Metabolomic profiling of the Dietary Approaches to Stop Hypertension diet provides novel insights for the nutritional epidemiology of type 2 diabetes mellitus.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is inversely associated with type 2 diabetes mellitus (T2DM) risk. Metabolic changes due to DASH adherence and their potential relationship with incident T2DM have not been described. The objective is to determine metabolite clusters associated with adherence to a DASH-like diet in the Insulin Resistance Atherosclerosis Study cohort and explore if the clusters predicted 5-year incidence of T2DM. The current study included 570 non-diabetic multi-ethnic participants aged 40­69 years. Adherence to a DASH-like diet was determined a priori through an eighty-point scale for absolute intakes of the eight DASH food groups. Quantitative measurements of eighty-seven metabolites (acylcarnitines, amino acids, bile acids, sterols and fatty acids) were obtained at baseline. Metabolite clusters related to DASH adherence were determined through partial least squares (PLS) analysis using R. Multivariable-adjusted logistic regression was used to explore the associations between metabolite clusters and incident T2DM. A group of acylcarnitines and fatty acids loaded strongly on the two components retained under PLS. Among strongly loading metabolites, a select group of acylcarnitines had over 50 % of their individual variance explained by the PLS model. Component 2 was inversely associated with incident T2DM (OR: 0·89; (95 % CI 0·80, 0·99), P-value = 0·043) after adjustment for demographic and metabolic covariates. Component 1 was not associated with T2DM risk (OR: 1·02; (95 % CI 0·88, 1·19), P-value = 0·74). Adherence to a DASH-type diet may contribute to reduced T2DM risk in part through modulations in acylcarnitine and fatty acid physiology.

NT-proBNP by Itself Predicts Death and Cardiovascular Events in High-Risk Patients With Type 2 Diabetes Mellitus.

Background NT-proBNP (N-terminal pro-B-type natriuretic peptide) improves the discriminatory ability of risk-prediction models in type 2 diabetes mellitus (T2DM) but is not yet used in clinical practice. We assessed the discriminatory strength of NT-proBNP by itself for death and cardiovascular events in high-risk patients with T2DM. Methods and Results Cox proportional hazards were used to create a base model formed by 20 variables. The discriminatory ability of the base model was compared with that of NT-proBNP alone and with NT-proBNP added, using C-statistics. We studied 5509 patients (with complete data) of 8561 patients with T2DM and cardiovascular and/or chronic kidney disease who were enrolled in the ALTITUDE (Aliskiren in Type 2 Diabetes Using Cardiorenal Endpoints) trial. During a median 2.6-year follow-up period, 469 patients died and 768 had a cardiovascular composite outcome (cardiovascular death, resuscitated cardiac arrest, nonfatal myocardial infarction, stroke, or heart failure hospitalization). NT-proBNP alone was as discriminatory as the base model for predicting death (C-statistic, 0.745 versus 0.744, P=0.95) and the cardiovascular composite outcome (C-statistic, 0.723 versus 0.731, P=0.37). When NT-proBNP was added, it increased the predictive ability of the base model for death (C-statistic, 0.779 versus 0.744, P<0.001) and for cardiovascular composite outcome (C-statistic, 0.763 versus 0.731, P<0.001). Conclusions In high-risk patients with T2DM, NT-proBNP by itself demonstrated discriminatory ability similar to a multivariable model in predicting both death and cardiovascular events and should be considered for risk stratification. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00549757.

Three-question set from Michigan Neuropathy Screening Instrument adds independent prognostic information on cardiovascular outcomes: analysis of ALTITUDE trial.

AIMS/HYPOTHESIS: The self-administered Michigan Neuropathy Screening Instrument (MNSI) is used to diagnose diabetic peripheral neuropathy. We examined whether the MNSI might also provide information on risk of death and cardiovascular outcomes. METHODS: In this post hoc analysis of the Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE) trial, we divided 8463 participants with type 2 diabetes and chronic kidney disease (CKD) and/or cardiovascular disease (CVD) into independent training (n = 3252) and validation (n = 5211) sets. In the training set, we identified specific questions that were independently associated with a cardiovascular composite outcome (cardiovascular death, resuscitated cardiac arrest, non-fatal myocardial infarction/stroke, heart failure hospitalisation). We then evaluated the performance of these questions in the validation set. RESULTS: In the training set, three questions ('Are your legs numb?', 'Have you ever had an open sore on your foot?' and 'Do your legs hurt when you walk?') were significantly associated with the cardiovascular composite outcome. In the validation set, after multivariable adjustment for key covariates, one or more positive responses (n = 3079, 59.1%) was associated with a higher risk of the cardiovascular composite outcome (HR 1.54 [95% CI 1.28, 1.85], p < 0.001), heart failure hospitalisation (HR 1.74 [95% CI 1.29, 2.35], p < 0.001), myocardial infarction (HR 1.81 [95% CI 1.23, 2.69], p = 0.003), stroke (HR 1.75 [95% CI 1.20, 2.56], p = 0.003) and three-point major adverse cardiovascular events (MACE) (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke) (HR 1.49 [95% CI 1.20, 1.85], p < 0.001) relative to no positive responses to all questions. Associations were stronger if participants answered positively to all three questions (n = 552, 11%). The addition of the total number of affirmative responses to existing models significantly improved Harrell's C statistic for the cardiovascular composite outcome (0.70 vs 0.71, p = 0.010), continuous net reclassification improvement (+22% [+10%, +31%], p = 0.027) and integrated discrimination improvement (+0.9% [+0.4%, +2.1%], p = 0.007). CONCLUSIONS/INTERPRETATION: We identified three questions from the MNSI that provide additional prognostic information for individuals with type 2 diabetes and CKD and/or CVD. If externally validated, these questions may be integrated into the clinical history to augment prediction of CV events in high-risk individuals with type 2 diabetes.

Individual serum saturated fatty acids and markers of chronic subclinical inflammation: the Insulin Resistance Atherosclerosis Study.

Recent evidence has documented distinct effects of individual saturated FAs (SFAs) on cardiometabolic outcomes, with potential protective effects from odd- and very long-chain SFAs (VLSFAs). Cross-sectional and prospective associations of individual serum SFAs (12:0, 14:0, 15:0, 16:0, 18:0, 20:0, 22:0, and total SFA) with proinflammatory biomarkers and adiponectin were investigated in 555 adults from the IRAS. Principal component analysis (PCA) of proinflammatory markers yielded three clusters: principal component (PC) 1: fibrinogen, white cell count, C-reactive protein; PC 2: plasminogen activator inhibitor-1 (PAI-1), TNF-α, IL-18; PC 3: IL-6 and IL-8. Cross-sectional analyses on proinflammatory PCs and adiponectin, and prospective analyses on 5 year PAI-1 and fibrinogen concentrations were conducted with multiple regression. Total SFA and 16:0 were positively associated with PC 1 and PC 2, and negatively associated with adiponectin. The 14:0 was positively associated with PC 1 and negatively associated with adiponectin. In contrast, 15:0, 20:0, and 22:0 were negatively associated with PC 2, and 20:0 and 22:0 were positively associated with adiponectin. The 18:0 was negatively associated with PC 3. Prospectively, 15:0, 18:0, 20:0, and 22:0 were negatively associated with 5 year PAI-1 concentrations. The results demonstrate that individual SFAs have distinct roles in subclinical inflammation, highlighting the unique metabolic impacts of individual SFAs.

Association of Directly Measured Plasma Free 25(OH)D With Insulin Sensitivity and Secretion: The IRAS Family Study.

Objectives: We aimed to compare the associations of directly measured plasma free 25-hydroxyvitamin D [25(OH)D] and total 25(OH)D concentrations with insulin sensitivity (SI) and ß-cell function in nondiabetic Hispanics and African Americans. We hypothesized that directly measured free 25(OH)D would be more strongly associated with these measures of glucose homeostasis and that associations would differ by race. Design: We studied 1189 nondiabetic participants in the Insulin Resistance Atherosclerosis Study Family Study using data from baseline examinations from 2000 to 2002. SI, acute insulin response, and disposition index (DI) were determined from frequently sampled intravenous glucose tolerance tests. Plasma free and total 25(OH)D concentrations were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. Results: The median concentrations of plasma free 25(OH)D were 3.46 pg/mL for Hispanics and 2.17 pg/mL for African Americans (P < 0.0001), whereas the median concentrations of plasma total 25(OH)D were 16 ng/mL for Hispanics and 10 ng/mL for African Americans (P < 0.0001). Plasma free and total 25(OH)D were both positively associated with SI and DI in generalized estimating equations adjusted for demographic and lifestyle factors. After further adjustment with body mass index, the associations were no longer statistically significant, except for a significant association between plasma free 25(OH)D and SI. There was no effect modification by ethnicity on any of the exposure-outcome associations. Conclusions: Our data showed that plasma free 25(OH)D had a slightly stronger association with SI compared with plasma total 25(OH)D, although the difference was modest and there were no marked differences in the associations between Hispanics and African Americans.

Noncardiovascular deaths are more common than cardiovascular deaths in patients with cardiovascular disease or cardiovascular risk factors and impaired glucose tolerance: Insights from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial.

BACKGROUND: Patients with impaired glucose tolerance have an elevated risk of cardiovascular (CV) death; however, the causes and risk factors associated with non-CV deaths are poorly understood. METHODS: The NAVIGATOR trial enrolled 9,306 participants with impaired glucose tolerance and CV disease or at high CV risk, with a median follow-up of 6.4years. Using this population, we identified (1) the proportion of deaths attributed to CV, non-CV, and unknown causes, and (2) the risk factors associated with non-CV death. RESULTS: During the NAVIGATOR trial follow-up, 622 patients died. Investigators reported 244 (39.2%) CV deaths, 313 (50.3%) non-CV deaths, and 65 (10.5%) deaths of unknown cause. Myocardial infarction was the leading cause of investigator-reported death (57/622 [9.2%]). Among non-CV deaths, the most commonly identified cause related to malignancy (177/313 [56.5%]). Using adjudicated causes of death, Cox proportional hazard models identified 3 independent prognostic markers that increased the risk of non-CV death: history of non-melanoma skin cancer (hazard ratio 2.67 [95% CI 1.65-4.33]; P<.0001), white blood cell count (1 unit >5000/mm3; 1.10 [1.02-1.18]; P=.011), and serum potassium levels (per 1mmol/L above any value; 1.67 [1.302.15]; P<.0001). CONCLUSIONS: Despite the high baseline CV risk among patients in the NAVIGATOR trial, the most common cause of death was non-CV. The high burden of non-CV death in this population has potential implications for future CV event-driven trials.

Updated risk factors should be used to predict development of diabetes.

AIMS: Predicting incident diabetes could inform treatment strategies for diabetes prevention, but the incremental benefit of recalculating risk using updated risk factors is unknown. We used baseline and 1-year data from the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) Trial to compare diabetes risk prediction using historical or updated clinical information. METHODS: Among non-diabetic participants reaching 1year of follow-up in NAVIGATOR, we compared the performance of the published baseline diabetes risk model with a "landmark" model incorporating risk factors updated at the 1-year time point. The C-statistic was used to compare model discrimination and reclassification analyses to demonstrate the relative accuracy of diabetes prediction. RESULTS: A total of 7527 participants remained non-diabetic at 1year, and 2375 developed diabetes during a median of 4years of follow-up. The C-statistic for the landmark model was higher (0.73 [95% CI 0.72-0.74]) than for the baseline model (0.67 [95% CI 0.66-0.68]). The landmark model improved classification to modest (<20%), moderate (20%-40%), and high (>40%) 4-year risk, with a net reclassification index of 0.14 (95% CI 0.10-0.16) and an integrated discrimination index of 0.01 (95% CI 0.003-0.013). CONCLUSIONS: Using historical clinical values to calculate diabetes risk reduces the accuracy of prediction. Diabetes risk calculations should be routinely updated to inform discussions about diabetes prevention at both the patient and population health levels.

Effect of valsartan on kidney outcomes in people with impaired glucose tolerance.

AIMS: To examine the effect of valsartan on kidney outcomes in patients with impaired glucose tolerance (IGT). METHODS: In a double-blind randomized trial, 9306 patients with IGT were assigned to valsartan (160 mg daily) or placebo. The co-primary endpoints were the development of diabetes and two composite cardiovascular outcomes. Prespecified renal endpoints included: the composite of renal death, end-stage renal disease (ESRD) or doubling of serum creatinine; estimated glomerular filtration rate (eGFR) ≤30 mL/min/1.73 m2 ; hospitalization for renal failure; and progression from normoalbuminuria to microalbuminuria, microalbuminuria to macroalbuminuria, and normoalbuminuria to macroalbuminuria. The median follow-up was 6.2 years. RESULTS: Valsartan reduced the incidence of diabetes but not cardiovascular events. In the valsartan group, 25/4631 patients (0.5%), vs 26/4675 (0.6%) patients in the placebo group, developed ESRD or experienced doubling of serum creatinine (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.55-1.66; P = .87). Few patients in either group developed an eGFR of ≤30 mL/min/1.73 m2 or had a renal hospitalization. Fewer patients on valsartan (237/4084 [5.8%]) than on placebo (342/4092 [8.4%]) developed microalbuminuria (HR 0.68, 95% CI 0.57-0.80; P < .0001), and fewer valsartan-treated patients developed macroalbuminuria. Overall, urinary albumin-to-creatinine ratio (UACR) was 11% lower with valsartan (95% CI 8-13; P < .0001) and 9% lower (95% CI 6-11; P < .0001) after adjusting for both glucose and blood pressure. CONCLUSIONS: The effect of valsartan on UACR was not wholly explained by change in blood pressure or glucose. Valsartan reduced the incidence of microalbuminuria in IGT without increasing the incidence of hyperkalaemia or renal dysfunction compared with placebo.

Novel Protein Glycan-Derived Markers of Systemic Inflammation and C-Reactive Protein in Relation to Glycemia, Insulin Resistance, and Insulin Secretion.

OBJECTIVE: N-acetylglucosamine/galactosamine (GlycA) and sialic acid (GlycB) moieties of glycosylated serum proteins are nonspecific measures of inflammation, but conclusive data on their relationship with insulin resistance or insulin secretion are missing. Therefore, we aimed to examine the relation of GlycA, GlycB, and C-reactive protein (CRP) to direct measures of insulin sensitivity (insulin sensitivity index [SI]) and insulin secretion (acute insulin response [AIR]). RESEARCH DESIGN AND METHODS: This study used cross-sectional analyses and included 1,225 participants with and without type 2 diabetes in the Insulin Resistance Atherosclerosis Study (IRAS). SI and AIR were measured using the frequently sampled intravenous glucose tolerance test, and GlycA and GlycB were measured using nuclear magnetic resonance spectroscopy. RESULTS: GlycA and GlycB had a strong correlation with CRP (r = 0.60 [P < 0.001] and r = 0.46 [P < 0.001], respectively). In a linear regression model with both GlycA and CRP as independent variables, GlycA (ß × 1 SD, -0.04 ± 0.02; P < 0.01) and CRP (-0.06 ± 0.02; P < 0.001) were independently associated with SI even after adjusting for demographics, smoking, physical activity, plasma glucose, and BMI. However, neither CRP nor GlycA had an independent relationship with AIR. CONCLUSIONS: GlycA may complement CRP in evaluating the relationship between inflammation, glucose tolerance, and insulin resistance.

Branched-Chain Amino Acids and Insulin Metabolism: The Insulin Resistance Atherosclerosis Study (IRAS).

OBJECTIVE: Recent studies using untargeted metabolomics approaches have suggested that plasma branched-chain amino acids (BCAAs) are associated with incident diabetes. However, little is known about the role of plasma BCAAs in metabolic abnormalities underlying diabetes and whether these relationships are consistent across ethnic populations at high risk for diabetes. We investigated the associations of BCAAs with insulin sensitivity (SI), acute insulin response (AIR), and metabolic clearance of insulin (MCRI) in a multiethnic cohort. RESEARCH DESIGN AND METHODS: In 685 participants without diabetes of the Insulin Resistance Atherosclerosis Study (IRAS) (290 Caucasians, 165 African Americans, and 230 Hispanics), we measured plasma BCAAs (sum of valine, leucine, and isoleucine) by mass spectrometry and SI, AIR, and MCRI by frequently sampled intravenous glucose tolerance tests. RESULTS: Elevated plasma BCAAs were inversely associated with SI and MCRI and positively associated with fasting insulin in regression models adjusted for potential confounders (ß = -0.0012 [95% CI -0.0018, -0.00059], P < 0.001 for SI; ß = -0.0013 [95% CI -0.0018, -0.00082], P < 0.001 for MCRI; and ß = 0.0015 [95% CI 0.0008, 0.0023], P < 0.001 for fasting insulin). The association of BCAA with SI was significantly modified by ethnicity, with the association only being significant in Caucasians and Hispanics. Elevated plasma BCAAs were associated with incident diabetes in Caucasians and Hispanics (multivariable-adjusted odds ratio per 1-SD increase in plasma BCAAs: 1.67 [95% CI 1.21, 2.29], P = 0.002) but not in African Americans. Plasma BCAAs were not associated with SI-adjusted AIR. CONCLUSIONS: Plasma BCAAs are associated with incident diabetes and underlying metabolic abnormalities, although the associations were generally stronger in Caucasians and Hispanics.

Lipoprotein heterogeneity may help to detect individuals with insulin resistance.

AIMS/HYPOTHESIS: The triacylglycerol (TG)-to-HDL-cholesterol ratio has been shown to detect insulin resistance. However, the added predictive value of a more comprehensive assessment of lipoprotein composition is unknown. METHODS: We analysed cross-sectional data from 882 non-diabetic participants in the Insulin Resistance Atherosclerosis Study (IRAS). Lipoproteins were measured by nuclear magnetic resonance (NMR) spectroscopy. Determined by the frequently sampled intravenous glucose tolerance test, insulin resistance was defined as the lowest sex-specific quartile of insulin sensitivity. RESULTS: The AUC of the receiver operating characteristic curve of HDL-cholesterol and TG levels for detecting insulin resistance was similar to that of the TG-to-HDL-cholesterol ratio (0.676 vs 0.673; p = 0.685), but smaller than the AUC of NMR-detected lipoproteins (0.676 vs 0.745; p < 0.001). NMR lipoproteins added discriminative value to HDL-cholesterol and TG levels (net reclassification improvement of 40.0%; p < 0.001; and integrated discrimination improvement of 9.5%; p < 0.001), with net benefit within predicted probabilities of between 10% and 50% by Vickers' decision-curve analysis. We also demonstrated additive value to demographic variables, BMI and levels of fasting glucose, TG, and HDL-cholesterol (net reclassification improvement of 14.0%; p < 0.001; and integrated discrimination improvement of 4.5%; p < 0.001). CONCLUSIONS/INTERPRETATION: NMR lipoproteins, which can be measured in the fasting state, add information to the TG and HDL-cholesterol ratio across a broad range on insulin resistance. Depending on the other risk factors of insulin resistance that are incorporated, NMR lipoproteins permit the correct reclassification of an additional 14-40% of individuals.

Prospective relationships between body weight and physical activity: an observational analysis from the NAVIGATOR study.

OBJECTIVES: While bidirectional relationships exist between body weight and physical activity, direction of causality remains uncertain and previous studies have been limited by self-reported activity or weight and small sample size. We investigated the prospective relationships between weight and physical activity. DESIGN: Observational analysis of data from the Nateglinide And Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) study, a double-blinded randomised clinical trial of nateglinide and valsartan, respectively. SETTING: Multinational study of 9306 participants. PARTICIPANTS: Participants with biochemically confirmed impaired glucose tolerance had annual measurements of both weight and step count using research grade pedometers, worn for 7 days consecutively. Along with randomisation to valsartan or placebo plus nateglinide or placebo, participants took part in a lifestyle modification programme. OUTCOME MEASURES: Longitudinal regression using weight as response value and physical activity as predictor value was conducted, adjusted for baseline covariates. Analysis was then repeated with physical activity as response value and weight as predictor value. Only participants with a response value preceded by at least three annual response values were included. RESULTS: Adequate data were available for 2811 (30%) of NAVIGATOR participants. Previous weight (χ(2)=16.8; p<0.0001), but not change in weight (χ(2)=0.1; p=0.71) was inversely associated with subsequent step count, indicating lower subsequent levels of physical activity in heavier individuals. Change in step count (χ(2)=5.9; p=0.02) but not previous step count (χ(2)=0.9; p=0.34) was inversely associated with subsequent weight. However, in the context of trajectories already established for weight (χ(2) for previous weight measurements 747.3; p<0.0001) and physical activity (χ(2) for previous step count 432.6; p<0.0001), these effects were of limited clinical importance. CONCLUSIONS: While a prospective bidirectional relationship was observed between weight and physical activity, the magnitude of any effect was very small in the context of natural trajectories already established for these variables. TRIAL REGISTRATION NUMBER: NCT00097786.

Mortality following a cardiovascular or renal event in patients with type 2 diabetes in the ALTITUDE trial.

AIMS: Patients with type 2 diabetes mellitus (T2DM) are at high risk of developing cardiovascular (CV) and renal disease. We examined the burden of, and risk of death following, CV and renal events in the Aliskiren Trial in Type 2 Diabetes Using Cardio-Renal Endpoints (ALTITUDE), a randomized trial of alikiren vs. placebo. METHODS AND RESULTS: We followed 8561 patients with T2DM and evidence of chronic kidney disease, CV disease, or both in ALTITUDE until the first non-fatal CV or renal event of myocardial infarction (MI), stroke, heart failure (HF), and end-stage renal disease (ESRD; initiation of dialysis, renal transplantation, or a serum creatinine concentration above 6.0 mg/dL) and then to death or censoring. Time-updated multivariable Cox models were used to estimate the relative risk of death following each event. In total 1008 patients (12%) experienced at least one first non-fatal CV or renal event (4.1% HF, 2.8% MI, 2.8% stroke, and 2.2% ESRD). Death occurred subsequently in 26.4% of those experiencing a first HF event, 29.7% of those experiencing an MI event, 23.7% of those experiencing a stroke, and 14.7% of those experiencing ESRD, and in 6.5% (488) of the 7553 patients (88%) who did not experience a non-fatal CV or renal event. Compared with patients who did not experience a non-fatal event, the adjusted hazard ratio for death was 5.9 (95% confidence interval 4.6-7.6) after HF, 9.7 (7.5-12.6) after MI, 7.1 (5.3-9.5) after stroke, and 5.8 (3.7-9.0) after ESRD. CONCLUSION: The majority of deaths occurred in patients who did not experience a non-fatal CV or renal event, although the risk of death was higher following an event. Our findings illustrate continuing opportunities to reduce morbidity and mortality in patients with type 2 diabetes.

Improving Adiponectin Levels in Individuals With Diabetes and Obesity: Insights From Look AHEAD.

OBJECTIVE: This study investigated whether fitness changes resulting from lifestyle interventions for weight loss may independently contribute to the improvement of low adiponectin levels in obese individuals with diabetes. RESEARCH DESIGN AND METHODS: Look AHEAD (Action for Health in Diabetes) randomized overweight/obese individuals with type 2 diabetes to intensive lifestyle intervention (ILI) for weight loss or to diabetes support and education (DSE). Total and high-molecular weight adiponectin (adiponectins), weight, and cardiorespiratory fitness (submaximal exercise stress test) were measured in 1,397 participants at baseline and at 1 year, when ILI was most intense. Regression analyses examined the associations of 1-year weight and fitness changes with change in adiponectins. RESULTS: ILI resulted in greater improvements in weight, fitness, and adiponectins at 1 year compared with DSE (P < 0.0001). Weight loss and improved fitness were each associated with changes in adiponectins in men and women (P < 0.001 for all), after adjusting for baseline adiponectins, demographics, clinical variables, and treatment arm. Weight loss contributed an additional 4-5% to the variance of change in adiponectins than did increased fitness in men; in women, the contributions of improved fitness (1% greater) and of weight loss were similar. When weight and fitness changes were both accounted for, weight loss in men and increased fitness in women retained their strong associations (P < 0.0001) with adiponectin change. CONCLUSIONS: Improvements in fitness and weight with ILI were favorably but distinctly associated with changes in adiponectin levels in overweight/obese men and women with diabetes. Future studies need to investigate whether sex-specific biological determinants contribute to the observed associations.

Lack of significant association between serum inflammatory cytokine profiles and the presence of colorectal adenoma.

BACKGROUND: Inflammatory cytokines in the colonic microenvironment have been shown to increase with advance colorectal cancer disease state. However, the contribution of inflammatory cytokines to pre-malignant disease, such as the formation of adenomas, is unclear. METHODS: Using the Milliplex® MAP Human Cytokine/ Chemokine Magnetic Bead Panel Immunoassay, serum cytokine and chemokine profiles were assayed among participants without an adenoma (n = 97) and those with an adenoma (n = 97) enrolled in the NCI-funded Insulin Resistance Atherosclerosis Colon Study. The concentrations of interleukin-10 (IL-10), IL-1ß, IL-6, IL-17A, IL-2, IL-4, IL-7, IL-12(p70), interferon-γ (IFN-γ), macrophage chemoattractant protein-1 (MCP-1), regulated on activation, normal T cell expressed and secreted (RANTES), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), granulocyte macrophage colony-stimulating factor (GM-CSF), and macrophage inflammatory protein-1ß (MIP-1ß) were determined. Multiple logistic regression analyses were used to evaluate the association between adenoma prevalence and cytokine levels. RESULTS: The presence of colorectal adenomas was not associated with significant increases in the systemic levels of proinflammatory (TNF-α, IL-6, IL-1ß) or T-cell polarizing (IL-12, IL-2, IL-10, IL-4, IL-17, IFN-γ) cytokines. Furthermore, MCP-1 and RANTES levels were equivalent in the serum of study participants with and without adenomas. CONCLUSIONS: These findings suggest colorectal adenoma prevalence may not be associated with significant alterations in systemic inflammation.

Glycated hemoglobin levels are mostly dependent on nonglycemic parameters in 9398 Finnish men without diabetes.

CONTEXT: Determinants of the variance in glycated hemoglobin (HbA1c) among individuals without type 2 diabetes remain largely unknown. OBJECTIVE: We investigated the determinants of HbA1c, fasting plasma glucose, and 2-hour glucose in an oral glucose tolerance test and the associations of these glycemic markers with insulin sensitivity and insulin secretion in Finnish men without type 2 diabetes. DESIGN AND SETTING: The design and setting were the cross-sectional population-based Metabolic Syndrome in Men study including 10 197 Finnish men, aged 45-70 years, and randomly selected from the population register of Kuopio, Eastern Finland. PARTICIPANTS: Participants were a total of 9398 men without type 2 diabetes or with newly diagnosed type 2 diabetes at baseline (mean age 57 ± 7 y; body mass index 27.0 ± 4.0 kg/m(2), mean ± SD) in the Metabolic Syndrome in Men study cohort. INTERVENTIONS: The intervention included an oral glucose tolerance test. MAIN OUTCOME MEASURES: Glycemic and nonglycemic determinants of the variance in HbA1c among participants without type 2 diabetes and the association of HbA1c with insulin secretion and insulin sensitivity were measured. RESULTS: Age, fasting plasma glucose, and high-sensitivity C-reactive protein were the strongest determinants of HbA1c, explaining 12% of the variance in HbA1c levels in participants without type 2 diabetes. Disposition index (insulin secretion) and the Matsuda insulin sensitivity index (insulin sensitivity) explained only less than 2% of the variance in HbA1c in the participants without type 2 diabetes. CONCLUSIONS: The variance in HbA1c among men without type 2 diabetes was largely determined by nonglycemic factors and only weakly by impaired insulin sensitivity and insulin secretion.

Fasting and OGTT-derived measures of insulin resistance as compared with the euglycemic-hyperinsulinemic clamp in nondiabetic Finnish offspring of type 2 diabetic individuals.

CONTEXT: It remains to be established which surrogate marker is the most predictive of insulin resistance. OBJECTIVE: We evaluated the incremental value of the Matsuda insulin sensitivity index (ISI) to homeostasis model assessment of insulin resistance (HOMA-IR) for detecting insulin resistance. DESIGN AND SETTING: This was a cross-sectional analysis of the EUGENE2 Kuopio cohort. PARTICIPANTS: Participants included 266 nondiabetic Finnish offspring of type 2 diabetic individuals (aged 24-50 years). MAIN OUTCOME MEASURES: Insulin resistance (the lowest whole-body glucose uptake quartile) was measured by the euglycemic-hyperinsulinemic clamp. We used the area under the receiver operating characteristic curve, an insensitive method to model improvement. Reclassification was assessed by the net reclassification improvement and integrated discrimination improvement. We generated four strata using, as cut points, the 0.05, 0.25, and 0.70 probabilities of having insulin resistance. These were observed probabilities at body mass index of 20, 27, and 35 kg/m(2), respectively. RESULTS: The area under the receiver operating characteristic curve of the Matsuda ISI based on 5 time points (0, 30, 60, 90, and 120 minutes) did not differ statistically from that of HOMA-IR (0.897 and 0.875, P = .080). However, the Matsuda ISI added incremental value to HOMA-IR for the detection of insulin-resistant individuals (net reclassification improvement, 26.2%, P < .001; integrated discrimination improvement, 6.3%, P < .001). A modified Matsuda ISI based on 4 time points (0, 30, 60, and 120 minutes) yielded similar results. CONCLUSION: The Matsuda ISI has additional value for the detection of insulin resistance beyond the ability of HOMA-IR. The Matsuda ISI reclassifies a net of 26% of individuals more appropriately.

Usefulness of measuring both body mass index and waist circumference for the estimation of visceral adiposity and related cardiometabolic risk profile (from the INSPIRE ME IAA study).

Despite its well-documented relation with visceral adiposity (VAT) and cardiometabolic risk (CMR), whether waist circumference (WC) should be measured in addition to body mass index (BMI) remains debated. This study tested the relevance of adding WC to BMI for the estimation of VAT and CMR. In the International Study of Prediction of Intra-abdominal Adiposity and Its Relationship with Cardiometabolic Risk/Intra-abdominal Adiposity, 297 physicians recruited 4,504 patients (29 countries). Both BMI and WC were measured, whereas VAT and liver fat were assessed by computed tomography. A composite CMR score was calculated. From the 4,109 patients included in the present analyses (20 ≤ BMI < 40 kg/m(2), 47% women), about 30% displayed discordant values for WC and BMI quintiles, despite a strong correlation between the 2 anthropometric variables (r = 0.87 and r = 0.84 for men and women, respectively, p <0.001). Within each single BMI unit, VAT and WC showed substantial variability between subjects (mean difference between 90th and 10th percentiles: 175 cm(2)/16 cm and 137 cm(2)/18 cm for VAT/WC in men and women, respectively). Within each BMI category, increasing gender-specific WC tertiles were associated with significantly higher VAT, liver fat, and with a more adverse CMR profile. In conclusion, this large international cardiometabolic study highlights the frequent discordance between BMI and WC, driven by the substantial variability in VAT for a given BMI. Within each BMI category, WC was cross-sectionally associated with VAT, liver fat, and CMR factors. Thus, WC allows a further refinement of the CMR related to any given BMI.

Serum pentadecanoic acid (15:0), a short-term marker of dairy food intake, is inversely associated with incident type 2 diabetes and its underlying disorders.

BACKGROUND: Growing evidence suggests that dairy consumption is associated with lower type 2 diabetes risk. However, observational studies have reported inconsistent results, and few have examined dairy's association with the underlying disorders of insulin resistance and ß-cell dysfunction. OBJECTIVE: We investigated the association of the dairy fatty acid biomarkers pentadecanoic acid (15:0) and trans-palmitoleic acid (trans 16:1n-7) with type 2 diabetes traits by evaluating 1) prospective associations with incident diabetes after 5 y of follow-up and 2) cross-sectional associations with directly measured insulin resistance and ß-cell dysfunction. DESIGN: The study analyzed 659 adults without diabetes at baseline from the triethnic multicenter Insulin Resistance Atherosclerosis Study (IRAS). Diabetes status was assessed by using oral-glucose-tolerance tests. Frequently sampled intravenous-glucose-tolerance tests measured insulin sensitivity (SI) and ß-cell function [disposition index (DI)]. Serum fatty acids were quantified by using gas chromatography. Logistic and linear regression models were adjusted for demographic, lifestyle, and dietary variables. RESULTS: Serum 15:0 was a significant biomarker for total dairy intake in the IRAS cohort. It was associated with a decreased incident diabetes risk (OR: 0.73, P = 0.02) and was positively associated with log SI (ß: 0.84, P = 0.03) and log DI (ß: 2.21, P = 0.02) in fully adjusted models. trans 16:1n-7 was a marker of total partially hydrogenated dietary fat intake and was not associated with outcomes in fully adjusted models. CONCLUSIONS: Serum 15:0, a marker of short-term intake of this fatty acid, was inversely associated with diabetes risk in this multiethnic cohort. This study may contribute to future recommendations regarding the benefits of dairy products on type 2 diabetes risk.