Johanna Helmersson

Association of Type 2 Diabetes With Cyclooxygenase-Mediated Inflammation and Oxidative Stress in an Elderly Population

Background—Involvement of cyclooxygenase (COX)-mediated inflammation in type 2 diabetes has not been studied, and the association between cytokine-mediated inflammation and diabetes is not fully clarified. Methods and Results—15-Keto-dihydro-prostaglandin F2&agr; (a metabolite of prostaglandin F2&agr; and an indicator of COX-mediated inflammation), high-sensitivity C-reactive protein (CRP), serum amyloid protein A (SAA), 8-iso-PGF2&agr; (a nonenzymatic, free radical product of arachidonic acid and an indicator of oxidative stress), and &agr;-tocopherol were measured in a population-based sample of 77-year-old men (n=765), in which 112 men had type 2 diabetes. The inflammatory indicators were increased in men with diabetes (urinary 15-keto-dihydro-PGF2&agr;, P <0.001, CRP and SAA, P <0.05). However, when adjusted for body mass index, waist circumference, or fasting insulin, no association was found between diabetes and CRP or SAA. The oxidative stress indicator 8-iso-PGF2&agr; in urine was increased (P <0.01) in men with diabetes. Patients who were newly diagnosed with diabetes (<7 years since diagnosis) had increased urinary 15-keto-dihydro-PGF2&agr; and decreased &agr;-tocopherol, but 8-iso-PGF2&agr; was unaltered. Conclusions—This is the first study to show that type 2 diabetes in elderly men is related to COX-mediated inflammation, reflected by enhanced prostaglandin formation. The high levels of cytokine-mediated acute-phase proteins observed in men with diabetes appear to be related to obesity and increased fasting insulin. The results further suggest that the appearance of chronic inflammation is an early process in the pathogenesis of diabetes, whereas oxidative injury may be a later process, possibly related to inflammation.

Low dietary intake of β-carotene, α-tocopherol and ascorbic acid is associated with increased inflammatory and oxidative stress status in a Swedish cohort

Fruit and vegetable consumption has been associated with a reduced risk of several diseases including CVD. A part of these effects seen could be linked to anti-inflammatory and antioxidative effects, although this has not been thoroughly investigated. The present study was designed to investigate the effects of the dietary intake of beta-carotene, alpha-tocopherol and ascorbic acid on in vivo biomarkers of inflammation (PGF2alpha, high-sensitive C-reactive protein (hsCRP) and IL-6 formation) and oxidative stress (F2-isoprostane formation), the two important factors associated with accelerated atherosclerosis. The dietary intake of 704 participants in the Uppsala Longitudinal Study of Adult Men (ULSAM) at age 70 years was registered and inflammatory and oxidative stress biomarkers were quantified 7 years later. The registered dietary intakes of ascorbic acid and alpha-tocopherol were negatively associated linearly and in quartiles with both PGF2alpha, hsCRP, IL-6 and F2-isoprostanes, where ascorbic acid intake generally was more strongly associated. Dietary intake of beta-carotene was only significantly negatively associated with F2-isoprostanes. In conclusion, the present study is the first to suggest that the intake of food rich in antioxidants is associated with reduced cyclo-oxygenase- and cytokine-mediated inflammation and oxidative stress at 7 years of follow-up. These associations could be linked to the beneficial effects of fruit and vegetables observed on CVD.

Systemic Inflammation and the Risk of Alzheimer's Disease and Dementia: A Prospective Population-Based Study

Inflammation is suggested to be involved in the pathogenesis of Alzheimers disease (AD). Serum interleukin-6 (IL-6) and high sensitivity serum reactive protein C (hsCRP) as markers of systemic inflammation were analyzed at two examinations of the ULSAM-study, a longitudinal, community-based study of elderly men (age 70, n = 1062 and age 77, n = 749). In addition, serum amyloid protein A (SAA) and urinary prostaglandin F2alpha (PGF2alpha) metabolite levels were analyzed at age 77 in this cohort. Two serial samples (at ages 70 and 77) were available from 704 individuals. Using Cox regression analyses, associations between serum IL-6, hsCRP, SAA and PGF2alpha metabolite levels and risk of AD, any type of dementia (all-cause dementia) and non-AD dementia were analyzed. On follow-up (median, 11.3 years) in the age 70 cohort, 81 subjects developed AD and 165 subjects developed all-cause dementia. Serum IL-6, hsCRP, SAA, or PGF2alpha levels were not associated with risk of AD. At age 70, high IL-6 levels were associated with an increased risk of non-AD dementia (Hazard ratio 2.21 for above vs. below/at median, 95%confidence interval 1.23-3.95, p-value = 0.008). A longitudinal change in CRP or IL-6 levels was not associated with AD ordementia. In conclusion, Serum IL-6, hsCRP, SAA, and PGF2alpha levels are not associated with the risk of AD. High serum IL-6 levels may be associated with increased risk of non-AD dementia.

Oxidative stress and bone mineral density in elderly men: antioxidant activity of alpha-tocopherol.

Oxidative stress has recently been identified as a pivotal pathogenetic factor of bone loss in mice, but its importance in humans is not clear. We aimed to investigate the association between urinary 8-iso-PGF(2 alpha) levels, a major F(2)-isoprostane and a reliable in vivo biomarker of oxidative stress, and bone mineral density (BMD), and to study whether vitamin E in the form of serum alpha-tocopherol, a scavenger of peroxyl radicals, modifies the association. In 405 men, urinary 8-iso-PGF(2 alpha) and serum alpha-tocopherol were measured at age 77 years and BMD at age 82 years. One SD increase in 8-iso-PGF(2 alpha) corresponded to an approximately 2-4% decrease in average adjusted BMD values of total body, lumbar spine, and proximal femur (all P<0.001). Serum alpha-tocopherol levels seemed to modify the association between urinary 8-iso-PGF(2 alpha) and BMD. Men with alpha-tocopherol levels below the median combined with high oxidative stress, i.e., 8-iso-PGF(2 alpha) above the median, had 7% (95% CI 3-11%) lower BMD at the lumbar spine and 5% (95% CI 2-9%) lower BMD at the proximal femur. In elderly men high oxidative stress is associated with reduced BMD, which is more pronounced in individuals with low serum levels of the antioxidant vitamin E.

Regulatory factors of basal F2-isoprostane formation: Population, age, gender and smoking habits in humans

Oxidative stress is assumed to be the key underlying factor in the pathogenesis of many common diseases. This study describes the basal levels of 8-iso-PGF2α, a major F2-isoprostane and an in vivo oxidative stress biomarker in healthy subjects from three countries, namely Italy, Poland and Sweden, in relation to their smoking habits, age and gender. It studied urinary 8-iso-PGF2α in 588 subjects from Sweden (n=220), Italy (n=203) and Poland (n=165). Polish subjects had the highest levels of F2-isoprostanes followed by the Swedish and Italians when adjusted for smoking, age, sex and creatinine and the inter-country differences were statistically significant. Smokers had significantly higher levels of 8-iso-PGF2α compared to non-smokers in all countries and there was a moderate decrease with age. Women had only slightly lower 8-iso-PGF2α than men. There is a difference in F2-isoprostane levels in vivo between countries. Smoking, age and gender affect isoprostane formation and should be taken into consideration in clinical studies of oxidative stress.

Serum selenium predicts levels of F2-isoprostanes and prostaglandin F2alpha in a 27 year follow-up study of Swedish men.

Low concentrations of selenium (Se) predict mortality and cardiovascular diseases in some populations. The effect of Se on in vivo indicators of oxidative stress and inflammation, two important features of atherosclerosis, in human populations is largely unexplored. This study investigated the longitudinal association between serum selenium (s–Se) and a golden standard indicator of oxidative stress in vivo (8-iso-prostaglandin F2α, a major F2-isoprostane), an indicator of cyclooxygenase (COX)-mediated inflammation (prostaglandin F2α), high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6) and serum amyloid A protein (SAA) in a follow-up study of 27 years. The s–Se was measured in 615 Swedish men at 50 years of age in a health investigation. The status of oxidative stress and inflammation was evaluated in a re-investigation 27 years later by quantification of urinary 8-iso-PGF2α and 15-keto-dihydro- PGF2α (a major metabolite of PGF2α) and serum hsCRP, SAA and IL-6. Men in the highest quartile of s–Se at age 50 had decreased levels of 8-iso-PGF2α compared to all lower quartiles and decreased levels of PGF2α compared to all lower quartiles at follow-up. These associations were independent of BMI, diabetes, hyperlipidemia, hypertension, smoking, α-tocopherol and β-carotene at baseline. The s–Se was not associated with hsCRP, SAA or IL-6 at follow-up. In conclusion, high concentrations of s–Se predict reduced levels of oxidative stress and subclinical COX-mediated (but not cytokine-mediated) inflammation in a male population. The associations between Se, oxidative stress and inflammation, respectively, might be related to the proposed cardiovascular protective property of Se.

Serum Cathepsin S Is Associated with Serum C-Reactive Protein and Interleukin-6 Independently of Obesity in Elderly Men

OBJECTIVE Cathepsin S has been suggested provide a mechanistic link between obesity and atherosclerosis, possibly mediated via adipose tissue-derived inflammation. Previous data have shown an association between circulating cathepsin S and inflammatory markers in the obese, but to date, community-based reports are lacking. Accordingly, we aimed to investigate the association between serum levels of cathepsin S and markers of cytokine-mediated inflammation in a community-based sample, with prespecified subgroup analyses in nonobese participants. METHODS Serum cathepsin S, C-reactive protein (CRP), and IL-6 were measured in a community-based cohort of elderly men (Uppsala Longitudinal Study of Adult Men; mean age 71 years, n = 991). CRP and IL-6 were also measured at a reexamination after 7 yr. RESULTS After adjustment for age, body mass index, fasting plasma glucose, diabetes treatment, systolic blood pressure, diastolic blood pressure, hypertension treatment, serum cholesterol, serum high-density lipoprotein cholesterol, prior cardiovascular disease, smoking, and leisure time physical activity, higher cathepsin S was associated with higher CRP (regression coefficient for 1 sd increase, 0.13; 95% confidence interval 0.07-0.19; P < 0.001) and higher serum IL-6 (regression coefficient for 1 sd increase, 0.08; 95% confidence interval 0.01-0.14; P = 0.02). These associations remained similar in normal-weight participants (body mass index <25 kg/m(2), n = 375). In longitudinal analyses, higher cathepsin S at baseline was associated with higher serum CRP and IL-6 after 7 yr. CONCLUSIONS These results provide additional evidence for the interplay between cathepsin S and inflammatory activity and suggest that this association is present also in normal-weight individuals in the community.

Systemic tocopherols and F2-isoprostanes and the risk of Alzheimer's disease and dementia: a prospective population-based study

Oxidative stress in the brain is suggested to be involved in the pathophysiology of Alzheimers disease (AD). In this study, serum alpha- and gamma-tocopherol, the two major systemic antioxidants, were analyzed at two examinations of the ULSAM-study, a longitudinal, community-based study of elderly men (age 70, n = 616 and age 77, n = 761). In addition, urinary F2-isoprostane levels, as markers of systemic oxidative stress, were analyzed at the age of 77 in this cohort (n = 679). Cox regression analyses were used to examine associations between serum alpha-, gamma-tocopherol and urinary F2-isoprostane levels and AD, any type of dementia (all-cause dementia) and non-AD dementia. On follow-up (median, 12.3 years), 40 subjects developed AD and 86 subjects developed all-cause dementia. Serum alpha- and gamma-tocopherol or urinary F2-isoprostane levels were not associated with the future risk of AD or dementia. In conclusion, systemic serum alpha- and gamma-tocopherol and urinary F2-isoprostane levels are not associated with the future risk of AD or dementia and do not seem to be useful predictors of clinical AD or dementia.

A polymorphism in the cyclooxygenase 1 gene is associated with decreased inflammatory prostaglandin F2α formation and lower risk of cardiovascular disease

This study investigates the impact of genetic variation in the cyclooxygenase-1 (COX-1) gene on formation of the vasoconstrictive, pro-inflammatory prostaglandin F(2)(alpha) (PGF(2)(alpha)) and development of cardiovascular disease (CVD). We determined COX-1 genotypes, PGF(2)(alpha) formation and CVD prevalence in a Swedish cohort of 809 men at age 77 years. Of these, 237 had a history of CVD according to the registry data. Four of nine COX-1 single nucleotide polymorphisms were associated with altered formation of PGF(2)(alpha) (P<0.05). Two COX-1 gene variants (rs10306135 and rs883484) remained significantly associated with altered PGF(2)(alpha) formation after adjusted significance level for multiple testing (alpha-level=0.0059). Furthermore, individuals homozygote for the variant allele rs10306135 had lower prevalence of CVD, compared to the common allele (0% versus 30%, P=0.0047). In conclusion, subjects homozygote for the variant allele of a COX-1 gene polymorphism represent a subpopulation of men with decreased PGF(2)(alpha) formation and lower prevalence of CVD.

Postsurgical inflammatory response is not associated with increased serum cystatin C values

OBJECTIVES Cystatin C is used both as a glomerular filtration (GFR) marker and a cardiovascular risk marker. There are several studies showing an association between cystatin C and inflammatory markers and it has been suggested that the inflammatory response in itself could result in elevated cystatin C levels. The aim of this study was to evaluate if an induced inflammatory response has an effect on cystatin C levels in humans. MATERIALS AND METHODS CRP and cystatin C were analyzed in serum samples from orthopedic surgery patients (n=29). The patients were sampled prior to surgery and four and thirty days after surgery. RESULTS The surgery induced a pronounced CRP elevation on day four, median 137.3 (interquartile range 104.1-178.2) mg/L compared to 1.94 (1.20-8.70) mg/L before surgery, P<0.001, but no significant difference in cystatin C levels before and four and thirty days after surgery could be seen. CONCLUSIONS The orthopedic surgery-induced inflammatory response does not cause changes in cystatin C levels.