Leptin, but not adiponectin, is a predictor of recurrent cardiovascular events in men: results from the LIPID study

Role of inflammation following an acute myocardial infarction: design of INFINITY

After a myocardial infarction, the inflammatory response is connected to major adverse outcomes such as ischemia-reperfusion injury, adverse cardiac remodeling, infarct size and poor prognosis. INFlammatIoN amI sTudY (INFINITY) is a multicenter, prospective, observational, cohort study designed to investigate the prognostic role of the cytokines IL-6, IL-10, IL-18 and IL-17 and the adipokines leptin, apelin and chemerin in patients with acute coronary syndrome. The study will test if these inflammatory biomarkers reflect different clinical manifestations of coronary artery disease and have a prognostic role in a 6-month follow-up period. This study represents an opportunity to investigate further the prognostic role of a selected combination of proinflammatory and anti-inflammatory biomarkers in the prognosis and risk stratification of acute coronary syndrome patients.

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), and the absolute risk of cardiovascular events is similar to people with coronary artery disease. This is an update of a review first published in 2009 and updated in 2014, which included 50 studies (45,285 participants).

OBJECTIVES

To evaluate the benefits and harms of statins compared with placebo, no treatment, standard care or another statin in adults with CKD not requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 4 October 2023. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. An updated search will be undertaken every three months.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on death, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD (estimated glomerular filtration rate (eGFR) 90 to 15 mL/min/1.73 m2) were included.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed the study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous benefits and harms with 95% confidence intervals (CI). The risk of bias was assessed using the Cochrane risk of bias tool, and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 63 studies (50,725 randomised participants); of these, 53 studies (42,752 participants) compared statins with placebo or no treatment. The median duration of follow-up was 12 months (range 2 to 64.8 months), the median dosage of statin was equivalent to 20 mg/day of simvastatin, and participants had a median eGFR of 55 mL/min/1.73 m2. Ten studies (7973 participants) compared two different statin regimens. We were able to meta-analyse 43 studies (41,273 participants). Most studies had limited reporting and hence exhibited unclear risk of bias in most domains. Compared with placebo or standard of care, statins prevent major cardiovascular events (14 studies, 36,156 participants: RR 0.72, 95% CI 0.66 to 0.79; I2 = 39%; high certainty evidence), death (13 studies, 34,978 participants: RR 0.83, 95% CI 0.73 to 0.96; I² = 53%; high certainty evidence), cardiovascular death (8 studies, 19,112 participants: RR 0.77, 95% CI 0.69 to 0.87; I² = 0%; high certainty evidence) and myocardial infarction (10 studies, 9475 participants: RR 0.55, 95% CI 0.42 to 0.73; I² = 0%; moderate certainty evidence). There were too few events to determine if statins made a difference in hospitalisation due to heart failure. Statins probably make little or no difference to stroke (7 studies, 9115 participants: RR 0.64, 95% CI 0.37 to 1.08; I² = 39%; moderate certainty evidence) and kidney failure (3 studies, 6704 participants: RR 0.98, 95% CI 0.91 to 1.05; I² = 0%; moderate certainty evidence) in people with CKD not requiring dialysis. Potential harms from statins were limited by a lack of systematic reporting. Statins compared to placebo may have little or no effect on elevated liver enzymes (7 studies, 7991 participants: RR 0.76, 95% CI 0.39 to 1.50; I² = 0%; low certainty evidence), withdrawal due to adverse events (13 studies, 4219 participants: RR 1.16, 95% CI 0.84 to 1.60; I² = 37%; low certainty evidence), and cancer (2 studies, 5581 participants: RR 1.03, 95% CI 0.82 to 1.30; I² = 0%; low certainty evidence). However, few studies reported rhabdomyolysis or elevated creatinine kinase; hence, we are unable to determine the effect due to very low certainty evidence. Statins reduce the risk of death, major cardiovascular events, and myocardial infarction in people with CKD who did not have cardiovascular disease at baseline (primary prevention). There was insufficient data to determine the benefits and harms of the type of statin therapy.

AUTHORS' CONCLUSIONS

Statins reduce death and major cardiovascular events by about 20% and probably make no difference to stroke or kidney failure in people with CKD not requiring dialysis. However, due to limited reporting, the effect of statins on elevated creatinine kinase or rhabdomyolysis is unclear. Statins have an important role in the primary prevention of cardiovascular events and death in people who have CKD and do not require dialysis. Editorial note: This is a living systematic review. We will search for new evidence every three months and update the review when we identify relevant new evidence. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Prognostic role of inflammatory cytokines and novel adipokines in acute myocardial infarction: An updated and comprehensive review

Acute myocardial infarction (AMI) is one of the major causes of morbidity and mortality worldwide. The inflammation response during and after AMI is common and seems to play a key role in the peri-AMI period, related with ischaemia-reperfusion injury, adverse cardiac remodelling, infarct size and poor prognosis. In this article, we provide an updated and comprehensive overview of the most important cytokines and adipokines involved in the complex pathophysiology mechanisms in AMI, summarizing their prognostic role post-AMI. Data so far support that elevated levels of the major proinflammatory cytokines TNFα, IL-6 and IL-1 and the adipokines adiponectin, visfatin and resistin, are linked to high mortality and morbidity. In contrary, there is evidence that anti-inflammatory cytokines and adipokines as IL-10, omentin-1 and ghrelin can suppress the AMI-induced inflammatory response and are correlated with better prognosis. Mixed data make unclear the role of the novel adipokines leptin and apelin. After all, imbalance of pro-inflammatory and anti-inflammatory cytokines may result in worst AMI prognosis. The incorporation of these inflammation biomarkers in established prognostic models could further improve their prognostic power improving overall the management of AMI patients.

Association of Low Leptin with Poor 3-Month Prognosis in Ischemic Stroke Patients with Type 2 Diabetes

Background

Leptin, an adipokine, has effects on the cardiovascular system with both protective and harmful role. This study aimed to assess the relationship between leptin and 3-month prognosis in ischemic stroke patients with type 2 diabetes.

Patients and Methods

As a prospective single-center observational study, we collected consecutive first-ever acute ischemia stroke with type 2 diabetes mellitus from February 2019 to February 2020. Serum samples were obtained at admission, and leptin serum levels were tested by the ELISA method. Logistic regression models were used to assess leptin's prognostic value to predict the functional outcome and mortality within three months.

Results

Finally, two hundred and eleven patients were included, and the mean leptin serum level was 16.8 (SD. 6.9) ng/mL. At admission, 53.6% of those included patients (N=113) were defined as severe stroke (NIH Stroke Scale [NIHSS]>5). In multivariable models adjusted for other factors, leptin levels<11.6ng/mL (lowest quartile, Q1) related to severe stroke and the risk increased 175% (odds ratios [OR] =2.75; 95% confidence interval [CI]=2.13-3.38; P=0.002). Serum leptin levels on admission in patients with poor outcomes and nonsurvivors were significantly reduced (P<0.001 and P<0.001). Leptin levels <11.6ng/mL (lowest quartile, Q1) related to a higher risk of poor functional impairment (OR=5.13; 95% CI =3.25-6.86; P<0.001) and mortality (OR=3.19; 95% CI =2.03-4.25; P<0.001).

Conclusion

The data shows that leptin serum level is a useful prognostic biomarker in ischemic stroke patients with type 2 diabetes, and this relationship is negative.

Leptin levels are not affected by enalapril treatment after an uncomplicated myocardial infarction, but associate strongly with changes in fibrinolytic variables in men

Leptin, an adipocyte-derived hormone, is involved in the regulation of body weight and is associated with obesity-related complications, notably cardiovascular disease (CVD). A putative link between obesity and CVD could be induction of plasminogen activator inhibitor-1 (PAI-1) synthesis by leptin. In this study, we hypothesized that the beneficial effect of the angiotensin-converting enzyme inhibitor (ACE_i) enalapril on PAI-1 levels is mediated by effects on leptin levels. The association between leptin and components of the fibrinolytic system was evaluated in a non-prespecified post hoc analysis of a placebo-controlled randomized, double-blind trial where the effect of the ACE_i enalapril on fibrinolysis was tested. A total of 46 men and 37 women were randomized to treatment with enalapril or placebo after (median 12 months) an uncomplicated myocardial infarction. At baseline, the participants were stable and had no signs of congestive heart failure. Leptin and fibrinolytic variables (mass concentrations of PAI-1, tissue plasminogen activator (tPA) and tPA-PAI complex) were measured at baseline, and after 10 days, 6 months and 12 months. Enalapril treatment did not change leptin levels, which increased significantly during 1 year of follow-up (p = .007). Changes in leptin levels were strongly associated with changes of tPA mass (p = .001), tPA-PAI complex (p = .003) and of PAI-1 (p = .006) in men, but not in women. Leptin levels are not influenced by treatment with an ACE_i. In contrast, leptin associates strongly with changes in fibrinolytic variables notably with a sex difference, which could be of importance for obesity-related CVD.

Serum leptin is associated with first-ever ischemic stroke, lesion size and stroke severity in a Chinese cohort

OBJECTIVE

Leptin may be associated with cardiovascular disease. We tested to determine whether leptin is a marker for first-ever acute ischemic stroke (AIS) in a nested case-referent study.

METHODS

Consecutive patients with first-ever AIS from May 2017 to December 2017 were included. Referents were matched for sex, age and body mass index. Serum leptin levels and routine tests were examined in both groups.

RESULTS

The median serum level of leptin in the stroke patients was 14.3 (interquartile range [IQR], 7.2-21.7) ng/ml, which was significantly higher (P < 0.001) than in the referents (10.7; 5.7-13.6 ng/ml). There was a positive correlation between serum level of leptin and National Institute of Health Stroke Scale score (r[Spearman] = 0.43, P < 0.001). In addition, serum leptin levels paralleled lesion size. Median serum level of leptin in patients with small lesions, medium lesions and large lesions was 7.3 (IQR, 5.3-14.3) ng/ml, 13.9 (IQR, 7.0-21.3) ng/ml, 20.5 (IQR, 12.4-32.7) ng/ml, respectively (analysis of variance: P < 0.001). In the univariate model matching for sex and age, leptin as a continuous variable was associated with AIS, after adjustment for possible confounders (odds ratio [OR] 1.07, 95% confidence interval [CI]: 1.04-1.11; P < 0.001). After adjusting for all other factors, leptin remained an independent stroke predictor with an adjusted OR of 1.03 (95% CI, 1.00-1.10; P = 0.006). Interestingly, the association between AIS and leptin level was more pronounced among men (adjusted OR = 1.05, 95% CI: 1.01-1.12; P < 0.001) when compared with women (adjusted OR = 1.03, 95% CI: 1.10-1.11; P = 0.009).

CONCLUSION

Serum leptin is associated with first-ever AIS, lesion size and stroke severity in a Chinese cohort.

Association between hyperleptinemia and cardiovascular outcomes in patients with coronary artery disease

Purpose

Hyperleptinemia has been independently associated with human cardiovascular (CV) diseases. Accordingly, we evaluate the association between serum leptin and future CV events in patients with coronary artery disease (CAD).

Patients and methods

This study enrolled 98 patients with CAD from January to December 2012. The primary endpoint included incidences of major adverse CV events and hospitalization. Patients follow-up had been completed on June 30, 2017.

Results

After a median follow-up of 52 months, 43 CV events had occurred. Patients with CV events had higher systolic blood pressure (P = 0.030), total cholesterol (P = 0.034), C-reactive protein (P = 0.018), and serum leptin levels (P = 0.001) than those without CV events. Kaplan–Meier analysis showed greater cumulative incidences of CV events in the high leptin group (median leptin concentration >6.03 ng/mL) than in the low leptin group (log-rank P = 0.012). Multivariate Cox regression analysis showed that triglyceride (HR: 1.010; 95% CI: 1.001–1.018; P = 0.022) and leptin levels (HR: 1.054; 95% CI: 1.026–1.082; P < 0.001) were independently associated with CV events in patients with CAD.

Conclusion

Serum leptin levels could serve as a biomarker for future CV events in patients with CAD.

The role of adipokines as prognostic factors of one-year mortality in hip fracture patients

This study investigated the impact of anthropometric parameters, adiponectin, leptin, homeostatic model assessment for insulin resistance (HOMA-IR), beta-isomerised C-terminal telopeptide of collagen type I (β-CTX), and routine biochemical tests on one-year mortality in hip fracture patients. We found that male patients with high adiponectin, leptin, and β-CTX levels had a 5-fold increase in all-cause one-year mortality.

INTRODUCTION

Several predictors of one-year hip fracture mortality have been identified including advanced age, male sex, low bone mineral density, and preexisting comorbidities. However, the impact of metabolic parameters on hip fracture mortality remains unknown. The aim of this study was to examine the effect of serum leptin and adiponectin levels, as well as other metabolic parameters on all-cause one-year hip fracture mortality.

METHODS

This prospective study included 236 patients of all ages with non-traumatic hip fractures. Anthropometric parameters, adiponectin, leptin, HOMA-IR, β-CTX, and routine biochemical tests were recorded at admission and correlated with one-year mortality by using multivariate Cox proportional hazard models.

RESULTS

The median patient age was 82 (75-87) years, and one-year mortality rate was 28.4%. In univariate analysis, adiponectin, age, β-CTX, and renal function were associated with mortality. However, in a multivariate model, male gender, high β-CTX, adiponectin, and leptin were independently associated with increased mortality. Thus, we constructed a nomogram that included all the latter variables in addition to age. The nomogram predicted mortality with a sensitivity of 74.8% (66.0-82.3) and specificity of 74.4% (57.9-87.0), and had an area under the curve of 0.784. Patients that scored <9.2 had a mortality of 10.1%, while those with >9.2 had a mortality of 49.2% (relative risk 5.4, 95% CI 2.8-10.2, P < 0.001).

CONCLUSION

Male patients with high adiponectin, leptin, and β-CTX levels have a 5-fold increase in all-cause one-year mortality after hip fracture.

Leptin predicts short-term major adverse cardiac events in patients with coronary artery disease

INTRODUCTION

Leptin is an adipose tissue-derived hormone associated with cardiovascular risk factors. We examined whether leptin predicts major adverse cardiac events (MACE) in coronary artery disease (CAD) patients.

METHODS

Fasting plasma leptin levels were measured in 1327 male and 619 female CAD patients. The patients were followed up for two years. The primary endpoint (MACE) was the composite of a hospitalisation for congestive heart failure (CHF) or a cardiac death. The secondary endpoint was the composite of an acute coronary syndrome (ACS) or a stroke.

RESULTS

In regression analysis including established risk variables, high leptin levels were associated with a significantly increased risk of MACE (HR 3.37; 95%CI 1.64-6.90; p = 0.001) and ACS or stroke (HR 1.95; 95%CI 1.29-2.96; p = 0.002). Adding leptin to the risk model for MACE increased the C-index from 0.78 (95%CI 0.71-0.85) to 0.81 (0.74-0.88) and improved classification (NRI 0.36; 95%CI 0.13-0.60; p = 0.002) and discrimination of the patients (IDI 0.016; 95%CI 0.001-0.030; p = 0.031).

CONCLUSIONS

High plasma leptin levels predict short-term occurrence of CHF or cardiac death and ACS or stroke in patients with CAD independently of established risk factors. The possible harmful effects of leptin should be thoroughly investigated. Key messages Leptin is a peptide hormone secreted mainly by adipose tissue. It has been associated with several cardiovascular risk factors. High leptin levels predict the short-term occurrence of congestive heart failure or cardiac death and ACS or stroke in patients with CAD independently of established risk factors. The possible detrimental effects of leptin on the cardiovascular system should be thoroughly investigated.

Prognostic Value of Adipokines in Predicting Cardiovascular Outcome: Explaining the Obesity Paradox

OBJECTIVE

To evaluate the cardiovascular (CV) prognostic value of adipokines in a large prospective cohort of patients participating in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial.

PATIENTS AND METHODS

The effects of the adipokine levels at baseline and change from baseline on the composite outcome (CV death, myocardial infarction, and stroke) were analyzed using unadjusted and fully adjusted Cox models in 2330 patients with type 2 diabetes and coronary artery disease who had participated in the Bypass Angioplasty Revascularization Investigation 2 Diabetes trial (from January 1, 2001, through December 1, 2008).

RESULTS

In a fully adjusted model, baseline leptin and change from baseline leptin were protective for CV events, whereas baseline adiponectin, baseline tumor necrosis factor α (TNF-α), change from baseline TNF-α, baseline C-reactive protein (CRP), and change from baseline CRP were harmful. The effect of baseline leptin on CV events depended on the body mass index (BMI), such that the hazard ratios (HRs) varied between 0.6 and 1.4 across the BMI quintiles (interaction P=.03). The same was true for baseline adiponectin (HR varied from 0.7 to 1.7; interaction P=.01), change from baseline monocyte chemoattractant protein-1 (HR varied from 0.8 to 1.8; interaction P=.03), change from baseline TNF-α (HR varied from 0.9 to 1.4; interaction P=.02), and change from baseline IL-6 (HR varied from 0.7 to 1.8; interaction P=.005).

CONCLUSION

Adipokines are independent predictors of CV events in patients with type 2 diabetes and coronary artery disease. The association between the specific adipokines and CV outcome varies depending on BMI. This reflects the complex pathophysiology of CV disease in obesity and may help explain the "obesity paradox."

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00006305.

Serum Adiponectin and Leptin Concentrations in Relation to Body Fat Distribution, Hematological Indices and Lipid Profile in Humans

The purpose of the study was to evaluate the relationship between serum adiponectin and leptin concentrations and body composition, hematological indices and lipid profile parameters in adults. The study involved 95 volunteers (BMI from 23.3 to 53 kg/m²). Anthropometric parameters were measured: body weight and height, waist and hip circumference, waist-to-hip ratio, body fat mass (BMF), subcutaneous and visceral fat mass (SFM, VFM), lean body mass (LBM), skeletal muscle mass (SMM). In serum we determined adiponectin and leptin concentrations, extracellular hemoglobin, total bilirubin, as well as lipid metabolism (TCh, HDL-Ch, LDL-Ch, TG). Mean adipokine levels were significantly higher in women (p ≤ 0.01), adiponectin significantly negatively correlated with body height and weight, systolic blood pressure and absolute LBM and SMM values. The same relation was observed for erythroid system indicators and lipid indicators. A positive correlation was exceptionally found between adiponectin and HDL-Ch. LEP negatively correlated with some percentage rates (%LBM, %SMM). Only in women, we observed a positive correlation between LEP and body weight, BMI and WHR. Studies on ADPN and the ADPN/LEP ratio as a valuable complementary diagnostic element in the prediction and prevention of cardiovascular diseases need to be continued.

Leptin, adiposity, and mortality: results from the National Health and Nutrition Examination Survey III, 1988 to 1994

OBJECTIVE

To determine whether leptin is related to all-cause and cardiovascular (CV) mortality in older adults.

PATIENTS AND METHODS

Participants 60 years and older with plasma leptin level measurements from the National Health and Nutrition Examination Survey III (1988-1994) and mortality data linked to the National Death Index were included. We created sex-specific tertiles of leptin (men: 4.2-7.7 μg/L; women: 11.5-21.4 μg/L) to identify the effect of leptin on all-cause and CV mortality. We also determined whether leptin predicted mortality in patients with obesity. We classified obesity using 4 possible definitions: body mass index 30 kg/m(2) or greater; body fat 25% or more in men and 35% or more in women; waist circumference 102 cm or greater in men and 88 cm or greater in women; and waist-hip ratio 0.85 or higher in women and 0.95 or higher in men. Sex-specific proportional hazard models were used to assess the effect of leptin on all-cause and CV mortality.

RESULTS

Of 1794 participants, 51.6% were women; the mean age was 70.3±0.4 years, and the follow-up period was 12.5 years with 994 deaths (469 were CV deaths). All-cause mortality in the highest leptin tertile was significant neither in men (hazard ratio [HR], 1.23; 95% CI, 0.93-1.63) nor in women (HR, 0.97; 95% CI, 0.68-1.40). CV mortality was the highest in the highest leptin tertile in men (HR, 1.69; 95% CI, 1.06-2.70) but not in women (HR, 1.21; 95% CI, 0.73-1.98). Evaluating the effect of leptin in subgroups of different obesity definitions, we found that high leptin levels as predict CV mortality in men as measured by waist circumference or body fat.

CONCLUSION

Elevated leptin level is predictive of CV mortality only in men. Leptin may provide additional mortality discrimination in obese men.

Association of leptin levels with pathogenetic risk of coronary heart disease and stroke: a meta-analysis

OBJECTIVE

This meta-analysis aimed to investigate the association of leptin levels with pathogenetic risk of CHD and stroke.

MATERIALS AND METHODS

Studies were identified in the PubMed, Embase, and Springer link database without language restriction. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were used as effect indexes. The association of leptin levels with pathogenetic risk of CHD and stroke, as well as the risk variation of CHD with each additional one unit of leptin level were examined via meta-analysis. The publication bias was assessed via Egger's linear regression test.

RESULTS

Eight nested case-control studies consisting of 1,980 patients and 11,567 controls were included for current meta-analysis. ORs (95% CIs) of association of leptin levels with CHD and stroke was 1.90 (1.06, 3.43), and 2.14 (1.48, 3.08), respectively. In addition, significant result was obtained regarding the risk variation of CHD with each additional one unit of leptin level (OR =1.04, 95% CI =1.00-1.08, P=0.044). There was no significant publication bias as suggested by Egger test outcomes.

CONCLUSION

There was a significant association of leptin with pathogenetic risk of CHD and stroke, and raised leptin levels could significantly increase the pathogenetic risk of CHD.

Adipose tissue and vascular inflammation in coronary artery disease

Obesity has become an important public health issue in Western and developing countries, with well known metabolic and cardiovascular complications. In the last decades, evidence have been growing about the active role of adipose tissue as an endocrine organ in determining these pathological consequences. As a consequence of the expansion of fat depots, in obese subjects, adipose tissue cells develope a phenotypic modification, which turns into a change of the secretory output. Adipocytokines produced by both adipocytes and adipose stromal cells are involved in the modulation of glucose and lipid handling, vascular biology and, moreover, participate to the systemic inflammatory response, which characterizes obesity and metabolic syndrome. This might represent an important pathophysiological link with atherosclerotic complications and cardiovascular events. A great number of adipocytokines have been described recently, linking inflammatory mileu and vascular pathology. The understanding of these pathways is crucial not only from a pathophysiological point of view, but also to a better cardiovascular disease risk stratification and to the identification of possible therapeutic targets. The aim of this paper is to review the role of Adipocytokines as a possible link between obesity and vascular disease.

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease (CVD) is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), for whom the absolute risk of cardiovascular events is similar to people who have existing coronary artery disease. This is an update of a review published in 2009, and includes evidence from 27 new studies (25,068 participants) in addition to the 26 studies (20,324 participants) assessed previously; and excludes three previously included studies (107 participants). This updated review includes 50 studies (45,285 participants); of these 38 (37,274 participants) were meta-analysed.

OBJECTIVES

To evaluate the benefits (such as reductions in all-cause and cardiovascular mortality, major cardiovascular events, MI and stroke; and slow progression of CKD to end-stage kidney disease (ESKD)) and harms (muscle and liver dysfunction, withdrawal, and cancer) of statins compared with placebo, no treatment, standard care or another statin in adults with CKD who were not on dialysis.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 5 June 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on mortality, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD not on dialysis were the focus of our literature searches.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (major cardiovascular events, all-cause mortality, cardiovascular mortality, fatal or non-fatal myocardial infarction (MI), fatal or non-fatal stroke, ESKD, elevated liver enzymes, rhabdomyolysis, cancer and withdrawal rates) with 95% confidence intervals (CI).

MAIN RESULTS

We included 50 studies (45,285 participants): 47 studies (39,820 participants) compared statins with placebo or no treatment and three studies (5547 participants) compared two different statin regimens in adults with CKD who were not yet on dialysis. We were able to meta-analyse 38 studies (37,274 participants).The risk of bias in the included studies was high. Seven studies comparing statins with placebo or no treatment had lower risk of bias overall; and were conducted according to published protocols, outcomes were adjudicated by a committee, specified outcomes were reported, and analyses were conducted using intention-to-treat methods. In placebo or no treatment controlled studies, adverse events were reported in 32 studies (68%) and systematically evaluated in 16 studies (34%).Compared with placebo, statin therapy consistently prevented major cardiovascular events (13 studies, 36,033 participants; RR 0.72, 95% CI 0.66 to 0.79), all-cause mortality (10 studies, 28,276 participants; RR 0.79, 95% CI 0.69 to 0.91), cardiovascular death (7 studies, 19,059 participants; RR 0.77, 95% CI 0.69 to 0.87) and MI (8 studies, 9018 participants; RR 0.55, 95% CI 0.42 to 0.72). Statins had uncertain effects on stroke (5 studies, 8658 participants; RR 0.62, 95% CI 0.35 to 1.12).Potential harms from statin therapy were limited by lack of systematic reporting and were uncertain in analyses that had few events: elevated creatine kinase (7 studies, 4514 participants; RR 0.84, 95% CI 0.20 to 3.48), liver function abnormalities (7 studies, RR 0.76, 95% CI 0.39 to 1.50), withdrawal due to adverse events (13 studies, 4219 participants; RR 1.16, 95% CI 0.84 to 1.60), and cancer (2 studies, 5581 participants; RR 1.03, 95% CI 0.82 to 130).Statins had uncertain effects on progression of CKD. Data for relative effects of intensive cholesterol lowering in people with early stages of kidney disease were sparse. Statins clearly reduced risks of death, major cardiovascular events, and MI in people with CKD who did not have CVD at baseline (primary prevention).

AUTHORS' CONCLUSIONS

Statins consistently lower death and major cardiovascular events by 20% in people with CKD not requiring dialysis. Statin-related effects on stroke and kidney function were found to be uncertain and adverse effects of treatment are incompletely understood. Statins have an important role in primary prevention of cardiovascular events and mortality in people who have CKD.

The impact of estradiol and 1,25(OH)2D3 on metabolic syndrome in middle-aged Taiwanese males

In addition to adipocytokines, estradiol (E2) and vitamin D have been reported to affect insulin sensitivity, glucose homeostasis and body weight. However, studies about the impact of E2 and vitamin D on metabolic syndrome (MetS) are still limited. The aim of this study is to clarify the roles of circulating E2 and vitamin D on the risk of MetS in middle-aged Taiwanese males. A total of 655 male volunteers, including 243 subjects with MetS (mean age: 56.7±5.8 years) and 412 normal controls (mean age: 55.1±3.6 years), were evaluated. Subjects with MetS had significantly lower circulating E2, 1,25(OH)₂D₃, and adiponectin, and higher leptin than those without MetS (P<0.001 for all comparisons). E2 and 1,25(OH)₂D₃ were significantly associated with 4 individual components of MetS; more than adiponectin and leptin that were only associated with 3 individual components. In multivariate regression analysis, E2 (beta = −0.216, P<0.001) and 1,25(OH)₂D₃ (beta = 0.067, P = 0.045) were still significant predictors of MetS independent of adiponectin and leptin. Further large studies are needed to confirm our preliminary results and elucidate the possible mechanism.

Leptin, adiponectin, and short-term and long-term weight loss after a lifestyle intervention in obese children

OBJECTIVE

In overweight children, high leptin levels are independently associated with higher risk for cardiovascular disease, whereas adiponectin seems to be protective against type 2 diabetes and atherosclerosis. The study examines the predictive value of leptin for weight loss after a 4- to 6-wk inpatient therapy and again after 1 y; as well as the association among weight loss, leptin, and adiponectin levels and changes in cardiometabolic risk factors after therapy.

METHODS

Body mass index (BMI), blood pressure, Tanner stage, and cardiometabolic risk factors were studied in 402 children (59.2% females, 13.9 ± 2.3 y, BMI 33.8 ± 5.7 kg/m(2)) before and after a 4-to 6-wk inpatient intervention (exercise, diet, and behavioral therapy) and BMI 1 y later (n = 206).

RESULTS

BMI was reduced from 33.8 ± 5.7 to 30.5 ± 5.1 kg/m(2) (P < 0.001) during the lifestyle intervention and remained unchanged after 1 y. Baseline BMI was positively associated with leptin (r = 0.60; P < 0.001) and cardiometabolic risk factors (blood pressure, high-density lipoprotein [HDL] cholesterol, triglycerides). Baseline leptin was associated with BMI and triglycerides (r = 0.39; P < 0.001), baseline adiponectin with HDL-cholesterol (r = 0.40; P < 0.001). Baseline BMI explained 40.7% of the variance in weight loss during therapy. The combination of BMI, sex, and leptin explained 50.4% of the variance. Neither BMI nor leptin predicted weight changes over the long term.

CONCLUSIONS

Overweight children maintained a substantial amount of weight loss after participation in a short-term inpatient lifestyle intervention. Baseline BMI was positively associated with weight reduction during the intervention, whereas baseline leptin had only a minor predictive value.

Pivotal roles of monocytes/macrophages in stroke

Stroke is an important issue in public health due to its high rates both of morbidity and mortality, and high rate of disability. Hypertension, cardiovascular disease, arterial fibrillation, diabetes mellitus, smoking, and alcohol abuse are all risk factors for stroke. Clinical observations suggest that inflammation is also a direct risk factor for stroke. Patients with stroke have high levels of inflammatory cytokines in plasma, and immune cells, such as macrophages and T-lymphocytes, are noted within stroke lesions. These inflammatory events are considered as a result of stroke. However, recent studies show that plasma levels of inflammatory cytokines or soluble adhesion molecules are high in patients without stroke, and anti-inflammatory therapy is effective at reducing stroke incidence in not only animal models, but in humans as well. Statins have been shown to decrease the stroke incidence via anti-inflammatory effects that are both dependent and independent of their cholesterol-lowering effects. These reports suggest that inflammation might directly affect the onset of stroke. Microglial cells and blood-derived monocytes/macrophages play important roles in inflammation in both onset and aggravation of stroke lesions. We review the recent findings regarding the role of monocytes/macrophages in stroke.

Clinical impact of the leptin to soluble leptin receptor ratio on subclinical carotid atherosclerosis in patients with type 2 diabetes

AIM

The adipocyte-derived hormone leptin plays a key role in the regulation of food intake and energy expenditure. Recent studies have suggested that leptin is also involved in the pathogenesis of obesity-associated atherosclerosis and cardiovascular disease. In this study, we investigated the associations of leptin and the soluble leptin receptor (sOb-R) with atherosclerosis in patients with type 2 diabetes.

METHODS

Three hundred seventeen type 2 diabetic subjects were enrolled in this cross-sectional study. Fasting plasma leptin and sOb-R concentrations were measured by enzyme-linked immunosorbent assays. The intima-media thickness (IMT) of the common carotid artery was measured by ultrasound.

RESULTS

The IMT was significantly associated with sOb-R concentrations, age, diabetes duration, serum creatinine (sCre) levels, and systolic blood pressure (SBP), but not with leptin concentrations or the leptin/sOb-R ratio. The concentrations of leptin (r=0.478, p<0.001) and the sOb-R (r= -0.404, p<0.001) and the leptin/sOb-R ratio (r=0.501, p<0.001) were strongly correlated with IMT in subjects treated with insulin for glycemic control, but not in those treated with diet alone or oral hypoglycemic agents. Multiple regression analysis, including age, sex, diabetes duration, body mass index, SBP, HbA1c, triglycerides, LDL-cholesterol, sCre, smoking, and insulin therapy, revealed that plasma leptin and the leptin/sOb-R ratio were independently associated with IMT in subjects treated with insulin.

CONCLUSIONS

Plasma leptin and the leptin/sOb-R ratio are associated with atherosclerosis in patients with type 2 diabetes on insulin therapy, and these associations were independent of obesity and other cardiovascular risk factors.

Adipokines and thrombosis

1. Obesity is a major risk factor for cardiovascular disease. An increased body mass index (BMI) is associated with venous thromboembolism, myocardial infarction, stroke and stent thrombosis after percutaneous interventions. Studies in mouse models of obesity and induced arterial or venous thrombosis have provided insights into the mechanisms involved. 2. In addition to elevated circulating levels of fibrinogen, factor VII and plasminogen activator inhibitor (PAI)-1, changes in platelet biology and function may underlie the increased (athero) thrombotic risk in obesity. These include elevated platelet counts, an increase in mean platelet volume, an increased platelet aggregatory response to agonists and a reversible resistance to the anti-aggregatory effects of nitric oxide and prostacyclin I(2) . 3. Specific adipokines mediate the prothrombotic state in obesity. Of these, leptin enhances both arterial and venous thrombosis by promoting platelet adhesion, activation and aggregation. Leptin also induces tissue factor expression by human neutrophils and other cells. C-Reactive protein enhances the formation of monocyte-platelet aggregates and also promotes P-selectin expression and platelet adhesion to endothelial cells. Further, the adipose tissue is a significant source of tissue factor and PAI-1. Conversely, the circulating levels of adiponectin, a hormone that exerts vasculoprotective, anti-atherosclerotic and antithrombotic effects, are reduced in obese individuals. 4. A better understanding of the interactions of the adipose tissue with circulating and vascular cells and the dissection of the mechanisms linking adipokines to arterial and venous thrombosis may identify obese individuals at particularly high cardiovascular risk and indicate promising vasculoprotective and therapeutic targets.

Sleep disturbances and depressed mood: a harmful combination associated with increased leptin levels in women with normal weight

Leptin, involved in energy regulation and contributor to cardiovascular disease, has been implicated to play a role in depression and sleep disturbances, two closely intertwined conditions. Previous results investigating leptin level alterations either in sleep disorders or in depression have been inconsistent. We investigate the association between leptin levels and the different combinations of depressed mood and sleep disturbances in 1369 subjects (706 men, 663 women), derived from the population-based MONIKA/KORA study. As leptin regulation is known to differ by sex and weight, analyses were performed in normal weight and overweight men and women separately. We found a highly significant association between leptin levels and the combination of depressed mood and sleep disturbances in normal-weight women (BMI ≤ 25) (p<0.01). No associations were found in men and in overweight women. Our results suggest that leptin regulation in depressed mood and sleep disturbances very much depend on sex and weight.

N-terminal pro-B-type natriuretic peptide in early and advanced phases of obesity

BACKGROUND

Increased plasma amino-terminal-cleavage-fragment of NP (NT-proBNP) is an established indicator for heart failure. Moreover, obese adults had low circulating NT-proBNP suggesting an obesity-related dysregulation (natriuretic handicap). Secretion and/or clearance of NT-proBNP were discussed to be impaired in obesity. As only older adults were investigated so far, it remains unclear when during the evolution of obesity the state of a natriuretic handicap develops, and whether NT-proBNP may still serve as a relevant cardiac marker in obese juveniles.

METHODS

We analysed NT-proBNP in juvenile (n=274, 10-18 years) and middle-aged (n=277, 18-50 years) normal weight (n=213) and obese (n=338) probands together with complex anthropometry, carotis sonography, clinical, and laboratory parameters.

RESULTS

NT-proBNP showed a significant gender and age interaction. Adult females had significant higher NT-proBNP than adult males, and higher levels than juvenile females. Adult males had lower levels than juvenile males. Only a weak age and weight interaction was seen with obese juveniles which showed higher NT-proBNP than obese adults. Moreover, normal weight probands had higher NT-proBNP than overweight and obese. In a multiple regression including all probands, gender, creatinine and uric acid were the best predictors for NT-proBNP. In adults, female gender is the strongest driver for increased NT-proBNP.

CONCLUSIONS

These results argue against an essential influence of obesity to B-type cardiac natriuretic hormone system regulation in the absence of heart failure, and suggest NT-proBNP as a useful cardiac marker irrespective of age and obesity.

Prospective, randomized, single-blind comparison of effects of 6 months' treatment with atorvastatin versus pravastatin on leptin and angiogenic factors in patients with coronary artery disease

Leptin has been reported to exert an atherosclerotic effect by regulating expression of angiogenic factors that have been implicated in the pathogenesis of coronary artery disease (CAD). The purpose of this study was to investigate whether lipid-lowering therapy (LLT) with statins could affect leptin levels and angiogenic factors in patients with CAD. This study included 76 patients with CAD and 15 subjects without CAD (non-CAD). CAD patients were randomized to 6 months of intensive LLT with atorvastatin or moderate LLT with pravastatin. Plasma leptin, angiopoetin-2 (Ang-2), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) levels were measured prior to statin therapy (baseline) and after 6 months. Baseline levels of leptin, Ang-2, HGF and VEGF were higher in the CAD group than in the non-CAD group (all P < 0.05). Treatment with intensive LLT decreased leptin, Ang-2, HGF and VEGF levels, whereas moderate LLT did not change these levels. This study suggests that LLT with atorvastatin decreases leptin levels and angiogenic factors in patients with CAD, possibly contributing to the beneficial effects of LLT with atorvastatin in CAD.

Social isolation and depressed mood are associated with elevated serum leptin levels in men but not in women

BACKGROUND

Leptin, involved in energy homeostasis and a predictor of cardiovascular disease, has recently been recognized as mediator in stress reactions. We aimed to explore the association between leptin levels and two stress-related conditions, social isolation and depressed mood, both associated with increased cardiovascular mortality.

METHODS

We analysed leptin levels in 1229 subjects (643 men, 586 women), derived from the population-based MONIKA/KORA study. Standardized questionnaires were used to assess depressive mood and social isolation. In a multiple linear regression adjusted for body weight, age and survey, the association between leptin, social isolation and depressed mood and its interaction was explored in men and women separately. Leptin was then dichotomized and four analyses, adjusted for age, BMI, lifestyle factors, psychosomatic complaints and metabolic variables were performed to compare the risk of elevated leptin levels in the risk groups.

RESULTS

Increased leptin levels were associated with social isolation (p=0.04) and the interaction between social isolation and depressed mood (p=0.02) in men but not in women. In socially isolated and depressed men, leptin levels (mean: 6.07 ng/ml) were significantly increased compared to neither depressed nor isolated men (mean: 4.51 ng/ml, p=0.04). In the multivariate adjusted logistic regression model, the combination of depressed state and social isolation was associated with a 4-fold increased risk (p<0.001) for elevated leptin levels.

CONCLUSION

The finding of elevated leptin levels in socially isolated and depressed men raises the possibility that increased cardiovascular mortality in socially isolated men is partially mediated by hyperleptinemia.

The synovial fluid adiponectin-leptin ratio predicts pain with knee osteoarthritis

The relationship between adipokines, such as leptin and adiponectin, and cartilage degeneration is being increasingly recognized. We asked what the relationship is between these hormones and patient-reported knee osteoarthritis (OA) pain. We collected demographic data, Short Form McGill Pain scores, Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scores, and synovial fluid (SF) samples from 60 consecutive patients with severe knee OA at the time of joint replacement surgery. SF samples were analyzed for leptin and adiponectin using specific ELISA. Non-parametric correlations and linear regression modeling were used to identify the relationship between the adipokines and pain levels. The correlations between the individual adipokines and the pain scales were low to moderate and consistently less than that for the corresponding adiponectin/leptin (A/L) ratio. Linear regression modeling showed that the A/L ratio was a significant predictor of a greater level of pain on the MPQ-SF (p=0.03) but not the WOMAC pain scale (p=0.77). A greater A/L ratio was associated with less pain with severe knee OA and this metabolic pathway may represent a target for novel therapeutics.

Leptinemia and its association with stroke and coronary heart disease in the Jackson Heart Study

BACKGROUND

To examine the association of increased plasma leptin concentration with prevalent stroke and coronary heart disease (CHD) and to examine the genetic contributions of leptin to this association in the Jackson Heart Study cohort.

METHODS

A cohort of 5170 participants aged 21-84 years who underwent Exam I during 2000-2004 was analysed. Odds ratios (OR) of prevalent stroke and CHD were calculated using a logistic regression model adjusted for age, smoking, hypertension and waist circumference (WC). Variance component analysis was used to partition the phenotypic variance of leptin into the polygenic and environmental components.

RESULTS

The prevalence of stroke and CHD was 4.04% and 5.85% in women, and 4.88% and 8.92% in men, respectively. Body mass index (BMI) and WC were highly correlated with leptin both in men and women. In multivariate analysis stratified by sex, leptin was significantly associated with stroke (OR = 1.97, 95% CI = 1.21-3.21) in women after adjustment for age, smoking, systolic blood pressure, BMI and WC (P = 0.0079). No significant association was observed in men. Heritability of sex-, age-adjusted log-transformed leptin for this cohort was 38.0% and 37.8% after further adjustment for WC and hypertension, respectively. In addition, a sibship effect was also found to be significant and explained 12.2% of the total variance of leptin (P = 0.007).

CONCLUSION

There is a significant association of leptin with stroke in women, which is partly influenced by the genetic factor. The findings suggest that leptinemia is an independent risk factor for stroke in African American women.

Disruption of protein kinase A in mice enhances healthy aging

Mutations that cause a reduction in protein kinase A (PKA) activity have been shown to extend lifespan in yeast. Loss of function of mammalian RIIbeta, a regulatory subunit of PKA expressed in brain and adipose tissue, results in mice that are lean and insulin sensitive. It was therefore hypothesized that RIIB null (RIIbeta(-/-)) mice would express anti-aging phenotypes. We conducted lifespan studies using 40 mutant and 40 wild type (WT) littermates of equal gender numbers and found that both the median and maximum lifespans were significantly increased in mutant males compared to WT littermates. The median lifespan was increased from 884 days to 1005 days (p = 0.006 as determined by the log rank test) and the 80% lifespan (defined here as 80% deaths) was increased from 941 days to 1073 days (p = 0.004 as determined by the Wang-Allison test). There was no difference in either median or 80% lifespan in female genotypes. WT mice of both genders became increasingly obese with age, while mutant mice maintained their lean phenotype into old age. Adiposity was found to correlate with lifespan for males only. 50% of male mice between 30 and 35 g, corresponding to about 5% body fat, for either genotype lived over 1000 days. No male mouse outside of this weight range achieved this lifespan. During their last month of life, WT mice began losing weight (a total of 8% and 15% of body weight was lost for males and females, respectively), but RIIbeta(-/-) male mice maintained their lean body mass to end of life. This attenuation of decline was not seen in female mutant mice. Old male mutant mice were insulin sensitive throughout their life. Both genders showed modestly lower blood glucose levels in old mutants compared to WT. Male mutants were also resistant to age-induced fatty liver. Pathological assessment of tissues from end of life male mutant mice showed a decrease in tumor incidence, decreased severity of renal lesions, and a trend towards a decrease in age-related cardiac pathology. These findings help establish the highly conserved nature of PKA and suggest that disruption of PKA affects physiological mechanisms known to be associated with healthy aging.

HIV increases markers of cardiovascular risk: results from a randomized, treatment interruption trial

OBJECTIVES

Plasma soluble inflammatory molecules are associated with the risk of ischaemic cardiovascular events. We investigated whether HIV replication modified the levels of these proteins in a combination antiretroviral therapy (cART) interruption trial.

METHOD AND RESULTS

In 145 HIV-infected Thai patients (62% women, median CD4 cell count 271 cells/microl, median plasma HIV-RNA 4.66 log10 copies/ml) included in the Swiss-Thai-Australia Treatment Interruption Trial (STACCATO) trial, leptin, adiponectin, C-reactive protein, soluble vascular cell adhesion molecule-1 (s-VCAM-1), P-selectin, chemokine ligand 2, chemokine ligand 3, interleukin (IL)-6, IL-10, granulocyte macrophage colony-stimulating factor and D-dimer were measured before cART was initiated, after cART had suppressed HIV replication to less than 50 copies/ml plasma (median 8 months) and again 12 weeks after randomization to continued cART (n=48) or interrupted cART (n=97). Multiple linear regression and logistic regression were used to investigate the association between each cardiovascular marker and plasma HIV-RNA. Initiation of cART resulted in significant declines in s-VCAM-1, P-selectin, leptin and D-dimer, whereas mediators with anti-inflammatory properties, such as adiponectin and IL-10, increased. At 12 weeks after randomization, we found positive associations between levels of s-VCAM-1 and chemokine ligand 2 with an increase in plasma HIV-RNA (r=0.271, P=0.001 and r=0.24, P=0.005, respectively), whereas levels of adiponectin decreased for each 1 log increase in plasma HIVRNA (r=-0.24, P=0.002). Detectable IL-10 was less likely (odds ratio = 0.64, 95% confidence interval = 0.43-0.96) for each 1 log increase in plasma HIV-RNA.

CONCLUSION

Plasma levels of several inflammatory, anti-inflammatory and endothelial activation markers of cardiovascular disease are associated with HIV-RNA replication.