Linkage study of fibrinogen levels: the Strong Heart Family Study

Processed Meat, but Not Unprocessed Red Meat, Is Inversely Associated with Leukocyte Telomere Length in the Strong Heart Family Study

BACKGROUND

Telomeres are repetitive nucleotide sequences (TTAGGG) and their associated proteins at the end of eukaryote chromosomes. Telomere length shortens throughout the lifespan with each cell division, and leukocyte telomere length (LTL) is often used as a biomarker of cellular aging. LTL is related to many chronic diseases, including cardiovascular disease and diabetes. However, to our knowledge, the relation between LTL and risk factors for cardiovascular disease and diabetes, such as dietary intake of processed meat and unprocessed red meat, is largely unknown.

OBJECTIVE

We examined the associations of processed meat intake and unprocessed red meat intake with LTL.

METHODS

This cross-sectional study comprised 2846 American Indians from the Strong Heart Family Study who participated in the 2001-2003 examination. Dietary factors, including past-year consumption of processed meat and unprocessed red meat, were assessed with the use of a 119-item Block Food-Frequency Questionnaire. LTL was measured with the use of quantitative polymerase chain reaction. Generalized estimating equations were used to examine the associations of intake of processed meat and unprocessed red meat with LTL.

RESULTS

Consumption of processed meat was negatively associated with LTL after adjustment for age, sex, site, education, smoking, alcohol use, physical activity, and other dietary factors. For every additional daily serving of processed meat, LTL was 0.021 units (telomeric product-to-single-copy gene ratio) shorter (β ± SE = -0.021 ± 0.008, P = 0.009). No association was observed between the intake of unprocessed red meat and LTL (β ± SE = 0.008 ± 0.011, P = 0.46).

CONCLUSIONS

In the Strong Heart Family Study, consumption of processed meat, but not unprocessed red meat, was associated with shorter LTL, a potential mediator for several age-related diseases. Further studies are needed to better understand the biological mechanism by which processed meat intake influences cellular aging.

Plasma levels of thrombomodulin, plasminogen activator inhibitor-1 and fibrinogen in elderly, diabetic patients with depressive symptoms

Background

Diabetes, depression and aging have been associated with pro-inflammatory and prothrombotic state.

Aim

The aim of the study was to determine the plasma levels of thrombomodulin, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen in elderly diabetic patients with and without depressive symptoms and to examine factors (including thrombomodulin, PAI-1, fibrinogen levels) associated with depressive symptoms in elderly patients with type 2 diabetes (T2DM).

Methods

A total of 276 T2DM elders were evaluated: 82 subjects with depressive symptoms and 194 controls. Data were collected concerning biochemical parameters and biomarkers.

Results

Plasma thrombomodulin, PAI-1 and fibrinogen were elevated in patients with depressive symptoms compared to controls. Thrombomodulin level was correlated with fibrinogen and PAI-1 levels. All parameters were correlated with the Geriatric Depression Scale-30 score. The univariate logistic regression models revealed that variables which increased the likelihood of diagnosis of depressive symptoms in elderly patients with T2DM were: female sex, smoking habit, longer duration of T2DM, hyperlipidemia, neuropathy, increased number of co-morbidities, higher BMI, and higher levels of total and LDL cholesterol, thrombomodulin, PAI-1 and fibrinogen. In addition, the multivariable analysis indicated that female sex, smoking habit, increased number of co-morbidities, higher BMI, and higher levels of LDL cholesterol and thrombomodulin are the predisposing factors for depressive symptoms.

Conclusions

Elderly diabetic patients with depressive symptoms have higher levels of thrombomodulin, PAI-1 and fibrinogen. Further prospective larger studies are needed to provide potential directions for the research, treatment and prevention of co-morbid depression and diabetes.

American Indian/Alaska Native willingness to provide biological samples for research purposes

This article examines the willingness of American Indian/Alaska Natives (AI/AN) to provide biological samples for research purposes. Prior cases of abuse and misuse of individuals, materials, and data highlight ethical research concerns. Investigators may be hesitant to engage AI/ANs in research projects. We conducted a survey of AI/ANs in the central plains region of the US over 1 year. This convenience sample completed a series of questions on biological samples and research. Survey results (N=998) indicate that 70.15% of AI/ANs would be willing to provide saliva/spit for a specific study with the proper consent and control of samples. In conclusion, researchers should find ways to work with and for AI/ANs, assuring participant input in the research process.

Markers of inflammation, metabolic risk factors, and incident heart failure in American Indians: the Strong Heart Study

Inflammation may play a role in increased risk of heart failure (HF) that is associated with obesity, metabolic syndrome (MS), and diabetes. This study investigated associations between inflammatory markers, MS, and incident HF in a population with a high prevalence of diabetes, obesity, and MS. The cohort consisted of 3098 American Indians without prevalent cardiovascular disease who had C-reactive protein (CRP) and fibrinogen measured at the Strong Heart Study phase II examination. Independent associations between inflammatory markers, MS, and HF were analyzed by Cox hazard models. During a mean follow-up of 11 years, 218 participants developed HF. After the adjustment for cardiovascular risk factors, fibrinogen, (hazard ratio [HR], 1.36; 95% confidence interval [CI], 1.15-1.59) but not CRP (HR, 1.25; 95% CI, 0.97-1.32) remained a significant HF predictor. In individuals without diabetes, concomitant presence of MS and elevated CRP or fibrinogen increased HF risk (for MS and CRP: HR, 2.02; 95% CI, 0.95-4.31; for CRP and fibrinogen: HR, 1.75; 95% CI, 0.83-3.72). In a population with a high prevalence of obesity, MS, and diabetes, elevated CRP and fibrinogen increased HF risk. These associations are attenuated by the adjustments for conventional risk factors suggesting that inflammation acts in concert with metabolic and clinical risk factors in increasing HF risk.

Genetic regulation of inflammation-mediated activation of haemostasis: family-based approaches in population studies

Blood coagulation and inflammation play a key role in atherosclerosis and thrombosis. Candidate gene and genome wide association studies have identified potential specific genes that might have a causal role in these pathogenic processes. The analysis of quantitative traits is more powerful as they are closer to direct gene action than disease phenotypes. Thus linkage-based studies on extended families might be useful both to estimate the heritability and to map the genetic loci responsible for the regulation of the trait. Family-based studies may estimate high heritability for thrombosis and quantitative traits regarding both platelet aggregation and blood coagulation. Some specific loci relevant to thrombosis have been identified, with some of them showing a direct pleiotropic effect on the risk of thrombosis. Haemostasis factors can be activated by inflammatory stimuli. Fibrinogen level is genetically correlated with C-reactive protein levels with a link for both traits on chromosomes 12 and 21. Genes related to prostanoid biosynthesis, involved both in inflammation and thrombosis, show high heritability levels in both enzyme expression and prostanoid production. Considering that few large family-based linkage studies have as yet been performed on haemostasis and inflammation-related traits, additional studies are highly needed. We are performing a family-based linkage study on large pedigrees (750 subjects from 23 families with juvenile myocardial infarction and 31 control families), to identify genes responsible for quantitative traits involved in the pathway progressively going from inflammation to haemostasis, cell activation, thrombus formation and cardiovascular events.

Involvement of Depressive Catecholamines as Thrombosis Risk/Inflammatory Markers in Non-Smoker, Non-Obese Congestive Heart Failure, Linked to Increased Epidermal Growth Factor-Receptor (EGF-R) Production

The EGF-R, also known as HER-1 or erbB-1 (EGF-R/HER-1/erbB-1), is a member of the human epithelial receptor tyrosine kinase family. sEGF-R is considered to play a role in cardiac (patho)physiology. We aimed to investigate whether soluble EGF-R is increased in congestive heart failure (CHF) patients and if related to disease severity. Soluble EGF-R, vitamin D, parathyroid hormone (PTH) was studied, and being evaluated in relation to Ca(2+), lipids, hsCRP, fibrinogen, serotonin, norepinepherine (NE). The study compared non-smoker, non-obese male CHF patients (n = 50) with age and gender-matched essential hypertension (HTN) patients (n = 20). Moreover, comparison with healthy control volunteers (n = 20) were employed. EGF-R/HER-1/erbB-1 was higher (P = 0.013) in 50 CHF male patients mean 12 ± 0.7 fmol/ml, than in 20 HTN, 9.25 ± 0.6 fmol/ml or in 20 controls, 6.25 ± 1 fmol/ml. Serum EGF-R levels correlated positively with hsCRP and NE, and were highest among CVD patients (n = 70) as well as negatively with vitamin D and HDL-C. EGF-R/HER-1/erbB-1 levels are increased in HTN and more in CHF patients. This study confirms a strong association between catecholamines as well as EGF-R/HER-1/erbB-1 levels with PTH and low vitamin D levels, being related to hyperlipidemia and inflammation (hsCRP and fibrinogen) in CVD. Moreover, contributing to the complex process of the inflammatory component of atherosclerosis in hypertensive patients that leads eventually to CHF.

Expanded network of inflammatory markers of atherogenesis: where are we now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesis via activation of monocytes/macrophages and T lymphocytes. Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.

Expanded Network of Inflammatory Markers of Atherogenesis: Where Are We Now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesisviaactivation of monocytes/macrophages and T lymphocytes.Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.