Obesity and the Microvasculature: A Systematic Review and Meta-Analysis

Background Overweight and obesity are thought to significantly influence a person's risk of cardiovascular disease, possibly via its effect on the microvasculature. Retinal vascular caliber is a surrogate marker of microvascular disease and a predictor of cardiovascular events. The aim of this systematic review and meta-analysis was to determine the association between body mass index (BMI) and retinal vascular caliber. Methods and Findings Relevant studies were identified by searches of the MEDLINE and EMBASE databases from 1966 to August 2011. Standardized forms were used for data extraction. Among over 44,000 individuals, obese subjects had narrower arteriolar and wider venular calibers when compared with normal weight subjects, independent of conventional cardiovascular risk factors. In adults, a 1 kg/m2 increase in BMI was associated with a difference of 0.07 μm [95% CI: −0.08; −0.06] in arteriolar caliber and 0.22 μm [95% CI: 0.21; 0.23] in venular caliber. Similar results were found for children. Conclusions Higher BMI is associated with narrower retinal arteriolar and wider venular calibers. Further prospective studies are needed to examine whether a causative relationship between BMI and retinal microcirculation exists.

[1]  P. Galan,et al.  Macrovascular and microvascular dysfunction in the metabolic syndrome , 2010, Hypertension Research.

[2]  I. Olkin,et al.  Meta-analysis of observational studies in epidemiology - A proposal for reporting , 2000 .

[3]  D. Altman,et al.  Measuring inconsistency in meta-analyses , 2003, BMJ : British Medical Journal.

[4]  Nish Chaturvedi,et al.  Determinants of Retinal Microvascular Architecture in Normal Subjects , 2009, Microcirculation.

[5]  J. J. Wang,et al.  Body mass index and its effects on retinal vessel diameter in 6-year-old children , 2007, International Journal of Obesity.

[6]  Luca Scalfi,et al.  Excess Body Weight and Incidence of Stroke: Meta-Analysis of Prospective Studies With 2 Million Participants , 2010, Stroke.

[7]  Neil M Bressler,et al.  Retinal arteriolar narrowing and risk of coronary heart disease. , 2003, Archives of ophthalmology.

[8]  Cong Sun,et al.  Retinal vascular caliber, blood pressure, and cardiovascular risk factors in an Asian population: the Singapore Malay Eye Study. , 2008, Investigative ophthalmology & visual science.

[9]  R. Klein,et al.  Prospective cohort study of retinal vessel diameters and risk of hypertension , 2004, BMJ : British Medical Journal.

[10]  Cecilia Becattini,et al.  Cardiovascular Risk Factors and Venous Thromboembolism: A Meta-Analysis , 2008, Circulation.

[11]  A. Giuliani,et al.  Effect of vascular risk factors on increase in carotid and femoral intima-media thickness. Identification of a risk scale. , 2011, Atherosclerosis.

[12]  R. Klein,et al.  Retinal microvascular abnormalities and incident stroke: the Atherosclerosis Risk in Communities Study , 2001, The Lancet.

[13]  R. Klein,et al.  Revised formulas for summarizing retinal vessel diameters , 2003, Current eye research.

[14]  Neil R. Powe,et al.  The Atherosclerosis Risk in Communities Study , 2006 .

[15]  Tien Yin Wong,et al.  Associations between the metabolic syndrome and retinal microvascular signs: the Atherosclerosis Risk In Communities study. , 2004, Investigative ophthalmology & visual science.

[16]  R. Klein,et al.  Retinal vascular caliber, cardiovascular risk factors, and inflammation: the multi-ethnic study of atherosclerosis (MESA). , 2006, Investigative ophthalmology & visual science.

[17]  Paul Mitchell,et al.  Retinal Vessel Diameters and Obesity: A Population‐Based Study in Older Persons , 2006, Obesity.

[18]  A. Kengne,et al.  Body mass index, waist circumference and waist–hip ratio: which is the better discriminator of cardiovascular disease mortality risk? Evidence from an individual‐participant meta‐analysis of 82 864 participants from nine cohort studies , 2011, Obesity reviews : an official journal of the International Association for the Study of Obesity.

[19]  T. Wong,et al.  Effect of blood pressure on the retinal vasculature in a multi-ethnic Asian population , 2009, Hypertension Research.

[20]  R. Klein,et al.  Retinal vascular abnormalities in persons with type 1 diabetes: the Wisconsin Epidemiologic Study of Diabetic Retinopathy: XVIII. , 2003, Ophthalmology.

[21]  R. Klein,et al.  Methods for evaluation of retinal microvascular abnormalities associated with hypertension/sclerosis in the Atherosclerosis Risk in Communities Study. , 1999, Ophthalmology.

[22]  R. Klein,et al.  Relative importance of systemic determinants of retinal arteriolar and venular caliber: the atherosclerosis risk in communities study. , 2008, Archives of ophthalmology.

[23]  T. Wong,et al.  Retinal vascular caliber: systemic, environmental, and genetic associations. , 2009, Survey of ophthalmology.

[24]  F. Hu,et al.  Association of overweight with increased risk of coronary heart disease partly independent of blood pressure and cholesterol levels: a meta-analysis of 21 cohort studies including more than 300 000 persons. , 2007, Archives of internal medicine.

[25]  R. Klein,et al.  Meta-analysis: Retinal Vessel Caliber and Risk for Coronary Heart Disease , 2009, Annals of Internal Medicine.

[26]  Erdahl T. Teber,et al.  Effect of obesity on retinal vascular structure in pre-adolescent children. , 2011, International journal of pediatric obesity : IJPO : an official journal of the International Association for the Study of Obesity.

[27]  R. Klein,et al.  Retinal arteriolar narrowing and risk of coronary heart disease in men and women. The Atherosclerosis Risk in Communities Study. , 2002, JAMA.

[28]  A. Hofman,et al.  Are retinal arteriolar or venular diameters associated with markers for cardiovascular disorders? The Rotterdam Study. , 2004, Investigative ophthalmology & visual science.

[29]  J. Panza,et al.  Increased Activity of Endogenous Endothelin in Patients With Type II Diabetes Mellitus , 2002, Circulation.

[30]  J. Mintz,et al.  Obesity augments vasoconstrictor reactivity to angiotensin II in the renal circulation of the Zucker rat. , 2007, American journal of physiology. Heart and circulatory physiology.

[31]  C. Stehouwer,et al.  Impaired Microvascular Function in Obesity: Implications for Obesity-Associated Microangiopathy, Hypertension, and Insulin Resistance , 2004, Circulation.

[32]  Jefferson C Frisbee,et al.  Obesity and vascular dysfunction. , 2008, Pathophysiology : the official journal of the International Society for Pathophysiology.

[33]  S. Panico,et al.  A paraoxonase gene polymorphism, PON 1 (55), as an independent risk factor for increased carotid intima-media thickness in middle-aged women. , 2003, Atherosclerosis.

[34]  D. Stepp,et al.  Oxidant stress-induced increase in myogenic activation of skeletal muscle resistance arteries in obese Zucker rats. , 2002, American journal of physiology. Heart and circulatory physiology.

[35]  E. Barrett,et al.  Obesity Blunts Insulin-Mediated Microvascular Recruitment in Human Forearm Muscle , 2006, Diabetes.

[36]  M. Sturek,et al.  Mechanisms of Coronary Dysfunction in Obesity and Insulin Resistance , 2007, Microcirculation.

[37]  R. Hester,et al.  Regulation of Muscle Blood Flow in Obesity , 2007, Microcirculation.

[38]  J. Staessen,et al.  Obesity is associated with increased arterial stiffness from adolescence until old age , 2005, Journal of hypertension.

[39]  Ronald Klein,et al.  Retinal vascular caliber in persons with type 2 diabetes: the Wisconsin Epidemiological Study of Diabetic Retinopathy: XX. , 2006, Ophthalmology.

[40]  Sébastien Czernichow,et al.  Microvascular dysfunction in healthy insulin-sensitive overweight individuals , 2010, Journal of hypertension.

[41]  R. Klein,et al.  Prediction of incident stroke events based on retinal vessel caliber: a systematic review and individual-participant meta-analysis. , 2009, American journal of epidemiology.

[42]  Paul Mitchell,et al.  BMI and Retinal Vascular Caliber in Children , 2007, Obesity.

[43]  C. Papamichael,et al.  Impact of Obesity in Intima Media Thickness of Carotid Arteries , 2006, Obesity.

[44]  Lee-Yang Wong,et al.  Polyfluoroalkyl compounds in pooled sera from children participating in the National Health and Nutrition Examination Survey 2001-2002. , 2009, Environmental science & technology.