Adiposity, adipokines, and risk of incident stroke in older men

Fluid biomarkers of the neurovascular unit in cerebrovascular disease and vascular cognitive disorders: A systematic review and meta-analysis

Background

The disruption of the neurovascular unit (NVU), which maintains the integrity of the blood brain barrier (BBB), has been identified as a critical mechanism in the development of cerebrovascular and neurodegenerative disorders. However, the understanding of the pathophysiological mechanisms linking NVU dysfunction to the disorders is incomplete, and reliable blood biomarkers to measure NVU dysfunction are yet to be established. This systematic review and meta-analysis aimed to identify biomarkers associated with BBB dysfunction in large vessel disease, small vessel disease (SVD) and vascular cognitive disorders (VCD).

Methods

A literature search was conducted in PubMed, EMBASE, Scopus and PsychINFO to identify blood biomarkers related to dysfunction of the NVU in disorders with vascular pathologies published until 20 November 2023. Studies that assayed one or more specific markers in human serum or plasma were included. Quality of studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Effects were pooled and methodological heterogeneity examined using the random effects model.

Results

A total of 112 studies were included in this review. Where study numbers allowed, biomarkers were analysed using random effect meta-analysis for VCD (1 biomarker; 5 studies) and cerebrovascular disorders, including stroke and SVD (9 biomarkers; 29 studies) while all remaining biomarkers (n = 17 biomarkers; 78 studies) were examined through qualitative analysis. Results of the meta-analysis revealed that cerebrospinal fluid/serum albumin quotient (Q-Alb) reliably differentiates VCD patients from healthy controls (MD = 2.77; 95 % CI = 1.97-3.57; p < 0.0001) while commonly measured biomarkers of endothelial dysfunction (VEGF, VCAM-1, ICAM-1, vWF and E-selectin) and neuronal injury (NfL) were significantly elevated in vascular pathologies. A qualitative assessment of non-meta-analysed biomarkers revealed NSE, NfL, vWF, ICAM-1, VCAM-1, lipocalin-2, MMP-2 and MMP-9 levels to be upregulated in VCD, although these findings were not consistently replicated.

Conclusions

This review identifies several promising biomarkers of NVU dysfunction which require further validation. A panel of biomarkers representing multiple pathophysiological pathways may offer greater discriminative power in distinguishing possible disease mechanisms of VCD.

D-dimer and the risk of hypertension: The REasons for Geographic And Racial Differences in Stroke Cohort Study

Background

Reasons for increased risk of hypertension in Black compared with White people are only partly understood. D-dimer, a thrombo-inflammatory marker higher in Black individuals, is also higher in people with hypertension. However, the impact of D-dimer on racial disparities in risk of incident hypertension has not been studied.

Objectives

To assess whether D-dimer is associated with the risk of incident hypertension, whether the association between D-dimer and the risk of incident hypertension differs by race, and whether the biology reflected by D-dimer explains racial disparities in the risk of incident hypertension.

Methods

This study included 1867 participants in the REasons for Geographic And Racial Differences in Stroke cohort study without baseline hypertension and with a second visit 9.4 years after baseline. Risk ratios of incident hypertension by baseline D-dimer level were estimated, a D-dimer-by-race interaction was tested, and the mediating effect of D-dimer (which represents underlying biological processes) on the association of race and hypertension risk was assessed.

Results

The risk of incident hypertension was 47% higher in persons in the top quartile than in those in the bottom quartile of D-dimer (risk ratio [RR]: 1.47; 95% CI: 1.23-1.76). The association was partly attenuated after adjusting for sociodemographic and adiposity-related risk factors (RR: 1.22; 95% CI: 1.02-1.47). The association of D-dimer and hypertension did not differ by race, and D-dimer did not attenuate the racial difference in the risk of incident hypertension.

Conclusion

D-dimer concentration reflects pathophysiology related to the development of hypertension. Specific mechanisms require further study and may involve adiposity.

The relationship between body mass index and stroke: a systemic review and meta-analysis

BACKGROUND

Stroke is an acute cerebrovascular event closely related to brain tissue damage, and is one of the major causes of death and disability in worldwide. Various studies have reported the effects of body mass index (BMI) on the risk of stroke, but the results remain varied and these results have not been synthesized. Therefore, a meta-analysis was performed to evaluate the relationship between BMI and the risk of stroke.

OBJECTIVES

This systematic review was conducted to explore the relationship between BMI and the risk of stroke.

METHODS

PubMed, EMBASE, Web of Science and Cochrane Library, China Knowledge Resource Integrated Database (CNKI), WanFang Database, Chinese Biomedical Database (CBM), and CQVIP were comprehensively searched for studies exploring the relationship between BMI and stroke from inception to December 1, 2021.

RESULTS

This review included 24 studies involving 5,798,826 subjects. The results of meta-analysis showed that the pooled RR of stroke risk was 0.93 (95% confidence interval [CI] 0.82-1.06, I² = 88.8%, P = 0.29) for the underweight group. Higher BMI (overweight or obese group) was associated with an increased overall risk of stroke, with pooled RR values of 1.25 (95% CI 1.16-1.34, I² = 84.8%, P = 0.00) and 1.47 (95% CI: 1.02-2.11, I² = 99.4%, P = 0.04).

CONCLUSION

The risk of stroke was positively correlated with BMI, and the association was stronger in male and ischemic stroke. Lowering BMI can be used as a way to prevent stroke, and for people who are overweight or obese, lowering body weight can reduce the risk of stroke.

The Role of Biomarkers in Atherothrombotic Stroke-A Systematic Review

Stroke represents the primary debilitating disease in adults and is the second-highest cause of death worldwide. Atherosclerosis, the most prevalent etiology for vascular conditions, is a continuous process that gradually creates and develops endothelial lesions known as atherosclerotic plaques. These lesions lead to the appearance of atherothrombotic stroke. In the last decades, the role of biological biomarkers has emerged as either diagnostic, prognostic, or therapeutic targets. This article aims to create a list of potential biomarkers related to atherothrombotic stroke by reviewing the currently available literature. We identified 23 biomarkers and assessed their roles as risk factors, detection markers, prognostic predictors, and therapeutic targets. The central aspect of these biomarkers is related to risk stratification, especially for patients who have not yet suffered a stroke. Other valuable data are focused on the predictive capabilities for stroke patients regarding short-term and long-term prognosis, including their influence over the acute phase treatment, such as rt-PA thrombolysis. Although the role of biomarkers is anticipated to be of extreme value in the future, they cannot yet compete with traditional stroke neuroimaging markers but could be used as additional tools for etiological diagnosis.

Relation of Adiponectin to Cardiovascular Events and Mortality in Patients With Acute Coronary Syndrome

The association between serum adiponectin levels and cardiovascular events, particularly how adiponectin predicts the development of cardiovascular events and mortality in acute coronary syndrome (ACS) patients remains unresolved. Hence, we aimed to determine whether higher adiponectin levels predict cardiovascular events and mortality in these patients. Regression analyses were performed to clarify adiponectin's ability to predict cardiovascular events and mortality among 1,641 ACS patients. Subgroup analyses were performed according to gender, age, and body mass index (BMI). The primary end point was a composite of the first all-cause death, nonfatal myocardial infarction, or nonfatal stroke event. The secondary end point was all-cause death. Hazard ratios for the primary and secondary end points per 5-µg/ml increase in adiponectin levels were 1.31 (95% confidence interval [CI], 1.13 to 1.47; p = 0.0007) and 1.32 (95% CI, 1.13 to 1.51; p = 0.001), respectively. Higher adiponectin levels were associated with increased cardiovascular events in men, patients aged ≥65 years, and those with BMI <25 kg/m². In conclusion, higher adiponectin levels were associated with increased cardiovascular events and all-cause mortality in ACS patients. Its predictive ability might be limited in women, patients aged <65 years, and patients with BMI ≥25 kg/m².

Leptin in Leanness and Obesity: JACC State-of-the-Art Review

Leptin has emerged over the past 2 decades as a key hormone secreted by adipose tissue that conveys information on energy stores. Leptin is considered an important regulator of both neuroendocrine function and energy homeostasis. Numerous studies (mainly preclinical and much less in humans) have investigated the mechanisms of leptin's actions both in the healthy state as well as in a wide range of metabolic diseases. In this review, the authors present leptin physiology and review the main findings from animal studies, observational and interventional studies, and clinical trials in humans that have investigated the role of leptin in metabolism and cardiometabolic diseases (energy deficiency, obesity, diabetes, cardiovascular diseases, nonalcoholic fatty liver disease). The authors discuss the similarities and discrepancies between animal and human biology and present clinical applications of leptin, directions for future research, and current approaches for the development of the next-generation leptin analogs.

Abdominal obesity and risk of CVD: a dose-response meta-analysis of thirty-one prospective studies

This meta-analysis aimed to study the relationship between abdominal obesity and the risk of CVD by waist circumference (WC), waist:hip ratio (WHR) and waist:height ratio (WHtR). We systematically searched PubMed, Embase and Web of Science. Prospective studies that estimated cardiovascular events by WC, WHR and WHtR were included in this study. Pooled relative risks with 95 % CI were calculated using random effects models. A total of thirty-one studies were included in the meta-analysis, including 669 560 participants and 25 214 cases. Compared the highest with the lowest category of WC, WHR and WHtR, the summary risk ratios were 1·43 (95 % CI, 1·30, 1·56, P < 0·001), 1·43 (95 % CI, 1·33, 1·54, P < 0·001) and 1·57 (95 % CI, 1·37, 1·79, P < 0·001), respectively. The linear dose-response analysis revealed that the risk of CVD increased by 3·4 % for each 10 cm increase of WC, and by 3·5 and 6·0 % for each 0·1 unit increase of WHR and WHtR in women, respectively. In men, the risk of CVD increased by 4·0 % for each 10 cm increase of WC, and by 4·0 and 8·6 % for each 0·1 unit increase of WHR and WHtR, respectively. Collectively, abdominal obesity is associated with an increased risk of CVD. WC, WHR and WHtR are good indicators for the prediction of CVD.

Leptin and its actions on reproduction in males

Leptin, an adipocyte-derived hormone, serves numerous physiological functions in the body, particularly during puberty and reproduction. The exact mechanism by which leptin activates the gonadotropin-releasing hormone (GnRH) neurons to trigger puberty and reproduction remains unclear. Given the widespread distribution of leptin receptors in the body, both central and peripheral mechanisms involving the hypothalamic-pituitary-gonadal axis have been hypothesized. Leptin is necessary for normal reproductive function, but when present in excess, it can have detrimental effects on the male reproductive system. Human and animal studies point to leptin as a link between infertility and obesity, a suggestion that is corroborated by findings of low sperm count, increased sperm abnormalities, oxidative stress, and increased leptin levels in obese men. In addition, daily leptin administration to normal-weight rats has been shown to result in similar abnormalities in sperm parameters. The major pathways causing these abnormalities remain unidentified; however, these adverse effects have been attributed to leptin-induced increased oxidative stress because they are prevented by concurrently administering melatonin. Studies on leptin and its impact on sperm function are highly relevant in understanding and managing male infertility, particularly in overweight and obese men.

Role of Leptin in Acute Ischemic Stroke

Purpose

Leptin has been implicated as a pathogenetic contributor to atherosclerosis. We aimed to investigate the association of leptin level with ischemic stroke.

Materials and Methods

We prospectively enrolled 52 patients with acute ischemic stroke and measured leptin levels and compared with age- and sex-matched healthy controls. Risk factors, body mass index (BMI), biochemical parameters, intima-media thickness (IMT) on carotid vertebral Doppler and neuroimaging was done. Data were entered into MS-Excel and appropriate statistical analysis was done using SPSS software version 21.0. P = 0.05 was considered statistically significant.

Results

Serum leptin was significantly elevated in stroke patients (6598.1 ± 1035.1) compared to controls (3090.7 ± 698.86) (P < 0.01). Patients had higher BMI (26.9 ± 1.7) than controls (26.9 ± 1.7) (P < 0.00). BMI, total cholesterol, low-density lipoprotein (LDL) cholesterol, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C reactive protein (CRP) were significantly elevated in stroke patients than controls. Correlation analysis among patient group showed that serum leptin positively correlated with CRP (r - 0.41, P - <0.05), WBCs (r - 0.28, P - <0.05), ESR (r - 0.429, P - <0.01) total cholesterol (r - 0.31, P - <0.05), LDL-cholesterol (r - 0.19, P - <0.05), and IMT (r - 0.714, P - <0.001).

Conclusion

Our study showed high leptin levels in patients with stroke. Stroke patients with high leptin had higher BMI and inflammatory markers. The results of our study indicate that leptin may have a role in atherosclerosis mediated through inflammation. Future research should be directed toward understanding the role of leptin in the pathogenesis of cerebrovascular diseases and its potential role in preventive treatment of ischemic stroke.

Leptin, cardiovascular diseases and type 2 diabetes mellitus

Leptin, an adipokine that is implicated in the control of food intake via appetite suppression, may also stimulate oxidative stress, inflammation, thrombosis, arterial stiffness, angiogenesis and atherogenesis. These leptin-induced effects may predispose to the development of cardiovascular diseases. In the present review we discuss the evidence linking leptin levels with the presence, severity and/or prognosis of both coronary artery disease and non-cardiac vascular diseases such as stroke, carotid artery disease, peripheral artery disease (PAD) and abdominal aortic aneurysms (AAA) as well as with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). Leptin levels have been positively associated with the presence, severity, extent and lesion complexity of coronary atherosclerosis as well as with the presence, severity and poor clinical outcomes of both ischemic and hemorrhagic strokes. But conflicting results also exist. Furthermore, leptin was reported to independently predict common carotid intima-media thickness and carotid plaque instability. A link between hyperleptinemia and PAD has been reported, whereas limited data were available on the potential association between leptin and AAA. Elevated leptin concentrations have also been related to CKD incidence and progression as well as with insulin resistance, T2DM, micro- and macrovascular diabetic complications. Statins and antidiabetic drugs (including sitagliptin, metformin, pioglitazone, liraglutide and empagliflozin) may affect leptin levels. Further research is needed to establish the potential use (if any) of leptin as a therapeutic target in these diseases.

Ischemic stroke and select adipose-derived and sex hormones: a review

Ischemic stroke is the fifth leading cause of death in the USA and is the leading cause of serious, long-term disability worldwide. The principle sex hormones (estrogen, progesterone, and testosterone), both endogenous and exogenous, have profound effects on various stroke outcomes and have become the focus of a number of studies evaluating risk factors and treatment options for ischemic stroke. In addition, the expression of other hormones that may influence stroke outcome, including select adipose-derived hormones (adiponectin, leptin, and ghrelin), can be regulated by sex hormones and are also the focus of several ischemic stroke studies. This review aims to summarize some of the preclinical and clinical studies investigating the principle sex hormones, as well as select adipose-derived hormones, as risk factors or potential treatments for ischemic stroke. In addition, the potential for relaxin, a lesser studied sex hormone, as a novel treatment option for ischemic stroke is explored.

Adipokines in neurovascular diseases

Adipose tissue is now described as an endocrine organ secreting a number of adipokines contributing to the development of inflammation and metabolic imbalance, but also endothelial dysfunction, vascular remodeling, atherosclerosis, and ischemic stroke. Leptin, adiponectin, and resistin are the most studied adipokines which play important roles in the regulation of cardiovascular homeostasis. Leptin and adiponectin mediate both proatherogenic and antiatherogenic responses. Leptin and adiponectin have been linked to the development of coronary heart disease and may be involved in the underlying biological mechanism of ischemic stroke. Resistin, a pro-inflammatory cytokine, is predictive of atherosclerosis and poor clinical outcomes in patients with coronary artery disease and ischemic stroke. The changes in serum levels of novel adipokines apelin, visfatin are also associated with acute ischemic stroke. These adipokines have been proposed as potential prognostic biomarkers of cardiovascular mortality/morbidity and therapeutic targets in patients with cardiometabolic diseases. In this article, we summarize the biologic role of the adipokines and discuss the link between dysfunctional adipose tissue and metabolic/inflammation imbalance, consequently endothelial damage, progression of atherosclerotic disease, and the occurrence of ischemic stroke.

Leptin and adiponectin: pathophysiological role and possible therapeutic target of inflammation in ischemic stroke

Stroke is a multifactorial disease contributing to significant noncommunicable disease burden in developing countries. Risk of stroke is largely a consequence of morbidities of diabetes, obesity, hypertension, and heart diseases. Incidence of stroke is directly proportional to body mass index. Adipose tissue stores energy as well as acts as an active endocrine organ, which secretes numerous humoral factors. Adiponectin and leptin are the commonest adipocytokines and have been invariably linked to the development of coronary heart disease and may be involved in the underlying biological mechanism of stroke. Leptin and adiponectin mediate proatherogenic and antiatherogenic responses, respectively, and hence, determining the plasma or serum levels of leptin and adiponectin alone or in combination may act as a novel prognostic biomarker for inflammation and atherosclerosis in stroke. This review addresses leptin- and adiponectin-mediated inflammatory mechanism in ischemic stroke and their potential as therapeutic targets.

Cerebrovascular Disease: Consequences of Obesity-Induced Endothelial Dysfunction

Despite the well-known global impact of overweight and obesity in the incidence of cerebrovascular disease, many aspects of this association are still inconsistently defined. In this chapter we aim to present a critical review on the links between obesity and both ischemic and hemorrhagic stroke and discuss its influence on functional outcomes, survival, and current treatments to acute and chronic stroke. The role of cerebrovascular endothelial function and respective modulation is also described as well as its laboratory and clinical assessment. In this context, the major contributing mechanisms underlying obesity-induced cerebral endothelial function (adipokine secretion, insulin resistance, inflammation, and hypertension) are discussed. A special emphasis is given to the participation of adipokines in the pathophysiology of stroke, namely adiponectin, leptin, resistin, apelin, and visfatin.

Association of Adiponectin Polymorphism with Metabolic Syndrome Risk and Adiponectin Level with Stroke Risk: A Meta-Analysis

Many previous studies have provided evidence that the ADIPOQ +45T>G polymorphism (rs2241766) might cause metabolic syndrome (MS). As a cardiovascular manifestation of MS, the incidence of stroke is associated with adiponectin; however, the results remain controversial and inconsistent. Systematic searches of relevant studies published up to Dec 2014 and Jan 2016 on the ADIPOQ +45T>G polymorphism and the risk of MS and adiponectin levels and the risk of stroke, respectively, were conducted in MEDLINE and EMBASE. The odds ratio (OR) or risk ratio (RR) and their 95% confidence interval (95% CI) were extracted. Sixteen studies containing 4,113 MS cases and 3,637 healthy controls indicated a weak positive association between ADIPOQ +45 T>G and MS in the dominant genetic model (OR = 1.30, 95% CI = 1.03-1.65), which was also validated by stratified subgroup analyses. Twelve studies including 26,213 participants and 4,246 stroke cases indicated that 5 μg/ml increments in adiponectin level were not relevant to stroke risk (RR = 1.05, 95% CI = 1.00-1.10, P = 0.069). This study suggested a weak positive association of ADIPOQ +45T>G with MS and a strong association with metabolic-related disease. Additionally, adiponectin level was not a causal factor of increasing stroke risk.

The Abundance of Epicardial Adipose Tissue Surrounding Left Atrium Is Associated With the Occurrence of Stroke in Patients With Atrial Fibrillation

Epicardial adipose tissue (EAT) is positively associated with risk factors for cardiovascular disease, but the role of EAT in the development of atrial fibrillation (AF)-related stroke and its association with the anatomical and functional remodeling of the left atrium (LA) have not been elucidated.This was a comparative cross-sectional study. Twenty-seven patients with paroxysmal or persistent AF and cardioembolic stroke were selected and compared with 68 age- and sex-matched AF patients without stroke. In addition, 20 controls without a history of AF or stroke were included. The periatrial EAT and the structural and functional properties of the LA and left ventricle were evaluated using contrast-enhanced 64-slice multidetector computed tomography during sinus rhythm. Total EAT around the LA was significantly increased across the groups (control vs AF vs AF-related stroke, P < 0.001). The volumes of the LA and the LA appendage (LAA) were also significantly increased across the 3 groups (P < 0.001 for each). The emptying fraction of the LA and LAA and the booster-pump function of the LA and LAA were all reduced across the 3 groups (P < 0.001 for all). In addition, the Hounsfield unit (HU) ratio of the LAA to the ascending aorta (LAA/AA) was also decreased in patients with stroke (P < 0.001). Furthermore, EAT had a negative correlation with the dynamic function of the LA, LAA, and the HU ratio. After a multivariate analysis, increased EAT (P < 0.001) was shown to be independently associated with the occurrence of AF-related stroke.Periatrial EAT was increased and was correlated with atrial dysfunction in patients with AF-related stroke. Hence, EAT assessment may potentially offer an incremental value for grading the risk of cardioembolic stroke in patients with AF.

The role of adipokines in ischemic stroke risk stratification

Background

Adiponectin, leptin, and resistin are the most well-studied adipokines and play important roles in the regulation of glucose metabolism, subclinical inflammation, and cardiovascular homeostasis. Accordingly, measurement of adipokine levels might be useful in cardiovascular risk stratification. Moreover, the study of single-nucleotide polymorphisms of genes that encode these adipokines might also represent a valuable predictive tool in cardiovascular disease prevention strategies.

Aims

To summarize the biologic role of the adipokines adiponectin, leptin, and resistin and the prognostic value of their serum levels regarding the occurrence and outcome of ischemic stroke. We also discuss the relationship of single-nucleotide polymorphisms of the adiponectin, leptin genes, and the −420C > G polymorphism of resistin gene with stroke risk.

Summary of review

Several studies in the general population evaluated the association between these adipokines and stroke risk, yielding conflicting results. There are more limited data regarding the effect of these adipokines on stroke severity and outcome. A small number of studies also assessed the predictive role of single-nucleotide polymorphisms of the adiponectin, leptin, and resistin genes regarding stroke risk, but the findings were also controversial.

Conclusions

It is unclear whether adiponectin, leptin, and resistin levels or the single-nucleotide polymorphisms of their encoding genes are independently associated with stroke risk. However, given the role of these adipokines in the pathogenesis of atherosclerosis, larger prospective studies, both in the general population and in patients with a history of stroke, are needed to determine whether the measurement of serum levels of these adipokines or the evaluation of single-nucleotide polymorphisms in their encoding genes could improve stroke risk prediction. If this relationship is proven, therapeutic interventions targeting adipokine levels might represent a novel approach to reduce stroke-related mortality and disability.

Serum Leptin Levels and the Risk of Stroke: The Framingham Study

BACKGROUND AND PURPOSE

Leptin is a major adipokine that regulates weight balance and energy homeostasis. There is inconsistent evidence linking circulating leptin levels to risk of stroke. We tested the hypothesis that leptin levels are associated with risk of incident stroke in an elderly community based sample.

METHODS

Serum leptin levels were assayed in 757 stroke free individuals (mean age, 79 years; 62% women) from the Framingham Original Cohort at the 22nd examination cycle (1990-1994). Incidence of all -stroke and ischemic stroke were prospectively ascertained.

RESULTS

During a mean follow up of 10 years, 119 individuals developed stroke (99 ischemic strokes). In multivariable Cox regression models, log leptin levels were not associated with incidence of all -stroke or ischemic stroke (hazard ratios per SD increment in log leptin 0.90 [0.73-1.09] and 0.89 [0.72-1.11], respectively). The results were suggestive for potential effect modification by waist/hip ratio for the association between leptin and stroke (P=0.03). Adjusting for age, sex, and established stroke risk factors, analysis stratified by waist/hip ratio quartiles revealed a lower incidence of first-ever all-stroke and ischemic stroke associated with higher leptin levels among only subjects in the top waist/hip ratio quartile (hazard ratio, 0.64 [0.43, 0.95] versus 0.98 [0.77, 1.25] for incident all-stroke and 0.61 [0.39, 0.95] versus 0.96 [0.74, 1.26] for ischemic stroke).

CONCLUSIONS

Leptin levels were not directly related to the risk of incident stroke overall but there was an inverse association with stroke in the top waist/hip ratio quartile. Further investigations are required to confirm these findings and explore possible mechanisms for the observed association.

The Intricate Network of Adipokines and Stroke

Cerebrovascular disorders, particularly ischemic stroke, are one of the most common neurological disorders. High rates of overweight and obesity support an interest in the role of adipose tissue and adipose tissue releasing cytokines in inducing associated comorbidities. Adipokines can serve as a key messenger to central energy homeostasis and metabolic homeostasis. They can contribute to the crosstalk between adipose tissue and brain. However recent research has offered ambiguous data on the network of adipose tissue, adipokines, and vascular disorders. In our paper we provide a critical insight into the role of adipokines in evolution of ischemic stroke.

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.

Gender differences in adiponectin levels and body composition in older adults: Hallym aging study

Background

Body composition changes with ageing can influence the adiponectin concentration. However, the component of body composition that is associated with adiponectin concentrations in older adults remains unclear.

Methods

There were 152 males and 168 females aged 65 years or older that participated in the 2010 Hallym Aging Study (HAS). Body composition (assessed by dual energy X-ray absorptiometry; DXA), anthropometric parameters and adiponectin were obtained from all participants. Multivariate linear regression models assessed the association of body fat percentage, regional muscle and bone mineral contents of body composition and waist/height ratio with adiponectin concentration. Age, albumin, testosterone concentration and metabolic parameters were considered as confounding factors.

Results

In correlation analysis, age was positively associated with adiponectin in males (P < 0.01), but not in females. Fasting glucose, albumin, arm skeletal muscle mass and bone mineral content were negatively associated with adiponectin in males (P < 0.05). Testosterone and leg bone mineral content were negatively associated with adiponectin in females (P < 0.05). In multivariate linear regression models, body fat percentage and albumin (P < 0.05) were negatively associated with adiponectin, and high-density lipoprotein cholesterol (HDL-C) (P < 0.001) and age (P < 0.01) were positively associated with adiponectin in older males. In older females, the only factors that correlated significantly with adiponectin concentration were the homeostasis model assessment of insulin resistance (P < 0.001) and HDL-C (P < 0.05). The waist/height ratio and bone mineral content were not associated with adiponectin in either gender.

Conclusion

Plasma adiponectin levels correlated negatively with body fat percentage in older males but not in older females. The differential results between older males and females suggest that certain gender-specific mechanisms may affect the association between adiponectin and age-related body composition changes.

Adiponectin and risk of stroke: prospective study and meta-analysis

BACKGROUND AND PURPOSE

The favorable cardiovascular effects attributed to adiponectin may lower risk of stroke. We investigated this in a prospective study and meta-analysis.

METHODS

A case-cohort study nested within the Potsdam cohort of the European Prospective Investigation into Cancer was performed, with 170 incident cases of ischemic stroke and a randomly selected subcohort of 2155 participants without major cardiovascular disease at baseline. A random-effects dose-response meta-analysis was performed on prospective studies reporting on adiponectin and incident stroke in healthy populations up to April 2013, identified through MEDLINE and EMBASE.

RESULTS

In European Prospective Investigation into Cancer-Potsdam, after adjustment for cardiovascular risk factors, the hazard ratio of ischemic stroke per 5-µg/mL higher total-adiponectin was 1.10 (95% confidence interval, 0.89-1.37). Participants with higher total-adiponectin had higher high-density lipoprotein-cholesterol and lower high-sensitivity C-reactive protein and triglyceride levels, and had less often diabetes mellitus. Additional adjustment for these putative mediators yielded a hazard ratio of 1.31 (95% confidence interval, 1.04-1.64). Nine studies (19,259 participants, 2960 cases), including European Prospective Investigation into Cancer-Potsdam, were meta-analyzed. Pooling relative risks adjusted for cardiovascular risk factors not including putative mediators indicated moderate between-study heterogeneity (I2=52.2%). This was explained by the smallest study, and the pooled relative risk (95% confidence interval) before and after its exclusion was 1.03 (0.98-1.08) and 0.99 (0.96-1.01) per 5 µg/mL, respectively. The pooled relative risk (95% confidence interval) additionally adjusted for potential mediators was 1.08 (1.01-1.15) and 1.05 (1.00-1.11) before and after excluding the same study, respectively.

CONCLUSIONS

Adiponectin is not associated with risk of stroke. If anything, adiponectin relates directly to stroke risk after controlling for risk factors that favorably correlate with adiponectin.

Is a child's growth pattern early in life related to serum adipokines at the age of 10 years?

BACKGROUND/OBJECTIVES

Growth parameters during infancy and early childhood might predict adipokine levels later in life. This study investigates the association between peak growth velocities, body mass index (BMI) and age at adiposity rebound (AR), with leptin and adiponectin levels at age 10 years.

SUBJECTS/METHODS

Peak height (PHV) and weight (PWV) velocities were calculated from height and weight measurements obtained between birth and age 2 years from 2880 children participating in the GINIplus (German Infant Nutritional Intervention plus environmental and genetic influences on allergy development) and LISAplus (Influences of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood plus Air Pollution and Genetics) birth cohorts. BMI and age at AR were calculated using BMI measurements between age 1.5 and 12 years. Blood samples were collected during a physical examination at age 10. Adiponectin and leptin levels were measured by radioimmunoassay. Linear regression models were fitted after adjustment for potential confounding factors and results are presented per interquartile range increase in the exposure.

RESULTS

Age at AR was negatively associated with leptin in males and females (percent difference β*: -41.71%; 95% confidence interval: (-44.34;-38.96) and β*: -43.22%; (-45.59; -40.75), respectively). For both males and females PWV (β*: 14.23%; (7.60; 21.26) and β*: 18.54%; (10.76; 26.87), respectively) and BMI at AR (β*: 63.08%; (55.04; 71.53) and β*: 67.02%; (59.30; 75.10), respectively) were positively associated with leptin levels. PHV showed a positive effect on leptin in females only (β*: 10.75%; (3.73; 18.25)). Growth parameters were not significantly associated with adiponectin except for age at AR among females (β: 0.75 ng/ml; (0.42; 1.09)) and PWV among males (β: 0.45 ng/ml; (0.11; 0.79)).

CONCLUSION

Growth patterns in early life may be associated with leptin levels at age 10 years.