Polycystic ovary syndrome has no independent effect on vascular, inflammatory or thrombotic markers when matched for obesity

INTRODUCTION

Previous studies investigating cardiovascular (CV) risk in obese women with polycystic ovary syndrome (PCOS) have been potentially confounded by not adequately accounting for body weight.

OBJECTIVE

To assess if PCOS increases CV risk independently in young obese women by examining carotid intima-media wall thickness (cIMT) and platelet function.

DESIGN

A case-control study comparing women with PCOS (n = 21) to age (32·8 ± 7·2 vs 33·5 ± 6·7 years), and weight (100·9 ± 16·7 vs 99·3 ± 14·7 kg)-matched controls (n = 19). Platelet function was examined by flow cytometry, clot structure and fibrinolysis by turbidimetric assays and endothelial function by ELISA and post ischaemic reactive hyperaemia.

RESULTS

The PCOS group had higher testosterone 1·2 ± 0·3 vs 0·9 ± 0·3 nmol/l (P = 0·01), HOMA-IR 2·5 ± 1·7 vs 1·7 ± 1·0 (P = 0·08), impaired glucose regulation 33·3% vs 5·3% (P = 0·02), and urinary isoprostane 16·0 ± 4·4 vs 11·8 ± 7·1 ng/ml (P = 0·04) compared to controls. Mean cIMT 0·5 ± 0·05 vs 0·48 ± 0·06 mm (P = 0·36), and basal platelet surface expression (percentage of positive cells) of P-selectin 0·52 ± 0·3 vs 0·43 ± 0·23 (P = 0·40) and fibrinogen binding 0·97 ± 0·4 vs 0·83 ± 0·3 (P = 0·48) did not significantly differ between the PCOS and control groups respectively. Furthermore, platelets sensitivity to stimulation with adenosine-5'-diphosphate or inhibition with prostacyclin, clot structure and fibrinolytic efficiency ex vivo, endothelial reactive hyperaemic index (RHI), inflammation (hsCRP) and adhesion markers (sE-selectin, sP-selectin, sVCAM-1 and sICAM-1) were not significantly different between the two groups.

CONCLUSIONS

PCOS appeared not to independently increase atherothrombotic risk when matched for obesity. It is likely that any excess CV risk in young obese women with PCOS can either be attributed to obesity or is not yet apparent at this early stage of the condition.

The effect of atorvastatin and simvastatin on vitamin D, oxidative stress and inflammatory marker concentrations in patients with type 2 diabetes: a crossover study

The pleiotropic effect of statins may be mediated in part through raising 25 hydroxy vitamin D (25OHD) concentrations. It has also been shown that an increase in oxidative stress and inflammatory markers are a feature of the patients with type 2 diabetes (T2DM). A cross-over study of 26 patients with T2DM taking either simvastatin 40 mg or atorvastatin 10 mg was undertaken. After 3 months on one statin, lipids, C-reactive protein (hsCRP), 25OHD and malondialdehyde (MDA) were measured repeatedly. The same procedure was then followed taking the other statin. Despite similar lipid-lowering, the mean 25OHD was higher on atorvastatin compared with simvastatin and the mean MDA and hsCRP levels lower, irrespective of which statin the patients were taking before crossover. The changes in 25OHD predicted changes in CRP and MDA levels. Thus, compared with simvastatin, atorvastatin shows apparently beneficial pleiotropic effects with respect to 25OHD concentrations as well as markers of oxidative stress and inflammation in patients with T2DM.

Implications of new European Union driving regulations on patients with Type 1 diabetes who participated in the Diabetes Control and Complications Trial

AIMS

Recurrent severe hypoglycaemia in a patient with diabetes is strongly associated with a crash risk while driving. To help ensure road safety, recent changes were made to European Union driving regulations for patients with diabetes. These included the recommendation that more than one episode of severe hypoglycaemia within 12 months would lead to the loss of a driving licence. This study has assessed the impact of this regulation if applied to patients who participated in the Diabetes Control and Complications Trial.

METHODS

All patients in the Diabetes Control and Complications Trial were assumed to be drivers. Repeated hypoglycaemic episodes within a year were determined during the mean 6.5 years of the study.

RESULTS

Of the 1441 patients in the Diabetes Control and Complications Trial, 439 (30%) had more than one severe hypoglycaemic episode during a 12-month period of their study participation. Amongst the study groups, 312/711 (44%) of intensively treated and 127/730 (17%) of conventionally treated patients would have lost their licence at some point during the trial. The risk of licence loss increased with lower mean HbA1c , longer duration of diabetes and younger age (all P < 0.001).

CONCLUSIONS

More than one episode of severe hypoglycaemia within a year was a frequent event in subjects in the Diabetes Control and Complications Trial, especially in intensively treated patients. If applied to current practice, improving road safety through these changes to European Union regulations could have a substantial impact on drivers who have Type 1 diabetes. This emphasizes the need to take into account the potential effects of severe hypoglycaemia in those who rely on a driving licence.

High-polyphenol chocolate reduces endothelial dysfunction and oxidative stress during acute transient hyperglycaemia in Type 2 diabetes: a pilot randomized controlled trial

AIMS

To investigate the effects of high-polyphenol chocolate upon endothelial function and oxidative stress in Type 2 diabetes mellitus during acute transient hyperglycaemia induced following a 75-g oral glucose challenge.

METHODS

Ten subjects with Type 2 diabetes underwent a double-blinded randomized controlled crossover study. A 75-g oral glucose load was used to induce hyperglycaemia, which was administered to participants 60 min after they had ingested either low (control) or high-polyphenol chocolate. Participants undertook testing at weekly intervals, following an initial cocoa-free period. Endothelial function was assessed by both functional [reactive hyperaemia peripheral artery tonometry (EndoPAT-2000) and serum markers (including intercellular adhesion molecule 1, P-selectin and P-selectin glycoprotein ligand 1]. Urinary 15-F2t-isoprostane adjusted for creatinine was used as an oxidative stress marker. Measurements were made at baseline and 2 h post-ingestion of the glucose load.

RESULTS

Prior consumption of high-polyphenol chocolate before a glucose load improved endothelial function (1.7 ± 0.1 vs. 2.3 ± 0.1%, P = 0.01), whereas prior consumption of control chocolate resulted in a significant increase in intercellular adhesion molecule 1 (321.1 ± 7.6 vs. 373.6 ± 10.5 ng/ml, P = 0.04) and 15-F2t-isoprostane (116.8 ± 5.7 vs. 207.1 ± 5.7 mg/mol, P = 0.02). Analysis of percentage changes from baseline comparing control and high-polyphenol chocolate showed a significant improvement for high-polyphenol chocolate in both measures of endothelial function (P < 0.05) and for urinary 15-F2t-isoprostane (P = 0.04).

CONCLUSION

High-polyphenol chocolate protected against acute hyperglycaemia-induced endothelial dysfunction and oxidative stress in individuals with Type 2 diabetes mellitus.

Diagnostic performance of using one- or two-HbA1c cut-point strategies to detect undiagnosed type 2 diabetes and impaired glucose regulation within a multi-ethnic population

INTRODUCTION

We compared test performance and cost per case for strategies detecting diabetes on the oral glucose tolerance test (OGTT) using either (a) glycated haemoglobin (HbA1c) ≥ 6.5% (48 mmol/mol) or (b) two HbA1c thresholds where the first cut-point 'rules out' and the second 'rules in' diabetes. HbA1c values in between the thresholds require confirmatory glucose testing for diagnosis.

MATERIALS AND METHODS

We conducted an analysis of adults aged 40-75 years from the Leicester Ethnic Atherosclerosis and Diabetes Risk (LEADER) cohort (Leicester, UK), from 2002 to 2008, who underwent oral glucose tolerance testing (OGTT) and HbA1c testing.

RESULTS

From 8696 individuals (mean age 57.3 years, 73% white Europeans (WE) and 27% South Asians (SA)), HbA1c ≥ 6.5% produced sensitivity of 62.1% for detecting diabetes in WE and 78.9% in SA. Using two selected thresholds, HbA1c ≤ 5.8% (rule-in, 40 mmol/mol) and HbA1c ≥ 6.8% (rule-out, 51 mmol/mol) produced high sensitivity/specificity (> 91.0%) for detecting diabetes, however, 28.8% of the cohort with HbA1c 5.9%-6.7% required a subsequent glucose test. The two cut-point threshold produced a lower cost per case of diabetes detected in WE, compared to HbA1c ≥ 6.5% of £38.53 (1.89 to 86.81) per case, but was more expensive in SA by £84.50 (69.72 to 100.92) per case. Using a risk score to determine HbA1c testing, the same costs per case became £63.33 (23.33 to 113.26) in WE and £69.21 (55.60 to 82.41) in SA.

CONCLUSION

Using a two-threshold strategy may have some benefits over a single cut-point; however, 28.8% of individuals required two blood tests.

Atorvastatin reduces malondialdehyde concentrations in patients with polycystic ovary syndrome

BACKGROUND

It has been shown that there is an increase in oxidative stress in polycystic ovary syndrome (PCOS). Statins are considered to have a pleiotropic effect other than their lipid-lowering effect. These effects may be mediated in part by reducing oxidative stress.

METHODS

This randomized, double-blind, placebo-controlled study was conducted to assess the effect of atorvastatin on serum malondialdehyde (MDA) concentrations as a marker of oxidative stress in patients with PCOS. Forty medication-naïve patients with PCOS were randomized 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 decrease of MDA concentrations with atorvastatin [mean (sem)] [0.29 (0.04) vs. 0.25 (0.02) μmol/liter; P < 0.01] compared with placebo [0.28 (0.02) vs. 0.29 (0.12) μmol/liter; P = 0.52]. Three months treatment with metformin resulted in further reduction of MDA levels with atorvastatin compared with baseline [0.25 (0.02) baseline vs. 0.23 (0.03) μmol/liter for atorvastatin treated; P = 0.02]. There was also a significant correlation between the reduction in MDA with a reduction in high-sensitivity C-reactive protein (r = 0.71, P < 0.01), an increase in 25-hydroxyvitamin D (25OHD; r = -0.68, P = 0.02), and a reduction in testosterone levels (r = 0.63, P = 0.01). Multiple linear regression analysis revealed Δ25OHD, ΔC-reactive protein, and Δtestosterone were independent predictors of changes in MDA after atorvastatin treatment. No correlation was observed between the reductions in serum MDA concentrations with changes in the lipid parameters.

CONCLUSIONS

Twelve weeks of atorvastatin led to a significant reduction in oxidative stress as determined by MDA concentrations among patients with polycystic ovary syndrome that was independently predicted by changes in testosterone, 25OHD, and high-sensitivity C-reactive protein.

Using multiple measures of glycemia to support individualized diabetes management: recommendations for clinicians, patients, and payers

By the year 2030, the diabetes pandemic will likely affect more than 10% of the world's population. The personal, public health, and economic crises implicit in this trend call for decisive action. Yet, escalating dilemmas thwart full realization of current therapies. First, controversial studies, such as the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Trial, have amplified calls to individualize glycated hemoglobin (A1C) targets in the absence of adequate infrastructures for supporting personalized care. Second, costlier medications and technologies addressing more nuanced aspects of metabolic dysfunction are expanding options for diabetes management amidst growing disparities between "affordable" and "best" care. Third, common clinical quandaries, such as discrepancies between A1C and self-monitoring of blood glucose data, as well as misconceptions about long-term glycemic assessment, compound entrenched cycles of inadequate self-care, delayed intervention, and suboptimal glycemic outcomes. Because individual, clinical, and public policy responses to these conflicting forces are based largely on methodologies for glucose measurement, a panel of clinical experts from Europe and North America was convened to reexamine our glucose measuring tools and determine ways in which they can be better applied toward more purposeful processes of glycemic management. Among the main issues addressed were the need for caution in interpreting A1C for individual patients, the role of alternative biomarkers in identifying aspects of glycemic dysregulation not captured by A1C, and the value of using patients' own glucose data to consolidate therapeutic, educational, and behavior-change objectives.

Short-term glucose variability in healthy volunteers is not associated with raised oxidative stress markers

It is unknown whether glycaemic variability adds to the risk of microvascular complications of diabetes over and above the mean glucose value for a patient. We examined the effect of purposefully induced short-term glycaemic variability on oxidative stress markers. Eleven healthy subjects underwent three sequential glycaemic states; sustained hyperglycaemia, sustained euglycaemia and variable glycaemia, using glycaemic clamps for 3 h. Twenty-four hours urinary 8-isoprostane-PGF2α was measured before and after each glycaemic state to assess oxidative stress. The median and interquartile range of the urinary 8-iso-PGF2α in ng/24 h were (1373, 513), (996, 298) and (1227, 472) for the euglycaemic, hyperglycaemic and variable states, respectively. There was no significant difference in urinary isoprostanes between the three different states; mean ranks 20.9, 11.9 and 18.2 for the euglycaemic state, hyperglycaemic state and glycaemic variability state, respectively, p = 0.083. In conclusion, we did not see a significant increase in the urinary isoprostanes when glycaemic variability was induced under controlled conditions in healthy individuals.

Does severe hypoglycaemia influence microvascular complications in Type 1 diabetes? An analysis of the Diabetes Control and Complications Trial database

AIMS

Severe hypoglycaemia may have a role in aggravating micro- and macrovascular disease in diabetes. Data from the Diabetes Control and Complication Trial have been reanalysed to ascertain whether the frequency of severe hypoglycaemia exerted an influence on the development and progression of retinopathy or nephropathy in people with Type 1 diabetes.

METHODS

Using binary longitudinal multiple logistic regression, HbA(1c) at study baseline, mean HbA(1c) throughout the study and the number of severe hypoglycaemic episodes during the trial were compared to examine the risk of development/progression of retinopathy and nephropathy.

RESULTS

Average HbA(1c) during the study and/or HbA(1c) at baseline were independently predictive of retinopathy and nephropathy both in the intensively and the conventionally treated patients (all P ≤ 0.001). However, the number of hypoglycaemic episodes did not add to HbA(1c) in predicting retinopathy [odds ratio (95% CI) 0.99 (0.96-1.01), P = 0.51 in intensively treated patients, 0.94 (0.89-1.00), P = 0.05, conventional] or nephropathy [odds ratio (95% CI) 0.98 (0.95-1.01), P = 0.48 intensive, 1.03 (0.98-1.10), P = 0.17 conventional].

CONCLUSIONS

The frequency of exposure to severe hypoglycaemia did not predict a different risk of developing retinopathy or nephropathy in either treatment group of the Diabetes Control and Complications Trial at any given HbA(1c) .

The rise and fall of HbA(1c) as a risk marker for diabetes complications

It is still unclear whether short-term, within-day, variability in glycaemic control is contributory to the development of diabetes micro- or macrovascular complications. However, consistent and compelling data are emerging that longer term fluctuations in glucose, as evidenced by increases in HbA(1c) variability, do indeed add to the mean HbA(1c) value in predicting the risk of microvascular disease. Until now, studies have found this to be the case mainly in type 1 diabetes, but in this issue of Diabetologia (DOI: 10.1007/s00125-012-2572-7 ) an analysis of the Tsukuba Kawai Diabetes Registry in Japan has found that HbA(1c) variability also predicts the risk of nephropathy in type 2 diabetic patients. These observations raise the possibility that reducing rises and falls in HbA(1c) may help avoid hyperglycaemia-related vascular disease without running the same risk of hypoglycaemia that a strategy focusing purely on lower HbA(1c) might incur.

Atorvastatin therapy decreases androstenedione and dehydroepiandrosterone sulphate concentrations in patients with polycystic ovary syndrome: randomized controlled study

BACKGROUND

Hyperandrogenaemia in polycystic ovary syndrome (PCOS) represents a composite of raised serum concentrations of testosterone, androstenedione, dehydroepiandrosterone (DHEA) and DHEA sulphate (DHEAS). In patients with PCOS, testosterone and androstenedione are primarily derived from the ovaries and DHEAS is a metabolite predominantly from the adrenals. It has been shown that atorvastatin reduces testosterone concentrations in patients with PCOS. The objective was to study the effect of atorvastatin on serum androstenedione and DHEAS concentrations in patients with PCOS.

METHODS

A randomized, double-blind, placebo-controlled study was performed. Forty medication-naive patients with PCOs were randomized to either atorvastatin 20mg daily or placebo for three months. Subsequently, a three-month extension study for all patients was undertaken with metformin 1500 mg daily. The main outcome measures were change in androstenedione and DHEAS concentrations.

RESULTS

The mean (SD) baseline androstenedione (5.7 [0.8] versus 5.6 [1.3] nmol/L; P = 0.69) and DHEAS (7.1 [1.0] versus 7.2 [1.2] μmol/L; P = 0.72) concentrations were comparable between two groups. There was a significant reduction of androstenedione (5.7 [0.8] versus 4.7 [0.7] nmol/L; P = 0.03) and DHEAS (7.1 [1.0] versus 6.0 [0.9] μmol/L; P = 0.02) with three months of atorvastatin while there were no significant changes with placebo. Three months' treatment with metformin maintained the reduction of androstenedione and DHEAS concentrations with atorvastatin compared with baseline. There were no changes in either DHEAS or androstenedione concentrations in the initial placebo group after 12 weeks of metformin.

CONCLUSIONS

Twelve weeks of atorvastatin significantly reduced both DHEAS and androstenedione contributing to the total reduction of androgen concentrations and indicating that the reduction of the hyperandrogenaemia could be partly due to the action of atorvastatin at both the ovary and the adrenal gland in PCOS.

A national audit of estimated glomerular filtration rate and proteinuria reporting in the UK

BACKGROUND

Within the UK there has been a rapid move to include the reporting of estimated glomerular filtration rate (eGFR) values to identify patients with chronic kidney disease (CKD). Guidance has also changed since its original introduction. This national audit aimed to establish how eGFR is reported by laboratories within the UK.

METHODS

A questionnaire was sent to 164 UK National Health Service laboratories, which included questions on the patient groups who had eGFR reported, the eGFR thresholds used, adjustments made for ethnicity and the means of identifying proteinuria. The audit standards used were based on the 2008 National Institute for Health and Clinical Excellencec (NICE) CKD guidance.

RESULTS

One hundred and thirty-one of the 164 laboratories (80%) responded. Forty-six percent reported eGFR on all adult requests while 36% limited use to general practitioners. Twenty-one percent did not issue eGFR to any inpatient. Sixty-two percent and 30% of laboratories had an upper reporting limit of ≥90 and ≥60 mL/min/1.73 m(2), respectively; the remainder having higher thresholds. Sixty percent cited an ethnicity 'correction factor' on the report, 59% in a guideline but 28% in neither. An albumin:creatinine ratio was used by 63% to detect non-diabetic proteinuria, while 37% exclusively used a protein:creatinine ratio.

CONCLUSIONS

There has been rapid implementation of eGFR reporting in the UK since 2006. However, there is considerable variation in the way it is reported, with few laboratories currently exactly matching existing NICE recommendations. A reassessment of biochemical CKD assessment by most laboratories following a reiteration and clarification of current recommendations seems warranted.

A national survey of interpretative reporting in the UK

Aims

There is still debate as to whether the addition of interpretative comments to laboratory reports can influence the management of patients. Little is known about the extent of this activity in individual laboratories throughout the UK and so this national survey aimed to establish the prevalence.

Methods

An electronic questionnaire was sent to 196 NHS laboratories in the UK asking whether 17 commonly requested groups of tests were reported with interpretative comments and, if so, how laboratory computers and/or humans were involved in the process. Enquiries were also made of the grades of staff performing the process and of any ‘vignette’ examples where interpretative reporting had improved the clinical outcome for the patient.

Results

A total of 138 of the 196 laboratories (70%) responded. Only two laboratories did not have staff adding interpretative comments to any of the 17 tests. Consultant laboratory staff reporting predominated in all tests with a significant minority also being added by biomedical scientists. High-volume requests usually had staff adding comments to results selected by computer rules whereas more of the specialist endocrine tests tended to be considered for comment. Only six of 71 vignettes referred specifically to ‘routine’ biochemistry.

Conclusions

The addition of interpretative comments onto clinical biochemistry reports is widespread throughout the UK. This service is largely consultant led. There is anecdotal evidence that the process can influence the clinical management of patients.

The effect of extensive flooding in Hull on the glycaemic control of patients with diabetes

AIMS

To examine the impact of extensive flooding in a UK city in 2007 on the glycaemic control of patients with diabetes mellitus.

METHODS

This was a longitudinal study in patients with diabetes mellitus 12 months before and after the floods in Hull and East Yorkshire, UK. All patients registered with diabetes mellitus were sent questionnaires about their experiences during and after the floods. Glycaemic control for patients directly affected by the floods was compared against those unaffected.

RESULTS

Of 1743 respondents, 296 patients had been affected by the floods (110 insulin treated, 186 lifestyle and oral agents) and 1447 unaffected (482 insulin treated, 965 lifestyle and oral agents). There was a rise in mean HbA(1c) of affected individuals comparing 12 months before the floods with 12 months after [mean (95% confidence interval), 7.6% (7.5-7.7) vs. 7.9% (7.7-8.0), P = 0.002], but not those unaffected [7.5% (7.4-7.6) vs. 7.5% (7.4-7.6), P = 0.46]. The difference was mainly in insulin-treated patients [8.6% (8.3, 8.9) affected vs. 8.2% (8.1, 8.3) unaffected, (P = 0.002)].

CONCLUSIONS

Glycaemic control deteriorated in diabetes patients following the floods but was almost exclusively confined to patients taking insulin and was worst at 6-9 months following the event. Insulin-treated patients may need specific targeting in the event of a natural disaster.

The effect of soy phytoestrogen supplementation on thyroid status and cardiovascular risk markers in patients with subclinical hypothyroidism: a randomized, double-blind, crossover study

CONTEXT

There is concern whether soy phytoestrogens may affect thyroid function. If true, soy phytoestrogens may be expected to have a greater impact in subjects with subclinical hypothyroidism.

OBJECTIVE

The primary aim was to determine the effect of soy phytoestrogen supplementation on thyroid function, with a secondary aim of assessing the effects on cardiovascular risk indices in patients with subclinical hypothyroidism.

DESIGN AND SETTING

We conducted a randomized, double-blind, crossover study in a tertiary care setting.

PARTICIPANTS

Sixty patients with subclinical hypothyroidism participated in the study.

INTERVENTION

Patients were randomly assigned to either low-dose phytoestrogen (30 g soy protein with 2 mg phytoestrogens, representative of a Western diet) or high-dose phytoestrogen (30 g soy protein with 16 mg phytoestrogens, representative of a vegetarian diet) supplementation for 8 wk, then crossed over after an 8-wk washout period.

MAIN OUTCOME MEASURES

The primary outcome was progression to overt hypothyroidism, with secondary outcome measures of blood pressure, insulin resistance, lipids, and highly sensitive C-reactive protein (hsCRP).

RESULTS

Six female patients in the study progressed into overt hypothyroidism with a standardized rate ratio of 3.6 (95% confidence interval, 1.9, 6.2) after 16-mg phytoestrogen supplementation. Both systolic and diastolic blood pressure decreased with 16 mg phytoestrogens, whereas systolic pressure alone decreased with 2 mg phytoestrogens. Insulin resistance (homeostasis model assessment of insulin resistance, 3.5 ± 0.09 vs. 2.6 ± 0.08; P < 0.02) and hsCRP (4.9 ± 0.04 vs. 3.9 ± 0.03; P < 0.01) decreased with 16 mg phytoestrogens. Lipid profile remained unchanged.

CONCLUSION

There is a 3-fold increased risk of developing overt hypothyroidism with dietary supplementation of 16 mg soy phytoestrogens with subclinical hypothyroidism. However, 16-mg soy phytoestrogen supplementation significantly reduces the insulin resistance, hsCRP, and blood pressure in these patients.

A comparison of methods for the measurement of 8-isoPGF(2α): a marker of oxidative stress

BACKGROUND

Oxidative stress describes the cellular damage caused by excess reactive oxygen species not adequately inactivated by antioxidants. Oxidative stress has been implicated in playing a role in many disorders. Lipid peroxidation end-products are employed as markers of oxidative stress, of which the isoprostane, 8-iso-PGF(2α), is widely used. 8-iso-PGF(2α) is measured in plasma or urine by gas chromatography-mass spectrometry (GC/MS), liquid chromatography-mass spectrometry (LC/MS), tandem-mass spectrometry or enzyme-linked immunosorbent assay (ELISA). However, discrepancies between the specificity of these methods means correlation is poor.

METHODS

A tandem-mass spectrometric (LC/MS/MS) method, using immunoaffinity purification, for urinary 8-iso-PGF(2α) was developed and compared with two commercial ELISAs (A--Cayman Chemicals, B--Oxford Biomedical Research) in urine samples (n = 156).

RESULTS

An LC/MS/MS method coupled to immunoaffinity purification was developed with satisfactory performance and comparison to ELISAs A and B. Spearman rank correlation demonstrated significant correlation between all methods (P = <0.0001); however, r² values ranged from 0.68 to 0.72. Bland-Altman plots revealed a proportional positive bias of ELISA B when compared with ELISA A and LC/MS/MS. Furthermore, the agreement between ELISA A and LC/MS/MS was poor.

CONCLUSIONS

The poor agreement between methods for measurement of 8-iso-PGF(2α) highlights differences in selectivity. 8-iso-PGF(2α) is an isoprostane, a family of isomeric end-products of arachidonic acid peroxidation, which are produced by peroxidation or enzymatically. This makes avoiding cross-reactivity between 8-iso-PGF(2α) and related isomers challenging. When assessing oxidative stress studies, the selectivity of the methods used should be taken into account, particularly when comparing studies.

Insulin resistance variability in women with anovulatory and ovulatory polycystic ovary syndrome, and normal controls

Women with polycystic ovary syndrome (PCOS) were found to have a higher biological variability in insulin resistance (IR) compared to controls, but it is unknown whether this variability in IR differs between PCOS who are anovulatory compared to those who have an ovulatory cycle. The primary aim of this study was to compare and contrast the variability of IR in women with ovulatory and anovulatory PCOS, in comparison to normal subjects. 53 Caucasian women with PCOS and 22 normal ovulating women were recruited. Fasting blood was collected each day on 10 consecutive occasions at 3-4 day intervals for analysis of insulin, glucose, progesterone, and testosterone. Analysis of progesterone levels showed 22 of 53 women with PCOS to have had an ovulatory cycle. Insulin resistance was calculated by HOMA method. Women with anovulatory PCOS had higher mean and variability of IR compared to those having an ovulatory cycle, and both were significantly higher than controls (mean ± SEM; HOMA-IR 4.14 ± 0.14 vs. 3.65 ± 0.15 vs. 2.21 ± 0.16, respectively) after adjustment or BMI. The mean BMI for individual PCOS patients correlated with mean HOMA-IR (p=0.009). Insulin resistance in women with anovulatory PCOS is both higher and more variable than in ovulatory PCOS. Since anovulatory PCOS therefore mimics the IR features of type 2 diabetes more closely, anovulation may be particularly associated with a higher cardiovascular risk compared to PCOS patients who ovulate.

The effect of iron and erythropoietin treatment on the A1C of patients with diabetes and chronic kidney disease

OBJECTIVE

To examine the effect of intravenous iron and erythropoietin-stimulating agents (ESAs) on glycemic control and A1C of patients with diabetes and chronic kidney disease (CKD).

RESEARCH DESIGN AND METHODS

This was a prospective study of patients with type 2 diabetes and CKD stage IIIB or IV undergoing intravenous iron (group A) and/or ESA (group B). Full blood profiles were determined over the study period. Glycemic control was monitored using A1C, seven-point daily glucose three times weekly, and continuous glucose monitoring (CGM).

RESULTS

There were 15 patients in both group A and group B. Mean A1C (95% CI) values fell in both groups (7.40% [6.60-8.19] to 6.96% [6.27-7.25], P<0.01, with intravenous iron and 7.31% [6.42-8.54] to 6.63% [6.03-7.36], P=0.013, ESA). There was no change in mean blood glucose in group A (9.55 mmol/l [8.20-10.90] vs. 9.71 mmol/l [8.29-11.13], P=0.07) and in group B (8.72 mmol/l [7.31-10.12] vs. 8.78 mmol/l [7.47-9.99], P=0.61) over the study period. Hemoglobin and hematocrit values significantly increased following both treatments. There was no linear relationship found between the change in A1C values and the rise of hemoglobin following either treatment.

CONCLUSIONS

Both iron and ESA cause a significant fall in A1C values without a change to glycemic control in patients with diabetes and CKD. At the present time, regular capillary glucose measurements and the concurrent use of CGM remain the best alternative measurements of glycemic control in this patient group.

The role of blood pressure variability in the development of nephropathy in type 1 diabetes

OBJECTIVE

Increases in blood pressure and visit-to-visit variability have both been found to independently increase the likelihood of cardiovascular events in nondiabetic individuals. This study has investigated whether each may also influence the development of microvascular complications in type 1 diabetes by examining data from the Diabetes Control and Complications Trial (DCCT).

RESEARCH DESIGN AND METHODS

Using binary longitudinal multiple logistic regression, mean systolic (SBP) and diastolic (DBP) blood pressure as well as annual visit-to-visit variability (SD.SBP and SD.DBP, respectively) was related to the risk of the development/progression of nephropathy and retinopathy in initially normotensive subjects who did not become pregnant during the DCCT.

RESULTS

Mean SBP and SD.SBP were independently predictive of albuminuria (odds ratio 1.005 [95% CI 1.002-1.008], P<0.001 and 1.093 [1.069-1.117], P<0.001, respectively, for 1 mmHg change), although SBP variability did not add to mean SBP in predicting retinopathy (0.999 [0.985-1.013], P=0.93). DBP variability was also independently predictive of nephropathy (1.102 [1.068-1.137], P<0.001) and not of retinopathy (0.991 [0.971-1.010], P=0.37). Mean SBP was poorly related to SD.SBP (r2<0.01) as was mean DBP with SD. DBP (r2<0.01).

CONCLUSIONS

Visit-to-visit variability in blood pressure consistently independently added to mean blood pressure in predicting the risk of nephropathy, but not retinopathy, in the DCCT. This observation could have implications for the management and treatment of blood pressure in patients with type 1 diabetes.

High-cocoa polyphenol-rich chocolate improves HDL cholesterol in Type 2 diabetes patients

AIM

To examine the effects of chocolate on lipid profiles, weight and glycaemic control in individuals with Type 2 diabetes.

METHODS

Twelve individuals with Type 2 diabetes on stable medication were enrolled in a randomized, placebo-controlled double-blind crossover study. Subjects were randomized to 45 g chocolate with or without a high polyphenol content for 8 weeks and then crossed over after a 4-week washout period. Changes in weight, glycaemic control, lipid profile and high-sensitivity C-reactive protein were measured at the beginning and at the end of each intervention.

RESULTS

HDL cholesterol increased significantly with high polyphenol chocolate (1.16 ± 0.08 vs. 1.26 ± 0.08 mmol/l, P = 0.05) with a decrease in the total cholesterol: HDL ratio (4.4 ± 0.4 vs. 4.1 ± 0.4 mmol/l, P = 0.04). No changes were seen with the low polyphenol chocolate in any parameters. Over the course of 16 weeks of daily chocolate consumption neither weight nor glycaemic control altered from baseline.

CONCLUSION

High polyphenol chocolate is effective in improving the atherosclerotic cholesterol profile in patients with diabetes by increasing HDL cholesterol and improving the cholesterol:HDL ratio without affecting weight, inflammatory markers, insulin resistance or glycaemic control.

Atorvastatin increases 25-hydroxy vitamin D concentrations in patients with polycystic ovary syndrome

BACKGROUND

It has been shown that many women with polycystic ovary syndrome (PCOS) are 25-hydroxyvitamin D (25OHD) insufficient. Both statin treatment and vitamin D supplementation have been shown to improve biochemical hyperandrogenemia, insulin resistance, and markers of inflammation in patients with PCOS, raising the possibility that some of the statin effects are mediated through vitamin D.

METHODS

We conducted this randomized, double-blind placebo controlled study to assess the effect of atorvastatin on serum 25OHD concentrations in patients with PCOS. Forty medication-naive patients with PCOS were randomized to either atorvastatin 20 mg daily or placebo for 3 months. After completing the initial 3 months of atorvastatin or placebo, both groups of patients participated in a 3-month extension study with metformin 1500 mg daily. We measured changes in 25OHD concentrations by use of tandem mass spectrometry.

RESULTS

Mean (SD) baseline 25OHD concentrations were comparable between the 2 groups [45.9 (2.4) vs 44.8 (1.8) nmol/L; P = 0.7]. There was a significant increase in 25OHD concentrations with atorvastatin [45.9 (2.4) vs 60.8 (3.5) nmol/L] compared with placebo [44.8 (1.8) vs 41.8 (3.2) nmol/L; P = 0.02]. Three-month treatment with metformin maintained the improvement of 25OHD with atorvastatin compared to baseline [45.9 (2.4) vs 61.8 (3.5), P ≤ 0.01). There were no significant changes in 25OHD concentrations in the placebo group after 12 weeks of metformin.

CONCLUSIONS

Among patients with polycystic ovary syndrome, 12 weeks of atorvastatin led to a clinically significant rise in 25OHD concentrations. This may represent a beneficial pleiotropic effect of statins on 25OHD concentrations.

Disparate effects of atorvastatin compared with simvastatin on C-reactive protein concentrations in patients with type 2 diabetes

OBJECTIVE

Reduction in LDL and high sensitivity (hs) C-reactive protein (CRP) are independent indicators of successful cardiovascular risk reduction with statins. This study compared the effect of equivalent LDL-lowering doses of simvastatin and atorvastatin on hsCRP in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

A crossover study of 26 patients with type 2 diabetes taking either 40 mg simvastatin or 10 mg atorvastatin was undertaken. After 3 months on one statin, lipids and hsCRP were measured on 10 occasions over a 5-week period. The same procedure was then followed taking the other statin.

RESULTS

LDL was comparable on either treatment: atorvastatin 2.2 +/- 0.2 vs. 2.1 +/- 0.3 mmol/l (mean +/- SD; P = 0.19). CRP of individuals taking atorvastatin was significantly lower than when they were taking simvastatin (median 1.08 vs. 1.47 mg/l, P = 0.0002) and was less variable (median SD of logCRP 0.0036 vs. 0.178, P = 0.0001).

CONCLUSIONS

Compared with simvastatin, atorvastatin reduced hsCRP and its variability in type 2 diabetic patients. This enhanced anti-inflammatory effect may prove beneficial if lower CRP is associated with improved cardiovascular risk.

For debate. Glucose variability and diabetes complication risk: we need to know the answer

There is still a debate as to whether or not glucose variability contributes to diabetes complication risk. There is much in vitro laboratory evidence that glycaemic instability gives rise to increased production of reactive oxygen species and has a detrimental effect on endothelial dysfunction. While some in vivo studies have also shown similar findings in patients with or without diabetes, others have been unable to confirm any association. Furthermore, clinical studies which have sought to translate this possible risk into an increased likelihood of developing micro- or macrovascular complications have so far not demonstrated an effect. However, few of these trials were specifically designed to establish any influence of glucose fluctuations. This issue is now one of the largest remaining unanswered questions in diabetes. While this article focuses on the data which do not support a role for glucose variability in the development of complications, it also highlights the need for further studies to be performed which will definitively resolve the matter.