Sleep, inflammation and cardiovascular disease

Sex-specific association of sleep duration with subclinical indicators of metabolic diseases among asymptomatic adults

Background

Accumulating evidence suggests sleep duration may be involved in metabolic regulation. However, studies regarding the association with the early stage of the metabolic disease are limited, and the findings were inconsistent.

Methods

A study among 4922 asymptomatic adults was conducted based on a Chinese national survey in 2009. The early stage of metabolic diseases was evaluated using three proxies: triglyceride to high-density lipoprotein cholesterol ratio (TG/HDL-C), the product of triglyceride and fasting glucose (TyG), and lipid accumulation product (LAP). Multivariable linear and logistic regression models were used to explore the associations of sleep duration with the three indicators.

Results

The linear regression models revealed that, among females, sleep duration <7 h per day, compared with 7-9 h, was associated with an increased value of LAP and TyG by 25.232% (95%CI: 10.738%, 41.623%) and 0.104 (95%CI: 0.024, 0.185), respectively, in the crude model. The effects were attenuated but remained significant for LAP (11.405%; 95%CI: 1.613%, 22.262%). Similarly, the logistic regression models further found that sleep duration <7 h per day could increase the risk of elevated LAP (OR: 1.725, 95CI%:1.042, 2.856) after adjusting for multiple covariates. By contrast, no associations were found among males.

Conclusions

Short sleep duration was associated with subclinical indicators of metabolic diseases, and females were more susceptible to the association.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01626-w.

The Role of IL-6 and ET-1 in the Diagnosis of Coronary MicroVascular Disease in Women

BACKGROUND

Microvascular angina is a common clinical entity, with about a three-fold higher frequency in women. The pathogenesis of microvascular angina has not been much studied, but inflammation and endothelial dysfunction have been incriminated as the main mechanisms of this disease. Methoss: Our purpose was to analyze whether certain inflammatory markers, i.e., interleukin 6 (IL-6) and endothelin 1 (ET-1), can play a role in the diagnosis of microvascular angina in women.

RESULTS

Ninety women with ischemic heart disease were divided into two groups, based on their affliction with either microvascular or macrovascular disease. In general, the levels of IL6 and ET1 were similar between the two groups. Analyzing these marker levels according to the number of coronary lesions, we obtained an increased IL6 value that was similar for patients with microvascular angina, one-vessel, and two-vessel coronary disease, but significantly lower than in women with three-vessel coronary lesions. Also, in microvascular angina, IL6 level was correlated with the NYHA IV functional class. Unexpectedly, the level of ET1 was correlated with left ventricular systolic dysfunction.

CONCLUSIONS

In women with an increased suspicion of microvascular angina, in whom microvascular dysfunction cannot be tested invasively, IL-6 level, unlike the ET-1 level, might be considered a diagnostic marker of this disease.

Analysis of sleep characteristics and clinical outcomes of 139 adult patients with infective endocarditis after surgery

BACKGROUND

Little is known about the postoperative sleep quality of infective endocarditis patients during hospitalization and after discharge.

AIM

To investigate the sleep characteristics of infective endocarditis patients and to identify potential risk factors for disturbed sleep quality after surgery.

METHODS

The Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale were used to assess patient sleep quality. Logistic regression was used to explore the potential risk factors.

RESULTS

The study population (n = 139) had an average age of 43.40 ± 14.56 years, and 67.6% were men (n = 94). Disturbed sleep quality was observed in 86 patients (61.9%) during hospitalization and remained in 46 patients (33.1%) at 6 mo after surgery. However, both PSQI and Epworth Sleepiness Scale scores showed significant improvements at 6 mo (P < 0.001 and P = 0.001, respectively). Multivariable logistic regression analysis showed that the potential risk factors were age (odds ratio = 1.125, 95% confidence interval: 1.068-1.186) and PSQI assessed during hospitalization (odds ratio = 1.759, 95% confidence interval: 1.436-2.155). The same analysis in patients with PSQI ≥ 8 during hospitalization suggested that not using sleep medication (odds ratio = 15.893, 95% confidence interval: 2.385-105.889) may be another risk factor.

CONCLUSION

The incidence of disturbed sleep after infective endocarditis surgery is high. However, the situation improves significantly over time. Age and early postoperative high PSQI score are risk factors for disturbed sleep quality at 6 mo after surgery.

Temporal Links Between Self-Reported Sleep and Antibody Responses to the Influenza Vaccine

BACKGROUND

Growing evidence suggests that sleep plays an important role in immunological memory, including antibody responses to vaccination. However, much of the prior research has been carried out in the laboratory limiting the generalizability of the findings. Furthermore, no study has sought to identify sensitive periods prior to or after vaccination where sleep may have a stronger influence on antibody responses.

METHODS

Eighty-three healthy young adults completed 13 days of sleep diaries and received the trivalent influenza vaccine on day 3 of the study. Measures of self-reported sleep duration, sleep efficiency, and subjective sleep quality were assessed on each day. Antibody levels to the influenza viral strains were quantified at baseline and 1 and 4 months following influenza vaccination.

RESULTS

Shorter sleep duration, averaged over the collection period, was associated with fewer antibodies to the A/New Caledonia viral strain 1 and 4 months later, independent of baseline antibodies, age, sex, and cohort year. Analyses focused on nightly sleep on the days preceding and after the vaccination revealed that shorter sleep duration on the two nights before the vaccination predicted fewer antibodies 1 and 4 months later. Measures of self-reported sleep efficiency and subjective quality were unrelated to antibody responses to the influenza vaccination.

CONCLUSION

These findings provide further support for an association between sleep duration and antibody responses to the influenza vaccine and suggest that perhaps sleep on nights prior to vaccination are critical. If replicated, these findings may support sleep as a target for enhancing vaccination efficacy.

Effects of sleep deprivation on endothelial function in adult humans: a systematic review

Sleep deprivation is highly prevalent and is associated with increased cardiovascular disease (CVD) morbidity and mortality. Age-related alterations in sleep and chronobiology may exaggerate CVD susceptibility in older individuals. The mechanisms responsible for the association between sleep deprivation and CVD are not fully understood, but endothelial dysfunction may play a central role. Our objective was to conduct a systematic literature review to evaluate the evidence on the effects of sleep deprivation on endothelial function (EF). This review adhered to the PRISMA guidelines and was pre-registered with PROSPERO (#CRD42020192485, 07/24/2020). We searched PubMed, Web of Science, Embase, and Cochrane Library for articles published through May 1, 2020. Eligibility criteria included publication in English and use of well-established EF methodologies in adult humans. Two investigators independently performed the literature search, study selection, data extraction, risk-of-bias assessment, and qualitative data synthesis. Out of 3571 articles identified, 24 articles were included in the systematic review. Main findings include the following: (1) shorter sleep duration is associated with lower macrovascular EF; (2) not sleeping 7-9 h/night is linked with impaired microvascular EF; (3) sleep restriction impairs micro- and macrovascular EF; (4) acute total sleep deprivation impairs micro- and macrovascular EF but data on macrovascular EF are less consistent; and (5) shift work impairs macrovascular EF. In conclusion, sleep deprivation impairs EF, which may explain the link between insufficient sleep and CVD. Future investigations should fully elucidate the underlying mechanisms and develop strategies to combat the adverse endothelial effects of sleep deprivation across the lifespan.

Endothelin-1 and LOX-1 as Markers of Endothelial Dysfunction in Obstructive Sleep Apnea Patients

INTRODUCTION

The search of biochemical markers of endothelial dysfunction: lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1)-involved in atherosclerotic plaques formation-and endothelin-1 (ET-1)-potent vasoconstrictor-might help in detecting obstructive sleep apnea (OSA) patients at high risk of cardiovascular diseases.

MATERIAL AND METHODS

In 71 OSA patients (apnoea/hypopnoea index, AHI 28.2 ± 17.9/hour) and in 21 healthy controls the serum levels of LOX-1 and ET-1 were measured.

RESULTS

There were increased levels of ET-1 (1.58 ± 0.65 vs. 1.09 ± 0.38 pg/mL; p < 0.001) but not of LOX-1 in OSA patients as compared with healthy controls. In the patients' group ET-1 levels negatively correlated with serum LDL levels. LOX-1 levels positively correlated with fasting glucose levels and were higher in the patients with than without diabetes. Neither ET-1 nor LOX-1 correlated with OSA severity. In mild OSA patients, there was a negative correlation between LOX-1 and mean arterial oxygen saturation during sleep. In severe OSA patients, there was a positive correlation between LOX-1 levels and uric acid.

CONCLUSION

There is endothelial dysfunction in OSA patients as indicated by increased serum levels of ET-1 and possibly endothelial dysfunction in diabetic OSA patients as indicated by increased serum levels of LOX-1 and its correlation with fasting glucose levels.

Broken sleep predicts hardened blood vessels

Why does poor-quality sleep lead to atherosclerosis? In a diverse sample of over 1,600 individuals, we describe a pathway wherein sleep fragmentation raises inflammatory-related white blood cell counts (neutrophils and monocytes), thereby increasing atherosclerosis severity, even when other common risk factors have been accounted for. Improving sleep quality may thus represent one preventive strategy for lowering inflammatory status and thus atherosclerosis risk, reinforcing public health policies focused on sleep health.

Why does poor quality sleep correlate with cardiovascular disease? A large population-based study suggests that fragmented sleep contributes to atherosclerosis in humans by increasing inflammatory-related activity of white blood cells.

Sleep, Health and Wellness at Work: A Scoping Review

Many occupational factors may interfere with sleep. Sleep disturbances can, in turn, endanger the health and safety of workers. This rapid review of the literature identifies the main factors that alter the quantity and quality of sleep, indicates the effects these alterations have on the wellbeing of workers and suggests some health promotion measures.

Association of sleep apnea and sleep duration with peripheral artery disease: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Numerous biological pathways linking sleep disturbances to atherosclerosis have been identified, such as insulin resistance, inflammation, hypertension, and endothelial dysfunction. Yet, the association of sleep apnea and sleep duration with peripheral artery disease (PAD) is not well characterized.

METHODS

We evaluated the cross-sectional association between objectively measured sleep and prevalent PAD in 1844 participants (mean age 68 years) who in 2010-2013 had in-home polysomnography, 7-day wrist actigraphy and ankle-brachial index (ABI) measurements. We also evaluated the relation between self-reported diagnosed sleep apnea and PAD incidence in 5365 participants followed from 2000 to 2012. PAD was defined as ABI < 0.90.

RESULTS

In cross-sectional analyses, severe sleep apnea [apnea-hypopnea index (AHI) ≥30 vs. AHI <5] was associated with greater prevalent PAD only among black participants [multivariate adjusted prevalence ratio (95% CI): 2.29 (1.07-4.89); p-interaction = 0.05]. Short and long sleep duration was also associated with a 2-fold higher prevalence of PAD as compared with those who slept 7 h/night, in the full sample. In longitudinal analyses, participants with self-reported diagnosed sleep apnea were at higher risk of incident PAD [multivariable adjusted hazard ratio (95% CI): 1.93 (1.05-3.53)], with no evidence of interaction by race/ethnicity.

CONCLUSIONS

These findings support a significant association between sleep apnea and prevalent and incident PAD, with evidence for stronger associations with objectively measured sleep apnea and cross sectional PAD in blacks. In addition, short and long sleep duration was associated with PAD. These results identify sleep disturbances as a potential risk factor for PAD.

Behaviorally Assessed Sleep and Susceptibility to the Common Cold

STUDY OBJECTIVES

Short sleep duration and poor sleep continuity have been implicated in the susceptibility to infectious illness. However, prior research has relied on subjective measures of sleep, which are subject to recall bias. The aim of this study was to determine whether sleep, measured behaviorally using wrist actigraphy, predicted cold incidence following experimental viral exposure.

DESIGN, MEASUREMENTS, AND RESULTS

A total of 164 healthy men and women (age range, 18 to 55 y) volunteered for this study. Wrist actigraphy and sleep diaries assessed sleep duration and sleep continuity over 7 consecutive days. Participants were then quarantined and administered nasal drops containing the rhinovirus, and monitored over 5 days for the development of a clinical cold (defined by infection in the presence of objective signs of illness). Logistic regression analysis revealed that actigraphy- assessed shorter sleep duration was associated with an increased likelihood of development of a clinical cold. Specifically, those sleeping < 5 h (odds ratio [OR] = 4.50, 95% confidence interval [CI], 1.08-18.69) or sleeping between 5 to 6 h (OR = 4.24, 95% CI, 1.08-16.71) were at greater risk of developing the cold compared to those sleeping > 7 h per night; those sleeping 6.01 to 7 h were at no greater risk (OR = 1.66; 95% CI 0.40-6.95). This association was independent of prechallenge antibody levels, demographics, season of the year, body mass index, psychological variables, and health practices. Sleep fragmentation was unrelated to cold susceptibility. Other sleep variables obtained using diary and actigraphy were not strong predictors of cold susceptibility.

CONCLUSIONS

Shorter sleep duration, measured behaviorally using actigraphy prior to viral exposure, was associated with increased susceptibility to the common cold.

Tired telomeres: Poor global sleep quality, perceived stress, and telomere length in immune cell subsets in obese men and women

Poor sleep quality and short sleep duration are associated with increased incidence and progression of a number of chronic health conditions observed at greater frequency among the obese and those experiencing high levels of stress. Accelerated cellular aging, as indexed by telomere attrition in immune cells, is a plausible pathway linking sleep and disease risk. Prior studies linking sleep and telomere length are mixed. One factor may be reliance on leukocytes, which are composed of varied immune cell types, as the sole measure of telomere length. To better clarify these associations, we investigated the relationships of global sleep quality, measured by the Pittsburgh Sleep Quality Index (PSQI), and diary-reported sleep duration with telomere length in different immune cell subsets, including granulocytes, peripheral blood mononuclear cells (PBMCs), CD8+ and CD4+ T lymphocytes, and B lymphocytes in a sample of 87 obese men and women (BMI mean=35.4, SD=3.6; 81.6% women; 62.8% Caucasian). Multiple linear regression analyses were performed adjusting for age, gender, race, education, BMI, sleep apnea risk, and perceived stress. Poorer PSQI global sleep quality was associated with statistically significantly shorter telomere length in lymphocytes but not granulocytes and in particular CD8+ T cells (b=-56.8 base pairs per one point increase in PSQI, SE=20.4, p=0.007) and CD4+ T cells (b=-37.2, SE=15.9, p=0.022). Among separate aspects of global sleep quality, low perceived sleep quality and decrements in daytime function were most related to shorter telomeres. In addition, perceived stress moderated the sleep-CD8+ telomere association. Poorer global sleep quality predicted shorter telomere length in CD8+ T cells among those with high perceived stress but not in low stress participants. These findings provide preliminary evidence that poorer global sleep quality is related to telomere length in several immune cell types, which may serve as a pathway linking sleep and disease risk in obese individuals.

Association of Markers of Inflammation with Sleep and Physical Activity Among People Living with HIV or AIDS

This study examined associations of sleep and minutes spent in moderate-vigorous physical activity (MVPA) with C-reactive protein (CRP) and interleukin (IL)-6 among persons living with HIV. Cross-sectional analyses (n = 45) focused on associations of inflammatory outcomes (i.e., CRP and IL-6) with actigraph-derived sleep duration, latency, and efficiency; sleep onset; wake time; and wake-after-sleep-onset; as well as MVPA. Least square means for CRP and IL-6 by levels of sleep and MVPA were computed from general linear models. Individuals below the median of sleep duration, above the median for sleep onset, and below the median of MVPA minutes had higher CRP or IL-6 levels. Generally, individuals with both low MVPA and poor sleep characteristics had higher inflammation levels than those with more MVPA and worse sleep. Understanding the combined impact of multiple lifestyle/behavioral factors on inflammation could inform intervention strategies to reduce inflammation and therefore, chronic disease risk.

Sleep duration, insomnia, and markers of systemic inflammation: results from the Netherlands Study of Depression and Anxiety (NESDA)

Systemic inflammation has emerged as a potential pathway linking depressive and anxiety disorders with disease risk. Short and long sleep duration, as well as insomnia, are common among psychiatric populations and have previously been related to increased inflammation. The aim of the present study was to investigate associations between sleep duration and insomnia with biomarkers of inflammation and to explore whether these associations varied by psychiatric diagnostic status. To this end, self-reported measures of sleep duration, insomnia symptoms, and markers of inflammation, including C-reactive protein (CRP), interleukin-(IL)-6, and tumor necrosis factor (TNF)-α, were obtained in 2553 adults (aged 18-65 years) diagnosed with current/recent or remitted depressive and/or anxiety disorders and healthy controls enrolled in the Netherlands Study of Depression and Anxiety (NESDA). Regression analyses revealed associations between sleep duration and levels of CRP and IL-6 with higher levels observed in long sleepers. These associations remained statistically significant after controlling for age, gender, education, body mass index, smoking, alcohol consumption, medical comorbidities, medication use, psychotropic medication use, and psychiatric diagnostic status. There were no clear associations between insomnia symptoms and levels of inflammation. Relationships between sleep duration and inflammation did not vary as a function of psychiatric diagnostic status. These findings suggest that elevated levels of systemic inflammation may represent a mechanism linking long sleep duration and disease risk among those with and without depressive and anxiety disorders.

Yoga and psychophysiological determinants of cardiovascular health: comparing yoga practitioners, runners, and sedentary individuals

BACKGROUND

The evidence of cardiovascular benefits of yoga is promising, but lacks demonstrations of specificity compared to other interventions.

PURPOSE

The present cross-sectional study examined cardiovascular health markers in long-term practitioners of yoga (yogis), runners, and sedentary individuals.

METHODS

We compared physiological, psychological, and lifestyle variables associated with cardiovascular health across groups.

RESULTS

Yogis (n = 47) and runners (n = 46) showed favorable profiles compared to sedentary individuals (n = 52) on heart rate, heart rate variability, depression, perceived stress, and cigarette smoking. Runners and male yogis showed superior aerobic fitness compared to the sedentary group. Runners reported greater social support compared to other groups. Yogis demonstrated a lower respiration rate compared to sedentary individuals and were more likely to refrain from eating meat compared to other groups.

CONCLUSIONS

Yogis and runners demonstrated several cardiovascular health advantages over sedentary individuals. Our findings raise the possibility that yoga may improve aerobic fitness in men but not women.

Sleep duration during the school week is associated with C-reactive protein risk groups in healthy adolescents

BACKGROUND

The prevalence of short sleep duration in adolescence and the relevance of early risk factors to cardiovascular disease in adulthood suggest that adolescence is an opportune time to evaluate links between sleep duration and cardiovascular disease risk. We examined associations among actigraphy-assessed sleep duration and sleep debt with elevated C-reactive protein (CRP), a known risk factor for cardiovascular disease.

METHODS

Participants were 244 (56% Black, 48% male) healthy high school students, each of whom wore wrist actigraphs for one week and provided a fasting blood draw. CRP was examined as both a continuous and categorical outcome, with CRP >3 mg/L identifying a High Risk Group.

RESULTS

Sleep duration and sleep debt were significantly associated with CRP High Risk Group in covariate-adjusted analyses. Shorter sleep duration on school nights was associated with a greater likelihood of being in the High Risk CRP Group. Likelihood of being in the High Risk CRP Group was doubled in students who obtained an average of two or more hours of "catch up" sleep on weekend nights.

CONCLUSIONS

Reduced weekday sleep duration and sleep debt were both associated with CRP Risk Group in adolescence. That these relationships may be observed prior to the onset of clinical disease suggests that adolescence may provide an opportune period for disease prevention.

Addressing sleep disturbances: an opportunity to prevent cardiometabolic disease?

There is increasing awareness of the role of sleep disturbance as an important factor in health and disease. Although sub-clinical sleep disturbances (insufficient sleep duration or inadequate sleep quality) may be difficult to assess with conceptual and/or methodological clarity, this review attempts to summarize and synthesize these findings. First, the concept of sleep disturbance in a public health context is introduced, to provide context and rationale. Second, operational definitions of 'cardiometabolic disease' and 'sleep disturbance' are offered, to address many unclear operationalizations. Third, the extant literature is summarized regarding short or long sleep duration and/or insufficient sleep, insomnia and insomnia symptoms, general (non-specific sleep disturbances), circadian rhythm abnormalities that result in sleep disturbances, and, briefly, sleep-disordered breathing. Fourth, the review highlights the social/behavioural context of sleep, including discussions of sleep and race/ethnicity, socio-economic position, and other social/environmental factors, in order to place these findings in a social-environmental context relevant to public health. Fifth, the review highlights the issue of sleep as a domain of health behaviour and addresses issues regarding development of healthy sleep interventions. Finally, a research agenda of future directions is proposed.

Poor sleep quality potentiates stress-induced cytokine reactivity in postmenopausal women with high visceral abdominal adiposity

Sleep disturbance is a key behavioral risk factor for chronic medical conditions observed at high rates among overweight and obese individuals. Systemic inflammation, including that induced by stress, may serve as a common biological mechanism linking sleep, adiposity, and disease risk. To investigate these relationships, 48 postmenopausal women (mean age=61.8) completed a standardized laboratory stress task during which time blood was collected at baseline and 30, 50 and 90+ min after stressor onset to assess circulating levels of interleukin (IL)-6, IL-10, and IL-6/IL-10 ratio. Self-reported global sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) while adiposity was estimated by body mass index. Sagittal diameter was obtained in clinic to estimate visceral abdominal adiposity. Multi-level growth curve models revealed that poorer self-reported sleep quality was associated with greater stress-induced increases in IL-6/IL-10 ratio. In terms of adiposity, higher sagittal diameter, but not BMI, was associated with greater IL-6 reactivity (p's<0.05). Further, associations between sleep quality and cytokine reactivity varied as a function of sagittal diameter. Among poor sleepers (1 SD above mean of PSQI score), stress-induced increases in IL-6 and IL-6/IL-10 ratio were significantly steeper in those with high visceral adiposity (1 SD above the mean of sagittal diameter) compared to those with low visceral adiposity (1 SD below the mean of sagittal diameter). In sum, poorer sleep quality and greater visceral adiposity, separately and especially in combination, are associated with greater stress-related increases in systemic inflammation. This research may help elucidate the complex link between sleep, obesity and inflammatory disease risk.

Associations between change in sleep duration and inflammation: findings on C-reactive protein and interleukin 6 in the Whitehall II Study

Cross-sectional evidence suggests associations between sleep duration and levels of the inflammatory markers, C-reactive protein and interleukin-6. This longitudinal study uses data from the London-based Whitehall II study to examine whether changes in sleep duration are associated with average levels of inflammation from 2 measures 5 years apart. Sleep duration (≤5, 6, 7, 8, ≥9 hours on an average week night) was assessed in 5,003 middle-aged women and men in 1991/1994 and 1997/1999. Fasting levels of C-reactive protein and interleukin-6 were measured in 1997/1999 and 2002/2004. Cross-sectional analyses indicated that shorter sleep is associated with higher levels of inflammatory markers. Longitudinal analyses showed that each hour per night decrease in sleep duration between 1991/1994 and 1997/1999 was associated with higher levels of C-reactive protein (8.1%) and interleukin-6 (4.5%) averaged across measures in 1997/1999 and 2002/2004. Adjustment for longstanding illness and major cardiometabolic risk factors indicated that disease processes may partially underlie these associations. An increase in sleep duration was not associated with average levels of inflammatory markers. These results suggest that both short sleep and reductions in sleep are associated with average levels of inflammation over a 5-year period.

Sleep duration, cardiovascular disease, and proinflammatory biomarkers

Habitual sleep duration has been associated with cardiometabolic disease, via several mechanistic pathways, but few have been thoroughly explored. One hypothesis is that short and/or long sleep duration is associated with a proinflammatory state, which could increase risk for cardiovascular and metabolic diseases. This hypothesis has been largely explored in the context of experimental sleep deprivation studies which have attempted to demonstrate changes in proinflammatory markers following acute sleep loss in the laboratory. Despite the controlled environment available in these studies, samples tend to lack generalization to the population at large and acute sleep deprivation may not be a perfect analog for short sleep. To address these limitations, population based studies have explored associations between proinflammatory markers and habitual sleep duration. This review summarizes what is known from experimental and cross-sectional studies about the association between sleep duration, cardiovascular disease, and proinflammatory biomarkers. First, the association between sleep duration with both morbidity and mortality, with a focus on cardiovascular disease, is reviewed. Then, a brief review of the potential role of proinflammatory markers in cardiovascular disease is presented. The majority of this review details specific findings related to specific molecules, including tumor necrosis factor-α, interleukins-1, -6, and -17, C-reactive protein, coagulation molecules, cellular adhesion molecules, and visfatin. Finally, a discussion of the limitations of current studies and future directions is provided.