A Cross-Sectional Study of Glomerular Hyperfiltration in Polycystic Ovary Syndrome

Glomerular hyperfiltration (GH) has been reported to be higher in women with polycystic ovary syndrome (PCOS) and is an independent risk factor for renal function deterioration, metabolic, and cardiovascular disease. The aim of this study was to determine GH in type A PCOS subjects and to identify whether inflammatory markers, markers of CKD, renal tubule injury markers, and complement system proteins were associated. In addition, a secondary cohort study was performed to determine if the eGFR had altered over time. In this comparative cross-sectional analysis, demographic, metabolic, and proteomic data from Caucasian women aged 18-40 years from a PCOS Biobank (137 with PCOS, 97 controls) was analyzed. Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was undertaken for inflammatory proteins, serum markers of chronic kidney disease (CKD), tubular renal injury markers, and complement system proteins. A total of 44.5% of the PCOS cohort had GH (eGFR ≥ 126 mL/min/1.73 m2 (n = 55)), and 12% (n = 17) eGFR ≥ 142 mL/min/1.73 m2 (super-GH(SGH)). PCOS-GH women were younger and had lower creatinine and urea versus PCOS-nonGH. C-reactive protein (CRP), white cell count (WCC), and systolic blood pressure (SBP) were higher in PCOS versus controls, but CRP correlated only with PCOS-SGH alone. Complement protein changes were seen between controls and PCOS-nonGH, and decay-accelerator factor (DAF) was decreased between PCOS-nonGH and PCOS-GSGH (p < 0.05). CRP correlated with eGFR in the PCOS-SGH group, but not with other inflammatory or complement parameters. Cystatin-c (a marker of CKD) was reduced between PCOS-nonGH and PCOS-GSGH (p < 0.05). No differences in tubular renal injury markers were found. A secondary cohort notes review of the biobank subjects 8.2-9.6 years later showed a reduction in eGFR: controls -6.4 ± 12.6 mL/min/1.73 m2 (-5.3 ± 11.5%; decrease 0.65%/year); PCOS-nonGH -11.3 ± 13.7 mL/min/1.73 m2 (-9.7 ± 12.2%; p < 0.05, decrease 1%/year); PCOS-GH (eGFR 126-140 mL/min/17.3 m2) -27.1 ± 12.8 mL/min/1.73 m2 (-19.1 ± 8.7%; p < 0.0001, decrease 2%/year); PCOS-SGH (eGFR ≥ 142 mL/min/17.3 m2) -33.7 ± 8.9 mL/min/17.3 m2 (-22.8 ± 6.0%; p < 0.0001, decrease 3.5%/year); PCOS-nonGH eGFR versus PCOS-GH and PCOS-SGH, p < 0.001; no difference PCOS-GH versus PCOS-SGH. GH was associated with PCOS and did not appear mediated through tubular renal injury; however, cystatin-c and DAF were decreased, and CRP correlated positively with PCOS-SGH, suggesting inflammation may be involved at higher GH. There were progressive eGFR decrements for PCOS-nonGH, PCOS-GH, and PCOS-SGH in the follow-up period which, in the presence of additional factors affecting renal function, may be clinically important in the development of CKD in PCOS.

Using nephropathy as an outcome to determine the HbA1c diagnostic threshold for type 2 diabetes

OBJECTIVE

The hemoglobin A1c (HbA1c) diagnostic threshold for type 2 diabetes (T2D) of 6.5 % (48 mmol/mol) was based on the prevalence of retinopathy found in populations not known to have T2D. It is unclear if nephropathy has a similar HbA1c threshold, partly because it is a rarer complication of early diabetes. This cohort study investigated a very high diabetes prevalence population to determine if a better diagnostic HbA1c value can be established for predicting nephropathy rather than retinopathy in subjects without T2D.

METHODS

The urine albumin:creatinine ratios (UACRs) of 2920 healthy individuals from the Qatar Biobank who had an HbA1c ≥ 5.6 %. were studied. Nephropathy was defined as a UACR≥30 mg/g and its prediction by HbA1c was assessed using cut-points ranging from 5.7 to 7.0 % to dichotomize high from low HbA1c.

RESULTS

Although there was a significant trend for an increased prevalence of abnormal UACR as the HbA1c threshold increased (p < 0.01), significance was due mostly to subjects with HbA1c ≥ 7.0 % (53 mmol/mol). The odds ratios for abnormal UACR were similar over the 5.7-6.9 % HbA1c threshold range, with a narrow odds ratio range of 1.2-1.6. Utilizing area-under-receiver-operating characteristic curves, no HbA1c threshold <7.0 % was identified as the best predictor of nephropathy.

CONCLUSION

Even in a population with a high prevalence of known and unknown diabetes, no HbA1c threshold <7.0 % could be found predicting an increased prevalence of nephropathy. This means there is not a requirement to change the existing retinopathy-based HbA1c threshold of 6.5 % to also accommodate diabetes nephropathy risk.

Performance of renin assays in selecting fludrocortisone dose in children with adrenal disorders

Children with salt-wasting adrenal insufficiency are managed with glucocorticoid and mineralocorticoid replacement. Measurement of renin activity or concentration alongside blood electrolyte levels is used to monitor the adequacy of mineralocorticoid replacement. Our unit changed from using renin activity to renin concentration and carried out a service review to assess whether this influenced decision-making for fludrocortisone dosing. In total, 50 measurements of plasma renin activity and 50 of renin concentration were analysed on separate cohorts before and after the assay change, with values standardised to multiples of the upper limit of normal (MoU) to allow comparison between assays. We were more likely to increase the fludrocortisone dose for a raised renin concentration than a raised renin activity. The renin concentration MoU was more strongly related to plasma sodium (negatively) and 17α-hydroxyprogesterone (17α-OHP) (positively) than the renin activity MoU. Using a MoU cut-off of 1.5, a decision to increase the dose of fludrocortisone was more likely to be made when using the renin concentration assay compared with the activity assay. Using a cut-off of 40 nmol/L for 17α-OHP, a decision not to change the fludrocortisone dose when 17α-OHP was <40 was more likely when using the renin concentration assay. For both assays, a plasma sodium <140 mmol/L was more likely to lead to a fludrocortisone dose increase, and most likely for the renin concentration assay. Overall, the decision to adjust fludrocortisone dose in this cohort of children with adrenal insufficiency was better supported by the biochemical parameters when based on renin concentration results and clinical status.

Assay error detection when using common quality control targets across multiple instruments: An analysis using simulated and real-world data

BACKGROUND

Clinical laboratories frequently implement the same tests and internal quality control (QC) rules on identical instruments. It is unclear whether individual QC targets for each analyser or ones that are common to all instruments are preferable. This study modelled how common QC targets influence assay error detection before examining their effect on real-world data.

METHODS

The effect of variable bias and imprecision on error detection and false rejection rates when using common or individual QC targets on two instruments was simulated. QC data from tests run on two identical Beckman instruments (6-month period, same QC lot, n > 100 points for each instrument) determined likely real-world consequences.

RESULTS

Compared to individual QC targets, common targets had an asymmetrical effect on systematic error detection, with one instrument assay losing detection power more than the other gained. If individual in-control assay standard deviations (SDs) differed, then common targets led to one assay failing QC more frequently. Applied to two analysers (95 QC levels and 45 tests), common targets reduced one instrument's error detection by ≥ 0.4 sigma on 15/45 (33%) of tests. Such targets also meant 14/45 (31%) of assays on one in-control instrument would fail over twice as frequently as the other (median ratio 1.62, IQR 1.20-2.39) using a 2SD rule.

CONCLUSIONS

Compared to instrument-specific QC targets, common targets can reduce the probability of detecting changes in individual assay performance and cause one in-control assay to fail QC more frequently than another. Any impact on clinical care requires further investigation.

The effectiveness of blood glucose and blood ketone measurement in identifying significant acidosis in diabetic ketoacidosis patients

BACKGROUND

Patients with diabetic ketoacidosis (DKA), a potentially fatal complication of type 1 diabetes, have hyperglycemia, ketonemia and metabolic acidosis. Blood glucose and blood ketone results are often used to triage patients with suspected DKA. This study aimed to establish how effective blood glucose and blood ketone (beta-hydroxybutyrate, BOHB) measurements are in identifying patients with significant acidosis and sought to validate existing diagnostic BOHB thresholds.

METHODS

Initial Emergency Department results on 161 presumptive DKA episodes in 95 patients (42 F, 53 M, age range 14-89 years) containing a complete dataset of D (glucose), K (BOHB) and A (Bicarbonate [HCO3] and pH) results.

RESULTS

Blood glucose correlated poorly with BOHB (r = 0.28 p = 0.0003), pH (r= -0.25, p = 0.002) and HCO3 (r= -0.17, p = 0.04). BOHB, though better, was still limited in predicting pH (r = -0.44, p < 0.0001) and HCO3 (r = -0.49, p < 0.0001). A HCO3 of 18mmol/L equated to a BOHB concentration of 4.3mmol/L, whilst a HCO3 of 15mmol/L equated to a BOHB of 4.7mmol/L. Of the 133 of 161 events with HCO3 < 18mmol/L, 22 were not hyperglycemic (> 13.9mmol/L, n = 8), ketonemic (≤ 3mmol/L, n = 9) or either (n = 5).

CONCLUSIONS

The commonly employed BOHB diagnostic cutoff of 3mmol/L could not be verified. Since acid-base status was poorly predicted by both glucose and BOHB, this highlights that, regardless of their results, pH and/or HCO3 should also be tested in any patient suspected of DKA.

Establishing Pragmatic Analytical Performance Specifications for Blood Beta-Hydroxybutyrate Testing

BACKGROUND

Currently, no authoritative guidelines exist recommending the analytical performance specification (APS) of blood beta-hydroxybutyrate (BOHB) testing in order to meet the clinical needs of patients. This study has applied existing diabetic ketoacidosis (DKA) BOHB diagnostic thresholds and the recommended rates of fall in BOHB concentrations during DKA treatment to establish pragmatic APSs for BOHB testing.

METHODS

Required analytical performance was based on 2 clinical requirements: (a) to reliably distinguish between non-adjacent DKA BOHB diagnostic categories of <0.6, 0.6 to 1.5, 1.6 to 2.9, and ≥3 mmol/L, and (b) to be assured that a measured 0.5 mmol/L reduction in BOHB indicates the true concentration is at least falling (meaning >0 mmol/L decline).

RESULTS

An analytical coefficient of variation (CV) of <21.5% could reliably distinguish all non-adjacent diagnostic categories with >99% certainty, assuming zero bias. In contrast, within-day CVs of 4.9%, 7.0%, and 9.1% at 3 mmol/L BOHB were required to assure truly falling ketone concentrations with 99% (optimal), 95% (desirable), and 90% (minimal) probability, respectively. These CVs are larger at lower BOHB concentrations and smaller at higher concentrations.

CONCLUSIONS

Reliable tracking of changes in BOHB during DKA treatment largely drives the requirement for analytical performance. These data can be used to guide minimal, desirable, and optimal performance targets for BOHB meters and laboratory assays.

Factors influencing the derivation and clinical application of blood calcium adjustment equations

BACKGROUND

Laboratories are recommended to use patient data to derive their local adjusted calcium (adjCa) equation, using numerous criteria to exclude patients with potential calcium metabolism abnormalities. It is not known which, if any, of the exclusions influence the final equation formula, or to what extent. This study investigated the effect using fewer exclusions has on adjCa equations and on patient results when compared to a reference equation.

METHODS

A reference ACB adjCa equation was derived from the total calcium and albumin pairs of 1305 individuals who, from an initial 22,906 adults, met recommended criteria (excluding abnormalities in either calcium, albumin, creatinine, magnesium, ALP or ALT, and specific clinical areas). This reference equation was compared to seven alternatives derived using fewer criteria, including one with no exclusions. All equations were applied to a validation cohort (n=19,640) to determine their effect on adjCa results and on categorizing patients into hypo-, normo- or hypercalcaemia.

RESULTS

Most alternative adjCa equations, including the one without any exclusions, showed no statistical (p < 0.05) difference in their slope or intercept compared to the ACB reference. Nor did any of the validation cohort have a clinically significantly different adjCa result (>5% and >0.1 mmol/L different) when applying an alternative rather than the reference equation. Additionally, no alternative equation changed the kappa categorization of the validation population's calcium status.

CONCLUSIONS

When deriving adjCa equations, most exclusion criteria have little influence on the equation or patient results, including using none at all. This knowledge could simplify deployment of local equations.

Progressive loss of corneal nerve fibers is associated with physical inactivity and glucose lowering medication associated with weight gain in type 2 diabetes

Aims/Introduction

Limited studies have identified risk factors linked to the progression of diabetic peripheral neuropathy (DPN) in type 2 diabetes. This study examined the association of risk factors with change in neuropathy measures over 2 years.

Materials and Methods

Participants with type 2 diabetes (n = 78) and controls (n = 26) underwent assessment of clinical and metabolic parameters and neuropathy using corneal confocal microscopy (CCM), vibration perception threshold (VPT), and the DN4 questionnaire at baseline and 2 year follow‐up.

Results

Participants with type 2 diabetes had a lower corneal nerve fiber density (CNFD), branch density (CNBD), and fiber length (CNFL) (P ≤ 0.0001) and a higher VPT (P ≤ 0.01) compared with controls. Over 2 years, despite a modest reduction in HbA1c (P ≤ 0.001), body weight (P ≤ 0.05), and LDL (P ≤ 0.05) the prevalence of DPN (P = 0.28) and painful DPN (P = 0.21) did not change, but there was a significant further reduction in CNBD (P ≤ 0.0001) and CNFL (P ≤ 0.05). CNFD, CNBD, and CNFL decreased significantly in physically inactive subjects (P < 0.05–0.0001), whilst there was no change in CNFD (P = 0.07) or CNFL (P = 0.85) in physically active subjects. Furthermore, there was no change in CNFD (P = 0.82), CNBD (P = 0.08), or CNFL (P = 0.66) in patients treated with glucose lowering medication associated with weight loss, whilst CNBD (P = 0.001) decreased in patients on glucose lowering medication associated with weight gain.

Conclusions

In participants with type 2 diabetes, despite a modest improvement in HbA1c, body weight, and LDL there was a progressive loss of corneal nerve fibers; except in those who were physically active or on glucose lowering medication associated with weight loss.

Efficacy and Safety of PCSK9 Monoclonal Antibodies in Patients With Diabetes

PURPOSE

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors are novel drugs that have proven efficacy in improving cardiovascular outcomes. Roles for the PCSK9 molecule in metabolic pathways beyond LDL receptor processing and cholesterol homeostasis are well established. PCSK9 genetic variants associated with lower LDL-C levels correlate with a higher incidence of type 2 diabetes (T2DM), calling into question the appropriateness of these drugs in patients with T2DM and those at high risk of developing diabetes, and whether cardiovascular benefit seen with PCSK9 inhibitors might be offset by resultant dysglycemia. The purpose of this review was to examine the role of PCSK9 protein in glucose homeostasis, the impact of PCSK9 inhibition in relation to glucose homeostasis, and whether some of the cardiovascular benefit seen with PCSK9 inhibitors and statins might be offset by resultant dysglycemia.

METHODS

Comprehensive literature searches of electronic databases of PubMed, EMBASE, and OVID were conducted by using the search terms hyperlipidaemia, PCSK9, diabetes, and glucose as well as other relevant papers of interest collected by the authors. The retrieved papers were reviewed and shortlisted most relevant ones.

FINDINGS

Genetically determined lower circulating LDL-C and PCSK9 concentrations may have an incremental effect in increasing T2DM incidence, but any perceived harm is outweighed by the reduced risk of atherosclerotic cardiovascular disease achieved through lower lifetime exposure to LDL-C. PCSK9 monoclonal antibodies are effective and safe in patients with T2DM and those at high risk of developing it. The number-needed-to-treat to prevent one atherosclerotic cardiovascular disease event in the FOURIER (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk) study in the subgroup with diabetes is significantly lower than for those without. Therefore, T2DM or being at high risk to develop it should not be a reason to avoid these agents. The safety of PCSK9 inhibition in relation to glucose homeostasis may depend on the method of inhibition and whether it occurs in circulation or the cells. Data from experimental studies and randomized controlled trials suggest no detrimental effect of PCSK9 monoclonal antibodies on glucose homeostasis. More data and large randomized controlled studies are needed to assess the impact of other methods of PCSK9 inhibition on glucose homeostasis.

IMPLICATIONS

PCSK9monoclonal antibodies markedly reduce LDL-C and consistently reduce cardiovascular mortality in patients with and without diabetes. Current evidence does not suggest an adverse effect of PCSK9 monoclonal antibodies on glycemic parameters.

Controversies Around the Measurement of Blood Ketones to Diagnose and Manage Diabetic Ketoacidosis

The measurement of blood ketones in preference to urine ketones has become a well-established tool in the diagnosis and management of diabetic ketoacidosis (DKA). However, there remains considerable disparity between diabetes guidelines regarding if, how, and when this test should be used. While recent guidelines now mainly emphasize blood measurement, several issues nonetheless remain. Many laboratories still measure blood ketones using a semiquantitative test that does not measure the predominant ketone, β-hydroxybutyrate (BOHB), which may hinder patient management. Even when BOHB is measured, the evidence for cutoffs used in DKA diagnosis or exclusion is limited, while its use in gauging severity, treatment progress, and resolution is not fully clear. Lastly, although employing point-of-care meters instead of a laboratory for BOHB measurement brings undoubted benefits, this approach has its own challenges. This article provides a perspective on these topics to complement current recommendations and to suggest how future research may improve its use in the DKA context.

The retinopathy-derived HbA1c threshold of 6.5% for type 2 diabetes also captures the risk of diabetic nephropathy in NHANES

AIM

To determine if an HbA1c diagnostic threshold of less than 6.5% (<48 mmol/mol) could be identified based on a urinary albumin-creatinine ratio (UACR) of 30 mg/g or higher in subjects not known to have diabetes.

METHODS

A UACR was measured for 20 158 participants in the 2011-2018 nationally representative cross-sectional National Health and Nutrition Examination Surveys (NHANES; cycles 7-10 inclusive).

RESULTS

There was a significant trend for an increasing risk with a UACR of 30 mg/g or higher across increasing HbA1c categories (P < .0001). This trend was mainly attributable to the high prevalence of raised UACR in the 7.0% or higher HbA1c subgroup of subjects not previously diagnosed with diabetes. None of the odds ratios in the lower HbA1c subgroups versus the HbA1c subgroup of less than 5.0% reached significance. There were racial/ethnic differences in UACR risk (P < .0001), with White and Black subjects exhibiting little increased risk (vs. HbA1c <5.0%) until they reached an HbA1c of 7.0%, while Asian and Hispanic subjects showed some increased, but non-significant, risks at lower HbA1c levels. Maximizing the area under receiver operating characteristic curves from logistic regressions predicted an ideal HbA1c threshold of 5.8%, but there was little variation in area from 5.5% to 7.0%.

CONCLUSION

A clinically useful diagnostic threshold below 6.5% for HbA1c for elevated UACR risk was not identified, with an increased risk only obvious at an HbA1c of 7.0% or higher. Thus, the retinopathy-derived HbA1c threshold of 6.5% also captures the risk of diabetic nephropathy in NHANES.

Reducing neonatal phlebotomy blood losses through the accurate calculation of minimum test volume requirements

BACKGROUND

Repeated phlebotomy for laboratory diagnostic testing is a known cause of iatrogenic anaemia and in critically ill neonates often leads to blood transfusion being required. This study has developed a spreadsheet clinical decision support tool to allow neonatal staff to determine the true minimum blood volume required to analyse groups of blood tests and modelled its potential benefit compared with the existing system in use.

METHODS

The tool calculates the minimum blood volume accounting for novel factors including the current patient haematocrit for plasma/serum samples, instrument minimum test and dead volumes (including those where shared) and sharing of samples within/between laboratory departments. A year of neonatal unit laboratory requests were examined comparing the volumes and containers of blood recommended by the hospital information system with both the amount actually collected by staff and that recommended by the tool.

RESULTS

A total of 463 patients had 8481 blood draws for 23,899 tests or test profiles over the year. The hospital information system recommended collecting 11,222 mL of blood into 18,509 containers, while 17,734 containers were actually received (10,717 mL if fully filled). The tool recommended collecting 4915 mL of blood into 15,549 containers.

CONCLUSIONS

This tool allows neonatal intensive care unit staff to objectively determine the minimum blood volume required for a combination of tests and is generalizable between laboratory instruments. Compared with the hospital information system, use of the minimum blood volume clinical decision support tool could maximally reduce the volume of blood collected from this neonatal unit by more than a half. Neonatal intensive care unit staff had apparently already gone some way to determining their own minimum volumes required.

Diagnosing type 2 diabetes using Hemoglobin A1c: a systematic review and meta-analysis of the diagnostic cutpoint based on microvascular complications

AIMS

Diabetic microvascular complications of retinopathy, nephropathy and neuropathy may occur at hemoglobin A1c levels (HbA1c) below the 6.5% (48 mmol/mol) diagnostic threshold. Our objective was to assess the validity of the HbA1c diagnostic cutpoint of 6.5% based upon published evidence of the prevalence of retinopathy, nephropathy and neuropathy as markers of diabetes.

METHODS

Data Sources PubMed, Embase, Cochrane, Scopus and CINAHL from 1990-March 2019, grey literature sources. Study Selection All studies reported after 1990 (to ensure standardized HbA1c values) where HbA1c levels were presented in relation to prevalence of retinopathy, nephropathy or neuropathy in subjects not known to have diabetes. Data Extraction Studies were screened independently, data abstracted, and risk of bias appraised. Data Synthesis Data were synthesized using HbA1c categories of < 6.0% (< 42 mmol/mol), 6.0-6.4% (42-47 mmol/mol) and ≥ 6.5% (≥ 48 mmol/mol). Random-effects meta-analyses were conducted for retinopathy, nephropathy and neuropathy prevalence stratified by HbA1c categories. Random-effects multivariable meta-regression was conducted to identify predictors of retinopathy prevalence and sources of between-study heterogeneity.

RESULTS

Pooled mean prevalence was: 4.0%(95% CI: 3.2-5.0%) for retinopathy, 10.5% (95% CI: 4.0-19.5%) for nephropathy, 2.5% (95% CI: 1.1-4.3%) for neuropathy. Mean prevalence when stratified for HbA1c < 6.0%, 6.0-6.4% and ≥ 6.5% was: retinopathy: 3.4% (95% CI: 1.8-5.4%), 2.3% (95% CI: 1.6-3.2%) and 7.8%(95% CI: 5.7-10.3%); nephropathy: 7.1% (95% CI: 1.7-15.9%), 9.6% (95% CI: 0.8-26.4%) and 17.1% (95% CI: 1.0-46.9%); neuropathy: 2.1% (95% CI: 0.0-6.8%), 3.4% (95% CI: 0.0-11.6%) and 2.8% (95% CI: 0.0-12.8%). Multivariable meta-regression showed HbA1c ≥ 6.5% (OR: 4.05; 95% CI: 1.92-8.57%), age > 55 (OR: 3.23; 95% CI 1.81-5.77), and African-American race (OR: 10.73; 95% CI: 4.34-26.55), to be associated with higher retinopathy prevalence. Marked heterogeneity in prevalence estimates was found across all meta-analyses (Cochran's Q-statistic p < 0.0001).

CONCLUSIONS

The prevalence of nephropathy and moderate retinopathy was increased in subjects with HbA1c values ≥ 6.5% confirming the high specificity of this value for diagnosing T2DM; however, at HbA1c < 6.5% retinopathy increased at age > 55 years and, most strikingly, in African-Americans, suggesting there may be excess microvascular complication prevalence (particularly nephropathy) in individuals below the diabetes diagnostic threshold.

Using clinical guidelines to assess the potential value of laboratory medicine in clinical decision-making

Introduction

It is often quoted that 70% of clinical decisions are based on laboratory results, but the evidence to substantiate this claim is lacking. Since clinical guidelines aim to document best-practice decision making for specific disease conditions, inclusion of any laboratory test means that the best available evidence is recommending clinicians use it. Cardiovascular disease (CVD) is the world’s most common cause of mortality, so this study reviewed all CVD guidelines published by five national/international authorities to determine what proportion of them recommended laboratory testing.

Materials and methods

Five leading CVD guidelines were examined, namely the European Society of Cardiology (ESC), the UK National Institute for Health and Clinical Excellence (NICE), the American College of Cardiology (ACC), the Australian Heart Foundation (AHF) and the Cardiac Society of Australia and New Zealand (CSANZ).

Results

A total of 101 guidelines were reviewed. Of the 33 individual ESC guidelines relating to CVD, 24/33 made a direct reference to the use of clinical laboratory tests in either diagnosis or follow-up treatment. The same applied to 15/20 of NICE guidelines, 24/32 from the ACC and 15/16 from the AHF/CSANZ. Renal function and blood count testing were the most recommended (39 and 26 times), with lipid, troponin and natriuretic peptide measurement advocated 25, 19 and 19 times respectively.

Conclusions

This study has shown that laboratory testing is advocated by between 73% and 94% of individual CVD guideline recommendations from five national/international authorities. This provides an index to assess the potential value of laboratory medicine to healthcare.

The effects of empagliflozin vs metformin on endothelial microparticles in overweight/obese women with polycystic ovary syndrome

CONTEXT

Endothelial microparticles (EMPs) are novel, surrogate biomarkers of endothelial function and have been shown to be elevated in women with polycystic ovary syndrome (PCOS). It remains poorly understood how pharmacological options for managing PCOS affect EMP levels.

OBJECTIVE

To characterise and compare the effects of empagliflozin vs metformin on the circulating levels of EMPs in overweight/obese women with PCOS.

METHODS

This was a randomised, comparative, 12-week single-centre trial conducted at the Academic Diabetes, Endocrinology and Metabolism Research Centre, Hull, UK. This analysis includes data from 39 overweight/obese women with PCOS who completed the study and were randomised to empagliflozin (15 mg/day) (n = 19) or metformin (1500 mg/day) (n = 20). Blood samples were collected at baseline and 12 weeks after treatment and analysed for specific surface proteins (ICAM-1, VCAM-1, PECAM-1, E-selectin and endoglin) expressed by circulating EMPs using flow cytometry.

RESULTS

In the empagliflozin group, ICAM-1 (P = 0.006), E-selectin (P = 0.016) and VCAM-1 (P = 0.001) EMPs increased significantly following 12 weeks of treatment, but no changes were seen in PECAM-1 (P = 0.93) or endoglin (P = 0.13) EMPs. In the metformin group, VCAM-1 EMPs (P < 0.001) increased significantly after 12 weeks of treatment, whereas all other EMPs remained unchanged. When data were expressed as percentage change from baseline in each group, no significant differences were seen between groups for any biomarker (P-values from 0.22 to 0.80).

CONCLUSIONS

Short-term administration of empagliflozin and metformin in overweight/obese women with PCOS appear to increase EMPs expressed by endothelial cells during their activation.

Quality control failures exceeding the weekly limit (QC FEWL): a simple tool to improve assay error detection

Background

Even when a laboratory analyte testing process is in control, routine quality control testing will fail with a frequency that can be predicted by the number of quality control levels used, the run frequency and the control rule employed. We explored whether simply counting the number of assay quality control run failures during a running week, and then objectively determining if there was an excess, could complement daily quality control processes in identifying an out-of-control assay.

Methods

Binomial statistics were used to determine the threshold number of quality control run failures in any rolling week which would statistically exceed that expected for a particular test. Power function graphs were used to establish error detection (Ped) and false rejection rates compared with popular control rules.

Results

Identifying quality control failures exceeding the weekly limit (QC FEWL) is a more powerful means of detecting smaller systematic (bias) errors than traditional daily control rules (12s, 13s or 13s/22s/R4s) and markedly superior in detecting smaller random (imprecision) errors while maintaining false identification rates below 2%. Error detection rates also exceeded those using a within- and between-run Westgard multirule (13s/22s/41s/10x).

Conclusions

Daily review of tests shown to statistically exceed their rolling week limit of expected quality control run failures is more powerful than traditional quality control tools at identifying potential systematic and random test errors and so offers a supplement to daily quality control practices that has no requirement for complex data extraction or manipulation.

Effects of empagliflozin on metabolic parameters in polycystic ovary syndrome: A randomized controlled study

BACKGROUND

Empagliflozin is a sodium-glucose-cotransporter-2 inhibitor that improves cardiovascular risk and promotes weight loss in patients with type-2 diabetes. Polycystic ovary syndrome (PCOS) is associated with obesity and increased cardiovascular risk; therefore, empagliflozin may be of benefit for these women. The aim of this study was to compare the effects of empagliflozin vs metformin on anthropometric and body composition, hormonal and metabolic parameters in women with PCOS.

MATERIALS AND METHODS

A randomized open-label study was conducted in women with PCOS who were randomized to either empagliflozin 25 mg (n = 19) or metformin 1500 mg (n = 20) daily for 12 weeks. The main outcomes assessed were changes in anthropometric and body composition, hormonal and metabolic parameters.

RESULTS

Univariate analysis showed significant differences in weight (empagliflozin: -1.4 ± 3.2% vs metformin: 1.2 ± 2.3%; P = 0.006), body mass index (empagliflozin: -1.4 ± 3.2% vs metformin: 1.1 ± 2.2%; P = 0.006), waist circumference (empagliflozin: -1.6 ± 2.8% vs metformin: 0.2 ± 2.1%; P = 0.029) and hip circumference (empagliflozin: -2.0 ± 3.0% vs metformin: 1.1 ± 1.9%; P = 0.001), basal metabolic rate (empagliflozin: -1.8 ± 2.9% vs metformin: 0.1 ± 1.9%, P = 0.024) and fat mass (empagliflozin: -0.7 ± 4.9% vs metformin, 3.2 ± 5.0%; P = 0.023) between the empagliflozin and the metformin groups. These differences were confirmed in linear regression analysis after adjustment for relevant covariates. There were no significant changes in hormonal or metabolic parameters between both groups.

CONCLUSION

There was a significant improvement in anthropometric parameters and body composition, in overweight and obese women with PCOS after 12 weeks of treatment with empagliflozin compared to metformin, although no changes were seen in hormonal or metabolic parameters.

Environmental effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes mellitus

OBJECTIVE

This study aimed to explore the effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes.

MATERIALS AND METHODS

A three-way, cross-over, randomised study was performed in adults with type 1 diabetes mellitus (n = 10). The pharmacodynamics profile of a single dose of short-acting insulin (insulin lispro) was investigated, using a controlled environmental chamber, under three environmental conditions: (a) temperature: 15°C and humidity: 10%; (b) temperature: 30°C and humidity: 10%; and (c) temperature: 30°C and humidity: 60%. A euglycaemic glucose clamp technique ensured constant blood glucose of 100 mg/dL (5.5 mmol/L). The following pharmacodynamic endpoints were calculated: maximum glucose infusion rate (GIR_max ), time to GIR_max (t_GIRmax ), total area under the curve (AUC) for GIR from 0-6 hours (AUC_GIR.0-6h ), and partial AUCs (AUC_GIR.0-1h , AUC_GIR.0-2h and AUC_GIR.2-6h ).

RESULTS

Higher temperature (30°C) under 10% fixed humidity conditions resulted in greater GIR_max (P = 0.04) and a later t_GIR.max (P = 0.049) compared to lower temperature (15°C). Humidity did not affect any pharmacodynamic parameter. When the combined effects of temperature and humidity were explored, t_GIR.max (P = 0.008) occurred earlier, with a lower late insulin pharmacodynamic effect (AUC_GIR.2-6h ; P = 0.017) at a temperature of 15°C and humidity of 10% compared to a temperature of 30°C and humidity of 60%.

CONCLUSIONS

High ambient temperature resulted in a greater insulin peak effect compared to low ambient temperature, with the contribution of high relative humidity apparent only at high ambient temperature. This suggests that patients with type 1 diabetes mellitus who are entering higher environmental temperatures, with or without high humidity, could experience more hypoglycaemic events.

Effects of acute insulin-induced hypoglycaemia on endothelial microparticles in adults with and without type 2 diabetes

AIMS

To assess whether endothelial microparticles (EMPs), novel surrogate markers of endothelial injury and dysfunction, are differentially produced in response to acute insulin-induced hypoglycaemia in adults with and without type 2 diabetes.

MATERIALS AND METHODS

A prospective, parallel study was conducted in individuals with type 2 diabetes (n = 23) and controls (n = 22). Hypoglycaemia (<2.2 mmoL/L: <40 mg/dL) was achieved by intravenous infusion of soluble insulin. Blood samples were collected at baseline and at 0, 30, 60, 120, 240 minutes and 24 hours after hypoglycaemia and analysed for CD31⁺ (platelet endothelial cell adhesion molecule-1), CD54⁺ (intercellular adhesion molecule 1), CD62-E⁺ (E-selectin), CD105⁺ (endoglin), CD106⁺ (vascular cell adhesion molecule 1) and CD142⁺ (tissue factor) EMPs by flow cytometry. The peak elevations (% rise from 0 minutes after hypoglycaemia) in EMP within 240 minutes after insulin-induced hypoglycaemia were modelled using a regression model, with adjustment for relevant covariates. All EMPs were expressed as percentage from 0 minutes hypoglycaemia for each time point and total areas under the curve (AUC_0min-24h ) were calculated.

RESULTS

Following insulin-induced hypoglycaemia, levels of circulating EMPs were maximal at 240 minutes (P < 0.001) and returned to baseline values within 24 hours for both groups. The peak elevations (% rise from 0 minutes following hypoglycaemia) seen in CD31⁺ , CD54⁺ , CD62-E⁺ , CD105⁺ and CD142⁺ EMPs within 240 minutes were associated with diabetes status after adjustments for all relevant covariates. Individuals with type 2 diabetes showed increased CD31⁺ EMPs AUC_0min-24h (P = 0.014) and CD105⁺ EMPs AUC_0min-24h (P = 0.006) compared with controls, but there were no differences for CD54⁺ (P = 0.91), CD62-E⁺ (P = 0.14), CD106⁺ (P = 0.36) or CD142⁺ (P = 0.77) EMPs AUC_0min-24h .

CONCLUSIONS

The associations between peak elevations within 240 minutes after insulin-induced hypoglycaemia for CD31⁺ , CD54⁺ , CD62-E⁺ , CD105⁺ and CD142⁺ and diabetes status indicate that the assessment of a panel of EMPs within this timeframe would identify a hypoglycaemic event in this population. The greater overall responses over time (AUCs) for apoptosis-induced CD31⁺ and CD105⁺ EMPs suggest that hypoglycaemia exerts greater endothelial stress in type 2 diabetes.

A survey of clinical laboratory instrument verification in the UK and New Zealand

Background

Clinical laboratory instrument verification testing is often an accreditation requirement. However, it is not known what verification procedures are in routine use or how often the process identifies problems which need addressing prior to testing clinical samples.

Objective

To investigate which standards are currently being used for laboratory verification in UK and New Zealand (NZ) clinical laboratories and to help establish if the activity justifies the effort required.

Methods

A survey of verification of clinical laboratory instrumentation was distributed to members of the Association for Clinical Biochemistry and Laboratory Medicine and New Zealand Institute of Medical Laboratory Scientists. The survey consisted of questions on the verification elements used and whether acceptance criteria were met.

Results

Nineteen of 72 (26%) of responders only used organization-developed protocols for verification, 20/72 (28%) solely used national/international guidelines, while 16/72 (22%) used a combination. Manufacturers’ claims were partly or entirely used as acceptance criteria for imprecision (89%), accuracy (64%) and analytical measuring range (94%), with these being met on 61%, 67% and 93% of occasions, respectively. For patient comparison and linearity, acceptance criteria were met by 71% and 91%. Only 27–36% undertook any troubleshooting before accepting a failed component of verification.

Conclusions

Laboratories in the UK and NZ are currently using a variety of verification standards and acceptance criteria for instrument verification. It is common for instruments to fail, especially following the assessment of imprecision and accuracy. While this suggests the process is warranted, only a minority address failed elements before accepting verification.

A Randomized, Controlled Trial of Vitamin D Supplementation on Cardiovascular Risk Factors, Hormones, and Liver Markers in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) increases the risk of metabolic syndrome and non-alcoholic-fatty-liver disease (NAFLD). Vitamin D supplementation may exert positive effects on liver biochemistry in patients with NAFLD; however, its effects on PCOS are unknown. This randomized, double-blind, placebo-controlled study explored the effect of vitamin D supplementation on cardiovascular risk factors (high-sensitivity C-reactive protein (hs-CRP), weight, body mass index (BMI), lipid profile, glucose levels, insulin levels, the homeostatic model assessment-insulin resistance (HOMA-IR), hormones (free androgen index (FAI), testosterone, sex hormone binding globulin (SHBG), and liver markers (alanine aminotransferase (ALT), hyaluronic acid (HA), N-terminal pro-peptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases-1 (TIMP-1), and the enhanced liver fibrosis (ELF) score). Forty women with PCOS were recruited and randomized to vitamin D (3200 IU) or placebo daily for 3 months. All outcomes were measured at baseline and 3 months follow-up (FU). Greater increases in vitamin D levels were shown in the supplementation group (vitamin D, baseline: 25.6 ± 11.4 nmol/L, FU: 90.4 ± 19.5 nmol/L vs. placebo, baseline: 30.9 ± 11.1 nmol/L, FU: 47.6 ± 20.5 nmol/L, p < 0.001). Between groups comparisons (% baseline change) revealed significant differences in ALT (p = 0.042) and a weak effect indicating a greater reduction in the HOMA-IR in the vitamin D group (p = 0.051). No further between group differences were seen in other cardiovascular risk factor, liver markers, or hormones. This study supports beneficial effects of vitamin D supplementation on liver markers and modest improvements in insulin sensitivity in vitamin D deficient women with PCOS.

The Effect of Exenatide on Cardiovascular Risk Markers in Women With Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is associated with an adverse cardiovascular risk profile including a prothrombotic state. Exenatide has been shown to be effective at improving insulin sensitivity and weight loss in PCOS; therefore this study was undertaken to assess its effects on weight, endothelial function, inflammatory markers, and fibrin structure/function in overweight/obese women with PCOS. Methods: Thirty overweight/obese anovulatory women with all 3 Rotterdam criteria received exenatide 5 mcg bd for 4 weeks then 10 mcg bd for 12 weeks. The primary outcome was change in weight; secondary outcomes were changes in endothelial function [Reactive Hyperemia-Peripheral Arterial Tonometry (RH-PAT)], serum endothelial markers (ICAM-1, VCAM-1, E-selectin, and P-selectin), change in inflammation (hsCRP), and alteration in clot structure and function [maximum absorbance (MA), and time from full clot formation to 50% lysis (LT)]. Results: Twenty patients completed the study. Exenatide reduced weight 111.8 ± 4.8 to 108.6 ± 4.6 kg p = 0.003. Serum endothelial markers changed with a reduction in ICAM-1 (247.2 ± 12.9 to 231.3 ± 11.5 ng/ml p = 0.02), p-selectin (101.1 ± 8.2 to 87.4 ± 6.6 ng/ml p = 0.01), and e-selectin (38.5 ± 3.3 to 33.6 ± 2.6 ng/ml p = 0.03), without an overt change in endothelial function. Inflammation improved (CRP; 8.5 ± 1.4 to 5.6 ± 0.8 mmol/L p = 0.001), there was a reduction in clot function (LT; 2,987 ± 494 to 1,926 ± 321 s p = 0.02) but not clot structure. Conclusion: Exenatide caused a 3% reduction in weight, improved serum markers of endothelial function, inflammation, and clot function reflecting an improvement in cardiovascular risk indices in these women with PCOS. This suggests exenatide could be an effective treatment for obese women with PCOS. Clinical Trial Registration: ISRCTN81902209.

The Effects of Soy Protein and Cocoa With or Without Isoflavones on Glycemic Control in Type 2 Diabetes. A Double-Blind, Randomized, Placebo-Controlled Study

Objective: Soy and cocoa have been suggested to be beneficial for diabetes. The aim of this study was to identify the effects of soy protein, isoflavones, and cocoa on glycemic control parameters. Research design and methods: The study was a parallel, double-blind, placebo-controlled study where patients with diet or metformin controlled type 2 diabetes were randomized to, casein soy protein with or without isoflavones (SPI, SP), and with or without cocoa (SPIC, SPC) arms for an 8 week period. Glycemic control and cardiovascular risk factors were assessed prior to and after the completion of the dietary intervention. Sixty participants completed the study. Results: Soy protein improved HbA1c compared to casein (p < 0.05). The addition of isoflavones improved indices of insulin resistance and LDL [delta QUICKIE (SPI: -0.12 ± 0.04 vs. SP: 0.03 ± 0.06, p = 0.03); delta LDL (-0.27 ± 0.41 vs. 0.22 ± 0.43, p = 0.02); percentage change in HOMA (31.02 ± 54.75 vs. -14.42 ± 27.07, p = 0.02); percentage change in QUICKIE (-3.89 ± 7.07 vs. 6.11 ± 10.54, p = 0.01)]. However, the addition of cocoa provided no benefit with or without isoflavones. Summary: Soy protein had intrinsic activity on glycemic control compared to casein. Isoflavones improved both insulin resistance and LDL, but cocoa did not have added benefit on these indices. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01754662.

Development of a novel risk prediction and risk stratification score for polycystic ovary syndrome

OBJECTIVE

The aim of this study was to develop a simple phenotypic algorithm that can capture the underlying clinical and hormonal abnormalities to help in the diagnosis and risk stratification of polycystic ovary syndrome (PCOS).

METHODS

The study consisted of 111 women with PCOS fulfilling the Rotterdam diagnostic criteria and 67 women without PCOS. A Firth's penalized logistic regression model was used for independent variable section. Model optimism, discrimination and calibration were assessed using bootstrapping, area under the curve (AUC) and Hosmer-Lemeshow statistics, respectively. The prognostic index (PI) and risk score for developing PCOS were calculated using independent variables from the regression model.

RESULTS

Firth penalized logistic regression model with backward selection identified four independent predictors of PCOS namely free androgen index [β 0.30 (0.12), P = 0.008], 17-OHP [β = 0.20 (0.01), P = 0.026], anti-mullerian hormone [AMH; β = 0.04 (0.01) P < 0.0001] and waist circumference [β = 0.08 (0.02), P < 0.0001]. The model estimates indicated high internal validity (minimal optimism on 1000-fold bootstrapping), good discrimination ability (bias corrected c-statistic = 0.90) and good calibration (Hosmer-Lemeshow χ²  = 3.7865). PCOS women with a high-risk score (q1 + q2 + q3 vs q4) presented with a worse metabolic profile characterized by a higher 2-hour glucose (P = 0.01), insulin (P = 0.0003), triglycerides (P = 0.0005), C-reactive protein (P < 0.0001) and low HDL-cholesterol (P = 0.02) as compared to those with lower risk score for PCOS.

CONCLUSIONS

We propose a simple four-variable model, which captures the underlying clinical and hormonal abnormalities in PCOS and can be used for diagnosis and metabolic risk stratification in women with PCOS.

An overview of EFLM harmonization activities in Europe

The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has initiated many harmonization activities in all phases of the examination process. The EFLM is dealing with both the scientific and the educational aspects of harmonization, with the intention of disseminating best practice in laboratory medicine throughout Europe. Priorities have been given (1) to establish a standard for conducting and assessing biological variation studies and to construct an evidence based EFLM webpage on biological variation data, (2) to harmonize preanalytical procedures by producing European guidelines, (3) to improve test ordering and interpretation, (4) to produce other common European guidelines for laboratory medicine and play an active part in development of clinical guidelines, (5) to establish a common basis for communicating laboratory results to patients, (6) to harmonize units of measurement throughout Europe, (7) to harmonize preanalytical procedures in molecular diagnostics and (8) to harmonize and optimize test evaluation procedures. The EFLM is also now launching the 5th version of the European Syllabus to help the education of European Specialists in Laboratory Medicine (EuSpLM), which is being supported by the development of e-learning courses. A register of EuSpLM is already established for members of National Societies in EU countries, and a similar register will be established for specialists in non-EU countries.

Soy isoflavones improve cardiovascular disease risk markers in women during the early menopause

BACKGROUND

Hormone replacement therapy may be beneficial for cardiovascular disease risk (CVR) in post-menopausal women. Soy isoflavones may act as selective estrogen receptor modulators. The aim of this study was to evaluate whether soy isoflavones had an effect on CVR markers.

METHODS

The expected 10-year risk of cardiovascular disease and mortality were calculated as a secondary endpoint from a double blind randomised parallel study involving 200 women (mean age 55 years, Caucasian, Hull, UK, 2012) in the early menopause who were randomised to 15 g soy protein with 66 mg isoflavone (SPI) or 15 g soy protein alone (depleted of all isoflavones; SP) given as a snack bar between meals daily for 6 months. Age, diabetes, smoking, blood pressure and lipid profiles were used to calculate CVR using the Framingham CVR engine.

RESULTS

SPI treatment resulted in a significant reduction in the metabolic parameters and systolic blood pressure compared to SP (p < 0.01). There were no changes in fasting lipid profile and diastolic blood pressure with either treatment. At 6 months, changes in these parameters with SPI treatment were reflected in a calculated 27% (p < 0.01) reduction in 10 year coronary heart disease risk, a 37% (p < 0.01) reduction in myocardial infarction risk, a 24% (p < 0.04) reduction in cardiovascular disease and 42% (p < 0.02) reduction in cardiovascular disease death risk.

CONCLUSIONS

Supplementation with soy protein with isoflavones for 6 months significantly improved CVR markers and calculated CVR at 6 months during early menopause compared to soy protein without isoflavones.

ISRCTN REGISTRY

ISRCTN34051237.

Anti-Müllerian hormone measurement for the diagnosis of polycystic ovary syndrome

OBJECTIVE

Anti-Müllerian hormone (AMH) is derived from the small antral follicles, and an elevated level has been suggested to add value to the Rotterdam criteria for the diagnosis of PCOS in cases of diagnostic uncertainty. Therefore, the role of AMH in the classical phenotype of PCOS was defined within a Caucasian population.

DESIGN

This was a cross-sectional study.

PATIENTS

Sixty Five women without PCOS and 110 women with PCOS fulfilling all 3 diagnostic Rotterdam criteria.

MEASUREMENTS

The main outcomes were the utility of serum AMH for the diagnosis of PCOS and its relationship to the metabolic parameters.

RESULTS

Anti-Müllerian hormone was increased in PCOS compared to controls (P < .001). Areas under the receiver operator curve showed AMH to be predictive of PCOS (0.76) using a cut-off AMH of 46 pmol/L, which is derived from the 95^th percentile of the controls that gave a 41% sensitivity and 86% specificity; an AMH cut-off of 35 pmol/L gave a 55% sensitivity and 79% specificity. Age- and BMI-adjusted multiple logistic regression showed that AMH was more predictive of PCOS independently of either serum testosterone (T) (OR = 4.04; 95% CI 1.42-11.11; P = .007) or free androgen index (FAI) (OR = 3.90; 95% CI 1.40-10.83; P = .009).

CONCLUSION

Whilst an elevated AMH has poor sensitivity, it is fourfold more likely to be associated with a diagnosis of PCOS, and supplementary to biochemical parameters will make a positive diagnosis of PCOS in 22% of patients when neither serum testosterone nor FAI is elevated.

The Effect of Phytoestrogen on Thyroid in Subclinical Hypothyroidism: Randomized, Double Blind, Crossover Study

Objective: Soy phytoestrogens are suggested to impair thyroid function but the effects of pharmacological doses of soy phytoestrogens are unknown; therefore, this study was performed to determine the effect of high dose soy phytoestrogens (66 mg) on thyroid function in subclinical hypothyroidism. Design and setting: Randomized, double-blind, crossover study. Participants: Forty four patients with subclinical hypothyroidism. Intervention: Participants were randomly allocated to either 66 mg phytoestrogen with 30 g soy protein (active) or 0 mg phytoestrogen with 30 g soy protein (placebo) supplementation for 8 weeks, washed out for 8 weeks and then crossed over for another 8 week period. Main outcome measures: The primary outcome was progression to overt hypothyroidism with the secondary outcome measures were changes in thyroid function tests. Results: Two patients in this trial progressed into overt hypothyroidism after high dose phytoestrogen supplementation. TSH, free thyroxine and triiodothyronine did not differ between groups. Conclusion: A pharmacological dose of 66 mg of soy phytoestrogens did not increase the overt thyroid failure rate or alter thyroid function tests in patients with subclinical hypothyroidism.

The Effect of High Dose Isoflavone Supplementation on Serum Reverse T3 in Euthyroid Men With Type 2 Diabetes and Post-menopausal Women

Background: The health benefits of soy are widely reported but there are queries on the effect of soy isoflavones on thyroid function and the underlying mechanism of action. Materials and Methods: We examined the effect of soy isoflavones on reverse tri-iodothyronine (or 3,3',5'-tri-iodothyronine; rT₃) in two studies comprising 400 patients: 200 men (study 1; 3 months) and 200 post-menopausal women (study 2; 6 months) who were randomized to consume 15 g soy protein with 66 mg of isoflavones (SPI) daily, or 15 g soy protein alone without isoflavones (SP) daily. Results: SPI supplementation increased rT₃ serum concentration in both men 0.41 (0.12) vs. 0.45 (0.14) nmol/L and women 0.33 (0.12) vs. 0.37 (0.09) nmol/L at 3 months compared to SP that was not seen at 6 months. Thyroid stimulating hormone (TSH) serum concentrations increased while free thyroxine (fT₄) concentrations decreased with 3 months of SPI compared to SP supplementation for both men and women. rT₃ correlated with TSH in both studies (p = 0.03) but not with either fT₃ or fT₄. fT₃ levels did not differ between the SPI and SP preparations. Conclusion: Soy isoflavones transiently increased rT3 levels within 3 months though reverted to baseline at 6 months. The mechanism for this would be either rT3 degrading deiodinase 1 and/or deiodinase 2 activities are transiently inhibited at 3 months, or inhibition of deiodinase 3, which generates rT3 from T4 is induced at 6 months. These changes were mirrored in the TSH concentrations, suggesting that short-term high dose isoflavone transiently impairs thyroid function in the first 3 months and may impact on general health during this period. ISRCTN Registry: ISRCTN 90604927; ISRCTN34051237.

Dynamic Change in Insulin Resistance Induced by Free Fatty Acids Is Unchanged Though Insulin Sensitivity Improves Following Endurance Exercise in PCOS

Background: Insulin resistance (IR) is the hallmark of PCOS and it is known that exercise may decrease it. What is unknown is whether exercise may mechanistically alter the underlying IR, attenuating the dynamic lipid induced IR in insulin resistant subjects. Methods: 12 women with polycystic ovary syndrome (PCOS) and 10 age and body mass index matched controls completed an 8 week supervised exercise program at 60% maximal oxygen consumption. Before and after the exercise program, all participants underwent hyperinsulinaemic euglycaemic clamps with either saline or intralipid infusions. Skewed data were log transformed and expressed as mean ± SEM. Results: Before exercise, women with PCOS had a higher HOMA-IR and lower VO₂ max than controls. Compared to saline, lipid infusion lowered the rate of insulin stimulated glucose disposal (M value; mg/kg/min) by 67 ± 5% (from 0.5 ± 0.03 to -0.25 ± 0.2, p = 0.01) in PCOS, and by 49 ± 7% (from 0.65 ± 0.06 to 0.3 ± 0.1, p = 0.01) in controls. The M value was significantly less in PCOS compared to controls for both saline (p < 0.01) and lipid (p < 0.05). Endurance exercise in PCOS improved VO₂ max and HOMA-IR, but not weight, to those of pre-exercise control subjects. The glucose disposal rate during the lipid infusion was reduced following exercise in PCOS, indicating decreased IR (67 ± 5 vs. 50 ± 7%, p = 0.02), but IR was not altered in controls (49 ± 7 vs. 45 ± 6%, p = 0.58). The incrementally increased IR induced by the lipid infusion did not differ between controls and PCOS. Conclusion: Insulin sensitivity improved with exercise in the PCOS group alone showing that IR can be modified, though likely transiently. However, the maximal IR response to the lipid infusion did not differ within and between control and PCOS subjects, indicating that the fundamental mechanism underlying insulin resistance was unchanged with exercise. Precis: Maximal insulin resistance induced by lipid infusion determined at baseline and 8 weeks after exercise in control and PCOS women did not differ, though insulin sensitivity increased in PCOS after exercise.

The effect of atorvastatin on pancreatic beta cell requirement in women with polycystic ovary syndrome

BACKGROUND

There is an increased risk of developing T2DM in women with polycystic ovary syndrome (PCOS), and there is evidence that statins improve metabolic parameters in these patients. However, there are some data to show that statins increase the risk of incipient diabetes.

MATERIALS AND METHODS

We have previously shown that 12 weeks of atorvastatin improves insulin resistance when measured using HOMA-IR. This post hoc analysis was designed to look at the effect of atorvastatin on pancreatic β cell function using HOMA-β in the same study. In this randomised, double-blind placebo controlled study, 40 medication-naïve patients with PCOS were randomised to either atorvastatin 20 mg daily or placebo for 3 months. A 3-month extension study for both groups of patients was undertaken with metformin 1500 mg daily after completing initial 3 months of atorvastatin or placebo.

RESULTS

There was a significant reduction in HOMA-β (240 ± 3.2 vs 177 ± 2.3; P value <0.01) after 12 weeks of atorvastatin treatment, which was maintained by metformin in the subsequent 12 weeks. There were no changes in HOMA-β after the placebo or after subsequent metformin treatment.There was no linear correlation between reduction in HOMA-β with improvement of free androgen index (FAI) (r² = 0.02; P = 0.72), testosterone (r² = 0.13; P = 0.49), SHBG (r² = 0.22; P = 0.48), hsCRP (r² = 0.19; P = 0.64), triglycerides (r² = 0.09; P = 0.12), total cholesterol (r² = 0.11; P = 0.32) or LDL-C (r² = 0.19; P = 0.38).

CONCLUSION

Treatment with atorvastatin for 12 weeks in women with PCOS significantly reduced HOMA-β. This could be potentially due to fall in β-cell requirement with improvement of insulin resistance rather than a reduction of β-cell function.

The prevalence and metabolic characteristics of polycystic ovary syndrome in the Qatari population

OBJECTIVE

The prevalence of polycystic ovary syndrome (PCOS) in the Qatari population is unknown and hence the estimated impact on the local population cannot be determined. The purpose of this study was to estimate the prevalence and metabolic features of PCOS among Qatari women.

DESIGN

Cross sectional analysis.

PATIENTS

3,017 Qatari subjects volunteered to be phenotyped and genotyped for the Qatar Biobank from which all women between the ages of 18-40 years were identified (750).

MEASUREMENTS

720 women had testosterone and sex hormone binding globulin (SHBG) measurements. PCOS was diagnosed according the National Institute of Health (NIH) Guidelines of a raised androgen level (free androgen index >4.5 or a raised total testosterone) and menstrual irregularity after the exclusion of other conditions.

RESULTS

All results are reported as mean value of PCOS versus control. 87 of 720 women fulfilled the NIH guidelines (12.1%) for PCOS specifically using a free androgen index greater than 4.5 or a total testosterone greater than 2.7nmol/l and menstrual irregularity. Subjects were heavier with a more metabolic profile of a greater systolic and diastolic blood pressure, higher levels of C reactive protein, insulin (p<0.01) and HbA1c (P<0.02), and decreased HDL levels (p<0.01). Pulse wave velocity as a marker of arterial stiffness was also increased (p<0.05).

CONCLUSIONS

By NIH guidelines the prevalence of PCOS in this Qatari cohort was 12.1% that would likely reflect 20% by Rotterdam criteria, with a markedly more metabolic phenotype than Qatari controls.

Endocannabinoid receptor blockade reduces alanine aminotransferase in polycystic ovary syndrome independent of weight loss

BACKGROUND

Evidence suggests that endocannabinoid system activation through the cannabinoid receptor 1 (CB1) is associated with enhanced liver injury, and CB1 antagonism may be beneficial. The aim of this study was to determine the impact of rimonabant (CB1 antagonist) on alanine aminotransferase (ALT), a hepatocellular injury marker, and a hepatic inflammatory cytokine profile.

METHODS

Post hoc review of 2 studies involving 50 obese women with PCOS and well matched for weight, randomised to weight reducing therapy; rimonabant (20 mg od) or orlistat (120 mg tds), or to insulin sensitising therapy metformin, (500 mg tds), or pioglitazone (45 mg od). No subject had non-alcoholic fatty liver disease (NAFLD).

RESULTS

Treatment with rimonabant for 12 weeks reduced both ALT and weight (p < 0.01), and there was a negative correlation between Δ ALT and Δ HOMA-IR (p < 0.001), but not between Δ ALT and Δ weight. There was a significant reduction of weight with orlistat (p < 0.01); however, orlistat, metformin and pioglitazone had no effect on ALT. The free androgen index fell in all groups (p < 0.05). The inflammatory marker hs-CRP was reduced by pioglitazone (p < 0.001) alone and did not correlate with changes in ALT. The inflammatory cytokine profile for IL-1β, IL-6, IL-7, IL-10, IL12, TNF-α, MCP-1 and INF-γ did not differ between groups. None of the interventions had an effect on biological variability of ALT.

CONCLUSION

Rimonabant through CB1 receptor blockade decreased serum ALT that was independent of weight loss and hepatic inflammatory markers in obese women with PCOS without NAFLD.

TRIAL REGISTRATION

ISRCTN58369615 (February 2007; retrospectively registered) ISRCTN75758249 (October 2007; retrospectively registered).

Salivary testosterone measurement in women with and without polycystic ovary syndrome

Clinical and/or biochemical hyperandrogenism is one of the diagnostic criteria for PCOS. An evaluation of the role of salivary testosterone (salT) and androstenedione (salA) for the diagnosis of PCOS was undertaken in a cross sectional study involving 65 women without PCOS and 110 women with PCOS fulfilling all 3 diagnostic Rotterdam criteria. Serum and salivary androgen measurements were determined by LC-MS/MS. salT and salA were significantly elevated in PCOS compared to controls (P < 001). No androgen marker was more predictive than another using ROC curves, but multiple logistic regression suggested salT was more predictive than free androgen index (FAI) (p < 0.01). The combination of salT or FAI identified 100% of PCOS women. PCOS women with both biochemical and clinical hyperandrogenism as opposed to clinical hyperandrogenism alone showed a metabolic phenotype (p < 0.05) and insulin resistance (p < 0.001). PCOS patients with an isolated elevated FAI showed increased insulin resistance compared to those with an isolated salT (P < 0.05). salT appeared to be at least as predictive as FAI for the diagnosis of the classical PCOS phenotype, and the combination of salT or FAI identified 100% of PCOS patients. This suggests that salT measurement by LC-MS/MS holds the promise of complementing existing laboratory tests as a means of assessing hyperandrogenemia.

Androsterone glucuronide to dehydroepiandrosterone sulphate ratio is discriminatory for obese Caucasian women with polycystic ovary syndrome

BACKGROUND

Androsterone glucuronide (ADTG) concentrations have been suggested as a marker of the effects of androgens at the target tissue level. As the mechanism for hyperandrogenemia in obese and nonobese polycystic ovary syndrome (PCOS) may differ, this study compared the different androgen parameters in non-obese compared to obese women with PCOS, and in normal subjects.

METHODS

Eleven non-obese and 14 obese women with PCOS were recruited and compared to 11 control women without PCOS. Total testosterone, dehydroepiandrosterone sulphate (DHEAS), ADTG, and androstenedione were analysed using gold standard tandem mass spectrometry, and the free androgen index (FAI) was calculated.

RESULTS

Total testosterone, ADTG and androstendione levels did not differ between non-obese (body mass index (BMI) ≤25 kg/m²) and obese PCOS (BMI >25 kg/m²) but all were significantly higher than for controls (p < 0.01). The ADTG to DHEAS ratio was significantly elevated 39 ± 6 (p < 0.01) in obese PCOS in comparison to non-obese PCOS and controls (28 ± 5 and 29 ± 4, respectively). The free androgen index (FAI) and insulin resistance (HOMA-IR) were significantly higher in obese PCOS compared to non-obese PCOS and controls (p < 0.01). DHEAS was significantly higher in the non-obese versus obese PCOS (p < 0.01). All androgen parameters were significantly lower and sex hormone binding globulin (SHBG) significantly higher in normal subjects compared to those with obese and non-obese PCOS.

CONCLUSIONS

The ADTG:DHEAS ratio was significantly elevated in obese PCOS compared to non-obese PCOS and controls suggesting that this may be a novel biomarker discriminatory for obese PCOS subjects, perhaps being driven by higher hepatic 5α reductase activity increasing ADTG formation in these women.

Comparison of method-related reference intervals for thyroid hormones: studies from a prospective reference population and a literature review

Introduction

Reference intervals are dependent on the reference population, the analytical methods and the way the data are handled statistically. Individual method-related differences have been studied but the comparative differences in reference intervals have not.

Methods

We studied a reference population of healthy adult subjects and measured free thyroxine and thyroid-stimulating hormone by the four most commonly used analytical platforms used in the UK. Subjects were excluded if they were > 65 years or had positive thyroid peroxidase antibodies. We also performed a systematic literature review of thyroid hormone reference interval studies in non-pregnant adults.

Results

In total, 303 subjects were recruited and 42 excluded. The central 95th centile values for thyroid-stimulating hormone (mIU/L) were Abbott Architect (0.51–3.67); Beckman Unicel DxI (0.57–3.60); Roche Cobas (0.60–4.31) and Siemens Advia Centaur XP (0.63–4.29). The 95th centile values for thyroxine (pmol/L) were Abbott Architect (10.6–15.5); Beckman Unicel DxI (7.9–13.0); Roche Cobas (12.5–19.6) and Siemens Advia Centaur XP (11.8–19.0). We identified 55 papers describing thyroid reference intervals in male and non-pregnant female adults. The values for upper and lower reference intervals by manufacturer varied but were not significantly different for thyroid-stimulating hormone but were for thyroxine.

Discussion

Our study demonstrates clearly that there are marked variations in the reference intervals for thyroid hormones between analytical platforms. There is an urgent need for standardization of thyroid hormone assays to permit transferability of results. Until then, guidelines will need to reflect this method-related difference.

Soy Protein Improves Cardiovascular Risk in Subclinical Hypothyroidism: A Randomized Double-Blinded Crossover Study

Background:

Soy protein with isoflavones appears to have an adverse effect on thyroid function, but it is not known whether it is the protein or isoflavone component that is deleterious. The effect of isoflavone-free soy on thyroid function was determined in patients with subclinical hypothyroidism, with a secondary aim of assessing its effect on cardiovascular risk indices.

Methods:

This was a randomized, double-blind, crossover study involving 80 patients with subclinical (compensated) hypothyroidism. Patients were randomly assigned to either isolated soy (isoflavone-free) protein (SP) or casein protein (CP) supplementation for 8 weeks, washed out for 8 weeks, and then crossed over for a further 8-week period.

Results:

Thyroid function was unaffected by either a SP or CP. There were significant decreases in fasting glucose (4.7 ± 0.6 vs 5.5 ± 1.4, P < 0.01), insulin resistance (3.3 ± 3.0 vs 3.8 ± 3.4, P = 0.05), total cholesterol (4.4 ± 0.9 vs 5.3 ± 1.2, P < 0.01), triglycerides (0.9 ± 0.5 vs 1.7 ± 0.9, P < 0.1), and highly sensitive C-reactive protein (hsCRP; 0.8 ± 0.7 vs 2.6 ± 2.8, P < 0.01) in the SP group compared with the CP group. Blood pressure, low-density lipoprotein, and high-density lipoprotein remained unchanged in both groups.

Conclusion:

SP alone had no effect on thyroid function in patients with subclinical hypothyroidism and resulted in a significant reduction in fasting glucose, insulin resistance, total cholesterol, triglycerides, and hsCRP compared with CP.

A Fixed Ratio Combination of Insulin Degludec and Liraglutide (IDegLira) Reduces Glycemic Fluctuation and Brings More Patients with Type 2 Diabetes Within Blood Glucose Target Ranges

BACKGROUND

Reducing glycemic fluctuation is important for optimal diabetes management. This post hoc analysis examined glycemic fluctuations and the proportion of subjects achieving recommended blood glucose targets with the fixed ratio combination of insulin degludec and liraglutide (IDegLira) compared to insulin degludec (IDeg) and liraglutide alone.

METHODS

We analyzed nine-point self-monitored blood glucose (SMBG) profiles from two randomized trials involving IDegLira in patients with type 2 diabetes (T2D), and continuous glucose monitoring (CGM) data from a subset of patients in one of these trials to assess glycemic fluctuation and day-to-day variability.

RESULTS

Compared with IDeg, IDegLira resulted in a greater proportion of subjects with SMBG values within target ranges (3.9-9.0 mmol/L) than IDeg for all pre- and postprandial values, and for the full nine-point profile (P < 0.05 for all). IDegLira also resulted in a greater reduction in the range of SMBG values over 24 h than IDeg (P ≤ 0.0001). CGM data showed that IDegLira provided greater reductions in interstitial glucose (IG) fluctuation (P = 0.0018) and postprandial IG increment (P = 0.0288) compared with IDeg. Compared with liraglutide, IDegLira brought a higher proportion of subjects within SMBG target ranges (all pre- and all postprandial values, and the full nine-point profile, P < 0.01 for all) and resulted in a greater reduction of time outside the IG target range (P = 0.0072). IDegLira also reduced mean IG more than liraglutide (P < 0.0001).

CONCLUSIONS

Treatment with IDegLira allows more patients with T2D to maintain blood glucose within target ranges throughout the day than either IDeg or liraglutide alone.

Endocannabinoid receptor blockade increases vascular endothelial growth factor and inflammatory markers in obese women with polycystic ovary syndrome

CONTEXT

Animal studies suggest that cannabinoid receptor-1 (CB-1) blockade reduces inflammation and neovascularization by decreasing vascular endothelial growth factor (VEGF) levels associated with a reduction in inflammatory markers, thereby potentially reducing cardiovascular risk.

OBJECTIVE

To determine the impact of CB1 antagonism by rimonabant on VEGF and inflammatory markers in obese PCOS women.

DESIGN

Randomized, open-labelled parallel study.

SETTING

Endocrinology outpatient clinic in a referral centre.

SUBJECTS

Twenty patients with PCOS (PCOS) and biochemical hyperandrogenaemia with a body mass index of ≥30 kg/m² were recruited. Patients were randomized to 1·5 g daily of metformin or 20 mg daily of rimonabant.

MAIN OUTCOME MEASURES

Post hoc review to detect VEGF and pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 before and after 12 weeks of treatment.

RESULTS

After 12 weeks of rimonabant treatment, there was a significant increase in VEGF (99·2 ± 17·6 vs 116·2 ± 15·8 pg/ml, P < 0·01) and IL-8 (7·4 ± 11·0 vs 18·1 ± 13·2 pg/ml, P < 0·05) but not after metformin (VEGF P = 0·7; IL-8 P = 0·9). There was no significant difference in the pro-inflammatory cytokines TNF-α, IL-1β, IL-1ra, IL-2, IL6, IL-8, IL-10 and MCP-1 following either treatment.

CONCLUSION

This study suggests that rimonabant CB-I blockade paradoxically raised VEGF and the cytokine IL-8 in obese women with PCOS that may have offset the potential benefit associated with weight loss.

Effect of Soy in Men With Type 2 Diabetes Mellitus and Subclinical Hypogonadism: A Randomized Controlled Study

CONTEXT

Isoflavones found in soy products have a chemical structure similar to estrogen, leading to concerns of an adverse estrogenic effect in men, particularly in those with type 2 diabetes mellitus (T2DM) who have low testosterone levels due to hypogonadism.

OBJECTIVE

The primary outcome was change in total testosterone levels. The secondary outcomes were the changes in glycemia and cardiovascular risk markers.

DESIGN

This was a randomized double-blind parallel study.

SETTING

This study occurred in a secondary care setting in United Kingdom.

PARTICIPANTS

Two hundred men with T2DM and a total testosterone level ≤12 nmol/L were included.

INTERVENTION

Fifteen grams of soy protein with 66 mg of isoflavones (SPI) or 15 g soy protein alone without isoflavones (SP) daily as snack bars for 3 months were administered.

RESULTS

There was no change in either total testosterone or in absolute free testosterone levels with either SPI or SP. There was an increase in thyrotropin (TSH) and reduction in free thyroxine (fT4; P < 0.01) after SPI supplementation. Glycemic control improved with a significant reduction in hemoglobin A1c (-4.19 [7.29] mmol/mol, P < 0.01) and homeostasis model of assessment - insulin resistance after SPI. Cardiovascular risk improved with a reduction in triglycerides, C-reactive protein, and diastolic blood pressure (DBP; P < 0.05) with SPI vs SP supplementation. There was a 6% improvement in 10-year coronary heart disease risk after 3 months of SPI supplementation. Endothelial function improved with both SPI and SP supplementation (P < 0.01), with an increased reactive hyperemia index that was greater for the SPI group (P < 0.05).

CONCLUSIONS

Testosterone levels were unchanged and there was a substantial improvement in glycaemia and cardiovascular risk markers with SPI compared with SP alone over 3 months. There was also a substantial increase in TSH and a reduction in fT4.

Soy Reduces Bone Turnover Markers in Women During Early Menopause: A Randomized Controlled Trial

Menopausal estrogen loss leads to an increased bone loss. Soy isoflavones can act as selective estrogen receptor modulators, their role in bone turnover is unclear. The primary outcome was assessing changes in plasma bone turnover markers. The secondary outcomes were assessing changes in cardiovascular risk markers including insulin resistance, blood pressure, and lipid profile. We performed a double-blind randomized parallel study in which 200 women within 2 years after the onset of their menopause were randomized to 15 g soy protein with 66 mg isoflavone (SPI) or 15 g soy protein alone (SP), daily for 6 months. There was a significant reduction in type I collagen crosslinked beta C-telopeptide (βCTX) (bone-resorption marker) with SPI supplementation (0.40 ± 0.17 versus 0.15 ± 0.09 μg/L; p < 0.01) compared to SP supplementation (0.35 ± 0.12 versus 0.35 ± 0.13 μg/L; p = 0.92) after 6 months. There was also a significant reduction in type I procollagen-N-propeptide (P1NP) (bone formation marker) with SPI supplementation (50.5 ± 25.0 versus 34.3 ± 17.6 μg/L; p < 0.01), more marked between 3 and 6 months. Following SPI there was a significant reduction in fasting glucose, fasting insulin, insulin resistance, and systolic blood pressure whereas no significant changes in these parameters was observed with SP. There were no significant changes in fasting lipid profile and diastolic blood pressure with either preparation. There was a significant increase in TSH and reduction in free thyroxine (p < 0.01) with SPI supplementation though free tri-iodothyronine was unchanged. In conclusion, soy protein with isoflavones may confer a beneficial effect on bone health, analogous to the mode of action of antiresorptive agents, albeit to a less magnitude. There was a significant improvement of cardiovascular risk markers, but a significant increase in TSH and reduction in free thyroxine after SPI supplementation indicating a detrimental effect on thyroid function. © 2016 American Society for Bone and Mineral Research.

Stability of creatinine with delayed separation of whole blood and implications for eGFR

Background: The stability of creatinine in whole blood is unclear: it is not known if analysis of creatinine in samples with delayed separation could lead to misclassification of chronic kidney disease (CKD) using estimated glomerular filtration rate (eGFR).

Methods: Multiple blood samples were taken at a single time-point from five individuals and subject to varying time delays prior to centrifugation, after which serum was separated and analysed for creatinine by five different methods. The effect of time delay on eGFR was further investigated by measuring creatinine on duplicate patient samples arriving in the laboratory after immediate and delayed centrifugation.

Results: A significant increase in creatinine was seen by 24 h using kinetic Jaffe methods ( P<0.025). Over a period of 31 h creatinine concentration was stable using enzymatic creatinine assays. Using duplicate patient samples, four of 21 patients where specimens were delayed in the laboratory by more than 10 h showed a misclassification of CKD.

Conclusion: Delays in sample receipt can lead to significant increases in measured creatinine and misclassification of CKD. Enzymatic creatinine assays are reliable with respect to delayed sample receipt over the time course studied.

Hypopituitarism presenting as a mixed hyperlipidaemia

A case report is presented of a 37-year-old man who, largely by chance, was found to have a marked mixed hyperlipidaemia. As a teenager he had been treated for apparent idiopathic growth hormone deficiency, but had also never developed secondary sexual characteristics. Pituitary hormone measurement was now consistent with hypopituitarism and magnetic resonance imaging showed hypoplasia of his pituitary stalk as the likely cause. His hyperlipidaemia improved after appropriate hormone replacement. He thus appears to have had a mixed hyperlipidaemia secondary to hypopituitarism, which was secondary to a pituitary stalk abnormality, which in turn may have been associated to the trauma surrounding his normal breech delivery.