Effect of increased leptin and C-reactive protein levels on mortality: results from the National Health and Nutrition Examination Survey

Associations Between High-Sensitivity C-Reactive Protein and All-Cause Mortality Among Oldest-Old in Chinese Longevity Areas: A Community-Based Cohort Study

Background

The association between high-sensitivity C-reactive protein (hsCRP) levels and all-cause mortality for the oldest-old (aged 80 years or older) remains unclear. We aimed to investigate the associations between hsCRP concentrations and the risks of all-cause mortality, and further identify the potential modifying factors affecting these associations among the oldest-old.

Methods

This prospective, community-based cohort study included 2,206 participants aged 80 years or older (median age 93.0 years) from the Healthy Aging and Biomarkers Cohort Study. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) with 95% confidential intervals (95% CIs) for all-cause mortality according to hsCRP quartiles and recommendation for relative risk categories of hsCRP levels (< 1.0, 1.0–3.0, and > 3.0 mg/L), with adjustment for sociodemographic information, lifestyle, physical examination, medical history, and other potential confounders.

Results

During a median follow-up period of 3.1 years (IQR: 1.6–3.9 years), 1,106 deaths were verified. After full adjustment for potential confounders, a higher hsCRP concentration was positively associated with an increased risk of all-cause mortality (P for trend < 0.001). Compared with the lowest quartile, the fully adjusted HRs of the second, third, and fourth quartiles were 1.17 (95% CI: 0.94, 1.46), 1.28 (95% CI: 1.01, 1.61), and 1.49 (95% CI: 1.20, 1.87), respectively. The association of hsCRP with all-cause mortality was modified by smoking status (P for interaction = 0.011), an increased risk of hsCRP with all-cause mortality showed among non-current smokers (HR: 1.17; 95% CI: 1.07, 1.28), but no significance was observed in current smokers (HR: 0.83; 95% CI: 0.66, 1.18).

Conclusions

Our study indicated that elevated hsCRP concentrations were associated with a higher risk of all-cause mortality among Chinese oldest-old. Future studies investigating additional factors of disease and aging processes are needed to obtain a better understanding of the mechanisms.

Leptin and advanced glycation end products receptor (RAGE) in tuberculosis patients

Introduction

The pathogenesis of consumptive syndrome of tuberculosis (TB) is largely unknown. Leptin concentrations may be high because of the host’s inflammatory response, contributing to weight loss in patients with TB. The receptor for advanced glycation end products (RAGE) is also associated with weight loss in patients with TB and is related to enhanced mortality. The objective of this study was to evaluate the association between leptin and AGE/RAGE.

Methods

Case-control study. Leptin, AGE (carboxymethyl lysine, CML) and soluble RAGE (sRAGE) were measured from blood samples by ELISA.

Results

We included in the study 34 patients with TB and 34 controls. We found an inverse correlation between serum leptin levels and sRAGE, only in cases (r = -0.609, p < 0.0001). sRAGE levels were lower in patients with TB who died as compared with patients who survive (21.90 ± 4.24 pg/mL vs 66.14 ± 29.49 pg/mL; p = 0.045). Leptin levels were higher in patients with TB who died as compared with patients who survive (14.11 [7.48–14.11] ng/mL vs 3.08 [0.54–6.34] ng/mL; p = 0.028).

Conclusions

We identified lower sRAGE levels and higher leptin levels in patients with TB who died as compared with patients who survive. In addition, an inverse and significant correlation between serum leptin and sRAGE levels was demonstrated. Future studies, with a larger sample size and in different settings, including not only hospitalized patients, are needed to confirm these findings.

Serum Leptin in Hospitalized Community-Acquired Pneumonia Children under the Age of Five Years

Background

Community-acquired pneumonia (CAP) accounts for 19% of the world’s total deaths among all age groups yearly, with highest rates in children less than 5 years. This study is designed to evaluate the serum leptin level in hospitalized children under the age of 5 years with CAP.

Results

This prospective cross-sectional study included CAP children under the age of 5 years. Forty-one patients admitted to pediatric intensive care unit (PICU) and 41 patients admitted to general ward were enrolled. Patients with any other cause that may elevate serum leptin were excluded. Serum leptin was measured on the day of admission. The PICU patients had a significantly higher median serum leptin than that of the ward patients (p < 0.001). C-reactive protein (CRP) level was significantly higher in patients with elevated serum leptin than in patients with normal serum leptin (p = 0.001). There was a significant association between high serum leptin and positive sputum cultures (p < 0.001), particularly cultures growing more than one organism (p < 0.001). There was a positive, weak correlation between serum leptin and length of stay (r = 0.30, p = 0.007). Serum leptin showed good discrimination between PICU admissions and inpatient ward admissions (AUC = 0.777, p < 0.001); at a cut-off value of > 29.6 pg/ml, serum leptin had a sensitivity of 70.7% and a specificity of 87.8%

Conclusion

We may conclude that CAP patients with a serum leptin level above 29.6 pg/ml should be considered for PICU admission.

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.

Translating the biology of adipokines in atherosclerosis and cardiovascular diseases: Gaps and open questions

AIM

Critically discuss the available data, to identify the current gaps and to provide key concepts that will help clinicians in translating the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

DATA SYNTHESIS

Adipose tissue is nowadays recognized as an active endocrine organ, a function related to the ability to secrete adipokines (such as leptin and adiponectin) and pro-inflammatory cytokines (tumor necrosis factor alpha and resistin). Studies in vitro and in animal models have observed that obesity status presents a chronic low-grade inflammation as the consequence of the immune cells infiltrating the adipose tissue as well as adipocytes. This inflammatory signature is often related to the presence of cardiovascular diseases, including atherosclerosis and thrombosis. These links are less clear in humans, where the role of adipokines as prognostic marker and/or player in cardiovascular diseases is not as clear as that observed in experimental models. Moreover, plasma adipokine levels might reflect a condition of adipokine-resistance in which adipokine redundancy occurs. The investigation of the cardio-metabolic phenotype of carriers of single nucleotide polymorphisms affecting the levels or function of a specific adipokine might help determine their relevance in humans. Thus, the aim of the present review is to critically discuss the available data, identify the current gaps and provide key concepts that will help clinicians translate the biology of adipokines in the context of atherosclerosis and cardio-metabolic diseases.

Adiponectin, leptin, nitric oxide, and C-reactive protein levels in kidney transplant recipients: comparison with the hemodialysis and chronic renal failure

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in patients with chronic kidney disease (CKD) including kidney transplant recipients (KTR). Secondary lipid metabolism disorders, endothelial dysfunction, and inflammation enhance the risk of CVD development in these patients. The aim of the present study was to investigate the lipid profile, adiponectin, leptin, nitric oxide (NO), and high sensitivity C-reactive protein (hs-CRP) levels in KTR and to compare these parameters with those of the patients with chronic renal failure (CRF), hemodialysis (HD) patients, and healthy controls.

METHODS

Serum adiponectin and leptin levels were measured by radioimmunoassay; hs-CRP was determined immunoturbidimetrically. Determination of NO was based on the Griess reaction.

RESULTS

Compared with the control group, serum NO and adiponectin levels were significantly higher in the KTR, CRF, and HD groups; hs-CRP levels were significantly higher in the KTR and HD groups; leptin levels were significantly higher in the KTR. In addition, serum NO level was significantly higher in the KTR compared to CRF cases. Adiponectin correlated positively with high density lipoprotein-cholesterol in the control and patient groups. A positive correlation was observed between hs-CRP and NO in the KTR and the patients with CRF. Serum adiponectin levels were inversely correlated with hs-CRP and leptin in the HD group.

CONCLUSION

KTR suffer from inflammation and accompanying changes in levels of adipocytokines and NO which contribute to the increased risk of CVD in these patients.

Serum leptin, C-reactive protein, and cancer mortality in the NHANES III

Adipokines, such as leptin, may affect cancer through its link with inflammation and obesity. We investigated the association between leptin, C‐reactive protein, and risk of cancer death while accounting general and abdominal obesity. From the Third National Health and Examination Survey (NHANES III), we selected 5957 adult men and women with baseline measurements of serum leptin and CRP. Multivariable Cox regression was used to assess leptin and CRP levels (low, moderate, high) in relation to risk of cancer death. Stratification analyses were performed for obesity as defined by body mass index (BMI) and waist circumference. Fine and Gray regression was performed to account for death from cardiovascular disease and other causes as competing events. A total of 385 participants died of cancer during a mean follow‐up of 18 years. After adjusting for BMI and waist circumference, an inverse association with log‐transformed leptin was found for women, with a hazard ratio (HR) of 0.81 (95% confidence interval [CI]: 0.51–1.30) and 0.40 (95% CI: 0.24–0.68) for moderate and high compared to low levels of leptin, respectively; P_trend = 0.0007). No association for leptin was observed in men, but higher CRP corresponded to increased risk of dying from cancer (HR: 2.98; 95% CI: 1.57–5.64 for the highest vs. lowest categories of CRP). Similar associations were observed with competing risk analysis also adjusted for BMI and waist circumference. Contrasting associations of serum leptin and CRP with cancer mortality may indicate sex‐specific biological or environmental pathways linking obesity and cancer in men and women which warrant mechanistic investigations.