Metabolic clustering of risk factors: evaluation of Triglyceride-glucose index (TyG index) for evaluation of insulin resistance

Background

Metabolic syndrome over the years have structured definitions to classify an individual with the disease. Literature review suggests insulin résistance is hallmark of these metabolic clustering. While measuring insulin resistance directly or indirectly remains technically difficult in general practice, along with multiple stability issues for insulin, various indirect measures have been suggested by authorities. Fasting triglycerides-glucose (TyG) index is one such marker, which is recently been suggested as a useful diagnostic marker to predict metabolic syndrome. However, limited data is available on the subject with almost no literature from our region on the subject.

Objective

1. To correlate TyG index with insulin resistance, anthropometric indices, small dense LDLc, HbA1c and nephropathy. 2. To evaluate TyG index as a marker to diagnose metabolic syndrome in comparison to other available markers.

Design-cross-sectional analysis

Place and duration of study-From Jun-2016 to July-2017 at PSS HAFEEZ hospital Islamabad.

Subjects and methods

From a finally selected sample size of 227 male and female subjects we evaluated their anthropometric data, HbA1c, lipid profile including calculated sdLDLc, urine albumin creatinine raito(UACR) and insulin resistance (HOMAIR). TyG index was calculated using formula of Simental-Mendía LE et al. Aforementioned parameters were correlated with TyG index, differences between subjects with and without metabolic syndrome were calculated using Independent sample t-test. Finally ROC curve analysis was carried out to measure AUC for candidate parameters including TyG Index for comparison.

Results

TyG index in comparison to other markers like fasting triglycerides, HOMAIR, HDLc and non-HDLc demonstrated higher positive linear correlation with BMI, atherogenic dyslipidemia (sdLDLc), nephropathy (UACR), HbA1c and insulin resistance. TyG index showed significant differences between various markers among subjects with and without metabolic syndrome as per IDF criteria. AUC (Area Under Curve) demonstrated highest AUC for TyG as [(0.764, 95% CI 0.700–0.828, p-value?≤?0.001)] followed by fasting triglycerides [(0.724, 95% CI 0.656–0.791, p-value?≤?0.001)], sdLDLc [(0.695, 95% CI 0.626–0.763, p-value?≤?0.001)], fasting plasma glucose [(0.686, 95% CI 0.616–0.756, p-value?≤?0.001)], Non-HDLc [(0.640, 95% CI 0.626–0.763, p-value?≤?0.001)] and HOMAIR [(0.619, 95% CI 0.545–0.694, p-value?≤?0.001)].

Conclusion

TyG index, having the highest AUC in comparison to fasting glucose, triglycerides, sdLDLc, non-HDLc and HOMAIR can act as better marker for diagnosing metabolic syndrome.

     

简易胰岛素抵抗指数对类风湿关节炎患者胰岛素抵抗的评估价值

目的:利用空腹甘油三酯及葡萄糖简易指数（TyG）评估类风湿关节炎（RA）患者中的胰岛素抵抗（IR）,并探讨RA患者IR的相关因素。方法:选取2019年1月至12月新疆维吾尔自治区人民医院风湿免疫科未使用激素的RA患者177例,根据病程长短分为极早期RA（病程<6月）共45例,早期RA（病程6个月至2年）共64例,非早期...     

男性老年人胰岛素抵抗指数与胰岛素分泌曲线的对照分析

目的对比研究男性老年人胰岛素抵抗指数与胰岛素分泌曲线,探讨其在反映胰岛素抵抗的运用价值。方法根据体重指数将体检患者分为肥胖组与非肥胖组,测空腹血糖（FBG）、甘油三脂（TG）、胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）,并进行葡萄糖耐量试验（OGTT）、胰岛素释放试验（IRT）;计算胰岛素抵抗指数（HOMA-IR）。结果两组间的年龄、FBG、FINS、HOMA-IR、TC等指标以及两组间OGTT血糖变化曲线无显著性差异（P〉0.05）;肥胖组TG、LDL-C高于非肥胖组,HDL-C低于非肥胖组;肥胖组餐后1小时、2小时的胰岛素水平明显高于非肥胖组（P〈0.01）。结论高胰岛素血症首先出现在餐后,餐后高胰岛素血症比胰岛素抵抗指数更为敏感地反映胰岛素抵抗。     

TyG指数在中青年人群中的冠心病预测价值

目的：评估甘油三酯葡萄糖乘积指数（TyG指数）对中青年人群冠心病及冠状动脉狭窄程度的预测价值。方法：回顾性纳入2019年10月-2020年4月在安徽医科大学第三附属医院心内科住院并首次行冠状动脉造影检查的224名年龄＜60周岁的患者。收集所有入组患者的临床资料、实验室检查数据。根据冠脉造影结果,将入组患者分为冠心病组(CAD组)116例及无冠心病组(NCAD组)108例。另根据Gensini评分的三分位数水平将116例冠心病组患者分为低分组（36例）、中间分组（42例）和高分组（38例）。比较各组间临床资料的差异,运用 Logistic回归分析及 ROC曲线评估TyG指数对中青年冠心病及冠状动脉狭窄程度的预测价值。结果：Spearman相关性分析显示,TyG指数与冠脉Gensini评分呈正相关（r=0.513,P<0.001）。Logistic多因素回归分析显示高血压、HDL-C、TyG指数是中青年冠心病的独立危险因素。R0C曲线分析显示,TyG指数预测高Gensini评分的曲线下面积为0.824（95% Cl 0.772-0.869,P<0.01）。结论：TyG指数是中青年人群冠心病发病的独立危险因素,并与冠状动脉的狭窄程度呈正相关。     

A novel surrogate index for hepatic insulin resistance

Aims/hypothesis  

In epidemiological and genetic studies surrogate indices are needed to investigate insulin resistance in different insulin-sensitive tissues. Our objective was to develop a surrogate index for hepatic insulin resistance.     

A lipid-parameter-based index for estimating insulin sensitivity and identifying insulin resistance in a healthy population

AIM: Insulin resistance needs to be identified as early as possible in its development to allow targeted prevention programmes. Therefore, we compared various fasting surrogate indices for insulin sensitivity using the euglycaemic insulin clamp in an attempt to develop the most appropriate method for assessing insulin resistance in a healthy population. METHODS: Glucose, insulin, proinsulin, glucagon, glucose tolerance, fasting lipids, liver enzymes, blood pressure, anthropometric parameters and insulin sensitivity (Mffm/I) using the euglycaemic insulin clamp were obtained for 70 normoglycaemic non-obese individuals. Spearman's rank correlations were used to examine the association between Mffm/I and various fasting surrogate indices of insulin sensitivity. A regression model was used to determine the weighting for each variable and to derive a formula for estimating insulin resistance. The clinical value of the surrogate indices and the new formula for identifying insulin-resistant individuals was evaluated by the use of receiver operating characteristic (ROC) curves. RESULTS: The variables that best predicted insulin sensitivity were the HDL-to-total cholesterol ratio, the fasting NEFA and fasting insulin. The use of the lipid-parameter-based formula Mffm/I=12x[2.5x(HDL-c/total cholesterol)-NEFA] - fasting insulin appeared to have high clinical value in predicting insulin resistance. The correlation coefficient between Mffm/I and the new fasting index was higher than those with the most commonly used fasting surrogate indices for insulin sensitivity. CONCLUSION: A lipid-parameter-based index using fasting samples provides a simple means of screening for insulin resistance in the healthy population.     

脂联素/瘦素与胰岛素抵抗指数的相关性

目的研究健康人群、肥胖和2型糖尿病(T2DM)患者的血清脂联素/瘦素(APN/LEP)与胰岛素抵抗指数的关系。方法采用病例对照研究,2型糖尿病伴有肥胖组(DO)42例,T2DM不伴肥胖组(NDO)42例,单纯性肥胖组(OB)37例,正常对照组(NC)28名。检洲了4组研究对象血脂、血糖(FBG)、空腹胰岛素(Fins)、APN、LEP水平,用HOMA模型公式计算胰岛素抵抗指数(HOMA-IR)。结果正常对照组(NC)的脂联素/瘦素明显大于其它三组,统计学检验差异有显著性意义(P0.05),而其它三组间的脂联素/瘦素差异无显著性意义。糖尿病肥胖组(DO)的HOMA-IP明显高于其它三组,统计学检验差异有显著性意义(P0.05)。随着脂联素/瘦素的降低,胰岛素抵抗指数呈上升趋势。结论胰岛素抵抗指数与脂联素/瘦素间呈显著负相关,脂联素/瘦素有望成为反映胰岛素抵抗的新指标。     

社区非糖尿病人群血压水平与稳态模型胰岛素抵抗指数及定量胰岛素敏感性指标的相关性研究

目的 探讨社区非糖尿病人群血压测值与稳态模型胰岛素抵抗指数(HOMA-IR)及定量胰岛素敏感性指标(QUICKI)的相关性.方法 2002年8月至2004年3月,在上海交通大学医学院附属仁济医院内分泌科对上海浦东上钢和塘桥社区居民743名(除外糖尿病和糖耐量受损、继发性高血压及有严重肝、肾功能损害者)进行研究检测.以标准法测量血压、身高、体重、腰围和臀围.根据不同血压测值分为非高血压组和高血压组.非高血压组包括(1)理想血压组,收缩压＜120 mm Hg(1 mm Hg=0.133 kPa),舒张压＜80 mm Hg;(2)正常血压组收缩压120～＜130 mm Hg,舒张压80～＜85 mm Hg;(3)正常高值血压组收缩压130～＜140 mm Hg,舒张压85～＜90 mm Hg.高血压组收缩压≥140 mm Hg和(或)舒张压≥90 mm Hg.放免法测定空腹血浆胰岛素,并计算HOMA-IR及QUICKI.采用SPSS 11.5软件进行统计分析.结果 社区743名非糖尿病人群中,正常高值血压组和高血压组与理想血压组之间HOMA-IR及QUICKI比较差异均有显著性意义(P＜0.01).血压值与年龄、体重指数(BMI)、腰围、WHR、空腹胰岛素、血浆总胆固醇、三酰甘油及HOMA-IR呈正相关,与QUICKI呈负相关.在控制年龄及性别之后,HOMA-IR及QUICKI和血压之间仍明显相关(P＜0.001).结论 HOMA-IR和QUICKI指数均是预测正常高值血压人群胰岛素抵抗的独立影响因子.治疗早期高血压,减轻胰岛素抵抗的因素可能更重要.     

急性心肌梗死患者TyG指数与冠状动脉病变严重程度的相关性

目的]探讨急性心肌梗死(AMI)患者甘油三酯-葡萄糖(TyG)指数与冠状动脉病变严重程度的相关性。 [方法]回顾性选择2020年1月─2023年3月期间就诊于新疆医科大学第四附属医院确诊为AMI的424名患者作为研究对象,收集临床资料及冠状动脉造影(CAG)结果,Gensini评分用以定量评估冠状动脉病变程度。根据Gensini评分三分位法分为低Gensini评分组(＜45分,n＝140)、中Gensini评分组(45～86分,n＝143)和高Gensini评分组(≥87分,n＝141)。采用单因素和多因素Logistic回归模型分析TyG指数与高Gensini评分冠状动脉病变发生的关系;采用Spearman相关分析法分析TyG指数与AMI患者Gensini评分之间的相关性;采用ROC曲线分析TyG指数对冠状动脉病变严重程度的预测价值。 [结果]高Gensini评分组TyG指数较低、中Gensini评分组明显升高(P＜0.05)。Logistic回归分析显示,TyG指数为AMI患者严重冠状动脉病变发生的独立危险因素(OR＝13.327,95%CI:2.642～67.235,P＝0.002)。Spearman相关分析显示,TyG指数与冠状动脉病变严重程度呈正相关(r＝0.331,P＜0.001)。ROC曲线分析显示,TyG指数的曲线下面积为0.680(95%CI:0.630～0.731,P＜0.001)。当TyG指数临界值取1.555时,其预测AMI患者发生严重冠状动脉病变风险的效能最高,灵敏度为79.4%,特异度为50.5%。 [结论]TyG作为一种新型生物标志物,与AMI患者冠状动脉病变的严重程度显著且独立相关。     

Body mass index,adipokines and insulin resistance in asthmatic children and adolescents

Objective: This study aimed to describe the body mass index, insulin resistance, levels of adipokines and inflammatory markers in Brazilian asthmatic children and adolescents and to investigate their possible association with the severity and control of asthma. Methods: Cross-sectional study (n?=?92; age: 3–18 years). Assessed data: Body weight and height, used to calculate the body mass index (BMIZ) and height-for-age (HAZ). Laboratory measurements: Lipid profile; glycemia and insulin for homeostasis model assessment (HOMA); adipokines; tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP) and monocyte chemoattractant protein-1 (MCP-1); total immunoglobulin E (IgE) and specific IgE against aeroallergens. Results: The median age was 9.6 years (3.0–16.6); most participants were male (n?=?52, 56.5%), pre-pubertal (n?=?54, 58.6%) and had atopic asthma (n?=?85, 92.4%). Overweight/obesity (38%) showed an inverse correlation with age (adjusted odds ratio [OR]?=?0.781; 95% confidence interval [CI] 0.66–0.92) and a direct correlation with the leptin concentration (adjusted OR?=?1.13; 95% CI 1.04–1.22). Insulin concentration was independently associated with moderated persistent asthma (adjusted OR?=?1.31; 95% CI 1.09–1.52). HOMA showed a direct correlation with the leptin (β?=?0.475; 95% CI 0.117–0.268) and total IgE (β?=?0.197; 95% CI 0.002–0.096) levels and an inverse correlation with the TNF-α levels (β?=??0.255; 95% CI;?0.366–0.055). Conclusions: Asthma was associated with insulin resistance and a systemic inflammatory response possibly mediated by adipokines, with leptin levels standing out among the participants with excess weight.     

HOMA2-IR是个较好的胰岛素抵抗指数

本文复习了HOMA2IR的由来及应用范围,认为在流行病学较大样本的研究中,它是一个较好的IR指数。     

Homeostasis model assessment of insulin resistance,quantitative insulin sensitivity check index,and oral glucose insulin sensitivity index in nonobese,nondiabetic subjects with high-normal blood pressure

To investigate the relationships between high-normal blood pressure (BP) and insulin resistance, we examined insulin sensitivity in 306 nonobese and nondiabetic Japanese subjects with various BP categories (optimal BP, normal BP, high-normal BP, and hypertension). Insulin sensitivity was measured from fasting plasma glucose and insulin values and those during a 75-g oral glucose tolerance test by five formulas: the homeostasis model assessment of insulin resistance (HOMA-R), the quantitative insulin sensitivity check index (QUICKI), the oral glucose insulin sensitivity (OGIS) index, and two insulin sensitivity indexes (ISI-composite and ISI-stumvoll). The HOMA-R was significantly higher, and the QUICKI was significantly lower in subjects with hypertension than in subjects with optimal BP. Both HOMA-R and QUICKI values showed that high-normal BP patients had a higher (but not significant) degree of insulin resistance than optimal BP patients. The OGIS index was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP. The ISI-composite was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP, and it was also significantly lower in subjects with hypertension than in subjects with normal BP. The ISI-stumvoll was significantly lower in subjects with high-normal BP or hypertension than in subjects with optimal BP. The OGIS index, ISI-composite, and ISI-stumvoll significantly decreased with increasing severity of BP status among the normotensive groups (optimal BP, normal BP, and high-normal BP). These findings indicate that insulin resistance is present even in the high-normal BP categories of nonobese and nondiabetic Japanese individuals.     

A novel index of insulin resistance determined from the homeostasis model assessment index and adiponectin levels in Japanese subjects

Insulin resistance is the principal cause of glucose intolerance and type 2 diabetes and induces progression of severe atherosclerosis in these patients. Adiponectin, the adipose-specific proteins, is known to correlate negatively with insulin resistance in patients with obesity and type 2 diabetes. The purpose of this study was to evaluate the potential of using serum adiponectin levels as a marker of insulin resistance in various states of insulin resistance. Furthermore, we attempted to establish a modified index of the homeostasis model assessment index (HOMA-IR), calculated from the product of serum insulin and plasma glucose levels divided by serum adiponectin levels (HOMA-AD). We recruited 117 Japanese subjects with various degrees of glucose tolerance and determined serum adiponectin levels and insulin sensitivity (M-value) by using the euglycemic hyperinsulinemic clamp technique. M-value, the gold standard index of insulin resistance, correlates significantly and independently with fasting insulin (r=-0.313, P<0.001), glucose (r=-0.319, P<0.001), and adiponectin (r=0.241, P<0.002) levels. M-values were more significantly correlated with HOMA-AD (r=-0.643, P<0.001) than HOMA-IR values (r=-0.591, P<0.001). In subjects with moderate hyperglycemia (fasting glucose levels>8.0mmol/L, n=30), HOMA-AD showed a more significant correlation with the M-value than HOMA-IR (r=-0.535, P=0.005 versus r=-0.461, P=0.010). We would therefore like to propose a novel index, HOMA-AD, as a simple and adequate index for determining insulin resistance even in diabetic patients with overt hyperglycemia.     

由血清甘油三酯和血糖所得简易指数用于评估胰岛素抵抗的临床研究

目的 在不同体重指数和糖耐量状态受试者中,比较由血甘油三酯和血糖所得简易胰岛素抵抗指数与两种传统方法稳态模型和静脉葡萄糖耐量试验(FSIGT)所得胰岛素抵抗指数(HOMA -IR和FSIGT-ISI)用于评估胰岛素抵抗的敏感性和特异性.方法 共收集1024名受试者.其中,正常对照组240名,单纯性肥胖组335例,糖调节受损组312例及初发2型糖尿病组137例,均进行口服75 g葡萄糖耐量试验及胰岛素释放试验,检测空腹血脂谱和其他重要生化指标.所有受试者中540名进行FSIGT.甘油三酯与空腹血糖所得简易指数为TyG,甘油三酯与餐后2h血糖所得简易指数为TyG2.结果 Pearson相关分析结果显示,TyG与HOMA-IR(r=0.427,P＜0.01)和FSIGT-ISI(r=-0.100,P=0.024)均显著相关.TyG2与HOMA-IR(r=0.455,P＜0.01)和FSIGT-ISI(r=-0.162,P＜0.01)亦显著相关.与HOMA-IR相比,TyG用于诊断胰岛素抵抗的敏感性和特异性分别为68.5％和63.5％,TyG2分别为81.7％和51.5％.与FSIGT-ISI相比,TyG用于诊断胰岛素抵抗的敏感性和特异性分别为68.5％和49.5％,TyG2分别为75.7％和48.2％.结论 在中国人群中,TyG和TyG2可以作为胰岛素抵抗的简易评价指数.但由于其存在敏感性高而特异性低的特点,限制了其在大规模流行病学筛查中的应用.     

Detection of insulin resistance by simple quantitative insulin sensitivity check index QUICKI for epidemiological assessment and prevention.

The aim of the present study was to evaluate the recently defined simple insulin sensitivity check index QUICKI (Katz et al. 2000) for insulin resistance diagnostics in common clinical and epidemiological practice. Both the QUICKI (1/log insulin + log glycemia in mg/dL) and HOMA (insulin * glycemia in micromol/L/22.5) indexes were calculated from fasting values in 259 adult healthy volunteers and patients, and in 47 healthy and obese children of prepubertal age of both sexes. In adults, a fall in the QUICKI index (mean +/- SEM in healthy subjects = 0.366 +/- 0.029) as well as an increase in the HOMA index (in healthy subjects 1.57 +/- 0.87) corresponded to metabolic and clinical manifestations of insulin resistance in various groups of outpatients. The QUICKI index had lower dispersion variances and the 95% confidence limits displayed a higher discrimination capacity. Patients with glucose intolerance or diabetes, hyperlipidemia typical for insulin resistance, or with combination of these metabolic disorders were characterized by QUICKI index values that were significantly lower than those of healthy volunteers. The QUICKI index in healthy prepubertal children indicated a higher insulin resistance compared to adults (mean 0.339 +/- 0.020); an increase in the QUICKI index in obese children with BMI over 25 was not significant, although obese children showed a significant increase of serum leptin and triglycerides and a decrease of HDL-cholesterol. Adult patients with QUICKI index below 0.357 (which is at the lower limit of 95% confidence limits in healthy persons) represented a group with typical manifestations of metabolic syndrome, differing in these parameters significantly from the group of patients of comparable age with a QUICKI index greater than 0.357. The present study suggests suitability of the QUICKI index for diagnosis of insulin resistance in clinical and epidemiological practice. However, a normal QUICKI index range needs to be established for each laboratory with an appropriate control group because of significant interlaboratory variations in insulin determinations and/or possible differences in various populations.     

Triglycerides and glucose index as an insulin resistance marker in a sample of healthy adults

AimTo assess the association between elevated triglycerides/glucose index (TGI) and insulin resistance (IR) or hyperinsulinemia after oral glucose tolerance test (OGTT) in a sample of healthy adults.MethodsWe conducted an analytical cross-sectional study in euthyroid non-diabetic adults, who attended the outpatient service of a private clinic in Lima-Peru during the 2012–2016 period. Participants were categorized in two groups according to the presence or absence of elevated TGI, IR or hyperinsulinemia after OGTT. A TGI value ≥ 8.65 was considered as elevated. We defined IR as a Homeostasis Model Assessment (HOMA-IR) value ≥ 2.28 and hyperinsulinemia after OGTT as a serum insulin value ≥ 80μU/mL after 120 min of 75-g glucose intake. We elaborated crude and adjusted Poisson regression models to assess the association between elevated TGI and IR or hyperinsulinemia after OGTT. The reported association measure was the prevalence ratio (PR) with their respective 95% confidence intervals (95%CI).ResultsWe analyzed 118 individuals, the average age was 37.5 ± 11.3 years, 21 (17.8%) were males and the median BMI was 22.7 ± 1.6 kg/m². The prevalence of elevated TGI was 25.4% (n=30) while the prevalence of IR and hyperinsulinemia after OGTT was 24.6% (n=29) and 17.0% (n=20) respectively. In the adjusted model, elevated TGI was associated with both IR (aPR=6.36; 95%CI: 3.41–11.86) and hyperinsulinemia after OGTT (aPR=4.19; 95%CI: 1.81–9.70).ConclusionsWe found that elevated TGI was associated with both IR markers in a sample of euthyroid adults without T2DM and with a normal BMI. The simplicity of the TGI calculation makes it the first-choice alternative when the hyperinsulinemic-euglycemic clamp or HOMA-IR are not available.     

TyG index, HOMA score and viral load in patients with chronic hepatitis C due to genotype 1

Summary. The triglycerides × glucose (TyG) index is a recently proposed surrogate marker of insulin resistance (IR), calculated from fasting plasma triglyceride and glucose concentrations. We tested the host and viral factors associated with Tyg and homeostasis model assessment (HOMA) scores, comparing their associations with histological features and with sustained virological response (SVR) in patients with genotype 1 chronic hepatitis C(G1CHC). Three hundred and forty consecutive patients with G1CHC were considered. All had a liver biopsy scored by one pathologist for staging and grading (Scheuer), and graded for steatosis, which was considered moderate–severe if ≥30%. Anthropometric and metabolic measurements, including IR measured by both HOMA and TyG, were registered. By linear regression analysis, TyG was independently associated with waist circumference (WC), total cholesterol, presence of arterial hypertension, Log10 HCV‐RNA and steatosis. Similarly, WC and steatosis were significantly associated with HOMA. Older age (OR, 1.036; 95%CI, 1.004–1.070, P = 0.02), higher WC (1.031; 1.004–1.060; P = 0.02) and higher TyG (11.496; 3.163–41.784; P < 0.001) were linked to moderate‐to‐severe steatosis (≥30%) by multiple logistic regression analysis. When TyG was replaced by HOMA‐IR in the model, the latter remained significantly associated with steatosis ≥30% (1.237; 1.058–1.448; P = 0.008). Receiver operating characteristic curves showed a similar performance of TyG (AUC 0.682) and HOMA‐IR (AUC 0.699) in predicting moderate–severe steatosis. No independent associations were found between both TyG and HOMA and fibrosis or SVR. In patients with G1CHC , TyG, an easy‐to‐calculate and low‐cost surrogate marker of IR, is linked to liver steatosis and shows an independent association with viral load.     

TyG index performs better than HOMA in a Brazilian population: a hyperglycemic clamp validated study

The TyG index was evaluated as a surrogate method for estimation of insulin resistance (IR). TyG index correlated with adiposity, metabolic and atherosclerosis markers related to IR and presented a moderate degree of agreement with hyperglycemic clamp. TyG index represents an accessible tool for assessment of IR in clinical practice.