Relationship of leptin level with metabolic disorders and hypertension in Japanese type 2 diabetes mellitus patients

Unlocking the Benefits of Fasting: A Review of its Impact on Various Biological Systems and Human Health

Fasting has gained significant attention in recent years for its potential health benefits in various body systems. This review aims to comprehensively examine the effects of fasting on human health, specifically focusing on its impact on different body's physiological systems. The cardiovascular system plays a vital role in maintaining overall health, and fasting has shown promising effects in improving cardiovascular health markers such as blood pressure, cholesterol levels, and triglyceride levels. Additionally, fasting has been suggested to enhance insulin sensitivity, promote weight loss, and improve metabolic health, thus offering potential benefits to individuals with diabetes and metabolic disorders. Furthermore, fasting can boost immune function, reduce inflammation, enhance autophagy, and support the body's defense against infections, cancer, and autoimmune diseases. Fasting has also demonstrated a positive effect on the brain and nervous system. It has been associated with neuroprotective properties, improving cognitive function, and reducing the risk of neurodegenerative diseases, besides the ability of increasing the lifespan. Hence, understanding the potential advantages of fasting can provide valuable insights for individuals and healthcare professionals alike in promoting health and wellbeing. The data presented here may have significant implications for the development of therapeutic approaches and interventions using fasting as a potential preventive and therapeutic strategy.

New Insights into Adiponectin and Leptin Roles in Chronic Kidney Disease

Chronic kidney disease (CKD) is commonly associated with a high burden of comorbidities and poor clinical outcomes. Malnutrition–inflammation–atherosclerosis syndrome is common in the more severe stages of CKD, suggesting a close interplay for these three comorbid conditions. Both malnutrition and obesity are associated with a disturbed adipokine profile and inflammation, contributing to a higher risk of cardiovascular disease (CVD) events. Adiponectin and leptin have important roles in carbohydrate and lipid metabolism, and in the inflammatory process. The effects of adiponectin and leptin alterations in CKD, which are usually increased, and their association with the different comorbidities found in CKD, will be focused on to understand their crosstalk with the risk of CVD events. Nonetheless, although adiponectin and leptin contribute to a higher risk of CVD events, further studies are warranted to fully clarify their roles, especially when different comorbidities exist.

Severe Quantitative Scale of Acanthosis Nigricans in Neck is Associated with Abdominal Obesity, HOMA-IR, and Hyperlipidemia in Obese Children from Mexico City: A Cross-Sectional Study

Background. Acanthosis nigricans (AN) is a clinical sign that commonly occurs in obesity; however, its specificity and sensitivity have been controversial. It is unknown if AN severity degree can be a useful marker for cardiometabolic disorders screening. We suggest that the stratified analysis of AN severity degree in neck by Burke’s scale could be a useful tool in the screening of cardiometabolic alterations in obese children. Objective. The aim of this study was the association of AN severity degree in neck by Burke’s scale with anthropometric, biochemical, and inflammatory parameters in obese school-age children from Mexico City. Methods. A cross-sectional study was conducted, including 95 obese school-age children stratified by AN severity degree in neck by Burke’s scale. Anthropometric and fasting biochemical measurements were determined. Variables were compared by x2 test for frequencies and one-way ANOVA with Bonferroni posttest for continuous variables. Linear regression analysis adjusted by gender, BMI, and age was performed to evaluate the association between AN severity degree and cardiometabolic alterations. Statistical significance was set at $p<0.05$ . Results. As AN severity degree in neck by Burke’s scale increased, diastolic blood pressure ( $p=0.001$ ) and triglycerides ( $p=0.02$ ) significantly increased and adiponectin significantly decreased ( $p=0.02$ ). Positive associations between grade 3 AN and waist circumference, HOMA-IR, triglycerides, total cholesterol, and LDL cholesterol were observed. Conclusion. Our findings could be used to identify an easier clinical tool to prevent obesity progression and its complications in pediatrics. There are no similar studies.

Safflower (Carthamus tinctorius L.) oil could improve abdominal obesity, blood pressure, and insulin resistance in patients with metabolic syndrome: A randomized, double-blind, placebo-controlled clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Carthamus tinctorius L. (Safflower) has been widely recommended to treat metabolic disorders in traditional herbal medicine in Persia, China, Korea, Japan, and other East-Asian countries. The anti-hypercholesterolemic and antioxidant effects of this plant have been well documented, but its protective effects against Metabolic Syndrome (MetS) have not been fully illustrated.

AIM OF THE STUDY

The present study aimed to evaluate the effects of safflower oil on MetS risk factors.

MATERIALS AND METHODS

In this randomized, double-blind, placebo-controlled clinical trial, 67 patients with MetS were administered either divided 8 g safflower oil or placebo daily for 12 weeks. All patients were advised to follow their previous diets and physical activities.

RESULTS

Safflower oil resulted in a significant reduction in waist circumference (-2.42 ± 3.24 vs. 0.97 ± 2.53, p<0.001), systolic blood pressure (-8.80 ± 9.77 vs. -2.26 ± 8.56, p = 0.021), diastolic blood pressure (-3.53 ± 7.52 vs. -0.70 ± 6.21, p = 0.041), fasting blood sugar (-5.03 ± 10.62 vs. 2.94 ± 7.57, p = 0.003), and insulin resistance (-0.59 ± 1.43 vs. 0.50 ± 1, p = 0.012), but an increase in adiponectin level (0.38 ± 0.99 vs. -0.09 ± 0.81, p = 0.042) in the treatment group in comparison to the placebo group. The results revealed a direct relationship between leptin level and Body Mass Index (BMI) in both groups (p<0.001). In addition, increase in BMI resulted in a non-significant decrease in adiponectin level in both groups. Moreover, no significant difference was observed between the two groups regarding lipid profiles, leptin serum level, serum creatinine concentration, and other outcomes.

CONCLUSION

Safflower oil without lifestyle modification improved abdominal obesity, blood pressure, and insulin resistance in patients with MetS.

Higher Physical Activity Level Improves Leptin Concentrations in Spinal Cord Injury Subjects

The present study was designed to compare the body composition and indicators of chronic inflammatory grade, such as leptin, adiponectin, and resistin concentrations in irregularly active and active SCI subjects. Thirty-two male subjects participated in this study. They were divided into three groups: able-bodied control irregularly active (control, n = 11), irregularly active with SCI (SCI-IA, n = 8), and physically active with SCI (SCI-PA, n = 13). The enzyme-linked immunosorbent assay (ELISA) assessed serum concentrations of leptin, adiponectin, and resistin. All volunteers performed the maximum oxygen uptake (VO_2max) test, 24 h total energy expenditure (TEE), and body composition by skinfold thicknesses. Leptin concentrations were higher in the SCI-IA group when compared to the other groups, while no significant differences were found between the SCI-PA and control cohorts. In addition, no significant differences were found among groups for serum adiponectin and resistin concentrations either. The SCI-PA group showed significantly higher values for TEE and VO_2max when compared to the other groups. Percentages of body fat and circumference were decreased in the control and SCI-PA groups when compared to the SCI-IA cohort. Associations between leptin and cardiorespiratory capacity and anthropometric markers were also observed. Our findings highlight that the lack of physical activity in the SCI subjects leads to poor general physical fitness and higher levels of body adiposity, which may induce hyperleptinemia, an essential marker for cardiometabolic disorders.

Association of sex-specific differences in lipoprotein(a) concentrations with cardiovascular mortality in individuals with type 2 diabetes mellitus

Background

Compared to individuals without type 2 diabetes mellitus, the relative increase in cardiovascular mortality is much higher in women than in men in individuals with type 2 diabetes mellitus.

Methods

We evaluated data from 7443 individuals (3792 women, 50.9%), aged 20 to 81 years, from two independent population-based investigations, SHIP-0 and MONICA/KORA S3. We analyzed the longitudinal sex-specific associations of lipoprotein(a) with cardiovascular mortality in individuals with and without type 2 diabetes mellitus using Cox regression.

Results

During a median follow-up of 20.5 years (136,802 person-years), 657 participants (404 men and 253 women) died of cardiovascular causes. Among individuals without type 2 diabetes mellitus, men had a significantly higher risk for cardiovascular mortality compared to women in unadjusted model and after adjustment. On the other hand, in participants with type 2 diabetes mellitus, the risk for cardiovascular mortality was not different between men and women in the unadjusted model and after adjustment for age, body mass index, low-density lipoprotein-cholesterol, fasting status and study sample (SHIP-0, MONICA/KORA S3). Further adjustment for lipoprotein(a) concentrations had no impact on the hazard ratio (HR) for cardiovascular mortality comparing men versus women in individuals without type 2 diabetes mellitus [HR: 1.94; 95% confidence interval (CI) 1.63 to 2.32; p < 0.001]. In individuals with type 2 diabetes mellitus, however, further adjustment for lipoprotein(a) led to an increased risk for cardiovascular mortality in men and a decreased risk in women resulting in a statistically significant difference between men and women (HR: 1.53; 95% CI 1.04 to 2.24; p = 0.029).

Conclusions

Women are described to have a stronger relative increase in cardiovascular mortality than men when comparing individuals with and without type 2 diabetes mellitus. Higher lipoprotein(a) concentrations in women with type 2 diabetes mellitus than in men with type 2 diabetes mellitus might partially explain this finding.

The PREdictor of MAlnutrition in Systemic Sclerosis (PREMASS) Score: A Combined Index to Predict 12 Months Onset of Malnutrition in Systemic Sclerosis

Objective: Malnutrition is a severe complication in Systemic Sclerosis (SSc) and it is associated with significant mortality. Notwithstanding, there is no defined screening or clinical pathway for patients, which is hampering effective management and limiting the opportunity for early intervention. Here we aim to identify a combined index predictive of malnutrition at 12 months using clinical data and specific serum adipokines. Methods: This was an international, multicentre observational study involving 159 SSc patients in two independent discovery (n = 98) and validation (n = 61) cohorts. Besides routine clinical and serum data at baseline and 12 months, Malnutrition Universal Screening Tool (MUST) score and serum concentration of leptin and adiponectin were measured for each participant at baseline. The endpoint of malnutrition was defined according to European Society of Clinical Nutrition and Metabolism (ESPEN) recommendation. Significant parameters from univariate analysis were tested in logistic regression analysis to identify the predictive index of malnutrition in the derivation cohort. Results: The onset of malnutrition at 12 months correlated with adiponectin, leptin and their ratio (A/L), MUST, clinical subset, disease duration, Scl70 and Forced Vital Capaciy (FVC). Logistic regression analysis defined the formula: -2.13 + (A/L*0.45) + (Scl70*0.28) as the best PREdictor of MAlnutrition in SSc (PREMASS) (AUC = 0.96; 95% CI 0.93, 0.99). PREMASS < -1.46 had a positive predictive value (PPV) > 62% and negative predictive value (NPV) > 97% for malnutrition at 12 months. Conclusion: PREMASS is a feasible index which has shown very good performance in two independent cohorts for predicting malnutrition at 12 months in SSc. The implementation of PREMASS could aid both in clinical management and clinical trial stratification/enrichment to target malnutrition in SSc.

Assessment of Patients with Periorbital Melanosis for Hyperinsulinemia and Insulin Resistance

Background:

Periorbital melanosis (PM) is one of the most common dermatological condition seen in routine practice. Several cutaneous markers such as acanthosis nigricans have been associated with insulin resistance (IR). However, the association of PM with IR needs to be substantiated.

Objective:

The objective of the study is to evaluate the association of circulating adipokines and IR with PM.

Materials and Methods:

In this cross-sectional study, we recruited 100 patients with PM and 100 age- and gender-matched healthy controls. The serum levels of leptin, adiponectin, fasting glucose, fasting insulin, insulin-like growth factor-1 (IGF-1), homeostatic model assessment of insulin resistance (HOMA-IR), and leptin: adiponectin ratio (L/A ratio) were assayed.

Results:

The serum levels of leptin, fasting glucose, fasting insulin, HOMA-IR, L/A ratio were significantly higher in patients with PM as compared to controls. The serum levels of adiponectin were significantly lower in cases as compared to controls. On multivariate regression analysis, leptin, adiponectin, and HOMA-IR were found to be significant, even after adjusting for BMI, blood pressure and LDL and HDL cholesterol.

Conclusion:

Our findings suggest that patients with PM have hyperinsulinemia, IR, and elevated L/A ratio. PM as a marker of IR in adults may help in identifying patients early and thus aid in the early prevention and management of the disease.

Therapeutic Applications of Type 2 Diabetes Mellitus Drug Metformin in Patients with Osteoarthritis

Type 2 diabetes mellitus (T2DM) and osteoarthritis (OA) are common chronic diseases that frequently co-exist. The link between OA and T2DM is attributed to common risk factors, including age and obesity. Several reports suggest that hyperglycemia and accumulated advanced glycosylation end-products might regulate cartilage homeostasis and contribute to the development and progression of OA. Metformin is used widely as the first-line treatment for T2DM. The drug acts by regulating glucose levels and improving insulin sensitivity. The anti-diabetic effects of metformin are mediated mainly via activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), which is an energy sensing enzyme activated directly by an increase in the AMP/ATP ratio under conditions of metabolic stress. Dysregulation of AMPK is strongly associated with development of T2DM and metabolic syndrome. In this review, we discuss common risk factors, the association between OA and T2DM, and the role of AMPK. We also address the adaptive use of metformin, a known AMPK activator, as a new drug for treatment of patients with OA and T2DM.

Role of Adipokines in the Association between Thyroid Hormone and Components of the Metabolic Syndrome

Metabolic syndrome (MS) increases cardiovascular risk. The role of thyroid hormone on components of MS is unclear. We analyzed a sample of 4733 euthyroid subjects from SardiNIA study. In female thyrotropin (TSH) was significantly and positively associated with triglycerides (Standardized regression coefficients (β) = 0.081, p < 0.001). Free thyroxine (FT4) was positively associated with HDL (β = 0.056, p < 0.01), systolic blood pressure (SBP) (β = 0.059, p < 0.001), diastolic blood pressure (DBP) (β = 0.044, p < 0.01), and fasting glucose (β = 0.046, p < 0.01). Conversely, FT4 showed a negative association with waist circumference (β = −0.052, p < 0.001). In TSH was positively associated with triglycerides (β = 0.111, p < 0.001) and FT4 showed a positive association with DBP (β = 0.51, p < 0.01). The addition of leptin and adiponectin to the regression models did not substantially change the impact of thyroid hormones on components of MS. Our data suggest that, even within the euthyroid range, excess of truncal adipose tissue is associated with variations in FT4. Leptin and adiponectin exert an additive effect rather than a causal effect. Additional studies should be performed to determine the clinical significance of this finding.

Impairment of respiratory muscle strength in Berardinelli-Seip congenital lipodystrophy subjects

BACKGROUND

Berardinelli-Seip Congenital Generalized Lipodystrophy (BSCL) is an ultra-rare metabolic disease characterized by hypertriglyceridemia, hyperinsulinemia, hyperglycemia, hypoleptinemia, and diabetes mellitus. Although cardiovascular disturbances have been observed in BSCL patients, there are no studies regarding the Respiratory Muscle Strength (RMS) in this type of lipodystrophy. This study aimed to evaluate RMS in BSCL subjects compared with healthy subjects.

METHODS

Eleven individuals with BSCL and 11 healthy subjects matched for age and gender were included in this study. The Maximum Inspiratory Pressure (MIP), Maximum Expiratory Pressure (MEP), and Peripheral Muscle Strength (PMS) were measured for three consecutive years. BSCL subjects were compared to healthy individuals for MIP, MEP, and PMS. Correlations between PMS and MIP were also analyzed. The genetic diagnosis was performed, and sociodemographic and anthropometric data were also collected.

RESULTS

BSCL subjects showed significantly lower values for MIP and MEP (p <  0.0001 and p = 0.0002, respectively) in comparison to healthy subjects, but no changes in handgrip strength (p = 0.15). Additionally, we did not observe changes in MIP, MEP, and PMS two years after the first analysis, showing maintenance of respiratory dysfunction in BSCL subjects (p = 0.05; p = 0.45; p = 0.99). PMS and MIP were not correlated in these subjects (r = 0.56; p = 0.18).

CONCLUSION

BSCL subjects showed lower respiratory muscle strength when compared with healthy subjects; however, PMS was not altered. These findings were maintained at similar levels during the two years of evaluation. Our data reveal the first association of BSCL with the development of respiratory muscle weakness.

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.

Association between circulating adipocytokine concentrations and microvascular complications in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of controlled cross-sectional studies

BACKGROUND

The adipocytokines leptin and adiponectin have been variously associated with diabetic microvascular complications. No comprehensive clinical data exist examining the association between adipocytokines and the presence of these complications.

METHODS

This is a systematic review of cross-sectional studies comparing circulating adipocytokines in patients with type 2 diabetes mellitus (T2DM), with and without microvascular complications. Studies were retrieved from MEDLINE, EMBASE, Scopus and Cochrane databases. Study quality was evaluated using a modified Newcastle-Ottawa Scale. Meta-analysis was performed using an inverse-variance model, providing standardised mean differences (SMD) and 95% confidence intervals (CI). Heterogeneity was determined by I(2) statistic.

RESULTS

Amongst 554 identified studies, 28 were included in the review. Study quality range was 3.5-9 (maximum 11). Higher leptin levels were associated with microalbuminuria (SMD=0.41; 95% CI=0.14-0.67; n=901; p=0.0003), macroalbuminuria (SMD=0.68; 95% CI=0.30-1.06; n=406; p=0.0004), and neuropathy (SMD=0.26; 95% CI=0.07-0.44; n=609; p=0.008). Higher adiponectin levels were associated with microalbuminuria (SMD=0.55; 95% CI=0.29-0.81, n=274; p<0.001), macroalbuminuria (SMD=1.37; 95% CI=0.78-1.97, n=246; p<0.00001), neuropathy (SMD=0.25; 95% CI=0.14-0.36; n=1516; p<0.00001), and retinopathy (SMD=0.38; 95% CI=0.25-0.51; n=1306; p<0.00001). Meta-regression suggested no influence of body mass index and duration of diabetes on effect size, and a weak trend in terms of age on effect size.

DISCUSSION

Our meta-analysis suggests leptin and adiponectin levels are higher in T2DM patients with microvascular complications. Studies were limited by cross-sectional design. Large prospective analyses are required to validate these findings.

What is the best biomarker for metabolic syndrome diagnosis?

AIMS

There are three definitions belong to metabolic syndrome (MetS). These definitions have some differences that make some problem for MetS diagnosis criteria. So a new diagnosis marker can help to MetS diagnosis. The aim of this study was the assess of serum levels of leptin, total adiponectin, high molecular weight (HMW) adiponectin, and their ratio with MetS.

MATERIALS AND METHODS

We searched Science direct, Pubmed, and Google Scholar for related articles in English. Review studies excluded.

RESULTS

Of 1827 articles found, 16 articles met our inclusion criteria. leptin is higher in MetS group but adiponectin is lower (<4 μg/ml) and it shows the paradoxical effect of them in MetS. Higher L/A ratio is a better biomarker for MetS diagnosis criteria than leptin and adiponectin separately. HMW adiponectin (<2.5 μg/ml) can be the most reliable biomarker for MetS diagnosis criteria.

CONCLUSION

Our systematic review showed that HMW adiponectin and Leptin to adiponectin ratio should be the best biomarkers for MetS.

Association between serum adipocytokine levels and microangiopathies in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

It is thought that adipocytokines contribute to the increased risk of vascular complications in type 2 diabetes. However, there is still limited information on the relationship between microangiopathies and adipocytokines, such as adiponectin, leptin and tumor necrosis factor-α (TNF-α) in patients with type 2 diabetes.

MATERIALS AND METHODS

The present study examined the relationship between fasting serum adiponectin, leptin, and TNF-α levels and microangiopathies in Korean type 2 diabetes. A total of 153 patients were recruited and evaluated for diabetic nephropathy, retinopathy and neuropathy. Serum adiponectin, TNF-α and leptin levels were measured.

RESULTS

Serum adiponectin levels were significantly lower in patients with nephropathy than in those without nephropathy (P = 0.017), and were significantly higher in patients with retinopathy or neuropathy than those without retinopathy or neuropathy (P = 0.01 and P = 0.002, respectively). The mean levels of leptin were significantly higher in patients with neuropathy than in those without neuropathy (P = 0.002). The mean levels of TNF-α were not significantly different according to any of the three microangiopathies. Multivariate logistic regression analysis showed that the odds ratio for the presence of neuropathy in the highest tertile of adiponectin was 4.3 (95% confidence interval 1.59-11.62), as compared with the patients in the lowest tertile of adiponectin level.

CONCLUSIONS

Levels of adipocytokines were significantly different according to the presence of each microangiopathy. In particular, higher serum adiponectin was independently associated with increased odds for the presence of neuropathy. Future prospective studies with larger numbers of patients are required to establish a direct relationship between plasma adipocytokine concentrations and the development or severity of diabetic microangiopathies.

Determinants of insulin secretion and sensitivity in bangladeshi type 2 diabetic subjects

BACKGROUND

The relative contribution of insulin secretion and sensitivity in the development of type 2 diabetes mellitus (T2DM) vary from population to population due to the heterogeneous nature of the disease. The study was undertaken to evaluate the insulin secretory capacity and sensitivity in a Bangladeshi type 2 diabetic population and to explore the association of some of the anthropometric (BMI, WHR, MBP) and biochemical factors (glucose, lipids, HbA(1c)) known to modulate B-cell function and insulin action.

METHODS

Ninety three T2DM and 70 age-matched control subjects were studied for their fasting glucose, lipids, HbA(1c) (by HPLC) and C-peptide (by ELISA). Insulin secretion (HOMA B) and insulin sensitivity (HOMA S) were calculated by homeostasis model assessment (HOMA).

RESULTS

Both insulin secretion and sensitivity were significantly reduced in diabetic as compared to control subjects (HOMA B%, geometric M +/- SD, 34.67 +/- 1.73 vs 104.71 +/- 1.34, p < 0.001; HOMA S%, 67.60 +/- 1.69 vs 85.11 +/- 1.54, p < 0.01). However, the discriminant function coefficient for HOMA B (1.142) was about 1.5 times higher than that for HOMA S (0.731). In T2DM, HOMA B had positive correlation with BMI (r = 0.362, p < 0.001) and inverse correlation with plasma glucose (r = - 0.701, p < 0.001) and HbA1c (r = - 0.612, p < 0.001). HOMA S was inversely correlated to BMI (r = - 0.274, p < 0.01), WHR (r = - 0.252, p < 0.05), plasma total cholesterol (r = - 0.240, p < 0.05) and triglycerides (r = 0.301, p < 0.01).

CONCLUSIONS

Both insulin secretory dysfunction and insulin resistance are present in Bangladeshi T2DM subjects, but B-cell dysfunction seems to be the predominant defect. BMI, plasma glucose and insulin are the major determinants of insulin secretory capacity; and generalized as well as central obesity, plasma glucose, total cholesterol, triglycerides and insulin are among the major determinants of insulin sensitivity in this population.

Relationship between adipocytokines and cardiovascular risk factors in patients with type 2 diabetes mellitus

The aim of this study was to explore the relationship between serum profiles of adiponectin, leptin, resistin and visfatin and traditional and non-traditional cardiovascular risk factors in patients with type 2 diabetes mellitus (T2DM). A total of 85 patients with T2DM and 30 non-diabetic controls were enrolled in the study. Levels of adipocytokines (adiponectin, leptin, resistin and visfatin), lipids (total cholesterol, triglycerides), lipoproteins [HDL-cholesterol, LDL-cholesterol, lipoprotein (a)], apolipoproteins (Apo-A1 and Apo-B), non-traditional cardiovascular risk markers [asymmetric dimethylarginine (ADMA), homocysteine] and the inflammatory marker hs-CRP were measured, and anthropometric variables were determined. Serum adiponectin levels were decreased and leptin, resistin and visfatin levels were increased in T2DM patients compared to controls. They were associated with obesity (BMI), insulin resistance (HOMA-IR) and various markers of glucose/lipid profile, inflammation and endothelial dysfunction markers. These results suggest that decreased serum adiponectin and increased leptin, resistin and visfatin levels in T2DM may be novel biochemical risk factors for cardiovascular complications.

Autonomic dysregulation in ob/ob mice is improved by inhibition of angiotensin-converting enzyme

The leptin-deficient ob/ob mice are insulin resistant and obese. However, the control of blood pressure in this model is not well defined. The goal of this study was to evaluate the role of leptin and of the renin-angiotensin system in the cardiovascular abnormalities observed in obesity using a model lacking leptin. To this purpose, we measured blood pressure in ob/ob and control animals by radiotelemetry combined with fast Fourier transformation before and after both leptin and enalapril treatment. Autonomic function was assessed pharmacologically. Blood pressure during daytime was slightly higher in the ob/ob compared to control mice, while no difference in heart rate was observed. Blood pressure response to trimetaphane and heart rate response to metoprolol were greater in ob/ob mice than in control littermates indicating an activated sympathetic nervous system. Heart rate response to atropine was attenuated. Baroreflex sensitivity and heart rate variability were blunted in ob/ob mice, while low frequency of systolic blood pressure variability was found increased. Chronic leptin replacement reduced blood pressure and reversed the impaired autonomic function observed in ob/ob mice. Inhibition of angiotensin-converting enzyme by enalapril treatment had similar effects, prior to the loss of weight. These findings suggest that the renin-angiotensin system is involved in the autonomic dysfunction caused by the lack of leptin in ob/ob mice and support a role of this interplay in the pathogenesis of obesity, hypertension, and metabolic syndrome.

Role of adipocytokines in predicting the development of diabetes and its late complications

Diabetes is an important health problem since the incidence of diabetes is continuously increasing. Early diagnosis is important as type 2 diabetes begins long before we diagnose it, leading to a complicated course of the disease. In order to prevent delay in the diagnosis of type 2 diabetes, novel predictors and pathways for type 2 diabetes are mounting. Diabetic complications are common cause of morbidity and mortality among subjects with diabetes. In the pathogenesis of diabetic complications some factors other than chronic hyperglycemia may be involved. Adipocytokines play important roles in the pathogenesis of diabetes mellitus, insulin resistance, and associated metabolic conditions such as hypertension and dyslipidemia. The investigations on the role of adipocytokines in developing diabetes and its complications have been made. In this review, we discussed the implications of adipocytokines in predicting diabetes and diabetic complications, with particular attention on the roles of adiponectin, leptin, visfatin, and vaspin.

The Role of Asymmetric Dimethylarginine (ADMA) and Leptin in Hypertensive Patients

We investigated the role of leptin and asymmetric dimethylarginine (ADMA) in uncomplicated hypertension. We also investigated their relationship with insulin resistance and serum levels of several metabolic parameters, including homocysteine, lipoprotein(a) and malondialdehyde (MDA). A total of 34 untreated newly-diagnosed hypertensive patients (seven men and 27 women; mean age, 57.4 ± 10.1 years) and 38 normotensive healthy subjects (20 men and 18 women; mean age, 55.9 ± 8.7 years) were studied prospectively. Serum leptin, homocysteine, lipoprotein(a), MDA and insulin resistance (HOMA-IR) were significantly higher in hypertensive patients compared with normotensive subjects. There were no significant differences in ADMA, insulin-like growth factor-1 and insulin-like growth factor binding protein-3 between the two groups. No correlation was found between serum ADMA and leptin levels. Our findings suggest that high serum leptin and homocysteine levels, oxidative stress and insulin resistance may be important risk factors for atherosclerosis among patients with uncomplicated hypertension.

Serum leptin and its relation to anthropometric measures of obesity in pre-diabetic Saudis

Background

Little information is available on leptin concentrations in individuals with IGT. This study aims to determine and correlate leptin levels to anthropometric measures of obesity in pre-diabetic, (IFG and IGT), type 2 diabetic and normoglycaemic Saudis.

Methods

308 adult Saudis (healthy controls n = 80; pre-diabetes n = 86; Type 2 diabetes n = 142) participated. Anthropometric parameters were measured and fasting blood samples taken. Serum insulin was analysed, using a solid phase enzyme amplified sensitivity immunoassay and also leptin concentrations, using radio-immunoassay. The remaining blood parameters were determined using standard laboratory procedures.

Results

Leptin levels of diabetic and pre-diabetic men were higher than in normoglycaemic men (12.4 [3.2–72] vs 3.9 [0.8–20.0] ng/mL, (median [interquartile range], p = 0.0001). In females, leptin levels were significantly higher in pre-diabetic subjects (14.09 [2.8–44.4] ng/mL) than in normoglycaemic subjects (10.2 [0.25–34.8] ng/mL) (p = 0.046). After adjustment for BMI and gender, hip circumference was associated with log leptin (p = 0.006 with R2 = 0.086) among all subjects.

Conclusion

Leptin is associated with measures of adiposity, hip circumference in particular, in the non-diabetic state among Saudi subjects. The higher leptin level among diabetics and pre-diabetics is not related to differences in anthropometric measures of obesity.

Leptin is not associated independently with hypertension in Japanese-Brazilian women

We evaluated the relationship of leptin with hypertension adjusted for body mass index (BMI) and/or waist circumference in a population of Japanese-Brazilian women aged > or = 30 years with centrally distributed adiposity. After excluding diabetic subjects, the study subjects--who participated in a population-based study on the prevalence of metabolic syndrome--showed prevalence rates of obesity (BMI > or = 25 kg/m2) and central adiposity (waist > or = 80 cm) of 32.0 and 37.8%, respectively. The hypertensive group (N = 162) was older, had higher BMI (24.9 +/- 4.2 vs 23.3 +/- 3.4 kg/m2, P < 0.001), waist circumference (81.1 +/- 10.1 vs 76.3 +/- 8.2 cm, P < 0.001) and insulin levels (8.0 +/- 6.2 vs 7.1 +/- 4.9 microU/mL, P < 0.05) than the normotensive group (N = 322) and showed an unfavorable metabolic profile (higher 2-h plasma glucose, C-reactive protein and non-HDL cholesterol levels). Leptin did not differ between groups (8.2 +/- 6.8 vs 7.2 +/- 6.6 ng/mL, P = 0.09, for hypertensive vs normotensive, respectively) and its levels correlated significantly with anthropometric variables but not with blood pressure. Logistic regression analysis indicated that age and waist were independently associated with hypertension but not with homeostasis model assessment of insulin resistance or leptin levels. The lack of an independent association of hypertension with metabolic parameters (2-h glucose, C-reactive protein and non-HDL cholesterol) after adjustment for central adiposity suggested that visceral fat deposition may be the common mediator of the disturbances of the metabolic syndrome. Our data indicate that age and waist are major determinants of hypertension in this population of centrally obese (waist > or = 80 cm) Japanese-Brazilian women, but do not support a role for leptin in the elevation of blood pressure.

Impact of adiposity and plasma adipocytokines on diabetic angiopathies in Japanese Type 2 diabetic subjects

AIMS

Adipocytokines, products from adipose tissue, have biological activities on the vascular system, and may affect diabetic angiopathy. In this study, we assessed the relationship between adiposity and plasma adipocytokine levels, and investigated the clinical significance of adiposity and plasma adipocytokine levels on diabetic micro- and macroangiopathy in Type 2 diabetic subjects.

METHODS

We studied 231 Japanese Type 2 diabetic subjects (135 men and 96 women, aged 60.4 +/- 12.3 years, body mass index 24.8 +/- 5.2 kg/m2). We measured adipocytokine [adiponectin, leptin, resistin, and tumour necrosis factor (TNF)-alpha] levels, lipid profiles and urine albumin excretion. We also performed optic fundus examination and measured carotid intramedia thickness (IMT) using B-mode ultrasonography, and the localization of fat with abdominal computed tomography. A group of 93 subjects with microalbuminuria or overt proteinuria was compared with the other 148 to assess the effect on nephropathy. A group of 191 eyes with simple retinopathy or more advanced changes was compared with 263 eyes without retinal changes to assess the effect on retinopathy.

RESULTS

Plasma adiponectin level was negatively correlated with both visceral (r = -0.37, P < 0.01) and subcutaneous (r = -0.25, P < 0.01) fat areas. Resistin concentration was positively related with visceral fat area (r = 0.15, P < 0.05). Adiponectin concentration was positively correlated with age (r = 0.26, P < 0.01). TNF-alpha was correlated with IMT (r = 0.16, P < 0.05) after correction for age. Logistic regression analysis indicates a 4085 times greater chance of having retinopathy with a one unit increase in TNF-alpha (pmol/l) and a 30.64 times greater chance of having nephropathy with one unit increase in leptin (nmol/l).

CONCLUSIONS

The present observations suggest that visceral and subcutaneous fat has an impact on microangiopathy as well as macroangiopathy, possibly through different adipocytokines.

Decreased plasma adiponectin levels in young obese males

Plasma adiponectin levels are reduced in middle-aged obesity and in patients with type 2 diabetes and coronary artery disease. The purpose of this study was to investigate the effects of early-aged obesity on plasma adiponectin level. Twenty-six male college students (19.2 +/- 1.1 years, obese group: n = 15, [body mass index > 25, percent body fat > 25%], non-obese group: n = 11) participated in the present study. We measured anthropometric parameters and plasma adiponectin and leptin level. Plasma adiponectin levels in the obese group were significantly lower than those in the non-obese group (obese: 4.7 +/- 2.0 micro g/ml, non-obese: 6.8 +/- 2.2 micro g/ml, p < 0.05). On the other hand, plasma leptin levels in the obese group were significantly higher than those in the non-obese group (obese: 8.4 +/- 3.2 ng/ml, non-obese: 2.6 +/- 2.1 ng/ml, p < 0.001). Plasma adiponectin levels were significantly correlated with body weight (r = -0.415, p < 0.05) and percent body fat (r = -0.412, p < 0.05). Stepwise multiple regression analysis revealed that percent body fat was a significant independent predictor of plasma adiponectin level (r = 0.406, p < 0.05). These results show that obesity is associated with reduced plasma adiponectin even in young subjects.

Effects of leptin on expression of acyl-coenzymea: cholesterol acyltransferases-1 in cultured human monocyte-macrophages

To investigate the effects of leptin on expression of acyl-coenzymeA: cholesterol acyl-transferases-1 (ACAT-1) in monocyte-macrophage differentiation, human monocytic cells (THP-1) were cultured in RPMI 1640 and made to differentiate into macrophages under the incubation with phorbol myristate acetate (PMA) for 48 h. The cells were divided into 4 groups according to different intervention factors as follows: MCs cultured in RPM11640 medium with 10% FBS for 48 h served as MC group (control group), MCs cultured in medium with serum-free RPM11640 containing 5% BSA, 100 nmol/L PMA for 48 h as MP group, MCs cultured in RPMI1640 medium with 10% FBS, 10 micromol/ml leptin for 48 h as leptin-MC group, and MCs cultured in medium with serum-free RPMI1640 containing 5% BSA. 100 nmol/L PMA, and 10 micromol/ml leptin for 48 h as leptin-MP group. Immunocytochemistry, reverse transcription polymerase chain reaction (RT-PCR) and Western blot were performed, respectively, to observe the effects of leptin on expression of ACAT-1 in the monocyte-macrophage differentiation. Our results showed that expression of ACAT-1 protein and mRNA in MP-group is two times that in MC-group (P<0.05), and the expression of ACAT-1 protein and mRNA increased by up to 4 folds in leptin-MP group-as compared with that of MC group (P<0.01). Thus, our results support the idea that expression of ACAT-1 increases more in cultured human macrophages than in monocytes, and leptin can significantly promote ACAT-1 expression. It was concluded that high expression of ACAT-1 may accelerate the development of human atherogenesis, and leptin might participate in atherogenesis by increasing expression of ACAT-1.

Serum leptin is elevated in Saudi Arabian patients with metabolic syndrome and coronary artery disease

AIMS

To compare plasma leptin in Saudi subjects with Type 2 diabetes and coronary heart disease (CHD) with non-diabetic control subjects and to examine the relationship of plasma leptin to other CHD risk factors.

RESEARCH DESIGN AND METHOD

Serum leptin concentrations were measured in 144 Saudi men. Subjects studied included 59 with Type 2 diabetes mellitus [BMI 27.5 (3.7) kg/m2 mean (sd)], 34 with coronary heart disease [BMI 29.6 (1.8) kg/m2], and 51 non-diabetic controls [BMI 28.0 (3.5) kg/m2]. There was no significant difference in BMI between the groups. Fasting serum leptin, lipids, insulin, apolipoproteins and glucose were measured. BMI, blood pressure; smoking habit and age were also recorded. Insulin resistance was assessed using the HOMA model.

RESULTS

Leptin concentrations were significantly higher in diabetic and CHD patients than in controls (P = 0.024 and 0.016, respectively). Multiple regression analysis showed that body weight (P < 0.0006), serum triglyceride concentration (P = 0.046) and systolic blood pressure (P = 0.013) were all significantly related to the logarithm of the serum leptin concentration (R2 = 0.549) in CHD patients. A subgroup analysis, comparing those patients who had the metabolic syndrome, as defined by WHO, with controls, showed higher serum leptin in those with metabolic syndrome (P = 0.05).

CONCLUSIONS

Serum leptin is increased in Saudi subjects with diabetes mellitus, metabolic syndrome and CHD. Leptin may be a marker of risk of CHD, at least in men, and contribute to the CHD risk profile in subjects with insulin resistance. Further studies are needed to evaluate this relationship prospectively.