Biomedical subjects

S Kiechl

Publications and source records attributed to S Kiechl.

At least 55 records · Page 3Linked to original sources

PubMed1999

Reversible severe myopathy of respiratory muscles due to adult-onset type III glycogenosis.

Subacute severe myopathy of the respiratory muscles developed in a 47-year-old woman after a 3-week period of strict fasting. Histological and biochemical work-up of muscle biopsy specimens permitted the diagnosis of debrancher deficiency. The course of the disease was characterized by subacute respiratory failure and prolonged mechanical ventilation. After initiation of a high-protein diet the patient was successfully weaned from the respirator and recovered well. To our knowledge this is the first reported case of adult-onset debrancher deficiency myopathy presenting with subacute respiratory failure and responding to high-protein diet.

Age of Onset↗

PubMed1999

Chorea as the presenting clinical feature of primary antiphospholipid syndrome in childhood.

Three patients, aged five to 16 years, developed chorea as the only or main clinical manifestation of primary antiphospholipid syndrome. In two cases, complaints were self-limited five to eight months after onset. In one patient, the clinical course was complicated by valvulitis. Under corticosteroid treatment, chorea disappeared and cardiac involvement stabilised. Primary antiphospholipid syndrome is a probably under-recognised differential diagnosis of choreatic syndromes in childhood. Assessment of anticardiolipin antibodies and/or lupus anticoagulant should be an obligatory part of the diagnostic work-up of such patients. Early diagnosis of primary antiphospholipid syndrome may improve clinical management and prognosis.

Adolescent↗

PubMed1999

Different clinical aspects of debrancher deficiency myopathy.

OBJECTIVE: To characterise the main clinical phenotypes of debrancher deficiency myopathy and to increase awareness for this probably underdiagnosed disorder. METHODS: The diagnosis of debrancher deficiency was established by laboratory tests, EMG, and muscle and liver biopsy. RESULTS: Four patients with debrancher deficiency myopathy were identified in the Tyrol, a federal state of Austria with half a million inhabitants. Clinical appearance was highly variable. The following phenotypes were differentiated: (1) adult onset distal myopathy; (2) subacute myopathy of the respiratory muscles; (3) severe generalised myopathy; and (4) minimal variant myopathy. Exercise intolerance was uncommon. The clinical course was complicated by advanced liver dysfunction in two patients and by severe cardiomyopathy in one. All had raised creatine kinase concentrations (263 to 810 U/l), myogenic and neurogenic features on EMG, and markedly decreased debrancher enzyme activities in muscle or liver biopsy specimens. The findings were substantiated by a review of 79 previously published cases with neuromuscular debrancher deficiency. CONCLUSIONS: This study illustrates the heterogeneity of neuromuscular manifestations in debrancher deficiency. Based on the clinical appearance, age at onset, and course of disease four phenotypes may be defined which differ in prognosis, frequency of complications, and response to therapy.

Age of Onset↗

PubMed1999

The natural course of atherosclerosis. Part I: incidence and progression.

The natural course of early atherogenesis is not well established. The current prospective survey was designed to monitor 5-year changes in carotid atherosclerosis in a large, stratified random sample of the general population using high-resolution duplex ultrasound (Bruneck Study). Incidence rates of carotid atherosclerosis ranged from near zero to 184 per 1000 person-years. Most atherosclerotic lesions developed at sites with enhanced wall thickness. Incidence of atherosclerosis in premenopausal women was less than half of that observed in men of equal age. The sex difference disappeared within 5 years after menopause and may possibly be attributed to sex variations in body iron stores. Preexisting atherosclerotic lesions may experience 1 of 2 different types of disease progression. 1) The first main type of plaque growth causing nonstenotic or diffuse dilative atherosclerosis was characterized by slow and continuous plaque extension, which usually affected several lesions simultaneously and did not primarily focus on the carotid bifurcation. This step-by-step process relied on a cumulative exposure to well-known risk factors such as hyper-lipidemia. Compensatory enlargement of the artery at the site of active atherosclerosis effectively preserved a (near) normal lumen. 2) The second main type of plaque growth was characterized by occasional prominent increases in lesion size. This process primarily occurred in the internal carotid artery and was mediated by procoagulant risk factors in a way that peak levels were relevant rather than cumulative exposure. As the main underlying pathomechanism, atherothrombosis may be hypothesized. Marked increases in plaque size and insufficient vascular remodeling acted synergistically in producing a significant compromise of the lumen. The current study provides novel insights into the natural course of early carotid atherosclerosis, thereby focusing on disease incidence and various types of spontaneous disease progression. Nonstenotic or diffuse dilating atherosclerosis and focal stenotic disease were found to constitute epidemiologically and etiologically distinct disease entities that develop and proceed independently of each other.

Adult↗

PubMed1999

The natural course of atherosclerosis. Part II: vascular remodeling. Bruneck Study Group.

Arterial remodelling is a potentially important component in atherogenesis aimed at delaying the development of significant lumen compromise. Current knowledge on this phenomenon is mainly restricted to experimental evaluations and a few postmortem studies. We used high-resolution duplex ultrasound to study 5-year changes (1990 to 1995) in vessel geometry in a large random sample of the general population (Bruneck Study). Carotid arteries free of atherosclerosis and wall thickening preserved a normal size to high ages. In contrast, common and internal carotid arteries with elevated intima-media thickness (>/=50th percentile) experienced marked age-dependent dilation that started already in the 5th decade and continuously accelerated thereafter (structural ageing). Vessel diameters were subject to complex regulation involving morphometric characteristics, sex, wall thickness, hypertension, LDL cholesterol levels, and alcohol consumption. Vascular remodelling secondary to incident or slowly progressive (mural) atherosclerosis included local compensation and a generalised dilation response of vascular segments not primarily affected. Adaptive enlargement at the site of active atherogenesis effectively preserved a near-normal lumen in most instances. The current study identified a second main type of plaque growth, characterized by episodic marked increase in lesion volume probably on the basis of plaque thrombosis. In this setting, we did not observe maximum but insufficient compensation but instead usually observed no compensation at all. Failure of vascular remodelling and marked expansion in plaque size acted synergistically in producing significant lumen compromise. The current prospective survey describes fundamental principles and various facets of arterial remodelling and vascular biology in the general population (in vivo). Vessel geometry was subject to marked temporal changes and showed a correspondingly complex (multifactorial) and dynamic regulation. Vascular remodelling emerged as an important compensatory process in human atherogenesis, which crucially contributed to the determination of lumen obstruction. Efficacy and failure of compensation primarily depended on the type and pathomechanisms of underlying atherogenesis and only in second instance on plaque size and location.

Adult↗

PubMed1999

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.

Adult↗

PubMed1998

Sudden infant death syndrome: risk factor profiles for distinct subgroups.

The authors investigated risk profiles of sudden infant death syndrome (SIDS) as a function of age at death. A case-control study carried out in the Tyrol region of Austria enrolled 99 infants who died of SIDS between 1984 and 1994 and 136 randomly selected controls. Early and late SIDS (< 120 days of age vs. > or = 120 days) were defined according to the clear-cut bimodal age-at-death distribution. Inadequate antenatal care, low parental social and educational level, and the prone sleeping position were risk conditions that applied to both early and late SIDS. A marked seasonal variation (winter preponderance) was the most outstanding feature of late SIDS. A gestational age of < 37 weeks (odds ratio (OR) = 8.4, 95% confidence interval (CI) 2.6-26.0), repeated episodes of apnea (OR = 5.7, 95% CI 1.2-27.0), low birth weight (< 2,500 g) (OR = 3.4, 95% CI 1.1-11.0), a family history of sudden infant death (OR = 2.9, 95% CI 1.1-7.5), and maternal smoking during pregnancy (OR = 2.2, 95% CI 1.0-4.5) were associated with early SIDS. This study identified two distinct subgroups of SIDS infants characterized by different risk conditions and ages at death. These results underline a multiple-cause hypothesis for SIDS etiology which involves a genetic predisposition, immaturity in the first months of life, and environmental factors acting at various ages.

Adult↗

PubMed1998

Association of high plasma antioxidant capacity with new lesion formation in carotid atherosclerosis: a prospective study.

BACKGROUND: In atherosclerosis, both reductions and elevations in plasma levels of antioxidants have been reported. This study investigated total antioxidant capacity of plasma from subjects with atherosclerotic disease. MATERIALS AND METHODS: The study population consisted of 48 men with or without carotid atherosclerosis. At baseline (1990) carotid arteries were evaluated by duplex sonography and plasma samples were obtained for testing antioxidant capacity by two different test systems. One assay system used neutrophils from healthy volunteers as a source of oxygen free radicals activating the non-fluorescent dichlorofluorescin diacetate in the presence of antioxidant containing plasma from study subjects. In the other test system, total plasma antioxidants were detected colorimetrically by using 2,2'-azino-di-(3-ethylbenzthiazoline sulphonate), metmyoglobin and superoxide in the presence of plasma. Carotid arteries were re-evaluated for the development of new plaques 5 years later (1995). RESULTS: Increased baseline total antioxidant capacity of plasma was significantly associated with the development of new atherosclerotic lesions during a period of 5 years. CONCLUSIONS: Endogenous antioxidant capacity of plasma is increased in patients with active atherosclerotic disease. As scavenging of oxygen free radicals is thought to protect from atherogenesis, elevated antioxidative capacity may represent an adaptive mechanism.

Adult↗

PubMed1998

Living at high altitude and risk of sudden infant death syndrome.

OBJECTIVE: To investigate the association between altitude of residence and risk of sudden infant death syndrome (SIDS). METHODS: A retrospective, case control study in the Tyrol, Austria enrolled 99 infants with SIDS occurring between 1984 and 1994, and 136 randomly selected control cases. Data on pregnancy, delivery, child care practice, and socio-demographic characteristics including altitude of residence were collected with a standardised questionnaire. RESULTS: The risk of SIDS increased gradually with increasing altitude of residence. This relation remained independently significant when the analysis was adjusted for gestational age, birth weight, prenatal care, mother's age at delivery, educational level of parents, and cigarette smoking during pregnancy. The prone sleeping position emerged as an obligatory cofactor in this association. In the whole of Austria, a similar trend of association emerged between the average altitudes in the 99 political counties and the rates of SIDS. CONCLUSIONS: This study identified altitude of residence as a significant risk predictor of SIDS, primarily in combination with the prone sleeping position. Respiratory disturbances, reduced oxygen saturation, and lower temperatures at high altitude might explain this association.

Altitude↗

PubMed1998

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.

Adult↗

PubMed1998

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.

Adult↗

PubMed1998

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.

Adult↗

PubMed1997

Human and bovine endothelial cell monolayers are differentially activated for neutrophil transmigration by human plasma.

Endothelial cells used in transendothelial migration assays have been derived from different sources including human umbilical vein and bovine pulmonary artery. As plasma-induced activation of endothelial cells for enhanced transmigration of leukocytes may be pathophysiologically relevant, the role of species differences between plasma and endothelial cells was studied. The effects of human plasma on human umbilical vein and bovine pulmonary artery endothelial cells with regard to transmigration of neutrophils were compared. Transendothelial migration of neutrophils was tested employing endothelial cell-covered Transwell cell culture chamber inserts with micropore filters of 5 microns pore size. Results showed that human plasma induces neutrophil transmigration of both human umbilical vein and bovine pulmonary artery endothelial cell monolayers. Plasma samples from 50 to 69 year old men with and without carotid arteriosclerosis (N = 152) stimulated endothelial cells of human origin significantly stronger for transmigration of neutrophils than endothelial cells of bovine origin. Analyses of limits of agreement and of correlation of the two methods indicated that bovine pulmonary artery and human umbilical vein endothelial cells cannot replace each other in assays of plasma-induced activation of transmigration. Plasma levels of soluble adhesion molecule P-selectin, which are elevated in patients with arteriosclerotic diseases, are inversely related to plasma-induced activation of neutrophil transmigration of endothelial monolayers of human origin but not of bovine origin (N = 65). As rates of transmigration that were induced by plasma from subjects without carotid arteriosclerosis (N = 73) were significantly related between human and bovine endothelium, elevated plasma levels of soluble P-selectin may thus affect results of assays for plasma-induced activation of neutrophil transmigration of endothelial monolayers in a species-specific manner.

Adult↗

PubMed1997

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.

Adult↗

PubMed1997

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.

Adult↗

PubMed1997

Pre- and postnatal medical care and risk of sudden infant death syndrome.

The current study investigated whether sufficient attendance at prenatal and postnatal checks affects the risk of sudden infant death syndrome. A case-control study in the Tyrol enrolled 99 infants with sudden infant death syndrome that occurred between 1984 and 1994, and 136 randomly selected control cases. The risk of sudden infant death syndrome was higher in infants whose mothers attended less than five antenatal health checks than in the group with at least five or more visits (OR 5.1; p < 0.01). Babies who received medical help beyond routine health controls had a lower risk than those who did not (OR 0.32; p < 0.001). These differences persisted when social and demographic variables (mother's age at delivery, educational level, marital status, parity and gestational age) were taken into account. Our study identified inadequate antenatal and postnatal care as a risk indicator for sudden infant death syndrome and as a potential target for further educational work. Clinical recommendations should await the results of further evaluations.

Austria↗

PubMed1997

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.

Adult↗

PubMed1996

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).

Adult↗