The metabolic significance of leptin in humans: gender-based differences in relationship to adiposity, insulin sensitivity, and energy expenditure

Clinical effectiveness and predictors of response to topiramate plus lifestyle modification in youth with obesity seen in a weight management clinical setting

Introduction

Obesity affects approximately 20% of U.S. youth. Anti-obesity medications (AOMs) are promising lifestyle modification adjuncts for obesity treatment, and topiramate is commonly prescribed in pediatric weight management clinics. It is important to determine "real-world" effectiveness of AOMs and, given shifts towards personalized approaches, characteristics potentially predicting better or worse response. We therefore sought to describe clinical effectiveness from topiramate plus lifestyle modification, and to determine if baseline phenotypic characteristics are associated with better or worse response.

Methods

We performed a retrospective cohort study (2012-2020) among youth (<18 years old) followed in a U.S. academic-based weight management clinic. Baseline characteristics (i.e., body mass index (BMI), liver function tests, eating-related behaviors) and outcomes (%BMI of 95th percentile (%BMIp95), BMI, percent %BMI change, weight) were determined through review of electronic health records and clinic intake survey data.

Results

Among 282 youth prescribed topiramate plus lifestyle modifications (mean baseline age 12.7 years, %BMIp95 144%), %BMIp95 and percent BMI change were statistically significantly reduced at each time point (1.5-, 3-, 6-, and 12-month %BMIp95 reductions: -2.2, -3.9, -6.6, and -9.3 percentage points, respectively; percent BMI reduction: -1.2%, -1.9%, -3.2%, and -3.4%, respectively; all p<0.01). Considering multiple comparisons, no baseline characteristics statistically significantly predicted response at any time point.

Conclusions

We found that topiramate plus lifestyle modification reduced %BMIp95 and BMI among youth in a weight management clinical setting, and that no baseline characteristics evaluated were associated with response. These results should be considered preliminary given the observational nature of this study, and prospective studies are needed to further characterize clinical effectiveness and identify and confirm potential predictors of response.

Leptin resistance in children with in utero exposure to maternal obesity and gestational diabetes

BACKGROUND

Leptin resistance occurs with obesity, but it is unknown if individuals at risk for obesity develop leptin resistance prior to obesity.

OBJECTIVE

Investigate whether leptin resistance is independent of weight status in children at risk for obesity due to intrauterine exposure to maternal obesity or gestational diabetes mellitus (GDM).

METHODS

Mother-child dyads (N = 179) were grouped by maternal pregnancy weight and GDM status: (1) normal weight, no GDM; (2) overweight/obesity, no GDM; (3) overweight/obesity with GDM. Children (4-10 years) were further stratified by current body mass index (BMI) <85th or ≥85th percentile. Leptin resistance of children and mothers was calculated as fasting leptin/fat mass index. Two-way ANOVA was used to assess whether leptin concentrations and leptin resistance differed by current weight status or in utero exposure group, after adjusting for race, sex and Tanner stage.

RESULTS

Children with a BMI ≥85th percentile had more leptin resistance than those with a BMI <85th percentile (p < 0.001), but leptin resistance did not differ by in utero exposure. Similarly, leptin resistance in women was associated with weight status and not prior GDM.

CONCLUSIONS

Results suggest that leptin concentrations are associated with obesity but not risk for obesity based on in utero exposure to maternal obesity or GDM.

Elevated plasma leptin levels are associated with vascular access dysfunction in patients on maintenance hemodialysis

BACKGROUND

Inflammation has been associated with vascular access (VA) dysfunction. The adipocytokine leptin can directly induce pro-inflammatory T helper 1 immune responses and the pathogenesis of chronic inflammation. We explored the association between plasma leptin and VA dysfunction in patients on maintenance hemodialysis (HEMO).

METHODS

A total of 344 consecutive patients who received anastomosis for VA at a single HEMO center between June 1, 2010 and December 31, 2021 were screened. Of these patients, 267 met the inclusion criteria and were included. ELISA was used to measure circulating levels of leptin.

RESULTS

The VA dysfunction group had a higher leptin level than the patent VA group. A higher concentration of leptin was independently and significantly associated with an elevated risk of VA dysfunction. Multiple logistic regression analysis showed that leptin, female sex, and hypertension were independently associated with VA dysfunction, even after adjusting for known biomarkers. We then evaluated the ability of leptin, female sex, and hypertension to predict the risk of VA dysfunction, and the area under the curve (AUC) for leptin was 0.626 (p = 0.0001). When leptin, female sex, and hypertension were added to this multivariate model, the AUC increased to 0.679 (p = 0.001) for leptin and hypertension, and 0.690 for leptin, hypertension, and female sex (p = 0.004). In addition, plasma leptin levels were associated with sex, body mass index, and hemoglobin.

CONCLUSIONS

In addition to the association between leptin and VA dysfunction, hypertension and female sex independently predicted VA dysfunction in patients with HEMO.

Association between visceral obesity and 10-year risk of first atherosclerotic cardiovascular diseases events among American adults: National Health and Nutrition Examination Survey

Background

In the United States, the relationship between visceral obesity and the risk of developing atherosclerosis cardiovascular disease (ASCVD) for the first time in 10 years is unclear.

Methods

Data for this cross-sectional study came from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020. We collected variable information related to 10-year ASCVD risk and visceral obesity reliable indicators [Visceral obesity index (VAI) and Lipid accumulation product (LAP)]. And we used multiple logistic regression to analyze the correlation of visceral obesity indicators (VAI and LAP) with 10-year ASCVD risk. In addition, we assessed the linear relationship between VAI or LAP and 10-year ASCVD risk by smoothing curve fitting. Finally, we conducted subgroup analysis and sensitivity analysis after excluding participants with extreme VAI and LAP values to ensure that we obtained accurate and reliable results.

Results

Our study included a total of 1,547 participants (mean age: 56.5 ± 10.1, 60% of males). The results of the multiple logistic regression showed that compared with participants with the lowest VAI in the 1st Quartile (≤0.79), the adjusted OR values for VAI and elevated 10-year ASCVD risk in Q3 (1.30-2.14), and Q4 (≥2.15) were 2.58 (95% CI: 1.24-5.36, P = 0.011), 15.14 (95% CI: 6.93-33.05, P < 0.001), respectively. Compared with participants with the lowest LAP in the 1st Quartile (≤28.29), the adjusted OR values for VAI and elevated 10-year ASCVD risk in Q3 (46.52-77.00), and Q4 (≥77.01) were 4.63 (95% CI: 2.18-9.82, P < 0.001), 16.94 (95% CI: 6.74-42.57, P < 0.001), respectively. Stratified analysis showed that the association between VAI or LAP and the first ASCVD event was more pronounced in males.

Conclusion

Higher VAI or LAP scores are significantly associated with elevated 10-year ASCVD risk in adults aged 40 to 79 in the USA, which suggested that monitoring visceral obesity is crucial to reduce the risk of a first ASCVD event.

High frequency of autoimmune thyroiditis in euthyroid girls with premature adrenarche

Objective

The purpose of this study was to investigate the frequency of autoimmune thyroiditis (AT) among euthyroid prepubertal girls presenting with premature adrenarche (PA). We also aimed to identify the clinical, metabolic, and endocrine profile of girls with AT and concurrent PA and compare them to girls with AT without PA, PA alone and healthy controls.

Methods

Ninety-one prepubertal girls aged 5-10 years, who attended our department for AT, PA and normal variants of growth and puberty were recruited for the study: 73 girls had PA, 6 AT without PA and 12 were referred for investigation of growth. All girls underwent clinical examination, detailed biochemical and hormonal screen. Standard dose Synachten stimulation test (SDSST) and oral glucose tolerance test (OGTT) were performed in all girls with PA. The whole study population was divided in 4 groups: Group PA-/AT+ included 6 girls with AT without PA; Group PA+/AT- PA subjects without AT; Group PA+/AT+ girls with PA and concomitant AT; Group PA-/AT- twelve healthy girls without PA nor AT (controls).

Results

Among 73 girls presenting with PA 19 had AT (26%). BMI, systolic blood pressure (SBP) and the presence of goiter significantly differed between the four groups (p = 0.016, p = 0.022 and p < 0.001, respectively). When comparing hormonal parameters among the four groups significant differences were found in leptin (p = 0.007), TSH (p = 0.044), anti-TPO (p = 0.002), anti-TG (p = 0.044), IGF-BP1 (p = 0.006), Δ4-Α (p = 0.01), DHEA-S (p = <0.001), IGF-1 (p = 0.012) and IGF-BP3 (p = 0.049) levels. TSH levels were significantly higher in Group PA+/AT+ compared to PA+/AT- and PA-/AT- (p = 0.043 and p = 0.016, respectively). Moreover, girls with AT (Groups PA-/AT+ and PA+/AT+) had higher TSH levels than those in Group PA+/AT- (p = 0.025). Girls in Group PA+/AT + showed higher cortisol response at 60 min post-SDSST than girls in Group PA+/AT- (p = 0.035). During the OGTT, insulin concentrations at 60 min were significantly higher in Group PA+/AT + compared to Group PA+/AT- (p = 0.042).

Conclusion

A high frequency of AT among euthyroid prepubertal girls with PA was observed. The combination of PA with AT even in euthyroid state may be associated with a greater degree of insulin resistance, than PA alone.

Obesity as a Risk Factor for Dementia and Alzheimer's Disease: The Role of Leptin

Obesity is a growing worldwide health problem, affecting many people due to excessive saturated fat consumption, lack of exercise, or a sedentary lifestyle. Leptin is an adipokine secreted by adipose tissue that increases in obesity and has central actions not only at the hypothalamic level but also in other regions and nuclei of the central nervous system (CNS) such as the cerebral cortex and hippocampus. These regions express the long form of leptin receptor LepRb, which is the unique leptin receptor capable of transmitting complete leptin signaling, and are the first regions to be affected by chronic neurocognitive deficits, such as mild cognitive impairment (MCI) and Alzheimer's Disease (AD). In this review, we discuss different leptin resistance mechanisms that could be implicated in increasing the risk of developing AD, as leptin resistance is frequently associated with obesity, which is a chronic low-grade inflammatory state, and obesity is considered a risk factor for AD. Key players of leptin resistance are SOCS3, PTP1B, and TCPTP whose signalling is related to inflammation and could be worsened in AD. However, some data are controversial, and it is necessary to further investigate the underlying mechanisms of the AD-causing pathological processes and how altered leptin signalling affects such processes.

The association of appetite and hormones (leptin, ghrelin, and Insulin) with resting metabolic rate in overweight/ obese women: a case-control study

Objective

Low resting metabolic rate (RMR), as a risk factor for weight gain and obesity, can be influenced by many factors. Empirical research has confirmed the role of appetite and related hormones in obesity and energy intake. This study aimed to investigate the relationship between appetite and related hormones in overweight or obese Iranian women with normal and hypo RMR.

Methods

This case–control study was conducted on 42 Iranian adult women (21 cases, and 21 controls), aged 18–48 years. An impedance body analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. The Flint questionnaire was used to assess appetite, dietary intake, and physical activity were assessed by FFQ and IPAQ questionnaires respectively, and ELISA kits were used to assess leptin, ghrelin, and insulin hormones.

Results

The results of the study demonstrated a negative association between ghrelin hormone level (β = -0.34, 95%CI = -61.70,-3.86, P-value = 0.027) and RMR, and a positive association between insulin hormone level (β = 0.48, 95%CI = 9.38–34.35, P-value = 0.001) and RMR. Also, results of the appetite questionnaire showed that, in general, both appetite (β = 0.32, 95%CI = -0.10–2.99 P-value = 0.044) and hunger variable (β = 0.30, 95%CI = 0.04–5.87, P-value = 0.047) have a positive association with RMR. There was no significant association between leptin levels and RMR.

Conclusion

It is evident that appetite and related hormones have a potential role in promoting a normal RMR.

Association of Serum Adipokines and Resting Energy Expenditure in Patients With Chronic Kidney Disease

Background and Aim

Metabolic disorders are prevalent in patients with chronic kidney disease (CKD) and may lead to protein energy wasting (PEW). Adipokines improve connections between PEW and energy metabolism. We aimed to determine the relationship between adipokine levels and resting energy expenditure (REE) in patients with CKD.

Methods

A total of 208 patients in non-dialyzed CKD stages 3–5 were enrolled in this cross-sectional study. Serum adipokines (leptin, adiponectin, and interleukin 6 (IL-6) were measured using enzyme-linked immunosorbent assay. Patient's REE was measured using indirect calorimetry. Fat mass (FM) and lean tissue mass (LTM) were measured using multiple-frequency bioimpedance analysis. Spearman correlation analyses and multivariate linear regression models were used to assess the association between serum adipokines and REE.

Results

The mean age was 52.7 ± 14.6 years, and 26.9, 26.4, and 46.7% of our participants had CKD stages 3, 4, and 5, respectively. The median values of serum adiponectin, leptin, and IL-6 were 470.4 (range, 291.1–802.2), 238.1 (range, 187.9–418.4), and 4.0 (range, 2.4–9.5) pg/mL, respectively. The male participants had significantly lower FM% (P = 0.001) and lower leptin levels (P < 0.001) than the female participants. After adjusting for age, diabetes, high-sensitivity C-reactive protein, intact parathyroid hormone, LTM, and FM, multiple linear regression analysis revealed that serum leptin levels were significantly positively associated with REE in men rather than in women (P < 0.05). Serum adiponectin levels were inversely associated with REE in men, but this association disappeared while FM was additionally adjusted. Adiponectin levels in women were not correlated with REE (P > 0.05). IL-6 was not significantly associated with REE in either men or women.

Conclusions

A sex-specific relationship between serum adipokines (leptin and adiponectin) and REE was observed in patients with CKD stages 3–5, which was partly confounded by FM.

Sex-Specific Catabolic Metabolism Alterations in the Critically Ill following High Dose Vitamin D

Pharmacological interventions are essential for the treatment and management of critical illness. Although women comprise a large proportion of the critically ill, sex-specific pharmacological properties are poorly described in critical care. The sex-specific effects of vitamin D₃ treatment in the critically ill are not known. Therefore, we performed a metabolomics cohort study with 1215 plasma samples from 428 patients from the VITdAL-ICU trial to study sex-specific differences in the metabolic response to critical illness following high-dose oral vitamin D₃ intervention. In women, despite the dose of vitamin D₃ being higher, pharmacokinetics demonstrated a lower extent of vitamin D₃ absorption compared to men. Metabolic response to high-dose oral vitamin D₃ is sex-specific. Sex-stratified individual metabolite associations with elevations in 25(OH)D following intervention showed female-specific positive associations in long-chain acylcarnitines and male-specific positive associations in free fatty acids. In subjects who responded to vitamin D₃ intervention, significant negative associations were observed in short-chain acylcarnitines and branched chain amino acid metabolites in women as compared to men. Acylcarnitines and branched chain amino acids are reflective of fatty acid B oxidation, and bioenergesis may represent notable metabolic signatures of the sex-specific response to vitamin D. Demonstrating sex-specific pharmacometabolomics differences following intervention is an important movement towards the understanding of personalized medicine.

Resting Energy Expenditure Is Not Altered in Children and Adolescents with Obesity. Effect of Age and Gender and Association with Serum Leptin Levels

In children and adolescents, obesity does not seem to depend on a reduction of resting energy expenditure (REE). Moreover, in this young population, the interactions between either age and obesity or between age and gender, or the role of leptin on REE are not clearly understood. To compare the levels of REE in children and adolescents we studied 181 Caucasian individuals (62% girls) classified on the basis of age- and sex-specific body mass index (BMI) percentile as healthy weight (n = 50), with overweight (n = 34), or with obesity (n = 97) and in different age groups: 8–10 (n = 38), 11–13 (n = 50), and 14–17 years (n = 93). REE was measured by indirect calorimetry and body composition by air displacement plethysmography. Statistically significant differences in REE/fat-free mass (FFM) regarding obesity or gender were not observed. Absolute REE increases with age (p < 0.001), but REE/FFM decreases (p < 0.001) and there is an interaction between gender and age (p < 0.001) on absolute REE showing that the age-related increase is more marked in boys than in girls, in line with a higher FFM. Interestingly, the effect of obesity on absolute REE is not observed in the 8–10 year-old group, in which serum leptin concentrations correlate with the REE/FFM (r = 0.48; p = 0.011). In conclusion, REE/FFM is not affected by obesity or gender, while the effect of age on absolute REE is gender-dependent and leptin may influence the REE/FFM in 8–10 year-olds.

Effects of exercise and diet intervention on appetite-regulating hormones associated with miRNAs in obese children

AIMS

This study investigated the effects of exercise and diet intervention on appetite-regulating hormones and subjective appetite changes in obese children and examined expressions of specific key microRNAs (miRNA, miR).

METHODS

16 obese children were included in a training program consisting of exercise and diet intervention for 6 weeks. Before and after the intervention, fasting blood was collected to determine appetite-regulating hormones (leptin, ghrelin, and orexin) and miRNA (miR-103a-3p and miR-200a-3p) levels; eating behavior of the children was reported using the Children Eating Behavior Questionnaire (CEBQ).

RESULTS

The level of orexin was significantly decreased (P < 0.05), while ghrelin was significantly enhanced (P < 0.05) after 6 weeks. The scores of food responsiveness (FR) and enjoyment of food (EF) of the CEBQ were significantly decreased (P < 0.05) after intervention. The changes of leptin and that of SR were significantly correlated (r = - 0.455, P < 0.05), and the correlation between the alterations of orexin and that of EF was moderate with significance (r = 0.625, P < 0.05). miR-103a-3p expression was not statistically changed, while miR-200a-3p was significantly inhibited after 6-week intervention (P < 0.05). The correlation between relative changes of miR-103a-3p and that of leptin and orexin were both with significant difference (r = 0.413, P < 0.05; r = 0.409, P < 0.05), whereas the alterations of miR-200a-3p were not correlative with hormones or appetite sensation.

CONCLUSION

Exercise combined with diet intervention for 6 weeks was effective in regulating appetite sensations and hormones in obese children, and miR-103a-3p and miR-200a-3p might provide a foundation for target biomarkers of appetite trait in modulating the energy balance control by exercise and dietary intervention.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

TRIAL REGISTRATION

The trial was registered in ClinicalTrials.gov (NCT03762629).

Skeletal glucocorticoid signalling determines leptin resistance and obesity in aging mice

Objective

Aging and chronic glucocorticoid excess share a number of critical features, including the development of central obesity, insulin resistance and osteoporosis. Previous studies have shown that skeletal glucocorticoid signalling increases with aging and that osteoblasts mediate the detrimental skeletal and metabolic effects of chronic glucocorticoid excess. Here, we investigated whether endogenous glucocorticoid action in the skeleton contributes to metabolic dysfunction during normal aging.

Methods

Mice lacking glucocorticoid signalling in osteoblasts and osteocytes (HSD2^OB/OCY-tg mice) and their wild-type littermates were studied until 3, 6, 12 and 18 months of age. Body composition, adipose tissue morphology, skeletal gene expression and glucose/insulin tolerance were assessed at each timepoint. Leptin sensitivity was assessed by arcuate nucleus STAT3 phosphorylation and inhibition of feeding following leptin administration. Tissue-specific glucose uptake and adipose tissue oxygen consumption rate were also measured.

Results

As they aged, wild-type mice became obese and insulin-resistant. In contrast, HSD2^OB/OCY-tg mice remained lean and insulin-sensitive during aging. Obesity in wild-type mice was due to leptin resistance, evidenced by an impaired ability of exogenous leptin to suppress food intake and phosphorylate hypothalamic STAT3, from 6 months of age onwards. In contrast, HSD2^OB/OCY-tg mice remained leptin-sensitive throughout the study. Compared to HSD2^OB/OCY-tg mice, leptin-resistant wild-type mice displayed attenuated sympathetic outflow, with reduced tyrosine hydroxylase expression in both the hypothalamus and thermogenic adipose tissues. Adipose tissue oxygen consumption rate declined progressively in aging wild-type mice but was maintained in HSD2^OB/OCY-tg mice. At 18 months of age, adipose tissue glucose uptake was increased 3.7-fold in HSD2^OB/OCY-tg mice, compared to wild-type mice.

Conclusions

Skeletal glucocorticoid signalling is critical for the development of leptin resistance, obesity and insulin resistance during aging. These findings underscore the skeleton's importance in the regulation of body weight and implicate osteoblastic/osteocytic glucocorticoid signalling in the aetiology of aging-related obesity and metabolic disease.

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As they aged, wild-type CD1 mice became hyperphagic, obese and insulin-resistant.

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Mice lacking skeletal glucocorticoid signalling (HSD2^OB/OCY-tg) were lean and healthy.

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Unlike wild-type mice, HSD2^OB/OCY-tg mice remained leptin-sensitive during aging.

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Adipose tissue sympathetic outflow was maintained in aging HSD2^OB/OCY-tg mice.

Using proximity extension proteomics assay to discover novel biomarkers associated with circulating leptin levels in patients with type 2 diabetes

We aimed to discover novel associations between leptin and circulating proteins which could link leptin to the development of cardiovascular disease in patients with type 2 diabetes (T2DM). In a discovery phase, we investigated associations between 88 plasma proteins, assessed with a proximity extension assay, and plasma leptin in a cohort of middle-aged patients with T2DM. Associations passing the significance threshold of a False discovery rate of 5% (corresponding to p < 0.0017) were replicated in patients with T2DM in an independent cohort. We also investigated if proteins mediated the longitudinal association between plasma leptin and the incidence of major cardiovascular events (MACE). One protein, adipocyte fatty acid binding protein (A-FABP), was significantly associated with leptin in both the discovery phase [95% CI (0.06, 0.17) p = 0.00002] and the replication cohort [95% CI (0.12, 0.39) p = 0.0003]. Multiplicative interaction analyses in the two cohorts suggest a stronger association between A-FABP and leptin in men than in women. In longitudinal analyses, the association between leptin and MACE was slightly attenuated after adding A-FABP to the multivariate model. Our analysis identified a consistent association between leptin and A-FABP in two independent cohorts of patients with T2DM, particularly in men.Trial registration: ClinicalTrials.gov identifier NCT01049737.

Differential Expression of Ormdl Genes in the Islets of Mice and Humans with Obesity

The orosomucoid-like (Ormdl) proteins play a critical role in sphingolipid homeostasis, inflammation, and ER stress, all of which are associated with obesity and βcell dysfunction. However, their roles in β cells and obesity remain unknown. Here, we show that islets from overweight/obese human donors displayed marginally reduced ORMDL1-2 expression, whereas ORMDL3 expression was significantly downregulated compared with islets from lean donors. In contrast, Ormdl3 was substantially upregulated in the islets of leptin-deficient obese (ob/ob) mice compared with lean mice. Treatment of ob/ob mice and their islets with leptin markedly reduced islet Ormld3 expression. Ormdl3 knockdown in a β cell line induced expression of pro-apoptotic markers, which was rescued by ceramide synthase inhibitor fumonisin B1. Our results reveal differential expression of Ormdl3 in the islets of a mouse model and humans with obesity, highlight the potential effect of leptin in this differential regulation, and suggest a role for Ormdl3 in β cell apoptosis.

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Islets of overweight/obese human donors display markedly reduced ORMDL3 expression

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Ormdl3 expression was significantly upregulated in the islets of ob/ob mice

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Leptin treatment markedly reduced Ormld3 expression in the islets of ob/ob mice

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Fumonisin B1 restores increased apoptotic marker levels induced by Ormdl3 silencing

Chronic Obstructive Pulmonary Disease in Women: A Biologically Focused Review with a Systematic Search Strategy

Purpose

Evidence suggests that chronic obstructive pulmonary disease (COPD) symptoms and progression may differ between men and women. However, limited information is currently available on the pathophysiological and biological factors that may underlie these sex-related differences. The objective of this review is to systematically evaluate reports of potential sex-related differences, including genetic, pathophysiological, structural, and other biological factors, that may influence COPD development, manifestation, and progression in women.

Patients and Methods

A PubMed literature search was conducted from inception until January 2020. Original reports of genetic, hormonal, and physiological differences, and biological influences that could contribute to COPD development, manifestation, and progression in women were included.

Results

Overall, 491 articles were screened; 29 articles met the inclusion criteria. Results from this analysis demonstrated between-sex differences in inflammatory, immune, genetic, structural, and physiological factors in patients with COPD.

Conclusion

Various biological differences are observed between men and women with COPD including differences in inflammatory and metabolic pathways related to obesity and fat distribution, immune cell function and autophagy, extent and distribution of emphysema and airway wall remodeling. An enhanced understanding of these differences has the potential to broaden our understanding of how COPD develops and progresses, thereby providing an opportunity to ultimately improve diagnosis, treatment, and monitoring of COPD in both men and women.

Current Diagnosis, Treatment and Clinical Challenges in the Management of Lipodystrophy Syndromes in Children and Young People

Lipodystrophy is a heterogeneous group of disorders characterized by lack of body fat in characteristic patterns, which can be genetic or acquired. Lipodystrophy is associated with insulin resistance that can develop in childhood and adolescence, and usually leads to severe metabolic complications. Diabetes mellitus, hypertriglyceridemia, and hepatic steatosis ordinarily develop in these patients, and most girls suffer from menstrual abnormalities. Severe complications develop at a relatively young age, which include episodes of acute pancreatitis, renal failure, cirrhosis, and complex cardiovascular diseases, and all of these are associated with serious morbidity. Treatment of lipodystrophy consists of medical nutritional therapy, exercise, and the use of anti-hyperglycemic and lipid-lowering agents. New treatment modalities, such as metreleptin replacement, promise much in the treatment of metabolic abnormalities secondary to lipodystrophy. Current challenges in the management of lipodystrophy in children and adolescents include, but are not limited to: (1) establishing specialized centers with experience in providing care for lipodystrophy presenting in childhood and adolescence; (2) optimizing algorithms that can provide some guidance for the use of standard and novel therapies to ensure adequate metabolic control and to prevent complications; (3) educating patients and their parents about lipodystrophy management; (4) improving patient adherence to chronic therapies; (5) reducing barriers to access to novel treatments; and (5) improving the quality of life of these patients and their families.

Determinants of Circulating Soluble Leptin Receptor and Free Leptin Index in Indonesian Pre-Pubertal Obese Male Children: A Preliminary Cross-Sectional Study

PURPOSE

This study aimed to investigate the clinical and metabolic determinants of circulating soluble leptin receptor (CSLR) and free leptin index (FLI) in pre-pubertal obese male children.

METHODS

We conducted a preliminary cross-sectional study at three tertiary hospitals and one public primary school. Eighty obese male children without growth and developmental abnormalities aged 5-9 years were recruited. In these children, obesity was solely caused by excessive food intake, and not by acute illness, medications, endocrine abnormalities, or any syndrome. Body mass index (BMI), body fat mass, carbohydrate intake, fat intake, high density lipoprotein cholesterol level, low density lipoprotein cholesterol level, triglyceride level, and Homeostatic Model Assessment for Insulin Resistance are the potential determinants for leptin regulation, which is represented by CSLR level and FLI.

RESULTS

Carbohydrate was the main source of energy. BMI and body fat mass had negative weak correlation with CSLR and positive weak correlation with FLI. Furthermore, carbohydrate intake was found to be independently associated with CSLR based on the results of the multiple linear regression analysis. Following an increase in carbohydrate intake, CSLR level decreased progressively without any negative peak.

CONCLUSION

Leptin regulation in prepubertal obese male children is associated with body composition and dietary intake. Carbohydrate intake is useful for predicting CSLR. Lipid profiles and insulin resistance are not related to both CSLR and FLI. Treatment and prevention of leptin resistance in obese children should focus on reducing BMI, fat mass, and carbohydrate intake.

Circulating CRP Levels Are Associated with Epicardial and Visceral Fat Depots in Women with Metabolic Syndrome Criteria

Sexual dimorphism accounts for significant differences in adipose tissue mass and distribution. However, how the crosstalk between visceral and ectopic fat depots occurs and which are the determinants of ectopic fat expansion and dysfunction remains unknown. Here, we focused on the impact of gender in the crosstalk between visceral and epicardial fat depots and the role of adipocytokines and high-sensitivity C-reactive protein (hs-CRP). A total of 141 outward patients (both men and women) with one or more defining criteria for metabolic syndrome (MetS) were consecutively enrolled. For all patients, demographic and clinical data were collected and ultrasound assessment of visceral adipose tissue (VFth) and epicardial fat (EFth) thickness was performed. Hs-CRP and adipocytokine levels were assessed by enzyme-linked immunosorbent assay (ELISA). Men were characterized by increased VFth and EFth (p-value < 0.001 and 0.014, respectively), whereas women showed higher levels of adiponectin and leptin (p-value < 0.001 for both). However, only in women VFth and EFth significantly correlated between them (p = 0.013) and also with leptin (p < 0.001 for both) and hs-CRP (p = 0.005 and p = 0.028, respectively). Linear regression confirmed an independent association of both leptin and hs-CRP with VFth in women, also after adjustment for age and MetS (p = 0.012 and 0.007, respectively). In conclusion, men and women present differences in epicardial fat deposition and systemic inflammation. An intriguing association between visceral/epicardial fat depots and chronic low-grade inflammation also emerged. In women Although a further validation in larger studies is needed, these findings suggest a critical role of sex in stratification of obese/dysmetabolic patients.

Sex-specific roles of cellular inflammation and cardiometabolism in obesity-associated depressive symptomatology

BACKGROUND

Obesity and depression are complex conditions with stronger comorbid relationships among women than men. Inflammation and cardiometabolic dysfunction are likely mechanistic candidates for increased depression risk, and their prevalence differs by sex. Whether these relationships extend to depressive symptoms is poorly understood. Therefore, we analyzed sex in associations between inflammation and metabolic syndrome (MetS) criteria on depressive symptomatology. Specifically, we examined whether sex positively moderates the relationship between depressive symptoms and inflammation among women, and whether MetS has parallel effects among men.

METHODS

Depressive symptoms, MetS, and inflammation were assessed in 129 otherwise healthy adults. Depressive symptoms were assessed using Beck Depression Inventory (BDI-Ia). Monocyte inflammation regulation (BARIC) was quantified using flow cytometry measurement of TNF-α suppression by β-agonist. Moderation effects of sex on associations between BARIC, MetS criteria, and BDI were estimated using two-way ANOVA and linear regression, adjusting for BMI, and by sex subgroup analyses.

RESULTS

Obese individuals reported more depressive symptoms. Sex did not formally moderate this relationship, though BDI scores tended to differ by BMI among women, but not men, in subgroup analysis. Poorer inflammation control and higher MetS criteria were correlated with somatic depressive symptoms. Sex moderated associations between MetS criteria and somatic symptoms; among men, MetS criteria predicted somatic symptoms, not among women. Subgroup analysis further indicated that poorer inflammation control tended to be associated with higher somatic symptoms in women.

CONCLUSIONS

These results indicate that obesity-related inflammation and MetS factors have sex-specific effects on depressive symptoms in a non-clinical population. Although pathophysiological mechanisms underlying sex differences remain to be elucidated, our findings suggest that distinct vulnerabilities to depressive symptoms exist between women and men, and highlight the need to consider sex as a key biological variable in obesity-depression relationships. Future clinical studies on comorbid obesity and depression should account for sex, which may optimize therapeutic strategies.

Sex Bias in Asthma Prevalence and Pathogenesis

Sex-related differences in asthma prevalence are well established and change through the reproductive phases of life. As children, boys have increased prevalence of asthma compared to girls. However, as adults, women have increased prevalence of asthma compared to men. Many factors, including genetics, environment, immunological responses, and sex hormones, affect the sex disparity associated with the development and control of asthma and other allergic diseases. Fluctuations of hormones during puberty, menstruation, pregnancy, and menopause, alter asthma symptoms and severity. In this article, we review clinical and epidemiological studies that examined the sex disparity in asthma and other allergic diseases as well as the role of sex hormones on asthma pathogenesis.

Bariatric Surgery Resistance: Using Preoperative Lifestyle Medicine and/or Pharmacology for Metabolic Responsiveness

Bariatric surgery is an effective and durable treatment for individuals with obesity and its associated comorbidities. However, not all patients meet weight loss and/or cardiometabolic goals following bariatric surgery, suggesting that some people are bariatric surgery resistant. The reason for this resistance is unclear, but potential factors, such as adiposity-derived inflammation, insulin resistance, hyperglycemia, and aerobic fitness prior to surgery, have been related to blunted surgery responsiveness. Exercise, diet, and/or pharmacology are effective at reducing inflammation and improving insulin action as well as physical function. Herein, we present data that supports the novel hypothesis that intervening prior to surgery can enhance disease resolution in people who are resistant to bariatric surgery.

Omentectomy Prevents Metabolic Syndrome By Reducing Appetite and Body Weight In A Diet-Induced Obesity Rat Model

Visceral fat deposition is associated with impairment of glucose and lipid metabolism while leptin levels are frequently related to subcutaneous fat area. At present, there is considerable controversy regarding the role of visceral adipose tissue accumulation in the development of metabolic syndrome (MS). Here we show the effects of omentectomy on the liver and MS in a diet induced obesity rat model. Our results reveal that undergoing omentectomy previously the establishment of the diet-induced-obesity reduced significantly body weight gain and avoid the development of MS, including non-alcoholic fatty liver disease. Intriguingly, the significantly lower body weight gain was due to decreased food intake. Omentum drives obesity progression through leptin resistance mediated by C-reactive protein, Interleucin (IL)-6 and high lipolysis activity. Omentum removal reversed immediately the increased plasma levels of CRP and IL-6 and gradually food intake, weight gain, and features of MS in diet-induced-obesity. Omentectomy caused no changes in normal-weigh-rats. This report displays causal mechanism by which omentum promotes obesity and propose omentectomy as a promising procedure in MS prevention.

Do gender and ethnic differences in fasting leptin in Indians and Creoles of Mauritius persist beyond differences in adiposity?

Recent body composition studies on the island of Mauritius in young adults belonging to the two main ethnicities-Indians (South Asian descent) and Creoles (African/Malagasy descent)-have shown gender-specific ethnic differences in their body mass index (BMI)-Fat% relationships. We investigated here whether potential gender and ethnic differences in blood leptin would persist beyond that explained by differences in body composition. In healthy young adult Mauritian Indians and Creoles (79 men and 80 women; BMI range: 15-41 kg m^-2), we investigated the relationships between fasted serum leptin with BMI, waist circumference (WC), total fat% assessed by deuterium oxide dilution technique and central adiposity (trunk fat%) assessed by abdominal bioimpedance analysis. The results indicate that the greater elevations in leptin-BMI and leptin-WC regression lines in women compared with men, as well as in Indian men compared with Creole men, are abolished when BMI and WC are replaced by total body fat% and trunk fat%, respectively. In women, no significant between-ethnic difference is observed in total body fat%, trunk fat% and serum leptin. Thus, in young adult Mauritians, a population at high risk for later cardiometabolic diseases, the differences in body fat% entirely accounted for the observed gender and ethnic differences in serum leptin.

Sex matters: The effects of biological sex on adipose tissue biology and energy metabolism

Adipose tissue is a complex and multi-faceted organ. It responds dynamically to internal and external stimuli, depending on the developmental stage and activity of the organism. The most common functional subunits of adipose tissue, white and brown adipocytes, regulate and respond to endocrine processes, which then determine metabolic rate as well as adipose tissue functions. While the molecular aspects of white and brown adipose biology have become clearer in the recent past, much less is known about sex-specific differences in regulation and deposition of adipose tissue, and the specific role of the so-called pink adipocytes during lactation in females. This review summarises the current understanding of adipose tissue dynamics with a focus on sex-specific differences in adipose tissue energy metabolism and endocrine functions, focussing on mammalian model organisms as well as human-derived data. In females, pink adipocytes trans-differentiate during pregnancy from subcutaneous white adipocytes and are responsible for milk-secretion in mammary glands. Overlooking biological sex variation may ultimately hamper clinical treatments of many aspects of metabolic disorders.

Adiposity and hyperleptinemia during the first trimester among pregnant women with preeclampsia

BACKGROUND

Leptin levels start increasing from the early stages of pregnancy, irrespective of the maternal body mass index. Leptin levels are increased in pregnant women with preeclampsia (PE) and may precede the clinical onset of the disease, with peaks occurring around 28 weeks of gestation. This study was aimed at determining whether serum leptin concentration and body fat percentage are significantly altered during the first trimester in pregnancies that subsequently develop PE and whether such changes are useful in predicting the disease.

MATERIALS AND METHODS

This was a prospective longitudinal study conducted among pregnant women in Ho municipality. A cohort of 314 pregnant women was monitored from the first antenatal visit to delivery period at the Volta Regional Hospital, Ho, Ghana. Maternal serum leptin and lipid profile were analyzed and body fat percentage determined during first trimester. Body mass index was also calculated.

RESULTS

First trimester serum leptin level (P<0.0001) and body fat percentage (P<0.0001) were significantly higher in those who developed PE than those who did not; while triglycerides (P=0.8600), total cholesterol (P=0.5620), high-density lipoprotein (P=0.5880), low-density lipoprotein (P=0.4870) and very low-density lipoprotein (P=0.6540) did not show any significant difference between those with PE and those without PE.

CONCLUSION

Leptin levels are increased significantly during the first trimester of pregnancy in obese women with PE, and these increases precede the onset of PE.

Corticotropin-releasing factor overexpression in mice abrogates sex differences in body weight, visceral fat, and food intake response to a fast and alters levels of feeding regulatory hormones

BACKGROUND

Corticotropin-releasing factor overexpressing (CRF-OE) male mice showed an inhibited feeding response to a fast, and lower plasma acyl ghrelin and Fos expression in the arcuate nucleus compared to wild-type (WT) mice. We investigated whether hormones and hypothalamic feeding signals are impaired in CRF-OE mice and the influence of sex.

METHODS

Male and female CRF-OE mice and WT littermates (4-6 months old) fed ad libitum or overnight fasted were assessed for body, adrenal glands and perigonadal fat weights, food intake, plasma hormones, blood glucose, and mRNA hypothalamic signals.

RESULTS

Under fed conditions, compared to WT, CRF-OE mice have increased adrenal glands and perigonadal fat weight, plasma corticosterone, leptin and insulin, and hypothalamic leptin receptor and decreased plasma acyl ghrelin. Compared to male, female WT mice have lower body and perigonadal fat and plasma leptin but higher adrenal glands weights. CRF-OE mice lost these sex differences except for the adrenals. Male CRF-OE and WT mice did not differ in hypothalamic expression of neuropeptide Y (NPY) and proopiomelanocortin (POMC), while female CRF-OE compared to female WT and male CRF-OE had higher NPY mRNA levels. After fasting, female WT mice lost more body weight and ate more food than male WT, while CRF-OE mice had reduced body weight loss and inhibited food intake without sex difference. In male WT mice, fasting reduced plasma insulin and leptin and increased acyl ghrelin and corticosterone while female WT showed only a rise in corticosterone. In CRF-OE mice, fasting reduced insulin while leptin, acyl ghrelin and corticosterone were unchanged with no sex difference. Fasting blood glucose was higher in CRF-OE with female > male. In WT mice, fasting increased hypothalamic NPY expression in both sexes and decreased POMC only in males, while in CRF-OE mice, NPY did not change, and POMC decreased in males and increased in females.

CONCLUSIONS

These data indicate that CRF-OE mice have abnormal basal and fasting circulating hormones and hypothalamic feeding-related signals. CRF-OE also abolishes the sex difference in body weight, abdominal fat, and fasting-induced feeding and changes in plasma levels of leptin and acyl ghrelin.

Body mass index and the risk of cancer incidence in patients with type 2 diabetes in Japan: Results from the National Center Diabetes Database

AIMS/INTRODUCTION

Both type 2 diabetes and obesity increase the risk of some types of cancers, and underlying mechanisms are thought to be, at least in part, common. In the present study, we carried out a retrospective cohort study of the relationship between body mass index (BMI) categories and cancer development in Japanese type 2 diabetic patients.

MATERIALS AND METHODS

A total of 113 incident cancers including 35 cancers whose incidence was reported to be increased by obesity (27 colorectal cancers, two breast cancers in postmenopausal women, one endometrial cancer, four renal cancers and one gallbladder cancer) were identified in 2,334 type 2 diabetic patients (1,616 men and 718 women) over an average observation period of 5.1 years.

RESULTS

In men, there was no significant association between the BMI categories at the start of the observation period and the development of any cancer. In contrast, the incidence of all of the cancers in the women was significantly higher in the group with a BMI of less than 22.0 kg/m2 (hazard ratio 3.07, 95% CI 1.01-9.36). In either sex, there was no significant relationship between the BMI categories and the development of cancers whose risk is known to be increased by obesity.

CONCLUSIONS

The findings of the present study were limited by the relatively small number of patients in the cohort, which posed a danger of not finding significance. However, the results suggested that obesity did not become an additional risk factor for cancer in Japanese type 2 diabetic patients.

Perinatal triphenyl phosphate exposure accelerates type 2 diabetes onset and increases adipose accumulation in UCD-type 2 diabetes mellitus rats

Triphenyl phosphate (TPhP) is a flame retardant additive frequently found in consumer products and household dust. We administered 170μg of TPhP in maternal food from gestational day 8.5 to weaning and evaluated metabolic phenotypes of 3.5 month old male and female rats, and weight-matched males up to 6 months, to assess the development of obesity and type 2 diabetes mellitus (T2DM), respectively. Perinatal TPhP exposure increased body and fat mass in 3.5 month old male and female rats, while leptin and cumulative energy intake were elevated in males and females, respectively. Independent of body mass, perinatal TPhP exposure accelerated T2DM onset in males and increased plasma non-esterified- fasting fatty acids. These observations suggest that perinatal exposure to TPhP exacerbates the development of obesity in male and female UCDavis-T2DM rats and accelerates T2DM onset in male UCD-T2DM rats.

Relationship between serum leptin and insulin resistance among obese Nigerian women

Background:

Leptin is a hormone produced directly from adipocytes and has been associated with type 2 diabetes mellitus (T2DM) which is characterized by insulin resistance (IR). Due to the increasing prevalence of obesity in sub-Saharan Africa, serum leptin can be explored as a predictive risk factor for T2DM. Therefore, the aim of this study was to determine the relationship between serum leptin and IR among obese women.

Methods:

This was a cross-sectional study of obese, adult Nigerian females. Participants with body mass index (BMI) ≥30 kg/m² and nondiabetic were recruited as subjects. Fasting serum leptin, insulin, and plasma glucose were determined. IR was calculated using the formula: Homeostatic model assessment-IR (HOMA-IR) = (glucose × insulin)/22.5. Statistical analyses were performed using SPSS and P < 0.05 was considered to be significant.

Results:

Eighty obese females with mean ± standard deviation BMI 39.1 ± 7.2 kg/m² and serum leptin level 48.4 ± 24.4 ng/ml participated in study. Prevalence of hyperleptinemia was 92.5% (confidence interval: 87.3–97.7%). The relationship between leptin and HOMA-IR among the subjects was: BMI 30–34.9 kg/m²: n = 27, r = 0.18, P = 0.42; BMI 35–39.9 kg/m²: n = 24, r = 0.36, P = 0.11; BMI ≥ 40 kg/m²: n = 29, r = 0.52, P = 0.004*; and after controlling for BMI (n = 29, r = 0.46, P = 0.014*). Multiple linear regression showed that leptin did not predict for IR (P = 0.837).

Conclusion:

Serum leptin levels were positively correlated with IR, which was significant among the Class III (morbid) obesity class. However, leptin was not a predictive factor for IR in obese Nigerian women.

Maternal obesity (Class I-III), gestational weight gain and maternal leptin levels during and after pregnancy: a prospective cohort study

BACKGROUND

Maternal obesity is accompanied by maternal and fetal complications during and after pregnancy. The risks seem to increase with degree of obesity. Leptin has been suggested to play a role in the development of obesity related complications. Whether maternal leptin levels differ between obese and morbidly obese women, during and after pregnancy, have to our knowledge not been previously described. Neither has the association between maternal leptin levels and gestational weight gain in obese women. The aim was to evaluate if maternal plasma leptin levels were associated with different degrees of maternal obesity and gestational weight gain.

METHODS

Prospective cohort study including women categorized as obesity class I-III (n = 343) and divided into three gestational weight gain groups (n = 304). Maternal plasma leptin was measured at gestational week 15, 29 and 10 weeks postpartum. Maternal Body Mass Index (BMI) was calculated from early pregnancy weight. Gestational weight gain was calculated using maternal weight in delivery week minus early pregnancy weight. The mean value and confidence interval of plasma-leptin were analysed with a two-way ANOVA model. Interaction effect between BMI and gestational weight gain group was tested with a two-way ANOVA model.

RESULTS

The mean maternal leptin concentrations were significantly higher in women with obesity class III compared to women in obesity class I, at all times when plasma leptin were measured. The mean leptin concentrations were also significantly higher in women with obesity class II compared to women in obesity class I, except in gestational week 29. There was no difference in mean levels of plasma leptin between the gestational weight gain groups. No significant interaction between BMI and gestational weight gain group was found.

CONCLUSIONS

Plasma leptin levels during and after pregnancy were associated with obesity class but not with degree of gestational weight gain. These results are in concordance with epidemiological findings where the risk of obstetric complications increases with increased maternal obesity class. The effect on obstetric outcome by degree of gestational weight gain is less pronounced than the adverse effects associated with maternal obesity.

Adipose Tissue Depots and Their Cross-Sectional Associations With Circulating Biomarkers of Metabolic Regulation

BACKGROUND

Visceral adipose tissue (VAT) and fatty liver differ in their associations with cardiovascular risk compared with subcutaneous adipose tissue (SAT). Several biomarkers have been linked to metabolic derangements and may contribute to the pathogenicity of fat depots. We examined the association between fat depots on multidetector computed tomography and metabolic regulatory biomarkers.

METHODS AND RESULTS

Participants from the Framingham Heart Study (n=1583, 47% women) underwent assessment of SAT, VAT, and liver attenuation. We measured circulating biomarkers secreted by adipose tissue or liver (adiponectin, leptin, leptin receptor, fatty acid binding protein 4, fetuin-A, and retinol binding protein 4). Using multivariable linear regression models, we examined relations of fat depots with biomarkers. Higher levels of fat depots were positively associated with leptin and fatty acid binding protein 4 but negatively associated with adiponectin (all P<0.001). Associations with leptin receptor, fetuin-A, and retinol binding protein 4 varied according to fat depot type or sex. When comparing the associations of SAT and VAT with biomarkers, VAT was the stronger correlate of adiponectin (β=-0.28 [women]; β=-0.30 [men]; both P<0.001), whereas SAT was the stronger correlate of leptin (β=0.62 [women]; β=0.49 [men]; both P<0.001; P<0.001 for comparing VAT versus SAT). Although fetuin-A and retinol binding protein 4 are secreted by the liver in addition to adipose tissue, associations of liver attenuation with these biomarkers was not stronger than that of SAT or VAT.

CONCLUSIONS

SAT, VAT, and liver attenuation are associated with metabolic regulatory biomarkers with differences in the associations by fat depot type and sex. These findings support the possibility of biological differences between fat depots.

Antibiotic perturbation of the murine gut microbiome enhances the adiposity, insulin resistance, and liver disease associated with high-fat diet

Background

Obesity, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD) are serious health concerns, especially in Western populations. Antibiotic exposure and high-fat diet (HFD) are important and modifiable factors that may contribute to these diseases.

Methods

To investigate the relationship of antibiotic exposure with microbiome perturbations in a murine model of growth promotion, C57BL/6 mice received lifelong sub-therapeutic antibiotic treatment (STAT), or not (control), and were fed HFD starting at 13 weeks. To characterize microbiota changes caused by STAT, the V4 region of the 16S rRNA gene was examined from collected fecal samples and analyzed.

Results

In this model, which included HFD, STAT mice developed increased weight and fat mass compared to controls. Although results in males and females were not identical, insulin resistance and NAFLD were more severe in the STAT mice. Fecal microbiota from STAT mice were distinct from controls. Compared with controls, STAT exposure led to early conserved diet-independent microbiota changes indicative of an immature microbial community. Key taxa were identified as STAT-specific and several were found to be predictive of disease. Inferred network models showed topological shifts concurrent with growth promotion and suggest the presence of keystone species.

Conclusions

These studies form the basis for new models of type 2 diabetes and NAFLD that involve microbiome perturbation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-016-0297-9) contains supplementary material, which is available to authorized users.

Leptin Induces Hypertension and Endothelial Dysfunction via Aldosterone-Dependent Mechanisms in Obese Female Mice

Obesity is a major risk factor for cardiovascular disease in males and females. Whether obesity triggers cardiovascular disease via similar mechanisms in both the sexes is, however, unknown. In males, the adipokine leptin highly contributes to obesity-related cardiovascular disease by increasing sympathetic activity. Females secrete 3× to 4× more leptin than males, but do not exhibit high sympathetic tone with obesity. Nevertheless, females show inappropriately high aldosterone levels that positively correlate with adiposity and blood pressure (BP). We hypothesized that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in females. Leptin control of the cardiovascular function was analyzed in female mice sensitized to leptin via the deletion of protein tyrosine phosphatase 1b (knockout) and in agouti yellow obese hyperleptinemic mice (Ay). Hypersensitivity to leptin (wild-type, 115 ± 2; protein tyrosine phosphatase 1b knockout, 124 ± 2 mm Hg; P<0.05) and obesity elevated BP (a/a, 113 ± 1; Ay, 128 ± 7 mm Hg; P<0.05) and impaired endothelial function. Chronic leptin receptor antagonism restored BP and endothelial function in protein tyrosine phosphatase 1b knockout and Ay mice. Hypersensitivity to leptin and obesity reduced BP response to ganglionic blockade in both strains and plasma catecholamine levels in protein tyrosine phosphatase 1b knockout mice. Hypersensitivity to leptin and obesity significantly increased plasma aldosterone levels and adrenal CYP11B2 expression. Chronic leptin receptor antagonism reduced aldosterone levels. Furthermore, chronic leptin and mineralocorticoid receptor blockade reduced BP and improved endothelial function in both leptin-sensitized and obese hyperleptinemic female mice. Together, these data demonstrate that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in female mice and suggest that obesity leads to cardiovascular disease via sex-specific mechanisms.

Leptin is associated with mood status and metabolic homeostasis in patients with bipolar disorder

BACKGROUND

Patients with bipolar disorder are at a high risk for becoming obese. Adipokines are associated with depression and obesity via the inflammatory process. However, few studies have investigated the associations between depression and leptin, adiponectin and resistin levels in patients with bipolar disorder. We explored the associations between serum levels of leptin, adiponectin and resistin and mood and metabolic status in patients with bipolar disorder.

METHODS

Body mass index (BMI) and serum leptin, adiponectin and resistin levels were assessed in 94 Korean patients with bipolar disorder. The Hamilton Rating Scale for Depression-17 and the Young Mania Rating Scale were used to assess mood state.

RESULTS

Leptin (17.19 ± 13.08 vs. 10.47 ± 10.05 ng/ml; p = 0.008) and adiponectin (10.51 ± 8.37 vs. 5.91 ± 2.82 μg/ml; p = 0.001) levels were higher in female than in male patients. After adjusting for mood state, age, smoking, alcohol habit, and BMI in a multivariate analysis of covariance (MANCOVA), leptin (17.86 ± 1.22 vs. 10.05 ± 1.48 ng/ml; p < 0.001) and adiponectin (10.18 ± 0.98 vs. 6.40 ± 1.19 μg/ml; p = 0.027) levels were still higher in female than in male patients. Compared to euthymic patients, depressed patients had higher levels of leptin (17.37 ± 14.69 vs. 11.65 ± 9.04 ng/ml; p = 0.024), but there was no significant difference in adiponectin and resistin levels between the two groups. After adjusting for age, gender and BMI in the MANCOVA, leptin levels were also significantly higher in depressed (16.78 ± 1.34 ng/ml) than in euthymic patients (10.73 ± 1.22 ng/ml; p = 0.001).

CONCLUSION

Leptin is closely associated with the regulation of mood and metabolic homeostasis in patients with bipolar disorder.

Association of diethylhexyl phthalate with obesity-related markers and body mass change from birth to 3 months of age

BACKGROUND

Several studies have suggested potential links of phthalates to obesity in children and adults. Limited evidence, however, has been available for the relations between diethylhexyl phthalate (DEHP) and obesity-related markers or body mass change in early life.

METHODS

128 healthy pregnant women were recruited and, after delivery, their newborns' first urine and umbilical cord blood samples were collected. We measured urinary levels of two DEHP metabolites, mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP). We also measured the levels of leptin, total cholesterol and triglyceride (TG) in cord serum, and used them along with weight, length, head circumference and ponderal index (PI, 100 g/cm(3)) at birth, as obesity-related markers, and estimated the relations between DEHP metabolites and obesity-related markers using generalised linear models. For the evaluation of body mass increase by early life DEHP exposure, body mass index (BMI) z-score change during 3 months after birth by DEHP metabolites in the first urine samples of the newborns were evaluated using logistic regression.

RESULTS

DEHP exposure was associated with decrease of PI and increase of TG (PI, β=-0.11, p=0.070 and TG, β=0.14, p=0.027), especially for boys (PI, β=-0.13, p=0.021; and TG, β=0.19, p=0.025). Moreover, DEHP exposure was positively associated with body mass increase during 3 months after birth (change of BMI z-scores, OR=4.35, p=0.025).

CONCLUSIONS

Our findings suggest that DEHP exposure may affect body mass change in early life through changes of obesity-related markers.

Chronic cocaine use and its association with myocardial steatosis evaluated by 1H magnetic resonance spectroscopy in African Americans

OBJECTIVES

Cardiac steatosis is a manifestation of ectopic fat deposition and is associated with obesity. The impact of chronic cocaine use on obesity measures and on the relationship between obesity measures and cardiac steatosis is not well-characterized. The objectives of this study were to compare obesity measures in chronic cocaine users and nonusers, and to explore which factors, in addition to obesity measures, are associated with myocardial triglyceride in African Americans, using noninvasive magnetic resonance spectroscopy.

METHODS

Between June 2004 and January 2014, 180 healthy African American adults without HIV infection, hypertension, and diabetes were enrolled in an observational proton magnetic resonance spectroscopy and imaging study investigating factors associated with cardiac steatosis.

RESULTS

Among these 180 participants, 80 were chronic cocaine users and 100 were nonusers. The median age was 42 (interquartile range, 34-47) years. Obesity measures trended higher in cocaine users than in nonusers. The median myocardial triglyceride was 0.6% (interquartile range, 0.4%-1.1%). Among the factors investigated, years of cocaine use, leptin, and visceral fat were independently associated with myocardial triglyceride. Body mass index and visceral fat, which were significantly associated with myocardial triglyceride in noncocaine users, were not associated with myocardial triglyceride content in cocaine users.

CONCLUSIONS

This study shows (1) cocaine users may have more fat than nonusers and (2) myocardial triglyceride is independently associated with duration of cocaine use, leptin, and visceral fat in all subjects, whereas leptin and high-density lipoprotein cholesterol, but not visceral fat or body mass index, in cocaine users, suggesting that chronic cocaine use may modify the relationships between obesity measures and myocardial triglyceride.

Gender Specific Association of Serum Leptin and Insulinemic Indices with Nonalcoholic Fatty Liver Disease in Prediabetic Subjects

Adipose tissue-derived hormone leptin plays a functional role in glucose tolerance through its effects on insulin secretion and insulin sensitivity which also represent the risk factors for nonalcoholic fatty liver disease (NAFLD). The present study explored the gender specific association of serum leptin and insulinemic indices with NAFLD in Bangladeshi prediabetic subjects. Under a cross-sectional analytical design a total of 110 ultrasound examined prediabetic subjects, aged 25-68 years consisting of 57.3% male (55.6% non NAFLD and 44.4% NAFLD) and 42.7% female (57.4% non NAFLD and 42.6% NAFLD), were investigated. Insulin secretory function (HOMA%B) and insulin sensitivity (HOMA%S) were calculated from homeostasis model assessment (HOMA). Serum leptin showed significant positive correlation with fasting insulin (r = 0.530, P = 0.004), postprandial insulin (r = 0.384, P = 0.042) and HOMA-IR (r = 0.541, P = 0.003) as well as significant negative correlation with HOMA%S (r = -0.388, P = 0.046) and HOMA%B (r = -0.356, P = 0.039) in male prediabetic subjects with NAFLD. In multiple linear regression analysis, log transformed leptin showed significant positive association with HOMA-IR (β = 0.706, P <0.001) after adjusting the effects of body mass index (BMI), triglyceride (TG) and HOMA%B in male subjects with NAFLD. In binary logistic regression analysis, only log leptin [OR 1.29 95% (C.I) (1.11-1.51), P = 0.001] in male subjects as well as HOMA%B [OR 0.94 95% (C.I) (0.89-0.98), P = 0.012], HOMA-IR [OR 3.30 95% (C.I) (0.99-10.95), P = 0.049] and log leptin [OR 1.10 95% (C.I) (1.01-1.20), P = 0.026] in female subjects were found to be independent determinants of NAFLD after adjusting the BMI and TG. Serum leptin seems to have an association with NAFLD both in male and female prediabetic subjects and this association in turn, is mediated by insulin secretory dysfunction and insulin resistance among these subjects.

Ghrelin, adipokines, metabolic factors in relation with weight status in school-children and results of a 1-year lifestyle intervention program

BACKGROUND

Overweight in Guadeloupe is a public health matter affecting children and adults. In the present study we evaluated the metabolic profile, including serum ghrelin, leptin and adiponectin levels, in normal weight, overweight and obese school children and we analyzed the potential changes in anthropometric and metabolic risk factors after a 1-year lifestyle intervention program.

METHODS

Parameters were assessed at baseline and at 1 year. Three groups (G) were defined according the International Obesity Task Force reference values, G1: normal weight / G2: overweight / G3: obese. The lifestyle intervention included dietary counseling, regular physical activity and family support.

RESULTS

A total of 120 children (G1: n = 44, G2: n = 39, G3: n = 37), aged 11- 15 years and 59 % girls were enrolled. Obese children showed significant lower HDL-C, adiponectin and ghrelin concentrations, higher triglycerides, fasting blood glucose, insulin and leptin levels and also higher frequencies of abdominal obesity (G1: 2.3 %, G2: 28.2 %, G3: 73 %) and insulin resistance (GI: 39 %, G2: 72 %, G3: 89 %) than the other groups. In the overall sample, the linear regressions exploring the associations of ghrelin, adiponectin and leptin with age, gender, BMI z-score, HOMA-IR and tanner stage as independent variables showed strong associations of leptin levels with weight status and insulin resistance at baseline. The models accounted for 58 % of variability in leptin levels compared with 26 and 15 % for adiponectin and ghrelin levels respectively. In 83 children who completed the program, significant decreases in BMI z-score in overweight and obese children were noted. Leptin levels decreased significantly only in the obese group whereas adiponectin concentrations increased significantly in the three groups, In obese children, a significant correlation was found between changes in BMI Z-score, and changes in leptin levels (r = 0.39; P = 0.049) but not with changes in adiponectin levels.

CONCLUSIONS

Abdominal obesity and insulin resistance were highly prevalent in obese children highlighting their risk of metabolic complications in adulthood. A 1-year long lifestyle intervention was associated with improvement in BMI z-score and metabolic parameters.

Sex-Specific and Estrous Cycle-Dependent Antidepressant-Like Effects and Hippocampal Akt Signaling of Leptin

Sex differences in the incidence of depression and antidepressant treatment responses are well documented. Depression is twice as common in women as in men. Recent studies indicate that low levels of leptin, an adipocyte-derived hormone, are associated with increased symptoms of depression in women. Leptin has been shown to produce antidepressant-like effects in male rodents. In the present study, we examined sex differences and estrous cycle variations in antidepressant-like responses to leptin. Leptin administration significantly reduced immobility, a putative measure of behavioral despair, in the forced swim test in intact female mice in the proestrus phase but not in the diestrus phase of the estrous cycle. Moreover, leptin administration stimulated Akt phosphorylation in the hippocampus of female mice in proestrus but not in diestrus, in correlation with its differential behavioral effects in these two phases of the cycle. Leptin-induced behavioral responses and stimulation of hippocampal Akt phosphorylation in female mice were abolished by ovariectomy. By contrast, the antidepressant-like effect of leptin in male mice was not affected by gonadectomy (castration). Pretreatment with 17β-estradiol restored sensitivity to the effects of leptin on behavior and hippocampal Akt phosphorylation in ovariectomized female mice. These results suggest leptin regulates depression-like behavior and hippocampal Akt signaling in a sex-specific and estrous cycle-dependent manner.

Individual Differences in Cue-Induced Motivation and Striatal Systems in Rats Susceptible to Diet-Induced Obesity

Pavlovian cues associated with junk-foods (caloric, highly sweet, and/or fatty foods), like the smell of brownies, can elicit craving to eat and increase the amount of food consumed. People who are more susceptible to these motivational effects of food cues may have a higher risk for becoming obese. Further, overconsumption of junk-foods leading to the development of obesity may itself heighten attraction to food cues. Here, we used a model of individual susceptibility to junk-foods diet-induced obesity to determine whether there are pre-existing and/or diet-induced increases in attraction to and motivation for sucrose-paired cues (ie, incentive salience or 'wanting'). We also assessed diet- vs obesity-associated alterations in mesolimbic function and receptor expression. We found that rats susceptible to diet-induced obesity displayed heightened conditioned approach prior to the development of obesity. In addition, after junk-food diet exposure, those rats that developed obesity also showed increased willingness to gain access to a sucrose cue. Heightened 'wanting' was not due to individual differences in the hedonic impact ('liking') of sucrose. Neurobiologically, Mu opioid receptor mRNA expression was lower in striatal 'hot-spots' that generate eating or hedonic impact only in those rats that became obese. In contrast, prolonged exposure to junk-food resulted in cross-sensitization to amphetamine-induced locomotion and downregulation of striatal D2R mRNA regardless of the development of obesity. Together these data shed light on individual differences in behavioral and neurobiological consequences of exposure to junk-food diets and the potential contribution of incentive sensitization in susceptible individuals to greater food cue-triggered motivation.

Gender differences in the association of sleep apnea and inflammation

Over the last 15years, many studies have established an association of sleep apnea with inflammation and metabolic aberrations. However, no controlled studies have examined potential gender effects in this association. We recruited 120 middle-aged, predominantly non-obese mild-to-moderate sleep apneics and controls (62 males, 58 females). All participants underwent a clinical history, physical examination, and 1-night 8-h polysomnography recording and provided a single fasting blood sample for assessment of interleukin-6 (IL-6), tumor necrosis factor receptor 1 (TNFR1), C-reactive protein (CRP), leptin, and adiponectin levels. Among non-sleep apneics, females had higher levels of TNFR1 (p=0.01), CRP (p=0.005), leptin (p<0.001), and adiponectin (p<0.001) compared to males, independent of age and body mass index. When analyzed separately by gender, sleep apneic men had elevated TNFR1 (p=0.04), CRP (p=0.06) and IL-6 (p=0.11) relative to control men; in sleep apneic females, only CRP was elevated (p=0.04). Furthermore, CRP was associated with apnea severity in a dose-response manner (p-linear=0.04 in both genders) and was independently associated with comorbid hypertension in apnea (p-linear=0.005 for women; p-linear=0.09 for men). In conclusion, although women have naturally higher levels of inflammatory and metabolic markers than men, sleep apneic men appear to have a more severe inflammatory profile compared to women. Our findings suggest that these markers should be analyzed and interpreted separately in men and women, and that a single measure of plasma CRP appears to be a clinically-useful marker of apnea severity and comorbid cardiovascular morbidity.

Mediatory effect of circulating vaspin on resting metabolic rate in obese individuals

BACKGROUND/OBJECTIVE

Vaspin is a recently identified adipokine related to obesity and insulin sensitivity. The precise mechanism of vaspin in the body is not well known, and its function in resting metabolic rate (RMR) is even less understood. Therefore, the main aim of this study was to investigate the effect of circulating vaspin on RMR in obese people.

MATERIALS AND METHODS

A total of 222 obese participants were included in the current comparative cross-sectional study. Body composition was measured using body composition analyzer. RMR was measured by means of indirect calorimetry. For the measurement of vaspin serum concentrations, an enzyme-linked immunosorbent assay was used. Dietary intake was assessed using 3-day 24-h dietary recall.

RESULTS

Between low and high circulating vaspin groups, there was significant difference for sex (P = 0.03), fat percent (P = 0.008), RMR per weight (P < 0.001), and RMR per fat free mass (FFM) (P = 0.007). However, there was no statistical difference between the groups in dietary intake after adjustment for energy intake (P > 0.05). Furthermore, individuals with higher level of RMR had higher vaspin concentration. Weight, visceral fat, FFM, and fat mass had significant effect on increasing RMR (P < 0.05) but after adding vaspin as a covariate in the general linear model; visceral fat (P = 0.078) and fat mass (P = 0.339) missed their effectiveness.

CONCLUSION

Circulating vaspin level is higher in women than in men in obese individuals. Moreover, it was found that vaspin had mediator effect between visceral fat and fat mass associations with RMR in obese participants.

Adipocytokines, C-reactive protein, and cardiovascular disease: a population-based prospective study

BACKGROUND

Being overweight or obese is associated with a greater risk of coronary heart disease and stroke compared with normal weight. The role of the specific adipose tissue-derived substances, called adipocytokines, in overweight- and obesity-related cardiovascular disease (CVD) is still unclear.

OBJECTIVE

To investigate the associations of three adipose tissue-derived substances: adiponectin, leptin, and interleukin-6 with incident CVD in a longitudinal population-based study, including extensive adjustments for traditional and metabolic risk factors closely associated with overweight and obesity. C-reactive protein (CRP) was used as a proxy for interleukin-6.

METHODS

Prospective population-based study of 6.502 participants, 51.9% women, aged 30-60 years, free of CVD at baseline, with a mean follow-up time of 11.4 years, equivalent to 74,123 person-years of follow-up. As outcome, we defined a composite outcome comprising of the first event of fatal and nonfatal coronary heart disease and fatal and nonfatal stroke.

RESULTS

During the follow-up period, 453 composite CV outcomes occurred among participants with complete datasets. In models, including gender, age, smoking status, systolic blood pressure, treatment for hypertension, diabetes, body mass index (BMI), total cholesterol, high-density-lipoprotein cholesterol, homeostasis model assessment of insulin resistance, estimated glomerular filtration rate, adiponectin, leptin, and CRP, neither adiponectin (hazard ratio [HR] with 95% confidence interval [CI]: 0.97 [0.87-1.08] per SD increase, P = 0.60) nor leptin (0.97 [0.85-1.12] per SD increase, P = 0.70) predicted the composite outcome, whereas CRP was significantly associated with the composite outcome (1.19 [1.07-1.35] per SD increase, P = 0.002). Furthermore, in mediation analysis, adjusted for age and sex, CRP decreased the BMI-associated CV risk by 43% (95%CI 29-72).

CONCLUSIONS

In this study, neither adiponectin nor leptin were independently associated with CVD, raising questions over their role in CVD. The finding that CRP was significantly associated with an increased risk of CVD and decreased the BMI-associated CVD risk substantially, could imply that interleukin-6-related pathways may play a role in mediating overweight- and obesity-related CVD.

Early leptin intervention reverses perturbed energy balance regulating hypothalamic neuropeptides in the pre- and postnatal calorie-restricted female rat offspring

Pre- and postnatal calorie restriction is associated with postnatal growth restriction, reduced circulating leptin concentrations, and perturbed energy balance. Hypothalamic regulation of energy balance demonstrates enhanced orexigenic (NPY, AgRP) and diminished anorexigenic (POMC, CART) neuropeptide expression (PN21), setting the stage for subsequent development of obesity in female Sprague-Dawley rats. Leptin replenishment during the early postnatal period (PN2-PN8) led to reversal of the hypothalamic orexigenic:anorexigenic neuropeptide ratio at PN21 by reducing only the orexigenic (NPY, AgRP), without affecting the anorexigenic (POMC, CART) neuropeptide expression. This hypothalamic effect was mediated via enhanced leptin receptor (ObRb) signaling that involved increased pSTAT3/STAT3 but reduced PTP1B. This was further confirmed by an increase in body weight at PN21 in response to intracerebroventricular administration of antisense ObRb oligonucleotides (PN2-PN8). The change in the hypothalamic neuropeptide balance in response to leptin administration was associated with increased oxygen consumption, carbon dioxide production, and physical activity, which resulted in increased milk intake (PN14) with no change in body weight. This is in contrast to the reduction in milk intake with no effect on energy expenditure and physical activity observed in controls. We conclude that pre- and postnatal calorie restriction perturbs hypothalamic neuropeptide regulation of energy balance, setting the stage for hyperphagia and reduced energy expenditure, hallmarks of obesity. Leptin in turn reverses this phenotype by increasing hypothalamic ObRb signaling (sensitivity) and affecting only the orexigenic arm of the neuropeptide balance.

Roles of physical activity and cardiorespiratory fitness on sex difference in insulin resistance in late elementary years

PURPOSE

Little is known about the potential role of lifestyle factors in sex differences in insulin resistance in late elementary school children.

METHODS

In this cross-sectional study, we compared sex differences in Tanner scales, body fat, physical activity (PA) and fitness, and insulin resistance markers in elementary school children (boys, n = 69 and girls, n = 81) aged 12-13 years. Body composition was assessed with a standardized protocol. Cardiorespiratory fitness was measured as oxygen consumption during an incremental treadmill exercise. Fasting blood samples were collected for blood chemistry assays including lipids, glucose, insulin and homeostasis model assessment for insulin resistance (HOMA-IR), leptin, and adiponectin. Daily PA was measured with an accelerometer for 7 consecutive days, and they were classified as low-, moderate-, and vigorous-PA. Independent t-tests were used to compare mean differences in the measured variables between boys and girls. There were significant sex differences in Tanner scales, body mass index, percent body fat, and waist circumference (WC).

RESULTS

Girls had significantly higher values in Tanner scales (p < 0.001) and percent body fat (p < 0.001) than boys. Boys had significantly higher values in body mass index (p = 0.019) and waist circumference (p < 0.001) than girls. Boys also had significantly higher values in VO2max (p < 0.001) and low (p < 0.001), moderate (p < 0.001), and vigorous (p < 0.001) PAs. With respect to metabolic risk factors, girls had significantly higher serum levels of triglycerides (p = 0.005), insulin (p < 0.001), and HOMA-IR (p < 0.001) and significantly lower high-density lipoprotein cholesterol (p = 0.015) than boys.

CONCLUSION

In summary, the current findings of the study showed that the increased risk for insulin resistance in girls over boys is associated with higher Tanner scale and percent body fat in conjunction with poor cardiorespiratory fitness and physical inactivity, suggesting that exercise intervention to promote physical activity and fitness is imperative for general health promotion of school children, with a special focus on girls.

Leptin regulates CD16 expression on human monocytes in a sex-specific manner

Fat mass is linked mechanistically to the cardiovascular system through leptin, a 16 kDa protein produced primarily by adipocytes. In addition to increasing blood pressure via hypothalamic‐sympathetic pathways, leptin stimulates monocyte migration, cytokine secretion, and other functions that contribute to atherosclerotic plaque development. These functions are also characteristics of CD16‐positive monocytes that have been implicated in the clinical progression of atherosclerosis. This investigation sought to determine if leptin promoted the development of such CD16‐positive monocytes. Cells from 45 healthy men and women with age ranging from 20 to 59 years were analyzed. Circulating numbers of CD14⁺⁺16⁺⁺ monocytes, which are primary producers of TNFα, were positively related to plasma leptin concentrations (P < 0.0001), with a stronger correlation in men (P < 0.05 for leptin × sex interaction). In vitro, recombinant human leptin induced CD16 expression in a dose‐related manner (P = 0.02), with a stronger influence on monocytes from men (P = 0.03 for leptin × sex interaction). There were no sex‐related differences in total leptin receptor expression on any monocyte subtypes, relative expression of long versus short isoforms of the receptor, or soluble leptin receptor concentrations in the plasma. The number of circulating CD14⁺16⁺⁺ monocytes, which preferentially migrate into nascent plaques, was positively related to systolic blood pressure (R = 0.56, P = 0.0008) and intima‐media thickness (R = 0.37, P = 0.03), and negatively related to carotid compliance (R = −0.39, P = 0.02). These observations indicate that leptin promotes the development of CD16‐positive monocyte populations in a sex‐specific manner and that these subpopulations are associated with diminished vascular function.

e12177

Recombinant leptin induced CD16 expression on human monocytes in vitro in a dose‐ and sex‐specific manner. In vivo, CD16 expression on human monocytes correlated with plasma leptin concentrations in a sex‐specific manner. Blood pressure, carotid intima‐media thickness and carotid compliance were related to the number of circulating CD16‐positive monocytes.

Body mass index, weight change, and clinical progression in mild cognitive impairment and Alzheimer disease

The speed and severity of clinical progression after Alzheimer disease (AD) diagnosis varies and depends on multiple factors, most not well elucidated. We assessed whether body mass index (BMI) and 1-year weight change (WC) are associated with clinical progression in amnestic mild cognitive impairment (aMCI) and early-stage AD. Longitudinal data comprising 2268 aMCI and 1506 AD participants in the National Alzheimer's Coordinating Center's Uniform Data Set were used to examine nuances of clinical progression by BMI and WC, as well as potential variations in associations by age, sex, BMI (WC model), or apolipoprotein E genotype. In aMCI, high BMI (vs. moderate BMI) was associated with slower progression; weight loss (vs. no WC) was associated with faster progression. In AD, no significant differences were observed in clinical progression by BMI or WC. The association between BMI and clinical progression varied significantly by apolipoprotein E genotype in AD, and the association between WC and clinical progression varied significantly by sex and BMI in aMCI. Baseline BMI and 1-year WC in late life may serve as early prognostic indicators in aMCI and early-stage AD. If replicated, these results may help in counseling patients on anticipated clinical progression and suggest windows of opportunity for intervention.

Leptin and smoking cessation: secondary analyses of a randomized controlled trial assessing physical activity as an aid for smoking cessation

Background

Smokers have a lower body weight compared to non-smokers. Smoking cessation is associated with weight gain in most cases. A hormonal mechanism of action might be implicated in weight variations related to smoking, and leptin might be implicated. We made secondary analyses of an RCT, with a hypothesis-free exploratory approach to study the dynamic of leptin following smoking cessation.

Methods

We measured serum leptin levels among 271 sedentary smokers willing to quit who participated in a randomized controlled trial assessing a 9-week moderate-intensity physical activity intervention as an aid for smoking cessation. We adjusted leptin for body fat levels. We performed linear regressions to test for an association between leptin levels and the study group over time.

Results

One year after smoking cessation, the mean serum leptin change was +3.23 mg/l (SD 4.89) in the control group and +1.25 mg/l (SD 4.86) in the intervention group (p of the difference < 0.05). When adjusted for body fat levels, leptin was higher in the control group than in the intervention group (p of the difference < 0.01). The mean weight gain was +2.91 (SD 6.66) Kg in the intervention and +3.33 (SD 4.47) Kg in the control groups, respectively (p not significant).

Conclusions

Serum leptin levels significantly increased after smoking cessation, in spite of substantial weight gain. The leptin dynamic might be different in chronic tobacco users who quit smoking, and physical activity might impact the dynamic of leptin in such a situation.

Clinical trial registration number

NCT00521391

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2458-14-911) contains supplementary material, which is available to authorized users.

The association of leptin with dyslipidemia, arterial hypertension and obesity in Kyrgyz (Central Asian nation) population

BACKGROUND

Leptin, an adipocytokine produced by adipose tissue, along with the traditional cardiometabolic risk factors, contributes to the development of cardiovascular complications. At the same time, ethnic features of adipocytokines have been insufficiently investigated, especially among Asians, who have an increased risk of cardiovascular complications compared with Europeans. Aim of study was to investigate the relationship between leptin levels and age, gender, anthropometric parameters, lipid parameters, arterial hypertension (AH), and obesity in the adult population of ethnic Kyrgyz people living in Central Asia.

RESULTS

In total, 322 ethnic Kyrgyz (145 men, 177 women) aged ≥ 30 years were studied. Waist and hip circumference, body mass index, blood glucose, lipids, leptin, and homeostatic model assessment were measured. Patients in the upper quartile of leptin levels had high values of BMI, WC, systolic and diastolic blood pressure, glucose, and HOMA index compared with patients with lower leptin levels. The prevalence of metabolic syndrome and AH increased with higher levels of leptin. Leptin positively correlated with BMI, WC, triglycerides, and glucose concentrations in patients of both sexes. According to the multivariate logistic regression analysis, elevated leptin levels increased by 30 times the risk of obesity in men, regardless of the presence of type 2 diabetes, and 17.7 times in women.

CONCLUSION

Leptin is associated with general and abdominal obesity, dyslipidemia, and insulin resistance in Kyrgyz patients.