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Shalaurova I, Connelly MA, Garvey WT, Otvos JD. Lipoprotein insulin resistance index: a lipoprotein particle-derived measure of insulin resistance. Metab Syndr Relat Disord 2014; 12:422-9. [PMID: 24959989 DOI: 10.1089/met.2014.0050] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
UNLABELLED Abstract Background: Lipoprotein particle sizes and concentrations are characteristically altered in patients with insulin resistance (IR) or type 2 diabetes mellitus (T2DM). This study assessed the ability of an IR score, based on nuclear magnetic resonance (NMR)-derived lipoprotein information, to detect IR in otherwise healthy individuals. METHODS Lipoprotein subclass and size information were evaluated for strength of association with IR, as measured by homeostasis model assessment of insulin resistance (HOMA-IR) in the Multi-Ethnic Study of Atherosclerosis (MESA). To increase the likelihood of identifying subjects with IR, six lipoprotein measures were combined into a single algorithm. The resulting assay [Lipoprotein Insulin Resistance Index (LP-IR)] was developed using HOMA-IR in 4972 nondiabetic subjects from MESA and verified independently using glucose disposal rates (GDRs) measured during hyperinsulinemic-euglycemic clamps in 56 insulin-sensitive, 46 insulin-resistant, and 46 untreated subjects with T2DM. RESULTS LP-IR exhibited stronger associations with HOMA-IR (r=0.51) and GDR (r=-0.53) than each of the individual lipoprotein parameters as well as the triglycerides/high-density lipoprotein cholesterol (TGs/HDL-C) ratio (r=0.41 and -0.44, respectively). In MESA, associations between the LP-IR score and HOMA-IR were strong in men (r=0.51), women (r=0.52), European Americans (r=0.58), African Americans (r=0.48), Chinese Americans (r=0.49), and Hispanic Americans (r=0.45). When LP-IR was categorized by HOMA-IR and either body mass index (BMI) or fasting plasma glucose (FPG), subgroups were revealed whose LP-IR scores were high (≥ 50), despite having normal BMIs (<24 kg/m(2)) or FPG (<100 mg/dL). CONCLUSIONS LP-IR scores had strong associations with multiple measures, HOMA-IR, and GDR, the former being more reflective of hepatic and the latter of peripheral insulin sensitivity, and may represent a simple means to identify individuals with IR.
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Amato MC, Pizzolanti G, Torregrossa V, Misiano G, Milano S, Giordano C. Visceral adiposity index (VAI) is predictive of an altered adipokine profile in patients with type 2 diabetes. PLoS One 2014; 9:e91969. [PMID: 24651545 PMCID: PMC3961281 DOI: 10.1371/journal.pone.0091969] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 02/15/2014] [Indexed: 02/08/2023] Open
Abstract
Aims Although there is still no clear definition of “adipose tissue dysfunction” or ATD, the identification of a clinical marker of altered fat distribution and function may provide the needed tools for early identification of a condition of cardiometabolic risk. Our aim was to evaluate the correlations among various anthropometric indices [BMI, Waist Circumference (WC), Hip Circumference (HC), Waist/Hip ratio (WHR), Body Adiposity Index (BAI) and Visceral adiposity Index (VAI)] and several adipocytokines [Visfatin, Resistin, Leptin, Soluble leptin receptors (sOB-R), Adiponectin, Ghrelin, Adipsin, PAI-1, vascular endothelial growth factor (VEGF), Hepatocyte growth factor (HGF) TNF-α, hs-CRP, IL-6, IL-18] in patients with type 2 diabetes (DM2). Materials and Methods Ninety-one DM2 patients (age: 65.25±6.38 years; 42 men and 49 women) in stable treatment for the last six months with metformin in monotherapy (1.5–2 g/day) were cross-sectionally studied. Clinical, anthropometric, and metabolic parameters were evaluated. Serum adipocytokine levels were assayed with Luminex based kits. Results At the Pearson’s correlation, among all the indices investigated, VAI showed a significant correlation with almost all adipocytokines analyzed [Visfatin, Resistin and hsCRP (all p<0.001); Adiponectin, sOb-R, IL-6, IL-18, HGF (all p<0.010); Ghrelin and VEGF (both p<0.05)]. Through a two-step cluster analysis, 55 patients were identified with the most altered adipocytokine profile (patients with ATD). At a ROC analysis, VAI showed the highest C-statistic [0.767 (95% CI 0.66–0.84)] of all the indices. Conclusions Our study suggests that the VAI, among the most common indexes of adiposity assessment, shows the best correlation with the best known adipocytokines and cardiometabolic risk serum markers. Although to date we are still far from clearly identifying an ATD, the VAI would be an easy tool for clearly mirroring a condition of cardiometabolic risk, in the absence of an overt metabolic syndrome.
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Affiliation(s)
- Marco C. Amato
- Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Section of Endocrinology, Diabetology and Metabolism, University of Palermo, Palermo, Italy
| | - Giuseppe Pizzolanti
- Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Section of Endocrinology, Diabetology and Metabolism, University of Palermo, Palermo, Italy
| | - Vittoria Torregrossa
- Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Section of Endocrinology, Diabetology and Metabolism, University of Palermo, Palermo, Italy
| | - Gabriella Misiano
- Dipartimento di Biopatologia e Biotecnologie Mediche e Forensi (Di.Bi.Me.F), Section of Clinical Pathology, University of Palermo, Palermo, Italy
| | - Salvatore Milano
- Dipartimento di Biopatologia e Biotecnologie Mediche e Forensi (Di.Bi.Me.F), Section of Clinical Pathology, University of Palermo, Palermo, Italy
| | - Carla Giordano
- Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Section of Endocrinology, Diabetology and Metabolism, University of Palermo, Palermo, Italy
- * E-mail:
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Mishra S, Harris TB, Hue T, Miljkovic I, Satterfield S, de Rekeneire N, Mehta M, Sahyoun NR. Hyperleptinemia, adiposity, and risk of metabolic syndrome in older adults. J Nutr Metab 2013; 2013:327079. [PMID: 24455217 PMCID: PMC3888758 DOI: 10.1155/2013/327079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 10/03/2013] [Indexed: 11/29/2022] Open
Abstract
Background. Abdominal adiposity and serum leptin increase with age as does risk of metabolic syndrome. This study investigates the prospective association between leptin and metabolic syndrome risk in relation to adiposity and cytokines. Methods. The Health, Aging, and Body Composition study is a prospective cohort of older adults aged 70 to 79 years. Baseline measurements included leptin, cytokines, BMI, total percent fat, and visceral and subcutaneous fat. Multivariate logistic regression was used to determine the association between leptin and metabolic syndrome (defined per NCEP ATP III) incidence after 6 years of follow-up among 1,120 men and women. Results. Leptin predicted metabolic syndrome in men (P for trend = 0.0002) and women (P for trend = 0.0001). In women, risk of metabolic syndrome increased with higher levels of leptin (compared with quintile 1, quintile 2 RR = 3.29, CI = 1.36, 7.95; quintile 3 RR = 3.25, CI = 1.33, 7.93; quintile 4 RR = 5.21, CI = 2.16, 12.56; and quintile 5 RR = 7.97, CI = 3.30, 19.24) after adjusting for potential confounders. Leptin remained independently associated with metabolic syndrome risk after additional adjustment for adiposity, cytokines, and CRP. Among men, this association was no longer significant after controlling for adiposity. Conclusion. Among older women, elevated concentrations of leptin may increase the risk of metabolic syndrome independent of adiposity and cytokines.
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Affiliation(s)
- Suruchi Mishra
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
| | | | - Trisha Hue
- University of California, San Francisco, CA 94107, USA
| | - Iva Miljkovic
- Department of Epidemiology, University of Pittsburg, Pittsburgh, PA 15213, USA
| | | | | | - Mira Mehta
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
| | - Nadine R. Sahyoun
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
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Adiponectin, Leptin, and Resistin in Asthma: Basic Mechanisms through Population Studies. J Allergy (Cairo) 2013; 2013:785835. [PMID: 24288549 PMCID: PMC3832971 DOI: 10.1155/2013/785835] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 09/03/2013] [Accepted: 09/05/2013] [Indexed: 12/12/2022] Open
Abstract
Adipokines, factors produced by adipose tissue, may be proinflammatory (such as leptin and resistin) or anti-inflammatory (such as adiponectin). Effects of these adipokines on the lungs have the potential to evoke or exacerbate asthma. This review summarizes basic mechanistic data through population-based and clinical studies addressing the potential role of adipokines in asthma. Augmenting circulating concentrations of adiponectin attenuates allergic airway inflammation and airway hyperresponsiveness in mice. Murine data is supported by human data that suggest that low serum adiponectin is associated with greater risk for asthma among women and peripubertal girls. Further, higher serum total adiponectin may be associated with lower clinical asthma severity among children and women with asthma. In contrast, exogenous administration of leptin results in augmented allergic airway hyperresponsiveness in mice. Alveolar macrophages obtained from obese asthmatics are uniquely sensitive to leptin in terms of their potential to augment inflammation. Consistent with this basic mechanistic data, epidemiologic studies demonstrate that higher serum leptin is associated with greater asthma prevalence and/or severity and that these associations may be stronger among women, postpubertal girls, and prepubertal boys. The role of adipokines in asthma is still evolving, and it is not currently known whether modulation of adipokines may be helpful in asthma prevention or treatment.
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van der Wijden CL, Delemarre-van der Waal HA, van Mechelen W, van Poppel MNM. The concurrent validity between leptin, BMI and skin folds during pregnancy and the year after. Nutr Diabetes 2013; 3:e86. [PMID: 24018614 PMCID: PMC3789130 DOI: 10.1038/nutd.2013.27] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Revised: 06/27/2013] [Accepted: 07/24/2013] [Indexed: 12/11/2022] Open
Abstract
Background: From a public health perspective it is important to know which of the currently used methods to estimate changes in maternal body fat during pregnancy and the year thereafter is the most adequate. Objectives: To evaluate the concurrent validity between leptin and surrogates of fat measures: body mass index (BMI) and the sum of four skin folds. Design: Data from the New Life(style) intervention study were analysed as a cohort study. Setting: Midwife practices in The Netherlands. Population: Healthy pregnant nulliparous women. Methods: Anthropometric measurements were done and blood was collected at 15, 25 and 35 weeks of pregnancy and at 6, 26 and 52 weeks after delivery. Data were used if at least 4 out of the 6 measurements were available, leaving 87 women in the analyses. Spearman's correlation coefficients between leptin and BMI and between leptin and the sum of skin folds were calculated for each time point and for the changes between the time points. Results: Correlations between leptin and BMI varied from 0.69 to 0.81. Correlations between leptin and the sum of skin folds were comparable, varying between 0.65 and 0.81. Correlations between changes in leptin and changes in BMI and the sum of skin folds, respectively, were much lower compared with cross-sectional correlations. Conclusion: Because of the high correlation among the three methods and because of the overlapping intervals, all methods seem to be equally adequate to estimate changes in maternal body fat during pregnancy and the year thereafter.
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Affiliation(s)
- C L van der Wijden
- 1] Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands [2] Department of Gynaecology, Medisch Centrum Jan van Goyen, Amsterdam, The Netherlands
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Karvonen-Gutierrez CA, Harlow SD, Mancuso P, Jacobson J, Mendes de Leon CF, Nan B. Association of leptin levels with radiographic knee osteoarthritis among a cohort of midlife women. Arthritis Care Res (Hoboken) 2013; 65:936-44. [PMID: 23281224 DOI: 10.1002/acr.21922] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 11/28/2012] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To relate serum leptin levels to prevalent and incident radiographic knee osteoarthritis (OA) and to determine if patterns of change in longitudinal serum leptin measures differ by knee OA status over a 10-year period. METHODS Participants in the Michigan Study of Women's Health Across the Nation underwent bilateral knee radiographs at baseline and followup visits 2, 4, and 11 for ascertainment of knee OA status (Kellgren/Lawrence score ≥2). Serum leptin measures were available from baseline and followup visits 1 and 3-7. RESULTS The baseline prevalence of knee OA (mean age 46 years) was 18%; the 2-year incidence of knee OA at followup visits 2 and 4 was 18% and 14%, respectively. Serum leptin levels were associated with prevalent and incident knee OA. A 5 ng/ml increase in serum leptin level was associated with 38% higher odds of prevalent knee OA (odds ratio [OR] 1.38, 95% confidence interval [95% CI] 1.26-1.52) and 31% greater odds of incident knee OA (OR 1.31, 95% CI 1.21-1.41) after adjustment for covariates, including body mass index residuals. Leptin levels increased with time; on average, serum leptin levels increased by 0.38 ng/ml per year (P = 0.0004). Women with incident knee OA during the 10-year followup period had consistently higher serum leptin levels as compared to women with no knee OA during followup. CONCLUSION Our findings support a metabolic role of obesity in knee OA. A better understanding of the mechanisms by which increased fat mass is associated with joint damage is needed. Management of cardiometabolic dysfunction, including elevated serum leptin levels, may be beneficial in forestalling the onset or progression of knee OA.
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Fuente-Martín E, Argente-Arizón P, Ros P, Argente J, Chowen JA. Sex differences in adipose tissue: It is not only a question of quantity and distribution. Adipocyte 2013; 2:128-34. [PMID: 23991358 PMCID: PMC3756100 DOI: 10.4161/adip.24075] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 02/21/2013] [Accepted: 02/21/2013] [Indexed: 12/12/2022] Open
Abstract
Obesity and its associated secondary complications are active areas of investigation in search of effective treatments. As a result of this intensified research numerous differences between males and females at all levels of metabolic control have come to the forefront. These differences include not only the amount and distribution of adipose tissue, but also differences in its metabolic capacity and functions between the sexes. Here, we review some of the recent advances in our understanding of these dimorphisms and emphasize the fact that these differences between males and females must be taken into consideration in hopes of obtaining successful treatments for both sexes.
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Murphy KT, Schwartz GJ, Nguyen NLT, Mendez JM, Ryu V, Bartness TJ. Leptin-sensitive sensory nerves innervate white fat. Am J Physiol Endocrinol Metab 2013; 304:E1338-47. [PMID: 23612999 PMCID: PMC3680695 DOI: 10.1152/ajpendo.00021.2013] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Leptin, the primary white adipose tissue (WAT) adipokine, is thought to convey lipid reserve information to the brain via the circulation. Because WAT responds to environmental/internal signals in a fat pad-specific (FPS) manner, systemic signals such as leptin would fail to communicate such distinctive information. Saturation of brain leptin transport systems also would fail to convey increased lipid levels beyond that point. WAT possesses sensory innervation exemplified by proven sensory-associated peptides in nerves within the tissue and by viral sensory nerve-specific transneuronal tract tracer, H129 strain of herpes simplex virus 1 labeling of dorsal root ganglia (DRG) pseudounipolar neurons, spinal cord and central sensory circuits. Leptin as a paracrine factor activating WAT sensory innervation could supply the brain with FPS information. Therefore, we tested for and found the presence of the long form of the leptin receptor (Ob-Rb) on DRG pseudounipolar neurons immunohistochemically labeled after injections of Fluorogold, a retrograde tract tracer, into inguinal WAT (IWAT). Intra-IWAT leptin injections (300 ng) significantly elevated IWAT nerve spike rate within 5 min and persisted for at least 30 min. Intra-IWAT leptin injections also induced significant c-Fos immunoreactivity (ir), indicating neural activation across DRG pseudounipolar sensory neurons labeled with Fluorogold IWAT injections. Intraperitoneal leptin injection did not increase c-Fos-ir in DRG or the arcuate nucleus, nor did it increase arcuate signal transducer and activator of transcription 3 phosphorylation-ir. Collectively, these results strongly suggest that endogenous leptin secreted from white adipocytes functions as a paracrine factor to activate spinal sensory nerves innervating the tissue.
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Affiliation(s)
- Keegan T Murphy
- Department of Biology, Obesity Reversal Center, Georgia State University, Atlanta, Georgia; and
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Effects of dietary high fat on prostate intraepithelial neoplasia in TRAMP mice. Lab Anim Res 2013; 29:39-47. [PMID: 23573107 PMCID: PMC3616208 DOI: 10.5625/lar.2013.29.1.39] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/04/2013] [Accepted: 03/05/2013] [Indexed: 12/22/2022] Open
Abstract
Increased fat intake is known to be a major cause of prostate cancer. In this study, we investigated the effect of dietary high fat on prostate intraepithelial neoplasia using transgenic adenocarcinoma mouse prostate (TRAMP) mice. Six-week-old male TRAMP mice were fed AIN93G (control group, 4.0 kcal/kg, n=6) and AIN93G-HFD (experimental group, 4.8 kcal/kg, n=7) for 10 weeks. Prostate histopathology, urogenital tract (UGT) weight, epididymal white adipose tissue weight, argyrophilic nucleolar organizer regions (AgNORs) counts, and serum leptin levels were examined. AIN93G-HFD fed group showed progressed neoplastic lesions in the prostate (P<0.05) compared to AIN93G fed group. AIN93G-HFD intake resulted in a increase in the weight of UGT (P<0.05) and epididymal white adipose tissue. The number of Ag-NOR positive dots significantly increased in each prostate lobe and final serum leptin levels in AIN93G-HFD fed group were about twice those of AIN93G fed group (P<0.05). Dietary high fat was related to the prostate cancer progression in the early stage of TRAMP mice and increased serum leptin levels, suggesting that the regulation of dietary components could delay the progression of prostate cancer.
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Abstract
Leptin therapy in human recombinant form has recently been used in HIV-associated lipodystrophy syndrome on experimental basis in some small short-term clinical trials. It has shown its beneficial effects only in hypoleptinemic HIV-infected patients by causing definite improvement in their insulin sensitivity, glucose tolerance, lipid status, and truncal obesity. Leptin prevents lipotoxicity and activates insulin signaling pathways through several postulated mechanisms. Central leptin insufficiency with peripheral hyperleptinemia has come out to be a significant contributor to the development of obesity and metabolic syndrome. In this article, we will review the basis of leptin therapy in HIV patients, with its promises. However, further larger clinical trials are needed to prove its long-term efficacy in the control of metabolic complications related to HIV therapy.
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Affiliation(s)
- Uma Sinha
- Department of Medicine, Nilratan Sircar Medical College, Kolkata, India
| | - Keshab Sinharay
- Department of Medicine, Nilratan Sircar Medical College, Kolkata, India
| | - Nilanjan Sengupta
- Department of Endocrinology, Nilratan Sircar Medical College, Kolkata, India
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Karvonen-Gutierrez C, Sowers MF, Heeringa S. Sex dimorphism in the association of cardiometabolic characteristics and osteophytes-defined radiographic knee osteoarthritis among obese and non-obese adults: NHANES III. Osteoarthritis Cartilage 2012; 20:614-21. [PMID: 22521953 PMCID: PMC3595163 DOI: 10.1016/j.joca.2012.02.644] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 02/02/2012] [Accepted: 02/27/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To examine the relationship of knee osteoarthritis (OA) with cardiovascular and metabolic risk factors by obesity status and gender. METHODS Data from 1,066 National Health and Nutrition Examination Survey III participants (≥60 years of age) was used to examine relationships of osteophytes-defined radiographic knee OA and cardiovascular and metabolic measures. Analyses were considered among obese [body mass index (BMI)≥30 kg/m(2)] and non-obese (BMI<30 kg/m(2)) men and women. RESULTS The prevalence of osteophytes-defined radiographic knee OA was 34%. Leptin levels and homeostatic model assessment-insulin resistance (HOMA-IR), a proxy measure of insulin resistance, were significantly associated with knee OA; those with knee OA had 35% higher HOMA-IR values and 52% higher leptin levels compared to those without knee OA. The magnitude of the association between HOMA-IR and knee OA was strongest among men, regardless of obesity status; odds ratios (ORs) for HOMA-IR were 34% greater among non-obese men (OR=1.18) vs obese women (OR=0.88). Among obese women, a 5-μg/L higher leptin was associated with nearly 30% higher odds of having knee OA (OR=1.28). Among men, ORs for the association of leptin and knee OA were in the opposite direction. CONCLUSIONS Cardiometabolic dysfunction is related to osteophytes-defined radiographic knee OA prevalence and persists within subgroups defined by obesity status and gender. A sex dimorphism in the direction and magnitude of cardiometabolic risk factors with respect to knee OA was described including HOMA-IR being associated with OA prevalence among men while leptin levels were most important among women.
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Affiliation(s)
- C.A. Karvonen-Gutierrez
- University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor, MI, USA,Address correspondence and reprint requests to: Carrie A. Karvonen-Gutierrez, UM School of Public Health, Department of Epidemiology, 1415 Washington Heights, Room 1858, Ann Arbor, MI 48109, USA. Tel: 734-763-0571; Fax: 734-764-6250. (C.A. Karvonen-Gutierrez)
| | - MF.R. Sowers
- University of Michigan School of Public Health, Department of Epidemiology, Ann Arbor, MI, USA
| | - S.G. Heeringa
- University of Michigan, Institute for Social Research, Ann Arbor, MI, USA
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Ergenoğlu MA, Yeniel AÖ, Akdoğan A, Göker ENT, Tavmergen E. The effects of GnRH analogs on serum and follicular fluid leptin levels and pregnancy outcomes in short protocols of assisted reproductive technology. J Turk Ger Gynecol Assoc 2012; 13:91-7. [PMID: 24592015 DOI: 10.5152/jtgga.2012.10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 01/19/2012] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To determine serum and follicular leptin levels in patients using gonadotropin releasing hormone agonist and antagonist in Assisted Reproductive Technology short protocol cycles and to evaluate pregnancy outcomes. MATERIAL AND METHODS Patients randomly selected to join assisted reproductive technology cycles during February 2004-July 2004 were enrolled in this study. Group 1 consisted of 21 patients receiving r FSH+ GnRH agonists, whereas Group 2 consisted of 34 patients who received r FSH +GnRH antagonists. During the ovulation induction period 5 serum samples were collected (induction day 1, day 3 or antagonist starting day, human chorionic hormone day, oocyte pickup day, and twelfth day of embryo transfer). Follicular fluid samples were collected to be evaluated for leptin, estradiol, prolactin and luteinizing hormone. RESULTS There was no difference in age, basal FSH, basal LH, and basal E2 between groups. Serum leptin levels were similar in both groups. Also, when each group's serum leptin levels were evaluated according to the presence of pregnancy, there was no significant difference in both groups. When follicle leptin levels were evaluated according to the existence of pregnancy, in both groups the follicle leptin levels were lower in pregnant participants but this difference was not statistically significant. When obesity is defined as body mass index over 26.5, there is a correlation between obesity and leptin levels in Group 2. CONCLUSION Our results have shown that both agonists and antagonists have similar efficacy and effect in poor responder women. Leptin levels in either groups, whether pregnant or non-pregnant were not statistically different. This result shows the need for more studies on leptin in infertility.
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Affiliation(s)
- Mete Ahmet Ergenoğlu
- Department of Gynecology and Obstetrics, Faculty of Medicine, Ege University, İzmir, Turkey
| | - Ahmet Özgür Yeniel
- Department of Gynecology and Obstetrics, Faculty of Medicine, Ege University, İzmir, Turkey
| | - Ayşin Akdoğan
- Family Planning and Infertility Research and Treatment Center, Ege University, İzmir, Turkey
| | | | - Erol Tavmergen
- Department of Gynecology and Obstetrics, Faculty of Medicine, Ege University, İzmir, Turkey
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Kim KJ, Kim JY, Park SJ, Yoon H, Yoon CH, Kim WU, Cho CS. Serum leptin levels are associated with the presence of syndesmophytes in male patients with ankylosing spondylitis. Clin Rheumatol 2012; 31:1231-8. [PMID: 22644087 DOI: 10.1007/s10067-012-1999-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/31/2012] [Accepted: 05/08/2012] [Indexed: 10/28/2022]
Abstract
The aim of this study is to clarify the association between serum leptin levels and the presence of syndesmophytes in male patients with ankylosing spondylitis (AS). Seventy-two male patients with AS and 20 age-matched healthy male controls were included. Patients were stratified by the presence of syndesmophytes. Serum leptin levels were measured and adjusted for body mass index (BMI). In addition, bone-specific alkaline phosphatase (BALP), osteocalcin, and telopeptide of type I collagen were determined. Patients with syndesmophytes were associated with older age (p < 0.001), longer disease duration (p = 0.003), and higher BMI (p = 0.038). Serum leptin levels and leptin per BMI (leptin/BMI) ratio were not different between AS patients and healthy controls. However, serum leptin/BMI ratio was significantly higher in patients with syndesmophytes compared to those without (p = 0.010). In multivariate analysis, higher serum leptin/BMI ratio remained significantly associated with the presence of syndesmophytes (p = 0.029). Moreover, serum leptin/BMI ratio was positively correlated with serum BALP (γ = 0.279, p = 0.039). However, there was no significant association between serum leptin/BMI ratio and bone mineral density. Serum leptin levels are elevated in male AS patients with syndesmophytes and were found to be correlated with bone formation marker, suggesting a potential role of leptin in new bone formation in AS.
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Affiliation(s)
- Ki-Jo Kim
- Division of Rheumatology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Riggs PK, Vaida F, Rossi SS, Sorkin LS, Gouaux B, Grant I, Ellis RJ. A pilot study of the effects of cannabis on appetite hormones in HIV-infected adult men. Brain Res 2011; 1431:46-52. [PMID: 22133305 DOI: 10.1016/j.brainres.2011.11.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 10/18/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
Abstract
RATIONALE The endocannabinoid system is under active investigation as a pharmacological target for obesity management due to its role in appetite regulation and metabolism. Exogenous cannabinoids such as tetrahydrocannabinol (THC) stimulate appetite and food intake. However, there are no controlled observations directly linking THC to changes of most of the appetite hormones. OBJECTIVES We took the opportunity afforded by a placebo-controlled trial of smoked medicinal cannabis for HIV-associated neuropathic pain to evaluate the effects of THC on the appetite hormones ghrelin, leptin and PYY, as well as on insulin. METHODS In this double-blind cross-over study, each subject was exposed to both active cannabis (THC) and placebo. RESULTS Compared to placebo, cannabis administration was associated with significant increases in plasma levels of ghrelin and leptin, and decreases in PYY, but did not significantly influence insulin levels. CONCLUSION These findings are consistent with modulation of appetite hormones mediated through endogenous cannabinoid receptors, independent of glucose metabolism.
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Affiliation(s)
- Patricia K Riggs
- Center for Medicinal Cannabis Research (CMCR) and HIV Neurobehavioral Research Center (HNRC), University of California, San Diego, USA.
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65
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Graf C. Preventing and treating obesity in pediatrics through physical activity. EPMA J 2011; 2:261-70. [PMID: 23199161 PMCID: PMC3405396 DOI: 10.1007/s13167-011-0091-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 05/25/2011] [Indexed: 12/14/2022]
Abstract
The prevalence of juvenile obesity is increasing worldwide. Throughout Europe, ca. 20% are affected, in Germany 15%. Many modifiable and nonmodifiable causes have been determined and included, but are not limited to genetic, familiar, and lifestyle factors. In addition, obesity disproportionately affects minority and low socioeconomic status groups. Juvenile obesity increases the risk of having multiple cardiovascular and metabolic diseases, psycho-social problems, and a variety of other co-morbidities. The burden upon the health services cannot yet be estimated. Therefore, there is a need for preventive and therapeutic counter-measures. Until now, most approaches focus on changing the behaviour of individuals in diet and exercise. Based on the existing data researchers agree that programmes should start as early as possible and involve children's environment (family, peers etc.). In conclusion, a positive public health approach including political, environmental, sociocultural, and educational strategies offer the best chance of preventing and reducing juvenile obesity.
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Affiliation(s)
- Christine Graf
- Deutsche Sporthochschule Köln, Institut für Bewegungs- und Neurowissenschaft, Abteilung für Bewegungs- und Gesundheitsförderung, Am Sportpark Müngersdorf 6, 50933 Köln, Germany
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66
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Jahan S, Zinnat R, Hassan Z, Biswas KB, Habib SH. Gender differences in serum leptin concentrations from umbilical cord blood of newborn infants born to nondiabetic, gestational diabetic and type-2 diabetic mothers. Int J Diabetes Dev Ctries 2011; 29:155-8. [PMID: 20336197 PMCID: PMC2839129 DOI: 10.4103/0973-3930.57346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 09/12/2009] [Indexed: 11/04/2022] Open
Abstract
To investigate gender differences, if any, in leptin concentrations from umbilical cord blood of new born infants of mothers with type 2 diabetes mellitus (DM), gestational diabetes mellitus (GDM), and Non diabetic (ND) at delivery. Serum leptin concentrations were measured in 105 newborns (53 males and 52 females in the three groups). Blood was taken from the umbilical cord of the babies at delivery. Maternal anthropometric measurements were recorded within 48 hours after delivery. Pearson correlation coefficient was used to explore the relationship between serum leptin concentrations and anthropometric measures of the fetus and their mother. Both Serum leptin level and serum C-peptide was measured by chemiluminescence based ELISA. The median range of leptin concentration in cord blood was ND group: Male [13.91 (3.22 - 47.63)], Female [16.88 (2 - 43.65)]; GDM group: Male [32 (7 - 76.00)], Female [36.73 (4.80 - 81.20)]; DM group: Male [20.90 (2 -76.00)], Female [32 {2.58 - 80.67)]. Cord serum leptin levels correlated with birth weight(r=0.587, p=0.0001), ponderal index (PI) (r=.319, p=0.024)of the babies and body mass index (BMI) (r=-0.299, p=0.035) of their mothers but did not correlate with gestational age, cord serum C-peptide concentration or placental weight at delivery. Leptin concentrations were higher in the female fetus in comparison to the male fetus. Birth weight of the female fetuses were also higher than that of male fetus. We found that there are very strong associations between cord leptin concentrations at delivery and birth weight, ponderal index of the baby, body mass index of the mothers with Type 2 DM. We also found that high leptin levels could represent an important feedback modulator of substrate supply and subsequently for adipose tissue status during late gestation or adipose tissue is the major determinant of circulating leptin levels.
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Affiliation(s)
- Samsad Jahan
- Department of Gynecology and Obstetrics, Bangladesh Institute of Research and Rehabilitation in Diabetes Endocrine and Metabolic Disorders (BIRDEM), Dhaka, Bangladesh
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67
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Ikeda Y, Nakajima A, Aiba A, Koda M, Okawa A, Takahashi K, Yamazaki M. Association between serum leptin and bone metabolic markers, and the development of heterotopic ossification of the spinal ligament in female patients with ossification of the posterior longitudinal ligament. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2011; 20:1450-8. [PMID: 21258825 DOI: 10.1007/s00586-011-1688-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 12/11/2010] [Accepted: 01/09/2011] [Indexed: 12/12/2022]
Abstract
Obesity is a risk factor for ossification of the posterior longitudinal ligament (OPLL) of the spine, which is characterized by heterotopic bone formation in the posterior longitudinal spinal ligament. Hyperleptinemia is a common feature of obese people and leptin is believed to be an important factor in the pathogenesis of OPLL. However, the association between leptin and bone metabolism and the development of OPLL is not understood fully. The objective of the present study was to determine the association between serum leptin concentration and bone metabolic markers and the extent of heterotopic ossification of the spinal ligament in patients with OPLL. The serum concentrations of leptin, insulin, fructosamine, bone-specific alkaline phosphatase, and carboxyterminal propeptide of type I procollagen, urine deoxypyridinoline levels, and the number of vertebrae with OPLL involvement were measured in 125 (68 males and 57 females) patients with OPLL. The correlation between leptin and these other factors was then examined. Serum leptin and insulin concentrations were increased significantly in OPLL females compared to non-OPLL female controls. In the females with OPLL, serum leptin concentrations corrected for body mass index correlated positively with the number of vertebrae with OPLL involvement. In females, serum leptin levels were significantly higher in patients in whom OPLL extended to the thoracic and/or lumbar spine than in patients in whom OPLL was limited to the cervical spine. Our results suggest that hyperleptinemia, in combination with hyperinsulinemia, may contribute to the development of heterotopic ossification of the spinal ligament in female patients with OPLL.
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Affiliation(s)
- Yoshikazu Ikeda
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan
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68
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Wu X, Patki A, Lara-Castro C, Cui X, Zhang K, Walton RG, Osier MV, Gadbury GL, Allison DB, Martin M, Garvey WT. Genes and biochemical pathways in human skeletal muscle affecting resting energy expenditure and fuel partitioning. J Appl Physiol (1985) 2010; 110:746-55. [PMID: 21109598 DOI: 10.1152/japplphysiol.00293.2010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Genes influencing resting energy expenditure (REE) and respiratory quotient (RQ) represent candidate genes for obesity and the metabolic syndrome because of the involvement of these traits in energy balance and substrate oxidation. We aim to explore the molecular basis for individual variation in REE and fuel partitioning as reflected by RQ. We performed microarray studies in human vastus lateralis muscle biopsies from 40 healthy subjects with measured REE and RQ values. We identified 2,392 and 1,115 genes significantly correlated with REE and RQ, respectively. Genes correlated with REE and RQ encompass a broad array of functions, including carbohydrate and lipid metabolism, gene expression, mitochondrial processes, and membrane transport. Microarray pathway analysis revealed that REE was positively correlated with upregulation of G protein-coupled receptor signaling (meet criteria/total genes: 65 of 283) involved in autonomic nervous system functions, including those receptors mediating adrenergic, dopamine, γ-aminobutyric acid (GABA), neuropeptide Y (NPY), and serotonin action (meet criteria/total genes: 46 of 176). Reduced REE was associated with an increase in genes participating in ubiquitin-proteasome-dependent proteolytic pathways (58 of 232). Serine-type peptidase activity (9 of 76) was positively correlated with RQ, while genes involved in the protein phosphatase type 2A complex (4 of 9), mitochondrial function and cellular respiration (38 of 315), and unfolded protein binding (19 of 97) were associated with reduced RQ values and a preference for lipid fuel metabolism. Individual variations in whole body REE and RQ are regulated by differential expressions of specific genes and pathways intrinsic to skeletal muscle.
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Affiliation(s)
- Xuxia Wu
- Dept. of Nutrition Sciences, The Univ. of Alabama at Birmingham, 1675 University Blvd., Birmingham, AL 35294-3360, USA
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69
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Thompson OM, Beresford SAA, Kirk EA, Bronner MP, Vaughan TL. Serum leptin and adiponectin levels and risk of Barrett's esophagus and intestinal metaplasia of the gastroesophageal junction. Obesity (Silver Spring) 2010; 18:2204-11. [PMID: 20111023 PMCID: PMC3125020 DOI: 10.1038/oby.2009.508] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Persons diagnosed with Barrett's esophagus (BE) are at increased risk of developing esophageal adenocarcinoma (EA). Obesity is a major risk factor for both BE and EA. The primary purposes of this study were to determine whether circulating levels of leptin and adiponectin, both of which are deregulated in obese states, predict risk of specialized intestinal metaplasia (SIM) occurring in the esophagus (BE) and/or gastroesophageal junction, and evaluate the extent to which they mediate the relationship between obesity and these conditions. In this case-control study, 177 persons newly diagnosed with SIM were compared with 173 general population controls using unconditional logistic regression. Females in the highest tertiles of BMI and waist circumference were at the greatest risk (adjusted odds ratio (OR) = 4.6 (95% confidence interval (CI) = 1.9, 11.6), P(trend) = 0.002; OR = 5.1 (95% CI = 2.0, 13.0), P(trend) = 0.002, respectively) compared to females in the lowest tertiles. Adjustment for leptin and adiponectin attenuated these associations by 52 and 42%, respectively. Males in the highest tertile of waist-to-hip ratio were at the greatest risk (adjusted OR = 2.8 (95% CI = 1.3, 5.9), P(trend) = 0.014) compared to males in the lowest tertile. However, adjustment for leptin and adiponectin did not attenuate these associations. Our study results are consistent with the notion that circulating leptin and adiponectin partially mediate the obesity-BE relationship in women. Leptin and adiponectin's role in the progression from normal epithelium to SIM/BE and on to EA should be further elucidated.
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Affiliation(s)
- Olivia M Thompson
- Nutritional Sciences Program, The University of Washington, Seattle, Washington, USA.
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70
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Tolson KP, Gemelli T, Gautron L, Elmquist JK, Zinn AR, Kublaoui BM. Postnatal Sim1 deficiency causes hyperphagic obesity and reduced Mc4r and oxytocin expression. J Neurosci 2010; 30:3803-12. [PMID: 20220015 PMCID: PMC3285557 DOI: 10.1523/jneurosci.5444-09.2010] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/21/2009] [Accepted: 01/29/2010] [Indexed: 12/27/2022] Open
Abstract
Single-minded 1 (SIM1) mutations are one of the few known causes of nonsyndromic monogenic obesity in both humans and mice. Although the role of Sim1 in the formation of the hypothalamus has been described, its postdevelopmental, physiological functions have not been well established. Here we demonstrate that postnatal CNS deficiency of Sim1 is sufficient to cause hyperphagic obesity. We conditionally deleted Sim1 after birth using CaMKII-Cre (alpha-calcium/calmodulin-dependent protein kinase II-Cre) lines to recombine a floxed Sim1 allele. Conditional Sim1 heterozygotes phenocopied germ line Sim1 heterozygotes, displaying hyperphagic obesity and increased length. We also generated viable conditional Sim1 homozygotes, demonstrating that adult Sim1 expression is not essential for mouse or neuron survival and revealing a dosage-dependent effect of Sim1 on obesity. Using stereological cell counting, we showed that the phenotype of both germ line heterozygotes and conditional Sim1 homozygotes was not attributable to global hypocellularity of the paraventricular nucleus (PVN) of the hypothalamus. We also used retrograde tract tracing to demonstrate that the PVN of germ line heterozygous mice projects normally to the dorsal vagal complex and the median eminence. Finally, we showed that conditional Sim1 homozygotes and germ line Sim1 heterozygotes exhibit a remarkable decrease in hypothalamic oxytocin (Oxt) and PVN melanocortin 4 receptor (Mc4r) mRNA. These results demonstrate that the role of Sim1 in feeding regulation is not limited to formation of the PVN or its projections and that the hyperphagic obesity in Sim1-deficient mice may be attributable to changes in the leptin-melanocortin-oxytocin pathway.
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MESH Headings
- Animals
- Animals, Newborn
- Basic Helix-Loop-Helix Transcription Factors/deficiency
- Basic Helix-Loop-Helix Transcription Factors/genetics
- Eating/genetics
- Female
- Gene Expression Regulation, Developmental
- Gene Silencing
- Hyperphagia/genetics
- Hyperphagia/metabolism
- Hyperphagia/pathology
- Hyperphagia/physiopathology
- Hypothalamus/metabolism
- Hypothalamus/pathology
- Hypothalamus/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Obesity/genetics
- Obesity/metabolism
- Obesity/pathology
- Obesity/physiopathology
- Oxytocin/antagonists & inhibitors
- Oxytocin/biosynthesis
- Oxytocin/genetics
- Paraventricular Hypothalamic Nucleus/metabolism
- Paraventricular Hypothalamic Nucleus/pathology
- Paraventricular Hypothalamic Nucleus/physiopathology
- RNA, Messenger/antagonists & inhibitors
- RNA, Messenger/biosynthesis
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/biosynthesis
- Receptor, Melanocortin, Type 4/genetics
- Repressor Proteins/deficiency
- Repressor Proteins/genetics
- Reproducibility of Results
- Signal Transduction/genetics
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Affiliation(s)
| | | | - Laurent Gautron
- Division of Hypothalamic Research
- Departments of Internal Medicine
- Pharmacology, and
- Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Joel K. Elmquist
- Division of Hypothalamic Research
- Departments of Internal Medicine
- Pharmacology, and
- Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, and
| | - Andrew R. Zinn
- McDermott Center for Human Growth and Development
- Departments of Internal Medicine
| | - Bassil M. Kublaoui
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
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71
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Deemer SE, King GA, Dorgo S, Vella CA, Tomaka JW, Thompson DL. Relationship of leptin, resting metabolic rate, and body composition in premenopausal hispanic and non-Hispanic White women. Endocr Res 2010; 35:95-105. [PMID: 20712423 PMCID: PMC4635679 DOI: 10.3109/07435800.2010.496088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The purpose was to evaluate the relationships between fasting serum leptin, resting metabolic rate (RMR), and body composition in premenopausal Hispanic and non-Hispanic White (White) women. METHODS Participants were 67 Hispanic and 43 White women who arrived at the laboratory in a fasted state for measurement of RMR by indirect calorimetry, bone mineral content measured by dual-energy X-ray absorptiometry, and body density measured by hydrodensitometry. Serum leptin levels were determined by EIA. RESULTS Multiple regression analysis revealed that body mass and lean body mass were the best predictors of RMR. Leptin was not a significant predictor of RMR. CONCLUSION Further research needs to be done to examine the role of leptin on metabolism, especially in ethnic groups predisposed to development of obesity and related disorders.
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Affiliation(s)
- Sarah E. Deemer
- Department of Kinesiology, University of Texas at El Paso, El Paso, Texas, USA
| | - George A. King
- Department of Kinesiology, University of Texas at El Paso, El Paso, Texas, USA
| | - Sandor Dorgo
- Department of Kinesiology, University of Texas at El Paso, El Paso, Texas, USA
| | - Chantal A. Vella
- Department of Kinesiology, University of Texas at El Paso, El Paso, Texas, USA
| | - Joe W. Tomaka
- Department of Public Health, University of Texas at El Paso, El Paso, Texas, USA
| | - Dixie L. Thompson
- Department of Exercise, Sport, and Leisure Studies, University of Tennessee, Knoxville, Tennessee, USA
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72
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Shi H, Seeley RJ, Clegg DJ. Sexual differences in the control of energy homeostasis. Front Neuroendocrinol 2009; 30:396-404. [PMID: 19341761 PMCID: PMC4517605 DOI: 10.1016/j.yfrne.2009.03.004] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 03/09/2009] [Accepted: 03/17/2009] [Indexed: 12/20/2022]
Abstract
The prevalence of obesity has reached epidemic proportion with enormous costs in both human lives and healthcare dollars spent. Obesity-related metabolic disorders are much lower in premenopausal women than men; however, there is a dramatic increase following menopause in women. The health risks associated with obesity vary depending on the location of adipose tissue. Adipose tissue distributed in the abdominal visceral carry a much greater risk for metabolic disorders than does adipose tissue distributed subcutaneously. There are distinct sex-dependent differences in the regional fat distribution, women carry more fat subcutaneously whereas men carry more fat viscerally. Males and females differ with respect to their regulation of energy homeostasis. Peripheral adiposity hormones such as leptin and insulin as well as sex hormones directly influence energy balance. Sexual dimorphisms in energy balance, body fat distribution, and the role sex hormones have in mediating these differences are the focus of this review.
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Affiliation(s)
- Haifei Shi
- Obesity Research Center, University of Cincinnati, Cincinnati, OH, USA
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73
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Martin SS, Qasim A, Reilly MP. Leptin resistance: a possible interface of inflammation and metabolism in obesity-related cardiovascular disease. J Am Coll Cardiol 2008; 52:1201-10. [PMID: 18926322 DOI: 10.1016/j.jacc.2008.05.060] [Citation(s) in RCA: 340] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 05/28/2008] [Indexed: 01/19/2023]
Abstract
Leptin is an adipocyte-derived hormone and cytokine that regulates energy balance through a wide range of functions, including several that are important to cardiovascular health. Increased circulating leptin, a marker of leptin resistance, is common in obesity and independently associated with insulin resistance and cardiovascular disease (CVD) in humans. The mechanisms of leptin resistance include genetic mutation, leptin self-regulation, limited tissue access, and cellular or circulating molecular regulation. Evidence suggests that central leptin resistance causes obesity and that obesity-induced leptin resistance injures numerous peripheral tissues, including liver, pancreas, platelets, vasculature, and myocardium. This metabolic- and inflammatory-mediated injury may result from either resistance to leptin's action in selective tissues, or excess leptin action from adiposity-associated hyperleptinemia. In this sense, the term "leptin resistance" encompasses a complex pathophysiological phenomenon. The leptin axis has functional interactions with elements of metabolism, such as insulin, and inflammation, including mediators of innate immunity, such as interleukin-6. Leptin is even purported to physically interact with C-reactive protein, resulting in leptin resistance, which is particularly intriguing, given C-reactive protein's well-studied relationship to cardiovascular disease. Given that plasma levels of leptin and inflammatory markers are correlated and also predict cardiovascular risk, it is conceivable that part of this risk may be mediated through leptin resistance-related insulin resistance, chronic inflammation, type II diabetes, hypertension, atherothrombosis, and myocardial injury. Leptin resistance and its interactions with metabolic and inflammatory factors, therefore, represent potential novel diagnostic and therapeutic targets in obesity-related cardiovascular disease.
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Affiliation(s)
- Seth S Martin
- Department of Medicine, Cardiovascular Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6160, USA
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74
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Al-Shoumer KA, Al-Asousi AA, Doi SA, Vasanthy BA. Serum leptin and its relationship with metabolic variables in Arabs with type 2 diabetes mellitus. Ann Saudi Med 2008; 28:367-70. [PMID: 18779635 PMCID: PMC6074485 DOI: 10.5144/0256-4947.2008.367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Most studies on serum leptin in type 2 diabetes mellitus have focused on white populations. We studied serum leptin concentrations and parameters related to glycemic control and the association between leptin levels and anthropometric and metabolic factors in Arab patients with type 2 diabetes and in Arab control subjects. SUBJECTS AND METHODS Ninety-two patients (65 females and 27 males) with type 2 diabetes and 69 matched normal control subjects (48 females and 21 males) were included. Anthropometric measures (including body mass index [BMI] and waist:hip ratio) were assessed in all subjects. After an overnight fast, blood was collected for serum leptin assay. Other metabolic parameters including glucose, insulin, C-peptide, intact proinsulin, insulin resistance index (HOMA-IR), insulin-like growth factor 1 (IGF-1), lipids and hemoglobin A1c (HbA1c) were determined. RESULTS Fasting serum leptin levels, IGF-1 and high-density lipoprotein (HDL) cholesterol were similar in patients with type 2 diabetes and control subjects. When obese subjects (BMI > or =30 kg/m2) were analyzed separately, serum levels of leptin were significantly lower in patients compared to controls. In contrast, patients had higher fasting glucose, insulin, C-peptide, intact proinsulin, insulin resistance, total cholesterol, triglycerides, HbA1c, and a larger waist circumference and waist-to-hip ratio than controls. Serum leptin correlated positively with BMI, negatively with waist-to-hip ratio, and demonstrated no relationship to other parameters. CONCLUSION Patients with type 2 diabetes in an Arab ethnic population showed evidence of an unfavorable metabolic profile despite having leptin levels similar to controls. Obesity influences serum leptin levels more significantly in type 2 diabetes, in which leptin levels tends to be low.
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Affiliation(s)
- Kamal A Al-Shoumer
- Division of Endocrinology and Metabolic Medicine, Mubarak Al-Kabeer Hospital, Kuwait University, Jabriya, Kuwait.
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75
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Castaneda-Sceppa C, Sarnak MJ, Wang X, Greene T, Madero M, Kusek JW, Beck G, Kopple JD, Levey AS, Menon V. Role of adipose tissue in determining muscle mass in patients with chronic kidney disease. J Ren Nutr 2007; 17:314-22. [PMID: 17720100 PMCID: PMC2699417 DOI: 10.1053/j.jrn.2007.05.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE Malnutrition is a powerful predictor of mortality in chronic kidney disease (CKD). However, its etiology is unclear. We hypothesized that the adipocyte-derived proteins leptin and adiponectin, inflammation (as measured by C-reactive protein, CRP), and insulin resistance (as measured by homeostasis model assessment, HOMA), implicated in the malnutrition-inflammation complex syndrome commonly seen in maintenance dialysis patients, would be associated with the loss of muscle mass in earlier stages of CKD. Arm muscle area was used as an indicator of muscle mass. PATIENTS AND SETTING The Modification of Diet in Renal Disease Study cohort of people with CKD stages 3 and 4 was used for analysis (N = 780). MAIN OUTCOME MEASURES Regression models were carried out to examine the relationships of leptin, adiponectin, CRP, and HOMA with arm muscle area (the main study outcome). RESULTS Arm muscle area was 39 +/- 15 cm(2) (mean +/- SD), and adiponectin levels were 13 +/- 7 microg/mL. Median and interquartile range (IQR) concentrations were: 9.0 (13.6) ng/mL for leptin, 2.3 (4.9) mg/L for CRP, and 2.4 (2.0) for HOMA. Higher leptin (beta coefficient and 95% confidence interval, -6.9 [-8.7 to -5.1], P < .001) and higher CRP (beta coefficient and 95% confidence interval, -2.7 [-3.9 to -1.4], P < .001) were associated with lower arm muscle area. There was a trend toward lower arm muscle area with higher adiponectin (P = .07), but no association with HOMA (P = .80). CONCLUSION Leptin and CRP were associated with lower muscle mass in subjects with CKD at stages 3 and 4. Further studies are needed to understand the mechanisms underlying these associations, and to develop targeted interventions for this patient population.
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Affiliation(s)
- Carmen Castaneda-Sceppa
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts 02111, USA.
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76
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Ataseven H, Bahcecioglu IH, Kuzu N, Yalniz M, Celebi S, Erensoy A, Ustundag B. The levels of ghrelin, leptin, TNF-alpha, and IL-6 in liver cirrhosis and hepatocellular carcinoma due to HBV and HDV infection. Mediators Inflamm 2007; 2006:78380. [PMID: 17047295 PMCID: PMC1618941 DOI: 10.1155/mi/2006/78380] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Background/Aim. Malnutrition, a common
problem in liver cirrhosis and HCC, may readily deteriorate the
clinical functions with resultant poor prognosis. Beside the hyper
catabolic state frequently encountered in chronic liver disease
and HCC, anorexia and reduced food intake also worsen the
malnutrition. The recently discovered peptide hormone ghrelin acts
as a counterpart of leptin in regulation of food intake and fat
utilization. The aim of the present study was to investigate the
ghrelin and leptin levels in cirrhosis and HCC due to hepatitis B
and D viruses, and the association of ghrelin and leptin with
TNF-α, IL-6 and the severity of the disease.
Materials and methods. We measured serum ghrelin, leptin,
TNF-α, and IL-6 levels using specific immunoassay in 45
patients (23 cirrhosis, 22 HCC) with HBV and/or HDV and in 25
control subjects. Results. In comparison to controls,
serum ghrelin, TNF-α, and IL-6 levels were significantly
higher in cirrhosis and HCC (P < .05), whereas serum leptin levels
were found decreased (P < .05). There was a positive correlation
between ghrelin and TNF-α, and a negative correlation
between leptin and TNF-α (P < .05). Conclusion.
In cirrhosis and HCC due to HBV or HDV, serum ghrelin levels were
increased with a corresponding decrease in serum leptin
concentrations, acting as a physiological counterpart of ghrelin.
The increasing of ghrelin is more prominent in Child C cirrhosis
and the level was correlated with TNF-α. The presence of
nutritional and metabolic abnormalities, including malnutrition,
in cirrhosis and HCC may, at least partly, elucidate high ghrelin
and low leptin levels.
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Affiliation(s)
- Huseyin Ataseven
- Department of Gastroenterology, School of Medicine, Firat University,
23200 Elazığ, Turkey
- *Huseyin Ataseven:
| | | | - Nalan Kuzu
- Department of Internal Medicine, School of Medicine, Firat University, 23200 Elazığ, Turkey
| | - Mehmet Yalniz
- Department of Gastroenterology, School of Medicine, Firat University,
23200 Elazığ, Turkey
| | - Selman Celebi
- Department of Gastroenterology, School of Medicine, Firat University,
23200 Elazığ, Turkey
| | - Ahmet Erensoy
- Department of Microbiology, School of Medicine, Firat University, 23200 Elazığ, Turkey
| | - Bilal Ustundag
- Department of Biochemistry, School of Medicine, Firat University, 23200 Elazığ, Turkey
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77
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Buyukberber M, Koruk M, Savas MC, Gulsen MT, Pehlivan Y, Deveci R, Sevinc A, Gergerlioglu S. Leptin levels in the differential diagnosis between benign and malignant ascites. World J Gastroenterol 2007; 13:398-402. [PMID: 17230608 PMCID: PMC4065894 DOI: 10.3748/wjg.v13.i3.398] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the role of leptin levels in the differential diagnosis of ascites.
METHODS: Ascitic leptin, TNFα and serum leptin levels were measured in 77 patients with ascites (35 with malignancies, 30 cirrhosis and 12 tuberculosis). Control serum samples were obtained from 20 healthy subjects. Leptin and TNFα levels were measured by ELISA. Body mass index (BMI) and percentage of body fat (BFM) by skin fold measurement were calculated for all patients and control groups. Peritoneal biopsy, ascites cytology and cultures or biochemical values were used for the diagnosis of patients.
RESULTS: In patients with malignancies, the mean serum and ascites leptin levels and their ratios were significantly decreased compared to the other patient groups and controls. In tuberculosis peritonitis, ascitic fluid TNFα levels were significantly higher than malignant ascites and cirrhotic sterile ascites. BMI and BFM values did not distinguish between patients and controls.
CONCLUSION: In patients with malignant ascites, levels of leptin and TNFα were significantly lower than in patients with tuberculous ascites.
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Affiliation(s)
- Mehmet Buyukberber
- Department of Gastroenterology, Gaziantep University, School of Medicine, 27310 Gaziantep, Turkey
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78
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Mahabir S, Baer D, Johnson LL, Roth M, Campbell W, Clevidence B, Taylor PR. Body Mass Index, percent body fat, and regional body fat distribution in relation to leptin concentrations in healthy, non-smoking postmenopausal women in a feeding study. Nutr J 2007; 6:3. [PMID: 17229323 PMCID: PMC1781463 DOI: 10.1186/1475-2891-6-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2006] [Accepted: 01/17/2007] [Indexed: 11/24/2022] Open
Abstract
Background The relationship between BMI and leptin has been studied extensively in the past, but previous reports in postmenopausal women have not been conducted under carefully controlled dietary conditions of weight maintenance using precise measures of body fat distribution. The aim of the present study was to examine the association between serum leptin concentration and adiposity as estimated by BMI and dual energy x-ray absorptiometry (DEXA) measures (percent body fat, central and peripheral fat, and lean mass) in postmenopausal women. Methods This study was conducted as a cross-sectional analysis within the control segment of a randomized, crossover trial in which postmenopausal women (n = 51) consumed 0 (control), 15 (one drink), and 30 (two drinks) g alcohol (ethanol)/d for 8 weeks as part of a controlled diet. BMIs were determined and DEXA scans were administered to the women during the 0 g alcohol treatment, and a blood sample was collected at baseline and week 8 of each study period for leptin analysis. Results and discussion In multivariate analysis, women who were overweight (BMI > 25 to ≤ 30 kg/m2) had a 2-fold increase, and obese women (BMI > 30 kg/m2) had more than a 3-fold increase in serum leptin concentrations compared to normal weight (BMI ≤25 kg/m2) women. When the models for the different measures of adiposity were assessed by multiple R2, models which included percent body fat explained the highest proportion (approximately 80%) of the serum leptin variance. Conclusion Under carefully controlled dietary conditions, we confirm that higher levels of adiposity were associated with higher concentrations of serum leptin. It appears that percent body fat in postmenopausal women may be the best adiposity-related predictor of serum leptin.
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Affiliation(s)
- Somdat Mahabir
- Department of Epidemiology, Division of Cancer Prevention and Population Sciences, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - David Baer
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Laura L Johnson
- National Center for Complementary and Alternative Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Mark Roth
- Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Institutes of Health, Bethesda, MD, USA
| | - William Campbell
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Beverly Clevidence
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Philip R Taylor
- Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Institutes of Health, Bethesda, MD, USA
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79
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Abstract
Adiponectin circulates in human plasma mainly as a 180-kDa low molecular weight (LMW) hexamer and a high molecular weight (HMW) multimer of approximately 360 kDa. We comprehensively examined the relationships between circulating levels of total adiponectin, adiponectin multimers, and the relative distribution (i.e., ratio) of multimeric forms with key features of the metabolic syndrome. Total adiponectin (r = 0.45), HMW (r = 0.47), LMW (r = 0.31), and HMW-to-total adiponectin ratio (r = 0.29) were significantly correlated with insulin-stimulated glucose disposal rate. Similarly, total (r = -0.30), HMW (r = -0.38), and HMW-to-total adiponectin ratio (r = -0.34) were correlated with central fat distribution but not with total fat mass or BMI. Regarding energy metabolism, although there were no effects on resting metabolic rate, total (r = 0.41) and HMW (r = 0.44) were associated with increasing rates of fat oxidation. HMW-to-total adiponectin ratio increased as a function of total adiponectin, and it was HMW quantity (not total or HMW-to-total adiponectin ratio or LMW) that was primarily responsible for all of these relationships. Impact on nuclear magnetic resonance lipoprotein subclasses was assessed. HMW and total adiponectin were correlated with decreases in large VLDL (r = -0.44 and -0.41); decreases in small LDL (r = -0.41 and -0.36) and increases in large LDL (r = 0.36 and 0.30) particle concentrations accompanied by increased LDL particle size (r = 0.47 and 0.39); and increases in large HDL (r = 0.45 and 0.37) and HDL particle size (r = 0.53 and 0.47). Most of these correlations persisted after adjustment for metabolic covariables. In conclusion, first, serum adiponectin is associated with increased insulin sensitivity, reduced abdominal fat, and high basal lipid oxidation; however, it is HMW quantity, not total or HMW-to-total adiponectin ratio, that is primarily responsible for these relationships. Second, reduced quantities of HMW independently recapitulate the lipoprotein subclass profile associated with insulin resistance after correcting for glucose disposal rate and BMI. Finally, HMW adiponectin is an important factor in explaining the metabolic syndrome.
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Affiliation(s)
- Cristina Lara-Castro
- Department of Nutrition Sciences, 1675 Webb Nutrition Sciences Bldg., Room 244, University of Alabama, Birmingham, AL 35294, USA.
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80
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Bolukbas FF, Bolukbas C, Horoz M, Gumus M, Erdogan M, Zeyrek F, Yayla A, Ovunc O. Child-Pugh classification dependent alterations in serum leptin levels among cirrhotic patients: a case controlled study. BMC Gastroenterol 2004; 4:23. [PMID: 15387890 PMCID: PMC522814 DOI: 10.1186/1471-230x-4-23] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Accepted: 09/23/2004] [Indexed: 01/12/2023] Open
Abstract
Background As anorexia and hypermetabolism are common in cirrhosis, leptin levels may be increased in this disease. In this study, we investigated the relation between the severity of disease and serum leptin levels in post-hepatitis cirrhosis and the role of body composition, gender and viral aetiology of cirrhosis in this association. Methods Thirty-five cases with post-hepatitis cirrhosis and 15 healthy controls were enrolled in this study. Body composition including body mass index, body fat percentage and body fat mass were determined. Serum leptin levels were assayed. Results Leptin levels were significantly higher among cirrhotic patients independent of sex compared to controls (p = 0.001). Female patients in both groups have had higher leptin levels than males (in cirrhotics p = 0.029, in controls p = 0.02). Cirrhotic patients in each of A, B and C subgroups according to the Child- Pugh classification revealed significantly different levels compared to controls (p = 0.046, p = 0.004, p = 0.0001, respectively). Male cirrhotics in Child-Pugh Class B and C subgroups had significantly higher leptin levels compared to male controls (p = 0.006, p = 0.008). On the other hand, female patients only in Child Pugh class C subgroup have had higher levels of serum leptin compared to controls (p = 0.022). Child-Pugh classification has been found to be the sole discriminator in determination of leptin levels in cirrhotics by linear regression (beta: 0.435 p = 0.015). Conclusion Serum leptin levels increase in advanced liver disease independently of gender, body composition in posthepatitic cirrhosis. The increase is more abundant among patients that belong to C subgroup according to the Child- Pugh classification.
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Affiliation(s)
- Fusun F Bolukbas
- Department of Internal Medicine, Gastroenterology Division, Harran University, Medical Faculty, Sanliurfa, Turkey
| | - Cengiz Bolukbas
- Department of Internal Medicine, Gastroenterology Division, Harran University, Medical Faculty, Sanliurfa, Turkey
| | - Mehmet Horoz
- Department of Internal Medicine, Harran University, Medical Faculty, Sanliurfa, Turkey
| | - Mahmut Gumus
- Internal Medicine Clinic, Dr.Lutfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey
| | - Mehmet Erdogan
- Internal Medicine Clinic, Dr.Lutfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey
| | - Fadile Zeyrek
- Department of Microbiology, Harran University, Medical Faculty, Sanliurfa, Turkey
| | - Ali Yayla
- Internal Medicine Clinic, Dr.Lutfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey
| | - Oya Ovunc
- Gastroenterology Clinic, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey
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81
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Martin K, Wallace P, Rust PF, Garvey WT. Estimation of resting energy expenditure considering effects of race and diabetes status. Diabetes Care 2004; 27:1405-11. [PMID: 15161796 DOI: 10.2337/diacare.27.6.1405] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate the impact of diabetes status and race, in addition to other covariables, on the estimation of resting energy expenditure (REE). RESEARCH DESIGN AND METHODS Demographic, anthropometric, and clinical parameters were assessed in 166 adults of varying weights. Subjects were categorized by race (white versus black) and into three subgroups based on glucose tolerance (normoglycemia, impaired glucose tolerance, and type 2 diabetes), termed the diabetes status index (DSI). REE was measured by indirect calorimetry. A multiple regression model was established for optimal prediction of REE based on covariables. RESULTS An average decrease in REE of 135 kcal/day independent of all other variables was observed in blacks (P < 0.001). DSI was found to be a significant covariable (P = 0.002) in predicting REE, which was observed to be higher in diabetic women. Therefore, race and DSI entered the multiple regression equation to predict REE as significant independent variables, together with lean body mass (LBM) and age x BMI interaction (P < 0.001). Overall, REE prediction resulted in an R(2) of 0.79 and a root mean square error of 136 kcal/day. These values indicate that the resultant equations could offer advantages over other key published prediction equations. The equations are: 1) REE(female) = 803.8 + 0.3505 x age x (BMI - 34.524) - 135.0 x race + 15.866 x LBM + 50.90 x DSI; and 2) REE(male) = 909.4 + 0.3505 x age x (BMI -34.524) -135.0 x race + 15.866 x LBM -9.10 x DSI. The predictive value of the equations did not diminish substantially when fat-free mass estimated by skinfold calipers was substituted for dual-energy X-ray absorptiometry scan measurements of LBM. CONCLUSIONS Race and diabetes status are important when predicting REE, coupled with LBM, age, BMI, and sex. Race and DSI have not been considered in equations commonly used to predict REE. Their inclusion could improve individualization of dietary prescriptions for type 2 diabetic subjects and heterogeneous populations.
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Affiliation(s)
- Kelley Martin
- General Clinical Research Center, Medical University of South Carolina, Charleston, SC, USA
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82
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Anderwald C, Brabant G, Bernroider E, Horn R, Brehm A, Waldhäusl W, Roden M. Insulin-dependent modulation of plasma ghrelin and leptin concentrations is less pronounced in type 2 diabetic patients. Diabetes 2003; 52:1792-8. [PMID: 12829648 DOI: 10.2337/diabetes.52.7.1792] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The gastric peptide ghrelin augments and the adipocyte-derived hormone leptin reduces appetite and food intake. In the central nervous system, insulin directly decreases hunger sensation but could also act indirectly by modulating ghrelin and leptin secretion. This study examines dose-dependent effects of insulin on plasma ghrelin and leptin concentrations during hyperinsulinemic (1, 2, and 4 mU x kg(-1) x min(-1))-euglycemic clamp tests in six nondiabetic (control subjects) and six type 2 diabetic patients. Type 2 diabetic patients were studied before and after prolonged (12-h and 67-h) variable intravenous insulin treatment aiming at near-normoglycemia (115 +/- 4 mg/dl). Nondiabetic subjects were also studied during saline infusion, which did not affect ghrelin but decreased leptin by 19 +/- 6% (P < 0.03). In control subjects, plasma ghrelin decreased at all clamp steps (-17 +/- 1, -27 +/- 6, and -33 +/- 4%, respectively; P < 0.006 vs. baseline), whereas leptin increased by 35 +/- 11% (P < 0.05). In type 2 diabetic patients without insulin treatment, ghrelin decreased by 18 +/- 7% (P < 0.05) only after 4 mU x kg(-1) x min(-1) insulin infusion and leptin increased by 19 +/- 6% (P < 0.05). After prolonged insulin treatment and near-normoglycemia, ghrelin and leptin remained unchanged in type 2 diabetic patients during the clamps. In conclusion, insulin reduces plasma ghrelin in nondiabetic patients and, to a lesser extent, in type 2 diabetic patients before insulin therapy. These findings indicate an indirect effect of insulin via ghrelin on the suppression of hunger sensation and appetite.
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Affiliation(s)
- Christian Anderwald
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, University of Vienna Medical School, Vienna, Austria
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83
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Garvey WT, Kwon S, Zheng D, Shaughnessy S, Wallace P, Hutto A, Pugh K, Jenkins AJ, Klein RL, Liao Y. Effects of insulin resistance and type 2 diabetes on lipoprotein subclass particle size and concentration determined by nuclear magnetic resonance. Diabetes 2003; 52:453-62. [PMID: 12540621 DOI: 10.2337/diabetes.52.2.453] [Citation(s) in RCA: 447] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The insulin resistance syndrome (IRS) is associated with dyslipidemia and increased cardiovascular disease risk. A novel method for detailed analyses of lipoprotein subclass sizes and particle concentrations that uses nuclear magnetic resonance (NMR) of whole sera has become available. To define the effects of insulin resistance, we measured dyslipidemia using both NMR lipoprotein subclass analysis and conventional lipid panel, and insulin sensitivity as the maximal glucose disposal rate (GDR) during hyperinsulinemic clamps in 56 insulin sensitive (IS; mean +/- SD: GDR 15.8 +/- 2.0 mg. kg(-1). min(-1), fasting blood glucose [FBG] 4.7 +/- 0.3 mmol/l, BMI 26 +/- 5), 46 insulin resistant (IR; GDR 10.2 +/- 1.9, FBG 4.9 +/- 0.5, BMI 29 +/- 5), and 46 untreated subjects with type 2 diabetes (GDR 7.4 +/- 2.8, FBG 10.8 +/- 3.7, BMI 30 +/- 5). In the group as a whole, regression analyses with GDR showed that progressive insulin resistance was associated with an increase in VLDL size (r = -0.40) and an increase in large VLDL particle concentrations (r = -0.42), a decrease in LDL size (r = 0.42) as a result of a marked increase in small LDL particles (r = -0.34) and reduced large LDL (r = 0.34), an overall increase in the number of LDL particles (r = -0.44), and a decrease in HDL size (r = 0.41) as a result of depletion of large HDL particles (r = 0.38) and a modest increase in small HDL (r = -0.21; all P < 0.01). These correlations were also evident when only normoglycemic individuals were included in the analyses (i.e., IS + IR but no diabetes), and persisted in multiple regression analyses adjusting for age, BMI, sex, and race. Discontinuous analyses were also performed. When compared with IS, the IR and diabetes subgroups exhibited a two- to threefold increase in large VLDL particle concentrations (no change in medium or small VLDL), which produced an increase in serum triglycerides; a decrease in LDL size as a result of an increase in small and a reduction in large LDL subclasses, plus an increase in overall LDL particle concentration, which together led to no difference (IS versus IR) or a minimal difference (IS versus diabetes) in LDL cholesterol; and a decrease in large cardioprotective HDL combined with an increase in the small HDL subclass such that there was no net significant difference in HDL cholesterol. We conclude that 1) insulin resistance had profound effects on lipoprotein size and subclass particle concentrations for VLDL, LDL, and HDL when measured by NMR; 2) in type 2 diabetes, the lipoprotein subclass alterations are moderately exacerbated but can be attributed primarily to the underlying insulin resistance; and 3) these insulin resistance-induced changes in the NMR lipoprotein subclass profile predictably increase risk of cardiovascular disease but were not fully apparent in the conventional lipid panel. It will be important to study whether NMR lipoprotein subclass parameters can be used to manage risk more effectively and prevent cardiovascular disease in patients with the IRS.
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Affiliation(s)
- W Timothy Garvey
- Division of Endocrinology and Department of Medicine, Medical University of South Carolina, Charleston 29425, USA.
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84
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Affiliation(s)
- W Timothy Garvey
- Division of Endocrinology, Diabetes, and Medical Genetics and Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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85
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Brown JL, Spicer MT, Spicer LJ. Effect of high-fat diet on body composition and hormone responses to glucose tolerance tests. Endocrine 2002; 19:327-32. [PMID: 12624434 DOI: 10.1385/endo:19:3:327] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2002] [Revised: 11/13/2002] [Accepted: 11/13/2002] [Indexed: 11/11/2022]
Abstract
To determine potential hormonal mediators of the effect of high-fat diets on the development of insulin resistance, blood leptin, growth hormone (GH), glucose, and insulin responses to a 2 g/kg BW oral glucose challenge were evaluated in weanling female Sprague Dawley rats that were randomly assigned to a high-fat (HF, 39% of calories, 20% fat by weight; n = 10) and moderate-fat (MF, 22% of calories, 10% fat by weight; n = 10) diets. Oral glucose challenges were administered following 5, 7, and 9 wk on the feeding trial. Animals were provided diet in excess of their requirements for growth. Body mass analysis was conducted by dual X-ray absorptiometry (DXA) on the 6th, 8th, and 10th weeks of the trial. HF animals gained more weight after 7 wk, had greater body fat than the MF animals, and similar glucose responses to the oral glucose challenges. HF rats secreted more insulin and leptin compared to MF animals. Lean body mass and serum GH and IGF-I concentrations were not different between the groups. Results of this study demonstrate that leptin but not GH or IGF-I is involved in the development of insulin resistance in growing rats as a result of excess energy intake in the form of dietary fat.
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Affiliation(s)
- J L Brown
- Department of Nutritional Sciences, Oklahoma State University, Stillwater 74078, USA
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86
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Lichnovská R, Gwozdziewiczová S, Hrebícek J. Gender differences in factors influencing insulin resistance in elderly hyperlipemic non-diabetic subjects. Cardiovasc Diabetol 2002; 1:4. [PMID: 12423554 PMCID: PMC140144 DOI: 10.1186/1475-2840-1-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2002] [Accepted: 10/14/2002] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The increase in the prevalence of insulin resistance-related metabolic syndrome, a disorder that greatly increases the risk of diabetes, heart attack and stroke, is alarming. One of the most frequent and early symptoms of metabolic syndrome is hypertriglyceridemia. We examined the gender differences between various metabolic factors related to insulin resistance in elderly non-diabetic men and postmenopausal women of comparable age suffering from hypertriglyceridemia, and compared them with healthy subjects of equal age. RESULTS The indexes of insulin resistance HOMA IR and QUICKI were significantly higher in both hyperlipemic men and women than in controls; 95% confidence limits of hyperlipemic subjects did not overlap with controls. In both normolipemic and hyperlipemic men and women serum leptin correlated significantly with insulin resistance, while HDL-cholesterol correlated inversely with HOMA-IR only in women (both normo- and hyperlipemic), and serum tumor necrosis factor alpha (TNFalpha) only in hyperlipemic women. According to results of multiple regression analysis with HOMA-IR as a dependent variable, leptin played a significant role in determining insulin resistance in both genders, but--aside from leptin--triglycerides, TNFalpha and decreased HDL-cholesterol were significant determinants in women, while body mass index and decreased HDL-cholesterol were significant determinants in men. The coefficient of determination (R2) of HOMA IR by above mentioned metabolic variables was in women above 60%, in men only about 40%. CONCLUSION The significant role of serum leptin in determination of insulin resistance in both elderly men and postmenopausal women of equal age was confirmed. However, the study also revealed significant gender differences : in women a strong influence of triglycerides, TNFalpha and decreased HDL-cholesterol, in men only a mild role of BMI and decreased HDL-cholesterol.
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Affiliation(s)
- Radka Lichnovská
- Institute of Physiology, Faculty of Medicine, Palacký University, Olomouc, Czech Republic
| | - Simona Gwozdziewiczová
- Institute of Physiology, Faculty of Medicine, Palacký University, Olomouc, Czech Republic
| | - Jirí Hrebícek
- Institute of Physiology, Faculty of Medicine, Palacký University, Olomouc, Czech Republic
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87
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Willi SM, Kennedy A, Wallace P, Ganaway E, Rogers NL, Garvey WT. Troglitazone antagonizes metabolic effects of glucocorticoids in humans: effects on glucose tolerance, insulin sensitivity, suppression of free fatty acids, and leptin. Diabetes 2002; 51:2895-902. [PMID: 12351424 DOI: 10.2337/diabetes.51.10.2895] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glucocorticoids induce insulin resistance in humans, whereas thiazolidinediones enhance insulin sensitivity. Although the effects of glucocorticoids and thiazolidinediones have been assessed in isolation, interaction between these drugs, which both act as ligands for nuclear receptors, has been less well studied. Therefore, we examined the metabolic effects of dexamethasone and troglitazone, alone and in combination, for the first time in humans. A total of 10 healthy individuals with normal glucose tolerance (age 40 +/- 11 years, BMI 31 +/- 6.1 kg/m(2)) were sequentially studied at baseline, after 4 days of dexamethasone (4 mg/day), after 4-6 weeks on troglitazone alone (400 mg/day), and again after 4 days of dexamethasone added to troglitazone. Key metabolic variables included glucose tolerance assessed by blood glucose and insulin responses to an oral glucose tolerance test (OGTT), insulin sensitivity evaluated via hyperinsulinemic-euglycemic clamp, free fatty acids (FFAs) and FFA suppressibility by insulin during the clamp study, and fasting serum leptin. Dexamethasone drastically impaired glucose tolerance, with fasting and 2-h OGTT insulin values increasing by 2.3-fold (P < 0.001) and 4.4-fold (P < 0.001) over baseline values, respectively. The glucocorticoid also induced a profound state of insulin resistance, with a 34% reduction in maximal glucose disposal rates (GDRs; P < 0.001). Troglitazone alone increased GDRs by 20% over baseline (P = 0.007) and completely prevented the deleterious effects of dexamethasone on glucose tolerance and insulin sensitivity, as illustrated by a return of OGTT glucose and insulin values and maximal GDR to near-baseline levels. Insulin-mediated FFA suppressibility (FFA decline at 30 min during clamp/FFA at time 0) was also markedly reduced by dexamethasone (P = 0.002). Troglitazone had no effect per se, but it was able to normalize FFA suppressibility in subjects coadministered dexamethasone. Futhermore, the magnitudes of response of FFA suppressibility and GDR to dexamethasone were proportionate. The same was true for the reversal of dexamethasone-induced insulin resistance by troglitazone, but not in response to troglitazone alone. Leptin levels were increased 2.2-fold above baseline by dexamethasone. Again, troglitazone had no effect per se but blocked the dexamethasone-induced increase in leptin. Subjects experienced a 1.7-kg weight gain while taking troglitazone but no other untoward effects. We conclude that in healthy humans, thiazolidinediones antagonize the action of dexamethasone with respect to multiple metabolic effects. Specifically, troglitazone reverses both glucocorticoid-induced insulin resistance and impairment of glucose tolerance, prevents dexamethasone from impairing the antilipolytic action of insulin, and blocks the increase in leptin levels induced by dexamethasone. Even though changes in FFA suppressibility were correlated with dexamethasone-induced insulin resistance and its reversal by troglitazone, a cause-and-effect relationship cannot be established. However, the data suggest that glucocorticoids and thiazolidinediones exert fundamentally antagonistic effects on human metabolism in both adipose and muscle tissues. By preventing or reversing insulin resistance, troglitazone may prove to be a valuable therapeutic agent in the difficult clinical task of controlling diabetes in patients receiving glucocorticoids.
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Affiliation(s)
- Steven M Willi
- Department of Pediatrics, Medical University of South Carolina, Charleston 29425, USA.
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88
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Corominola H, Conner LJ, Beavers LS, Gadski RA, Johnson D, Caro JF, Rafaeloff-Phail R. Identification of novel genes differentially expressed in omental fat of obese subjects and obese type 2 diabetic patients. Diabetes 2001; 50:2822-30. [PMID: 11723066 DOI: 10.2337/diabetes.50.12.2822] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Obesity is associated with an increased risk for developing type 2 diabetes, insulin resistance, hypertension, dyslipidemia, cardiovascular disease, respiratory dysfunction, and certain forms of cancer. Insulin resistance in many type 2 diabetic patients is the result of increased visceral adiposity. To identify novel genes implicated in type 2 diabetes and/or obesity and to elucidate the molecular mechanisms underlying both diseases, we analyzed gene expression in omental fat from lean and obese nondiabetic subjects and obese type 2 diabetic patients using mRNA differential display and subtracted library techniques. After screening over 13,800 subtracted cDNA clones and 6,912 cDNA amplification products, we identified 2,078 cDNAs that showed potential differential expression in the omental fat of lean versus obese nondiabetic subjects versus obese type 2 diabetic patients. Data analysis showed that 70.7% of these clones corresponded to unknown genes (26.7% matched express sequence tags [ESTs]) and 29.3% corresponded to known genes. Reverse Northern and classic Northern analyses further confirmed that the expression of five of these cDNA clones was elevated in obese nondiabetic subjects and obese type 2 diabetic patients. Four candidate genes were further evaluated for tissue distribution, which showed expression primarily in adipose and skeletal muscle tissue, and chromosomal localization. We concluded that both mRNA differential display and subtracted cDNA libraries are powerful tools for identifying novel genes implicated in the pathogenesis of obesity and type 2 diabetes.
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Affiliation(s)
- H Corominola
- Servei d'Endocrinologia, IDIBAPS-Institut d'Investigacions, Biomèdiques, August Pi i Sunyer Hospital Clinic, Barcelona, Spain
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89
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Lloyd RV, Jin L, Tsumanuma I, Vidal S, Kovacs K, Horvath E, Scheithauer BW, Couce ME, Burguera B. Leptin and leptin receptor in anterior pituitary function. Pituitary 2001; 4:33-47. [PMID: 11824506 DOI: 10.1023/a:1012982626401] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Leptin is a 16 kDa protein that exerts important effects on the regulation of food intake and energy expenditure by interacting with the leptin receptor in the brain and in many other tissues. Although leptin is produced mainly by white adipose tissue, several laboratories have shown low levels of leptin production by a growing number of tissues including the anterior pituitary gland. Many studies have implicated leptin in anterior pituitary function including the observation that homozygous mutations of the leptin receptor gene led to morbid obesity, lack of pubertal development and decreased GH and TSH secretion. In addition, leptin functions as a neuroendocrine hormone and regulates many metabolic activities. Leptin also interacts with and regulates the hypothalamic-pituitary-adrenal, the hypothalamic-pituitary-thyroid and the hypothalamic-pituitary-gonadal axes. All of the anterior pituitary cell types express the leptin receptor. However, leptin has been localized in specific subtypes of anterior pituitary cells indicating cell type-specific production of leptin in the anterior pituitary. Subcellular localization of leptin indicates co-storage with secretory granules and implicates hypothalamic releasing hormones in leptin secretion from anterior pituitary hormone cells. Leptin signal transduction in the anterior pituitary has been shown to involve the janus protein-tyrosine kinase (JAK)/signal transducer and activation of transcription (STAT) as well as suppressor of cytokine signalling (SOCS). These proteins are activated by tyrosine-phosphorylation in anterior pituitary cells. The various steps in pituitary leptin signal transduction remain to be elucidated.
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Affiliation(s)
- R V Lloyd
- Department of Laboratory Medicine and Pathology, Mayo Foundation, Rochester, MN 55905, USA
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90
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Argyropoulos G, Brown AM, Willi SM, Zhu J, He Y, Reitman M, Gevao SM, Spruill I, Garvey WT. Effects of mutations in the human uncoupling protein 3 gene on the respiratory quotient and fat oxidation in severe obesity and type 2 diabetes. J Clin Invest 1998; 102:1345-51. [PMID: 9769326 PMCID: PMC508981 DOI: 10.1172/jci4115] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Human uncoupling protein 3 (UCP3) is a mitochondrial transmembrane carrier that uncouples oxidative ATP phosphorylation. With the capacity to participate in thermogenesis and energy balance, UCP3 is an important obesity candidate gene. A missense polymorphism in exon 3 (V102I) was identified in an obese and diabetic proband. A mutation introducing a stop codon in exon 4 (R143X) and a terminal polymorphism in the splice donor junction of exon 6 were also identified in a compound heterozygote that was morbidly obese and diabetic. Allele frequencies of the exon 3 and exon 6 splice junction polymorphisms were determined and found to be similar in Gullah-speaking African Americans and the Mende tribe of Sierra Leone, but absent in Caucasians. Moreover, in exon 6-splice donor heterozygotes, basal fat oxidation rates were reduced by 50%, and the respiratory quotient was markedly increased compared with wild-type individuals, implicating a role for UCP3 in metabolic fuel partitioning.
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Affiliation(s)
- G Argyropoulos
- Department of Medicine, Division of Endocrinology, Medical University of South Carolina, 29425, USA.
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91
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Kirchgessner TG, Uysal KT, Wiesbrock SM, Marino MW, Hotamisligil GS. Tumor necrosis factor-alpha contributes to obesity-related hyperleptinemia by regulating leptin release from adipocytes. J Clin Invest 1997; 100:2777-82. [PMID: 9389742 PMCID: PMC508482 DOI: 10.1172/jci119824] [Citation(s) in RCA: 297] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cytokines, in particular tumor necrosis factor-alpha (TNF-alpha), have significant effects on energy metabolism and appetite although their mechanisms of action are largely unknown. Here, we examined whether TNF-alpha modulates the production of leptin, the recently identified fat-specific energy balance hormone, in cultured adipocytes and in mice. TNF-alpha treatment of 3T3-L1 adipocytes resulted in rapid stimulation of leptin accumulation in the media, with a maximum effect at 6 h. This stimulation was insensitive to cycloheximide, a protein synthesis inhibitor, but was completely inhibited by the secretion inhibitor brefeldin A, indicating a posttranslational effect. Treatment of mice with TNF-alpha also caused a similar increase in plasma leptin levels. Finally, in obese TNF-alpha-deficient mice, circulating leptin levels were significantly lower, whereas adipose tissue leptin was higher compared with obese wild-type animals. These data provide evidence that TNF-alpha can act directly on adipocytes to regulate the release of a preformed pool of leptin. Furthermore, they suggest that the elevated adipose tissue expression of TNF-alpha that occurs in obesity may contribute to obesity-related hyperleptinemia.
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Affiliation(s)
- T G Kirchgessner
- Bristol-Myers Squibb Co., Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA
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