Reciprocal association of C-reactive protein with adiponectin in blood stream and adipose tissue

Circulating inflammatory markers in polycystic ovary syndrome: a systematic review and metaanalysis

OBJECTIVE

To perform a review and metaanalysis of the studies evaluating the status of serum inflammatory markers in women with polycystic ovary syndrome (PCOS).

DESIGN

Systematic review and metaanalysis of articles published in English before January 2010 and identified using the PubMed search engine.

SETTING

Academic hospital.

PATIENT(S)

Women with PCOS and appropriate controls.

INTERVENTION(S)

Measurement of serum concentrations of inflammatory markers by high-sensitivity techniques.

MAIN OUTCOME MEASURE(S)

Metaanalyses of the mean difference in serum C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations among patients with PCOS and appropriate controls, applying random-effects models to limit interstudy variability, and using appropriate estimates of evidence dissemination bias.

RESULT(S)

Metaanalysis of the 31 articles meeting inclusion criteria showed that circulating CRP was 96% higher in women with PCOS compared to controls (95% confidence interval, 71%-122%; z = 7.32) without evidence of dissemination bias (Egger's regression intercept, 0.45; 95% confidence interval, -2.30 to 3.21). These findings persisted after excluding five studies with mismatches in body mass, frequency of obesity, or both, between women with PCOS and controls. Metaanalyses involving 10 studies of IL-6, and nine studies of TNF-α revealed no statistically significant differences between PCOS and controls.

CONCLUSION(S)

Women with PCOS exhibit an elevation in circulating CRP that is independent of obesity. This finding corroborates existing molecular evidence of the chronic low-grade inflammation that may underpin the pathogenesis of this disorder.

Adiponectin and hypertension

Adipose tissue secretes a variety of bioactive molecules, also known as adipocytokines or adipokines. Obesity, in particular, visceral fat accumulation, is implicated in the dysregulated secretion of adipocytokines, which can contribute to the development of metabolic syndrome and cardiovascular diseases. Adiponectin is an adipocytokine that is exclusively secreted from adipose tissue, but its plasma levels are reduced in obese subjects, especially those with visceral fat accumulation. Adiponectin has a variety of protective properties against obesity-linked complications, such as hypertension, metabolic dysfunction, atherosclerosis, and ischemic heart disease. Adiponectin exerts the beneficial effects on vascular disorders by directly affecting components of vascular tissue. This review will discuss clinical and experimental findings that examine the role of adiponectin in regulation of hypertension and vascular function.

Soy isoflavones, diet and physical exercise modify serum cytokines in healthy obese postmenopausal women

OBJECTIVES

Evaluate the effect of diet, physical exercise, and a daily oral intake of a soy isoflavones extract (Fisiogen(®)) contained 200 mg of Glycine max, which corresponded to 80 mg of isoflavone (60.8 mg of genistein, 16 mg of daidzein and 3.2 mg of glicitein) on leptin and other adipokines plasma levels in healthy obese postmenopausal women.

METHODS

A multicentric randomized longitudinal prospective cohort study was conducted in a sample of 87 healthy obese postmenopausal women. Patients were randomly assigned to a 1200 kcal diet and exercise group (control group) or a group of 1200 kcal diet, exercise, and daily oral intake of daily oral intake of a soy isoflavones extract (Fisiogen(®)) contained 200 mg of Glycine max, which corresponded to 80 mg of isoflavone (60.8 mg of genistein, 16 mg of daidzein and 3.2 mg of glicitein) (soy isoflavones group) along 6 months. Main outcome measures were: anthropometric measures, body composition, leptin, adiponectin, TNF-alpha, homocysteine, C-reactive protein, glucose, insulin, lipid profile and oestradiol serum levels, Kupperman index and Cervantes Scale.

RESULTS

Mean serum leptin and TNF-alpha levels declined after 6 months in both groups of the study, but only women in the soy isoflavones group showed a significant increase of mean serum levels of adiponectin.

CONCLUSIONS

Diet, physical exercise and daily oral intake of a soy isoflavones extract (Fisiogen(®)) contained 200 mg of Glycine max, which corresponded to 80 mg of isoflavone (60.8 mg of genistein, 16 mg of daidzein and 3.2 mg of glicitein) have a beneficial effect on serum leptin, adiponectin and TNF-α in healthy obese postmenopausal women after 6 months of treatment.

Adipokines in inflammation and metabolic disease

The worldwide epidemic of obesity has brought considerable attention to research aimed at understanding the biology of adipocytes (fat cells) and the events occurring in adipose tissue (fat) and in the bodies of obese individuals. Accumulating evidence indicates that obesity causes chronic low-grade inflammation and that this contributes to systemic metabolic dysfunction that is associated with obesity-linked disorders. Adipose tissue functions as a key endocrine organ by releasing multiple bioactive substances, known as adipose-derived secreted factors or adipokines, that have pro-inflammatory or anti-inflammatory activities. Dysregulated production or secretion of these adipokines owing to adipose tissue dysfunction can contribute to the pathogenesis of obesity-linked complications. In this Review, we focus on the role of adipokines in inflammatory responses and discuss their potential as regulators of metabolic function.

[Adipocytokines in rheumatoid arthritis and obesity]

In obese rheumatoid arthritis (RA) patients inflammatory mechanisms and cardiovascular secondary disorders are possibly related to changed expression of adipocytokines. Various adipocytokines and inflammatory parameters were examined in 112 patients (23.2% men; 76.8% women) suffering from RA: leptin, adiponectin, visfatin, sCD40 L, CRP, and ESR. Average BMI was 27.6 (+/-5.6). Leptin and BMI as well as visfatin and BMI correlated positively, BMI and adiponectin, however, showed a negative correlation. Significant differences between normal-weight and obese RA patients were found in both leptin and adiponectin measurements. Visfatin showed a positive correlation with CRP; sCD40 ligand which is a marker for increased T-cell activity correlated with CRP and ESR. Patients with low adiponectin levels (<10 microg/ml) more often suffered from cardiovascular diseases (28.6%) than those with enhanced adiponectin (14.3%). Increased pro-inflammatory leptin and decreased anti-inflammatory adiponectin in obese RA patients can be associated with RA activity and enhanced cardiovascular risk.

Association of adiponectin levels and insulin demand in critically ill patients

PURPOSE

Intensive care unit patients usually have a deregulated glucose homeostasis and present with hyperglycemia and hyperinsulinemia, suggesting overall insulin resistance. Adiponectin has significant anti-inflammatory and insulin-sensitizing effects and is diminished in morbidly obese and in critically ill patients. Reduced adiponectin could contribute to insulin resistance in these patients. We examined how far insulin demand in critically ill patients is correlated with patient adiponectin levels.

PATIENTS AND METHODS

Adiponectin, resistin, leptin, insulin demand, minimal and maximal blood sugar levels, epinephrine, and hydrocortisone demand were measured 1 day after diagnosis of severe sepsis or septic shock in 25 patients (8 female, 17 male; median age 65 years; range: 31 to 87 years).

RESULTS

INSULIN DEMAND (RANGE: 0-8 IU/h; median 3.5 IU) was positively correlated with serum adiponectin levels (median: 10.1 μg/mL; range: 2.9-47.6 μg/mL; r = +0.56, P < 0.01). There was no significant correlation between insulin demand and leptin serum levels (median: 18.1 ng/mL; range: 0.3-80.7 ng/mL; r = +0.29, P = 0.08) or resistin serum levels (median: 103.9 ng/mL; range: 14.7-352.3 ng/mL; r = +0.13, P = 0.27). Epinephrine demand (median: 0.08 μg/kg*min; range: 0.02-0.63 μg/kg*min) was negatively correlated with male adiponectin levels (r = -0.58; P < 0.01; females: r = -0.36; P = 0.19) and positively correlated with resistin levels (r = 0.43; P = 0.02). Patient body mass index (median 26 kg/m(2); range: 18-37) was positively correlated with serum leptin (r = 0.60; P < 0.01) but was not correlated with insulin demand (r = 0.19; P = 0.19), or adiponectin (females: r = -0.37, P = 0.18; males: r = -0.16, P = 0.27), or resistin levels (r = +0.17; P = 0.21).

CONCLUSION

Adiponectin levels and insulin demand were positively correlated during sepsis. Adiponectin levels were negatively correlated with epinephrine demand in male patients and epinephrine demand was positively correlated with resistin levels, which might have increased insulin resistance. The relationship between adiponectin and insulin action in humans is more complex than often suggested.

Hyperthyroidism-associated insulin resistance is not mediated by adiponectin levels

To evaluate the relationship between circulating adiponectin and insulin sensitivity in patients with hyperthyroid Graves' disease, we studied 19 adult patients with this disease and 19 age- and sex-matched euthyroid controls. All hyperthyroid patients were treated with antithyroid drugs and were re-evaluated after thyroid function normalized. Before antithyroid treatment, the adiponectin plasma concentrations were not different comparing with those in control group. The adiponectin levels remained unchanged after treatment. The homeostasis model assessment of insulin resistance (HOMA-IR) in hyperthyroid group was higher before treatment than after treatment. There was no significant difference in serum glucose and insulin levels between hyperthyroid and control groups and in the hyperthyroid group before and after treatment. BMI-adjusted adiponectin levels were not different among three groups. On the other hand, BMI-adjusted insulin levels and HOMA-IR values were significantly decreased after management of hyperthyroidism. Pearson's correlation revealed that insulin and HOMA-IR values positively correlated with triiodothyronine (T3) and free thyroxine (FT4) levels. However, adiponectin did not correlate with T3, FT4, insulin, HOMA-IR and thyrotropin receptor autoantibody (TRAb) levels. In conclusion, insulin resistance associated with hyperthyroidism is not mediated by the levels of plasma adiponectin.

Association of adiponectin with carotid arteriosclerosis in predialysis chronic kidney disease

BACKGROUND/AIMS

Adiponectin is an adipocyte-derived protein with antiatherogenic properties. Chronic kidney disease (CKD) is one of the risk factors for cardiovascular disease. We investigated the potential association between adiponectin and carotid arteriosclerosis in patients with predialysis CKD.

METHODS

We enrolled 95 CKD patients without dialysis and 81 non-CKD patients. Intima-media thickness (IMT) and plaque score (PS) in the common carotid artery were measured using an ultrasound system. Carotid arteriosclerosis was defined as IMT >1.2 mm and/or PS >5.0 mm.

RESULTS

The prevalence of CKD was independently associated with carotid arteriosclerosis after adjustment for other risk factors. Higher adiponectin levels were observed in CKD patients compared with non-CKD patients. Adiponectin levels were not independently correlated with the presence of carotid arteriosclerosis in all subjects. To evaluate the association between adiponectin and carotid arteriosclerosis among a CKD population, we divided the CKD patients into 2 groups according to a cutoff level of adiponectin determined by ROC analysis. The prevalence of carotid arteriosclerosis was significantly higher in the low-adiponectin group than in the high-adiponectin group among CKD patients. After adjusting for other risk factors, low levels of adiponectin were independently correlated with carotid arteriosclerosis in CKD patients.

CONCLUSION

Our data document that adiponectin is associated with increased risk of carotid atherosclerosis in a predialysis CKD population.

Modulation of lupus phenotype by adiponectin deficiency in autoimmune mouse models

Adiponectin is an adipocyte-derived cytokine with anti-inflammatory properties. Paradoxically, circulating adiponectin levels are increased in a number of inflammatory diseases. Thus, we sought to define the role of adiponectin deficiency in mouse models of autoimmunity. Adiponectin-deficient mice on a C57BL/6 background do not develop an autoimmune phenotype. Autoimmunity was also not observed in adiponectin-deficient mice generated on the permissive MRL background. However, adiponectin deficiency exacerbated the autoimmune phenotype of MRL-lpr mice. Compared with MRL-lpr mice, MRL-lpr.apn(-/-) mice displayed greater lymphadenopathy and splenomegaly, as well as increased anti-nuclear antibody and anti-dsDNA production. In addition, evaluation of the kidney revealed larger glomerular tuft size, crescent formation, increased IgG and C3 deposits, and mesangial expansion in the MRL-lpr.apn(-/-) mice. The effects of adiponectin deficiency on the autoimmune phenotypes were more pronounced in female versus male mice. These data show that, while adiponectin deficiency is not sufficient to confer autoimmunity, adiponectin acts as a negative modulator of the autoimmune phenotype in a murine model of lupus.

Adiponectin reduces C-reactive protein expression and downregulates STAT3 phosphorylation induced by IL-6 in HepG2 cells

By playing a direct proatherogenic role, C-reactive protein (CRP) is a potent independent predictor of future cardiovascular events. CRP is predominately synthesized by hepatocytes when stimulated by interleukin-6 (IL-6). In response to IL-6, the signal transducer and activator of transcription 3 (STAT3) becomes phosphorylated on tyrosine and serine residues. Phosphorylated STAT3 then activates CRP gene transcription. In obesity-related disorders such as diabetes, metabolic syndrome, and cardiovascular diseases, the circulating levels of CRP and adiponectin are inversely correlated, suggesting that these two factors might reciprocally regulate each other. We investigated the possibility that adiponectin inhibits CRP production in HepG(2) cells elicited by IL-6. CRP gene expression was determined using ELISA and semi-quantitative RT-PCR, and the phosphorylation of STAT3 was investigated with western blot. Adiponectin reduced IL-6-induced CRP mRNA levels in HepG(2) cells and CRP protein secretion. Preincubating HepG(2) cells with adiponectin led to a decline in STAT3 phosphorylation on both tyrosine and serine residues. Our results demonstrated that adiponectin suppresses CRP synthesis and secretion from HepG(2) cells and suggested that the suppression may be mediated through inhibition of the STAT3 pathway. The finding provides a novel insight into the molecular linkage between obesity and vascular diseases.

Obesity in rheumatoid arthritis

Obesity is a major threat for public health and its study has attracted significant attention in the general population, predominantly due to its association with significant metabolic and cardiovascular complications. In RA research, BMI is frequently reported as a demographical variable, but obesity, as such, has received little interest. This is surprising, in view of the clear associations of obesity with other arthritides, particularly OA, but also in view of the now-clear association of RA with increased cardiovascular morbidity and mortality. In this review, we summarize the studies that have looked into obesity in the RA population, evaluate their findings, identify knowledge gaps and propose directions for future research. We also pose a question of high clinical and research significance: is the use of BMI still a valid way of assessing obesity in RA?

Adiponectin, resistin and IL-6 plasma levels in subjects with diabetic foot and possible correlations with clinical variables and cardiovascular co-morbidity

INTRODUCTION

It is very suggestive that diabetic foot is characterized by a pronounced inflammatory reaction and the pathogenic significance of this inflammation has received little attention. On this basis the aim of our study was to evaluate plasma levels of adiponectin, resistin and IL-6 in subjects with diabetic foot in comparison with subjects without foot complications.

MATERIALS AND METHODS

We recruited 34 subjects with type 2 diabetes mellitus and foot ulceration hospitalized for every condition related to diabetic disease, but not for new vascular events (group A). As controls we recruited 37 patients with type 2 diabetes mellitus without foot ulceration (group B) hospitalized for every condition related to diabetic disease, but not for new vascular events. Adiponectin, Resistin and IL-6 serum levels were evaluated.

RESULTS

Subjects of group A showed lower median plasma levels of adiponectin [7.7450 (4.47-12.17) μg/ml vs 8.480 (5.15-12.87) μg/ml], higher median plasma levels of IL-6 [3.21 (1.23-5.34) pg/ml vs 2.73 (1.24-3.97 pg/ml)] and of resistin [3.860 (2.96-6.29 ng/ml) vs 3.690 (2.,37-6.5 ng/ml)].

CONCLUSION

Our study demonstrated that diabetic subjects with diabetic foot showed in comparison with diabetics without diabetic foot higher IL-6 and resistin plasma levels, lower adiponectin plasma levels.

Influence of smoking and body weight on adipokines in middle aged women

Objective

Quitting smoking was associated with an undesirable weight gain. Both, cigarette smoking and obesity were accompanied by subclinical systemic inflammation. This may cause unfavourable changes in (plasma) adipokine concentration. The aim of the present study was to establish the influence of moderate cigarette smoking on the concentration of the adipokines leptin and adiponectin and the pro-inflammatory factors CRP, SAA, IL-6 and TNF-α in non-obese (n = 138) and obese (n = 175) perimenopausal women of the DRECAN-2005 survey.

Results

Among non-obese women, adiponectin was significantly lower in smokers than in non-smokers (16.88 ± 6.85 vs. 20.63 ± 10.04 μg/ml; P < 0.05). Leptin tended to lower values, too. Among obese women, none significant differences in adiponectin or leptin concentration were observed between smokers and non-smokers. In obese smokers and obese non-smokers, the adiponectin concentrations were significantly lower and the leptin concentrations were significantly higher than in non-obese non-smokers. Non-obese smokers showed significantly higher leukocyte count (6.50 ± 1.83 vs. 5.51 ± 1.31 GPT/l; P < 0.001) and serum amyloid A concentration (7.81 ± 1.25 vs. 4.22 ± 1.43 mg/l; P < 0.05) than non-obese non-smokers. There were only tendencies to higher concentration of CRP, IL-6, and TNF-α. In obese women, moderate cigarette smoking was not associated with higher leukocyte count or concentration of SAA. Among non-smokers, overweight was associated higher concentration of leptin (22.16 ± 12.16 vs. 11.49 ± 6.37 ng/ml; P < 0.001) and with significantly lower concentration of adiponectin (16.29 ± 8.01 vs. 20.77 ± 9.99 μg/ml; P < 0.001). Among smokers, overweight was associated with higher leptin concentration only (obese: 18.62 ± 13.46 vs. non-obese: 8.84 ± 4.92 ng/ml; P < 0.01).

Conclusions

In non-obese middle aged women, even moderate cigarette smoking adversely influences the serum concentration of adiponectin and SAA. Over-weight hides possible effects of smoking on cytokines and adipokines.

Effect of adiponectin deficiency on intestinal damage and hematopoietic responses of mice exposed to gamma radiation

Adiponectin (APN) is an adipose tissue-derived cytokine that regulates insulin sensitivity and inflammation. It is also involved in modulation of cell proliferation by binding to various growth factors. Based on its known effects in modulating cell proliferation and oxidative stress, APN may potentially be involved in regulating tissue damage and repair following irradiation. Adiponectin KO mice and their WT littermates were exposed to a single whole-body dose of 3 or 6Gy gamma radiation. Radiation-induced alterations were studied in jejunum, blood, bone marrow and thymus at days 1 and 5 post-irradiation and compared with sham-irradiated groups. In WT mice, irradiation did not significantly alter serum APN levels while inducing a significant decrease in serum leptin. Irradiation caused a significant reduction in thymocyte cellularity, with concomitant decrease in CD4(+), CD8(+) and CD4(+)CD8(+) T cell populations, with no significant differences between WT and APN KO mice. Irradiation resulted in a significantly higher increase in the frequency of micronucleated reticulocytes in the blood of APN KO compared with WT mice, whereas frequency of micronucleated normochromatic erythrocytes in the bone marrow at day 5 was significantly higher in WT compared with APN KO mice. Finally, irradiation induced similar alterations in villus height and crypt cell proliferation in the jejunum of WT and APN KO mice. Jejunum explants from sham-irradiated APN KO mice produced higher levels of IL-6 compared with tissue from WT animals, but the difference was no longer apparent following irradiation. Our data indicate that APN deficiency does not play a significant role in modulating radiation-induced gastrointestinal injury in mice, while it may participate in regulation of damage to the hematopoietic system.

Inflammation, a link between obesity and cardiovascular disease

Obesity, the most common nutritional disorder in industrialized countries, is associated with an increased mortality and morbidity of cardiovascular disease (CVD). Obesity is primarily considered to be a disorder of energy balance, and it has recently been suggested that some forms of obesity are associated with chronic low-grade inflammation. The present paper focuses on the current status of our knowledge regarding chronic inflammation, a link between obesity and CVDs, including heart diseases, vascular disease and atherosclerosis. The paper discusses the methods of body fat evaluation in humans, the endocrinology and distribution of adipose tissue in the genders, the pathophysiology of obesity, the relationship among obesity, inflammation, and CVD, and the adipose tissue-derived cytokines known to affect inflammation. Due to space limitations, this paper focuses on C-reactive protein, serum amyloid A, leptin, adiponectin, resistin, visfatin, chemerin, omentin, vaspin, apelin, and retinol binding protein 4 as adipokines.

Human gingiva is another site of C-reactive protein formation

OBJECTIVES

C-reactive protein (CRP) is primarily synthesized in the liver. It is hypothesized that human gingiva per se may produce CRP and its expression could be associated with IL-6. This study elucidated the CRP expression profile in human gingiva and its possible association with IL-6.

MATERIALS AND METHODS

Ninety-four gingival biopsies were collected from 44 subjects with chronic periodontitis and 18 periodontally healthy subjects. CRP protein was detected by immunohistochemistry and Western blotting, while CRP and IL-6 mRNAs were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR. CRP protein expression in the reconstituted human gingival epithelia (RHGE) was examined by the particle-enhanced immunoturbidimetric assay and Western blotting.

RESULTS

CRP protein was detected in gingival tissues from patients and healthy subjects by immunohistochemistry and confirmed by Western blotting. Its expression pattern and level at 16 pairs of periodontal pocket tissues and the adjacent clinically healthy tissues from 16 patients were significantly interrelated (r(s)=0.693, p<0.01). CRP mRNA expression was strongly correlated with IL-6 (r=0.694, p<0.001). Both CRP protein and mRNA were detected in the RHGE.

CONCLUSIONS

The present study shows for the first time that human gingiva is able to produce CRP in situ that may be associated with IL-6 activity.

C-reactive protein in gingival crevicular fluid may be indicative of systemic inflammation

BACKGROUND AND AIM

Periodontitis is associated with elevated C-reactive protein (CRP) in both serum and gingival crevicular fluid (GCF). Although the liver is the primary source of CRP, extra-hepatic production of CRP has been reported. This study aimed to determine whether CRP in GCF is produced locally in the gingivae.

MATERIALS AND METHODS

Gingivae and GCF were collected from non-periodontitis and periodontitis sites. Presence of CRP in gingivae was assessed by immunohistochemistry. CRP in GCF was measured using ELISA. Gene expression for CRP in gingivae was determined using real-time polymerase chain reaction.

RESULTS

CRP was found in both the gingivae and GCF. No gingivae had detectable amounts of CRP mRNA. Not all patients with periodontitis had detectable levels of CRP in the GCF. Some non-periodontitis patients had detectable levels of CRP in the GCF.

CONCLUSION

CRP in the GCF appears to be of systemic origin, and therefore may be indicative of systemic inflammation from either a periodontal infection or inflammatory disease elsewhere. The correlation between levels of CRP in GCF and serum requires validation in future studies.

Usefulness of C-reactive protein to high-molecular-weight adiponectin ratio to predict insulin resistance and metabolic syndrome in Japanese men

AIM

We questioned whether the ratio of C-reactive protein to high-molecular-weight adiponectin (C/A ratio), compared to each value alone, is more useful to predict insulin resistance and/or metabolic syndrome.

METHODS

We measured serum CRP and HMW adiponectin levels in 841 Japanese men who had participated in an annual health checkup. Correlations of the C/A ratio with metabolic parameters were assessed, and its predictive values for insulin resistance and MetS were compared with CRP or HMW adiponectin alone.

RESULTS

The C/A ratio was higher in subjects with MetS (n = 114) than in those without MetS (0.46 ± 0.67 vs. 0.23 ± 0.39, p<0.0001). The C/A ratio was correlated with a larger number of metabolic parameters than CRP, but the correlation was comparable to HMW adiponectin. Likewise, the area under the curve of the C/A ratio in receiver operator characteristic analysis for MetS was greater than that of CRP, but comparable to that of HMW adiponectin. However, the AUC of the C/A ratio in ROC analysis for insulin resistance (HOMA-IR >2.5) was greater than that of CRP or HMW adiponectin alone.

CONCLUSION

While the C/A ratio provided little advantage to predict MetS, it might be more useful to predict insulin resistance than CRP or HMW adiponectin alone.

Circulating levels of inflammatory markers in intrauterine growth restriction

We aimed to investigate possible alterations in circulating levels of the perinatal stress markers high sensitivity (hs)-CRP, PAI-1, and S100B--probably reflecting brain and adipose tissue inflammation--in intrauterine growth-restricted-(IUGR) and appropriate-for-gestational-age-(AGA) pregnancies, given that these groups differ in fat mass and metabolic mechanisms involving aseptic inflammation. Serum hs-CRP, PAI-1, and S100B levels were measured in 40 mothers, and their 20 AGA and 20 IUGR full-term fetuses and neonates on postnatal days 1 and 4. hs-CRP, PAI-1, and S100B levels did not differ at all time points between AGA and IUGR groups. We conclude that the lack of difference in hs-CRP, PAI-1 and S100B levels, between IUGR and AGA fetuses/neonates--despite the lower birth weight, reflecting reduced fat mass in the former--might indicate more intense adipose tissue and nervous system inflammation in IUGRs. However, implication of other inflammation-related mechanisms, common in the IUGR state (e.g. preeclampsia), cannot be excluded.

Serum total adiponectin is associated with impaired glucose tolerance in Asian Indian females but not in males

OBJECTIVE

Adiponectin may play a role in the development of type 2 diabetes and cardiovascular disease (CVD). However, little is known about the relationship between adiponectin and impaired glucose tolerance (IGT). We investigated the association between adiponectin and IGT and between adiponectin and cardiovascular risk factors among subjects with IGT.

RESEARCH DESIGN AND METHODS

Subjects with normal glucose tolerance (NGT)(n = 571) and impaired glucose tolerance (n = 167) were recruited from the Chennai Urban Rural Epidemiology Study in south India. Serum total adiponectin levels were measured using a radioimmunoassay (Linco Research, St. Charles, MO). High sensitivity C-reactive protein (hsCRP) was estimated by nephelometry.

RESULTS

In sex-stratified analyses, adiponectin was significantly associated with IGT in females [odds ratio (OR): 0.93, 95% confidence interval (CI): 0.872-0.991, p = 0.026] after controlling for age, waist circumference, blood pressure, alcohol consumption, smoking, lipid profile, and glycemic indices; in males there was no significant association (OR = 0.90, 95% CI: 0.798-1.012, p = 0.078). In prediabetic females, adiponectin was not associated with any CVD risk factors (age, waist circumference, blood pressure, cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, fasting glucose, fasting insulin, and insulin resistance level), but was associated negatively with 2-hour postplasma glucose levels (r = -0.243, p < 0.05) and hsCRP (r = -0.219, p < 0.05) after adjusting for demographic and biomedical indices. No associations with CVD risk factors were observed in males with IGT.

CONCLUSION

Serum total adiponectin levels are associated with IGT, 2-hour postplasma glucose, and hsCRP in Asian Indian females but not in males.

Visceral adipose tissue and inflammation correlate with elevated liver tests in a cohort of overweight and obese patients

OBJECTIVE

To study the relationship between elevated liver tests and high sensitive C-reactive protein (hs-CRP), as potential markers of liver inflammation and non-alcoholic steatohepatitis (NASH), with anthropometric and laboratory parameters in overweight patients, especially the relationship with visceral adipose tissue (VAT).

METHODS

Patients presenting to the obesity clinic were prospectively included. Detailed anthropometry, computed tomography (CT)-measured VAT, liver tests (aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT)) and hs-CRP were assessed, along with an extended series of biochemical parameters.

RESULTS

All 480 patients (gender distribution male (M)/female (F) (10/90%)) with complete data were included. Mean age was 39+/-13 years, mean BMI 34.5+/-6.0 kg m(-2). In 37.3% of the patients one or more of the liver tests were elevated. VAT was positively related to AST (r=0.18, P<0.001), ALT (r=0.29, P<0.001), ALP (r=0.16, P<0.01) and GGT (r=0.39, P<0.001). Comparing subjects with high (VAT>or=113 cm(2)) vs low (VAT<113 cm(2)) VAT levels, significant differences were noted for AST (26+/-12 vs 24+/-12 U l(-1), P=0.003), ALT (37+/-21 vs 31+/-21 U l(-1), P<0.001), ALP (76+/-20 vs 71+/-18 U l(-1), P=0.008), GGT (33+/-20 vs 25+/-15 U l(-1), P<0.001) and hs-CRP (0.62+/-0.43 vs 0.52+/-0.48 mg dl(-1), P<0.001). After correction for BMI the difference in AST and ALP between the high vs low VAT group disappeared. The differences for ALT and GGT remained significant (P=0.008 and P<0.001 respectively). After correction for hs-CRP the four different liver tests remained significantly higher in the high VAT group. A stepwise multiple regression analysis revealed that every single liver test has his own most important determinant; VAT and hs-CRP for AST, insulin resistance calculated with homeostasis model assessment (HOMA-IR) and hs-CRP for ALT and ALP, and triglycerides and VAT for GGT.

CONCLUSION

In overweight and obese patients, liver tests, especially ALT and GGT, are associated with visceral fat mass. After correction for BMI and hs-CRP, ALT and GGT are significantly higher in patients with increased VAT, thereby supporting evidence for a potential key role of VAT in the pathogenesis of non-alcoholic fatty liver disease (NAFLD).

The autocrine and paracrine roles of adipokines

Obesity, defined by an excess of adipose tissue, is often associated with the development of various metabolic diseases. The increased and inappropriate deposition of this tissue contributes to hyperglycemia, hyperlipidemia, insulin resistance, endothelial dysfunction and chronic inflammation. Recent evidence suggests that factors expressed and secreted by the adipose tissue, adipokines, may contribute to the development of these abnormalities by mechanisms including inhibition of adipogenesis, adipocyte hypertrophy and death, immune cell infiltration and disruption of tissue metabolism. The presence of adipokine receptors in adipocytes renders these cells available to autocrine and paracrine effects of adipokines. In this review the reported local effects of adipokines on adipose tissue structure, inflammation and regulation of metabolic functions, in the face of over-nutrition and consequent obesity, are outlined. Elucidating the local regulation of white adipocyte development and function could help in the design of effective, tissue-specific therapies for obesity-associated diseases.

Determinants of adiponectin levels in patients with chronic systolic heart failure

Adiponectin, an adipocytokine, is secreted by adipocytes and mediates antihypertrophic and anti-inflammatory effects in the heart. Plasma concentrations of adiponectin are decreased in the presence of obesity, insulin resistance, and obesity-associated conditions such as hypertension and coronary heart disease. However, a paradoxical increase in adiponectin levels is observed in human systolic heart failure (HF). We sought to investigate the determinants of adiponectin levels in patients with chronic systolic HF. Total adiponectin levels were measured in 99 patients with stable HF and a left ventricular (LV) ejection fraction of <40%. The determinants of adiponectin levels on univariate analysis were included in a multivariate linear regression model. At baseline, 62% of the patients were black, 63% were men, the mean age was 60 + or - 13 years, the LV ejection fraction was 21 + or - 9%, and the body mass index was 30.6 + or - 6.7 kg/m(2). The mean adiponectin level was 15.8 + or - 15 microg/ml. Beta-Blocker use, body mass index, and blood urea nitrogen were significant determinants of adiponectin level on multivariate analysis. The LV mass, structure, and LV ejection fraction were not related to adiponectin levels on multivariate analysis. The effect of beta-blocker therapy was most marked in nonobese patients with a body mass index <30 kg/m(2). In conclusion, in patients with chronic systolic HF, beta-blocker therapy correlated with lower adiponectin levels, especially in nonobese patients. This relation should be taken into account when studying the complex role of adiponectin in patients with chronic systolic HF.

Plasma Pentraxin 3, but not high-sensitivity C-reactive protein, is a useful inflammatory biomarker for predicting cognitive impairment in elderly hypertensive patients

BACKGROUND

Due to the increasing longevity of human populations worldwide, there is need of a useful biomarker for the early detection of cognitive impairment in elderly persons. Both high blood pressure (BP) and inflammatory processes have been reported to be involved in cognitive impairment via cerebrovascular atherosclerosis or neuronal cell damage.

METHODS

In this cross-sectional study of 210 ambulatory elderly hypertensive patients without clinically evident dementia (mean age: 74 years; 44% men), we measured 24-hour BP, circulatory pentraxin 3 (PTX3) and high-sensitivity C-reactive protein (hs-CRP) levels, and cognitive function (Mini-Mental State Examination [MMSE]).

RESULTS

A high plasma PTX3 level was observed in lean subjects, especially in those whose current body weight was lower than that measured 5 years earlier, whereas a high hs-CRP level was associated with obesity (all p < .05). Both PTX3 and hs-CRP levels were significantly associated with the MMSE score (r = -.248, p<0.001 and r = -.153, p<0.05, respectively); however, in multiple regression analysis, the PTX3 level, but not the hs-CRP level, was inversely associated with the MMSE score independently of patient demographics, glucose and lipid metabolic parameters, 24-hour systolic BP (SBP) level, and the atherosclerotic burden (all p < .05). Moreover, there was a significant interaction between the PTX3 and 24-hour SBP levels in the determinants of MMSE score (p < .05).

CONCLUSIONS

A high plasma PTX3 level in elderly hypertensive patients, particularly in those with a high 24-hour BP level, could be a significant predictor of cognitive impairment. A high PTX3 level may be a marker of frailty in elderly hypertensive patients.

Adiponectin promotes macrophage polarization toward an anti-inflammatory phenotype

It is established that the adipocyte-derived cytokine adiponectin protects against cardiovascular and metabolic diseases, but the effect of this adipokine on macrophage polarization, an important mediator of disease progression, has never been assessed. We hypothesized that adiponectin modulates macrophage polarization from that resembling a classically activated M1 phenotype to that resembling alternatively-activated M2 cells. Peritoneal macrophages and the stromal vascular fraction (SVF) cells of adipose tissue isolated from adiponectin knock-out mice displayed increased M1 markers, including tumor necrosis factor-alpha, interleukin-6, and monocyte chemoattractant protein-1 and decreased M2 markers, including arginase-1, macrophage galactose N-acetyl-galactosamine specific lectin-1, and interleukin-10. The systemic delivery of adenovirus expressing adiponectin significantly augmented arginase-1 expression in peritoneal macrophages and SVF cells in both wild-type and adiponectin knock-out mice. In culture, the treatment of macrophages with recombinant adiponectin protein led to an increase in the levels of M2 markers and a reduction of reactive oxygen species and reactive oxygen species-related gene expression. Adiponectin also stimulated the expression of M2 markers and attenuated the expression of M1 markers in human monocyte-derived macrophages and SVF cells isolated from human adipose tissue. These data show that adiponectin functions as a regulator of macrophage polarization, and they indicate that conditions of high adiponectin expression may deter metabolic and cardiovascular disease progression by favoring an anti-inflammatory phenotype in macrophages.

Combined effect of C-reactive protein and stavudine on adipogenesis

BACKGROUND

Subcutaneous fat wasting in HIV therapy is primarily associated with the use of stavudine (d4T) and zidovudine (AZT). We hypothesized that C-reactive protein (CRP) might have an additive effect on nucleoside reverse transcriptase inhibitor (NRTI)-mediated peripheral fat loss.

METHODS

3T3-F442A cells were exposed to AZT (6 microM), d4T (3 microM) and/or CRP (0.5 microg/ml) during differentiation. Differentiation was assessed by real-time PCR measurement of peroxisome proliferator-activated receptor (PPAR)gamma and CCAAT/enhancer-binding protein (C/EBP)alpha, by quantification of triglyceride accumulation and by determination of adiponectin expression and secretion. In addition, parameters of lipid accumulation, lipolysis, cell viability and apoptosis were examined.

RESULTS

When preadipocytes were induced to differentiate in the presence of only AZT, d4T or CRP, only AZT significantly impaired adipogenic differentiation. When combined, d4T+CRP also led to reduced triacylglycerol accumulation, an effect not explained by CRP-induced apoptosis or cell death, but instead confirmed by reduced PPARgamma and C/EBPalpha expression and decreased expression of factors involved in lipogenesis, such as fatty acid synthase and acetyl-coenzyme A carboxylase. We observed further reduction in adiponectin expression and secretion when adipocytes were differentiated in the presence of AZT or d4T together with CRP. Addition of rosiglitazone (1 microM) had no effect on reduced adipogenesis, but partially rescued the effects of d4T and d4T+CRP on adiponectin production.

CONCLUSIONS

We conclude that CRP at levels circulating in patients with HIV infection might promote the anti-adipogenic potential of d4T, a cooperative effect that could account for the in vivo observed variability in the development of lipoatrophy.

C-reactive protein as a predictor of disease in smokers and former smokers: a review

BACKGROUND

Cigarette smoking is a classical and a major risk factor in the development of several diseases with an inflammatory component, including cardiovascular disease and chronic obstructive pulmonary disease. Improvements in assays for protein markers of inflammation have led to many studies on these factors and their roles in disease.

AIMS

C-reactive protein (CRP) is one such marker and this review focuses on the evidence for using CRP as a diagnostic marker and how levels of this protein are modified according to the smoking status of the patient, both in terms of the current amount of cigarettes smoked and how CRP levels change following smoking cessation.

CONCLUSIONS

Assay of CRP levels may be useful in monitoring disease progression and determining risk of future cardiovascular complications. However, as this marker is also an indicator of acute inflammation and challenges to the immune system, some caution must be exercised in interpreting the available data on CRP levels in patients with different chronic comorbidities.

The role of fat topology in the risk of disease

Clustering of multiple risk factors such as impaired glucose metabolism, lipid disorders and hypertension has been shown to be the major background of atherosclerotic diseases, and disease entities such as the metabolic syndrome represent a highly atherogenic state. Although these common risks may generally co-exist by accident in one individual, clustering of multiple risk factors in the metabolic syndrome does not occur by accident, and there should be a key player for the syndrome. In 1983, we reported the method for fat analysis using computed tomography scan, which enables us to analyze intra-abdominal visceral adiposity as well as subcutaneous fat. Visceral fat accumulation has been shown to cause impaired glucose metabolism, lipid disorders, and hypertension, and therefore it is considered to be a key player in the metabolic syndrome. To clarify the mechanism by which visceral fat accumulation causes a variety of metabolic and vascular diseases, we studied the molecular characteristics of adipose tissue and adipocytes by investigating expressed genes in visceral and subcutaneous adipocytes and revealed that adipocytes, especially visceral adipocytes, secrete a variety of bioactive substances, the so-called adipocytokines. We showed that visceral fat accumulation causes abnormalities in adipocytokine secretion, such as hypersecretion of plasminogen activator inhibitor 1, which is related to thrombogenic vascular diseases. More importantly, we discovered an important benign adipocytokine named adiponectin, which protects against the development of diabetes mellitus, hypertension, inflammation, and atherosclerotic vascular diseases. Plasma levels of adiponectin decreased in individuals with visceral fat accumulation, and hypoadiponectinemia caused by visceral fat accumulation might be one of the major causes of metabolic syndrome.

Proinflammatory cytokines in CRP baseline regulation

Low-grade inflammation, a minor elevation in the baseline concentration of inflammatory markers such as C-reactive protein (CRP), is nowadays recognized as an important underlying condition in many common diseases. Concentrations of CRP under 10 mg/1 are called low-grade inflammation and values above that are considered as clinically significant inflammatory states. Epidemiological studies have revealed demographic and socioeconomic factors that associate with CRP concentration; these include age, sex, birth weight, ethnicity, socioeconomic status, body mass index (BMI), fiber consumption, alcohol intake, and dietary fatty acids. At the molecular level, production of CRP is induced by proinflammatory cytokines IL-1, IL-6, and IL-17 in the liver, although extra hepatic production most likely contributes to systemic concentrations. The cytokines are produced in response to, for example, steroid hormones, thrombin, C5a, bradykinin, other cytokines, UV-light, neuropeptides and bacterial components, such as lipopolysaccharide. Cytokines exert their biological effects on CRP by signaling through their receptors on hepatic cells and activating different kinases and phosphatases leading to translocation of various transcription factors on CRP gene promoter and production of CRP protein. Genetic polymorphisms in the interleukin genes as well as in CRP gene have been associated with minor elevation in CRP. As minor elevation in CRP is associated with both inflammatory and noninflammatory conditions, it should be noticed that the elevation might just reflect distressed or injured cells homeostasis maintenance in everyday life, rather than inflammation with classical symptoms of redness, swelling, heat, and pain.

Adiponectin is associated with cardiovascular disease in male renal transplant recipients: baseline results from the LANDMARK 2 study

BACKGROUND

Adiponectin is a major adipocyte-derived protein with insulin-sensitizing, anti-inflammatory and anti-atherogenic properties. Adiponectin levels correlate inversely with renal function and higher levels are predictive of lower cardiovascular disease (CVD) in patients with normal renal function and chronic kidney disease. No data exists on the association between adiponectin and CVD in renal transplant recipients (RTR).

METHODS

Standard biochemistry, clinical data and adiponectin were collected from 137 RTR recruited to the LANDMARK 2 study at baseline. The LANDMARK 2 study is an ongoing randomized controlled study that compares the outcome of aggressive risk factor modification for cardiovascular disease versus standard post-transplant care in renal transplant recipients with impaired glucose tolerance or diabetes mellitus.

RESULTS

Mean patient age was 53.4 +/- 12 years and the median post-transplantation period was 5 (0.5-31.9) years. Mean serum adiponectin level was 12.3 +/- 7.1 microg/mL. On univariate analysis, adiponectin was positively associated with female gender (P = 0.01) and serum high-density lipoprotein (HDL) concentration (P < 0.001), and inversely with body mass index (P = 0.009), metabolic syndrome (P = 0.047), abnormal glucose tolerance (P = 0.01), C-reactive protein (P = 0.001) and serum triglyceride (P < 0.001). On stepwise multivariate analysis, adiponectin in males was negatively correlated with combined baseline CVD (P = 0.03), waist-hip ratio (P = 0.003) and glomerular filtration rate (P = 0.046), and positively with HDL (P < 0.001). In contrast, in females adiponectin was inversely associated with C-reactive protein (P = 0.001) and serum triglyceride.

CONCLUSION

In conclusion, adiponectin is positively correlated with inflammation, dyslipidemia and abnormal glucose tolerance in RTR. Furthermore, hypoadiponectinemia correlated with increased baseline CVD in male RTR.

Plasma leptin and adiponectin in COPD exacerbations: associations with inflammatory biomarkers

BACKGROUND

Various systemic inflammatory markers have been evaluated for their value in acute exacerbations of chronic obstructive pulmonary disease (COPD). Leptin and adiponectin have been linked to acute exacerbations and stable COPD.

OBJECTIVES

To assess plasma leptin, adiponectin and their ratio in acute exacerbations of COPD and to study possible associations with inflammatory biomarkers.

METHODS

Plasma leptin, adiponectin and their ratio (L/A) and serum biomarkers of systemic inflammation C-reactive protein (CRP), Tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) were assessed at three time points (admission, resolution and stable phase - 8 weeks after resolution) in a selected cohort of 63 COPD patients hospitalized for acute exacerbations. Subjects with comorbidities related to adipose tissue hormones were meticulously excluded.

MEASUREMENTS AND MAIN RESULTS

All systemic inflammatory biomarkers, leptin and L/A ratio were elevated during admission compared to resolution and stable phase (mean L/A ratio 2.6 vs. 1.57 vs. 1.22, respectively; p<0.0001), whereas adiponectin was elevated at resolution compared to admission. Log leptin, adiponectin and L/A ratio were significantly associated with variables of systemic inflammation, after proper adjustments, both on admission and in stable condition. In stepwise multiple linear regression models, IL-6 and TNF-alpha present the most significant associations with leptin, adiponectin and their ratio.

CONCLUSIONS

Our data suggest that both leptin and adiponectin are associated with the systemic inflammatory process during exacerbations of COPD. The most significant associations seem to be those with IL-6 and TNF-alpha.

Antiatherosclerotic and anti-insulin resistance effects of adiponectin: basic and clinical studies

Adiponectin is a protein secreted by adipose cells that may couple regulation of insulin sensitivity with energy metabolism and serve to link obesity with insulin resistance. Obesity-related disorders characterized by insulin resistance including the metabolic syndrome, diabetes, atherosclerosis, hypertension, and coronary artery disease are associated with both decreased adiponectin levels and endothelial dysfunction. Recent studies demonstrate that adiponectin has insulin-sensitizing effects as well as antiatherogenic properties. Lifestyle modifications and some drug therapies to treat atherosclerosis, hypertension, diabetes, and coronary heart disease have important effects in increasing adiponectin levels, decreasing insulin resistance, and improving endothelial dysfunction. In this review, we discuss insights into the relationships between adiponectin levels, insulin resistance, and endothelial dysfunction that are derived from various therapeutic interventions. The effects of lifestyle modifications and cardiovascular drugs on adiponectin levels and insulin resistance suggest plausible mechanisms that may be important for understanding and treating atherosclerosis and coronary heart disease.

Obesity and cancer: the role of dysfunctional adipose tissue

Overweight and obesity are health problems of epidemic proportions, increasing the risk not only of cardiovascular disease and type 2 diabetes mellitus but also of various types of cancer. Obesity is strongly associated with changes in the physiological function of adipose tissue, leading to insulin resistance, chronic inflammation, and altered secretion of adipokines. Several of these factors, such as insulin resistance, increased levels of leptin, plasminogen activator inhibitor-1, and endogenous sex steroids, decreased levels of adiponectin, and chronic inflammation, are involved in carcinogenesis and cancer progression. This article reviews these mechanisms, focusing on adipose tissue dysfunction as a unifying causal factor. Although understanding of the link between obesity and cancer might provide therapeutic targets, preventing overweight and obesity still remains number one priority.

Endocrine functions of adipose tissue: focus on adiponectin

Accumulating evidence indicates that obesity and overweight are associated with, and contribute to, the development of type 2 diabetes mellitus (DM), cardiovascular disease (CVD), and chronic kidney disease (CKD). The adipocyte-derived cytokine, adiponectin, has been shown to improve insulin sensitivity, increase rates of fatty acid oxidation, decrease muscle lipid content, and reduce inflammation and vascular injury. However, adiponectin levels have been found to be reduced in persons with obesity and type 2 DM. Furthermore, adiponectin levels are inversely associated with those of tumor necrosis factor-alpha and C-reactive protein-markers of endothelial dysfunction and systemic inflammation. The 2 receptors for adiponectin-Adipo R(1) and Adipo R(2), which are expressed in muscle and liver tissue and in human fat cells-are hormonally regulated, with increased insulin levels causing a reduction in their abundance. The hyperinsulinemia observed in obesity, therefore, may be partially responsible for the reduction in the numbers of adiponectin receptors. Adiponectin aggregates range from a hexamer of low molecular weight to larger multimeric structures of high molecular weight. A smaller proteolytic fragment-the globular head domain of adiponectin, or gAd-interacts specifically with skeletal muscle. The relation of circulating adiponectin to its biologic actions is more complex than originally believed; therefore, it is the multimeric forms of the adiponectin molecule that need to be measured and evaluated in relation to associated metabolic, cardiovascular, and renal functions. Furthermore, strategies to measure the numbers of adiponectin receptors on available tissue need to be developed to fully assess the clinical role of adiponectin in type 2 DM, CVD, and CKD.

Urinary proteins in children with urinary tract infection

The aim of this study was to test our hypothesis that the urinary excretion of C-reactive protein (CRP), alpha 1-microglobulin (A1M), retinol-binding protein (RBP) and Clara cell protein (CC16) is increased in children with urinary tract infection (UTI) and relates to renal damage as measured by acute dimercaptosuccinic acid (DMSA) scintigraphy. Fifty-two children <2 years of age with UTI were enrolled in the study, 44 of whom were febrile. The control group consisted of 23 patients with non-UTI infection and elevated serum CRP (s-CRP) levels. Thirty-six patients had abnormal DMSA uptake, classified as mild, moderate or severe damage (DMSA class 1, 2, 3, respectively). There was a significant association between DMSA class and the excretion of urinary RBP (u-RBP) and u-CC16. There was also a significant difference in u-CRP levels between children with UTI and control children with non-UTI infections, although u-CRP excretion was not significantly correlated to DMSA class. In conclusion, the urinary excretion of the low-molecular-weight proteins RBP and CC16 showed a strong association with uptake defects on renal DMSA scans. The urinary level of CRP seems to distinguish between children with UTI and other febrile conditions. A combination of these biomarkers may be useful in the clinical assessment of children with UTI.

Plasma adiponectin as a predictive factor of survival after a bypass operation for peripheral arterial disease

OBJECTIVE

We investigated an association between adiponectin and long-term survival in patients requiring an arterial bypass operation for peripheral arterial disease.

METHODS

An enzyme-linked immunosorbent assay kit was used to measure plasma adiponectin levels in 49 patients (38 men, 11 women) before they underwent an arterial bypass operation. Median patient age was 70 years (range, 49-90 years). The study excluded patients with hemodialysis requirement, heart failure, malignant neoplasm, or collagen disease. The symptoms at the first visit were severe intermittent claudication in 27 patients (55%) and critical limb ischemia with rest pain or ulcer, or both, in 22 (45%).

RESULTS

Plasma adiponectin levels were a mean 7.8 +/- 5.3 microg/mL (range, 1.0-25.2 microg/mL). Multiple regression analyses revealed that plasma adiponectin was positively correlated with age (r = 0.49, P = .0003) and negatively correlated with body mass index (r = -0.51, P = .0002) and systolic blood pressure (r = -0.41, P = .0059). The Cox proportional hazards model revealed that plasma adiponectin (hazard ratio, 1.30; P = .03) and critical limb ischemia (hazard ratio, 16.67; P = .047) were significant independent predictors of patient survival after a bypass operation.

CONCLUSION

Plasma adiponectin could be indicative of mortality after a bypass operation for patients with advanced peripheral arterial disease.

Changes in serum adiponectin concentrations in critical illness: a preliminary investigation

INTRODUCTION

Adiponectin plays an important role in the regulation of tissue inflammation and insulin sensitivity. Perturbations in adiponectin concentration have been associated with obesity and the metabolic syndrome. Data on adiponectin pathophysiology in critical illness are limited.

METHODS

Twenty three critically ill patients (9 severe sepsis, 7 burns, 7 trauma). Adiponectin assays on Days 3 (D3) and 7 (D7). Simultaneous, cortisol, cortisone and CRP measurements. Data from 16 historical controls were used for comparison.

RESULTS

The mean plasma adiponectin concentration for the ICU cohort on D3 and D7 were not significantly different (4.1 +/- 1.8 and 5.0 +/- 3.3 mcg/ml respectively, P = 0.38). However, these were significantly lower than the mean plasma adiponectin in the control population (8.78 +/- 3.81 mcg/ml) at D3 (P < 0.0001) and D7 (P = 0.002). Plasma adiponectin showed a strong correlation with plasma cortisol in the ICU group on both D3 (R2 = 0.32, P < 0.01) and D7 (R2 = 0.64, 0.001). There was an inverse correlation between plasma adiponectin and CRP on D7, R = -0.35.

CONCLUSIONS

In this preliminary study, critical illness was associated with lower adiponectin concentrations as compared with controls. A significant relationship between plasma cortisol and adiponectin in critically ill patients was evident, both during the early and late phases. These data raise the possibility that adiponectin may play a part in the inflammatory response in patients with severe illness.