The relationship between IGF-I and -II concentrations and body composition at birth and over the first 2 months.

BACKGROUND: Insulin-like growth factor (IGF)-I and -II play an important role in prenatal growth. During the first 2 months from birth, body fat doubles, and rapid weight gain during this time increases future risk of cardiometabolic disease. The aim of this study was to determine whether IGF measurements at birth associate with body composition and the trajectory of its changes in the first 2 months. METHODS: Umbilical cord IGF-I and -II concentrations were measured in term infants. Air displacement plethysmography was performed at birth and 2 months. Fat mass (FM) and fat-free mass (FFM) were corrected for infant length (L) to FM/L3 and FFM/L2, respectively. RESULTS: In 601 (317 male) infants, IGF-I concentrations at birth were associated with FM/L3 and FFM/L2 Z-scores at birth (R2 = 0.05 and 0.04, respectively, P < 0.001), and IGF-II concentrations were associated with FFM/L2 Z-scores at birth (R2 = 0.01, P = 0.02). Lower IGF-I concentrations were weakly associated with increases in FM/L3 Z-scores over the first 2 months (R2 = 0.01, P = 0.003). CONCLUSION: IGF-I concentrations at birth are associated with adiposity and lean mass at birth and inversely with the trajectory of FM accumulation over the first 2 months. IGF-I measurements only account for a small amount of the variance in these measures.

Comparability of Lipoprotein Particle Number Concentrations Across ES-DMA, NMR, LC-MS/MS, Immunonephelometry, and VAP: In Search of a Candidate Reference Measurement Procedure for apoB and non-HDL-P Standardization.

BACKGROUND: Despite the usefulness of standard lipid parameters for cardiovascular disease risk assessment, undiagnosed residual risk remains high. Advanced lipoprotein testing (ALT) was developed to provide physicians with more predictive diagnostic tools. ALT methods separate and/or measure lipoproteins according to different parameters such as size, density, charge, or content, and equivalence of results across methods has not been demonstrated. METHODS: Through a split-sample study, 25 clinical specimens (CSs) were assayed in 10 laboratories before and after freezing using the major ALT methods for non-HDL particles (non-HDL-P) or apolipoprotein B-100 (apoB-100) measurements with the intent to assess their comparability in the current state of the art. RESULTS: The overall relative standard deviation (CV) of non-HDL-P and apoB-100 concentrations measured by electrospray differential mobility analysis, nuclear magnetic resonance, immunonephelometry, LC-MS/MS, and vertical autoprofile in the 25 frozen CSs was 14.1%. Within-method comparability was heterogeneous, and CV among 4 different LC-MS/MS methods was 11.4% for apoB-100. No significant effect of freezing and thawing was observed. CONCLUSIONS: This study demonstrates that ALT methods do not yet provide equivalent results for the measurement of non-HDL-P and apoB-100. The better agreement between methods harmonized to the WHO/IFCC reference material suggests that standardizing ALT methods by use of a common commutable calibrator will improve cross-platform comparability. This study provides further evidence that LC-MS/MS is the most suitable candidate reference measurement procedure to standardize apoB-100 measurement, as it would provide results with SI traceability. The absence of freezing and thawing effect suggests that frozen serum pools could be used as secondary reference materials.

Use of a metabolomic approach to non-invasively diagnose non-alcoholic fatty liver disease in patients with type 2 diabetes mellitus.

AIMS: To assess the utility of existing metabolomics scores to classify liver disease in patients with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: A total of 220 patients with T2DM were recruited. Patients underwent routine laboratory tests, liver proton magnetic resonance spectroscopy (1 H-MRS), a 75-g oral glucose tolerance test, and liver biopsy if 1 H-MRS findings indicated non-alcoholic fatty liver disease. A serum sample was blindly provided to OWL Metabolomics on which to run the OWLiver Care and OWLiver tests. RESULTS: When compared with liver biopsy, the OWLiver Care and OWLiver tests had a suboptimal performance in patients with T2DM (areas under the receiver-operating characteristic [AUROC] curve both <0.70). Given the discordance of these results in this heterogeneous, multiethnic cohort compared with those of a previous report in predominantly white patients without diabetes, we examined the influence of age, ethnicity and other variables on test performance. A specific subset of patients was selected to mirror the characteristics of the population used for the development of this model (ie, white patients without T2DM). Among white patients with good glycaemic control (glycated haemoglobin <53mmol/mol [or <7%]) and without cirrhosis, the AUROC curve was significantly improved (0.79 [CI 95%: 0.68-0.90]). Among white patients with lower insulin resistance (homeostatic model assessment of insulin resistance <3) and without cirrhosis, the AUROC was even higher: 0.87 (CI 95%: 0.76-0.97). CONCLUSIONS: There is a great need to develop non-invasive approaches to diagnose non-alcoholic steatohepatitis in patients with T2DM; models originally developed for patients without diabetes cannot be directly applied to patients with T2DM.

Atherogenic Lipoprotein Subfractions Determined by Ion Mobility and First Cardiovascular Events After Random Allocation to High-Intensity Statin or Placebo: The Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) Trial.

BACKGROUND: Cardiovascular disease (CVD) can occur in individuals with low low-density lipoprotein (LDL) cholesterol (LDL-C). We investigated whether detailed measures of LDL subfractions and other lipoproteins can be used to assess CVD risk in a population with both low LDL-C and high C-reactive protein who were randomized to high-intensity statin or placebo. METHODS AND RESULTS: In 11 186 Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) participants, we tested whether lipids, apolipoproteins, and ion mobility-measured particle concentrations at baseline and after random allocation to rosuvastatin 20 mg/d or placebo were associated with first CVD events (n=307) or CVD/all-cause death (n=522). In placebo-allocated participants, baseline LDL-C was not associated with CVD (adjusted hazard ratio [HR] per SD, 1.03; 95% confidence interval [CI], 0.88-1.21). In contrast, associations with CVD events were observed for baseline non-high-density lipoprotein (HDL) cholesterol (HR, 1.18; 95% CI, 1.01-1.38), apolipoprotein B (HR, 1.28; 95% CI, 1.11-1.48), and ion mobility-measured non-HDL particles (HR, 1.19; 95% CI, 1.05-1.35) and LDL particles (HR, 1.21; 95% CI, 1.07-1.37). Association with CVD events was also observed for several LDL and very-low-density lipoprotein subfractions but not for ion mobility-measured HDL subfractions. In statin-allocated participants, CVD events were associated with on-treatment LDL-C, non-HDL cholesterol, and apolipoprotein B; these were also associated with CVD/all-cause death, as were several LDL and very-low-density lipoprotein subfractions, albeit with a pattern of association that differed from the baseline risk. CONCLUSIONS: In JUPITER, baseline LDL-C was not associated with CVD events, in contrast with significant associations for non-HDL cholesterol and atherogenic particles: apolipoprotein B and ion mobility-measured non-HDL particles, LDL particles, and select subfractions of very-low-density lipoprotein particles and LDL particles. During high-intensity statin therapy, on-treatment levels of LDL-C and atherogenic particles were associated with residual risk of CVD/all-cause death. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239681.

Use of low density lipoprotein particle number levels as an aid in statin treatment decisions for intermediate risk patients: a cost-effectiveness analysis.

BACKGROUND: The 2013 ACC/AHA guideline recommended either no statin therapy or moderate-intensity statin therapy (MST) for intermediate risk patients-those with 5-7.5% 10-year risk and without cardiovascular disease (CVD), hypercholesterolemia or diabetes. The guideline further suggested that the therapy choice be based on patient-clinician discussions of risks and benefits. Since low-density lipoprotein particle (LDL-P) levels were reported to be associated with CVD independently of traditional risk factors in intermediate and low risk patients, we investigated the cost-effectiveness of using LDL-P levels to identify intermediate risk patients likely to benefit from initiating or intensifying statin therapy. METHODS: We evaluated 5 care strategies for intermediate risk patients. These included the strategies suggested by the guideline: no-statin therapy and MST. We compared each of these strategies to a related strategy that incorporated LDL-P testing. No-statin therapy was compared with the strategy of MST for those with high LDL-P levels and no statin therapy for all other patients (test-and-MST). MST was compared with the strategy of high-intensity statin therapy (HST) for those with high LDL-P levels and MST for all other patients (test-and-HST). We also evaluated the strategy of HST for all. Costs (payer perspective) and utilities were assessed over a 5-year time horizon in a Markov model of 100,000 hypothetical intermediate risk patients. RESULTS: HST dominated all other strategies, costing less and-despite causing 739 more cases of diabetes than did MST-resulting in more quality adjusted life-years (QALYs). For patient-clinician discussions that would otherwise lead to the MST strategy, we found the test-and-HST strategy reduced costs by $4.67 MM and resulted in 134 fewer CVD events and 115 additional QALYs. For patient-clinician discussions that would otherwise lead to no statin therapy, we found that the test-and-MST strategy reduced costs by $3.25 MM, resulted in 97 fewer CVD events and 44 additional QALYs. CONCLUSIONS: The HST strategy was cost saving and improved outcomes in intermediate risk patients. For patient and clinicians concerned about the adverse events associated with HST, using LDL-P levels to target intensified statin therapy could improve outcomes and reduce costs.

Lipoprotein(a) concentrations, rosuvastatin therapy, and residual vascular risk: an analysis from the JUPITER Trial (Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin).

BACKGROUND: Lipoprotein(a) [Lp(a)] is a low-density lipoprotein-like particle largely independent of known risk factors and predictive of cardiovascular disease. Statins may offset the risk associated with elevated Lp(a), but it is unknown whether Lp(a) is a determinant of residual risk in the setting of low low-density lipoprotein cholesterol after potent statin therapy. METHODS AND RESULTS: Baseline and on-treatment Lp(a) concentrations were assessed in 9612 multiethnic participants in the JUPITER trial (Justification for the Use of Statins in Prevention: An Intervention Trial Evaluating Rosuvastatin) before and after random allocation to rosuvastatin 20 mg/d or placebo, with outcomes reported for whites (n=7746). Lp(a) concentrations (median [25th-75th percentile], in nmol/L) were highest in blacks (60 [34-100]), then Asians (38 [18-60]), Hispanics (24 [11-46]), and whites (23 [10-50]; P<0.001). Although the median change in Lp(a) with rosuvastatin and placebo was zero, rosuvastatin nonetheless resulted in a small but statistically significant positive shift in the overall Lp(a) distribution (P<0.0001). Baseline Lp(a) concentrations were associated with incident cardiovascular disease (adjusted hazard ratio per 1-SD increment in Ln[Lp(a)], 1.18; 95% confidence interval, 1.03-1.34; P=0.02). Similarly, on-statin Lp(a) concentrations were associated with residual risk of cardiovascular disease (adjusted hazard ratio, 1.27; 95% confidence interval, 1.01-1.59; P=0.04), which was independent of low-density lipoprotein cholesterol and other factors. Rosuvastatin significantly reduced incident cardiovascular disease among participants with baseline Lp(a) greater than or equal to the median (hazard ratio, 0.62; 95% confidence interval, 0.43-0.90) and Lp(a) less than the median (hazard ratio, 0.46; 95% confidence interval, 0.30-0.72), with no evidence of interaction. Similar results were obtained when analyses included nonwhites. CONCLUSION: Among white JUPITER participants treated with potent statin therapy, Lp(a) was a significant determinant of residual risk. The magnitude of relative risk reduction with rosuvastatin was similar among participants with high or low Lp(a). CLINICAL TRIALS REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00239681.

Low circulating 25-hydroxyvitamin D concentrations are associated with defects in insulin action and insulin secretion in persons with prediabetes.

BACKGROUND: Individuals with prediabetes mellitus (PreDM) and low circulating 25-hydroxyvitamin D [25(OH)D] are at increased risk of type 2 diabetes mellitus (T2DM). OBJECTIVE: We aimed to determine whether low 25(OH)D concentrations are associated with defects in insulin action and insulin secretion in persons with PreDM. METHODS: In this cross-sectional study, we stratified 488 nondiabetic subjects as having PreDM or normal fasting glucose (NFG) and a 25(OH)D concentration ≤20 ng/mL (deficient) or >20 ng/mL (sufficient). We determined insulin resistance by steady state plasma glucose (SSPG) concentration and homeostasis model assessment of insulin resistance (HOMA-IR) and insulin secretion by homeostasis model assessment of ß-cell function (HOMA-ß). We compared insulin resistance and secretion measures in PreDM and NFG groups; 25(OH)D-deficient and 25(OH)D-sufficient groups; and PreDM-deficient, PreDM-sufficient, NFG-deficient, and NFG-sufficient subgroups, adjusting for age, sex, race, body mass index, multivitamin use, and season. RESULTS: In the PreDM group, mean SSPG concentration and HOMA-IR were higher and mean HOMA-ß was lower than in the NFG group (P < 0.001 for all comparisons). In the 25(OH)D-deficient group, mean SSPG concentration was higher (P < 0.001), but neither mean HOMA-IR nor HOMA-ß was significantly different from that in the 25(OH)D-sufficient group. In the PreDM-deficient subgroup, mean (95% CI) SSPG concentration was higher (P < 0.01) than in the PreDM-sufficient, NFG-deficient, and NFG-sufficient subgroups [192 (177-207) mg/dL vs. 166 (155-177) mg/dL, 148 (138-159) mg/dL, and 136 (127-144) mg/dL, respectively]. Despite greater insulin resistance, mean HOMA-ß was not significantly higher in the PreDM-deficient subgroup than in the PreDM-sufficient, NFG-deficient, and NFG-sufficient subgroups [98 (85-112) vs. 91 (82-101), 123 (112-136), and 115 (106-124), respectively]. CONCLUSION: Subjects with PreDM and low circulating 25(OH)D concentrations are the subgroup of nondiabetic individuals who are the most insulin resistant and have impaired ß-cell function, attributes that put them at enhanced risk of T2DM.

A randomized, double blind, placebo-controlled pilot trial of the safety and efficacy of atorvastatin in children with elevated low-density lipoprotein cholesterol (LDL-C) and type 1 diabetes.

BACKGROUND: Children with type 1 diabetes (T1D) and elevated LDL-C have an increased risk for cardiovascular disease, a process that can begin in childhood. OBJECTIVE: To assess the safety and efficacy of atorvastatin improving lipid profiles in children with T1D and elevated LDL-C. SUBJECTS: Sixty children (31M/29F) with T1D, mean age: 15 ± 0.3 yr, mean diabetes duration: 6.8 ± 0.5 yr, HbA(1c) : 8.8 ± 0.2%, with mean LDL-C 124 ± 4.0mg/dl were recruited. METHODS: After a 3-month run-in period, subjects were randomized double-blindly to atorvastatin or placebo for 6 months. Lipoprotein subfractions were measured by ion mobility and glucose control by HbA1C; continuous glucose monitors were worn quarterly. RESULTS: After a run-in period, 42 subjects were randomized. There were decreases in total cholesterol (-21%), LDL-C (-32%), non-HDL-C (-31%) and apoB (-26%) in the atorvastatin group versus placebo (p < 0.001). Lipoprotein subparticles (LDL-large 1 and 2A, IDL-large and small, VLDL- medium and small) decreased with statins (p < 0.03 all). Insulin sensitivity scores remained constant in both groups and correlated inversely with apoB (r = -0.312 p = 0.039) and small LDL 3A (r = -0.404 p = 0.007). One subject had asymptomatic elevation of creatinine kinase which normalized after atorvastatin discontinuation. CONCLUSIONS: Atorvastatin lowered LDL-C, apoB, and atherogenic lipoprotein subparticles in children with T1D and elevated LDL-C without worsening insulin resistance. The drug was well tolerated and safe. Long-term studies would provide better insight on the impact of these interventions in the development of cardiovascular disease in children with diabetes.

Quantitative insulin analysis using liquid chromatography-tandem mass spectrometry in a high-throughput clinical laboratory.

BACKGROUND: Circulating insulin concentrations reflect the amount of endogenous insulin produced by the pancreas and can be monitored to check for insulin resistance. Insulin is commonly measured using immunochemiluminometric assays (ICMA). Unfortunately, differing crossreactivities of the various ICMA antibodies have led to variability in assay results. In contrast, liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based approaches can provide a highly specific alternative to immunoassays. METHODS: Insulin was extracted from patient serum and reduced to liberate the insulin B chain. Subsequent resolution of the peptide was achieved by LC coupled to triple-quadrupole MS. Selected-reaction monitoring of B-chain transitions was used for quantification. Recombinant human insulin was used as a calibrator and was compared against the National Institute for Biological Standards and Control (NIBSC) reference standard. Bovine insulin and a stable isotopic-labeled ((13)C/(15)N) human insulin B chain were used and compared as internal standards. RESULTS: The LC-MS/MS assay described herein has been validated according to CLIA guidelines with a limit of detection of 1.8 µIU/mL (10.8 pmol/L) and a limit of quantitation of 3 µIU/mL (18.0 pmol/L). A correlation between the LC-MS/MS assay and a US Food and Drug Administration-approved ICMA was completed for patient samples and the resulting Deming regression revealed good agreement. A reference interval for the assay was established. CONCLUSIONS: A simple, high-throughput, quantitative LC-MS/MS insulin assay traceable to the NIBSC standard has been successfully developed and validated.

Bile acid concentration reference ranges in a pregnant Latina population.

OBJECTIVE: The total bile acid (TBA) concentration criterion for diagnosing intrahepatic cholestasis of pregnancy varies in the published literature. The purpose of this study was to establish pregnancy-specific reference ranges for the TBA concentration among Latina women. STUDY DESIGN: Self-identified Latina women (n = 211) over 18 years of age with a singleton pregnancy were recruited and had random serum samples drawn during the second and third trimesters. The total and fractionated bile acid concentrations were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and reference ranges were calculated. Laboratory-provided general reference ranges from a general population of adult men and nonpregnant women were used for comparison. RESULTS: The TBA reference range for our Latina pregnant population (<8.5 µmol/L) was markedly lower than the laboratory-provided reference range (4.5 to 19.2 µmol/L). CONCLUSION: These data suggest that the upper TBA concentration reference range in our Latina pregnant population is 8.5 µmol/L, based on LC-MS/MS measurements.

Lipoprotein subfractions by ion mobility in lean and obese children.

OBJECTIVE: To establish normative data for lipoprotein subfractions using a novel ion mobility assay in healthy lean children and to compare their data with those of obese children preselected with normal glucose, blood pressure, and relatively normal lipids. STUDY DESIGN: Fasting blood samples in 162 children aged 7.0-18.9 years (75 lean [body mass index: 18.6 ± 6.6 kg/m(2)] and 87 obese [body mass index: 31.7 ± 5.4 kg/m(2)]) were analyzed. Correlation of lipoprotein subfractions with anthropometric and laboratory markers was performed. Principal component analysis was used to avoid using correlated variables. RESULTS: Normative data for lipid subfractions were obtained in healthy children. Lean children had higher high-density lipoprotein (HDL)-large (76%), HDL-small (13%), and HDL-total (27%) compared with obese (P < .01), and lower low-density lipoprotein (LDL)-medium (-30%, P < .01) and medium + small (-21%, P = .02) as well as LDL-total (-13%, P = .035). In both groups, the LDL component was higher in males and pubertal children (P < .01). Prepubertal children had a higher HDL component than pubertal ones (P < .004). Adjusting for sex and pubertal status LDL component was positively, and HDL component negatively, correlated with obesity (P < .004). CONCLUSIONS: Despite relatively normal triglycerides and cholesterol measured with standard assays at screening, ion mobility analysis showed significant differences in lipid and apolipoprotein subfractions between lean and obese children, even those prepubertal. Long-term, prospective follow-up may better characterize the predictability of lipid subfractions for future cardiovascular disease risk in children.

Testosterone reference ranges in normally cycling healthy premenopausal women.

INTRODUCTION: At present, there are no well-accepted reference ranges for serum testosterone concentrations in women. AIM: The aim of this study was to determine the reference ranges for serum testosterone and sex hormone-binding globulin (SHBG) in premenopausal women with normal menstrual cycles. METHODS: We measured serum total, free, and bioavailable testosterone and SHBG concentrations in 161 healthy, normally cycling women (18-49 years). Morning blood samples were collected during follicular, mid-cycle, and luteal phases of the menstrual cycle and analyzed using validated methods. Mean, median, and weighted average hormone levels across menstrual cycle phases as well as percentiles for a typical 30-year-old woman were determined. MAIN OUTCOME MEASURES: Age-related serum levels of total, free, and bioavailable testosterone and SHBG levels in normally cycling premenopausal women. RESULTS: Serum testosterone concentrations exhibited an age-related decline, whereas SHBG remained relatively stable across studied age ranges. Reference ranges for total, free, and bioavailable testosterone and SHBG were established using 5th and 95th percentiles. The estimated 5th and 95th percentiles for a 30-year-old woman were: testosterone, 15-46 ng/dL (520-1595 pmol/L); free testosterone, 1.2-6.4 pg/mL (4.16-22.2 pmol/L); calculated free testosterone, 1.3-5.6 pg/mL (4.5-19.4 pmol/L); bioavailable testosterone, 1.12-7.62 ng/dL (38.8-264.21 pmol/L); and SHBG 18-86 nmol/L. The variations of hormones and SHBG across menstrual cycle were consistent with previous literature. CONCLUSIONS: Reference ranges for free, total, and bioavailable testosterone and SHBG were established in premenopausal women using validated immunoassays and an adequate number of subjects consistent with recommendations by the National Committee for Clinical Laboratory Standards. The increase in testosterone in the mid-cycle period is relatively small compared with the overall variability, so these reference ranges can be applied irrespective of the day in the menstrual cycle the sample has been taken.

Ion mobility analysis of lipoprotein subfractions identifies three independent axes of cardiovascular risk.

OBJECTIVE: Whereas epidemiological studies show that levels of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) predict incident cardiovascular disease (CVD), there is limited evidence relating lipoprotein subfractions and composite measures of subfractions to risk for CVD in prospective cohort studies. METHODS AND RESULTS: We tested whether combinations of lipoprotein subfractions independently predict CVD in a prospective cohort of 4594 initially healthy men and women (the Malmö Diet and Cancer Study, mean follow-up 12.2 years, 377 incident cardiovascular events). Plasma lipoproteins and lipoprotein subfractions were measured at baseline with a novel high-resolution ion mobility technique. Principal component analysis (PCA) of subfraction concentrations identified 3 major independent (ie, zero correlation) components of CVD risk, one representing LDL-associated risk, a second representing HDL-associated protection, and the third representing a pattern of decreased large HDL, increased small/medium LDL, and increased triglycerides. The last corresponds to the previously described "atherogenic lipoprotein phenotype." Several genes that may underlie this phenotype-CETP, LIPC, GALNT2, MLXIPL, APOA1/A5, LPL-are suggested by SNPs associated with the combination of small/medium LDL and large HDL. CONCLUSIONS: PCA on lipoprotein subfractions yielded three independent components of CVD risk. Genetic analyses suggest these components represent independent mechanistic pathways for development of CVD.

Performance of Plasma Biomarkers and Diagnostic Panels for Nonalcoholic Steatohepatitis and Advanced Fibrosis in Patients With Type 2 Diabetes.

OBJECTIVE: The 2019 Standards of Medical Care in Diabetes suggested that patients with nonalcoholic fatty liver disease (NAFLD) should be evaluated for liver fibrosis. However, the performance of noninvasive clinical models/scores and plasma biomarkers for the diagnosis of nonalcoholic steatohepatitis (NASH) and advanced fibrosis has not been carefully assessed in patients with type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS: In this cross-sectional study, patients (n = 213) had a liver MRS, and those with a diagnosis of NAFLD underwent a percutaneous liver biopsy. Several noninvasive clinical models/scores and plasma biomarkers were measured to identify NASH and advanced fibrosis (NASH: ALT, cytokeratin-18, NashTest 2, HAIR, BARD, and OWLiver; advanced fibrosis: AST, fragments of propeptide of type III procollagen [PRO-C3], FIB-4, APRI, NAFLD fibrosis score, and FibroTest). RESULTS: None of the noninvasive tools assessed for the diagnosis of NASH in patients with T2DM had an optimum performance (all areas under the curve [AUCs] <0.80). Of note, none of the panels or biomarkers was able to outperform plasma ALT (AUC 0.78 [95% CI 0.71-0.84]). Performance was better to diagnose advanced fibrosis, in which plasma PRO-C3, AST, and APRI showed better results than the other approaches (AUC 0.90 [0.85-0.95], 0.85 [0.80-0.91], and 0.86 [0.80-0.91], respectively). Again, none of the approaches did significantly better than plasma AST. Sequential use of plasma AST and other noninvasive tests may help in limiting the number of liver biopsies required to identify patients with advanced fibrosis. CONCLUSIONS: Performance of noninvasive clinical models/scores and plasma biomarkers for the diagnosis of NASH or advanced fibrosis was suboptimal in patients with T2DM. Combination of multiple tests may provide an alternative to minimize the need for liver biopsies to detect fibrosis in these patients.

Comparison of nonfasting and fasting lipoprotein subfractions and size in 15,397 apparently healthy individuals: An analysis from the VITamin D and OmegA-3 TriaL.

BACKGROUND: Elevated postprandial triglycerides reflect a proatherogenic milieu, but underlying mechanisms are unclear. OBJECTIVE: We examined differences between fasting and nonfasting profiles of directly measured lipoprotein size and subfractions to assess if postprandial triglycerides reflected increases in very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and remnants, or small dense lipid depleted LDL (sdLDL) particles. METHODS: We conducted a cross-sectional analysis of 15,397 participants (10,135 fasting; 5262 nonfasting [<8 hours since last meal]) from the VITamin D and OmegA-3 TriaL. Baseline cholesterol subfractions were measured by the vertical auto profile method and particle subfractions by ion mobility. We performed multivariable linear regression adjusting for cardiovascular and lipoprotein-modifying risk factors. RESULTS: Mean age (SD) was 68.0 years (±7.0), with 50.9% women. Adjusted mean triglyceride concentrations were higher nonfasting by 17.8 ± 1.3%, with higher nonfasting levels of directly measured VLDL cholesterol (by 3.5 ± 0.6%) and total VLDL particles (by 2.0 ± 0.7%), specifically large VLDL (by 12.3 ± 1.3%) and medium VLDL particles (by 5.3 ± 0.8%), all P < .001. By contrast, lower concentrations of low density lipoprotein (LDL) and IDL cholesterol and particles were noted for nonfasting participants. sdLDL cholesterol levels and particle concentrations showed no statistically significant difference by fasting status (-1.3 ± 2.1% and 0.07 ± 0.6%, respectively, P > .05). CONCLUSIONS: Directly measured particle and cholesterol concentrations of VLDL, not sdLDL, were higher nonfasting and may partly contribute to the proatherogenicity of postprandial hypertriglyceridemia. These differences, although statistically significant, were small and may not fully explain the increased risk of postprandial hypertriglyceridemia.

Performance of the SteatoTest, ActiTest, NashTest and FibroTest in a multiethnic cohort of patients with type 2 diabetes mellitus.

Fibromax is a diagnostic tool composed of the combination of 4 non-invasive biomarker panels for the diagnosis of steatosis (SteatoTest), necrosis and inflammation (ActiTest and NashTest-2) and fibrosis (FibroTest). The purpose of this study was to assess the performance of these biomarker panels in patients with type 2 diabetes mellitus (T2DM). All patients underwent routine labs, a 75 g oral glucose tolerance test, a liver proton magnetic resonance spectroscopy (1H-MRS) to measure intrahepatic triglyceride content, and a percutaneous liver biopsy to establish the diagnosis of non-alcoholic steatohepatitis (NASH) and to grade and stage the disease in those patients with non-alcoholic fatty liver disease (NAFLD) by 1H-MRS. For determination of the scores, plasma samples were blindly provided to establish the SteatoTest, ActiTest, NashTest-2 and FibroTest scores. A total of 220 patients with T2DM were included in this study. When the ability of the SteatoTest to identify patients with T2DM with NAFLD by 1H-MRS was assessed, the overall performance expressed as the area under the receiver operating characteristic curve was 0.73 (95% CI 0.65 to 0.81). The performance of the ActiTest and NashTest-2 to diagnose definite NASH among patients with T2DM was 0.70 (95% CI 0.63 to 0.77) and 0.69 (95% CI 0.62 to 0.76), respectively. Regarding the FibroTest score, its performance to identify patients with moderate or advanced fibrosis was 0.67 (95% CI 0.58 to 0.76) and 0.72 (95% CI 0.61 to 0.83), respectively. Non-invasive panels for the diagnosis of steatosis, NASH and/or fibrosis, which were developed and validated in non-diabetic cohorts, underperformed when applied to a large cohort of patients with T2DM. Results from non-diabetic populations should not be extrapolated to patients with T2DM.

Direct determination of lipoprotein particle sizes and concentrations by ion mobility analysis.

BACKGROUND: Current methods for measuring the concentrations of lipoprotein particles and their distributions in particle subpopulations are not standardized. We describe here and validate a new gas-phase differential electrophoretic macromolecular mobility-based method (ion mobility, or IM) for direct quantification of lipoprotein particles, from small, dense HDL to large, buoyant, very-low-density lipoprotein (VLDL). METHODS: After an ultracentrifugation step to remove albumin, we determined the size and concentrations of lipoprotein particles in serum samples using IM. Scan time is 2 min and covers a particle range of 17.2-540.0 A. After scanning, data are pooled by totaling the particle number across a predetermined size range that corresponds to particular lipoprotein subclasses. IM results were correlated with those of standard methods for cholesterol and apolipoprotein analysis. RESULTS: Intra- and interassay coefficients of variation for LDL particle size were <1.0%. The intra- and interassay variation for LDL and HDL particle subfraction measurements was <20%. IM-measured non-HDL correlated well with apolipoprotein B (r = 0.92). CONCLUSIONS: The IM method provides accurate, reproducible, direct determination of size and concentration for a broad range of lipoprotein particles. Use of this methodology in studies of patients with cardiovascular disease and other pathologic states will permit testing of its clinical utility for risk assessment and management of these conditions.

A cross-sectional study of bone turnover markers in healthy premenopausal women.

BACKGROUND: Biochemical markers of bone turnover (BTMs) provide useful information in the diagnosis and management of metabolic bone diseases. Currently, there exist few published reference ranges for bone markers in healthy premenopausal women using the newer, automated assays of bone turnover. This cross-sectional study of healthy premenopausal women was performed to determine reference ranges for four different markers of bone turnover and to compare reference ranges in users and non-users of oral contraceptives (OCs). METHODS: Urinary N-telopeptide of type 1 collagen (NTX) was determined from fasting second morning-void urine of healthy premenopausal women. In addition, fasting serum was collected for determination of C-telopeptide of type I collagen (CTX), bone-specific alkaline phosphatase (bone ALP), and N-terminal propeptide of type 1 procollagen (PINP). Subjects underwent central dual energy X-ray absorptiometry and completed a questionnaire regarding medical history and activities known to affect bone health. RESULTS: Serum and urine samples were collected from 237 healthy premenopausal women (119 OC users and 118 non-users) between the ages of 28 and 45 years. The mean age of subjects was 37 years, with a mean bone mineral density T-score of -0.1 at the lumbar spine and 0.0 at the total hip. Logarithmic transformation produced normal distributions for all markers but NTX. Mid-95% ranges for each marker were generally consistent with those reported by manufacturers. For each BTM examined, values were skewed toward the lower end of the range. Median NTX levels for OC users and non-users were 16.0 and 29.0 nmol/mmol creatinine, respectively. The mid-95% ranges for NTX in OC users and non-users were 3-60 and 4-64 nmol/mmol creatinine, respectively. Median levels of CTX, bone ALP, and PINP were also lower in OC users than non-users. The mean level of each BTM was significantly lower in OC users than non-users (P<0.01), whereas reference ranges (geometric mean+/-2 SD) were somewhat similar for the two groups. CONCLUSION: Values obtained from this well-characterized population provide reference ranges for BTMs in healthy premenopausal women. Median and mean BTM levels for OC users were consistently lower compared with non-users; thus, separate reference ranges are required for these two groups of premenopausal women. The relevance of premenopausal reference ranges for postmenopausal women remains uncertain.

LDL subfractions are associated with incident cardiovascular disease in the Malmö Prevention Project Study.

BACKGROUND AND AIMS: After assessing the risk for cardiovascular disease (CVD) based on traditional risk factors, decisions concerning lipid lowering therapy might remain uncertain. To investigate whether lipoprotein subfraction levels could aid these decisions, we assessed the association between lipoprotein subfractions and CVD, after adjustment for traditional risk factors including standard lipids. METHODS: Using a case-cohort design, participants were randomly drawn from the Malmö Prevention Project (MPP), a population-based prospective study of 18,240 participants, and supplemented with additional incident CVD events (5764 participants, 1784 CVD events). RESULTS: Low density lipoprotein particle number (LDL-P) and individual subfractions ranging in size from very-small to large were associated with CVD (continuous p value (pcont) < 0.001) while adjusting for age, sex, hypertension, smoking, and diabetes. After further adjustment for LDL-C, HDL-C, and triglycerides, very small LDL subfraction (b) (LDL-VS (b)) remained associated with CVD (HR = 1.23, 95% CI, 1.06 to 1.43 for top vs. bottom quartile, pcont = 0.03). Among participants with low/intermediate risk [without diabetes and with LDL-C <3.36 mmol/L (<130 mg/dL)], the fully adjusted HR for LDL-small (top vs. bottom quartile) was 1.48 (95% CI 1.02 to 2.17, pcont = 0.03). Among those with very-high risk (>20% 10-year risk of CVD), LDL-VS(a) and LDL-VS(b) were associated with CVD in fully adjusted models (HR = 1.37, 95% CI 1.12 to 1.67 and HR = 1.28, 95% CI 1.07 to 1.53, respectively, pcont≤0.03). CONCLUSIONS: Smaller LDL particles are associated with incident CVD independently of traditional risk factors, including standard lipids, in participants with low/intermediate and very-high risk, who might benefit from improved risk assessment.