Fasting indices of glucose-insulin-metabolism across life span and prediction of glycemic deterioration in children with obesity from new diagnostic cut-offs.

Background: Fasting indices of glucose-insulin-metabolism are an easy and affordable tool to assess insulin resistance. We aimed to establish reference ranges for fasting insulin indices that reflect age-dependent variation over the entire life span and subsequently test their clinical application regarding the prediction of glycemic deterioration in children. Methods: We calculated age- and puberty-dependent reference values for HOMA-IR, HOMA2-IR, HOMA-ß, McAuley index, fasting insulin, and fasting glucose from 6994 observations of 5512 non-obese healthy subjects aged 5-80 years. Applying those references, we determined the prevalence of insulin resistance among 2538 subjects with obesity. Furthermore, we investigated the intraindividual stability and the predictive values for future dysglycemia of these fasting indices in 516 children and adolescents with obesity up to 19 years of follow-up. We validated the results in three independent cohorts. Findings: There was a strong age-dependent variation of all indices throughout the life span, including prolonged recovery of pubertal insulin resistance and a subsequent continuous increase throughout adulthood. Already from age 5 years onwards, >40% of children with obesity presented with elevated parameters of insulin resistance. Applying newly developed reference ranges, insulin resistance among children with obesity doubled the risk for future glycemic deterioration (HOMA-IR HR 1.88 (95% CI 1.1-3.21)), fasting insulin HR 1.89 (95% CI 1.11-3.23). In contrast, fasting glucose alone was not predictive for emerging dysglycemia in children with obesity (HR 1.03 (95% CI 0.62-1.71)). The new insulin-based thresholds were superior to fasting glucose and HbA1c in detecting children eventually manifesting with dysglycemia in prospective analyses. Interpretation: The variation of fasting glucose-insulin-metabolism across the life span necessitates age-specific reference ranges. The improved prediction of future glycemic deterioration by indices based on fasting insulin beyond simple glucose measures alone could help to stratify risk characteristics of children with obesity in order to guide patient-tailored prevention and intervention approaches. Funding: German Research Foundation (DFG)-through SFB 1052, project number 209933838, subproject C5; Federal Ministry of Education and Research, Germany; European Union-European Regional Development Fund; Free State of Saxony. The German Diabetes Association, the CarbHealth consortium (01EA1908B). EU-IMI2-Consortium SOPHIA (grant agreement No 875534), German Center for Diabetes Research (DZD), grant number 82DZD14E03.

Insulin Resistance in Gestational Diabetes Mellitus and Its Association With Anthropometric Fetal Indices.

Background: In pregnant women with gestational diabetes mellitus (GDM), insulin resistance (IR) increases the risk of developing manifest type 2 diabetes mellitus and is associated with complications in both mother and fetus. Objectives: This research aimed to evaluate the associations between IR evaluated by 3 indices (namely updated homeostasis model assessment model (HOMA2), QUICKI, and McAuley's index) and the diabetes risk factors and the fetal growth indices in Vietnamese women with GDM. Methods: A cross-sectional descriptive study was conducted on 370 women with GDM and 40 healthy pregnant women from January 2015 to May 2019. IR was calculated by HOMA2 (HOMA2-IR), QUICKI, and McAuley's index. Fetal anthropometric measurements were assessed via ultrasound which was performed and interpreted by ultrasound experts. Results: In the simple regression analysis, McAuley's index illustrated had statistically significant correlations to the highest number of risk factors of diabetes mellitus compared with HOMA2-IR and QUICKI indices. Moreover, McAuley's index correlated statistically significantly to the highest number of fetal ultrasound measurements factors such as including biparietal diameter (BPD) (r = -0.271, P < .001), head circumference (HC) (r = -0.225, P < .001), abdominal circumference (AC) (r = -0.214, P < .001), femur length (FL) (r = -0.231, P < .001), estimated fetal weight (EFW) (r = -0.239, P < .001) and fetal estimated age (r = -0.299, P < .001). In the multivariable analysis, the McAuley's index contributed the greatest to AC (Standardized B of -0.656, P < .001). Conclusion: The McAuley's index was significantly associated with a higher number of more risk factors for diabetes mellitus as well as fetal ultrasound sonography findings measurements than compared with HOMA2-IR and QUICKI indices.

Comparación de los índices triglicéridosglucosa y McAuley en el síndrome metabólico en personas con riesgo para diabetes tipo 2 / Comparison of the triglyceride-glucose and McAuley indices in metabolic syndrome in people at risk for type 2 diabetes

Resumen La prevalencia de la glucosa elevada en ayunas y la diabetes tipo 2 (DT2) está aumentando en la Argentina. Interesa encontrar índices de insulinorresistencia accesibles al laboratorio clínico con bajo costo. En 74 varones y 142 mujeres con riesgo para DT2 se analizaron los índices de McAuley y triglicéridos-glucosa (T-G) para: a) determinar los valores del índice de McAuley y su correlación con el índice T-G; b) comparar ambos índices para la detección del síndrome metabólico (SM) y su concordancia; c) determinar la asociación con los componentes de SM. Para McAuley la mediana fue 6,68 y el rango intercuartílico (5,47-8,25) y para T-G fue 8,71 (8,35-9,05) respectivamente. La correlación entre ambos fue r=-0,802, p<0,001. Respecto del SM, las áreas bajo la curva ROC fueron: índice T-G=0,816±0,029 (IC95% 0,758-0,873), p<0,001 y para el 1/índice de McAuley=0,816±0,030 (IC95% 0,758-0,874) p<0,001. La concordancia Kappa entre ambos fue 0,630, p<0,001, Chi cuadrado 85,74 (p<0,001). Para T-G y McAuley la sensibilidad fue 80,7% y 80,7%, la especificidad 70,7% y 69,4%, PP+ 62,5% y 62%, PP- 83,9 y 85,3%, la razón de probabilidad positiva (RP+) fue 2,65 y 2,64 y la negativa (RP-) fue 0,30 y 0,27 respectivamente. Ambos se asociaron con triglicéridos ≥150 mg/dL y glucosa ≥100 mg/dL y ninguno con C-HDL bajo y presión arterial ≥130/85 mmHg o en tratamiento. McAuley mostró asociación con cintura ≥102/88 cm (p>0,001). Se concluye que T-G mostró una aceptable concordancia con McAuley y ambos una similar asociación con SM. T-G podría ser útil para estudios en poblaciones pero para su aplicación en la clínica se necesitan más estudios.

Abstract The prevalence of high fasting glucose and type 2 diabetes (T2D) is increasing in our country. It is interesting to find insulin resistance indices accessible to the clinical laboratory at low cost. In 74 men and 142 women at risk for T2D, the McAuley and triglyceride-glucose (T-G) indices were analised to: a) determine the McAuley index values and they correlation with the T-G index; b) compare both indices for the detection of metabolic syndrome (MS) and their concordance; c) determine the association with MS components. For McAuley the median was 6.68 and the interquartile range (5.47-8.25) and for T-G it was 8.71 (8.35-9.05) respectively. The correlation between both was r=-0.802, p<0.001. Regarding MS, the areas under the ROC curve were: TG index=0.816±0.029 (95%CI 0.758-0.873), p<0.001 and for the 1/McAuley index=0.816±0.030 (95%CI 0.758-0.874) p<0.001. The Kappa agreement between the two indices was 0.630, p<0.001, Chi square 85.74 (p<0.001). For TG and McAuley the sensitivities were 80.7% and 80.7%, the specificities 70.7% and 69.4%, PP+ 62.5% and 62%, PP- 83.9 and 85.3%, the ratios of positive probability (PR+) were 2.65 and 2.64 and negative probability (PR-) were 0.30 and 0.27 respectively. Both were associated with triglycerides≥150 mg/dL and glucose≥100 mg/dL and neither with low HDL-C and blood pressure≥130/85 mmHg or treated. McAuley showed an association with waist≥102/88 cm (p>0.001). It is concluded that T-G showed acceptable agreement with McAuley and both similar association with SM. T-G could be useful for population studies but further studies are needed for its clinical application.

Resumo A prevalência de glicose elevada em jejum e a diabetes tipo 2 (DM2) está aumentando na Argentina. Interessanos achar índices de resistência à insulina acessíveis ao laboratório clínico a baixo custo. Em 74 homens e 142 mulheres em risco de DT2, os índices de McAuley e triglicerídeos-glicose (T-G) foram analisados para: a) determinar os valores do índice de McAuley e sua correlação com o índice T-G; b) comparar os dois índices para detecção da síndrome metabólica (SM) e sua concordância; c) determinar a associação com componentes SM. Para McAuley a mediana foi de 6,68 e o intervalo interquartil (5,47-8,25) e para T-G foi de 8,71 (8,35-9,05), respectivamente. A correlação entre os dois foi r=-0,802, p<0,001. Em relação à SM, as áreas sob a curva ROC foram: índice T-G=0,816±0,029 (IC95% 0,758-0,873), p<0,001 e para o 1/índice de McAuley=0,816±0,030 (IC95% 0,758-0,874) p<0,001. A concordância Kappa entre os dois foi de 0,630, p<0,001, Qui quadrado 85,74 (p<0,001). Para T-G e McAuley a sensibilidade foi 80,7% e 80,7%, especificidade 70,7% e 69,4%, PP+ 62,5% e 62%, PP- 83,9 e 85,3%, a razão de probabilidade positiva (RP+) foi 2,65 e 2,64 e negativa (RP-) foi de 0,30 e 0,27, respectivamente. Os dois foram associados com triglicerídeos≥150 mg/dL e glicose≥100 mg/dL e nenhum com C-HDL baixo e pressão arterial≥130/85 mmHg ou tratamento. McAuley mostrou associação com cintura≥102/88 cm (p>0,001). Conclui-se que T-G apresentou concordância aceitável com McAuley e ambos os dois associação semelhante a SM. T-G poderia ser útil para estudos populacionais, mas mais estudos são necessários para sua aplicação clínica.

Correlation of Surrogate Markers of Insulin Resistance with Fasting Insulin in Type 2 Diabetes Mellitus Patients: A Study of Malwa Population in Punjab, India.

Context Insulin resistance (IR) and abnormal insulin secretion play a key role for the development of type 2 diabetes mellitus (DM). Aims We investigated the surrogate markers of IR, i.e., Homeostasis Model Assessment (HOMA), Quantitative Insulin Sensitivity Check Index (QUICKI), McAuley, and Fasting Insulin Resistance Index (FIRI) in type 2 DM patients. Also, fasting insulin (FI) levels were estimated in type 2 diabetics. Further, the correlation of FI with other surrogate markers of IR in type 2 DM was done. Settings and Design A hundred newly diagnosed patients with type 2 DM from Malwa population, Punjab, were considered for evaluation. Another 100 healthy individuals (age and sex-matched) were examined as controls. Methods and Material Fasting blood glucose, FI, and lipid profile were estimated, and IR was calculated using McAuley index (McA), HOMA, QUICKI, and FIRI. Statistical Analysis Used The statistical analysis was performed on the above-mentioned clinical interpretations. The Cohen's kappa test was used to affirm the agreement. Results FI levels in patients with type 2 diabetes were significantly higher (20.8 ± 9.05 µIU/L) than controls (7.93 ± 1.01 µIU/L). IR by surrogate markers was found significant in the study group. The 76% patients with type 2 diabetes ended up as resistant to insulin by FI measurement, almost equivalent to McA, 80%; HOMA, 88%; FIRI, 88%; and QUICKI, 90%. A notable correlation was highlighted between FI and McA manifesting IR ( p < 0.01, r = -0.85). We calculated the statistical correlation of FI with HOMA, QUICKI, and FIRI indices ( p < 0.01, r = 0.93; p < 0.01 r = -0.92; and p < 0.01, r = +0.93, respectively). The agreement visible from Cohen's kappa test also affirms the same ( k = 0.9 for McA). Conclusion We concluded that all the surrogate markers for IR were specific when compared with FI, but in terms of sensitivity McA was found to be more sensitive as it includes markers of dyslipidemia, which is the precipitating factor of metabolic derangements so as the IR in type 2 DM.

Cut-off Values and Clinical Utility of Surrogate Markers for Insulin Resistance and Beta-Cell Function to Identify Metabolic Syndrome and Its Components among Southern Indian Adults.

BACKGROUND: Insulin resistance (IR) is a collective clinical entity that exacerbates metabolic syndrome (MetS). As the gold-standard test to quantify IR involves intravenous insulin loading and repeated blood glucose monitoring, many indices have been developed for IR assessment for convenience. This study tested the ideal cut-off values and clinical utility of IR indices in identifying MetS. METHODS: We recruited 150 subjects, 75 MetS patients and 75 healthy controls, then obtained written informed consent to participate in this study. We collected fasting blood samples for glucose and lipid profiles and calculated nineteen indices of IR and insulin secretion using validated formulae. We determined the precision of these IR indices using the area under the curve (AUC) in a receiver operating characteristic analysis. RESULTS: Subjects with MetS have significantly higher IR coupled with lower insulin sensitivity and beta-cell function than controls. Among the surrogate markers of IR tested, the homeostatic model assessment of insulin resistance (HOMA-IR), HOMA-adiponectin (HOMA-AD), triglyceride-glucose (TyG) index, HOMA-1%S (insulin sensitivity), quantitative insulin sensitivity check index (QUICKI), McAuley index, single-point insulin sensitivity estimator (SPISE), and HOMA-2%B (beta-cell function) showed the highest AUC values for detecting MetS. CONCLUSION: Our study results suggest that the ideal cut-off and AUC values identified for HOMA-IR, HOMA-AD, the TyG index, HOMA-1%S, QUICKI, the McAuley index, SPISE, and HOMA-2%B offer a clinical approach to the early detection and risk stratification for MetS among people in southern India.

Prevalence of Insulin Resistance in the Hungarian General and Roma Populations as Defined by Using Data Generated in a Complex Health (Interview and Examination) Survey.

Data mainly from one-off surveys clearly show that the health of Roma, the largest ethnic minority of Europe, is much worse than that of the general population. However, results from comprehensive exploratory studies are missing. The aim of our study was to create a complex database for comparative and association studies to better understand the background of the very unfavourable health of Roma, especially the high burden of cardiometabolic diseases. A three-pillar (questionnaire-based, physical and laboratory examinations) health survey was carried out on randomly selected samples of the Hungarian general (HG, n = 417) and Roma (HR, n = 415) populations, and a database consisting of more than half a million datapoints was created. Using selected data, the prevalence rates of metabolic syndrome (MetS) and of its components were determined, and to estimate the risk of insulin resistance (IR), surrogate measures (the homeostasis model assessment of insulin resistance index, quantitative insulin sensitivity check index, McAuley and TyG indices and the TG/HDL-C ratio) were calculated. Receiver operating characteristic curve analysis and Youden's method were used to define the optimal cut-off values of each IR index. The prevalence of MetS was very high in both study populations (HG: 39.8%, HR: 44.0%) with no statistically significant difference between the two groups in females or males. The prevalence of MetS showed a very marked increase in the HR 35-49 years age group. Among surrogate measures, the TyG index showed the greatest power for predicting IR/MetS at a cut-off value of 4.69 (77% sensitivity, 84% specificity) and indicated a 42.3% (HG) and 40.5% (HR) prevalence of IR. The prevalence of MetS and IR is almost equally very unfavourable in both groups; thus, the factors underlying the high premature mortality burden of Roma should be further clarified by investigating the full spectrum of risk factors available in the database, with a special focus on the access of Roma people to preventive and curative health services.

Influence of LRP5 (rs556442) polymorphism on insulin resistance in healthy Iranian children and adolescents

Background/aim: Genetic aspects play a role in insulin resistance in children. In this study, for the first time, the association of LRP5 (rs556442) polymorphism and insulin resistance in Iranian children and adolescents was investigated. Materials and methods: The study population comprises children and adolescents aged 9­18 years. Anthropometric and biochemical parameters were assessed. Insulin resistance/sensitivity was determined by the quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment-insulin resistance (HOMA-IR), insulin-to-glucose ratio, McAuley index, revised McAuley index, fasting insulin resistance index (FIRI), and Bennett's index. LRP5 (rs566442) single nucleotide polymorphism (SNP) was identified using restriction fragment length polymorphism (RFLP). Linear regression analysis was used to determine the association between the LRP5 polymorphism (rs556442) and insulin sensitivity indexes. Results: Significant differences were found between GG genotype vs. AG/AA genotypes for McAuley index (P = 0.049) and revised McAuley index (P = 0.044) when adjusted for interaction factors (age, sex, and puberty) in regression models. No significant association was found between LRP5 (rs566442) and other insulin resistance indexes. Also, LRP5 (rs566442) did not show a significant impact on biochemical parameters. Conclusion: This study showed that LRP5 polymorphism (rs556442) was associated with insulin resistance in Iranian children and adolescents.

The Cut-off Values of Surrogate Measures for Insulin Sensitivity in a Healthy Population in Korea according to the Korean National Health and Nutrition Examination Survey (KNHANES) 2007-2010.

BACKGROUND: This study aimed to identify the gender-specific characteristics of the surrogate measures of insulin resistance and to establish valid cut-off values for metabolic abnormalities in a representative sample in Korea. METHODS: Data were collected from the datasets of the Korean National Health and Nutrition Examination Survey between 2007 and 2010. The total number of eligible participants was 10,997. We used three measures of insulin resistance: the homeostasis model assessment-insulin resistance (HOMA-IR), McAuley index, and triglyceride and glucose (TyG) index. The estimated cut-off values were determined using the highest score of the Youden index. RESULTS: The area under the curve (AUC) of the HOMA-IR, McAuley index, and TyG index were 0.737 (95% confidence interval [CI], 0.725-0.750), 0.861 (95% CI, 0.853-0.870), and 0.877 (95% CI, 0.868-0.885), respectively. The cut-off values of the HOMA-IR were 2.20 in men, 2.55 in premenopausal women, and 2.03 in postmenopausal women, and those of the McAuley index were 6.4 in men and 6.6 in premenopausal and postmenopausal women. For the TyG index, the cut-off values were 4.76 in men and 4.71 in premenopausal and postmenopausal women. CONCLUSION: In conclusion, the present study provides the valid cut-off values of the indirect surrogate measures of insulin sensitivity. These values may be used as reference for insulin sensitivity in a clinical setting and may provide a simple and supplementary method for identifying populations at risk of insulin resistance.

Limitations of insulin resistance assessment in polycystic ovary syndrome.

BACKGROUND: Though insulin resistance (IR) is common in polycystic ovary syndrome (PCOS), there is no agreement as to what surrogate method of assessment of IR is most reliable. SUBJECTS AND METHODS: In 478 women with PCOS, we compared methods based on fasting insulin and either fasting glucose (HOMA-IR and QUICKI) or triglycerides (McAuley Index) with IR indices derived from glucose and insulin during OGTT (Belfiore, Matsuda and Stumvoll indices). RESULTS: There was a strong correlation between IR indices derived from fasting values HOMA-IR/QUICKI, r = -0.999, HOMA-IR/McAuley index, r = -0.849 and between all OGTT-derived IR indices (e.g. r = -0.876, for IRI/Matsuda, r = -0.808, for IRI/Stumvoll, and r = 0.947, for Matsuda/Stumvoll index, P < 0.001 for all), contrasting with a significant (P < 0.001), but highly variable correlation between IR indices derived from fasting vs OGTT-derived variables, ranging from r = -0.881 (HOMA-IR/Matsuda), through r = 0.58, or r = -0.58 (IRI/HOMA-IR, IRI/QUICKI, respectively) to r = 0.41 (QUICKI/Stumvoll), and r = 0.386 for QUICKI/Matsuda indices. Detailed comparison between HOMA-IR and IRI revealed that concordance between HOMA and IRI was poor for HOMA-IR/IRI values above 75th and 90th percentile. For instance, only 53% (70/132) women with HOMA-IR >75th percentile had IRI value also above 75th percentile. There was a significant, but weak correlation of all IR indices with testosterone concentrations. CONCLUSIONS: Significant number of women with PCOS can be classified as being either insulin sensitive or insulin resistant depending on the method applied, as correlation between various IR indices is highly variable. Clinical application of surrogate indices for assessment of IR in PCOS must be therefore viewed with an extreme caution.

Relationship between several surrogate estimates of insulin resistance and a direct measure of insulin-mediated glucose disposal: Comparison of fasting versus post-glucose load measurements.

AIMS: The study aim was to determine the correlation of several surrogate estimates of insulin resistance with a direct measure of insulin action and the ability of these estimates to identify insulin resistant persons. METHODS: Retrospective analysis of 454 apparently healthy individuals studied in a clinical research center. The correlations between 11 surrogate estimates of insulin resistance, using either fasting or post-oral glucose challenge values, and a direct measure of insulin-mediated glucose uptake (SSPG concentration during the Insulin Suppression Test) were determined as well as the ability of the surrogate estimates to identify insulin resistant individuals. RESULTS: All surrogate estimates were significantly (P < .001) correlated with SSPG concentrations and successfully identified insulin resistant persons. These relationships were of lesser magnitude when estimates were based on fasting data, with the exception of the McAuley index-derived from fasting data, but resembling post-glucose challenge estimates. Moreover, correlation with SSPG concentration, and positive identification of insulin resistance, varied considerably among estimates. CONCLUSION: All 11 surrogate estimates of insulin resistance significantly correlated with insulin-mediated glucose disposal and identified insulin resistant persons with a reasonable degree of sensitivity and specificity. For identification of insulin resistant individuals, indices based on post-glucose challenge measurements performed better than those based on fasting measurements, with the exception of McAuley index. The quantitative information derived from this analysis should help investigators select the surrogate marker of insulin resistance best suited for their study.

Acute changes in blood lipid profiles and metabolic risk factors in collegiate elite taekwondo athletes after short-term de-training: a prospective insight for athletic health management.

BACKGROUND: This study used a short-term de-training model to mimic the physiological weight changes during the early retirement stage in Taekwondo (TKD) athletes. This study investigates whether the negative changes in body composition, blood lipid profiles, and metabolic biomarkers occur in elite collegiate TKD athletes when experiencing a two-months de-training period. METHODS: Fourteen collegiate Division Ι elite TKD athletes (age: 21.1 ± 0.2 years, BMI: 22.3 ± 1.1 kg/m2; 10 males and 4 females) participated in this study. The body composition, blood lipid profiles, atherogenic dyslipidemia indexes, metabolic biomarkers and baseline systemic inflammation states were measured before and after two-months de-training. RESULTS: The body weight and BMI did not change after de-training in these elite TKD athletes. The total muscle mass displayed a significant decline after de-training (-2.0%, p = 0.019), with an increase in fat mass (+24.3%, p < 0.01). The blood triglyceride did not change, but the total cholesterol was higher after de-training (+8.3%, p = 0.047). The CHOL-to-HDL and LDL-to-HDL ratios increased by 12.4% (p < 0.001) and 13.2% (p = 0.002) after de-training, respectively. The blood platelet number, plateletcrit, and platelet-to-lymphocyte ratio increased significantly by 5.0% (p = 0.013), 7.3% (p = 0.009), and 20.6% (p = 0.018) after de-training, respectively. The McAuley's Index decreased (-6.9%, p = 0.025) after de-training. CONCLUSION: We demonstrated that a two-months de-training period resulted in adverse effects on early atherogenic dyslipidemia development, progressing insulin resistance, low-grade inflammation, and visceral adiposity in young elite TKD athletes. Our findings provide clear insights into the possible deleterious impacts at early stage retirement in former combative sports athletes.

Comparison of Surrogate Markers as Measures of Uncomplicated Insulin Resistance in Korean Adults.

BACKGROUND: Metabolic syndrome (MS) is known to increase the risk of various cardiometabolic diseases and in-sulin resistance (IR) has known to have central role in the development of MS. Many surrogate indices of IR have been proposed and the detection of MS might be a suitable model for assessing the accuracy of surrogate indices. The aims of our study are to invest the most appropriate index by assessment of the diagnostic capacity of IR among each surrogate index and identifying cut-off values for discriminating uncomplicated MS in Korean adults. METHODS: A cross-sectional study was performed, assessing 294 Korean adults, 85 of whom were diagnosed with uncomplicated MS. The sensitivities and specificities of five surrogate IR indices were compared to discriminate MS from healthy subjects; these included fasting serum insulin, homeostasis model assessment-insulin resistance index, quantitative insulin sensitivity check index, McAuley index, and Disse index. Correlations between each index value were assessed using Pearson's and Spearman's correlation methods. RESULTS: The McAuley index showed the highest area under the curve (0.85), specificity (86.12%), accuracy (82.31%), positive predictive value (68.13%), and negative predictive value (88.67%) to distinguish MS, with a cut-off point of 5.3 defined. Correlation coefficients of the five indices showed that the McAuley index had the strongest correlation with IR. CONCLUSION: The McAuley index showed the best accuracy in the detection of MS as a surrogate marker of IR. To establish more effective and accurate standards of measuring IR, comprehensive and multi-scaled studies are required.

Lower serum magnesium concentration is associated with diabetes, insulin resistance, and obesity in South Asian and white Canadian women but not men.

BACKGROUND: A large proportion of adults in North America are not meeting recommended intakes for magnesium (Mg). Women and people of South Asian race may be at higher risk for Mg deficiency because of lower Mg intakes relative to requirements and increased susceptibility to diabetes, respectively. OBJECTIVE: This study compared serum Mg concentrations in South Asian (n=276) and white (n=315) Canadian women and men aged 20-79 years living in Canada's Capital Region and examined the relationship with diabetes, glucose control, insulin resistance, and body mass index. RESULTS: Serum Mg concentration was lower in women of both races and South Asians of both genders. Racial differences in serum Mg were not significant after controlling for use of diabetes medication. A substantial proportion of South Asian (18%) and white (9%) women had serum Mg <0.75 mmol/L indicating hypomagnesemia. Use of diabetes medication and indicators of poorer glucose control, insulin resistance, and obesity were associated with lower serum Mg in women, but not in men. CONCLUSIONS: These results suggest that the higher incidence of diabetes in South Asians increases their risk for Mg deficiency and that health conditions that increase Mg requirements have a greater effect on Mg status in women than men.

Comparison of McAuley/fasting insulin indices with ATP III clinical criteria for the diagnosis of insulin resistance in type 2 diabetes mellitus.

OBJECTIVE: To estimate the prevalence of insulin resistant syndrome (IRS) among newly diagnosed patients with type 2 diabetes and to test their validity against two indices of insulin resistance (IR). MATERIALS AND METHODS: Prevalence of IRS was estimated according to the criteria used by ATP III in newly diagnosed type 2 diabetic patients. Sensitivity and specificity of the ACE criteria were calculated against two indices of IR namely fasting insulin (FI) level > 12 mU/l and McAuley index (McA) < 5.8. [McA= exp [2.63--0.28 ln(insulin in mU/l) -- 0.31 ln(triglycerides in mmol/l)]. RESULTS: 35.7% of patients had IRS by ATP III criteria. 64.3% of patients were insulin resistant by FI and McA in each index. In patients who had IRS with ATP criteria, 80% and 86.6% were found to have McA and FI in the insulin resistant range. Out of the patients who were resistant by McA, only 40.6% had IR by ACE criteria and 93% had shown IR by FI. Out of all patients who did not fulfill the ATP III for IR, 74% and 59% were detected as having IR by fasting insulin and McA respectively. Sensitivity of the ACE criteria when tested against the FI and McA were 37.5% and 40.6%, specificity were 70% and 80%, respectively. CONCLUSIONS: IRS was common among the newly diagnosed patients with type 2 diabetes. ACE criteria showed an acceptable specificity but lack adequate sensitivity when compared with the two Indices of insulin resistance. More valid and clinically useful criteria should be available for the accurate diagnosis of IRS in clinical practice.