The 2019
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).
In this cross-sectional study, patients (
= 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).
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.
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.
Insulin resistance (IR) is associated with cardiovascular disease (CVD). However, insulin immunoassay variability and scarce research of the elderly have hindered the adoption of IR assessment for ...CVD prevention. We asked whether the probability of having IR p(IR)-derived from insulin and C-peptide mass-spectrometry assays-was associated with CVD in the elderly.
A random cohort was drawn from MPP, a population-based study of the elderly. After excluding those with missing data, CVD, or diabetes, 3645 participants (median age = 68) remained.
During follow-up (13.3 years), 794 incident CVD events were observed. p(IR) > 80% (n = 152) compared with p(IR) ≤ 80% was associated with incident CVD (HR = 1.51, 95% CI 1.12-2.05, p = 0.007) and CVD or all-cause mortality (HR = 1.43, 95% CI 1.16-1.77, p = 0.0009) after adjusting for age, sex, hypertension, smoking, HDL-cholesterol, total cholesterol, triglycerides, BMI, and prediabetes.
High p(IR) was associated with >50% greater risk of incident CVD. IR assessment in the elderly may be warranted.
In clinical trials, vitamin D supplementation has been reported to reduce serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) but not ...high-density lipoprotein cholesterol (HDL-C). In this cohort study we evaluated the association between changes in vitamin D (25-hydroxyvitamin D) and changes in lipid levels in a real-world setting. Changes in lipid levels over a 1-year period were evaluated among individuals whose vitamin D levels increased (group 1) or decreased (group 2) by ≥ 10 ng/mL in year 2018 versus 2017 (cohort 1; n = 5580), in 2019 versus 2018 (cohort 2, n = 6057), or in 2020 versus 2019 (cohort 3, n = 7249). In each cohort, levels of TC, LDL-C, and TG decreased in group 1 and increased in group 2. Between-group differences in average changes in the 3 cohorts ranged from 10.71 to 12.02 mg/dL for TC, from 7.42 to 8.95 mg/dL for LDL-C, and from 21.59 to 28.09 mg/dL for TG. These differences were significant after adjusting for age, sex, race, education, body mass index, blood pressure, smoking status, geographical location, and baseline levels of vitamin D and lipids (P < 0.001). Changes in vitamin D levels were not significantly associated with changes in HDL-C levels.
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.
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.
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.
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.
A simple, high-throughput, quantitative LC-MS/MS insulin assay traceable to the NIBSC standard has been successfully developed and validated.
Twenty-six states and the District of Columbia expanded Medicaid in January 2014 pursuant to the Affordable Care Act (ACA); 24 states did not. This created an opportunity to examine the impact of ...Medicaid expansion on the number of Medicaid patients with newly identified diabetes among enrollees (19-64 years of age) who had laboratory testing through Quest Diagnostics.
Newly identified diabetes was defined as an ICD-9 diagnosis code of 250.x (diabetes) or hemoglobin A1c of >6.4% (46 mmol/mol) within the first 6 months of a calendar year and the absence of both in the preceding calendar year within our data repository.
We identified 215,398 and 218,890 patients who met our definition of newly diagnosed diabetes within the first 6 months of 2013 (control period) and 2014 (study period), respectively (a 1.6% increase). We identified 26,237 Medicaid-enrolled patients with new diabetes in the control period vs. 29,673 in the study period: an increase of 13%. The number of Medicaid-enrolled patients with newly identified diabetes increased by 23% (14,625 vs. 18,020 patients) in the 26 states (and District of Columbia) that expanded Medicaid compared with an increase of 0.4% (11,612 vs. 11,653 patients) in the 24 states that did not expand Medicaid during this period. Similar differences were observed in younger and older adults and for both men and women.
This study suggests that in the states that expanded Medicaid under the ACA, an increased number of Medicaid patients with diabetes are being diagnosed and treated earlier. This could be anticipated to lead to better long-term outcomes.
The mechanisms leading to increased cardiovascular disease in patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis remain incompletely understood.
This study assessed ...HDL-bound proteins in patients with NAFLD with or without advanced fibrosis.
This cross-sectional study at a university hospital included 185 patients with or without type 2 diabetes (T2D). Patients underwent liver proton magnetic resonance spectroscopy to measure intrahepatic triglyceride accumulation and those with NAFLD underwent a percutaneous liver biopsy. Advanced lipid testing with lipoprotein subfraction measurements and targeted proteomics of HDL-bound proteins was performed.
Patients with and without advanced fibrosis had similar clinical characteristics, except for lower HDL-C (34 ± 8 vs 38 ± 9 mg/dL, P = 0.024) and higher prevalence of T2D in advanced fibrosis. Patients with advanced fibrosis had lower HDL particle number. A panel of 28 HDL-bound proteins were targeted and quantified by multiple reaction monitoring liquid chromatography-tandem mass spectrometry. Five proteins were found to be decreased in patients with advanced fibrosis (ApoC-I P < 0.001, ApoC-IV P = 0.012, ApoM P = 0.008, LCAT P = 0.014, and SAA4 P = 0.016). No differences were observed in these proteins in patients with vs without NAFLD or steatohepatitis. The pCAD index, associated with coronary artery disease and cardiovascular mortality, was significantly higher in patients with advanced fibrosis (97 ± 5 vs 86 ± 25, P = 0.04).
Patients with NAFLD with advanced fibrosis showed significant differences in HDL-bound protein levels; this translated into increased cardiovascular risk based on pCAD index. Different lipoprotein composition and function may explain the link between liver disease and increased cardiovascular mortality in these patients.
Introduction: Hyperinsulinemia is associated with future diabetes and cardiovascular disease. However, fasting insulin (FI) levels are rarely assessed in individuals with normoglycemia. To ...investigate the potential magnitude of undiagnosed hyperinsulinemia (FI >16 uIU/mL), we assessed the prevalence of hyperinsulinemia in individuals with normoglycemia (fasting glucose FG 70 to <100 mg/dL) in a nation-wide study of working-age individuals without diabetes.
Methods: The study included employees and spouses who participated in an annual health assessment program at Quest Diagnostics (October 2020 to February 2021). Those with diabetes, with FG <70 or ≥100 mg/dL, or with missing data were excluded. FI was measured by a mass-spectrometry assay standardized for the peptide content of WHO reference materials.
Results: Participants included 23,339 individuals (68% women) with normoglycemia (FG ≥70 or <100 mg/dL) and median age of 43 years (IQR 34 to 53). Hyperinsulinemia was observed in 7% (n =1,546) of participants. Of these, 1,064 individuals also participated in the health assessment program in a subsequent year and 46% (n =490) of them had persistent hyperinsulinemia. Obesity (BMI ≥30 kg/m2) was more common (83% vs. 71%) in those with persistent hyperinsulinemia than in those without (P <0.001) and they had lower HDL-C levels (45 vs 47 mg/dL, P <0.001) Age, sex, and triglyceride levels did not differ between those with and without persistent hyperinsulinemia (all P >0.05). Of the 490 individuals with persistent hyperinsulinemia, 76% (n =373) had persistent normoglycemia.
Conclusion: In a large population of working-age individuals, hyperinsulinemia was found in about 1 in 15 individuals with normoglycemia. Those with persistent hyperinsulinemia in a subsequent year were more likely to have obesity and lower HDL-C levels, and about 1 in 5 were no longer normoglycemic. Measurement of FI levels may have value in even apparently metabolically normal individuals.
Disclosure
J.Z.Louie: Employee; Quest Diagnostics. D.Shiffman: Consultant; Quest Diagnostics, Employee; Quest Diagnostics. J.B.Meigs: Consultant; Quest Diagnostics. M.J.Mcphaul: Employee; Quest Diagnostics.
Copeptin, co-secreted with arginine vasopressin, is regulated by osmotic and volume stimuli but also responds to intravenous arginine and insulin-induced hypoglycemia. The serum copeptin response to ...the latter agents has been studied in adults but only to a limited extent in children. The objective of this study was to describe the copeptin response to combined arginine and insulin in children with normal posterior pituitary function.
We conducted a prospective, single-arm assessment of serum copeptin concentrations in children (age 7-16 years, n = 38) undergoing growth hormone stimulation testing with an arginine-insulin tolerance test (AITT) for short stature or growth deceleration in a tertiary referral center. After overnight fasting, arginine (500 mg/kg) was administered between 0 and 30 min intravenously (IV) followed by insulin (0.1 units/kg IV) at 60 min. Copeptin serum concentrations were measured at baseline (0 min), at the post-arginine peak (60 min), and at the post-insulin peak (90 min; 30 min post-insulin), respectively. The main outcome was the peak copeptin concentration.
Mean ± SD copeptin concentrations increased from 9.9 ± 5.0 pmol/L at 0 min to 13.2 ± 5.8 pmol/L at 60 min (p < 0.0001 vs. 0 min) and 27.7 ± 14.2 pmol/L at 90 min (p < 0.0001 vs. 0 and 60 min). There was no significant correlation between copeptin concentrations and age, BMI, pubertal status, cortisol, growth hormone, or glucose concentrations.
Arginine and insulin appear to have an additive and consistent effect resulting in significant stimulation of copeptin secretion in children. The AITT may be a useful tool to evaluate for normal posterior pituitary function in this age-group, with potential implications for the evaluation of polyuria-polydipsia syndrome.
Measuring insulin-like growth factor-1 (IGF-1) is useful for assessing and managing growth-related disorders, such as acromegaly and growth hormone deficiency. High-resolution liquid ...chromatography–mass spectrometry (LC–MS) is used for measuring IGF-1 due to its molecular specificity, quantitative performance, well-characterized reference materials, and detailed age/sex-specific reference intervals. However, polymorphisms in the IGF1 gene may cause mass shifts in the polypeptide, which can impede quantitation and cause errors in clinical interpretation. We (1) developed a concept of “isotopic peak index”, which allows simultaneous monitoring of 15 IGF-1 variants by using only four m/z ratios; (2) developed a “relative retention time” parameter that allows distinction of previously unresolved variants; and (3) utilized tandem mass spectrometry (MS/MS) to distinguish between the most common pair of variants: isobaric A67T and A70T. All methods were validated with DNA sequencing. This approach identified six variants from the ExAC database, P66A, A67S, S34N, A38 V, A67T, and A70T; two previously reported V44M and A67V variants; and discovered six unreported variants, Y31H, S33P, R50Q, R56K, T41I, and A62T. Major improvements in our workflow include enhanced automation, avoiding detailed manual calculations that are prone to human error, and the ability to monitor more, and discover new, IGF-1 variants. The workflow provides a profile of a patient’s IGF-1 status and can be used to explore genotype–phenotype relationships in IGF-1 variants.
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