Herpes simplex virus type 2 infection is a risk factor for hypertension

Tropical diseases and risk of hypertension in the Amazon Basin: a cross-sectional study

Although infectious diseases have been associated with cardiovascular conditions, little is known about tropical disease burden and hypertension. We hypothesized that a history of tropical infections was associated with hypertension. We examined participants from outpatient clinics in the Amazon Basin who were interviewed about prior exposure to tropical diseases, including dengue, malaria hospitalization, and leishmaniasis. Hypertension was defined as a prior physician diagnosis of hypertension, treatment with anti-hypertensive medication, or a systolic blood pressure ≥140 mmHg and/or a diastolic blood pressure ≥90 mmHg. We used logistic regression models to examine the relationship between tropical infectious disease and hypertension. We included 556 participants (mean age 41 ± 15 years, 61% women) of whom 214 (38%) had hypertension and 354 (64%) had a history of tropical infectious disease. The distribution of tropical diseases was: dengue 270 (76%), malaria hospitalization 104 (29%) and leishmaniasis 48 (14%). Any prior tropical infection was significantly associated with prevalent hypertension (odds ratio 1.76 [95% CI 1.22-2.54], P = 0.003) and the association remained significant after adjusting for age, sex, body mass index, diabetes, hypercholesterolemia, socioeconomic status, smoking, vegetable intake and serum creatinine. Persons with a history of ≥2 tropical infections (n = 64) had the greatest risk of hypertension (odds ratio 2.04 [95% CI 1.15-3.63], P = 0.015). In adjusted models, prior infection with dengue was associated with hypertension (P = 0.006), but no associations were found with malaria hospitalization (P = 0.39) or leishmaniasis (P = 0.98). In conclusion, a history of tropical infectious disease was associated with hypertension. This finding supports the idea that pathogen burden may be related to cardiovascular conditions.

Association of hypertension with helicobacter pylori: A systematic review and meta‑analysis

Background and aims

The number of hypertensive population rises year by year recently, and their age becomes more youthful. For a long time, hypertension has long been regarded as a multi-factorial disease. In addition to smoking, genetics, diet and other factors, helicobacter pylori (H. pylori) had been regarded as a potential risk factor for hypertension in recent years. However, most studies had certain limitations and their results were inconsistent. Thus, it is necessary for us to assess the impact of H. pylori on hypertension through meta-analysis.

Methods

We searched all published relevant literature through multiple databases by July 23, 2021. Pooled results were calculated under the random effect model. Heterogeneity was evaluated by the Q statistic and the I² statistic. The risk of bias was evaluated via ROBINS-I tool. Publication bias was evaluated by the Egger test and Begg funnel plot.

Results

6 eligible studies involving 11317 hypertensive patients and 12765 controls were selected from 20767 retrieval records. Our research confirmed that H. pylori significantly increased the probability of suffering from hypertension in the random effect model (OR:1.34, 95% CI:1.10–1.63, P = 0.002, I² = 74%). The same results were also found in both Asian population and developing country (OR:1.28, 95%CI:1.05–1.55, P = 0.003, I² = 78.5%).

Conclusions

Our results confirmed that H. pylori was a vital risk factor for hypertension. H. pylori-infected people were 13.4% higher risk for hypertension than uninfected individuals. In addition, it will be a new method to prevent and treat hypertension by eradicating H. pylori.

Trial registration

The registration number for systematic review in PROSPERO CRD42021279677.

T-type calcium channels blockers inhibit HSV-2 infection at the late stage of genome replication

Herpes simplex virus type 2 (HSV-2) is a highly contagious sexually transmitted virus. The increasing emergence of drug-resistant viral strains has highlighted the crucial need for the development of new anti-HSV-2 drugs with different mechanisms. Ion channels that govern a wide range of cellular functions represent attractive targets for viral manipulation. Here, we tried to identify novel compounds to suppress HSV-2 infection in vitro by screening a small library with ion channels modulators. We found that several T-type calcium channel blockers including benidipine, lercanidipine, lomerizine and mibefradil inhibited HSV-2 infection, while L-type calcium channel blockers nifedipine and nitrendipine showed no significant effect on HSV-2 infection. Furthermore, we found that benidipine exerted the antiviral effect by suppressing the expression of viral genes in the late stage of viral infection. In conclusion, our study suggested that T-type calcium channel blockers, which are clinically wide used, could effectively inhibit HSV-2 infection. These findings could shed light on the mechanism and pharmacological study for HSV-2 infection in the future.

The Impact of Hypertension and Use of Calcium Channel Blockers on Tuberculosis Treatment Outcomes

BACKGROUND

Hypertension induces systemic inflammation, but its impact on the outcome of infectious diseases like tuberculosis (TB) is unknown. Calcium channel blockers (CCB) improve TB treatment outcomes in pre-clinical models, but their effect in patients with TB remain unclear.

METHODS

This retrospective cohort study, including all patients > 18 years receiving treatment for culture-confirmed, drug-sensitive TB from 2000 to 2016 at the National Taiwan University Hospital, assessed the association of hypertension and CCB use with all-cause and infection-related mortality during the first 9 months of TB treatment, as well as sputum-smear microscopy and sputum-culture positivity at 2 and 6 months.

RESULTS

1052 of the 2894 patients (36.4%) had hypertension. Multivariable analysis revealed that hypertension was associated with increased mortality due to all causes (HR 1.57, 95% confidence interval[CI], 1.23-1.99) and infections (HR 1.87, 95%CI, 1.34-2.6), but there was no statistical difference in microbiological outcomes when stratified based on hypertensive group. Dihydropyridine-CCB (DHP-CCB) use was associated with reduced all-cause mortality (HR 0.67, 95%CI: 0.45-0.98) only by univariate Cox regression. There was no association between DHP-CCB use and infection-related mortality (HR 0.78, 95%CI: 0.46-1.34) or microbiological outcomes in univariate or multivariate regression analyses.

CONCLUSIONS

Patients with hypertension have increased all-cause mortality and infection-related mortality during the 9 months following TB treatment initiation. DHP-CCB use may lower all-cause mortality in TB patients with hypertension. The presence of hypertension or the use of CCB did not result in a significant change in microbiological outcomes.

Viral infection and atherosclerosis

Several risk factors have been described for the pathogenesis of atherosclerosis. Infectious diseases are suggested to be a causative factor, and some viruses have been studied for their relation with atherosclerotic diseases. Studies report two hypotheses, direct and indirect effects, for the role of viral infections in atherogenesis. Viruses are able to initiate atherosclerosis by two different pathways. They can exert their direct effects on atherogenesis by infecting vascular cells and then inducing inflammation in the endothelium and smooth muscle cells. Alternatively, they can also apply indirect effects by infecting non-vascular cells and inducing systemic inflammation. In this review, we consider the available data about the effects and correlations of DNA and RNA viruses on atherosclerosis.

HSV infection is associated with gestational hypertension: results from the US National inpatient sample

The purpose of this study was to determine if there is an association between maternal herpes simplex virus (HSV) infection and pre-eclampsia/eclampsia or gestational hypertension. The US Nationwide Inpatient Sample database was searched for women aged 15–44 years who delivered in a hospital between 2005 and 2014. The patients were categorized into those with and without HSV and pre-eclampsia/eclampsia and gestational hypertension were compared between the groups. The analytic sample size (n=8 264 076) was equivalent to a population-based sample size of 40 653 030 patients. After adjusting for significant variables including age, race, income, insurance status, diabetes mellitus (DM), gestational DM, obesity, and multiple gestations, multivariate regression analysis indicated that HSV was associated with a higher OR for gestational hypertension (adjusted OR 1.038; 95% CI 1.004 to 1.072). However, HSV was not associated with pre-eclampsia/eclampsia (OR 1.001; 95% CI 0.968 to 1.035) in univariate regression analysis. The results of the current study suggest that HSV infection is associated with gestational hypertension but not pre-eclampsia. Given the prevalence of HSV infection and its potential association with hypertensive disorders of pregnancy, further study of HSV and hypertension in pregnancy is warranted.

Sympathetic-mediated activation versus suppression of the immune system: consequences for hypertension

It is generally well-accepted that the immune system is a significant contributor in the pathogenesis of hypertension. Specifically, activated and pro-inflammatory T-lymphocytes located primarily in the vasculature and kidneys appear to have a causal role in exacerbating elevated blood pressure. It has been proposed that increased sympathetic nerve activity and noradrenaline outflow associated with hypertension may be primary contributors to the initial activation of the immune system early in the disease progression. However, it has been repeatedly demonstrated in many different human and experimental diseases that sympathoexcitation is immunosuppressive in nature. Moreover, human hypertensive patients have demonstrated increased susceptibility to secondary immune insults like infections. Thus, it is plausible, and perhaps even likely, that in diseases like hypertension, specific immune cells are activated by increased noradrenaline, while others are in fact suppressed. We propose a model in which this differential regulation is based upon activation status of the immune cell as well as the resident organ. With this, the concept of global immunosuppression is obfuscated as a viable target for hypertension treatment, and we put forth the concept of focused organ-specific immunotherapy as an alternative option.

Influence of immune activation and inflammatory response on cardiovascular risk associated with the human immunodeficiency virus

Patients infected with the human immunodeficiency virus (HIV) have an increased cardiovascular risk. Although initially this increased risk was attributed to metabolic alterations associated with antiretroviral treatment, in recent years, the attention has been focused on the HIV disease itself. Inflammation, immune system activation, and endothelial dysfunction facilitated by HIV infection have been identified as key factors in the development and progression of atherosclerosis. In this review, we describe the epidemiology and pathogenesis of cardiovascular disease in patients with HIV infection and summarize the latest knowledge on the relationship between traditional and novel inflammatory, immune activation, and endothelial dysfunction biomarkers on the cardiovascular risk associated with HIV infection.

Unpacking the 'black box' of total pathogen burden: is number or type of pathogens most predictive of all-cause mortality in the United States?

A 'black box' paradigm has prevailed in which researchers have focused on the association between the total number of pathogens for which individuals are seropositive (i.e. total pathogen burden) and various chronic diseases, while largely ignoring the role that seropositivity for specific combinations of pathogens may play in the aetiology of such outcomes and consequently mortality. We examined the association between total pathogen burden as well as specific pathogen combinations and all-cause mortality in the United States. Data were from individuals aged ⩾25 years tested for cytomegalovirus (CMV), herpes simplex virus (HSV)-1, HSV-2 and Helicobacter pylori, with mortality follow-up to 31 December 2006 in the National Health and Nutrition Examination Survey (NHANES) III (N = 6522). We did not observe a statistically significant graded relationship between total pathogen burden level and all-cause mortality. Furthermore, compared to those seronegative for all four pathogens, the greatest statistically significant rate of all-cause mortality was for those CMV+/HSV-2+ (hazard ratio 1·95, 95% confidence interval 1·13-3·35) adjusting for age, gender, race/ethnicity, education level, body mass index (kg/m2) and smoking status. Interventions targeting prevention or treatment of particular pathogens may be more effective for reducing mortality than those focused solely on reducing overall pathogen burden.

Herpes simplex virus: prevalence in placental tissue and incidence in neonatal cord blood samples

Herpes simplex virus (HSV) infection is one of the most prevalent infectious diseases worldwide, with HSV-2 being primarily associated with genital infections. HSV-2 is believed to account for the majority of cases of neonatal herpes, which may cause diverse of complications in infected newborns. The present study sought to estimate the prevalence of HSV-2 in placental tissue samples and the incidence of HSV-2 in the umbilical cord blood of newborn infants. Placental tissue samples from 201 women (maternal-side and fetal-side = 402 specimens) and 184 neonatal cord blood samples, all collected at the obstetric ward of a University hospital were studied. HSV-2 was detected by means of nested PCR. The prevalence of HSV-2 in placental samples was 9.0% (n = 18), and the incidence of neonatal HSV-2 infection was 1.1% (n = 2). All HSV-2-positive patients were asymptomatic at the time of delivery and none reported genital herpes. Women with a time between rupture of membranes and delivery of ≥360 min had an approximately fourfold risk of HSV-2 infection in the placental tissue (95% CI 0.93-5.66, P = 0.01). These results suggest that HSV-2 is present in the placenta of asymptomatic women and that a risk of transmission to the neonate exists. New strategies must be implemented for the management of asymptomatic patients who are capable of transmitting the virus to the newborn.

Impact of viral and bacterial infections in coronary artery disease patients

Atherosclerosis is becoming an alarming disease for the existence of healthy human beings in the 21^st century. There are a growing number of agents, either modernized life style generated, competitive work culture related or infection with some bacterial or viral agents, documented every year. These infectious agents do not have proper diagnostics or detection availability in many poor and developing countries. Hence, as active medical researchers, we summarize some aspects of infectious agents and their related mechanisms in this review which may be beneficial for new beginners in this field and update awareness in the field of cardiovascular biology.

Association of pathogen burden and hypertension: the Persian Gulf Healthy Heart Study

BACKGROUND

Chronic infection with cytomegalovirus (CMV), Chlamydia pneumoniae, herpes simplex virus 1 (HSV-1), and Helicobacter pylori may contribute to essential hypertension. However, the evidence now available does not clarify whether the aggregate number of pathogens (pathogen burden) may be associated with hypertension.

METHODS

Sera from 1,754 men and women aged ≥25 years were analyzed for immunoglobulin G antibodies to C. pneumoniae, HSV-1, H. pylori, and CMV using enzyme-linked immunosorbent assay. The aggregate number of seropositives to the studied viral and bacterial agents was defined as pathogen burden. Hypertension was defined according to World Health Organization criteria.

RESULTS

A total of 459 (26.3%) of the subjects had hypertension. In the hypertensive group, 4.2% had 0 or 1 pathogens present, 20.6% had 2, 43.2% had 3, and 32.1% had 4; in the normotensive group, 7.9% had 0 or 1, 28.4% had 2, 42.7% had 3, and 21.0% had 4. Of the 4 studied pathogens, H. pylori seropositivity showed a significant independent association with hypertension (odds ratio (OR) =1.37; 95% confidence interval (CI) =1.05-1.79; P = 0.02). In multiple logistic regression analyses, the pathogen burden did not show a significant independent association with hypertension. Coinfection with H. pylori and C. pneumoniae was significantly associated with hypertension compared with double seronegativity after adjustment for age, sex, chronic low-grade inflammation, and cardiovascular risk factors (OR = 1.68; 95% CI = 1.14-2.47; P = 0.008].

CONCLUSIONS

The pathogen burden was not associated with hypertension. However, coinfection with C. pneumoniae and H. pylori showed a significant association with essential hypertension, independent of cardiovascular risk factors and chronic low-grade inflammation.

Seropositivity to herpes simplex virus type 2, but not type 1 is associated with premature cardiovascular diseases: a population-based cross-sectional study

OBJECTIVE

Thirty-five years after herpesviruses were suggested to induce atherosclerosis sero-epidemiological evidence on Herpes Simplex Viruses (HSV) remains sparse and controversial. We aimed to investigate the relationship between HSV-1 and HSV-2 infections and cardiovascular diseases (CVD).

METHODS AND RESULTS

A population-based cross-sectional study was conducted among 14,415 participants (mean age 34.3 years, range 20-49) of the National Health and Nutrition Examination Survey 1999-2010. Serum IgG-antibodies to HSV were measured by enzymatic immunodot assay and CVD were self-reported. CVD prevalence was 1.8%; 51.3% of participants were infected with HSV-1, 7.5% with HSV-2, and 15.2% with both. After adjusting for demographics, socioeconomic status, comorbidities, STD, and CVD risk factors, seropositivity to HSV-2 was positively associated with CVD (Odds ratio [OR] 1.56, 95% confidence interval [CI]: 1.09-2.21, P = 0.014), but not with HSV-1 (OR 1.13, 95% CI: 0.79-1.62).

CONCLUSION

HSV-2 may be associated with premature CVD, but not HSV-1.

Herpes simplex virus type 2 (HSV-2) as a coronary atherosclerosis risk factor in HIV-infected men: multicenter AIDS cohort study

We assessed associations of herpes simplex virus types 1 and 2 (HSV-1 and -2), cytomegalovirus (CMV), and human herpesvirus 8 (HHV-8) infection with subclinical coronary atherosclerosis in 291 HIV-infected men in the Multicenter AIDS Cohort Study. Coronary artery calcium (CAC) was measured by non-contrast coronary CT imaging. Markers for herpesviruses infection were measured in frozen specimens collected 10-12 years prior to case identification. Multivariable logistic regression models and ordinal logistic regression models were performed. HSV-2 seropositivity was associated with coronary atherosclerosis (adjusted odds ratio [AOR]=4.12, 95% confidence interval [CI]=1.58-10.85) after adjustment for age, race/ethnicity, cardiovascular risk factors, and HIV infection related factors. Infection with a greater number of herpesviruses was associated with elevated CAC levels (AOR=1.58, 95% CI=1.06-2.36). Our findings suggest HSV-2 may be a risk factor for subclinical coronary atherosclerosis in HIV-infected men. Infection with multiple herpesviruses may contribute to the increased burden of atherosclerosis.

Pathogens and atherosclerosis: update on the potential contribution of multiple infectious organisms to the pathogenesis of atherosclerosis

It is currently unclear what causes the chronic inflammation within atherosclerotic plaques. One emerging paradigm suggests that infection with bacteria and/or viruses can contribute to the pathogenesis of atherosclerosis either via direct infection of vascular cells or via the indirect effects of cytokines or acute phase proteins induced by infection at non-vascular sites. This paradigm has been supported by multiple epidemiological studies that have established positive associations between the risk of cardiovascular disease morbidity and mortality and markers of infection. It has also been supported by experimental studies showing an acceleration of the development of atherosclerosis following infection of hyperlipidaemic animal models. There are now a large number of different infectious agents that have been linked with an increased risk of cardiovascular disease. These include: Chlamydia pneumoniae, Porphyromonas gingivalis, Helicobacter pylori , influenza A virus, hepatitis C virus, cytomegalovirus, and human immunodeficiency virus. However, there are significant differences in the strength of the data supporting their association with cardiovascular disease pathogenesis. In some cases, the infectious agents are found within the plaques and viable organisms can be isolated suggesting a direct effect. In other cases, the association is entirely based on biomarkers. In the following review, we evaluate the strength of the data for individual or groups of pathogens with regard to atherosclerosis pathogenesis and their potential contribution by direct or indirect mechanisms and discuss whether the established associations are supportive of the infectious disease paradigm. We also discuss the failure of antibiotic trials and the question of persistent infection.

Association between human metapneumovirus seroprevalence and hypertension in elderly subjects in a long-term care facility

Recently, relations between hypertension and infections caused by several pathogens have been reported. However, few studies have examined the relationship between human metapneumovirus (hMPV) and hypertension in elderly inpatients. To assess the association between anti-hMPV-immunoglobulin G (IgG) titer and the prevalence of hypertension, we conducted a case-control study in a Japanese long-term care facility (LTCF). The participants included 84 hypertensive patients aged 65 years, and 84 age- and sex-matched normotensive controls (38 males and 46 females in each group; cases, 79.9±8.4 (s.d.) years; controls, 80.1±8.3 years). Data on underling chronic clinical conditions were collected. Titers were measured using an immunofluorescence assay kit. The significance of risk factor differences was analyzed using univariate and multivariate comparisons of cases and controls. All serum samples were positive for hMPV, and IgG titers ranged from 40-fold to more than 5120-fold. There were no significant sex- or age-related differences in log(2) (anti-hMPV-IgG titer/10) among the subjects. Compared with normotensive subjects, hypertensive patients presented significantly higher log(2) (anti-hMPV-IgG titer/10) values (P<0.001). After adjustment with multiple logistic analysis, the odds ratio for log(2) (anti-hMPV-IgG titer/10) was 1.42 (95% confidence interval 1.16-1.75, P=0.001) relative to normotensive subjects. In all subjects, stepwise multiple regression analysis revealed that both hypertension and a poor nutritional state independently contributed to increased log(2) (anti-hMPV-IgG titer/10). These observations suggest that an increased anti-hMPV-IgG titer was closely related to hypertension in elderly subjects in a Japanese LTCF.

Fetal exposure to herpesviruses may be associated with pregnancy-induced hypertensive disorders and preterm birth in a Caucasian population

OBJECTIVE

To investigate the role of fetal viral infection in the development of a range of adverse pregnancy outcomes (APOs), including pregnancy-induced hypertensive disorders (PIHD), antepartum haemorrhage (APH), birthweight <10th percentile (small for gestational age, SGA) and preterm birth (PTB).

DESIGN

Population-based case-control study.

SETTING

Laboratory-based study.

POPULATION

The newborn screening cards of 717 adverse pregnancy cases and 609 controls.

METHODS

Newborn screening cards were tested for RNA from enteroviruses and DNA from herpesviruses using polymerase chain reaction (PCR). The herpesviruses were detected using two PCRs, one detecting nucleic acids from herpes simplex virus (HSV)-1, HSV-2, Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus (HHV)-8, hereafter designated Herpes PCR group A viruses, and the other detecting nucleic acids from varicella-zoster virus (VZV), HHV-6 and HHV-7, hereafter designated Herpes PCR group B viruses.

MAIN OUTCOME MEASURE

Odds ratios and 95% CIs for specific APOs.

RESULTS

For both term and PTBs, the risk of developing PIHD was increased in the presence of DNA from Herpes PCR group B viruses (OR 3.57, 95% CI 1.10-11.70), CMV (OR 3.89, 95% CI 1.67-9.06), any herpesvirus (OR 5.70, 95% CI 1.85-17.57) and any virus (OR 5.17, 95% CI 1.68-15.94). The presence of CMV was associated with PTB (OR 1.61, 95% CI 1.14-2.27). No significant association was observed between SGA or APH and exposure to viral infection.

CONCLUSIONS

Fetal exposure to herpesvirus infection was associated with PIHD for both term and PTBs in this exploratory study. Exposure to CMV may also be associated with PTB. These findings need confirmation in future studies.

Pathogen burden in essential hypertension

BACKGROUND

Associations between pathogens and hypertension (HT) has been reported, but few studies have focused on the relationship between aggregate pathogens and HT. The present study explored whether the risk of HT is associated with each pathogen (defined as Chlamydia pneumoniae (C. pneumoniaee), mycoplasma pneumoniae (m. pneumoniae), helicobacter pylori (h. pylori) and coxsackie virus) or with aggregate pathogens in chinese mongolians.

METHODS AND RESULTS

One thousand and thirty Chinese Mongolians aged 30 years or more were recruited, including 488 hypertensive and 942 normotensive subjects. Enzyme-linked immunosorbent assay was used to detect IgG antibodies for C. pneumoniaee, M. pneumoniae, H. pylori and Coxsackie virus. The seroprevalence of Coxsackie virus was significantly associated with HT (odds ratio (OR) 3.7 after adjustment for risk factors), but no significant association was found for C. pneumoniae, M. pneumoniae and H. pylori (OR 1.32, 0.75 and 1.19, respectively). The results also showed that the risk of HT was associated with the aggregate pathogens: it increased with the increasing number of pathogens, and the ORs were 1.629, 2.653, 2.129, and 5.146 for 1, 2, 3 and 4 pathogens, respectively, after controlling for risk factors.

CONCLUSION

The risk of HT is associated with Coxsackie virus and aggregate pathogen load. The mechanism(s) underlying the associations remain to be elucidated further.

Extended exposure of lipopolysaccharide fraction from Porphyromonas gingivalis facilitates mononuclear cell adhesion to vascular endothelium via Toll-like receptor-2 dependent mechanism

Certain infectious pathogens contribute to atherogenesis. Indeed, the strong relationship between periodontal pathogens, such as Porphyromonas gingivalis (P.g.) and coronary heart disease has been demonstrated. We investigated the potential role of P.g. in monocyte-endothelial interaction. Lipopolysaccharide (LPS) fraction was extracted from P.g. cultured under anaerobic conditions and compared to that obtained from an Escherichia coli (E. coli) strain (JM109). Human umbilical vein endothelial cells (HUVECs) were incubated in the presence of P.g.-LPS fraction or E. coli-LPS fraction for various periods and mononuclear cell adhesion assays were conducted under flow. The adhesion of mononuclear cells to HUVECs treated with P.g.-LPS fraction peaked after 24h of incubation, whereas those treated with E. coli-LPS fraction maximized after 4h of incubation. A fluorescent immunobinding assay revealed that P.g.-LPS fraction significantly upregulated ICAM-1 and VCAM-1 in HUVECs. Antibodies against ICAM-1 and Toll-like receptor (TLR)-2, but not TLR-4, attenuated P.g.-LPS fraction-facilitated mononuclear cell adhesion to HUVECs. In conclusion, these results suggest that chronic P.g. infection may facilitate monocyte recruitment to vascular endothelium through sustained upregulation of ICAM-1 and VCAM-1. Our findings provide new evidence that the TLR-2 pathway may contribute to atherogenesis by mediating P.g.-LPS signal transduction.

Burden of infection and fat mass in healthy middle-aged men

OBJECTIVE

Our aim was to study the effect of exposure to four infections on fat mass.

RESEARCH METHODS AND PROCEDURES

This was a cross-sectional study of healthy middle-aged men from the general population (n = 74). Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)-1, HSV-2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme-linked immunosorbent assays (ELISAs). A total pathogen burden score based on these seropositivities [Quantitative Seropositivity Index (QSI)] was constructed. Fat mass was measured by bioelectrical impedance.

RESULTS

We observed significant relationships between the HSV-1 titer and fat mass and percentage fat mass. The associations were stronger when considering the infection burden. The QSI was significantly associated with fat mass (r = 0.30, p = 0.009) and percentage fat mass (r = 0.27, p = 0.01). Those subjects in the highest tertile of fat mass showed significantly higher QSI (259.5 +/- 74.1 vs. 206.9 +/- 78.2, p = 0.007). In subjects that were seropositive for Enteroviruses, the relationship between the QSI and fat mass was strengthened (r = 0.51, p = 0.02). In a multivariate regression analysis, the QSI, independently of age and C-reactive protein, contributed to 9% of fat mass variance.

DISCUSSION

Pathogen burden showed an association with fat mass. Subjects with increased fat mass could be more susceptible to developing multiple infections resulting in a chronic low-grade inflammation. We can not exclude the possibility that exposure to multiple infections leads to increased fat mass.

Burden of infection and insulin resistance in healthy middle-aged men

OBJECTIVE

We hypothesized that burden of infection could be associated with chronic low-grade inflammation, resulting in insulin resistance. We aimed to study the effect of exposure to four infections on insulin sensitivity in apparently healthy middle-aged men (n = 124).

RESEARCH DESIGN AND METHODS

By inclusion criteria, all subjects were hepatitis C virus antibody seronegative. Each study subject's serum was tested for specific IgG class antibodies against herpes simplex virus (HSV)-1, HSV-2, enteroviruses, and Chlamydia pneumoniae through the use of quantitative in vitro enzyme-linked immunosorbent assays. Insulin sensitivity was evaluated using minimal model analysis.

RESULTS

The HSV-2 titer was negatively associated with insulin sensitivity even after controlling for BMI, age, and C-reactive protein (CRP). The associations were stronger when considering the infection burden. In particular, in those subjects who were seropositive for C. pneumoniae, the relationship between the quantitative seropositivity index (a measure of the exposure to various pathogens) and insulin sensitivity was strengthened (r = -0.50, P < 0.0001). We also observed decreasing mean insulin sensitivity index with increasing seropositivity score in subjects positive for enteroviruses. In the latter, the relationship between insulin sensitivity and seropositivity was especially significant (r = -0.71, P < 0.0001). In a multivariate regression analysis, both BMI and quantitative seropositivity index (7%) independently predicted insulin sensitivity variance in subjects with C. pneumoniae seropositivity. When controlling for CRP, this association was no longer significant.

CONCLUSIONS

Pathogen burden showed the strongest association with insulin resistance, especially with enteroviruses and C. pneumoniae seropositivity. We hypothesize that exposure to multiple pathogens could cause a chronic low-grade inflammation, resulting in insulin resistance.