Contribution of obesity as an effect regulator to an association between serum leptin and incident metabolic syndrome

Association of serum leptin and insulin levels among type 2 diabetes mellitus patients: A case-control study

Secretion of insulin is compromised in type 2 diabetes (T2DM) individuals and inadequate to accommodate for insulin resistance (IR) in peripheral tissue. Hyperleptinemia reflects leptin resistance, which is a key factor in the production of IR in T2DM patients, making leptin a potential biomarker for evaluating IR levels. The objective of the study was to assess the association of serum leptin and insulin levels among T2DM patients. This case-control research was carried out on T2DM patients. A total of 73 patients diagnosed with T2DM (the case group) and 40 healthy participants (control; group 3) were enrolled according to the American Diabetes Association (ADA) criteria. In the case group, T2DM patients were enrolled with metabolic syndrome (group 1, n = 38) or without metabolic syndrome (group 2, n = 35) according to the WHO criteria. Metabolic profiles of T2DM patients with or without metabolic syndrome were evaluated, and compare these two groups with healthy controls. The subjects of all groups were age- and gender-matched. Body mass index (BMI, P < .01), fasting (P = .0133) and postprandial (P < .01) blood sugar levels, % glycated hemoglobin (HbA1c, P < .01), and lipid profile (P < .01) were found significantly different and higher in group 1 as compared to groups 2 and 3. Serum leptin and insulin levels were found higher and significant in patients with metabolic syndrome (P < .01 for both). The values of serum leptin levels were 10.01 ± 2.7 ng/mL, 6.9 ± 2.4 ng/mL, and 4.11 ± 1.8 ng/mL, and those of serum insulin 120 ± 40.7 µIU/mL, 20.43 ± 5.2 µIU/mL, and 11.4 ± 2.5 µIU/mL in groups 1, 2, and 3, respectively. There was a positive linear correlation between BMI, blood sugar, HbA1c, serum cholesterol (TC), and triglycerides (TG) with serum insulin and leptin levels in the case group. An extremely significant correlation (R = 0.74, P < .001) was found in BMI and serum leptin level in the case group. Serum leptin and insulin levels have a positive association, with serum leptin being a significant predictor of IR syndrome (Evidence Level: 5; Technical Efficacy: Stage 3).

Association between lifestyle factors and metabolic syndrome in general populations with depressive symptoms in cross-setional based cohort study of Ansung-Ansan

Background

Metabolic syndrome (MetS) is caused by both genetic and environmental factors, such as daily calorie intake, smoking, and alcohol consumption. Lifestyle factors, such as alcohol consumption, are considered to be related to the prevalence of MetS and plays an essential role in the pathogenesis and prognosis of depression.

Methods

We investigated the bidirectional association between lifestyle factors and MetS among Korean adults with depressive symptoms in third wave of a community-based cohort study. A total of 1,578 individuals, aged 39–72 years, who had MetS at baseline were recruited. Participants were divided into two groups according to depressive symptoms. Logistic regression models were used to estimate the risk of MetS.

Results

The percentage of heavy drinkers was lower in men with depressive symptoms compared to those who did not (7.0% vs. 7.1%), while the percentage of current smokers were higher in participants who had depressive symptoms (40.2% vs. 30.0%). After adjusting for age, education, monthly income, body mass index (BMI), sleep duration, and volume of drinking and smoking status, logistic regression analysis demonstrated that male heavy drinkers with depressive symptoms were 2.75 times more likely to have MetS than those without depressive symptom. Conversely, depressive women with a high BMI were 3.70 times more likely to have MetS than in those with lower BMI. Limitations The cross-sectional nature of the study, and the study population ethnicity and ages were limitations.

Conclusions

Lifestyle factors, such as alcohol consumption, may be associated with the risk of MetS in adults with depressive symptoms.

Exercise training modulates adipokines dysregulations in metabolic syndrome

Metabolic syndrome (MetS) is a cluster of risk factors for various metabolic diseases, and it is characterized by central obesity, dyslipidemia, hypertension, and insulin resistance. The core component for MetS is adipose tissue, which releases adipokines and influences physical health. Adipokines consist of pro and anti-inflammatory cytokines and contribute to various physiological functions. Generally, a sedentary lifestyle promotes fat accumulation and secretion of pro-inflammatory adipokines. However, regular exercise has been known to exert various beneficial effects on metabolic and cognitive disorders. Although the mechanisms underlying exercise beneficial effects in MetS are not fully understood, changes in energy expenditure, fat accumulation, circulatory level of myokines, and adipokines might be involved. This review article focuses on some of the selected adipokines in MetS, and their responses to exercise training considering possible mechanisms.

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Adipokines are a potential link between visceral fats and complications of MetS.

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Physical inactivity increases pro-inflammatory adipokines.

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Moderate aerobic exercise increases anti-inflammatory adipokines partly via reducing adipose tissue mass.

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Physical exercise-induced myokines might mediate beneficial effects via a cross-talk with adipose tissues.

Can biomarkers be used to improve diagnosis and prediction of metabolic syndrome in childhood cancer survivors? A systematic review

Childhood cancer survivors (CCS) are at increased risk to develop metabolic syndrome (MetS), diabetes, and cardiovascular disease. Common criteria underestimate adiposity and possibly underdiagnose MetS, particularly after abdominal radiotherapy. A systematic literature review and meta-analysis on the diagnostic and predictive value of nine newer MetS related biomarkers (adiponectin, leptin, uric acid, hsCRP, TNF-alpha, IL-1, IL-6, apolipoprotein B (apoB), and lipoprotein(a) [lp(a)]) in survivors and adult non-cancer survivors was performed by searching PubMed and Embase. Evidence was summarized with GRADE after risk of bias evaluation (QUADAS-2/QUIPS). Eligible studies on promising biomarkers were pooled. We identified 175 general population and five CCS studies. In the general population, valuable predictive biomarkers are uric acid, adiponectin, hsCRP and apoB (high level of evidence), and leptin (moderate level of evidence). Valuable diagnostic biomarkers are hsCRP, adiponectin, uric acid, and leptin (low, low, moderate, and high level of evidence, respectively). Meta-analysis showed OR for hyperuricemia of 2.94 (age-/sex-adjusted), OR per unit uric acid increase of 1.086 (unadjusted), and AUC for hsCRP of 0.71 (unadjusted). Uric acid, adiponectin, hsCRP, leptin, and apoB can be alternative biomarkers in the screening setting for MetS in survivors, to enhance early identification of those at high risk of subsequent complications.

A novel and disposable GP- based impedimetric biosensor using electropolymerization process with PGA for highly sensitive determination of leptin: Early diagnosis of childhood obesity

This study presents a novel, single-use electrochemical biosensor for the leptin biomarker, which may have potential use for early diagnosis of childhood obesity. The graphite paper working electrode was used for the first time in impedimetric biosensors. All immobilization procedure, investigation of the optimal parameters and characterization of biosensors were followed and evaluated using Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). The Scanning Electron Microscope (SEM) was utilized to visualize the morphology of the electrode surface during the immobilization steps of the immunosensor. Moreover, the characterization of the interactions between anti-leptin and leptin was investigated by using Single Frequency Technique (SFI). The applicability of the designed biosensor for real serum samples was tested for clinical use. It was observed that the biosensor allows high sensitivity in the analyte detection (leptin) in real serum samples. Moreover, it was suggested that the developed biosensor presents advantages such as long shelf life (5% loss of activity after 8 weeks and 60% loss after 10 weeks), ability to determine analyte concentrations at picogram level (0.2 pg mL^-1 -20 pg mL^-1), low limit of detection (0.00813 pg mL^{- 1}), reproducibility, reusability (12 times) and high sensitivity.

The Incidence of Metabolic Syndrome and the Valid Blood Pressure Cutoff Value for Predicting Metabolic Syndrome Within the Normal Blood Pressure Range in the Population Over 40 Years Old in Guiyang, China

PURPOSE

The study was conducted to investigate metabolic syndrome (MS) incidence within the normal blood pressure (BP) range in a population over 40 years old in an urban area of Guiyang, Guizhou Province, China, and to identify a valid BP cutoff value for predicting MS.

MATERIALS AND METHODS

Data from this study are based on the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study. In total, 2935 subjects in the normal BP range and without MS (795 males, 2140 females) aged 40-80 years were included in this study. Follow-up subjects were classified by baseline BP and grouped by age. After the 3-year follow-up, the MS incidence and valid BP cutoff value for predicting MS were calculated for subjects within the normal BP range.

RESULTS

After the 3-year follow-up study, the crude and standardized MS incidences in the cohort were 19.83% and 16.89% for follow-up subjects, respectively, with incidences of 10.94% and 10.50% for males and 23.13% and 20.66% for females. The incidence of MS in normotensive subjects (15.53%) was lower than that in subjects with high-normal BP (29.08%). After adjusting for age, sex, BMI, smoking, and drinking, the risk of having MS in the high-normal BP group was 1.823-fold [HR 1.823 95% CI (1.538-2.162)] higher than that in the normotensive group. The ROC curve showed that the BP cutoff values were more than 117/74 mmHg in males and 112/74 mmHg in females.

CONCLUSION

When BP was within the normal range, the incidence of MS in participants was very high. The MS incidence was higher among high-normal BP subjects than among normotensive subjects, as was the risk of having MS. The valid BP cutoff value for predicting MS in the population was 117/74 mmHg in males and 112/74 mmHg in females. Currently, epidemiological investigations are needed to determine whether a lower BP cutoff value is needed in diagnosing MS.

Genetically, Dietary Sodium Intake Is Causally Associated with Salt-Sensitive Hypertension Risk in a Community-Based Cohort Study: a Mendelian Randomization Approach

PURPOSE OF REVIEW

Excessive dietary salt intake is associated with an increased risk of hypertension. Salt sensitivity, i.e., an elevation in blood pressure in response to high dietary salt intake, has been associated with a high risk of cardiovascular disease and mortality. We investigated whether a causal association exists between dietary sodium intake and hypertension risk using Mendelian randomization (MR).

RECENT FINDINGS

We performed an MR study using data from a large genome-wide association study comprising 15,034 Korean adults in a community-based cohort study. A total of 1282 candidate single nucleotide polymorphisms associated with dietary sodium intake, such as rs2960306, rs4343, and rs1937671, were selected as instrumental variables. The inverse variance weighted method was used to assess the evidence for causality. Higher dietary sodium intake was associated with salt-sensitive hypertension risk. The variants of SLC8E1 rs2241543 and ADD1 rs16843589 were strongly associated with increased blood pressure. In the logistic regression model, after adjusting for age, gender, smoking, drinking, exercise, and body mass index, the GRK4 rs2960306TT genotype was inversely associated with hypertension risk (OR, 0.356; 95% CI, 0.236-0.476). However, the 2350GG genotype (ACE rs4343) exhibited a 2.11-fold increased hypertension risk (OR, 2.114; 95% CI, 2.004-2.224) relative to carriers of the 2350AA genotype, after adjusting for confounders. MR analysis revealed that the odds ratio for hypertension per 1 mg/day increment of dietary sodium intake was 2.24 in participants with the PRKG1 rs12414562 AA genotype. Our findings suggest that dietary sodium intake may be causally associated with hypertension risk.

Association between serotonin 2A receptor (HTR2A) genetic variations and risk of hypertension in a community-based cohort study

Background

Hypertension is one of the risk factors for obesity-related cardiovascular diseases. We investigated whether genetic variations in serotonin 2A receptor (HTR2A) were associated with hypertension.

Methods

We carried out a cross-sectional study in cohorts A (Ansan-Ansung cohort, N = 6039) and B (Wonju-Pyengchang cohort, N = 7524). Several genetic variants in HTR2A including rs7330636, rs9590999, rs2183057, and rs4942595 were selected and genotyped.

Results

In hypertensive participants in cohort A, the baseline systolic blood pressure and body mass index were 141.80 ± 17.20 mg/dL and 24.48 ± 4.75 kg/m², respectively, which were higher than in those without hypertension (p < 0.001). rs4942595TC genotype was associated with hypertension in cohort A (OR = 0.739), after adjusting for variables. Subjects with rs4942578AA genotype had a decreased risk of hypertension after adjusting for clinical factor (OR = 0.735) in cohort B, and an elevated risk of hypertension in cohort A (OR = 1.562). The logistic regression analysis showed that participants with rs4941573TC genotype were 1.327 times more likely to have a higher blood pressure than those with TT genotype (95% CI 1.101–1.599) in cohort B. Whereas, the OR for developing hypertension in subjects with rs17069883CC genotype compared to those with AA genotype was 1.447 (95% CI 1.018–2.056; p for trend = 0.040) in cohort A.

Conclusions

HTR2A genetic variations were associated with hypertension risk in our study.

Anti-obesity effects of instant fermented teas in vitro and in mice with high-fat-diet-induced obesity

Obesity is a chronic metabolic disorder that is associated with higher risks of developing diabetes and cardiovascular disease. Chinese dark tea is a fermented beverage with many biological effects and could be considered for the management of obesity. This study is aimed to assess the possible anti-obesity properties of instant dark tea (IDT) and instant pu-erh tea (PET) in high fat diet (HFD)-fed mice. Male C57BL/6 mice were divided into 5 groups. They received low-fat diet (LFD), HFD, HFD supplemented with drinking IDT infusion (5 mg mL-1), PET infusion (5 mg mL-1) or water for 8 weeks. The results showed IDT exhibited better inhibitory effect than PET on body weight gain and visceral fat weights. IDT also improved the serum high-density lipoprotein cholesterol (HDL-C) level, but decreased the low-density lipoprotein cholesterol (LDL-C) and leptin levels more effectively than PET. Both IDT and PET lowered the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the plasma and significantly increased the ratio of albumin to globin (A/G) in the serum compared to the control group. IDT treatment reduced the malondialdehyde (MDA) level in the liver. Histomorphology evidenced that the liver tissue architecture was well preserved by IDT administration. Moreover, IDT regulated the expression of obesity-related genes more effectively than PET. Overall, the present findings have provided the proof of concept that dietary IDT could provide a safer and cost-effective option for people with HFD-induced obesity.