Autoimmune mechanisms in human vascular disease

Influenza as a trigger for cardiovascular disease: An investigation of serotype, subtype and geographic location

BACKGROUND

Seasonal peaks of influenza and cardiovascular disease tend to coincide. Many excess deaths may be triggered by influenza, and the severity of this effect may vary with the virulence of the circulating influenza strain and host susceptibility. We aimed to explore the association between hospital admissions for influenza and/or pneumonia (IP) and acute myocardial infarction (AMI) or ischaemic heart disease (IHD) in Queensland, Australia, taking into account temporal and spatial variation of influenza virus type and subtype in 2007, 2008 and 2009.

METHODS

This ecological study at Statistical Subdivision level (SSD, n=38) used linked patient-level data. For each study year, Standardized Morbidity Ratios (SMRs) were calculated for hospital admissions with diagnoses of IP, AMI and IHD. We investigated the associations between IP and AMI or IHD using spatial autoregressive modelling, adjusting for socio-demographic factors.

RESULTS

Spatial autocorrelation was detected in SMRs, possibly reflecting underlying social and behavioural risk factors, but consistent with infectious disease spread. SMRs for IP were consistently predictive of SMRs for AMI and IHD when adjusted for socioeconomic status, population density and per cent Indigenous population (coefficient: 0.707, 95% confidence interval (CI): 0.318 - 1.096; 0.553, 0.222 - 0.884; 0.598, 0.307 - 0.888 and 1.017, 0.711 - 1.323; 0.650, 0.342 - 0.958; 1.031, 0.827 - 1.236) in 2007, 2008 and 2009, respectively.

CONCLUSIONS

This ecological study provides further evidence that severe respiratory infections may trigger the onset of cardiovascular events, implicating the influenza virus as a contributing factor.

Myocardial perfusion and intima-media thickness in patients with subclinical hypothyroidism

PURPOSE

The data concerning the relation between subclinical hypothyroidism (SH) and the risk of cardiovascular disease are divergent. We aimed to assess myocardial perfusion in contrast-enhanced echocardiography and intima-media thickness (IMT) in patients with SH.

MATERIAL/METHODS

Forty females with SH without symptoms of coronary artery disease and 15 healthy female volunteers were examined. Echocardiographic evaluation of the left ventricle function as well as carotid and femoral IMT complex measurements were performed at baseline. Thereafter, dobutamine stress echocardiography with myocardial perfusion assessment at rest and on the peak of stress test was performed. SonoVue® intravenous bolus as a contrast medium was used. The myocardial perfusion was assessed by quantitative method using Q-LAB Philips software (ROI modality). The perfusion index was calculated (a number of left ventricle segments with improved perfusion/a number of all segments).

RESULTS

A mean IMT value in the SH group was significantly higher than in the controls (0.7 mm vs. 0.38 mm, p=0.001). Myocardial perfusion at rest and at the peak of stress test was significantly lower in the SH patients as compared to the controls (at rest 120 Db in SH vs. 181 Db in controls, p=0.039 and at the peak of stress 115 Db and 188 Db, p=0.01, respectively). The perfusion index was not significantly worse in the SH group (p=0.6). IMT values negatively correlated with the myocardial perfusion index at the peak of stress (r=-0.54, p=0.014).

CONCLUSIONS

In patients with SH contrast-enhanced echocardiographic examination revealed myocardial hypoperfusion and increased IMT. Our results may suggest that the patients with SH are at risk of the development of cardiovascular disease.

Childhood Morbidity and Health in Early Adulthood: Life course linkages in a high morbidity context

This paper examines whether morbidity in early and later childhood is associated with health later in life. I investigate the relationship between five types of childhood morbidity and risk factors for cardiovascular disease among Guatemalan adults who experienced high levels of morbidity in childhood. The analysis is based on the Human Capital Study (2002-2004), a recent follow-up of the INCAP Longitudinal Study conducted between 1969 and 1977. I find that most types of childhood morbidity are associated with poorer adult health, independent of family background, adult socioeconomic status, and health behaviors. Higher levels of infections in childhood were associated with a low level of high density lipoprotein (HDL), and higher level of triglycerides, plasma glucose, waist circumference, and obesity (but not hypertension). These results are consistent with the literature that finds that childhood morbidity is associated with increased morbidity and mortality at older ages. However, diarrheal disease in later childhood was associated with lower levels of some risk factors, as measured by triglycerides and plasma glucose, suggesting that exposure to bacteria after infancy may be beneficial for some measures of adult health.

Arterial stiffness but not intima-media thickness is increased in euthyroid patients with Hashimoto's thyroiditis: The effect of menopausal status

BACKGROUND

Hashimoto's thyroiditis (HT) is an autoimmune disorder associated with increased cardiovascular risk, mainly as a result of accelerated atherosclerosis. The aim of this study was to determine the effect of HT on carotid atherosclerosis and arterial stiffness, as possible mediators of this vascular impairment. Menopausal status was also considered in this setting since HT is mainly prevalent in women.

METHODS

Fifty-four women with HT and normal thyroid function (thyrotropin [TSH] < 4.5 mU/L) and 72 healthy controls with comparable age and risk factor prevalence were examined in this cross-sectional study. Intima-media thickness (IMT) in the carotid arteries averaged from six sites and carotid-femoral pulse wave velocity (PWV) were measured.

RESULTS

Although both groups had TSH levels within normal limits, TSH was higher in HT patients (2.1 +/- 1.16 vs. 1.5 +/- 0.8 mU/L, p = 0.001). PWV (7.95 +/- 2.02 vs. 7.21 +/- 1.24 m/s, p = 0.021), but not IMT (0.644 +/- 0.144 vs. 0.651 +/- 0.169 mm, p = 0.798), was significantly higher in HT patients compared to controls. When the women were divided according to menopausal status, only premenopausal women without HT had significantly lower PWV when compared with the three other subgroups (6.51 +/- 1.09 m/s premenopausal controls vs. 7.64 +/- 2.05 m/s premenopausal HT vs. 7.69 +/- 1.11 m/s postmenopausal controls vs. 8.3 +/- 1.97 m/s postmenopausal HT, p < 0.001). By multivariate analysis PWV independently correlated with age (p = 0.042), the presence of HT (p = 0.002), TSH (p = 0.003), and menopause (p < 0.001) in the whole population while HT was an independent determinant of PWV only in premenopausal women.

CONCLUSIONS

HT is associated with increased PWV independent of arterial atheromatosis, indicating a direct impact of this disorder on arterial stiffening. This effect may be masked in postmenopausal women possibly due to their heavier cardiovascular risk profile.

Autoantibodies in untreated and treated essential hypertension. I

Using the indirect immunofluorescence method, autoantibodies (AB) of IgG and IgM classes were investigated in sera from 161 consecutive patients with essential hypertension and compared with those from 78 healthy normotensive subjects of the same composition by age and sex, and without any family history of hypertension. The frequency of one or more AB was as high in 78 untreated (15.3%) as in 83 treated patients (13.0%) and was in the controls 9.0% (n.s.). In the treated patients, the AB were associated with heart involvement (p less than 0.02). In the untreated patients, antinuclear antibodies of IgG class were associated with BP (p less than 0.01) and fundus grading (p less than 0.005). A family history of hypertension was found in 23.5% of the hypertensive males with AB and in 9.0% of the normotensive males (p less than 0.10). These results are discussed in relation to reports of an association of AB with cardiovascular diseases. It is concluded that the presence of AB in essential hypertension is not necessarily due to drug induction.

Serum concentrations of immunoglobulins and free light chains before and after vascular events in essential hypertension

Serum concentrations of immunoglobulins (Ig) and free light chains (LC) of Ig have been determined at regular intervals during five years in patients with essential hypertension and correlated to development of vascular complications. In 6 cardiac event patients serum IgG increased by 11.9% (p less than 0.05) and LC by 19.8% (p less than 0.05). IgG levels correlated positively with LC levels (r = 0.59, p less than 0.001) and changes in IgG correlated positively with changes in LC (r = 0.46, p less than 0.01). The post-event increments in IgG persisted up to 21 months. No significant changes in serum concentrations of IgA, IgM, albumin and creatinine were found. In 10 cerebral event patients and in matched groups of 15 uncomplicated hypertensive patients, no significant changes in the above parameters could be demonstrated. It is concluded that heart tissue damage in essential hypertension induces a long-lasting stimulation of B-lymphocytes, and it is suggested that the high Ig levels found in as yet uncomplicated hypertensive patients may reflect an ongoing damage of the vascular bed.

Increased serum levels of immunoglobulins in untreated and treated essential hypertension. I. Relation to blood pressure

In 164 consecutive patients with essential hypertension, serum immunoglobulin (Ig) levels of IgA, IgG, and IgM classes were determined, using single radial diffusion techniques, and compared with 80 healthy normotensive subjects without any family history of hypertension. Of 80 untreated and 84 treated patients, IgA and/or IgG were significantly increased in 40% and 37%, respectively. IgG correlated positively to BP in untreated patients (p less than 0.0008), as well as in insufficienctly treated males (p less than 0.004). No correlations were found between Ig and duration of hypertension. The increase in Ig was not associated with any particular drugs. A family history of hypertension was found in 19.6% of the patients with elevated Ig and in 9.7% of those with normal Ig (p less than 0.10). The study provides further evidence for involvement of immune mechanisms in essential hypertension, and suggests a possible genetic predisposition.

The effect of hormone replacement treatment on thrombin-activatable fibrinolysis inhibitor activity levels in patients with Hashimoto thyroiditis

BACKGROUND

Hypothyroid patients have increased risk of cardiovascular diseases, and several mechanisms have been considered responsible in these patients. Although, a few studies demonstrated fibrinolytic system changes in hypothyroid patients, there is no study demonstrating TAFI activity in hypothyroid Hashimoto's thyroiditis patients. The aim of this study was to evaluate TAFI activity status and the effect of L thyroxin hormone replacement treatment on fibrinolytic system in this patient group.

METHODS

Thirty patients with hypothyroid Hashimoto thyroiditis (all were female and the mean age was 44.3+/-14.6 years, ranging between 17-68 years) were enrolled to study. Their TSH levels were high (27.2+/-5.2 mU/L) and Free T3 and Free T4 hormone levels were below than normal. In this study, euthyroid 20 healthy volunteers (mean age 32.5+/-4.9 years, range 26-42 years) were adopted. L-thyroxin treatment before and after TAFI activity levels were measured in patients.

RESULTS

In the control group, TAFI activity levels were 9.6+/-0.4 microg/mL. In patients with L-thyroxin before and after treatment there were high levels of TAFI activity value of 14.2+/-0.9 and 12.9+/-0.8 microg/mL, respectively. In the patient group, after L-thyroxin treatment TAFI activity levels were decreased but they were not statistically significant (p=0.187). When compared to the control group, high levels of TAFI activity were observed in the patient group (p<0.0001).

CONCLUSION

Our data demonstrated that in Hashimoto thyroiditis, patients have high levels of TAFI activity compared to controls. A high level of TAFI activity suggests fibrinolytic deficit or thrombotic tendency in hypothyroid patients and this deficit is persistent after L-thyroxine replacement.

A survey for circulating immune complexes in patients with acute myocardial infarction. Use of a C1q-binding assay with soluble protein A as indicator

A new assay for the detection of circulating C1q-binding immune complexes (IC) is described. The assay makes use of solid-phase C1q and iodinated soluble protein A, extracted from the cell wall of Staphylococcus aureus. In a model system the assay could detect heat-aggregated IgG down to a concentration of about 50 ng/ml. This method and three other assays, previously described, were used to survey the appearance of IC activity in sera from hospitalized patients with acute myocardial infarction. Depending on the assay system used, from 56% to 66% of the patients investigated were found to develop circulating IC. The earliest appearance of circulating IC was noted 5 days after infarction. The highest incidence of positive reactions and the strongest reactions occurred 2 to 3 weeks after hospitalization; thereafter the IC positiveness tapered off, and all patients were negative 6 weeks after infarction.

The association of childhood socioeconomic conditions with healthy longevity at the oldest-old ages in China

Based on unique data from the largest-ever sample of the Chinese oldest-old aged 80 and older, our multivariate logistic regression analyses show that either receiving adequate medical service during sickness in childhood or never/rarely suffering from serious illness during childhood significantly reduces the risk of being ADL (activities of daily living) impaired, being cognitively impaired, and self-reporting poor health by 18%-33% at the oldest-old ages. Estimates of effects for five other indicators of childhood conditions are similarly positive but mostly not statistically significant. Multivariate survival analysis shows that better childhood socioeconomic conditions in general tend to reduce the four-year period mortality risk among the oldest-old. But after additional controls for 14 covariates are put into the model, the effects are not statistically significant, thus suggesting that most of the effects of childhood conditions on oldest-old mortality are indirect-at least to the point of affecting current health status at the oldest-old ages, which itself is strongly associated with mortality. While acknowledging limitations of the present analyses due to a lack of information on childhood illness, the oldest-olds'recollection errors, and other data problems, we conclude, based on this and other studies, that policies that enhance childhood health care and children's socioeconomic well-being can have large and long-lasting benefits up to the oldest-old ages.

Impact of subclinical thyroid disorders on coronary heart disease, cardiovascular and all-cause mortality: a meta-analysis

BACKGROUND

Previous studies have suggested that sub-clinical thyroid states may have detrimental effects on the coronary heart disease (CHD). Whether subclinical thyroid dysfunction is a risk factor for the above is controversial.

METHODS

A systemic search of the literature using Pubmed, Medline and Ovid online tool was performed to identify relevant studies. Amongst the clinical studies, crossectional study and studies with follow-up period ranging between 4 and 20 yr were identified (Walsh JP, Bremner AP, Bulsara MK, et al. Subclinical thyroid dysfunction as a risk factor for cardiovascular disease. Arch Intern Med 2005 Nov 28;165 (21):2467-72.; Rodondi N, Newman AB, Vittinghoff E, et al. Subclinical hypothyroidism and the risk of heart failure, other cardiovascular events, and death. Arch Intern Med 2005 Nov 28; 165 (21):2460-6.; Rotterdam study, Imaizumi M, Akahoshi M, Ichimaru S, et al. Risk for coronary heart disease and all-cause mortality in subclinical hypothyroidism. J Clin Endocrinol Metab 2004 Jul; 89 (7):3365-70.; Capolla et al.; Parle JV, Maisonneuve P, Sheppard MC, Boyle P, Franklyn JA. Prediction of all-cause and cardiovascular mortality in elderly people from one low serum thyrotropin result: a 10-year cohort study. Lancet 2001 Sep 15; 358 (9285):861-5).

RESULTS

Sub-clinical hypothyroidism: The pooled estimate of the relative risk of CHD revealed significant difference both at baseline [RR with 95% CI: 1.533 (1.312-1.791), P<0.05] and at follow-up [RR with 95% CI: 1.188 (1.024-1.379), P<0.05]. The relative risk of all-cause mortality at follow-up revealed no significant difference. However, the relative risk of death from cardiovascular causes at follow-up was significantly higher [RR with 95% CI: 1.278 (1.023-1.597), P<0.05]. Sub-clinical hyperthyroidism: The pooled estimate of the relative risk of CHD revealed no significant difference both at baseline [RR with 95% CI: 1.156 (0.709-1.883)] and at follow-up [RR with 95% CI: 1.207 (0.780-1.870)].The relative risk of death from cardiovascular causes at follow-up was also not significantly higher.

CONCLUSION

The present meta-analysis indicates that sub-clinical hypothyroidism is associated with both, a significant risk of CHD at baseline and at follow-up. In addition, mortality from cardiovascular causes is significantly higher at follow-up. Sub-clinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes.

Early-life origins of the race gap in men's mortality

Using a life course framework, we examine the early life origins of the race gap in men's all-cause mortality. Using the National Longitudinal Survey of Older Men (1966-1990), we evaluate major social pathways by which early life conditions differentiate the mortality experiences of blacks and whites. Our findings indicate that early life socioeconomic conditions, particularly parental occupation and family structure, explain part of the race gap in mortality. Black men's higher rates of death are associated with lower socioeconomic standing in early life and living in homes lacking both biological parents. However these effects operate indirectly through adult socioeconomic achievement processes, as education, family income, wealth, and occupational complexity statistically account for the race gap in men's mortality. Our findings suggest that policy interventions to eliminate race disparities in mortality and health should address both childhood and adult socioeconomic conditions.

Abnormal endothelial function in female patients with hypothyroidism and borderline thyroid function

BACKGROUND

It has been suggested that hypothyroidism is associated with an increased risk for cardiovascular disease. The aim of this study was to assess non-invasively NO-dependent endothelial function of resistance arteries in subjects with hypothyroidism of varying severity.

METHODS

Ninety-six female subjects (aged: 42+/-13 years) comprised the study population. Subjects were divided into five groups based on TSH levels at presentation: Group 0 (n=23) with TSH: 0.3-2.0 microU/ml, Group 1 (n=22) with TSH: 2.1-4.0 microU/ml (upper normal), Group 2 (n=18) with TSH: 4.1-10 microU/ml (subclinical hypothyroidism), Group 3 (n=22) with TSH >10 microU/ml (overt hypothyroidism). One additional group with well-controlled hypothyroidism on L-thyroxine therapy (Group 4, n=11, TSH: 0.3-2.0 microU/ml) was also studied. Endothelial function of resistance arteries was assessed by measuring forearm blood flow response during reactive hyperemia utilizing venous occlusion strain-gauge plethysmography.

RESULTS

Duration of reactive hyperemia was significantly different among groups of subjects with varying hypothyroidism (83.7+/-58.3 s, 53.2+/-35.7 s, 52.8+/-47.5 s, 12.9+/-13.3 s and 69.5+/-26.2 s in Groups 0, 1, 2, 3 and 4, respectively, p<0.001, ANOVA). Duration of reactive hyperemia was significantly shorter in subjects with upper normal TSH values (Group 1) compared to controls (53.2+/-35.7 s vs. 83.7+/-58.3 s, p=0.013), while it was comparable to that of subjects with subclinical hypothyroidism (Group 2) (52.8+/-47.5 s). However, duration of reactive hyperemia in Group 1 was significantly longer compared to Group 3 (overt hypothyroidism) (53.2+/-35.7 s vs. 12.9+/-13.3 s, p=0.002). Similarly, duration of reactive hyperemia in subjects with subclinical hypothyroidism was significantly longer compared to subjects with overt hypothyroidism (52.8+/-47.5 s vs. 12.9+/-13.3 s, p=0.003). Duration of reactive hyperemia in Group 4 (well-controlled hypothyroidism on L-thyroxine therapy) did not differ significantly compared to controls. There was a highly significant linear correlation between duration of reactive hyperemia and TSH (r=-0.383, p<0.001).

CONCLUSION

Endothelial dysfunction was detected in the microvasculature of patients with hypothyroidism. Duration of reactive hyperemia decreased with increasing TSH levels. Since endothelial dysfunction is a factor leading to atherosclerosis, this abnormality may partly explain predisposition of patients with thyroid failure to cardiovascular disease.

Impairment of endothelium-dependent arterial dilation in Hashimoto's thyroiditis patients with euthyroidism

OBJECTIVE

Recent studies have shown that immune responses contribute to atherosclerosis, and endothelial dysfunction is an important early event in atherogenesis. The aim of this study was to investigate the alteration of endothelial function in Hashimoto's thyroiditis (HT) patients with euthyroidism.

METHODS

Study subjects included 28 female HT patients with euthyroidism, 23 female HT patients with hypothyroidism, and 22 healthy women. High-resolution ultrasound was used to measure brachial artery diameter at rest, after reactive hyperaemia and after sublingual glyceryltrinitrate (GTN).

RESULTS

Flow-mediated arterial dilation in HT patients with euthyroidism was significantly lower (3.88%) than in controls (4.98%, P = 0.000) and higher than in HT patients with hypothyroidism (3.26%, P < 0.001). Flow-mediated arterial dilation among HT patients with hypothyroidism was significantly lower than that in controls (P = 0.000). GTN-induced arterial dilation, baseline vessel size, and baseline blood flow were not significantly different among the three groups (P > 0.05). On multiple regression analysis, anti-thyroid peroxidase antibody (TPO-Ab), TSH, free T3, low density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] were found to be significant factors associated with endothelium-dependent arterial dilation.

CONCLUSION

Endothelial dysfunction exists in HT patients with euthyroidism. Autoimmune reactivity and an elevated Lp(a) level might be responsible for the endothelial dysfunction.

The long arm of childhood: The influence of early-life social conditions on men’s mortality

Increasingly, social scientists are turning to childhood to gain a better understanding of the fundamental social causes of adult mortality. However, evidence of the link between childhood and the mortality of adults is fragmentary, and the intervening mechanisms remain unclear. Drawing on the National Longitudinal Survey of Older Men, our analysis shows that men’s mortality is associated with an array of childhood conditions, including socioeconomic status, family living arrangements, mother’s work status, rural residence, and parents’ nativity. With the exception of parental nativity, socioeconomic-achievement processes in adulthood and lifestyle factors mediated these associations. Education, family income, household wealth, and occupation mediated the influence of socioeconomic status in childhood. Adult lifestyle factors, particularly body mass, mediated the effects of family living arrangements in childhood, mother’s work status, and rural residence. Our findings bring into sharp focus the idea that economic and educational policies that are targeted at children’s well-being are implicitly health policies with effects that reach far into the adult life course.

SW. Thyroid dysfunction and their relation to cardiovascular risk factors such as lipid profile, hsCRP, and waist hip ratio in Korea

BACKGROUND

Thyroid abnormalities affect a considerable portion of the population, and overt hypothyroidism is associated with an elevated risk of cardiovascular disease and adverse changes in blood lipids. Subclinical hypothyroidism is also associated with an increase risk of cardiovascular disease. So, we undertook this study to investigate the prevalence of overt and subclinical thyroid disorders and their associations with cardiovascular risk factors.

METHODS

This study involved 66,260 subjects (43,588 men, 22,672 women; between 20-80 years of age, mean age 41.5 +/- 9.6). Serum free thyroxine (FT4), thyroid stimulating hormone (TSH), total cholesterol, low density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C) were measured by RIA using commercial kits. High sensitivity C-reactive protein (hsCRP) levels were determined by nephelometry.

RESULTS

The prevalences of overt thyrotoxicosis, subclinical thyrotoxicosis, overt hypothyroidism and subclinical hypothyroidism were 5/1000 (334 subjects), 6.4/1000 (426 subjects), 1.6/1000 (108 subjects), and 6.4/1000 (375 subjects). Mean plasma total cholesterol and LDL-C were elevated in overt hypothyroidism than in normal controls (202.1 mg/dL and 121.8 mg/dL versus 197.1 mg/dL and 120.1 mg/dL, respectively) (p < 0.05). In subclinical hypothyroidism, mean total cholesterol and LDL-C levels were also elevated (201.9 mg/dL and 123.7 mg/dL) (p = 0.015, p = 0.047). Waist-to-hip ratio (WHR) was lower in overt thyrotoxicosis and higher in hypothyroidism.

CONCLUSION

The prevalence of thyroid dysfunction in Korea is not significantly different from that reported by other countries. It was also age dependent and higher in women, but this elevation in women was lower than expected. Patients with hypothyroidism exhibited higher waist-to-hip ratios, an index of obesity. Patients with subclinical hypothyroidism exhibited elevated atherogenic parameters (Total cholesterol, LDL-C). Therefore screening and treatment for subclinical hypothyroidism may be warranted due to its adverse effects on lipid metabolism.

Impaired endothelium-dependent vasodilatation in subclinical hypothyroidism: beneficial effect of levothyroxine therapy

Subclinical hypothyroidism (sHT) is associated with enhanced cardiovascular risk. To test the hypothesis that patients with sHT are characterized by endothelial dysfunction and impaired nitric oxide (NO) availability, in 14 patients [serum cholesterol, 218 +/- 41 mg/dl (5.6 +/- 0.9 mM)] and 28 euthyroid subjects, subdivided into groups A and B [serum cholesterol, 170 +/- 19 mg/dl (4.4 +/- 0.5 mM) and 217 +/- 21 mg/dl (5.6 +/- 0.5 mM), respectively], we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine, an endothelium-dependent vasodilator, at baseline and during infusion of N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor. Response to sodium nitroprusside and minimal forearm vascular resistances were also evaluated. In sHT patients, vasodilation to acetylcholine was reduced, compared with group B (+358 +/- 29% vs. +503 +/- 19%, P = 0.0003) and group A (663 +/- 65%, P = 0.02 vs. group B and P = 0.0002 vs. sHT). L-NMMA blunted the vasodilation to acetylcholine in groups A and B (49.1 +/- 6.3% and 42.7 +/- 5.5% maximal forearm blood flow reduction, respectively, P < 0.0001 vs. acetylcholine), whereas it was ineffective in sHT patients (12.8 +/- 2.5%). Response to sodium nitroprusside and minimal vascular resistances were similar. In sHT (n = 9) patients, 6 months of euthyroidism by levothyroxine replacement increased acetylcholine-vasodilation and restored L-NMMA inhibition. Patients with sHT are characterized by endothelial dysfunction resulting from a reduction in NO availability, an alteration partially independent of dyslipidemia and reversed by levothyroxine supplementation.

Does childhood health affect chronic morbidity in later life?

Our analysis examines whether childhood health has long-term and enduring consequences for chronic morbidity. As a part of this analysis, we address two methodological issues of concern in the literature. Is adult height a surrogate for childhood health experiences in modeling chronic disease in later life? And, are the effects of adult socioeconomic status on chronic disease overestimated when childhood health is not accounted for? The analysis is based on a topical module to the third wave of the Health and Retirement Study, a representative survey of Americans aged 55-65 in 1996. Our results support the hypothesis that poor childhood health increases morbidity in later life. This association was found for cancer, lung disease, cardiovascular conditions, and arthritis/rheumatism. The associations were highly persistent in the face of statistical controls for both adult and childhood socioeconomic status. No support was found for using adult height as a proxy for the effects of childhood health experiences. Further, the effects of adult socioeconomic status were not overestimated when childhood health was excluded from the explanatory models. Our results point to the importance of an integrated health care policy based on the premise of maximizing health over the entire life cycle.

Subclinical hypothyroidism is an independent risk factor for atherosclerosis and myocardial infarction in elderly women: the Rotterdam Study

BACKGROUND

Overt hypothyroidism has been found to be associated with cardiovascular disease. Whether subclinical hypothyroidism and thyroid autoimmunity are also risk factors for cardiovascular disease is controversial.

OBJECTIVE

To investigate whether subclinical hypothyroidism and thyroid autoimmunity are associated with aortic atherosclerosis and myocardial infarction in postmenopausal women.

DESIGN

Population-based cross-sectional study.

SETTING

A district of Rotterdam, The Netherlands.

PARTICIPANTS

Random sample of 1149 women (mean age +/- SD, 69.0 +/- 7.5 years) participating in the Rotterdam Study.

MEASUREMENTS

Data on thyroid status, aortic atherosclerosis, and history of myocardial infarction were obtained at baseline. Subclinical hypothyroidism was defined as an elevated thyroid-stimulating hormone level (>4.0 mU/L) and a normal serum free thyroxine level (11 to 25 pmol/L [0.9 to 1.9 ng/dL]). In tests for antibodies to thyroid peroxidase, a serum level greater than 10 IU/mL was considered a positive result.

RESULTS

Subclinical hypothyroidism was present in 10.8% of participants and was associated with a greater age-adjusted prevalence of aortic atherosclerosis (odds ratio, 1.7 [95% CI, 1.1 to 2.6]) and myocardial infarction (odds ratio, 2.3 [CI, 1.3 to 4.0]). Additional adjustment for body mass index, total and high-density lipoprotein cholesterol level, blood pressure, and smoking status, as well as exclusion of women who took beta-blockers, did not affect these estimates. Associations were slightly stronger in women who had subclinical hypothyroidism and antibodies to thyroid peroxidase (odds ratio for aortic atherosclerosis, 1.9 [CI, 1.1 to 3.6]; odds ratio for myocardial infarction, 3.1 [CI, 1.5 to 6.3]). No association was found between thyroid autoimmunity itself and cardiovascular disease. The population attributable risk percentage for subclinical hypothyroidism associated with myocardial infarction was within the range of that for known major risk factors for cardiovascular disease.

CONCLUSION

Subclinical hypothyroidism is a strong indicator of risk for atherosclerosis and myocardial infarction in elderly women.

HLA*A2 confers mortality risk for cardiovascular disease in Pimans

A sample of 1465 full heritage Piman Indians from Arizona were typed for the serological antigens of the HLA class I loci and then incorporated into a survival study that ended December 31, 1991. The total follow-up time was 11,749 person-years with an average of 8.0 years per person. During the study 298 persons died, 54 from cardiovascular disease (CVD). Allele HLA*A2 conferred a 4.94 fold rate for death from CVD (95% C.I. 1.91-12.77). When controlled for the potential confounding variables, cholesterol, mean blood pressure, smoking, body mass index, rheumatoid factor titer, and nephropathy, the mortality rate ratio (MRR) was 5.42 (95% C.I. 1.98-14.82). There was no statistically significant association of mortality with other HLA-A or HLA-B alleles, or for causes of death not related to cardiovascular disease.

The possible roles of sperm and sperm antibodies in the pathogenesis and treatment of AIDS

Intravenous injections of donor sperm may possibly be of value to AIDS patients. The immunological basis for this proposal is reviewed in detail. Donor sperm introduced into the blood of a healthy patient produces anti-sperm antibodies which may become attached to the T-cells and cause their depletion. Reintroduction of donor sperm into the blood of an AIDS patient may reverse the pathogenesis by the donor sperm combining with anti-sperm antibodies so allowing the T-cells to recover. HIV is just the most common among the occupational viral infections of AIDS patients. A clinical trial is proposed.

Immunologic changes after blood transfusion in patients undergoing vascular surgery

Immunologic changes after blood transfusions cannot be studied ethically in normal individuals. We therefore studied two comparable groups of patients with atherosclerotic cardiovascular disease who received similar drug treatment and experienced a similar degree of surgical trauma, except that one group received an average of 2.5 units of packed red cells at one time period during surgery. We conducted immunologic tests preoperatively and 5, 10, 45 to 60, 90, 180, and 360 days postoperatively. There was no significant difference in all indices tested preoperatively between the two groups. Five and 10 days postoperatively, the absolute numbers of CD3, CD4, CD8, and B cells decreased in both groups; however, the decrease was significantly greater in the transfused group than in the nontransfused group 5 days postoperatively. There was no significant difference in these parameters between the two groups at other time periods tested. At 5 and 10 days postoperatively, the lymphocyte responses to phytohemagglutinin, concanavalin A, and allogeneic lymphocytes in autologous serum were decreased in both groups. However, at 60 days postoperatively, the responses of the nontransfused group became significantly increased, whereas those of the transfused group remained relatively unchanged. By days 90, 180, and 360, the lymphocyte responses of the nontransfused group had dropped to levels seen at earlier time intervals and were comparable to responses in the transfused group. There were no significant differences between the groups in the number of T-cell colonies formed, the number of immunoglobulin-producing cells obtained, and the lymphokine responses (migration inhibitory factor/migration stimulation factor) at all times tested. The major immunologic perturbations attributed to blood transfusions were an exaggerated decrease in the numbers of circulating lymphocytes, particularly those with markers associated with T-helper cells, and failure to demonstrate a rebound increase in the proliferative response 45 to 90 days later.

Circulating immune complex studies on patients with oral lichen planus

To investigate the role of systemic factors such as age, diabetes, and hypertension in the formation of subepithelial immune deposits in oral lichen planus (OLP) we performed circulating immune complex CIC determinations by polyethylene glycol precipitation in sera of patients with OLP, diabetes mellitus, and hypertension and in sera of healthy control subjects. We examined patients with leukoplakia as a control group with oral keratosis but no OLP. Forty percent of the OLP patients were suffering from diabetes, hypertension, or both. The occurrence of CIC positivity was higher in the OLP group with diabetes than in the group with OLP only. However, we could not find CIC positivity in our control patients with diabetes. The almost equal distribution of hypertension among, patients with OLP who tested positive for CIC and those who tested negative does not seem to support the hypothesis that this factor causes the CIC positivity in OLP. The same applies to other assumed factors such as age, medication, dental foci, or metal framework. In summary, we support the idea that CIC positivity may be the consequence of lichen itself, but diabetes and hypertension contribute to the development of erosive OLP lesions.

Etiologic factors in renovascular fibromuscular dysplasia. A case-control study

The role of several factors that have been suggested as being of etiologic importance in renovascular fibromuscular dysplasia was examined in a case-control study of 33 patients with angiographically demonstrated fibromuscular dysplasia and 61 renal transplant donor control subjects with normal renal arteries. The factors studied included use of oral contraceptive agents or markers of sex hormone dysfunction, mechanical stress to the renal artery wall, human lymphocytic antigen (HLA) type, cigarette smoking, history of hypertension for more than 5 years, and family history of cardiovascular disease. The risk of fibromuscular dysplasia was significantly (p = 0.003) increased (odds ratio = 4.1, 95% confidence interval = 1.5-10.9) among cigarette smokers. A significant (p less than 0.001) dose-response relation was noted between cigarette use and the risk of fibromuscular dysplasia developing (odds ratio = 8.6 for those who had smoked more than 10 pack-years). Personal history of hypertension more than 5 years was also associated (odds ratio = 5.0, 95% confidence interval = 1.1-22.8) with a significantly (p = 0.036) increased risk for the development of fibromuscular dysplasia. HLA-DRw6 antigen was more common in the 33 fibromuscular dysplasia patients than in the 61 renal transplant donor control subjects (odds ratio = 3.00, p = 0.067) or a second group of 934 ambulatory control subjects (odds ratio = 2.51, p = 0.031). Adjustment for cigarette smoking increased the odds ratio to 5.0 (95% confidence interval = 1.3-19.6). There was a positive though not statistically significant (odds ratio = 1.7, p = 0.175) association noted between family history of cardiovascular disease and fibromuscular dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental infections in association with cerebral infarction in young and middle-aged men

The association between dental infections and cerebral infarction was investigated in a case-control study involving 40 patients with ischaemic cerebral infarction under the age of 50, and 40 randomly selected community controls matched for sex and age. Poor oral health, as assessed by two indices measuring the severity of infections of teeth and periodontium, or by the presence of subgingival calculus or the presence of suppuration in the gingival pockets, were more common in male patients than in male controls, but no difference was observed in females. If severe dental infections were combined with other probable bacterial infections there were altogether 16 patients (40%) but only two controls (5%) who had suffered from a probable bacterial infection within 1 month or at the time of the stroke or when examined as a control (P less than 0.01). Our results suggest an association between bacterial infection and ischaemic cerebrovascular disease in patients under 50 years of age. Severe chronic dental infection seems to be an important type of infection associated with cerebral infarction in males.

Low density lipoprotein metabolism by human macrophages activated with low density lipoprotein immune complexes. A possible mechanism of foam cell formation

Human macrophages play a key role in atherogenesis and are believed to be the progenitors of the cholesteryl ester (CE)-laden foam cells present in early atherosclerotic lesions. Several mechanisms by which macrophages accumulate CE have been recently described. One involves a perturbation in LDL metabolism subsequent to macrophage activation. Thus, we decided to study the effect of macrophage activation by immune complexes on N-LDL metabolism. Initially, LDL-containing immune complexes (LDL-IC) were chosen, since increased plasma levels of these IC have been reported in patients with coronary heart disease. Human macrophages stimulated for 22 h with LDL-IC (250 micrograms/ml) and incubated afterwards for 20 h with 10 micrograms/ml 125I-N-LDL showed a six- and fourfold increase in the accumulation and degradation, respectively, of 125I-N-LDL over the values observed in nonstimulated cells. Scatchard analysis of 125I-N-LDL-specific binding suggests an increase (20-fold) in the number of LDL receptors in macrophages stimulated with LDL-IC. We studied other immune complexes varying in size and antigen composition. Some of the IC were able to stimulate, although to a lesser degree, the uptake of N-LDL by macrophages. Lipoprotein IC are more efficient and have the greatest capacity to increase N-LDL uptake and CE accumulation. We conclude that human macrophage activation by LDL-IC leads to an increase in LDL receptor activity and promotes in vitro foam cell formation.

Preceding infection as an important risk factor for ischaemic brain infarction in young and middle aged patients

The role of preceding infection as a risk factor for ischaemic stroke was investigated in a case-control study of 54 consecutive patients under 50 years of age with brain infarction and 54 randomly selected controls from the community matched for sex and age. Information about previous illnesses, smoking, consumption of alcohol, and use of drugs was taken. A blood sample was analysed for standard biochemical variables and serum cholesterol, high density lipoprotein cholesterol, triglyceride, and fasting blood glucose concentrations determined. Titres of antimicrobial antibodies against various bacteria, including Staphylococcus, Streptococcus, Yersinia, and Salmonella and several viruses were determined. Febrile infection was found in patients during the month before the brain infarction significantly more often than in controls one month before their examination (19 patients v three controls; estimated relative risk 9.0 (95% confidence interval 2.2 to 80.0)). The most common preceding febrile infection was respiratory infection (80%). Infections preceding brain infarction were mostly of bacterial origin based on cultural, serological, and clinical data. In conditional logistic regression analysis for matched pairs the effect of preceding febrile infection remained significant (estimated relative risk 14.5 (95% confidence interval 1.9 to 112.3)) when tested with triglyceride concentration, hypertension, smoking, and preceding intoxication with alcohol. Although causality cannot be inferred from these data and plausible underlying mechanisms remain undetermined, preceding febrile infection may play an important part in the development of brain infarction in young and middle aged patients.

The C3-F gene in patients with intracranial saccular aneurysms

The C3-F gene has previously been found associated with atherosclerotic vascular diseases. The occurrence of the C3-F gene was therefore investigated in a group of 110 hospitalized patients with intracranial saccular aneurysms. The C3-F gene occurred equally often in patients and controls. In patients with a ruptured aneurysm, however, the C3-F gene frequency was significantly increased in subjects aged 40-49 years followed by a marked and statistically significant decline with increasing age. The findings suggest that the C3-F gene may be a risk factor for early aneurysm rupture.

Characterization of circulating immune complexes in heart disease

Circulating immune complexes (CIC) were characterized for the content in IgG, IgA, IgM, C3 and C4 in patients with heart disease. The levels of IgG, IgM and C4 in PEG-precipitates of patients' sera were significantly higher than those found in controls, and the precipitation profile was similar to that of rheumatoid arthritis patients. Differences were observed in the composition of CIC: IgM was highest in association with myocarditis, and C3 predominated in cases of valvular disease. Complex-bound C4 was significantly higher in patients with myocardial infarction which developed pericarditis either early or late in the evolution of the disorder. Antimyocardial antibodies could be detected in sera and in corresponding PEG-precipitates. The bulk of the data suggests that CIC might play a pathogenetic role in various heart diseases.

Vascular changes in human leishmaniasis: a light microscope and immunohistological study

The study of human cutaneous leishmaniasis from Saudi Arabia (37 cases), and of Sudanese mucosal (52 cases) and visceral (27 cases) leishmaniasis revealed the occurrence of vascular alterations. Vasculitis with or without fibrinoid necrosis and fibrin thrombi were found in both the arteries and veins within the area of inflammation in cutaneous and mucosal leishmaniasis; whereas subendothelial oedema, hyalinosis and intimaproliferation were seen in the small arteries of the various organs in visceral leishmaniasis. Immunoperoxidase staining of the cutaneous leishmaniasis lesions showed the presence of IgG and IgA within the endothelial cells, in the media, and in the perivascular space of the diseased vessels. The formation of immune complexes, locally in cutaneous and mucosal leishmaniasis and circulating in visceral leishmaniasis, is considered responsible for these vascular lesions.

Antibodies to cardiolipin in young survivors of myocardial infarction: an association with recurrent cardiovascular events

Antibodies to cardiolipin were measured in 62 survivors of myocardial infarction under age 45 at 3, 12, and 36 months after the acute event. 13 patients (21%) had raised anticardiolipin antibody levels on at least two of the three sampling occasions. Risk-factor profiles and coronary angiographic findings did not differ between the anticardiolipin-positive group and the rest of the patients. No correlation was found between cardiolipin and anti-DNA antibody levels. 8 of the 13 patients with raised anticardiolipin antibody levels experienced additional cardiovascular events during a follow-up of 36-64 months after the first myocardial infarction: cerebral infarction developed in 2, arterial occlusion of the lower limb in 2, new myocardial infarction in 3, pulmonary emboli in 1, and deep-vein thrombosis in 1. These 8 patients had cardiolipin antibody titres of 5 times the mean for voluntary blood donors. Antibodies to cardiolipin are common in young post-infarction patients and should be interpreted as markers of high risk for recurrent cardiovascular events.

Association between post-pericardiotomy syndrome and coronary occlusion after aortic valve replacement

Fever, leucocytosis, and pericardial and pleural effusions developed after the first postoperative week in a 56 year old man who had undergone aortic valve replacement. Four months later, coronary angiography showed bilateral proximal stenosis of the coronary arteries. In this patient post-pericardiotomy syndrome and subsequent coronary artery stenosis were thought to be associated and an immunological mechanism was suspected.

Increased serum IgG levels in essential hypertension

Serum IgG levels were significantly increased (P less than 0.001) in 33 (20 male and 13 female) essential hypertensive cases (mean = 2083.87 +/- 99.94 mg/dl) when compared to 30 (15 male and 15 female) random normotensive control subjects (mean = 993.84 +/- 72.25 mg/dl). Of the 33 cases, 12 (36.3%) were familial and the rest were sporadic. No significant difference was observed in the IgG levels between familial and sporadic cases. Similarly, no significant difference was found between male and female hypertensive patients both in the familial and the sporadic group or between smokers and non-smokers. However, the levels of IgG were found to be increased in the initial stages of onset of the condition (duration of less than 1 yr). The present study supports the probable involvement of immunological responses in essential hypertension.

Genetic analysis of systolic blood pressure in Melbourne families

1. Circumstantial evidence suggests that immunological mechanisms might contribute to hypertension in man. If so, it would be expected that those genetic loci which influence the human immune response would also influence the risk of hypertension. 2. To test this hypothesis, the distribution of systolic blood pressure (SBP) was studied in seventy-eight families comprising 437 adults ascertained through fifty-eight probands with hypertension and twenty probands with low to normal levels of blood pressure. After allowing for the method of ascertainment of the families, and adjusting for the effects of age and sex, about 55% of the phenotypic variance of SBP could be attributed to genetic factors including 23% (42% of the additive genetic variance) attributable to the effects of immunogenetic loci (HLA and Gm). 3. This suggests that relatives with a greater number of HLA and Gm haplotypes in common had more similar SBP levels than similar relatives with fewer HLA and Gm haplotypes in common. This finding supports the hypothesis that immunological mechanisms contribute to hypertension in man.

Infant diarrhoea and subsequent mortality from heart disease and cancer

A preliminary examination of the relationship between the infant mortality of US birth cohorts and their mortality in later life suggested that infant mortality from diarrhoea and enteritis was particularly influential. In the 1917-21 birth cohorts of 17 US Registration States, infant mortality from diarrhoea and enteritis was significantly related to arteriosclerosis heart disease at ages 40-44 and 50-54 in both sexes, and to respiratory cancer at the same ages in men, after controlling for contemporary infant mortality. Hypotheses suggest by these relationships are put forward.

Immune complexes and vasoactivity generated from platelets in pre-eclampsia

In vivo platelet activation by circulating immune complexes has been suggested as one of the underlying mechanisms in preeclampsia. Using a modification of the polyethylene glycol protein-A immune complex assay, immune complexes were found in excess of the equivalent of 20 micrograms/ml heat aggregated IgG in fourteen out of twenty patients diagnosed as having pre-eclampsia. Only six out of nineteen normal controls were found to have similar levels of immune complexes. Furthermore, using a small volume bio-assay method, concentrations of heat aggregated IgG in excess of 20 micrograms/ml were found to activate platelets to release sufficient concentrations of vasoactive agents to constrict a human blood vessel in vitro. These results support the hypothesis that in vivo platelet activation by immune complexes can release sufficient concentrations of vasoactive agents to contribute to the hypertension characteristic of pre-eclampsia.

Serial measurement of circulating immune complexes in myocardial infarction

To study the changes in the quantity of circulating immune complexes in myocardial infarction two serial investigations were performed in 45 and 63 patients, respectively. For the detection of circulating immune complexes in the first series, two methods, a complement consumption test and a Clq-solubility test were used. In the second series, a polyethylene glycol (PEG)-precipitation assay was added to these methods. The incidence of circulating immune complexes was studied on the first, third, seventh, 14th, and 21st day. On the first day the complexes were detected in 59% of the patients. Their occurrence increased in the further samplings to 77%, but from the seventh day their concentration decreased and on the 21st day they were detected in 63%. Three types of changes in the level of circulating immune complexes could be shown. In type I immune complexes were detected in the first days after the onset of the infarction, then, after a gradual decrease, the results became negative. In type II immune complexes appeared in the second to third week and their quantity did not alter during the entire observation period. In type III the circulating immune complexes could be detected throughout the whole period of the study. These changes in their concentration were frequently associated with the clinical course of the disease.

Different blood pressure response to DOCA-NaCl treatment in autoimmune and N,N'- diacetylbenzidine-induced nephropathies

In order to explore the effect of immunologically-induced nephropathy versus a non-immunological model on development of hypertension, rats with either Heymann nephritis or N,N'-diacetylbenzidine (N,N'-DAB)-induced nephropathy were subjected to DOCA-NaCl treatment. Hypertension developed during DOCA-NaCl treatment in Heymann nephritic rats but not in rats wih N, N'-DAB nephropathy, despite similar degrees of proteinuria and other features of nephrosis. There were no signs of different fluid balance, either. Azotemia did not ensue. Histology and immunohistology showed membranous glomerulonephritis in Heymann nephritic rats whereas glomerular epithelial cell alterations without immune deposits along the glomerular capillary walls were seen in rats with N, N'-DAB nephropathy. The type of renal damage or factors mediating such damage appear to be important determinants for the hypertensive response of Heymann nephritic rats to DOCA-NaCl treatment.

Characterization of immunological depression in spontaneously hypertensive rats

Immunocompetent cell functions were evaluated in spontaneously hypertensive rats (SHR). Hematological studies revealed decreased absolute numbers of lymphocytes and increases number of polynucleic cells in the peripheral blood of SHR. The SHR had a reduced number of immature T lymphocytes in their thymuses in comparison with an original strain of Wistar rats, as detected by the rosette formation test with guinea pig erythrocytes. The antibody response to sheep red blood cells (SRBC) of the 3-month-old SHR was profoundly depressed and was about one-teeth that of the Wistar rats. Cell cooperation experiments suggest that the T lymphocytes of the SHR were selectively impaired in antibody responses to SRBC in cooperation with B lymphocytes. B lymphocytes from the bone marrow of the SHR were not affected and produced normal numbers of plaque-forming units. Cyclophosphamide treatment, which selectively depletes suppressor T lymphocytes, did not enhance the delayed-type hypersensitivity response to SRBC in SHR. This may rule out the possibility of the involvement of the suppressor mechanism in the T cell depression of the SHR.

Correlation of HLA types in premature coronary artery disease: an attempt to define independent genetic risk factors

This study was designed to investigate whether isolated genetic factors, controlled by genes in the HLA chromosomal region, could be indicted as independent contributing influences in the genesis of premature coronary artery disease (CAD). Nineteen patients with fixed obstructive CAD documented by coronary angiography had no coronary risk factors with respect to age; levels of serum cholesterol, fasting triglycerides, and blood glucose; blood pressure; obesity; history of diabetes mellitus or hypertension; and cigarette-smoking history. Sixteen patients had a family history of CAD. HLA typing was restricted to antigens of the A and B loci. Control subjects (n = 1,157) were normal. At the A locus, no antigens demonstrated an observed frequency significantly higher than that expected from the control population. At the B locus, BW 38 had a statistically significant greater frequency (p less than 0.01) in the study group with CAD (21 percent) than in the control population (4 percent). The association between BW 38 and premature CAD lost its statistical significance when conservatively corrected for the number of HLA antigens tested by the Bonferroni adjustment. The relative risk for CAD if a patient had antigen BW 38 was 6.2. Our data suggest a statistically significant trend between the presence of HLA BW 38 and premature CAD. Whether the HLA tissue antigens are involved directly in the pathogenesis of CAD, act as markers for immune response genes, or serve as markers of other yet undefined genetic factors needs further study.