Effects of supplementation with curcumin on serum adipokine concentrations: A randomized controlled trial. Effect of vitamin D supplementation on selected inflammatory biomarkers in older adults: a secondary analysis of data from a randomised, placebo-controlled trial. Elevated levels of interleukin 6 are reduced in serum and subcutaneous adipose tissue of obese women after weight loss. Vitamin D deficiency, serum leptin and osteoprotegerin levels in older diabetic patients: an input to new research avenues Consumption of vitamin D-fortified yogurt drink increased leptin and ghrelin levels but reduced leptin to ghrelin ratio in type 2 diabetes patients: a single blind randomized controlled trial Longitudinal Analysis of Maternal Serum Leptin Levels during Pregnancy, at Birth and Up To Six Weeks after Birth: Relation to Body Mass Index, Skinfolds, Sex Steroids and Umbilical Cord Blood Leptin Levels The Effect of Vitamin D Supplementation on Adiposity, Blood Glycated Hemoglobin, Serum Leptin and Tumor Necrosis Factor-α in Type 2 Diabetic Patients Increased leptin levels in serum and peritoneal fluid of patients with pelvic endometriosis. Early Regression of Carotid Intima-Media Thickness after Bariatric Surgery and Its Relation to Serum Leptin Reduction Effect of high doses of vitamin D on arterial properties, adiponectin, leptin and glucose homeostasis in type 2 diabetic patients. Effects of zinc supplementation on serum zinc and leptin levels, BMI, and body composition in hemodialysis patients. Atypical Antipsychotic Usage-Related Higher Serum Leptin Levels and Disabled Lipid Profiles in Euthymic Bipolar Patients Airway inflammation in obstructive sleep apnea: is leptin the missing link? Role of serum leptin, insulin, and estrogen levels as potential mediators of the relationship between fat mass and bone mineral density in men versus women. Overview of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers
OBJECTIVE Previous experimental studies have suggested curcumin as a safe phytochemical that can improve insulin resistance through effects on adiponectin and leptin . This study aim ed to investigate the effect of curcumin on circulating adiponectin and leptin concentrations in patients with metabolic syndrome . METHODS In this pilot , r and omized , double-blind , placebo-controlled trial , subjects who met the criteria of metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III criteria were r and omly assigned to curcumin ( n = 59 ; 1000 mg/d ) or a placebo ( n = 58 ) for 8 wk . Serum adiponectin and leptin concentrations were determined before and after intervention . The pooled effect size for the impact of curcumin supplementation on serum adiponectin and leptin levels was also estimated using r and om-effects meta analysis . RESULTS Eight-week supplementation with curcumin was associated with a significant increase in serum adiponectin levels ( P < 0.001 ) and a reduction in serum leptin concentrations ( P < 0.001 ) . Serum leptin : adiponectin ratio was also improved by curcumin ( P < 0.001 ) . These beneficial effects of curcumin remained significant after adjustment for changes in serum lipids and glucose concentrations and baseline differences in body mass index and serum levels of glucose and glycated hemoglobin as potential confounders of treatment response . Meta analysis suggested that curcumin supplementation can increase adiponectin levels by 76.78 % ( 95 % CI : 6.14 - 147.42 ; P = 0.0330 ) , and reduce leptin by 26.49 % ( 95 % CI : -70.44 to 17.46 ) , however this latter effect size did not reach statistical significance ( P = 0.238 ) . CONCLUSIONS Curcumin can improve serum levels of adiponectin and leptin in patients with metabolic syndrome . This trial was registered at the UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr/ ) under Trial No. UMIN000018339 Observational studies have suggested that 25-hydroxyvitamin D ( 25(OH)D ) levels are associated with inflammatory markers . Most trials reporting significant associations between vitamin D intake and inflammatory markers used specific patient groups . Thus , we aim ed to determine the effect of supplementary vitamin D using secondary data from a population -based , r and omised , placebo-controlled , double-blind trial ( Pilot D-Health trial 2010/0423 ) . Participants were 60- to 84-year-old residents of one of the four eastern states of Australia . They were r and omly selected from the electoral roll and were r and omised to one of three trial arms : placebo ( n 214 ) , 750 μg ( n 215 ) or 1500 μg ( n 215 ) vitamin D3 , each taken once per month for 12 months . Post-intervention blood sample s for the analysis of C-reactive protein ( CRP ) , IL-6 , IL-10 , leptin and adiponectin levels were available for 613 participants . Associations between intervention group and biomarker levels were evaluated using quantile regression . There were no statistically significant differences in distributions of CRP , leptin , adiponectin , leptin : adiponectin ratio or IL-10 levels between the placebo group and either supplemented group . The 75th percentile IL-6 level was 2·8 pg/ml higher ( 95 % CI 0·4 , 5·8 pg/ml ) in the 1500 μg group than in the placebo group ( 75th percentiles:11·0 v. 8·2 pg/ml ) , with a somewhat smaller , non-significant difference in 75th percentiles between the 750 μg and placebo groups . Despite large differences in serum 25(OH)D levels between the three groups after 12 months of supplementation , we found little evidence of an effect of vitamin D supplementation on cytokine or adipokine levels , with the possible exception of IL-6 The aim of this study was to investigate the potential role of adipose cytokines in the obesity-associated insulin resistance . To that end , we compared : 1 ) serum concentrations of interleukin 6 ( IL-6 ) , tumor necrosis factor alpha ( TNFalpha ) , and leptin in eight healthy lean control females and in and roid obese female without ( n = 14 ) and with ( n = 7 ) type 2 diabetes ; and 2 ) the levels of these cytokines both in serum and in sc adipose tissue in the 14 obese nondiabetic women before and after 3 weeks of a very low-calorie diet ( VLCD ) .  As compared with lean controls , obese nondiabetic and diabetic patients were more insulin resistant and presented increased values for leptin , IL-6 , TNFalpha , and C-reactive protein . In the whole group , IL-6 values were more closely related to the parameters evaluating insulin resistance than leptin or TNFalpha values .  VLCD result ed in weight loss and decreased body fat mass ( approximately 3 kg ) . Insulin sensitivity was improved with no significant change in both serum and adipose tissue TNFalpha levels . In contrast , VLCD induced significant decreases in IL-6 and leptin levels in both adipose tissue and serum . These results suggest that , as for leptin , circulating IL-6 concentrations reflect , at least in part , adipose tissue production . The reduced production and serum concentrations after weight loss could play a role in the improved sensitivity to insulin observed in these patients The aim of this study was to assess the effects of single oral bolus of 300,000 IU Vitamin D3 on serum levels and on bone and metabolic parameters in diabetic patients . This study is a Phase IV , r and omized , double-blind , placebo-controlled , monocenter clinical trial . Thirty patients , 60 years or older , with type 2 diabetes mellitus , and diabetic foot complications , were enrolled and monitored for 24 weeks : 14 were treated with Vitamin D3 and 16 with placebo . Parameters including glucose , adiponectin , leptin , osteoprotegerin ( OPG ) , 25-hydroxyvitamin D [ 25(OH)D ] , beta-CrossLaps , osteocalcin , bone-specific isoenzyme of alkaline phosphatase , tumor necrosis factor-α and parathyroid hormone were measured at screening and baseline and 12 and 24 weeks after treatment . Analysis of covariance was used to compare treatment groups . Analysis of the data detected a significant increase in 25(OH)D serum levels both at 12 and 24 weeks with respect to baseline values only in the treated patients . Significant variations with respect to baseline values were noted in OPG ( P = 0.0085 ) and in leptin ( P = 0.0442 ) levels : these were lower in the placebo group at week 24 but higher in the treated group . Vitamin D3 supplementation significantly increased serum leptin and OPG levels . Further , large-scale clinical trials are warranted to confirm these results Purpose This study aim ed to evaluate the effect of daily consumption of vitamin D-fortified yogurt drink ( doogh ) in comparison with plain doogh on appetite-regulating hormones including leptin and ghrelin in type 2 diabetes ( T2D ) patients . Methods In a single blind r and omized clinical trial , subjects with T2D were r and omly allocated to one of the two groups and received either vitamin D3-fortified doogh ( FD ; containing 170 mg calcium and 500 IU/250 mL , n2 = 50 ) or plain doogh ( PD ; containing 170 mg calcium and no vitamin D/250 mL , n1 = 50 ) twice a day for 12 weeks . Leptin and ghrelin were evaluated at the beginning and after 12 weeks of intervention . Results The intervention result ed in a significant improvement of circulating 25(OH)D , fasting glucose , Quantitative Insulin Check Index ( QUICKI ) , hs-CRP , in FD compared with PD group . A significant rise in both serum leptin ( + 1.3 ± 7.2 mg/L ; p = 0.013 ) and ghrelin ( 10.1 ± 26.1 ng/L ; p = 0.012 ) was observed in FD group . A between-group difference for ghrelin changes ( p = 0.029 ) remained significant after adjusting for changes QUICKI ( p = 0.039 ) , body mass index ( p = 0.034 ) and hs-CRP ( p = 0.022 ) . Despite an increase in both leptin and ghrelin , leptin to ghrelin ( L/G ) ratio actually decreased in FD . Changes of L/G ratio showed a significant between-group difference ( p = 0.036 ) , which remained significant even after adjusting for changes of hs-CRP ( p = 0.028 ) and fat mass ( p = 0.047 ) but disappeared after adjusting for changes of QUICKI ( p = 0.42 ) . Conclusions Daily intake of vitamin D-fortified doogh may increase circulating leptin and ghrelin but L/G ratio may actually decrease . Our results suggest that improving vitamin D may result in an improvement in insulin sensitivity which may finally regulate beneficially appetite hormones . Further studies with adequate power are needed to confirm the results Leptin is an important regulator of body fat mass and energy expenditure during adult life . The mechanisms by which maternal and fetal weight are regulated during pregnancy are poorly understood . In order to gain more insight into a potential role of leptin during gestation , a prospect i ve , longitudinal study was carried out to measure leptin concentrations in maternal serum of 29 healthy women during pregnancy up to 6 weeks after birth and also in umbilical cord blood of their newborns .  Leptin concentrations were measured using a specific RIA . In addition , estradiol , testosterone , and sex hormone binding globulin were determined using commercially available RIAs . The mothers ’ skinfolds were determined at four sites using a Holtain caliper . Leptin levels increased continuously during pregnancy and reached 25.8 ± 14.7 ng/ml at 38–40 weeks . At birth , leptin concentrations were 23.5 ± 15.4 ng/ml . Three days after delivery a significant decrease of leptin levels to 10.6 ± 6.0 ng/ml was observed . Six weeks after birth the leptin concentration in maternal serum was 13.8 ± 8.6 ng/ml . At birth , maternal serum levels were significantly higher than levels in cord blood and did not correlate with leptin levels in cord blood or neonatal weight . Furthermore , leptin levels did not correlate with maternal sex steroids and sex hormone binding globulin levels . At 6–8 weeks of pregnancy , maternal leptin serum levels correlated significantly with BMI ( r = 0.81 ) . The correlation coefficients ( leptin vs. BMI ) dropped with increasing gestational age and at birth only a poor correlation persisted ( r = 0.50 ) . Six weeks after birth there was again a high correlation between leptin levels in maternal serum and BMI ( r = 0.76 ) . Subscapular skinfold thickness was correlated to leptin concentrations in maternal serum during the whole period of the investigation . In conclusion , maternal leptin levels continuously increased from 6–8 weeks up to 38–40 weeks of pregnancy . Maternal leptin levels decreased dramatically after birth . Six weeks after delivery , leptin levels were comparable to the values measured at the beginning of pregnancy . We hypothesize that leptin might play an important role during pregnancy and fetal development Background : Since tumor necrosis factor-α ( TNF-α ) could be one of the risk factors at the development of diabetes complications ; as well as serum leptin deficiency is related to increased susceptibility to infections in diabetic patients , they are potential indices from the preventive medicine viewpoint . This study was conducted to represent the effect of supplemental vitamin D3 on serum leptin , TNF-α and adiposity in type 2 diabetic patients . Methods : In this r and omized double-blind placebo-controlled trial , study sample was selected through type 2 diabetic patients ( n = 51 ) . A total of 26 patients were orally supplemented by vitamin D3 ( 400 IU/d ) ( vitamin D group ) and 25 patients by placebo ( placebo group ) for 14 weeks . The blood glycated hemoglobin ( HbA1c ) and the serum ionized Ca , leptin , TNF-α , and serum 25-hydroxyvitamin D ( 25[OH ] D ) were measured at the two groups in the baseline and postintervention stages . Results : It was shown that despite of theplacebo group , serum 25(OH ) D and serum leptin was significantly increased ( P = 0.001 and P = 0.002 , respectively ) , while serum TNF-α was decreased significantly ( P = 0.001 ) in vitamin D group . The remaining parameters , including body fat mass and HbA1c had no alterations between baseline and postintervention stages in vitamin D group . Conclusions : This study may advocate vitamin D supplementation among type 2 diabetic patients due to its beneficial effects on prevention of diabetes complications Pelvic endometriosis is an immune-related chronic inflammatory disease , characterized by ectopic implants of endometrium in the peritoneal cavity and associated with increased secretion of proinflammatory cytokines and neoangiogenesis . Leptin , the adipocyte-derived hormone , has been shown to have a role in food intake , basal metabolism , and reproductive function . Leptin levels are dynamically regulated , being elevated by inflammatory mediators and reduced by starvation . Leptin itself can influence the proinflammatory immune responses of CD4 + T lymphocytes , and reports have also shown this hormone to be an angiogenic factor in vitro and in vivo . We investigated whether  leptin concentrations in serum and peritoneal fluid ( PF ) differed between 13 patients with different stages of endometriosis and 15 age- and body mass index-matched controls . We found a statistically significant ( P < 0.05 ) increase in leptin levels in serum ( 30.3 + /- 14.8 ng/mL ) and PF ( 35.9 + /- 17.4 ng/mL ) of patients with endometriosis , compared with our control population ( serum , 15.6 + /- 8.4 ; PF , 17.5 + /- 7.2 ng/mL ) . Regression equations , relating leptin to body mass index , were also significantly different in endometriosis patients , compared with controls . Higher levels of leptin were observed in the earlier stages of endometriosis than advanced-stage disease . These data suggest that the proinflammatory and neoangiogenic actions of leptin may contribute to the pathogenesis of endometriosis Purpose Bariatric surgery ( BS ) promotes carotid intima-media thickness ( C-IMT ) regression as early as 6 months post-surgery . To verify whether C-IMT regression occurs even earlier , we aim ed at the effect of Roux-en-Y gastric bypass ( RYGBP ) and biliopancreatic diversion ( BPD ) on C-IMT 1–2 months and 12 months post-surgery . Subjects/ Methods Prospect i ve trial . BS was performed on 109 patients either with ( RYGBP = 42 ; BDP = 40 ) or without type 2 diabetes ( RYGBP = 27 ) . Healthy volunteers served as control group . Follow-up : baseline , 1–2 months , 12 months post-surgery . Endpoints : changes ( ∆ ) in C-IMT , weight , body mass index , fat mass , waist and neck circumferences , blood pressure , HbA1c , glucose , insulin , insulin sensitivity [ HOMA-IR ; OGIS , from meal tolerance test ] , lipids , C-reactive protein , leptin , adiponectin , MCP-1 . Results All surgery subgroups had similar levels of ∆-C-IMT . C-IMT in the pooled surgery group reduced from [ mean ( 95 % confidence interval ) ] 0.81 ( 0.77–0.84 ) mm to 0.66 ( 0.63–0.69 ) mm , p < 0.001 [ −17.1 ( −20.4 to −13.8)% ] at 1–2 months , and to 0.63 ( 0.59–0.66 ) mm , p < 0.001 [ −21.8 ( −25.3 to −18.4)% ] at 12 months post-surgery . ∆-C-IMT 1–2 months and 12 months post-surgery correlated to baseline C-IMT , and with ∆-leptin at 1–2 months , but not at 12 months post-surgery . In linear regression analysis , ∆-leptin and baseline C-IMT were predictors of ∆-C-IMT 1–2 months post-surgery . Conclusions A remarkable C-IMT regression occurred as early as 1–2 months after BS in obese patients either with or without type 2 diabetes , which was associated to the early reduction in leptin , ( at least partially ) independent of weight loss . Whether this is a causative or correlative association needs further investigation BACKGROUND & AIMS Vitamin D supplementation has the potential to alleviate the cardiovascular damage in diabetic patients . The present study was design ed to evaluate long term impact of high doses of vitamin D on arterial properties , glucose homeostasis , adiponectin and leptin in patients with type 2 diabetes mellitus . METHODS AND RESULTS In r and omized , placebo-controlled study 47 diabetic patients were assigned into two groups : Group 1 received oral daily supplementation with vitamin D at a dose of 1000 U/day for 12 months . Group 2 received matching placebo capsules . Blood sampling for metabolic parameters , including fasting glucose , lipid profile , HbA1C , insulin , hs-CRP , 25 OH Vit D , adiponectin and leptin was performed at baseline and at the end of the study . Insulin resistance was assessed by homeostasis model assessment ( HOMA-IR ) . Central aortic augmentation index ( AI ) was evaluated using SphygmoCor . RESULTS The two groups were similar at baseline in terms of hemodynamic parameters . After 12 months , AI decreased significantly during the treatment period in patients received vitamin D ( p < 0.0001 ) and did not change in placebo group . Glucose homeostasis parameters , leptin as well as leptin adiponectin ratio did not change in both groups . 25 OH Vit D level significantly increased ( p = 0.022 ) and circulating adiponectin marginally increased ( p = 0.065 ) during 12 month treatment period in active treatment and did not change in placebo group . CONCLUSIONS High doses of  vitamin D supplementation in diabetic patients was associated with significant decrease in AI during one year treatment . This beneficial vascular effect was not associated with improvement in glucose homeostasis parameters PROJECT The aim of this study was to determine the effects of zinc supplementation on serum zinc and leptin levels as well as on anthropometric status and some biochemical parameters in hemodialysis ( HD ) patients . PROCEDURE In this r and omized , double-blind , and placebo-controlled trial , sixty HD patients were r and omly divided into groups to receive a daily supplement of 100 mg elemental Zn ( supplemented group ) or placebo ( control group ) for 60 days . Anthropometric measurements were taken using st and ard calibrated instruments . Serum zinc and leptin levels were determined by atomic absorption and ELISA method respectively before and after intervention . RESULTS Zinc supplementation result ed in significant increase in the mean serum zinc level in the experimental group while changes observed in the placebo group were not significant . The mean serum leptin in women part of the experimental group was decreased significantly after supplementation . After adjusting for age , BMI , body fat ( % ) , serum zinc and dietary Zn intake , a negative and significant association was observed between serum zinc and leptin levels in all subjects ( β=-0.33 , P=0.03 ) as a result of Zn supplementation . CONCLUSIONS More studies are needed to clarify the mechanisms by which serum leptin level is influenced as a result of zinc supplementation in HD patients Atypical antipsychotics (AA)-induced  weight gain is associated with increased leptin levels . AA have been increasingly used in the treatment of bipolar disorders . This cross-sectional study aim ed to evaluate the association between serum leptin and lipid profiles considering the drug treatments in euthymic bipolar out patients .  Leptin and lipid profiles were compared , and no differences were noted in leptin , cholesterol , and low-density lipoprotein levels among the patients and controls . Glucose , very-low-density lipoprotein , and triglyceride levels in patients were higher than in controls , while high-density lipoprotein levels were low . Patients were divided into three groups according to their type of drug usage : AA users , AA + mood stabilizer users , and mood stabilizer users .  Each group of patients was compared with a healthy control group for mentioned biochemical parameters . Lipid profiles were disordered by using both AA and mood stabilizers , but higher leptin levels are associated with AA usage . However , leptin does not seem to be responsible for dyslipidemia caused by AA or mood stabilizers in euthymic bipolar patients BACKGROUND Local and systemic inflammation is implicated in the pathophysiology of Obstructive Sleep Apnea ( OSA ) .  Exhaled breath condensate ( EBC ) is a non-invasive sampling method for the lower airways . However , it is important to consider the potential effect of the systemic origin whereas systemic inflammation is significantly elevated . This prospect i ve study was design ed to investigate whether airway inflammation is significantly related to plasma leptin levels in OSA patients . Simultaneously , it was design ed to investigate whether inflammatory variables predict parameters expressing disease severity and finally whether smoking habit affect the above measurements . PATIENTS & METHODS About 45 OSA patients ( mean AHI 40+/-25 , 28 smokers ) and 25 healthy controls ( AHI<5 , 15 smokers ) were studied and underwent overnight diagnostic polysomnography . We measured  pH , 8-isoprostane , TNF-alpha and IL-6 in EBC and leptin in plasma . Plausible associations between leptin and inflammatory parameters were analyzed after adjustment for proper variables . Similar associations between inflammatory variables and parameters of disease severity were also performed . RESULTS An increased level of leptin and respective increase of inflammatory variables was found . No significant association was observed between parameters of EBC and plasma leptin levels . A part of the parameters of disease severity is significantly associated with pH and 8-isoprostane . Smoking did not seem to be a critical confounding factor for evaluation of the above measurements . CONCLUSIONS Increased levels of leptin were not associated with the observed airway  inflammation in OSA . The observed airway inflammation seemed to be independent of smoking habit with limited association with disease severity Although fat mass is related to bone mineral density ( BMD ) , the potential mechanism(s ) of this effect remain to be defined . Thus , we assessed the role of the c and i date hormones , leptin , insulin , and estrogen in mediating fat mass effects on the skeleton . Specifically , we related these hormones and fat mass to BMD at the total hip , mid-lateral spine , and mid-distal radius in a sample of 137 premenopausal women ( age range 21 - 54 years ) , 165 postmenopausal women ( 34 - 93 years ) , and 343 men ( 23 - 90 years ) recruited from the general population .  Fat mass and BMD were significantly related in pre- and postmenopausal women at multiple sites , whereas this relationship was only weakly present in men at the total hip . Serum leptin levels were also significantly related to BMD in the women , but not in the men . Insulin was associated with hip BMD in the women , and bioavailable estradiol ( E2 ) was correlated with BMD at all sites in men and in postmenopausal women . In the women , adjusting for leptin reduced the strength of the association between fat mass and BMD , with further adjustments for insulin or bioavailable E2 having no additional effects . Adjusting for leptin in the men had no consistent effect on the relationship between fat mass and BMD . Collectively , these data suggest that there is a sexual dimorphism in the relationship of fat mass and leptin to BMD , with both being positively associated with BMD in women but not in men . In women , leptin may also mediate at least part of the protective effect of fat mass on the skeleton The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers ( VDPP ) brought together 10 cohorts to conduct a prospect i ve study of the association between vitamin D status , measured as serum concentrations of 25-hydroxyvitamin D ( 25(OH)D ) , and the development of 7 rarer cancer sites : endometrial , esophageal , gastric , kidney , non-Hodgkin lymphoma , ovarian , and pancreatic cancers . The cohorts come from 3 continents , with participants from a wide range of latitude who are racially diverse . Across each cancer site , there was no evidence of a protective association between higher concentrations of 25-hydroxyvitamin D ( > 75 nmol/L ) and cancer outcome . An increased risk at very high levels ( ≥100 nmol/L ) was noted for pancreatic cancer , confirming previous reports . The articles included in this issue detail the overall design and governance of the project , correlates of vitamin D status , and results from the cancer site-specific investigations . The Vitamin D Pooling Project realizes a major goal of consortium efforts , namely , to rigorously test hypotheses for rarer cancer outcomes that may not be adequately addressed in any one prospect i ve cohort study . The results of this study have application for the planning and conduct of intervention trials , especially in determining potential risks
Current evidence indicates that inverse association between leptin level and 25(OH)D concentration was observed in observational studies , which was not demonstrated in intervention studies with high heterogeneity .
We aim ed to investigate the potential association between vitamin D and serum leptin levels by pooling together the results from observational studies and clinical trials .