Correlations between surrogate measures of insulin resistance and cardiovascular risk factors in obese and overweight patients

There are different equations to estimate insulin sensitivity by using OGTT with a reasonable approximation to whole body sensitivity obtained with the glucose clamp. Further work is needed to address their role in clinical practice as markers of the metabolic syndrome and predictors for cardiovascular disease. In the present study, we determined plasma glucose and insulin values during an OGTT test in 144 overweight and obese individuals. We assessed insulin resistance by the use of different equations and established their relationship with cardiovascular risk factors associated to the insulin resistance syndrome. Distributed the patients by quintiles of body mass index (BMI), the different surrogate measures clearly demonstrated that the more obese individuals were the most insulin resistant, a similar but not significant trend was observed related to the other cardiovascular risk factors. Efforts to use both fasting and post-load glucose and insulin concentrations to create indexes for routine use in clinical practice do not seem to be particularly useful in overweight or obese patients, as most of these patients will be insulin-resistant and insulin resistance is closely linked but not equal to the metabolic syndrome.     

青少年腰围与代谢综合征相关性分析

目的 探讨青少年腰围与代谢综合征(MS)之间的关系.方法 选取2006年河北省秦皇岛市流行病学调查中检出的18岁腹型肥胖青少年49例,随机选取同期18岁腹围正常青少年49名,测量所有入选者的身高、体重、腰围、血压、空腹血糖(FPG)、三酰甘油(TG)、胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)及低密度脂蛋白胆固醇(LDL-C),比较两组MS检出率,分析腰围与MS的关系.结果 腹型肥胖组中MS检出6例(12.2%).腹型肥胖组95.9%存在至少1种MS组分.男女腹型肥胖组青少年体重、体重指数(BMI)、收缩压(SBP)、舒张压(DBP)、TG明显升高,HDL-C明显下降.超重肥胖、高血压、高SBP、高DBP、高TG和低HDL-C检出率均明显高于对照组.腰围与BMI(r=0.694)、体重(r=0.878)、SBP(r=0.508)、DBP(r=0.391)、LDL-C(r=0.398)呈显著正相关(P＜0.05).结论 腹型肥胖与MS密切相关,腰围测量有助于青少年MS筛查.     

Associations between periodontal disease and cardiovascular surrogate measures among Indigenous Australians

Background/objectives

Inflammation is a key pathogenetic factor in atherogenesis. Periodontitis is a chronic inflammatory source which can have systemic impacts. Indigenous Australians have a higher prevalence of periodontal disease and experience cardiovascular disease earlier than non-Indigenous Australians. The aim was to describe the association between severity of periodontal inflammatory disease and measures of arterial structure and function.

Methods

Periodontal disease in a convenience sample of Indigenous Australians was assessed clinically; for those with periodontal disease, the extent of periodontal pockets ≥ 4 mm was stratified into quartiles. Vascular health was measured non-invasively via carotid-dorsalis pedis pulse-wave velocity (PWV), and via B-mode ultrasound of the common carotid intima-media (IMT). Non-fasting blood samples were collected for lipid and inflammatory marker evaluation. Linear regression models were constructed to determine the associations between extent of periodontal pocketing and vascular health, adjusting for traditional cardiovascular common risk factors.

Results

273 Indigenous Australian adults were recruited and complete data was available for 269 participants (154 males), median age 39 years. Arterial stiffness (PWV) significantly increased with increasing extent of periodontal pocketing (p trend = 0.001). By contrast, carotid IMT did not differ across quartiles.

Conclusions

Periodontal pocketing was associated with central arterial stiffness, a marker of presymptomatic arterial dysfunction, in Indigenous Australian adults with periodontal disease.     

The metabolic syndrome, insulin resistance, and cardiovascular risk in diabetic and nondiabetic patients

CONTEXT: The contribution of insulin resistance per se to the vascular risk conferred by the metabolic syndrome (MetS) is not known; conversely, it is uncertain whether insulin resistance confers vascular risk beyond the entity of the MetS. OBJECTIVE: The objective of this study was to investigate the impact of the MetS (Adult Treatment Panel III criteria) and insulin resistance (as estimated by the homeostasis model assessment index) on the incidence of vascular events. DESIGN AND PATIENTS: This was a prospective cohort study enrolling 750 consecutive patients undergoing coronary angiography for the evaluation of coronary artery disease. SETTING: The study was performed at a tertiary care clinical research center. MAIN OUTCOME MEASURE: The main outcome measure was the incidence of vascular events over 2.3 yr. RESULTS: Both the MetS and insulin resistance predicted vascular events after controlling for non-MetS risk factors [hazard ratio (HR), 2.74 (95% confidence interval, 1.71-4.39; P < 0.001) and 1.51 (1.24-1.84; P < 0.001), respectively]. After additional adjustment for insulin resistance, the MetS remained significantly predictive of vascular events [HR, 2.69 (1.57-4.64); P < 0.001], and conversely, insulin resistance remained significantly predictive of vascular events despite adjustment for the MetS [standardized HR, 1.41 (1.14-1.75); P = 0.002]. Additional adjustment for the presence of type 2 diabetes revealed that both the MetS [adjusted HR, 2.57 (1.47-4.51); P = 0.001] and homeostasis model assessment of insulin resistance [standardized adjusted HR, 1.37 (1.09-1.73); P = 0.007] significantly predicted vascular events independent from diabetes status. CONCLUSIONS: Both the MetS and insulin resistance are strong and mutually independent predictors of vascular risk among angiographed coronary patients.     

腰围、BMI与胰岛素抵抗指数的相关性

目的探讨腰围（WC）和5种胰岛素抵抗（IR）及敏感性指数间的相关性,并与BMI进行比较分析。方法2456例研究对象分为2型糖尿病（DM）组、糖调节受损（IGR）组和正常糖耐量（NGT）组,比较WC、BMI和5种指数相关性在3组的差异。结果WC、BMI与5种指数均相关（P〈0.05）,与lgISI2的相关性较其他指数强（beta分别为-0.1581和-0.592）;不同糖代谢各组比较,WC与各指数间的相关DM组〉NGT组〉IGR组,BMI与各指数间的相关性随糖调节异常的加重而增强。结论WC、BMI均是评估IR及敏感性的良好指标,而WC更适于对NGT人群IR的评估。     

Association between insulin resistance and metabolic syndrome risk factors in Japanese

Aims/Introduction: It is important to identify individuals at risk of metabolic syndrome (MetS), namely those with insulin resistance. Therefore, the aim of the present study was to find anthropometric and metabolic parameters that can better predict insulin resistance. Subjects and Methods: We selected 3899 individuals (2058 men and 1841 women), excluding those with fasting plasma glucose (FPG) ≥126 mg/dL, on medication for hypertension, dyslipidemia or diabetes, and those with a history of advanced macrovascular disease. Using multivariate analyses, we selected components for obesity, lipids, and blood pressure based on the strength of their association with the homeostasis model assessment of insulin resistance (HOMA‐IR). Results: In multiple linear regression analysis, body mass index (BMI), waist circumference (WC), triglycerides (TG), high‐density lipoprotein–cholesterol (HDL‐C), and systolic blood pressure (SBP) were selected in men and women, and the effect of BMI on HOMA‐IR outweighed that of WC. In multiple logistic regression analysis, BMI, TG, and SBP were significantly associated with HOMA‐IR ≥2.5 in both genders, but WC and HDL‐C were only selected in men. Combinations of BMI, TG, SBP, and FPG showed higher HOMA‐IR values than those of the existing MetS components, considered useful for the identification of individual with higher insulin resistance. Conclusions: Body mass index, TG and SBP were selected as components significantly related to insulin resistance. The selected components were fundamentally adherent to the existing MetS criteria, the only difference being the measure of obesity, in which a stronger association with insulin resistance was observed for BMI than WC. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00162.x, 2011)     

The association between the hypertriglyceridaemia waist phenotype,cardiovascular risk factors and the metabolic syndrome in South African Asian-Indians

Background and aimsThe combination of high triglycerides and increased waist circumference (HTGW) has not been examined as a predictor of cardiometabolic abnormalities or the metabolic syndrome (MetS) in high-risk Asian populations. This study examines the so-called hypertriglyceridemia waist (HTGW) phenotype, (high serum triglycerides [Tg]) and increased waist circumference (WC) as a predictor of cardiometabolic abnormalities in a high-risk Asian population.MethodsData from the Phoenix Lifestyle Project, a cross-sectional study of 1349 South Asian Indians (15–65 years; 379 men; 970 women) in Durban, KwaZulu-Natal, were reclassified into different waist and Tg phenotypes using the demographic, anthropometric, and biochemical parameters. The HTGW phenotype was defined as WC ≥ 90 cm for men; ≥80 cm for women & TG ≥ 1.7 mmol/L. The MetS was determined using the harmonised criteria. Stepwise logistic regression was used to determine the strength of each phenotype as a predictor of the MetS.ResultsThe HTGW phenotype was recorded in 35.4% of participants, predominantly women (36.1%) and 8.2% smokers. Metabolic derangements and cardiovascular risk factors increased significantly in those with HTGW phenotype. After adjustment, multivariate logistic regression showed that the association between elevated total serum cholesterol, LDL, lowered HDL, diabetes and hypertension with HTGW persisted. The odds for participants with the HTGW phenotype developing the MetS was 19.7 (95% CI 13.9; 27.9). The degree of concordance between the HTGW was highest with the IDF and harmonised criteria for MetS.ConclusionThe HTGW phenotype was associated with a significantly higher risk of developing additional lipid derangements, hypertension, diabetes and the MetS.     

体重指数和腰围与代谢综合征发生风险的比较研究

目的 比较体重指数、腰围与代谢综合征发生风险的相关性.方法 554例人选者(男316例,女238例),按照体重指数和腰围被分为周围肥胖组192例、腹部肥胖组135例和混合肥胖组237例,7年后进行随访.结果 共随访到520例.周围肥胖组代谢综合征累积发生率26.3%(49/186),腹部肥胖组代谢综合征累积发生率41.7%(50/120),混合肥胖组代谢综合征累积发生率43.0%(92/214).腹部肥胖组和混和肥胖组代谢综合征累积发生率显著高于周围肥胖组(X2分别为7.825和12.082,均P＜0.01),且基线时舒张压、甘油三酯、空腹血糖、空腹胰岛素及稳态模型评估法胰岛素抵抗指数(HOMA-IR)也显著高于前者(均P＜0.05).以有或无代谢综合征分组后基线资料比较,代谢综合征组无论男女,腰围和腰臀比均高于非代谢综合征组(P＜0.01和P＜0.05),体重指数在两组无统计学差异,并且代谢综合征组空腹血糖、空腹胰岛素和HOMA-IR显著高于非代谢综合征组(均P＜0.05).Logistic回归显示,与代谢综合征发生风险相关的因素主要为腰围(P=0.021)、腰臀比(P=0.009)、HOMA-IR(P=0.004).结论 腹部脂肪堆积及胰岛素抵抗是代谢综合征发生的两个重要因素,腰围比体重指数与代谢综合征的发生风险关系更密切.     

Polycystic ovary syndrome, metabolic syndrome, cardiovascular risk and the role of insulin sensitizing agents

The Polycystic Ovary Syndrome (PCOS) affects 6 to 10% of women of childbearing age. Insulin resistance and hyperinsulinemia are present in nearly all PCOS patients and play a central role in the development of both hyperandrogenism and metabolic syndrome (MS). MS occurs in approximately 43% of PCOS patients, raising the cardiovascular risk to up seven fold in these patients. Several serum, functional and structural markers of endothelial dysfunction and subclinical atherosclerosis were described in PCOS patients, even those young and non-obese. However, despite the fact that PCOS adversely affects the cardiovascular profile, long-term studies did not demonstrate a consistent raise in cardiovascular mortality, which seems to be more observed in the post-menopausal period. Recently, oral contraceptives are being substituted for insulin sensitizing agents (metformin and glitazones) in the PCOS treatment, due to their effects on insulin resistance and cardiovascular risk.     

Adiponectin and its gene variants as risk factors for insulin resistance, the metabolic syndrome and cardiovascular disease

The increasing prevalence of obesity and metabolic syndrome/insulin resistance has attracted considerable interest due to their identification as risk factors for cardiovascular disease and, hence, targets for cardiovascular disease prevention. This review focuses on adiponectin, the most profusely secreted protein from adipose tissue, which itself is being increasingly recognised as an important and very active endocrine organ, secreting a wide range of biologically active substances known as adipokines or adipocytokines. Adiponectin has been demonstrated to have insulin sensitising effects, and secretion of adiponectin is reduced as adipose tissue mass increases. Adiponectin has also been demonstrated to have anti-inflammatory and anti-atherogenic properties, and is independently associated with cardiovascular disease. The evidence that suggests adiponectin plays a role in the relationship between obesity and insulin resistance, and also insulin resistance and cardiovascular disease, is examined. Variation in the adiponectin gene is one tool to determine whether this relationship is causal. The association of identified variants with human disease, specifically obesity and its consequences, type 2 diabetes and cardiovascular disease is reviewed. This data may enable patients at greater risk of the adverse effects of obesity to be identified and, as such, benefit from more targeted therapy of its consequences.     

Optimal cut‐off point of waist circumference for the diagnosis of metabolic syndrome in Japanese subjects

Metabolic syndrome (MetS) has been redefined by a new criterion in Japan, in which waist circumference cut‐off points, that is 85 cm for men and 90 cm for women, are used; however, objections are rising against this criterion. The present study examined the criterion for waist circumference to predict the accumulation of the components of MetS. In the present study, we used data for 5972 Japanese people who received annual health examinations, and 621 men (16.3%) and 51 women (2.4%) were diagnosed as having MetS. A cut‐off point as a predictor for two or more components of MetS was evaluated by the sensitivity/specificity and a receiver operating characteristic analysis. The optimal point of waist circumference was estimated as being approximately 84 cm for men and 80 cm for women. We therefore recommend revising the cut‐off value for the criterion of MetS in women according to our results and studies from other investigators. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00020.x, 2010)     

Utility of obesity and metabolic dyslipidemia (a non‐insulin based determinate of the metabolic syndrome and insulin resistance) in predicting arterial stiffness

Increased arterial stiffening is not only a hallmark of the aging process but the consequence of many metabolic abnormalities such as insulin resistance (IR), obesity, and metabolic dyslipidemia. In patients with the cardiometabolic syndrome, arterial stiffening is consistently observed across all age groups. A core feature linking obesity and the metabolic syndrome to arterial stiffness has been IR. However, including other metabolic abnormalities such as metabolic dyslipidemia increases the risk prediction of arterial stiffness in a dose‐dependent fashion. Chronic hyperinsulinemia also increases the activity of both the systemic and the local RAAS which contributes to the development of arterial stiffness. All of these relevant metabolic features that predict arterial stiffness are appropriately incorporated in the METS‐IR used in the current study.     

Assessment of insulin resistance using surrogate markers in patients of metabolic syndrome

BackgroundInsulin resistance is defined as situation where there is insufficient biological or metabolic response to normal plasma levels of insulin. For precise quantification of insulin sensitivity, the euglycemic hyperinsulinemic clamp may be used, but it is expensive, invasive and used mainly in research settings. HOMA-IR (Homeostasis Model Assessment-Insulin Resistance) and ISI 0,120 (Insulin Sensitivity Index) are indirect markers of insulin resistance. The present study evaluated the usefulness of the surrogate markers for evaluation of Insulin resistance in clinical settings.MethodThis study was carried out on 120 subjects. Of these, 60 subjects presenting with two or more features of metabolic syndrome (Hypertension, Obesity, Dyslipidemia, altered glucose tolerance) were included in the study group. Sixty age and sex matched healthy controls were selected with normal Body mass index. All the subjects underwent a standard Oral Glucose Tolerance Test. Plasma glucose and serum insulin were estimated using Glucose oxidase and ELISA principle respectively. HOMA-IR and ISI 0,120 were calculated using relevant formulae.ResultThe HOMA-IR values were significantly raised in suspected Insulin resistant subjects (6.74 ± 1.24) as compared to healthy controls (0.82 ± 0.017) (p = 0.001). ISI 01,20 was significantly low in insulin resistant subjects (3.13 ± 0.17) as compared to controls (20.60 ± 0.37) (p < 0.001). Insulin sensitivity index showed a significant negative correlation with HOMA-IR. A significant negative correlation was observed between serum cholesterol, serum LDL-cholesterol and ISI 0,120 indicating that dyslipidemia in metabolic syndrome may result from a decrease in Insulin sensitivity.ConclusionHOMA-IR and ISI 0,120 are simple, convenient and sensitive estimates of insulin resistance adaptable for use in clinical practice as well as large-scale epidemiological studies.     

Discordance between insulin resistance and metabolic syndrome: features and associated cardiovascular risk in adults with normal glucose regulation

The aims of this study were to investigate the extent of concordance between metabolic syndrome (MS) and insulin resistance (IR), the features of discordance, and the magnitude of their independent association with cardiovascular disease (CVD) risk. After exclusion of individuals with diabetes and impaired fasting glucose, the population sample of 1534 men and women, representative of Turkish adults (mean age, 52.2 years), were evaluated cross-sectionally and at a mean 2 years' follow-up. Metabolic syndrome was identified by criteria of the Adult Treatment Panel III, except for male waist circumference (>94 cm). Insulin resistance was defined by the upper quartile in the sample (>2.245) of the homeostatic model assessment (HOMA) index. Clinical fatal and nonfatal CVD existed or developed in 165 subjects. Waist circumference proved to be by far the strongest significant determinant of HOMA in both sexes, followed by triglycerides. The cohort was categorized into 4 by the presence or absence of MS and IR. Each of the latter represented 34% and 25%, but together constituted 45% of the sample, thus disclosing concordance in a third of the conditions combined. The nonconcordant IR/NoMS group was less common than the MS/NoIR group and was distinct from the latter in having significantly lower waist girth, blood pressure, apolipoprotein B and triglyceride levels, and higher high-density lipoprotein cholesterol, glucose, and insulin levels and physical activity in both sexes. When adjusted for 5 important risk factors, although the excess risk in men with MS failed to attain significance, men with IR were associated with a significant 1.9-fold CVD risk. The IR/NoMS group had a 2.2-fold (95% confidence interval, 0.97-5.11) CVD likelihood compared with the large insulin-sensitive group, after adjustment for age, sex, log C-reactive protein, low-density lipoprotein cholesterol, smoking status, physical activity, and the 2 groups of MS with or without IR. Overlapping between MS and IR is limited in either sex, and MS/NoIR is more common than IR/NoMS. Overall, IR is more significantly associated with CVD risk than MS in men and in both sexes after adjustment for important confounders. Insulin resistance without MS tends to implicate in middle-aged and elderly Turkish men roughly a 2-fold CVD risk, corresponding to 50% excess risk per 1 SD in HOMA index, independent of MS and important covariates.     

血清补体3与代谢综合征及胰岛素抵抗关系研究

目的探讨血清补体3（C3）与代谢综合征（MS）及其组分,以及胰岛素抵抗（IR）的关系。方法96例MS患者和141例非MS患者用免疫比浊法检测血清C3,同时检测BMI、血糖、血压、血脂。结果MS患者血清C3水平明显高于非MS患者,且C3水平随MS组分的增加而升高（P〈0．01）。相关分析显示血清C3浓度与BMI、SBP、FPG、TC、TG、HOMA—IR呈正相关。结论血清C3水平与MS组分相关,与IR有关。     

The relationship between waist circumference and metabolic risk factors: cohorts of European and Chinese descent

Waist circumference (WC) may be the best anthropometric index for identifying individuals at risk for cardiovascular disease (CVD) and diabetes mellitus (DM). The objectives of this study were to determine if the relationship between WC and metabolic risk factors is similar in men and women of Chinese and European descent, and to assess the effect of ethnicity on these relationships. Apparently healthy men and women of Chinese (n = 92) and European (n = 99) descent were recruited from hospital staff and assessed for anthropometric variables and blood pressure (BP), lipids, insulin, and glucose. The study cohort was stratified by sex, and regression analyses were performed with the various metabolic risk factors as the outcome and WC and ethnicity as predictors. Chinese men and women had significantly lower WC than European men and women. Age and metabolic risk factors were similar between the 2 ethnic groups except for BP. Metabolic risk factors significantly correlated with WC within each gender and ethnic cohort. In men, ethnicity was an independent predictor for total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and the ratio of TC to high-density lipoprotein cholesterol (HDL-C) after controlling for WC. In women, ethnicity significantly interacted with WC as an independent predictor of TG, TC:HDL-C ratio, insulin, and glucose. As ethnic descent modifies the relationship between WC and metabolic risk factors, current WC targets derived from relationships in European populations are not applicable to Chinese men and women. Therefore, ethnic background should be considered when using WC as a marker of cardiovascular risk.     

Comparison of waist circumference versus body mass index in diagnosing metabolic syndrome and identifying apparently healthy subjects at increased risk of cardiovascular disease

The goal of this study was to compare the impact of differences in waist circumference (WC) defined according to the International Diabetes Federation (IDF) and the Adult Treatment Panel III (ATP III) and body mass index (BMI) on cardiovascular disease risk factors in 402 apparently healthy volunteers of European ancestry. Consequently, measurements were made of the WC, BMI, blood pressure, glucose, and lipid components of metabolic syndrome (MS) and insulin-mediated glucose uptake. Subjects were divided according to WC (IDF and ATP III criteria) and by normal weight, overweight, or obesity using BMI, and comparisons were made of the effect of these different indexes of adiposity on cardiovascular disease risk factors. The results indicated that WC and BMI significantly correlated (p <0.001) and were associated with differences in insulin-mediated glucose uptake to a similar degree in men (r = 0.57 and r = 0.59) and women (r = 0.53 and r = 0.52). Prevalences of MS were essentially identical irrespective of the measure of WC used (ATP III vs IDF), as were metabolic characteristics of those classified using IDF or ATP III criteria. Cardiovascular disease risk factor status did not vary substantially when subjects were divided on the basis of WC or BMI. In conclusion, prevalences of MS or cardiovascular disease risk factors did not vary as a function of differences in IDF and ATP III criteria for WC. BMI identified individuals at increased cardiovascular disease risk as effectively as determination of WC.