1
|
Chen YQ, Pottanat TG, Siegel RW, Ehsani M, Qian YW, Zhen EY, Regmi A, Roell WC, Guo H, Luo MJ, Gimeno RE, Van't Hooft F, Konrad RJ. Angiopoietin-like protein 8 differentially regulates ANGPTL3 and ANGPTL4 during postprandial partitioning of fatty acids. J Lipid Res 2020; 61:1203-1220. [PMID: 32487544 PMCID: PMC7397750 DOI: 10.1194/jlr.ra120000781] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/09/2020] [Indexed: 12/11/2022] Open
Abstract
Angiopoietin-like protein (ANGPTL)8 has been implicated in metabolic syndrome and reported to regulate adipose FA uptake through unknown mechanisms. Here, we studied how complex formation of ANGPTL8 with ANGPTL3 or ANGPTL4 varies with feeding to regulate LPL. In human serum, ANGPTL3/8 and ANGPTL4/8 complexes both increased postprandially, correlated negatively with HDL, and correlated positively with all other metabolic syndrome markers. ANGPTL3/8 also correlated positively with LDL-C and blocked LPL-facilitated hepatocyte VLDL-C uptake. LPL-inhibitory activity of ANGPTL3/8 was >100-fold more potent than that of ANGPTL3, and LPL-inhibitory activity of ANGPTL4/8 was >100-fold less potent than that of ANGPTL4. Quantitative analyses of inhibitory activities and competition experiments among the complexes suggested a model in which localized ANGPTL4/8 blocks the LPL-inhibitory activity of both circulating ANGPTL3/8 and localized ANGPTL4, allowing lipid sequestration into fat rather than muscle during the fed state. Supporting this model, insulin increased ANGPTL3/8 secretion from hepatocytes and ANGPTL4/8 secretion from adipocytes. These results suggest that low ANGPTL8 levels during fasting enable ANGPTL4-mediated LPL inhibition in fat tissue to minimize adipose FA uptake. During feeding, increased ANGPTL8 increases ANGPTL3 inhibition of LPL in muscle via circulating ANGPTL3/8, while decreasing ANGPTL4 inhibition of LPL in adipose tissue through localized ANGPTL4/8, thereby increasing FA uptake into adipose tissue. Excessive caloric intake may shift this system toward the latter conditions, possibly predisposing to metabolic syndrome.
Collapse
Affiliation(s)
- Yan Q Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Thomas G Pottanat
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Robert W Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Yue-Wei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Eugene Y Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ajit Regmi
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - William C Roell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Haihong Guo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - M Jane Luo
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ruth E Gimeno
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| | - Ferdinand Van't Hooft
- Division of Cardiovascular Medicine, Department of Medicine Solna, Karolinska Institutet Karolinska University Hospital Solna, Stockholm, Sweden
| | - Robert J Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN
| |
Collapse
|
2
|
Sigit FS, Tahapary DL, Trompet S, Sartono E, Willems van Dijk K, Rosendaal FR, de Mutsert R. The prevalence of metabolic syndrome and its association with body fat distribution in middle-aged individuals from Indonesia and the Netherlands: a cross-sectional analysis of two population-based studies. Diabetol Metab Syndr 2020; 12:2. [PMID: 31921359 PMCID: PMC6947940 DOI: 10.1186/s13098-019-0503-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/09/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The prevalence of metabolic syndrome varies among populations with different ethnicities. Asian populations develop metabolic complications at lower amounts of adiposity than western populations. The role of abdominal obesity in the metabolic differences between the two populations is poorly understood. OBJECTIVES Our objectives were to estimate the prevalence of metabolic syndrome and the relative contribution of its components in the Indonesian and the Dutch population, as well as to examine the associations of overall and abdominal obesity with metabolic syndrome. METHODS In this cross-sectional study of middle-aged adults in the Netherlands Epidemiology of Obesity Study (n = 6602) and the Indonesian National Health Surveillance (n = 10,575), metabolic syndrome was defined by the unified IDF and AHA/NHLBI criteria. We performed logistic and linear regressions to examine associations of BMI and waist circumference with the metabolic syndrome, mutually adjusted for waist circumference and BMI. RESULTS The prevalence of metabolic syndrome was 28% and 46% in Indonesian men and women, and 36% and 24% in Dutch men and women. The most prominent components were hypertension (61%) and hyperglycemia (51%) in the Indonesian, and hypertension (62%) and abdominal obesity (40%) in the Dutch population. Per SD in BMI and waist circumference, odds ratios (ORs, 95% CI) of metabolic syndrome were 1.5 (1.3-1.8) and 2.3 (1.9-2.7) in Indonesian men and 1.7 (1.2-2.5) and 2.9 (2.1-4.1) in Dutch men. The ORs of metabolic syndrome were 1.4 (1.2-1.6) and 2.3 (2.0-2.7) in Indonesian women and 1.0 (0.8-1.3) and 4.2 (3.2-5.4) in Dutch women. CONCLUSION More Indonesian women than men have metabolic syndrome, whereas the opposite is true for the Dutch population. In both the Indonesian and the Dutch populations, hypertension is the primary contributor to the prevalence of metabolic syndrome. In both populations, abdominal adiposity was more strongly associated with metabolic syndrome than overall adiposity.
Collapse
Affiliation(s)
- Fathimah S. Sigit
- Department of Clinical Epidemiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Metabolic, Cardiovascular, and Aging Cluster, The Indonesian Medical Education and Research Institute, Faculty of Medicine-Universitas Indonesia, Jalan Salemba Raya No 6, Jakarta, 10430 Indonesia
| | - Dicky L. Tahapary
- Metabolic, Cardiovascular, and Aging Cluster, The Indonesian Medical Education and Research Institute, Faculty of Medicine-Universitas Indonesia, Jalan Salemba Raya No 6, Jakarta, 10430 Indonesia
- Department of Internal Medicine, Dr. Cipto Mangunkusumo National Referral Hospital, Faculty of Medicine-Universitas Indonesia, Jalan Salemba Raya No 6, Jakarta, 10430 Indonesia
| | - Stella Trompet
- Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Erliyani Sartono
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Ko Willems van Dijk
- Department of Internal Medicine, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Department of Human Genetics, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Frits R. Rosendaal
- Department of Clinical Epidemiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Renée de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| |
Collapse
|
3
|
Sharma AM, Engeli S. The renin-angiotensin system in obesity hypertension. J Renin Angiotensin Aldosterone Syst 2017; 2:S114-S119. [PMID: 28095231 DOI: 10.1177/14703203010020012001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Arya M Sharma
- Franz-Volhard-Klinik at the Max-Delbrück-Center for Molecular Medicine, Universitätsklinikum Charité, Humboldt Universität zu Berlin, Germany,
| | - Stefan Engeli
- Franz-Volhard-Klinik at the Max-Delbrück-Center for Molecular Medicine, Universitätsklinikum Charité, Humboldt Universität zu Berlin, Germany
| |
Collapse
|
4
|
Echavarría-Pinto M, Gonzalo N, Ibañez B, Petraco R, Jimenez-Quevedo P, Sen S, Nijjer S, Tarkin J, Alfonso F, Núñez-Gil IJ, Bañuelos C, Quirós A, Fernández-Ortiz A, Macaya C, Koo BK, Davies J, Escaned J. Low Coronary Microcirculatory Resistance Associated With Profound Hypotension During Intravenous Adenosine Infusion. Circ Cardiovasc Interv 2014; 7:35-42. [DOI: 10.1161/circinterventions.113.000659] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Mauro Echavarría-Pinto
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Nieves Gonzalo
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Borja Ibañez
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Ricardo Petraco
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Pilar Jimenez-Quevedo
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Sayan Sen
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Sukkinder Nijjer
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Jason Tarkin
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Fernando Alfonso
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Ivan J. Núñez-Gil
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Camino Bañuelos
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Alicia Quirós
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Antonio Fernández-Ortiz
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Carlos Macaya
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Bon-Kwon Koo
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Justin Davies
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| | - Javier Escaned
- From the Cardiovascular Institute, Hospital Clínico San Carlos and Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain (M.E.-P., B.I., A.Q., A.F.-O., J.E.); Cardiovascular Institute, Hospital Clínico San Carlos, Madrid, Spain (N.G., P.J.-Q., F.A., I.J.N.-G., C.B., C.M.); International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London and Imperial College Healthcare NHS Trust, London, United Kingdom (R.P., S.S., S.N., J.T., J.D.); and
| |
Collapse
|
5
|
Abstract
High blood pressure is reported in over two-thirds of patients with type 2 diabetes, and its development coincides with the development of hyperglycaemia. Many pathophysiological mechanisms underlie this association. Of these mechanisms, insulin resistance in the nitric-oxide pathway; the stimulatory effect of hyperinsulinaemia on sympathetic drive, smooth muscle growth, and sodium-fluid retention; and the excitatory effect of hyperglycaemia on the renin-angiotensin-aldosterone system seem to be plausible. In patients with diabetes, hypertension confers an enhanced risk of cardiovascular disease. A blood pressure of lower than 140/85 mm Hg is a reasonable therapeutic goal in patients with type 2 diabetes according to clinical trial evidence. People with controlled diabetes have a similar cardiovascular risk to patients without diabetes but with hypertension. A renin-angiotensin system blocker combined with a thiazide-type diuretic might be the best initial antihypertensive regimen for most people with diabetes. In general, the positive effects of antihypertensive drugs on cardiovascular outcomes outweigh the negative effects of antihypertensive drugs on glucose metabolism.
Collapse
Affiliation(s)
- Ele Ferrannini
- Department of Internal Medicine, University of Pisa, Pisa, Italy.
| | | |
Collapse
|
6
|
Bagi Z, Feher A, Cassuto J. Microvascular responsiveness in obesity: implications for therapeutic intervention. Br J Pharmacol 2012; 165:544-60. [PMID: 21797844 DOI: 10.1111/j.1476-5381.2011.01606.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Obesity has detrimental effects on the microcirculation. Functional changes in microvascular responsiveness may increase the risk of developing cardiovascular complications in obese patients. Emerging evidence indicates that selective therapeutic targeting of the microvessels may prevent life-threatening obesity-related vascular complications, such as ischaemic heart disease, heart failure and hypertension. It is also plausible that alterations in adipose tissue microcirculation contribute to the development of obesity. Therefore, targeting adipose tissue arterioles could represent a novel approach to reducing obesity. This review aims to examine recent studies that have been focused on vasomotor dysfunction of resistance arteries in obese humans and animal models of obesity. Particularly, findings in coronary resistance arteries are contrasted to those obtained in other vascular beds. We provide examples of therapeutic attempts, such as use of statins, ACE inhibitors and insulin sensitizers to prevent obesity-related microvascular complications. We further identify some of the important challenges and opportunities going forward. LINKED ARTICLES This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-3.
Collapse
Affiliation(s)
- Zsolt Bagi
- Department of Pharmacology, University of Oxford, UK Department of Physiology, New York Medical College, Valhalla, New York, USA.
| | | | | |
Collapse
|
7
|
Comprehensive MRI analysis of early cardiac and vascular remodeling in middle-aged patients with abdominal obesity. J Hypertens 2012; 30:567-73. [DOI: 10.1097/hjh.0b013e32834f6f3f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
8
|
Bagi Z. Mechanisms of coronary microvascular adaptation to obesity. Am J Physiol Regul Integr Comp Physiol 2009; 297:R556-67. [DOI: 10.1152/ajpregu.90817.2008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The metabolic syndrome (MetS) is associated with clustering of cardiovascular risk factors in individuals that may greatly increase their risk of developing coronary artery disease. Obesity and related metabolic dysfunction are the driving forces in the prevalence of MetS. It is believed that obesity has detrimental effects on cardiovascular function, but its overall impact on the vasomotor regulation of small coronary arteries is still debated. Emerging evidence indicates that in obesity coronary arteries adapt to hemodynamic changes via maintaining and/or upregulating cellular mechanism(s) intrinsic to the vascular wall. Among other factors, endothelial production of cyclooxygenase-2-derived prostacyclin and reactive oxygen species, as well as increased nitric oxide sensitivity and potassium channel activation in smooth muscle cells, have been implicated in maintaining coronary vasodilator function. This review aims to examine studies that have been primarily focused on alterations in coronary vasodilator function in obesity. A better understanding of cellular mechanisms that may contribute to coronary microvascular adaptation may provide insight into the sequence of pathological events in obesity and may allow the harnessing of these effects for therapeutic purposes.
Collapse
|
9
|
Hankinson AL. Epidemiologic and pathophysiologic links between obesity and hypertension. CURRENT CARDIOVASCULAR RISK REPORTS 2009. [DOI: 10.1007/s12170-009-0041-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
10
|
Ferrannini E, Sironi AM, Iozzo P, Gastaldelli A. Intra-abdominal adiposity, abdominal obesity, and cardiometabolic risk. Eur Heart J Suppl 2008. [DOI: 10.1093/eurheartj/sum042] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
11
|
[The effects of three-week fasting diet on blood pressure, lipid profile and glucoregulation in extremely obese patients]. SRP ARK CELOK LEK 2007; 135:440-6. [PMID: 17929537 DOI: 10.2298/sarh0708440b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
INTRODUCTION Obesity is often accompanied by a number of complications including diabetes mellitus and cardiovascular diseases. Elevated blood pressure and lipids, as well as deterioration of glucoregulation are attributed, as the most significant factors, to development of diabetes mellitus and cardiovascular complications in obese patients. OBJECTIVE The aim of our study was to evaluate the effects of a fasting diet on blood pressure, lipid profile and glucoregulatory parameters. METHOD We included 110 patients (33 male and 77 female; mean age 35 +/- 1 years, body weight 131.7 +/- 2.6 kg, body mass index 45.4 +/- 0.8 kg/m2) who were hospitalized for three weeks for the treatment of extreme obesity with the fasting diet. At the beginning, during, and at the end of this period, we evaluated changes in blood pressure, lipid profile, as well as parameters of glucoregulation including glycaemia, insulinaemia, and insulin sensitivity by HOMA. Oral glucose tolerance test (OGTT) was performed in all patients at the beginning and at the end of the fasting diet. RESULTS During the fasting diet, the body weight decreased from 131.7 +/- 2.6 kg to 117.7 +/- 2.4 kg (p < 0.001), the body mass index decreased from 45.4 +/- 0.8 kg/m2 to 40.8 +/- 0.8 kg/m2 (p < 0.001), and both systolic and diastolic blood pressure significantly declined (143 +/- 2 vs. 132 +/- 2 mm Hg, p < 0.001; 92 +/- 2 vs. 85 +/- 2 mm Hg, p < 0.001). In addition, the fasting diet produced a significant decrease in total cholesterol, LDL cholesterol, triglycerides, as well as basal glycaemia and insulinaemia (p < 0.001) Before the fasting diet, OGTT was normal in 76% of patients, whereas 21% of patients showed glucose intolerance, and 4% of patients diabetes mellitus. After the fasting diet, OGTT was normal in 88% of patients, whereas 12% of patients still had signs of glucose intolerance (p < 0.05). In addition, insulin resistance significantly (p < 0.05) increased from 54 +/- 6% to 89 +/- 13% after the fasting diet. CONCLUSION The three-week fasting diet in extremely obese patients produced a significant decrease and normalization of blood pressure, decrease in lipids, and improvement in glucoregulation including the increase in insulin sensitivity.
Collapse
|
12
|
Poirier P, Eckel RH. Cardiovascular Complications of Obesity and the Metabolic Syndrome. CARDIOVASCULAR MEDICINE 2007. [DOI: 10.1007/978-1-84628-715-2_132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
13
|
Foucan L, Deloumeaux J, Donnet JP, Bangou J, Larifla L, Messerchmitt C, Salmi LR, Kangambega P. Metabolic syndrome components in Indian migrants with type 2 diabetes. A matched comparative study. DIABETES & METABOLISM 2006; 32:337-42. [PMID: 16977261 DOI: 10.1016/s1262-3636(07)70288-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To study the metabolic syndrome (MS) in Indian subjects with type 2 diabetes (T2D) in comparing them with controls from the Indian community and from the general population. METHOD An adapted definition of MS by the Third report of the National Cholesterol Education Program's Adult Treatment Panel III was used. We defined three groups matched for sex and age (+/-5 years). Non parametric tests for comparison of matched samples and conditional logistic regression were used. RESULTS We selected 71 Indians with T2D (group 1) and two control groups with fasting blood glucose<6.1 mmol/L: 71 Indians (group 2) and 213 subjects from the general population (group 3). Patients were 24 to 76 years-old and each group contained 56% men. Globally, MS was identified in 77% of the group 1 when diabetes was taken into account. When diabetes was excluded there were 47% of MS in group 1, 18% in group 2 and 16% in group 3. The clusters of four factors (hypertension, large waist circumference, hypertriglyceridemia and Low HDL-C) were more common in Indians. The most frequent factors were hypertriglyceridemia and large waist circumference in Indians. Indians with T2D had a 5-fold higher risk of MS than the general population group, OR (95% CI): 4.93 (2.71 - 8.97); P<0.001. CONCLUSION The high frequency of MS and of hypertriglyceridemia in Indians with T2D highlights the need for screening and management of MS in this population facing a high cardiovascular risk.
Collapse
Affiliation(s)
- L Foucan
- Unit of Clinical Epidemiology and Medicine, University of Antilles, Guyane.
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Leichman JG, Aguilar D, King TM, Vlada A, Reyes M, Taegtmeyer H. Association of plasma free fatty acids and left ventricular diastolic function in patients with clinically severe obesity. Am J Clin Nutr 2006. [DOI: 10.1093/ajcn/84.2.336] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Joshua G Leichman
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| | - David Aguilar
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| | - Terri M King
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| | - Adrian Vlada
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| | - Manuel Reyes
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| | - Heinrich Taegtmeyer
- From the Divisions of Cardiology (JGL, DA, AV, MR, and TH) and Medical Genetics (TMK), University of Texas, Houston Medical School, Houston, TX
| |
Collapse
|
15
|
Pierce CH, Dills RL, Lewandowski TA, Morgan MS, Wessels MA, Shen DD, Kalman DA. Estimation of Background Exposure to Toluene Using a Physiologically‐Based Kinetic Model. J Occup Health 2006. [DOI: 10.1539/joh.39.130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
16
|
Poirier P, Giles TD, Bray GA, Hong Y, Stern JS, Pi-Sunyer FX, Eckel RH. Obesity and cardiovascular disease: pathophysiology, evaluation, and effect of weight loss: an update of the 1997 American Heart Association Scientific Statement on Obesity and Heart Disease from the Obesity Committee of the Council on Nutrition, Physical Activity, and Metabolism. Circulation 2005; 113:898-918. [PMID: 16380542 DOI: 10.1161/circulationaha.106.171016] [Citation(s) in RCA: 1909] [Impact Index Per Article: 100.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Obesity is becoming a global epidemic in both children and adults. It is associated with numerous comorbidities such as cardiovascular diseases (CVD), type 2 diabetes, hypertension, certain cancers, and sleep apnea/sleep-disordered breathing. In fact, obesity is an independent risk factor for CVD, and CVD risks have also been documented in obese children. Obesity is associated with an increased risk of morbidity and mortality as well as reduced life expectancy. Health service use and medical costs associated with obesity and related diseases have risen dramatically and are expected to continue to rise. Besides an altered metabolic profile, a variety of adaptations/alterations in cardiac structure and function occur in the individual as adipose tissue accumulates in excess amounts, even in the absence of comorbidities. Hence, obesity may affect the heart through its influence on known risk factors such as dyslipidemia, hypertension, glucose intolerance, inflammatory markers, obstructive sleep apnea/hypoventilation, and the prothrombotic state, in addition to as-yet-unrecognized mechanisms. On the whole, overweight and obesity predispose to or are associated with numerous cardiac complications such as coronary heart disease, heart failure, and sudden death because of their impact on the cardiovascular system. The pathophysiology of these entities that are linked to obesity will be discussed. However, the cardiovascular clinical evaluation of obese patients may be limited because of the morphology of the individual. In this statement, we review the available evidence of the impact of obesity on CVD with emphasis on the evaluation of cardiac structure and function in obese patients and the effect of weight loss on the cardiovascular system.
Collapse
|
17
|
Randall OS, Kwagyan J, Huang Z, Xu S, Ketete M, Maqbool AR. Effect of diet and exercise on pulse pressure and cardiac function in morbid obesity: analysis of 24-hour ambulatory blood pressure. J Clin Hypertens (Greenwich) 2005; 7:455-63. [PMID: 16103756 PMCID: PMC8109575 DOI: 10.1111/j.1524-6175.2005.04491.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Blood pressure is a major risk factor for cardiovascular events, although the role of pulse pressure, an independent predictor of arterial stiffness, has recently been emphasized. This study examines the baseline relationship between body mass index (BMI) and blood pressure indexes in 215 obese African Americans enrolled in a diet-exercise program. The subject population was 77% female, with a mean +/- SD age of 46.7+/-10.7 years and a mean BMI of 42.5+/-7.5 kg/m2. In addition, the authors prospectively examined the effect of weight loss on cardiovascular parameters in a subset of 25 participants. The results show a closer significant correlation between pulse pressure and BMI (b=1.97 kgm-1; p=0.001) than between systolic blood pressure and BMI (b=1.58 kgm-1; p=0.020). After 3 months of diet and exercise, average reductions were as follows: BMI, 4.2 kg/m2 (p<0.01); systolic blood pressure, 7.2 mm Hg (p<0.01); pulse pressure, 4.8 mm Hg (p<0.01); and cardiac output, 975 mL/min (p<0.01). Compliance index increased by 0.1 mL/mm Hg/m2 (p=0.03). The results highlight the potential value to cardiovascular health of a modest reduction in body weight in obese individuals.
Collapse
Affiliation(s)
- Otelio S Randall
- General Clinical Research Center, Howard University College of Medicine, Washington, DC 20060, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Aoi N, Soma M, Nakayama T, Rahmutula D, Kosuge K, Izumi Y, Matsumoto K. Variable number of tandem repeat of the 5'-flanking region of type-C human natriuretic peptide receptor gene influences blood pressure levels in obesity-associated hypertension. Hypertens Res 2005; 27:711-6. [PMID: 15785005 DOI: 10.1291/hypres.27.711] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The gene for natriuretic peptides receptor C (NPRC), which is a candidate susceptibility gene for essential hypertension (EH) or obese hypertension, plays a key role in the regulation of plasma levels and biological effects of natriuretic peptides. The aims of the present study were to find new genetic markers in the 5'-flanking region of the NPRC gene and to assess relationships between variants and phenotypes of EH, including EH in obese patients. Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis, we discovered a novel six-nucleotide repeat polymorphism located 4 base pairs (bp) upstream of the major transcriptional initiation site. We performed association analysis of this variable number of tandem repeat (VNTR) in 242 EH patients and 212 normotensive controls (NT). Although no significant difference in overall frequency of VNTR was found between NT and EH groups, the blood pressure level of EH patients with the 5/6 genotype was significantly higher in obese subjects. This suggests that the VNTR of the 5'-flanking region of the NPRC gene influences blood pressure levels in obesity-associated hypertension.
Collapse
Affiliation(s)
- Noriko Aoi
- Division of Kidney and Endocrinology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
19
|
Kwagyan J, Tabe CE, Xu S, Maqbool AR, Gordeuk VR, Randall OS. The impact of body mass index on pulse pressure in obesity. J Hypertens 2005; 23:619-24. [PMID: 15716705 DOI: 10.1097/01.hjh.0000160220.71350.5f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Pulse pressure, a marker of arterial vascular properties, has been linked to cardiovascular diseases and complications. This study examined the impact of excess body mass and cardiovascular disease risk factors on pulse pressure (PP). DESIGN Cross-sectional and prospective study. METHODS Baseline data consist of 219 obese African Americans, with mean +/- SD age of 46.8 +/- 10.9 years enrolled in a diet and exercise program of weight reduction. A non-invasive monitoring device was used to acquire 24 hourly ambulatory blood pressures. Pulse pressure was calculated as the difference between the average 24-h systolic and diastolic blood pressure and studied as a continuous variable and according to quartiles. The cross-sectional association of pulse pressure with body mass index (BMI) was examined using multivariate linear regression and proportional odds models that controlled for cardiovascular disease risk factors. In addition, we examined prospectively, in 36 participants, the effect of weight loss on pulse pressure, using the Wilcoxon signed ranked test. RESULTS At baseline, a 5 kg/m2 increase in BMI was independently associated with a 35% risk [relative risk (RR) = 1.35, confidence interval (CI) = 1.10-1.65, P < 0.01] in the general study population and 19% (RR = 1.19, CI = 1.07-1.56, P = 0.04) in obese normotensives for increasing PP by one quartile after adjustment for other significant variables. After 3 months of diet and exercise intervention, BMI decreased by an average of 10.6% (P < 0.01) and resulted in an 8.8% (P < 0.01) reduction in PP. CONCLUSIONS In the context of obesity, increasing BMI is independently associated with decreasing arterial compliance, as reflected in PP. This association highlights the potential value to cardiovascular health of any reduction in body weight in obese individuals.
Collapse
Affiliation(s)
- John Kwagyan
- General Clinical Research Center, Howard University College of Medicine, NW, Washington, DC 20060, USA
| | | | | | | | | | | |
Collapse
|
20
|
Natali A, Ferrannini E. Hypertension, insulin resistance, and the metabolic syndrome. Endocrinol Metab Clin North Am 2004; 33:417-29. [PMID: 15158527 DOI: 10.1016/j.ecl.2004.03.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Impaired glucose homeostasis, hypertriglyceridemia, low high-density lipoprotein cholesterol, high blood pressure, and central obesity tend to cluster in patients to generate a syndrome, the metabolic syndrome. In the adult population, the metabolic syndrome prevalence ranges between 15% and 25%. Poor fibrinolysis and low-grade inflammation also are associated with the metabolic syndrome,and they contribute to make it a condition that predisposes to cardiovascular disease. Insulin resistance and attendant hyperinsulinemia are the characteristic features of the metabolic syndrome and probably are responsible for impairment in glucose homeostasis,dyslipidemia, and higher blood pressure through cause-and-effect relationships. While awaiting the results of clinical trials with cardiovascular endpoints, we should treat the metabolic syndrome with aggressive lifestyle intervention and consider drugs that improve the whole cardiovascular risk profile.
Collapse
Affiliation(s)
- Andrea Natali
- Department of Internal Medicine and CNRS Institute of Clinical Physiology, Univeristy of Pisa School of Medicine, Italy
| | | |
Collapse
|
21
|
Foucan L, Bangou-Brédent J, Ekouévi DK, Deloumeaux J, Roset JE, Kangambega P. Hypertension and combinations of cardiovascular risk factors. An epidemiologic case-control study in an adult population in Guadeloupe (FWI). Eur J Epidemiol 2003; 17:1089-95. [PMID: 12530767 DOI: 10.1023/a:1021213729434] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Our aim was to quantify the association between hypertension and four well-known cardiovascular risk factors (obesity, dyslipidemia, high blood glucose, smoking) and to determine the extent of their combinations in hypertensive subjects in an adult population in Guadeloupe (FWI). A case-control study was conducted in 1999. Odds ratios (ORs) and 95% confidence interval (95% CI) of hypertension according to cardiovascular risk factors were calculated by a logistic regression model. In all, 4210 subjects were included in the study: 2105 hypertensives and 2105 age and sex matched non-hypertensive controls. In the hypertensives, obesity (30%) was the most frequent risk factor followed by dyslipidemia (23.2%), current smoking (11.5%) and high blood glucose (8.2%). But, prevalence of current smokers was higher in normotensives (13.9 vs. 11.5%, p < 0.01). Among cases, 44.5% had no risk factor other than hypertension. The proportion of subjects with multiple risks factors (< or = 2) was higher in hypertensives than in controls (55.5 vs. 6.5%,p < 0.001) and higher in women than in men in cases (58.1 vs. 51.8%, p = 0.005). The adjusted ORs (95% CI) of hypertension were 2.41 (2.02-2.88) for obesity, 1.39 (1.16-1.66) for dyslipidemia and 1.67 (1.20-2.32) for high blood glucose. Our study documents the high prevalence of combinations of cardiovascular risk factors in hypertensive subjects in Guadeloupe and confirms the need of a global risk approach in prevention and treatment of hypertension.
Collapse
Affiliation(s)
- L Foucan
- Département d'Information Médicale et de Santé Publique, CHU de Pointe-à-Pitre, Guadeloupe.
| | | | | | | | | | | |
Collapse
|
22
|
Emdin M, Gastaldelli A, Muscelli E, Macerata A, Natali A, Camastra S, Ferrannini E. Hyperinsulinemia and autonomic nervous system dysfunction in obesity: effects of weight loss. Circulation 2001; 103:513-9. [PMID: 11157715 DOI: 10.1161/01.cir.103.4.513] [Citation(s) in RCA: 157] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Because hyperinsulinemia acutely stimulates adrenergic activity, it has been postulated that chronic hyperinsulinemia may lead to enhanced sympathetic tone and cardiovascular risk. METHODS AND RESULTS In 21 obese (body mass index, 35+/-1 kg/m(2)) and 17 lean subjects, we measured resting cardiac output (by 2-dimensional echocardiography), plasma concentrations and timed (diurnal versus nocturnal) urinary excretion of catecholamines, and 24-hour heart rate variability (by spectral analysis of ECG). In the obese versus lean subjects, cardiac output was increased by 22% (P:<0.03), and the nocturnal drop in urinary norepinephrine output was blunted (P:=0.01). Spectral power in the low-frequency range was depressed throughout 24 hours (P:<0.04). During the afternoon and early night, ie, the postprandial phase, high-frequency power was lower, heart rate was higher; and the ratio of low to high frequency, an index of sympathovagal balance, was increased in direct proportion to the degree of hyperinsulinemia independent of body mass index (partial r=0.43, P:=0.01). In 9 obese subjects who lost 10% to 18% of their body weight, cardiac output decreased and low-frequency power returned toward normal (P:<0.05). CONCLUSIONS In free-living subjects with uncomplicated obesity, chronic hyperinsulinemia is associated with a high-output, low-resistance hemodynamic state, persistent baroreflex downregulation, and episodic (postprandial) sympathetic dominance. Reversal of these changes by weight loss suggests a causal role for insulin.
Collapse
Affiliation(s)
- M Emdin
- Metabolism Unit and Coronary Division, CNR Institute of Clinical Physiology, and Department of Internal Medicine, University of Pisa, Pisa, Italy
| | | | | | | | | | | | | |
Collapse
|
23
|
Pierce CH, Lewandowski TA, Dills RL, Morgan MS, Wessels MA, Shen DD, Kalman DA. A comparison of 1H8- and 2H8-toluene toxicokinetics in men. Xenobiotica 1999; 29:93-108. [PMID: 10078842 DOI: 10.1080/004982599238830] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
1. To examine the bioequivalence of an isotope-labelled tracer to study toxicant disposition, we conducted 33 controlled human exposures to a mixture of 50 ppm 1H8-toluene and 50 ppm 2H8-toluene for 2 h, and measured concentrations in blood and breath, and metabolite levels in urine for 100 h post-exposure. 2. A physiologically based kinetic (PBK) model found that compared with 1H8-toluene, 2H8-toluene had a 6.4+/-13% (mean+/-SD) lower AUC, a 6.5+/-13% higher systemic clearance (1.46+/-0.27 versus 1.38+/-0.25 l/h-kg), a 17+/-22% larger terminal volume of distribution (66.4+/-14 versus 57.2+/-10 l/kg) and a 9.7+/-26% longer terminal half-life (38+/-12 versus 34+/-10 h) (p < 0.05 for all comparisons). 3. The higher 2H8-toluene clearance may have been due to an increased rate of ring oxidation, consistent with the 17% higher observed fraction of 2H5- versus 1H5-cresol metabolites in urine. 4. The larger terminal volume and half-lives for 2H8-toluene suggested a higher adipose tissue/blood partition coefficient. 5. Observed isotope differences were small compared with interindividual differences in 1H8-toluene kinetics from previous studies. 6. The PBK model allowed us to ascribe observed isotope differences in solvent toxicokinetics to underlying physiologic mechanisms.
Collapse
Affiliation(s)
- C H Pierce
- Department of Environmental Health, University of Washington, Seattle 98195, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Narkiewicz K, van de Borne PJ, Cooley RL, Dyken ME, Somers VK. Sympathetic activity in obese subjects with and without obstructive sleep apnea. Circulation 1998; 98:772-6. [PMID: 9727547 DOI: 10.1161/01.cir.98.8.772] [Citation(s) in RCA: 329] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Obese humans are reported to have increased muscle sympathetic nerve activity (MSNA). Obstructive sleep apnea (OSA) may also be accompanied by increased MSNA. Because there is a high prevalence of OSA in obese humans, it is possible that high MSNA reported in obese subjects may in fact reflect the presence of OSA in these subjects. We tested the hypothesis that obesity, per se, in the absence of OSA, is not accompanied by increased MSNA. METHODS AND RESULTS We measured MSNA in 25 healthy normal-weight subjects and 30 healthy sedentary obese subjects. All subjects were screened by history and examination to exclude subjects with OSA or hypertension. OSA was further excluded by overnight polysomnographic studies. Despite careful screening, polysomnography revealed that 1 of 25 normal-weight subjects and 9 of 30 obese subjects had occult OSA (P=0.015). MSNA was similar in normal-weight subjects (41+/-3 bursts per 100 heartbeats) and obese subjects without sleep apnea (42+/-3 bursts per 100 heartbeats, P=0.99). MSNA in the 9 obese subjects with occult OSA was 61+/-8 bursts per 100 heartbeats, which was higher than MSNA in normal-weight subjects without sleep apnea (P=0.02) and higher than MSNA in obese subjects without sleep apnea (P=0.02). CONCLUSIONS Obesity alone, in the absence of OSA, is not accompanied by increased sympathetic activity to muscle blood vessels.
Collapse
Affiliation(s)
- K Narkiewicz
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, USA
| | | | | | | | | |
Collapse
|
25
|
Abstract
Several health hazards and social disabilities are associated with obesity. Increased mortality is associated with increased body weight. A high rate of mortality results from heart disease, diabetes mellitus, gallbladder disease, high blood pressure, and cancer. Physiologic cardiovascular changes occur, leading to left ventricular hypertrophy and lipid abnormalities. Hypertension, stroke, and venous stasis are increased. Pulmonary abnormalities include obstructive sleep apnea, which can be associated with secondary polycythemia and right ventricular hypertrophy. Gallstones, gallbladder disease, and accumulation of fat on the liver are significantly increased. Gout and reproductive abnormalities in women are common. Osteoarthritis of the knees and spine occur, although osteoporosis is rare. Risk for endometrial and breast cancer is increased, particularly in the presence of increased central fat. Changes in the skin include stretch marks, acanthosis negricans, hirsutism, intertrigo, and multiple papillomas. Impaired psychosocial function is manifested as social isolation, loss of job mobility, increased employee absenteeism, and economic and social discrimination.
Collapse
Affiliation(s)
- G A Bray
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| |
Collapse
|
26
|
Abstract
Fasting plasma insulin levels provide an indirect indication of insulin resistance. Glucose utilization rate, measured by the euglycemic clamp technique, is a direct measure of insulin sensitivity. Insulin sensitivity decreases with increasing body mass index (BMI) in the range of 27 to 35 kg/m2. A higher waist-to-hip ratio is associated with lower insulin sensitivity, after adjusting for BMI. Obese patients have higher plasma free fatty acid levels and less suppression of lipolysis by insulin than lean individuals. The increased supply of fatty substrates and their competition with glucose for oxidation constitute a component of insulin resistance in obesity. Both systolic and diastolic blood pressure are increased with BMI. The hemodynamic effects may be due to an increase in cardiac output and enhanced activity of the adrenergic nervous system.
Collapse
Affiliation(s)
- E Ferrannini
- CNR Institute of Clinical Physiology, University of Pisa, Italy
| |
Collapse
|