Is hormone replacement therapy protective for venous ulcer of the lower limbs?

Differences in risk profile associated with varicose veins and chronic venous insufficiency - results from the Bonn Vein Study 1

Background: The aim of this publication is to demonstrate similarities and differences in the association of risk factors with the prevalence of different manifestations of chronic venous disease (CVD), like varicose veins (VV), venous oedema (C3) and severe chronic venous insufficiency (CVI) in the population-based cross-sectional Bonn Vein Study 1 (BVS). Patients and methods: In the BVS 1 between 13.11.2000 and 15.3.2002, 3.072 participants, 1350 men and 1722 women, from a simple random sample of the general population of the city of Bonn and two rural townships aged 18-79 years were included. The overall response proportion was 59%. All participants answered a standardized questionnaire including information about socio-economic data, lifestyle, physical activity, medical history, and quality of life. Venous investigations were performed clinically and by a standardized duplex examination by trained investigators. The CEAP classification in the version of 1996 was used to classify the findings. Logistic regression models were performed for the association of possible risk factors with VV, venous edema (C3) and severe CVI (C4-C6). The predictive risk (PR) describes the association of the diseases and the possible influencing factors. Results: VV, venous oedema (C3) and severe CVI (C4-C6) have common risk factors like higher age, number of pregnancies, family history of VV and overweight or obesity. Female gender is significantly associated with VV and C3 but not with severe CVI (C4-C6). High blood pressure and urban living are only associated with C3 and C4-C6 disease whereas prolonged sitting is associated with C3 and lower social class with C4-C6 exclusively. Discussion: In many epidemiological studies risk factors were associated with chronic venous disorders in general. Our data show that VV, venous edema and severe CVI may have different risk profiles. Venous edema is more often associated with arterial hypertension and sedentary lifestyle whereas lower social class seems to be a risk factor for severe CVI including venous ulcers. Conclusions: The differences in the association of risk factors to VV, venous edema and severe CVI should be considered if prevention and treatment of chronic venous diseases are planned. As examples, compression stockings could be proposed in sitting profession to prevent oedema, VV patients with risk factors like obesity might benefit from early treatment for VV and obesity. More longitudinal evaluation of risk factors is necessary to evaluate the true risk profile of CVD.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

Quantifying Age-Related Changes in Skin Wound Metabolism Using In Vivo Multiphoton Microscopy

Objective: The elderly are at high risk for developing chronic skin wounds, but the effects of intrinsic aging on skin healing are difficult to isolate due to common comorbidities like diabetes. Our objective is to use multiphoton microscopy (MPM) to find endogenous, noninvasive biomarkers to differentiate changes in skin wound healing metabolism between young and aged mice in vivo. Approach: We utilized MPM to monitor skin metabolism at the edge of full-thickness, excisional wounds in 24- and 4-month-old mice of both sexes for 10 days. MPM can assess quantitative biomarkers of cellular metabolism in vivo by utilizing autofluorescence from the cofactors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD). Results: An optical redox ratio of FAD/(NADH+FAD) autofluorescence and NADH fluorescence lifetime imaging revealed dynamic changes in keratinocyte function during healing. Aged female mice demonstrated an attenuation of keratinocyte proliferation during wound healing detectable optically through a higher redox ratio and longer NADH fluorescence lifetime. By measuring the correlation between NADH lifetime and the optical redox ratio at each day, we also demonstrate sensitivity to the proliferative phase of wound healing. Innovation: Label-free MPM was used to longitudinally monitor individual wounds in vivo, which revealed age-dependent differences in wound metabolism. Conclusion: These results indicate in vivo MPM can provide quantitative biomarkers of age-related delays in healing, which can be used in the future to provide patient-specific wound care.

Protocol for a longitudinal cohort study: determination of risk factors for the development of first venous leg ulcer in people with chronic venous insufficiency, the VEINS (venous insufficiency in South Florida) cohort

INTRODUCTION

Chronic venous insufficiency (CVI) affects up to one-third of the adult population yet venous leg ulcers (VLU), a significant complication of CVI, only affect 1%-2% of adults in the USA. Why some develop VLU and others do not is unclear. VLU have a significant impact on quality of life and are extremely costly and difficult to treat. Moreover, VLU prevalence is increasing, doubling in the last 20 years. In order to characterise the differences between people with CVI and those who ultimately develop VLU, we aim to set up the unique venous insufficiency in South Florida cohort.

METHODS AND ANALYSIS

Subjects will be recruited from the University of Miami Hospital and Clinic's vascular laboratory database, which began in July 2011. Any adult age 18-95 who has had venous reflux detected on duplex ultrasound of the lower extremities is included. Approximately 2500 patients are already in the database that meet these criteria, with an estimated 2500 additional potential subjects to be recruited from the vascular laboratory database over the next 5 years. Subjects with a history of VLU prior to the duplex study date will be excluded. Data will be collected via review of the Doppler study report, patient phone interview and review of the electronic medical record. Subjects will be contacted for follow-up every 3 months for at least 5 years until the study endpoint, development of first VLU (fVLU), is reached. In order to estimate the time from reflux documentation to fVLU, Kaplan-Meier survival curves will be constructed. Cox proportional hazard regression models will be constructed to investigate possible risk factors.

ETHICS AND DISSEMINATION

This study is approved by the University of Miami's Institutional Review Board. We hope to present the results of this study to the scientific community at conferences and in peer-reviewed journals.

Estrogen receptor-mediated signalling in female mice is locally activated in response to wounding

Estrogen deprivation is associated with delayed healing, while Hormone Replacement Therapy (HRT) accelerates acute wound healing and protects against development of chronic wounds. Estrogen exerts its effects on healing via numerous cell types by signalling through the receptors ERα and ERβ, which bind to the Estrogen Responsive Element (ERE) and initiate gene transcription. The ERE-luciferase transgenic mouse model has been influential in assessing real-time in vivo estrogen receptor activation across a range of tissues and pathologies. Using this model we demonstrate novel temporally regulated peri-wound activation of estrogen signalling in female mice. Using histological methods we reveal that this signal is specifically localised to keratinocytes of the neoepidermis and wound margin dermal cells. Moreover using pharmacological agonists we reveal that ERβ induces ERE-mediated signal in both epidermal and dermal cells while ERα induces ERE-mediated signal in dermal cells alone. Collectively these novel data demonstrate rapid and regional activation of estrogen signalling in wounded skin. A more complete understanding of local hormonal signalling during repair is essential for the focussed development of new therapies for wound healing.

The role of estrogen deficiency in skin ageing and wound healing

The links between hormonal signalling and lifespan have been well documented in a range of model organisms. For example, in C. elegans or D. melanogaster, lifespan can be modulated by ablating germline cells, or manipulating reproductive history or pregnenolone signalling. In mammalian systems, however, hormonal contribution to longevity is less well understood. With increasing age human steroid hormone profiles change substantially, particularly following menopause in women. This article reviews recent links between steroid sex hormones and ageing, with special emphasis on the skin and wound repair. Estrogen, which substantially decreases with advancing age in both males and females, protects against multiple aspects of cellular ageing in rodent models, including oxidative damage, telomere shortening and cellular senescence. Estrogen's effects are particularly pronounced in the skin where cutaneous changes post-menopause are well documented, and can be partially reversed by classical Hormone Replacement Therapy (HRT). Our research shows that while chronological ageing has clear effects on skin wound healing, falling estrogen levels are the principle mediator of these effects. Thus, both HRT and topical estrogen replacement substantially accelerate healing in elderly humans, but are associated with unwanted deleterious effects, particularly cancer promotion. In fact, much current research effort is being invested in exploring the therapeutic potential of estrogen signalling manipulation to reverse age-associated pathology in peripheral tissues. In the case of the skin the differential targeting of estrogen receptors to promote healing in aged subjects is a real therapeutic possibility.

The phytoestrogen genistein promotes wound healing by multiple independent mechanisms

Genistein has been implicated in the beneficial effects of soy on human health, particularly in the context of ageing. In post-menopausal women reduced systemic estrogen leads to a range of age-associated pathologies, including delayed cutaneous wound healing. We have previously shown that this can be reversed by estrogen replacement. However, the effect of genistein on the skin is poorly understood and crucially the influence of genistein on wound healing has not been assessed. 10-week-old ovariectomised mice were systemically treated with 17beta-estradiol or genistein. Genistein substantially accelerated wound repair, associated with a dampened inflammatory response. Unexpectedly, co-treatment with the ER antagonist ICI had little impact on the anti-inflammatory, healing promoting effects of genistein. Thus genistein's actions are only partially mediated via classical estrogen receptor-dependent signalling pathways. Indeed, we report that alternative (cell-type specific) signalling mechanisms are activated in the skin in response to genistein treatment.

Delayed wound healing in elderly people

Our ability to heal wounds deteriorates with age, leading in many cases to a complete lack of repair and development of a chronic wound. Moreover, as the elderly population continues to grow the prevalence of non-healing chronic wounds is escalating. Cutaneous wound repair occurs through a combination of overlapping phases, including an initial inflammatory response, a proliferative phase and a final remodelling phase. In elderly subjects the inflammatory response is delayed, macrophage and fibroblast function compromised, angiogenesis reduced and re-epithelialization inhibited. Whilst a large body of historic research describes the defective processes that lead to delayed healing, only recently have the molecular mechanisms by which these defects arise begun to be elucidated. Current therapies available for treatment of chronic wounds in elderly people are surprisingly limited and generally ineffective. Thus there is an urgent need to develop new therapeutic strategies based on these recent molecular and cellular insights.

Selective estrogen receptor modulators accelerate cutaneous wound healing in ovariectomized female mice

A lack of systemic hormones in elderly postmenopausal women leads to delayed cutaneous wound healing. This effect can be reversed by systemic or topical estrogen replacement in both humans and rodent models. Over recent years selective estrogen receptor modulators have been developed in an attempt to achieve the beneficial effects of estrogen clinically, while minimizing the detrimental side effects. The effects of selective estrogen receptor modulators on the skin are poorly understood, and the effects on wound healing have not been assessed. In this study we treated 10-wk-old ovariectomized mice with estradiol, tamoxifen (TAM), raloxifene (RAL), or vehicle and examined the effect on healing of full-thickness incisional wounds. Both TAM and RAL substantially accelerate healing, associated with a dampened inflammatory response and altered inflammatory cytokine profile. In vitro TAM and RAL demonstrate antiinflammatory activity comparable to estrogen. These results have significant implications for the clinical modulation of wound healing.

Polymorphisms spanning the 0N exon and promoter of the estrogen receptor-beta (ERbeta) gene ESR2 are associated with venous ulceration

Venous ulcers are characterized by excessive inflammation and raised levels of proinflammatory cytokines. Estrogen has been shown to accelerate the rate of wound healing in elderly subjects by dampening the inflammatory response. The estrogen receptor (ER) proteins, ER-alpha (ERalpha) and ER-beta (ERbeta) mediate the actions of estrogen during wound repair through the activation or repression of target gene transcription. Recent evidence implicates the chromosomal region harboring the ERbeta gene with venous ulceration in a British Caucasian population, highlighting the need to conduct further genetic interrogation. To address this, we conducted a case-control study to investigate whether single nucleotide polymorphisms in the ERbeta gene are associated with venous ulceration in elderly (age >50 years) subjects. We recruited a case group (n = 124, 56 males and 68 females) consisting of patients with an active venous ulcer and a control group consisting of individuals from the general population with no evidence of venous disease or history of venous ulceration (n = 380, 189 males and 191 females). Polymorphisms in close proximity to upstream regulatory regions of the ERbeta gene, including the 0N exon and promoter transcribed in inflammatory cells, were significantly (p < 0.05) associated with venous ulceration. A major susceptibility haplotype carried by 23% (26/112) of cases compared with only 10% (27/276) of controls (odds ratio = 2.8, 95% confidence interval = 1.6-5.0) was significantly (p < 0.01) associated with elevated serum levels of tumor necrosis factor-alpha. In conclusion, common variation in the regulatory regions of the ERbeta gene may pre-dispose to venous ulceration in a British Caucasian population.

The hormonal regulation of cutaneous wound healing

Conditions of impaired wound healing in the elderly are associated with substantial morbidity and mortality and impose a significant financial burden upon the world's health services. The findings of a series of recent studies have served to highlight the contrasting contributions made by sex steroid hormones to the regulation of cutaneous repair processes. Although estrogens accelerate healing, the actions of the "male" sex hormones 5alpha-dihydrotestosterone and testosterone are primarily deleterious. The shift that occurs in the balance between serum estrogen and androgen levels as a normal feature of human aging may therefore have important consequences for fundamental tissue repair processes.

Estrogen status and skeletal muscle recovery from disuse atrophy

Although estrogen loss can alter skeletal muscle recovery from disuse, the specific components of muscle regrowth that are estrogen sensitive have not been described. The primary purpose of this study was to determine the components of skeletal muscle mass recovery that are biological targets of estrogen. Intact, ovariectomized (OVX), and ovariectomized with 17β-estradiol replacement (OVX+E2) female rats were subjected to hindlimb suspension for 10 days and then returned to normal cage ambulation for the duration of recovery. Soleus muscle mass returned to control levels by day 7 of recovery in the intact animals, whereas OVX soleus mass did not recover until day 14. Intact rats recovered soleus mean myofiber cross-sectional area (CSA) by day 14 of recovery, whereas the OVX soleus remained decreased (42%) at day 14. OVX mean fiber CSA did return to control levels by day 28 of recovery. The OVX+E2 treatment group recovered mean CSA at day 14, as in the intact animals. Myofibers demonstrating central nuclei were increased at day 14 in the OVX group, but not in intact or OVX+E2 animals. The percent noncontractile tissue was also increased 29% in OVX muscle at day 14, but not in either intact or OVX+E2 groups. In addition, collagen 1a mRNA was increased 45% in OVX muscle at day 14 of recovery. These results suggest that myofiber growth, myofiber regeneration, and extracellular matrix remodeling are estrogen-sensitive components of soleus muscle mass recovery from disuse atrophy.

The dinucleotide (CA) repeat polymorphism of estrogen receptor beta but not the dinucleotide (TA) repeat polymorphism of estrogen receptor alpha is associated with venous ulceration

Venous ulcers are the predominant form of chronic wound in the elderly, accounting for around 70% of all cases. The steroid sex hormone estrogen plays a crucial role in normal human skin maintenance and during cutaneous wound repair following injury. Estrogen can reverse age-related impaired wound healing by dampening the inflammatory response and increasing matrix deposition at the wound site. The molecular actions of estrogen are mediated through two nuclear sex steroid hormone receptors, estrogen receptor alpha (ERalpha) and beta (ERbeta). We have conducted a case-control study to investigate whether dinucleotide repeat polymorphisms in the estrogen receptor genes are associated with venous ulceration in the UK Caucasian population. Genomic fragments containing the ERalpha dinucleotide (TA)(n) repeat polymorphism or the ERbeta dinucleotide (CA)(n) repeat polymorphism were amplified by polymerase chain reaction in subject DNA samples and genotyped according to fragment length by capillary electrophoresis. There was no evidence to suggest that the TA repeat polymorphism of ERalpha was associated with venous ulceration. However, the CA*18 allele of the ERbeta CA repeat polymorphism was significantly associated with venous ulceration (n = 120, OR = 1.8, 95% CI = 1.1-2.8, P = 0.02). When the CA repeats alleles were grouped together into either low (L < or = 18) or high (H > 18) numbers of CA repeats, the low (L) repeat allele was significantly associated with venous ulceration (OR = 1.5, 95% CI = 1.0-2.2, P = 0.03). Our results show that a specific ERbeta variant is associated with impaired healing in the elderly, predisposing individuals to venous ulceration.

The Epidemiology of Chronic Venous Insufficiency and Varicose Veins

Chronic venous disease is a common condition presenting to physicians in Western Europe and the United States. This article provides a comprehensive review of the published literature in the English language, from 1942 to the present, and focuses on the prevalence of chronic venous insufficiency and varicose veins, as well as the involved risk factors. Prevalence estimates vary widely by geographic location, with the highest reported rates in Western countries. Reports of prevalence of chronic venous insufficiency vary from < 1% to 40% in females and from < 1% to 17% in males. Prevalence estimates for varicose veins are higher, <1% to 73% in females and 2% to 56% in males. The reported ranges in prevalence estimations presumably reflect differences in the population distribution of risk factors, accuracy in application of diagnostic criteria, and the quality and availability of medical diagnostic and treatment resources. Established risk factors include older age, female gender, pregnancy, family history of venous disease, obesity, and occupations associated with orthostasis. Yet, there are several factors that are not well documented, such as diet, physical activity and exogenous hormone use, which may be important in the development of chronic venous disease and its clinical manifestations.

Estradiol induces proliferation of keratinocytes via a receptor mediated mechanism

In this study, we investigated the effects of estradiol on the proliferation of neonatal keratinocytes, the expression of estrogen receptor isoforms, and the signaling mechanisms by which estradiol mediates cell growth. We demonstrate that estradiol binds neonatal keratinocytes with high affinity (Kd=5.2nM) and limited capacity (Bmax of 14.2fmol/mg of protein), confirming the presence of estrogen binding sites. Using specific antibodies, we demonstrate that keratinocytes express both estrogen receptor (ER)-alpha and ER-beta. At physiological concentrations, estradiol up-regulates the level of ER-alpha receptors in keratinocytes and induces keratinocyte proliferation. The proliferative effect of estradiol requires the availability of functional estrogen receptors, as it is abrogated by anti-estrogen administration. Estradiol effect on keratinocyte proliferation is most likely mediated in part by activation of a nongenomic, membrane-associated, signaling pathway involving activation of the extracellular signal regulated kinases 1 and 2 and in part by the genomic signaling pathway through activation of nuclear receptors.

Estrogen modulates cutaneous wound healing by downregulating macrophage migration inhibitory factor

Characteristic of both chronic wounds and acute wounds that fail to heal are excessive leukocytosis and reduced matrix deposition. Estrogen is a major regulator of wound repair that can reverse age-related impaired wound healing in human and animal models, characterized by a dampened inflammatory response and increased matrix deposited at the wound site. Macrophage migration inhibitory factor (MIF) is a candidate proinflammatory cytokine involved in the hormonal regulation of inflammation. We demonstrate that MIF is upregulated in a distinct spatial and temporal pattern during wound healing and its expression is markedly elevated in wounds of estrogen-deficient mice as compared with intact animals. Wound-healing studies in mice rendered null for the MIF gene have demonstrated that in the absence of MIF, the excessive inflammation and delayed-healing phenotype associated with reduced estrogen is reversed. Moreover, in vitro assays have shown a striking estrogen-mediated decrease in MIF production by activated murine macrophages, a process involving the estrogen receptor. We suggest that estrogen inhibits the local inflammatory response by downregulating MIF, suggesting a specific target for future therapeutic intervention in impaired wound-healing states.

Risk factors for the first-time development of venous ulcers of the lower limbs: the influence of heredity and physical activity

The objective of this prospective case-control study was to identify and quantify demographic and clinical risk factors for venous ulcer disease, with special emphasis on heredity and physical activity. Patients presenting to a participating vascular surgery department between January and December 1997 with a first open venous ulcer served as cases. Controls were sampled among patients with subacute conditions such as skin problems, back pain, cold, headache/migraine, sore throat, and mild ear infections and were matched on referral physician, age (+/-5 years), and gender. Subjects were eligible if they were 18 years or older and were excluded if they had nonpalpable pedal pulse or any chronic active diseases such as cancer or AIDS. Cases' and controls' statuses were ascertained by the participating physicians. Data on risk factors were collected with an interviewer-administered questionnaire and were self-reported by patients. The mean age of participants was 61 years for cases (n = 102) and 59 years for controls (n = 200). Family history of maternal venous insufficiency (odds ratio (OR) = 6.8, 95% confidence interval (CI) = [1.9, 24.3]95%), vigorous exercise (OR = 8.9, CI = [1.1, 72.0]95%), and history of deep vein thrombosis (DVT) (OR = 17.6, CI = [2.9, 106.8]95%) were found to be significant predictors of venous ulcers in matched multivariate logistic regression analysis; number of pregnancies was also a significant risk factor in women (OR = 1.2, Cl = [1.0, 1.5]95%). Our study suggests that knowledge of family history of venous insufficiency and monitoring of physical activity will lead to ulcer prevention. Although physical activity is recommended for patients with venous insufficiency, vigorous exercise increases the likelihood of ulcerations.