its peak during the 2nd week after injury. Compared with the callus volume at the time of fracture consolidation the size was determined from the X-rays--it was even possible to predict the volume of callus with the aid of these serum parameters as early as in the first few weeks after injury. A possible link between head injury and the increased bone formation could be the basic fibroblast growth factor (bFGF). In our study, bFGF was determined in serum by an immunoassay (ELISA), and an unusual pattern of dynamic change was observed in the patients with head injury and bone fractures. Compared with patients with isolated bone fractures bFGF immunoreactivity was significantly increased in patients with brain and bone lesions even in the 1st week after injury, with further peaks in the 2nd, 4th and 7th-8th weeks, with sudden decreases in between. In patients with isolated bone fractures a transient increase of bFGF was observed only during the 2nd week after injury. A similar increase was also determined in the sera of patients with head injury only, but it lasted longer. Thus, a posttraumatic increase of the serum bFGF was induced by bone as well as by brain injury, but was not causally related with the growth-promoting effects of the sera, as was proven by an in vitro analysis of the effects of the patients sera on L929 fibroblast growth.

Blood polymorphonuclear leukocyte migratory activities during rheumatoid arthritis

Blood polymorphonuclear leukocyte (PMN) migratory activity was investigated in adult rheumatoid arthritis (RA) patients and in healthy control subjects using fresh whole blood in a novel membrane filter assay. The PMNs migrated under FMLP stimulation and under blank control conditions (spontaneous migration). Essential evaluation criteria were the percentage of PMNs that migrated from the entire blood sample into the filters (TMI) and the penetration depth of the migrating cell bulk into the filters (DC). PMNs from healthy subjects penetrate deeper under FMLP stimulation than under blank control conditions. Migration depends on age and sex: the TMI decreases, while the DC and the reactivity towards FMLP increase with age. FMLP triggers a stronger DC reaction in females than in males. Compared with healthy subjects, patients with RA develop an increased PMN reaction, whereas FMLP inhibits migration in comparison with the blank controls. There is no correlation between disease activity estimated by joint functions and PMN migratory activity, while there are strong correlations between disease activity and the classical RA laboratory parameters WBC, platelets, BSR, CRP, hemoglobin and rheumatoid factor. PMNs therefore probably do not play a major role in joint injury. Gold therapy inhibits DC reactivity. PMN migration in RA differs markedly from the reactions in juvenile rheumatoid arthritis, where high disease activity is associated with high PMN migratory activity, and the correlations between classical laboratory parameters and disease activity follow other patterns than in RA.

Neutrophil Migration Activity (NMA) - A new migration test for the monitoring of wound healing in traumatology?

A new PMN migration test was introduced in traumatology to measure the acute, inflammatory response after surgery in a patient with uncomplicated wound healing and in a case of acute, early postoperative infection. Polymorphonuclear neutrophil granulocyte (PMN) - behaviour was studied by quantifying the neutrophil migration activity (NMA), which combines PMN-stimulation and PMN-distribution in a migration filter device simulating "in vivo"-conditions. While in uncomplicated wound healing the NMA was within the normal range, in an acute, early infection migratory stimulation reached a maximum on the 5th postsurgical day followed by a decrease during the following days. This decrease is probably an expression of an increased PMN-turnover and excessive phagocytosis. PMN-behaviour changing from migration to phagocytosis is regarded as an indicator of wound healing complications before clinical symptoms occur.