The impact of specific fertility treatments on cognitive development in childhood and adolescence: a systematic review

STUDY QUESTION

Does fertility treatment influence cognitive ability in school aged children, and does the impact vary with the type of treatment?

SUMMARY ANSWER

The available high-quality evidence indicates that specific treatments may give rise to different effects on cognitive development, with certain treatments, including ICSI, associated with cognitive impairment.

WHAT IS KNOWN ALREADY

Previous reviews of the literature concerning cognitive outcomes among children conceived with medical assistance have concluded that study findings are generally 'reassuring', but limited attention has been paid to the quality of this research. In addition, no review has separately assessed the range of treatment modalities available, which vary in invasiveness, and thus, potentially, in their effects on developmental outcomes.

STUDY DESIGN, SIZE, DURATION

A systematic review was undertaken. We searched PubMed, PsycINFO and the Educational Resources Information Centre database to identify English-language studies published up until 21 November 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two authors independently reviewed identified articles, extracted data and assessed study quality. Studies were eligible if they assessed cognitive development from age 4 years or more, among children conceived with fertility treatment compared with either children conceived naturally or children born from a different type of fertility treatment. Where available, data were extracted and reported separately according to the various components of treatment (e.g. mode of fertilization, embryo freezing, etc.). Risk of bias was assessed using the Newcastle-Ottawa Scale, with a score ≥7/9 indicative of high quality.

MAIN RESULTS AND THE ROLE OF CHANCE

The search identified 861 articles, of which 35 were included. Of these, seven were rated high quality. Most studies (n = 22) were subject to selection bias, due to the exclusion of children at increased risk of cognitive impairment. Among high-quality studies, there was no difference in cognitive outcomes among children conceived with conventional IVF and those conceived naturally. Findings among high-quality studies of children conceived with ICSI were inconsistent: when compared with children conceived naturally, one study reported lower intelligence quotient (IQ; 5-7 points, on average) among ICSI children whereas the remaining two high-quality studies reported no difference between groups. Furthermore, among the three high-quality studies comparing children conceived with ICSI compared with conventional IVF, one reported a significant increase in the risk of mental retardation, one reported a small difference in IQ (3 points lower, on average) and one no difference at all. There were scant studies examining exposure to embryo freezing, or less invasive treatments such as ovulation induction without IVF/ICSI.

LIMITATION, REASONS FOR CAUTION

Most existing studies had methodological limitations including selection bias and/or failure to address confounding by family background. In addition, a meta-analysis could not be performed due to heterogeneity in the assessment of cognitive outcomes. These factors impeded our ability to synthesize the evidence and draw reliable conclusions.

WIDER IMPLICATIONS OF THE FINDINGS

The conflicting findings among studies of children conceived with ICSI require clarification, in light of the increasing use of this technique for reasons other than male-factor infertility. Further population-based studies are needed that utilize contemporary data to examine specific aspects of treatment and combinations of techniques (e.g. ICSI with frozen embryo cycles). Importantly, studies should include the complete group of children exposed to treatment.

STUDY FUNDING/COMPETING INTEREST(S)

A.R.R. is supported by a Career Development Fellowship from the National Health and Medical Research Council of Australia. L.J.M. is funded by a fellowship from the Heart Foundation of Australia. The authors declare there are no competing interests.

TRIAL REGISTRATION NUMBER

Not applicable.

Early events in copper-ion catalyzed oxidation of α-synuclein

Previous studies on metal-ion catalyzed oxidation of α-synuclein oxidation have mostly used conditions that result in extensive modification precluding an understanding of the early events in this process. In this study, we have examined time-dependent oxidative events related to α-synuclein modification using six different molar ratios of Cu²⁺/H₂O₂/protein and Cu²⁺/H₂O₂/ascorbate/protein resulting in mild to moderate extents of oxidation. For a Cu²⁺/H₂O₂/protein molar ratio of 2.3:7.8:1 only low levels of carbonyls were detected (0.078 carbonyls per protein), whereas a molar ratio of 4.7:15.6:1 gave 0.22 carbonyls per α-synuclein within 15 min. With the latter conditions, rapid conversion of 3 out of 4 methionines (Met) to methionine sulfoxide, and 2 out of 4 tyrosines (Tyr) were converted to products including inter- and intra-molecular dityrosine cross-links and protein oligomers, as determined by SDS-PAGE and Western blot analysis. Limited histidine (His) modification was observed. The rapid formation of dityrosine cross-links was confirmed by fluorescence and mass-spectrometry. These data indicate that Met and Tyr oxidation are early events in Cu²⁺/H₂O₂-mediated damage, with carbonyl formation being a minor process. With the Cu²⁺/H₂O₂/ascorbate system, rapid protein carbonyl formation was detected with the first 5 min, but after this time point, little additional carbonyl formation was detected. With this system, lower levels of Met and Tyr oxidation were detected (2 Met and 1 Tyr modified with a Cu²⁺/H₂O₂/ascorbate/protein ratio of 2.3:7.8:7.8:1), but greater His oxidation. Only low levels of intra- dityrosine cross-links and no inter- dityrosine oligomers were detected under these conditions, suggesting that ascorbate limits Cu²⁺/H₂O₂-induced α-synuclein modification.

Sleep duration, obesity and insulin resistance in a multi-ethnic UK population at high risk of diabetes

AIMS

Investigating the association between sleep duration, obesity, adipokines and insulin resistance (via Leptin:Adiponectin ratio (LAR)), in those at high risk of type 2 diabetes mellitus (T2DM).

METHODS

Adults with impaired glucose regulation (IGR) were included. Fasting bloods for inflammatory biomarkers and glycaemic status, 2-h glucose, anthropometrics, objective physical activity, and self-reported sleep were collected. The average number of hours slept in a 24 h period was categorised as ≤5.5, 6-6.5, 7-7.5, 8-8.5, and ≥9 h. Regression models were fitted with sleep (linear and quadratic) and logistic regression used for IGR and adjusted for age, sex, ethnicity, body mass index, waist circumference and objective physical activity.

RESULTS

2848 participants included (593 with inflammatory marker data). Short sleep and long sleep duration were significantly independently associated with higher body mass index (P < 0.001), body weight (P < 0.01), and waist circumference (P < 0.001). 6-7 h of sleep/24 h is associated with the lowest obesity measures. Fasting insulin and LAR were positively associated with sleep duration. Adiponectin levels were negatively associated with sleep duration.

CONCLUSIONS

These results support the evidence of an association between short and long sleep duration and indices of obesity. We demonstrate an independent relationship between long sleep duration and insulin resistance.

Superoxide radicals react with peptide-derived tryptophan radicals with very high rate constants to give hydroperoxides as major products

Oxidative damage is a common process in many biological systems and proteins are major targets for damage due to their high abundance and very high rate constants for reaction with many oxidants (both radicals and two-electron species). Tryptophan (Trp) residues on peptides and proteins are a major sink for a large range of biological oxidants as these side-chains have low radical reduction potentials. The resulting Trp-derived indolyl radicals (Trp^•) have long lifetimes in some circumstances due to their delocalized structures, and undergo only slow reaction with molecular oxygen, unlike most other biological radicals. In contrast, we have shown previously that Trp^• undergo rapid dimerization. In the current study, we show that Trp^• also undergo very fast reaction with superoxide radicals, O₂^•-, with k 1-2 × 10⁹ M^-1 s^-1. These values do not alter dramatically with peptide structure, but the values of k correlate with overall peptide positive charge, consistent with positive electrostatic interactions. These reactions compete favourably with Trp^• dimerization and O₂ addition, indicating that this may be a major fate in some circumstances. The Trp^• + O₂^•- reactions occur primarily by addition, rather than electron transfer, with this resulting in high yields of Trp-derived hydroperoxides. Subsequent degradation of these species, both stimulated and native decay, gives rise to N-formylkynurenine, kynurenine, alcohols and diols. These data indicate that reaction of O₂^•- with Trp^• should be considered as a major pathway to Trp degradation on peptides and proteins subjected to oxidative damage.

A Survey of the Current Methods Used in the UK to Assess Pituitary Function

A national survey of the current methods used by specialists to evaluate pituitary function in the UK was performed by postal questionnaire. Seventy-three respondents, of whom 89% were consultants and 80% clinical endocrinologists, returned the questionnaire. Fifty per cent routinely used the insulin stress test (IST) to evaluate the hypothalamo-pituitary-adrenal (HPA) axis, while 50% routinely used tetracosactrin stimulation, there being little overlap between the two groups. This represents a significant change in clinical practice since the last survey in 1988. In those who used ACTH stimulation there was almost an equal split into those who administered the tetracosactrin intramuscularly (45%) or intravenously (47%). Furthermore, either the peak or 60 min Cortisol value was used by 71% when interpreting the result of the test, despite the fact that in previous studies only the 30 min Cortisol value has been shown to correlate with the IST result. The IST remains the most frequently used method to assess growth hormone reserve in adult subjects. The thyrotrophin-releasing-hormone and gonadotrophin-releasing-hormone tests are still used routinely by approximately a quarter of clinicians. These results provide data that could be used to develop guide-lines for the use of tests to investigate pituitary function.

The impact of neighbourhood walkability on the effectiveness of a structured education programme to increase objectively measured walking

Background

Incorporating physical activity into daily activities is key for the effectiveness of lifestyle education interventions aimed at improving health outcomes; however, consideration of the environmental context in which individuals live is not always made. Walkability is a characteristic of the physical environment, and may be a potential facilitator to changing physical activity levels.

Methods

Using data collected during the Walking Away from Diabetes randomized controlled trial, we examined the association between the walkability of the home neighbourhood and physical activity of participants. We also determined whether home neighbourhood walkability of participants was associated with the intervention effect of the education programme.

Results

Data from 706 participants were available for analysis. Neighbourhood walkability was not significantly associated with any of the physical activity measures at baseline, or at 12, 24 or 36 months following the intervention (P > 0.05 for all). There was no association between walkability and change in purposeful steps/day from baseline to 36 months in the usual care or intervention arm; 25.77 (-99.04, 150.58) and 42.97 (-327.63, 413.45), respectively.

Conclusion

Neighbourhood walkability appeared to have no association with objectively measured physical activity in this population. Furthermore, the walkability of participant's neighbourhood did not influence the effectiveness of a lifestyle programme.

Achieving the composite endpoint of HbA1c, body weight, and systolic blood pressure reduction with canagliflozin in patients with type 2 diabetes

OBJECTIVE

In addition to achieving glycemic control, weight loss and blood pressure (BP) reduction are important components of type 2 diabetes mellitus (T2DM) management, as many patients with T2DM are overweight/obese and/or have hypertension. Canagliflozin, an SGLT2 inhibitor, has demonstrated improvements in HbA1c, body weight (BW), and systolic BP across a broad range of patients with T2DM. This analysis evaluated achievement of composite endpoints of HbA1c, BW, and systolic BP targets with canagliflozin versus placebo.

METHODS

This post hoc analysis evaluated the proportion of T2DM patients achieving the composite endpoint of HbA1c reduction ≥0.5%, BW reduction ≥3%, and systolic BP reduction ≥4mmHg with canagliflozin 100 and 300mg compared with placebo using pooled data from four 26-week, phase 3 studies (N = 2313; NCT01081834, NCT01106677, NCT01106625, NCT01106690). The proportion of patients achieving the composite endpoint of HbA1c <7.0%, BW reduction ≥3%, and BP <130/80 mmHg was also evaluated.

RESULTS

At week 26, greater proportions of patients met individual HbA1c, BW, and systolic BP targets with canagliflozin versus placebo. A greater proportion of patients treated with canagliflozin 100 or 300 mg versus placebo also achieved the composite endpoint of HbA1c reduction ≥0.5%, BW reduction ≥3%, and systolic BP reduction ≥4 mmHg at week 26 (21.1%, 25.3%, and 5.7%, respectively; odds ratios [95% CI] of 4.5 [3.1, 6.5] and 5.6 [3.8, 8.2]). A greater proportion of patients also achieved the composite endpoint of HbA1c <7.0%, BW reduction ≥3%, and BP <130/80 mmHg with canagliflozin 100 and 300 mg versus placebo (14.7%, 20.9%, and 3.3%, respectively; odds ratios [95% CI] of 5.2 [3.2, 8.4] and 8.4 [5.2, 13.5]). Canagliflozin was generally well tolerated, with a safety profile similar to that seen in other phase 3 studies.

CONCLUSIONS

Patients with T2DM were more likely to achieve clinically important reductions in HbA1c, BW, and systolic BP with canagliflozin versus placebo.

Exposure of tropoelastin to peroxynitrous acid gives high yields of nitrated tyrosine residues, di-tyrosine cross-links and altered protein structure and function

Elastin is an abundant extracellular matrix protein in elastic tissues, including the lungs, skin and arteries, and comprises 30-57% of the aorta by dry mass. The monomeric precursor, tropoelastin (TE), undergoes complex processing during elastogenesis to form mature elastic fibres. Peroxynitrous acid (ONOOH), a potent oxidising and nitrating agent, is formed in vivo from superoxide and nitric oxide radicals. Considerable evidence supports ONOOH formation in the inflamed artery wall, and a role for this species in the development of human atherosclerotic lesions, with ONOOH-damaged extracellular matrix implicated in lesion rupture. We demonstrate that TE is highly sensitive to ONOOH, with this resulting in extensive dimerization, fragmentation and nitration of Tyr residues to give 3-nitrotyrosine (3-nitroTyr). This occurs with equimolar or greater levels of oxidant and increases in a dose-dependent manner. Quantification of Tyr loss and 3-nitroTyr formation indicates extensive Tyr modification with up to two modified Tyr per protein molecule, and up to 8% conversion of initial ONOOH to 3-nitroTyr. These effects were modulated by bicarbonate, an alternative target for ONOOH. Inter- and intra-protein di-tyrosine cross-links have been characterized by mass spectrometry. Examination of human atherosclerotic lesions shows colocalization of 3-nitroTyr with elastin epitopes, consistent with TE or elastin modification in vivo, and also an association of 3-nitroTyr containing proteins and elastin with lipid deposits. These data suggest that exposure of TE to ONOOH gives marked chemical and structural changes to TE and altered matrix assembly, and that such damage accumulates in human arterial tissue during the development of atherosclerosis.

Sleep disturbances in women with polycystic ovary syndrome: prevalence, pathophysiology, impact and management strategies

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder affecting the reproductive, metabolic and psychological health of women. Clinic-based studies indicate that sleep disturbances and disorders including obstructive sleep apnea and excessive daytime sleepiness occur more frequently among women with PCOS compared to comparison groups without the syndrome. Evidence from the few available population-based studies is supportive. Women with PCOS tend to be overweight/obese, but this only partly accounts for their sleep problems as associations are generally upheld after adjustment for body mass index; sleep problems also occur in women with PCOS of normal weight. There are several, possibly bidirectional, pathways through which PCOS is associated with sleep disturbances. The pathophysiology of PCOS involves hyperandrogenemia, a form of insulin resistance unique to affected women, and possible changes in cortisol and melatonin secretion, arguably reflecting altered hypothalamic-pituitary-adrenal function. Psychological and behavioral pathways are also likely to play a role, as anxiety and depression, smoking, alcohol use and lack of physical activity are also common among women with PCOS, partly in response to the distressing symptoms they experience. The specific impact of sleep disturbances on the health of women with PCOS is not yet clear; however, both PCOS and sleep disturbances are associated with deterioration in cardiometabolic health in the longer term and increased risk of type 2 diabetes. Both immediate quality of life and longer-term health of women with PCOS are likely to benefit from diagnosis and management of sleep disorders as part of interdisciplinary health care.

Synthesis and antioxidant capacity of novel stable 5-tellurofuranose derivatives

Novel stable tellurium-containing carbohydrates are prepared; these react very rapidly with two-electron oxidants and show promise as protective agents.

Role of Mitochondrial Reactive Oxygen Species in the Activation of Cellular Signals, Molecules, and Function

Mitochondria are a major source of intracellular energy and reactive oxygen species in cells, but are also increasingly being recognized as a controller of cell death. Here, we review evidence of signal transduction control by mitochondrial superoxide generation via the nuclear factor-κB (NF-κB) and GATA signaling pathways. We have also reviewed the effects of ROS on the activation of MMP and HIF. There is significant evidence to support the hypothesis that mitochondrial superoxide can initiate signaling pathways following transport into the cytosol. In this study, we provide evidence of TATA signal transductions by mitochondrial superoxide. Oxidative phosphorylation via the electron transfer chain, glycolysis, and generation of superoxide from mitochondria could be important factors in regulating signal transduction, cellular homeostasis, and cell death.

Formation and detection of oxidant-generated tryptophan dimers in peptides and proteins

Free radicals are produced during physiological processes including metabolism and the immune response, as well as on exposure to multiple external stimuli. Many radicals react rapidly with proteins resulting in side-chain modification, backbone fragmentation, aggregation, and changes in structure and function. Due to its low oxidation potential, the indole ring of tryptophan (Trp) is a major target, with this resulting in the formation of indolyl radicals (Trp^•). These undergo multiple reactions including ring opening and dimerization which can result in protein aggregation. The factors that govern Trp^• dimerization, the rate constants for these reactions and the exact nature of the products are not fully elucidated. In this study, second-order rate constants were determined for Trp^• dimerization in Trp-containing peptides to be 2-6 × 10⁸M^-1s^-1 by pulse radiolysis. Peptide charge and molecular mass correlated negatively with these rate constants. Exposure of Trp-containing peptides to steady-state radiolysis in the presence of NaN₃ resulted in consumption of the parent peptide, and detection by LC-MS of up to 4 different isomeric Trp-Trp cross-links. Similar species were detected with other oxidants, including CO₃^•- (from the HCO₃^- -dependent peroxidase activity of bovine superoxide dismutase) and peroxynitrous acid (ONOOH) in the presence or absence of HCO₃^-. Trp-Trp species were also isolated and detected after alkaline hydrolysis of the oxidized peptides and proteins. These studies demonstrate that Trp^• formed on peptides and proteins undergo rapid recombination reactions to form Trp-Trp cross-linked species. These products may serve as markers of radical-mediated protein damage, and represent an additional pathway to protein aggregation in cellular dysfunction and disease.

Selenium-containing indolyl compounds: Kinetics of reaction with inflammation-associated oxidants and protective effect against oxidation of extracellular matrix proteins

Activated white blood cells generate multiple oxidants in response to invading pathogens. Thus, hypochlorous acid (HOCl) is generated via the reaction of myeloperoxidase (from neutrophils and monocytes) with hydrogen peroxide, and peroxynitrous acid (ONOOH), a potent oxidizing and nitrating agent is formed from superoxide radicals and nitric oxide, generated by stimulated macrophages. Excessive or misplaced production of these oxidants has been linked to multiple human pathologies, including cardiovascular disease. Atherosclerosis is characterized by chronic inflammation and the presence of oxidized materials, including extracellular matrix (ECM) proteins, within the artery wall. Here we investigated the potential of selenium-containing indoles to afford protection against these oxidants, by determining rate constants (k) for their reaction, and quantifying the extent of damage on isolated ECM proteins and ECM generated by human coronary artery endothelial cells (HCAECs). The novel selenocompounds examined react with HOCl with k 0.2-1.0 × 10⁸M^-1s^-1, and ONOOH with k 4.5-8.6 - × 10⁵M^-1s^-1. Reaction with H₂O₂ is considerably slower (k < 0.25M^-1s^-1). The selenocompound 2-phenyl-3-(phenylselanyl)imidazo[1,2-a]pyridine provided protection to human serum albumin (HSA) against HOCl-mediated damage (as assessed by SDS-PAGE) and damage to isolated matrix proteins induced by ONOOH, with a concomitant decrease in the levels of the biomarker 3-nitrotyrosine. Structural damage and generation of 3-nitroTyr on HCAEC-ECM were also reduced. These data demonstrate that the novel selenium-containing compounds show high reactivity with oxidants and may modulate oxidative and nitrosative damage at sites of inflammation, contributing to a reduction in tissue dysfunction and atherogenesis.

Effect of Oxidation and Protein Unfolding on Cross-Linking of β-Lactoglobulin and α-Lactalbumin

Oxidation and heat treatment can initiate changes in the amino acid composition, structure, solubility, hydrophobicity, conformation, function, and susceptibility to proteolysis of proteins. These can result in adverse consequences for mammals, plants, foodstuffs, and pharmaceuticals. This study investigated whether and how individual or combined treatment with heat, a commonly encountered factor in industrial processing, and H₂O₂ alters the structure and composition of two major milk whey proteins, α-lactalbumin and β-lactoglobulin, and mixtures of these. Thermal treatment induced reducible cross-links in isolated β-lactoglobulin, but not isolated α-lactalbumin under the conditions employed. Cross-linking occurred at lower temperatures and to a greater extent in the presence of low concentrations of H₂O₂. H₂O₂ did not induce cross-linking in the absence of heat. Mixtures of α-lactalbumin and β-lactoglobulin showed similar behavior, except that mixed α-lactalbumin-β-lactoglobulin dimers were detected. Cross-linking was associated with formation of sulfenic acids (RS-OH species), oxidation of methionine residues, cleavage of disulfide bonds in α-lactalbumin, altered conformation of disulfide bonds in β-lactoglobulin, alterations in the fluorescence intensity and maximum emission wavelength of endogenous tryptophan residues, and binding of the hydrophobic probe 8-anilinonaphthalenesulfonate. These data are consistent with increased unfolding and subsequent aggregation of the protein, with these changes being maximized in the presence of both heat and H₂O₂. The enhanced aggregation detected with H₂O₂ is consistent with additional pathways to aggregation above that induced by heat alone. These mechanistic insights provide potential strategies for modulating the extent and nature of protein modification induced by thermal and oxidant treatment.

The peroxyl radical-induced oxidation of Escherichia coli FtsZ and its single tryptophan mutant (Y222W) modifies specific side-chains, generates protein cross-links and affects biological function

FtsZ (filamenting temperature-sensitive mutant Z) is a key protein in bacteria cell division. The wild-type Escherichia coli FtsZ sequence (FtsZwt) contains three tyrosine (Tyr, Y) and sixteen methionine (Met, M) residues. The Tyr at position 222 is a key residue for FtsZ polymerization. Mutation of this residue to tryptophan (Trp, W; mutant Y222W) inhibits GTPase activity resulting in an extended time in the polymerized state compared to FtsZwt. Protein oxidation has been highlighted as a determinant process for bacteria resistance and consequently oxidation of FtsZwt and the Y222W mutant, by peroxyl radicals (ROO•) generated from AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride) was studied. The non-oxidized proteins showed differences in their polymerization behavior, with this favored by the presence of Trp at position 222. AAPH-treatment of the proteins inhibited polymerization. Protein integrity studies using SDS-PAGE revealed the presence of both monomers and oligomers (dimers, trimers and high mass material) on oxidation. Western blotting indicated the presence of significant levels of protein carbonyls. Amino acid analysis showed that Tyr, Trp (in the Y222W mutant), and Met were consumed by ROO•. Quantification of the number of moles of amino acid consumed per mole of ROO• shows that most of the initial oxidant can be accounted for at low radical fluxes, with Met being a major target. Western blotting provided evidence for di-tyrosine cross-links in the dimeric and trimeric proteins, confirming that oxidation of Tyr residues, at positions 339 and/or 371, are critical to ROO•-mediated crosslinking of both the FtsZwt and Y222W mutant protein. These findings are in agreement with di-tyrosine, N-formyl kynurenine, and kynurenine quantification assessed by UPLC, and with LC-MS data obtained for AAPH-treated protein samples.

The prevalence of diabetes-specific emotional distress in people with Type 2 diabetes: a systematic review and meta-analysis

AIMS

Psychological comorbidity, such as depression and/or diabetes-specific emotional distress (diabetes distress), is widespread in people with Type 2 diabetes and is associated with poorer treatment outcomes. Although extensive research into the prevalence of depression has been conducted, the same attention has not been given to diabetes distress. The aim of this systematic review was to determine the overall prevalence of diabetes distress in people with Type 2 diabetes.

METHODS

Seven databases were searched to identify potentially relevant studies; eligible studies (adult population aged > 18 years with Type 2 diabetes and an outcome measure of diabetes distress) were selected and appraised independently by two reviewers. Multiple fixed- and random-effects meta-analyses were performed to synthesize the data; with primary analyses to determine the overall prevalence of diabetes distress in people with Type 2 diabetes, and secondary meta-analyses and meta-regression to explore the prevalence across different variables.

RESULTS

Fifty-five studies (n = 36 998) were included in the meta-analysis and demonstrated an overall prevalence of 36% for diabetes distress in people with Type 2 diabetes. Prevalence of diabetes distress was significantly higher in samples with a higher prevalence of comorbid depressive symptoms and a female sample majority.

CONCLUSIONS

Diabetes distress is a prominent issue in people with Type 2 diabetes that is associated with female gender and comorbid depressive symptoms. It is important to consider the relationship between diabetes distress and depression, and the significant overlap between conditions. Further work is needed to explore psychological comorbidity in Type 2 diabetes to better understand how best to identify and appropriately treat individuals.

Peroxyl radical- and photo-oxidation of glucose 6-phosphate dehydrogenase generates cross-links and functional changes via oxidation of tyrosine and tryptophan residues

Protein oxidation is a frequent event as a result of the high abundance of proteins in biological samples and the multiple processes that generate oxidants. The reactions that occur are complex and poorly understood, but can generate major structural and functional changes on proteins. Current data indicate that pathophysiological processes and multiple human diseases are associated with the accumulation of damaged proteins. In this study we investigated the mechanisms and consequences of exposure of the key metabolic enzyme glucose-6-phosphate dehydrogenase (G6PDH) to peroxyl radicals (ROO^•) and singlet oxygen (¹O₂), with particular emphasis on the role of Trp and Tyr residues in protein cross-linking and fragmentation. Cross-links and high molecular mass aggregates were detected by SDS-PAGE and Western blotting using specific antibodies. Amino acid analysis has provided evidence for Trp and Tyr consumption and formation of oxygenated products (diols, peroxides, N-formylkynurenine, kynurenine) from Trp, and di-tyrosine (from Tyr). Mass spectrometric data obtained after trypsin-digestion in the presence of H₂¹⁶O and H₂¹⁸O, has allowed the mapping of specific cross-linked residues and their locations. These data indicate that specific Tyr-Trp and di-Tyr cross-links are formed from residues that are proximal and surface-accessible, and that the extent of Trp oxidation varies markedly between sites. Limited modification at other residues is also detected. These data indicate that Trp and Tyr residues are readily modified by ROO^• and ¹O₂ with this giving products that impact significantly on protein structure and function. The formation of such cross-links may help rationalize the accumulation of damaged proteins in vivo.

External national validation of the Leicester Self-Assessment score for Type 2 diabetes using data from the English Longitudinal Study of Ageing

AIMS

To validate the Leicester Self-Assessment score using a representative English dataset for detecting prevalent non-diabetic hyperglycaemia or undiagnosed Type 2 diabetes (defined as HbA_1c ≥6.0%) and for identifying those who may go on to develop Type 2 diabetes within 10 years.

METHODS

Data were taken from the English Longitudinal Study of Ageing, a nationally representative dataset of people aged ≥50 years. The area under the receiver-operator curve and performance metrics for the score at the recommended score threshold (≥16), were calculated for the outcomes of HbA_1c ≥42 mmol/mol (6.0%) at baseline and self-reported Type 2 diabetes within 10 years in those aged 50-75 years at baseline.

RESULTS

A total of 3203 individuals had a baseline HbA_1c measurement, of whom 247 (7.7%) had an HbA_1c concentration ≥42 mmol/mol (6.0%). The area under the receiver-operator curve was 69.4% (95% CI 66.0-72.9) for baseline HbA_1c ≥42 mmol/mol. A total of 3550 individuals had diabetes status recorded at 10 years, of whom 324 (9.1%) were diagnosed with Type 2 diabetes within this time; the area under the receiver-operator curve for this outcome was 74.9% (95% CI 72.4-77.5). The score threshold of ≥16 had a sensitivity of 89.2% (95% CI 85.3-92.4) and a specificity of 42.3% (95% CI 40.5-44.0) for Type 2 diabetes within 10 years.

CONCLUSIONS

The Leicester Self-Assessment score is validated for use across England to identify people with non-diabetic hyperglycaemia or undiagnosed Type 2 diabetes. Those with a high score are at high risk of developing diabetes in the future.

Unrestricted Mass Spectrometric Data Analysis for Identification, Localization, and Quantification of Oxidative Protein Modifications

Oxidation generates multiple diverse post-translational modifications resulting in changes in protein structure and function associated with a wide range of diseases. Of these modifications, carbonylations have often been used as hallmarks of oxidative damage. However, accumulating evidence supports the hypothesis that other oxidation products may be quantitatively more important under physiological conditions. To address this issue, we have developed a holistic mass spectrometry-based approach for the simultaneous identification, localization, and quantification of a broad range of oxidative modifications based on so-called "dependent peptides". The strategy involves unrestricted database searches with rigorous filtering focusing on oxidative modifications. The approach was applied to bovine serum albumin and human serum proteins subjected to metal ion-catalyzed oxidation, resulting in the identification of a wide range of different oxidative modifications. The most common modification in the oxidized samples is hydroxylation, but carbonylation, decarboxylation, and dihydroxylation are also abundant, while carbonylation showed the largest increase in abundance relative to nonoxidized samples. Site-specific localization of modified residues reveals several "oxidation hotspots" showing high levels of modification occupancy, including specific histidine, tryptophan, methionine, glutamate, and aspartate residues. The majority of the modifications, however, occur at low occupancy levels on a diversity of side chains.

Older people with Type 2 diabetes, including those with chronic kidney disease or dementia, are commonly overtreated with sulfonylurea or insulin therapies

AIM

To evaluate potential overtreatment with sulfonylurea and insulin therapies amongst older people with Type 2 diabetes, including those with chronic kidney disease or dementia.

METHODS

Using the ECLIPSE Live software tool, we developed a search to examine data on older people (age ≥ 70 years) with Type 2 diabetes, who were prescribed sulfonylurea or insulin therapies over the previous 90 days. Sixteen Norfolk general practices participated, representing a population of 24 661 older people, including 3862 (15.7%) with Type 2 diabetes. Of these, 1379 (35.7%) people were prescribed sulfonylurea or insulin therapies. Data extracted included age, sex, last recorded HbA_1c value, renal function and dementia codes.

RESULTS

The median age of the study cohort was 78 years. A total of 644 people (47.8%) had chronic kidney disease (estimated GFR < 60 mL/min/1.73m² ) and 60 people (4.35%) had dementia. The median (interquartile range) HbA_1c concentration for the entire cohort was 58 (51-69) mmol/mol [7.5 (6.8-8.5)%], with no difference in median HbA_1c between those with or without either chronic kidney disease or dementia. In total, 400 older people (29.9%) had an HbA_1c concentration < 53 mmol/mol (7%), of whom 162 (12.1%) had HbA_1c < 48 mmol/mol (6.5%). Stratified by prescription for sulfonylurea, insulin or combined insulin and sulfonylurea therapies, 282 (35.2%), 93 (24.2%) and 25 people (16.3%), respectively, had HbA_1c < 53 mmol/mol (7.0%). Treatment to an HbA_1c target of < 53 mmol/mol (7.0%) was as prevalent in those with chronic kidney disease or dementia as in those without.

CONCLUSION

In the present cohort of older people with Type 2 diabetes prescribed sulfonylurea or insulin therapies, overtreatment was common, even in the presence of comorbidities known to increase hypoglycaemia risk.

Continuous glucose monitoring detected hypoglycaemia in the Treating to Target in Type 2 Diabetes Trial (4-T)

AIMS

Hypoglycaemia is a significant risk in insulin treated type 2 diabetes and has been associated with future risk of cardiovascular events. We compared the frequency of low-glucose events using continuous glucose monitoring (CGM) with that of self-reported hypoglycemic events at the end of the first and third years of the Treating to Target in Type 2 Diabetes Trial (4-T), which compared biphasic, prandial and basal insulin regimens added to sulfonylurea and metformin.

METHODS

CGM using a Medtronic Gold system was performed in a subgroup of 4-T participants. CGM detected low-glucose events were defined at thresholds of ≤3.0 (CGM3.0) and ≤2.2 (CGM2.2) mmol/l.

RESULTS

Of the 110 participants, 106 and 70 had CGM analysable data at the end of years 1 and 3 respectively. In both years, the frequency of CGM detected low glucose events was several fold higher than that of self-reported hypoglycaemia (symptoms with blood glucose less than 3.1mmol/l [<56mg/dl]). At the end of the first year, CGM3.0 and CGM2.2 mean (95%CI) event frequencies, expressed at events per participant per year, were 120 (85, 155) and 41 (21, 61) compared with 17 (8, 29) self-reported events during CGM, each p=0.001. The disparity at the end of the third year was similar.

CONCLUSIONS

These data demonstrate the likely under-reporting of hypoglycaemia and of potential hypoglycaemia unawareness in clinical trials. The clinical implications of these findings need to be explored further (ISRCTN No ISRCTN51125379).

Adult Orbital and Adnexal Xanthogranulomatous Disease

PURPOSE

Adult xanthogranulomatous disease of the orbit and ocular adnexa is a rare disease that can cause serious morbidity and mortality. Ophthalmologists are commonly the first clinicians to come in contact with affected patients and an understanding of the clinical features is essential.

DESIGN

We present a retrospective case series of patients seen in the oculoplastic unit of a large tertiary referral hospital over a 20-year period.

METHODS

The clinical files of 7 patients with adult xanthogranulomatous disease of the orbit and ocular adnexa were reviewed. Clinical, radiological, histopathological, and immunohistochemical findings were examined.

RESULTS

Periocular clinical features included cutaneous xanthogranulomatous lesions, decreased visual acuity, proptosis, diplopia, skin ulceration, cicatricial ectropion, and mechanical ptosis. Systemic features included adult-onset asthma, disseminated xanthogranulomatous lesions with long bone involvement, and hematological disturbances such as monoclonal gammopathy and lymphoplasmacytic lymphoma. Lipid-laden macrophages and Touton multinucleated giant cells were histological hallmarks in all subtypes. Most lesions were strongly CD8 positive on immunohistochemistry. Radiologically, the lesions were diffuse and infiltrative in nature. Various treatments were employed with varying success including surgical excision, systemic and intralesional corticosteroids, other immunosuppressants, and systemic chemotherapy.

CONCLUSIONS

Adult xanthogranulomatous disease of the orbit and ocular adnexa, although rare, may be sight or life threatening. Recognition by the ophthalmologist is critical as periocular features often constitute the initial presentation.

Acute effects of exercise on appetite, ad libitum energy intake and appetite-regulatory hormones in lean and overweight/obese men and women

BACKGROUND

Acute exercise does not elicit compensatory changes in appetite parameters in lean individuals; however, less is known about responses in overweight individuals. This study compared the acute effects of moderate-intensity exercise on appetite, energy intake and appetite-regulatory hormones in lean and overweight/obese individuals.

METHODS

Forty-seven healthy lean (n=22, 11 females; mean (s.d.) 37.5 (15.2) years; 22.4 (1.5) kg m^-2) and overweight/obese (n=25, 11 females; 45.0 (12.4) years, 29.2 (2.9) kg m^-2) individuals completed two, 8 h trials (exercise and control). In the exercise trial, participants completed 60 min treadmill exercise (59 (4)% peak oxygen uptake) at 0-1 h and rested thereafter while participants rested throughout the control trial. Appetite ratings and concentrations of acylated ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured at predetermined intervals. Standardised meals were consumed at 1.5 and 4 h and an ad libitum buffet meal was provided at 7 h.

RESULTS

Exercise suppressed appetite (95% confidence interval (CI) -3.1 to -0.5 mm, P=0.01), and elevated delta PYY (95% CI 10 to 17 pg ml^-1, P<0.001) and GLP-1 (95% CI 7 to 10 pmol l^-1, P<0.001) concentrations. Delta acylated ghrelin concentrations (95% CI -5 to 3 pg ml^-1, P=0.76) and ad libitum energy intake (95% CI -391 to 346 kJ, P=0.90) were similar between trials. Subjective and hormonal appetite parameters and ad libitum energy intake were similar between lean and overweight/obese individuals (P⩾0.27). The exercise-induced elevation in delta GLP-1 was greater in overweight/obese individuals (trial-by-group interaction P=0.01), whereas lean individuals exhibited a greater exercise-induced increase in delta PYY (trial-by-group interaction P<0.001).

CONCLUSIONS

Acute moderate-intensity exercise transiently suppressed appetite and increased PYY and GLP-1 in the hours after exercise without stimulating compensatory changes in appetite in lean or overweight/obese individuals. These findings underscore the ability of exercise to induce a short-term energy deficit without any compensatory effects on appetite regardless of weight status.

Deficiencies in postgraduate training for healthcare professionals who provide diabetes education and support: results from the Diabetes Attitudes, Wishes and Needs (DAWN2) study

AIMS

To consider the global provision of self-management diabetes education and training for healthcare professionals using data from the second Diabetes Attitudes, Wishes and Needs (DAWN2) study.

METHODS

A total of 4785 healthcare professionals caring for people with diabetes were surveyed in 17 countries to assess diabetes healthcare provision, self-management support and training.

RESULTS

Of the healthcare professionals surveyed, 33.5% received formal postgraduate training in self-management (19.3-51.4% across countries) and 62.9% received training for medical management of diabetes (47.6-70.6% variation). Training in psychological management was low (19.1%), ranging from 3.6 to 36.5%, while 20.4% (a range of 3.6-36.4% across countries) had received no postgraduate training. Overall, the greatest training need was in the management of psychological aspects of diabetes (59.5%). For some, training in a domain was positively associated with a perceived need for further training. Communication skills, for example, listening (76.9%) and encouraging questions (76.1%), were the skills most widely used. Discussion of emotional issues was limited; 31-60% of healthcare professionals across the different countries reported that this only occurred if initiated by patients. Approximately two-thirds of participants reported a need for major improvements in emotional/psychological support, but few had received training in this area, with consistent findings across professional affiliations.

CONCLUSIONS

The present study shows that healthcare professionals report being insufficiently equipped to provide diabetes self-management education, including emotional and psychological aspects of diabetes, and many are not receiving postgraduate training in any part (including medical care) of the management of diabetes. It is paramount that those responsible for the continuing professional development of healthcare professionals address this skills gap.

Effects of Canagliflozin on Cardiovascular Biomarkers in Older Adults With Type 2 Diabetes

BACKGROUND

Sodium glucose co-transporter 2 inhibitors may reduce cardiovascular and heart failure risk in patients with type 2 diabetes mellitus (T2DM).

OBJECTIVES

The goal of this study was to examine the effects of canagliflozin on cardiovascular biomarkers in older patients with T2DM.

METHODS

In 666 T2DM patients randomized to receive canagliflozin 100 or 300 mg or placebo, the study assessed the median percent change in serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin I (hsTnI), soluble (s)ST2, and galectin-3 from baseline to 26, 52, and 104 weeks.

RESULTS

Both serum NT-proBNP and serum hsTnI levels increased in placebo recipients, but they remained largely unchanged in those randomized to canagliflozin. Hodges-Lehmann estimates of the difference in median percent change between pooled canagliflozin and placebo were -15.0%, -16.1%, and -26.8% for NT-proBNP, and -8.3%, -11.9%, and -10.0% for hsTnI at weeks 26, 52, and 104, respectively (all p < 0.05). Serum sST2 was unchanged with canagliflozin and placebo over 104 weeks. Serum galectin-3 modestly increased from baseline with canagliflozin versus placebo, with significant differences observed at 26 and 52 weeks but not at 104 weeks. These results remained unchanged when only patients with complete samples were assessed.

CONCLUSIONS

Compared with placebo, treatment with canagliflozin delayed the rise in serum NT-proBNP and hsTnI for over 2 years in older T2DM patients. These cardiac biomarker data provide support for the beneficial cardiovascular effect of sodium glucose co-transporter 2 inhibitors in T2DM. (A Safety and Efficacy Study of Canagliflozin in Older Patients [55 to 80 Years of Age] With Type 2 Diabetes Mellitus; NCT01106651).

The immunoproteasome is induced by cytokines and regulates apoptosis in human islets

In addition to degrading misfolded and damaged proteins, the proteasome regulates the fate of cells in response to stress. The role of the proteasome in pro-inflammatory cytokine-induced human beta-cell apoptosis is unknown. Using INS-1, INS-1E and human islets exposed to combinations of IFNγ, IL-1β and TNFα with or without addition of small molecules, we assessed the role of the immunoproteasome in pancreatic beta-cell demise. Here, we show that cytokines induce the expression and activity of the immuno-proteasome in INS-1E cells and human islets. Cytokine-induced expression of immuno-proteasome subunits, but not activity, depended upon histone deacetylase 3 activation. Inhibition of JAK1/STAT1 signaling did not affect proteasomal activity. Inhibition of the immuno-proteasome subunit PSMB8 aggravated cytokine-induced human beta-cell apoptosis while reducing intracellular levels of oxidized proteins in INS-1 cells. While cytokines increased total cellular NFκB subunit P50 and P52 levels and reduced the cytosolic NFκB subunit P65 and IκB levels, these effects were unaffected by PSMB8 inhibition. We conclude that beta cells upregulate immuno-proteasome expression and activity in response to IFNγ, likely as a protective response to confine inflammatory signaling.

Walking Away from Type 2 diabetes: a cluster randomized controlled trial

AIMS

This study aimed to investigate whether an established behavioural intervention, Walking Away from Type 2 Diabetes, is effective at promoting and sustaining increased walking activity when delivered within primary care.

METHODS

Cluster randomized controlled trial involving 10 general practices recruited from Leicestershire, UK, in 2009-2010. Eight hundred and eight (36% female) individuals with a high risk of Type 2 diabetes mellitus, identified through a validated risk score, were included. Participants in five practices were randomized to Walking Away from Type 2 Diabetes, a pragmatic 3-h group-based structured education programme incorporating pedometer use with annual follow-on refresher sessions. The primary outcome was accelerometer assessed ambulatory activity (steps/day) at 12 months. Longer term maintenance was assessed at 24 and 36 months. Results were analysed using generalized estimating equation models, accounting for clustering.

RESULTS

Complete accelerometer data for the primary outcome were available for 571 (71%) participants. Increases in ambulatory activity of 411 steps/day [95% confidence interval (CI): 117, 704] and self-reported vigorous-intensity physical activity of 218 metabolic equivalent min/week (95% CI: 6, 425) at 12 months were observed in the intervention group compared with control; differences between groups were not sustained at 36 months. No differences between groups were observed for markers of cardiometabolic health. Replacing missing data with multiple imputation did not affect the results.

CONCLUSIONS

A pragmatic low-resource group-based structured education programme with pedometer use resulted in modest increases in ambulatory activity compared with control conditions after 12 months when implemented within a primary care setting to those at high risk of Type 2 diabetes mellitus; however, the results were not maintained over 36 months.

Cardiovascular risk factors and incident albuminuria in screen-detected type 2 diabetes

BACKGROUND

It is unclear whether cardiovascular risk factor modification influences the development of renal disease in people with type 2 diabetes identified through screening. We determined predictors of albuminuria 5 years after a diagnosis of screen-detected diabetes within the ADDITION-Europe study, a pragmatic cardiovascular outcome trial of multifactorial cardiovascular risk management.

METHODS

In 1826 participants with newly diagnosed, screen-detected diabetes without albuminuria, we explored associations between risk of new albuminuria (≥2.5 mg mmol-1 for males and ≥3.5 mg mmol-1 for females) and (1) baseline cardio-metabolic risk factors and (2) changes from baseline to 1 year in systolic blood pressure (ΔSBP) and glycated haemoglobin (ΔHbA1c ) using logistic regression.

RESULTS

Albuminuria developed in 268 (15%) participants; baseline body mass index and active smoking were independently associated with new onset albuminuria in 5 years after detection of diabetes. In a model adjusted for age, gender, baseline HbA1c and blood pressure, a 1% decrease in HbA1c and 5-mm Hg decrease in SBP during the first year were independently associated with lower risks of albuminuria (odds ratio), 95% confidence interval: 0.76, 0.62 to 0.91 and 0.94, 0.88 to 1.01, respectively. Further adjustment did not materially change these estimates. There was no interaction between ΔSBP and ΔHbA1c in relation to albuminuria risk, suggesting likely additive effects on renal microvascular disease.

CONCLUSIONS

Baseline measurements and changes in HbA1c and SBP a year after diagnosis of diabetes through screening independently associate with new onset albuminuria 4 years later. Established multifactorial treatment for diabetes applies to cases identified through screening.

Catalytic oxidant scavenging by selenium-containing compounds: Reduction of selenoxides and N-chloramines by thiols and redox enzymes

Myeloperoxidase produces strong oxidants during the immune response to destroy invading pathogens. However, these oxidants can also cause tissue damage, which contributes to the development of numerous inflammatory diseases. Selenium containing compounds, including selenomethionine (SeMet) and 1,4-anhydro-5-seleno-D-talitol (SeTal), react rapidly with different MPO-derived oxidants to form the respective selenoxides (SeMetO and SeTalO). This study investigates the susceptibility of these selenoxides to undergo reduction back to the parent compounds by intracellular reducing systems, including glutathione (GSH) and the glutathione reductase and thioredoxin reductase systems. GSH is shown to reduce SeMetO and SeTalO, with consequent formation of GSSG with apparent second order rate constants, k₂, in the range 10³–10⁴ M⁻¹ s⁻¹. Glutathione reductase reduces both SeMetO and SeTalO at the expense of NADPH via formation of GSSG, whereas thioredoxin reductase acts only on SeMetO. The presence of SeMet and SeTal also increased the rate at which NADPH was consumed by the glutathione reductase system in the presence of N-chloramines. In contrast, the presence of SeMet and SeTal reduced the rate of NADPH consumption by the thioredoxin reductase system after addition of N-chloramines, consistent with the rapid formation of selenoxides, but only slow reduction by thioredoxin reductase. These results support a potential role of seleno compounds to act as catalytic scavengers of MPO-derived oxidants, particularly in the presence of glutathione reductase and NADPH, assuming that sufficient plasma levels of the parent selenoether can be achieved in vivo following supplementation.

•

Selenoxides react with thiols including GSH by a two-step mechanism.

•

The reaction is proposed to occur via a selenosulfide intermediate.

•

The thioredoxin reductase system recycles selenomethionine selenoxide.

•

The glutathione reductase system reduces both N-chloramines and selenoxides.

•

Selenoxides can increase the reduction of N-chloramines by antioxidant systems.

Evaluating the impact of an enhanced primary care diabetes service on diabetes outcomes: A before-after study

Diabetes is an ambulatory care-sensitive condition and a high quality primary care or risk factor control can lead to a decrease in the risk of non-elective hospitalisations while ensuring continuity of care with usual primary care teams.

AIMS AND METHODS

In this before and after study, eight primary care practices providing a newer enhanced diabetes model of care in Leicester UK, were compared with matched neighbouring practices with comparable demographic features providing a more expensive integrated specialist-community care diabetes service. The primary outcome at twelve months was to demonstrate equivalence in non-elective bed days. The enhanced practices had primary care physicians and nurses with an interest in diabetes who attended monthly diabetes education meetings and provided care plans and audits. The control practices provided an integrated primary-specialist care service.

RESULTS

The difference between the mean change in the non-elective bed days from baseline and at follow up in core and enhanced practices was not statistically significant (mean=2.20 per 100 patients, 95% CI=-0.92 to 5.31 per 100 patients, p=0.14). The analogous change for first outpatients' attendance were 0.23 per 100 patients (95% CI=-0.47 to 0.52 per 100 patients p=0.92) and for diabetes related complications admissions was 0.30 per 100 patients (95% CI=-0.85 to 1.45 per 100 patients p=0.55).

CONCLUSION

A model of enhanced primary care based diabetes care appears unlikely to increase hospitalisations, outpatients' attendance or admissions for diabetes related complications.

Effects of Canagliflozin on Serum Magnesium in Patients With Type 2 Diabetes Mellitus: A Post Hoc Analysis of Randomized Controlled Trials

INTRODUCTION

The objective of this study was to evaluate the effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on serum magnesium in hypomagnesemic patients with type 2 diabetes.

METHODS

This post hoc analysis was based on pooled data from four placebo-controlled studies of canagliflozin (N = 2313). The proportion of patients with baseline serum magnesium <0.74 mmol/L who achieved serum magnesium ≥0.74 mmol/L at week 26 was evaluated.

RESULTS

At week 26, canagliflozin 100 and 300 mg increased serum magnesium versus placebo in patients with baseline serum magnesium <0.74 mmol/L (17.0% and 19.0% vs 3.9%) and ≥0.74 mmol/L (4.9% and 7.0% vs -1.4%). More patients with baseline serum magnesium <0.74 mmol/L had serum magnesium ≥0.74 mmol/L at week 26 with canagliflozin 100 and 300 mg versus placebo (74.1% and 80.6% vs 28.8%).

CONCLUSIONS

Canagliflozin was associated with normalization of serum magnesium in hypomagnesemic patients with type 2 diabetes, potentially leading to improved cardiometabolic outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifiers, NCT01081834, NCT01106677, NCT01106625, NCT01106690.

Efficacy and safety of canagliflozin in patients with type 2 diabetes based on history of cardiovascular disease or cardiovascular risk factors: a post hoc analysis of pooled data

Background

Treatment of patients with type 2 diabetes mellitus (T2DM) and a history of cardiovascular (CV) disease or CV risk factors may present clinical challenges due to the presence of comorbid conditions and the use of concomitant medications. The sodium glucose co-transporter 2 inhibitor, canagliflozin, has been shown to improve glycaemic control and reduce body weight and blood pressure (BP) with a favourable tolerability profile in a broad range of patients with T2DM. This post hoc analysis assessed the efficacy and safety of canagliflozin in patients with T2DM based on CV disease history or CV risk factors.

Methods

Analyses were based on pooled data from four 26-week, placebo-controlled, Phase 3 studies that evaluated canagliflozin 100 and 300 mg in patients with T2DM (N = 2313; mean HbA1c, 8.0%; body weight, 89 kg; systolic BP, 128 mmHg). Changes from baseline to week 26 in HbA1c, body weight, and systolic BP were assessed based on history of CV disease, history of hypertension, baseline statin use, and number of CV risk factors. Safety was assessed based on adverse event (AE) reports.

Results

At week 26, both canagliflozin doses lowered HbA1c, body weight, and systolic BP compared with placebo in patients with and without CV disease history or risk factors. Placebo-subtracted HbA1c reductions with canagliflozin 100 and 300 mg were similar in patients with a history of CV disease (−0.95 and −1.07%) versus no history of CV disease (−0.71 and −0.90%), history of hypertension (−0.72 and −0.89%) versus no history of hypertension (−0.73 and −0.95%), baseline statin use (−0.77 and −0.99%) versus no statin use (−0.69 and −0.85%), and 0–1 CV risk factor (−0.72 and −0.87%) versus ≥2 CV risk factors (−0.74 and −1.02%). Similar body weight and systolic BP reductions were seen with canagliflozin versus placebo across subgroups. The incidence of AEs, AEs leading to discontinuation, and serious AEs was similar across subgroups.

Conclusions

The efficacy and safety of canagliflozin were generally consistent across subgroups of patients with T2DM and varying degrees of CV disease history or risk factors.

Trial registration numbers and dates ClinicalTrials.gov: NCT01081834, 4 March 2010; NCT01106625, 1 April 2010; NCT01106677, 1 April 2010; NCT01106690, 1 April 2010

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0517-7) contains supplementary material, which is available to authorized users.

The effects of supervised exercise training 12-24 months after bariatric surgery on physical function and body composition: a randomised controlled trial

BACKGROUND

Bariatric surgery is effective for the treatment of stage II and III obesity and its related diseases, although increasing evidence is showing weight regain ~12-24 months postsurgery. Weight regain increases the risk of physical function decline, which negatively affects an individual's ability to undertake activities of daily living. The study assessed the effects of a 12-week supervised exercise intervention on physical function and body composition in patients between 12 and 24 months post bariatric surgery.

METHODS

Twenty-four inactive adult bariatric surgery patients whose body mass index remained ⩾30 kg m² 12 to 24 months post surgery were randomised to an exercise intervention (n=12) or control group (n=12). Supervised exercise consisted of three 60-min gym sessions per week of moderate intensity aerobic and resistance training for 12 weeks. Control participants received usual care. The incremental shuttle walk test (ISWT) was used to assess functional walking performance after the 12-week exercise intervention, and at 24 weeks follow-up. Measures of anthropometric, physical activity, cardiovascular and psychological outcomes were also examined. Using an intention-to-treat protocol, independent t-tests were used to compare outcome measures between groups.

RESULTS

Significant improvements in the exercise group were observed for the ISWT, body composition, physical function, cardiovascular and self-efficacy measures from baseline to 12 weeks. A large baseline to 12-week change was observed for the ISWT (exercise: 325.00±117.28 m; control: 355.00±80.62 m, P<0.001). The exercise group at 24 weeks recorded an overall mean improvement of 143.3±86.6 m and the control group recorded a reduction of -32.50±75.93 m. Findings show a 5.6 kg difference between groups in body mass change from baseline to 24 weeks favouring the exercise group.

CONCLUSIONS

A 12-week supervised exercise intervention led to significant improvements in body mass and functional walking ability post intervention, with further improvements at the 24-week follow-up.

Longer-term safety and tolerability of canagliflozin in patients with type 2 diabetes: a pooled analysis

OBJECTIVE

To evaluate the longer-term safety of canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes mellitus (T2DM).

METHODS

The safety/tolerability of canagliflozin 100 and 300 mg were assessed using data pooled from seven placebo- and active-controlled studies of 52-104 weeks in duration that enrolled a broad range of patients with T2DM (N = 5598). Canagliflozin 100 and 300 mg as monotherapy or in combination with various background antihyperglycemic agents (AHAs) were compared with pooled non-canagliflozin treatments (i.e. placebo, sitagliptin, glimepiride). Safety was assessed based on adverse event (AE) reports, including the incidence of AEs related to the mechanism of SGLT2 inhibition.

RESULTS

Overall AE incidence was similar with canagliflozin 100 and 300 mg and non-canagliflozin (73.7%, 74.5%, and 73.7%). The incidence of AE-related discontinuations and serious AEs was low and balanced across groups. The incidence of male and female genital mycotic infections, urinary tract infections, and AEs related to osmotic diuresis or volume depletion was higher with canagliflozin versus non-canagliflozin; these AEs generally occurred early with decreased incidence over time and incidence was similar across baseline HbA1c subgroups. The incidence of fractures and diabetic ketoacidosis was low and similar across groups. Canagliflozin was associated with a low incidence of hypoglycemia when used with background AHAs that are not associated with hypoglycemia; the incidence was higher among patients on background AHAs associated with hypoglycemia (i.e. insulin, sulfonylurea, glinide).

LIMITATIONS

Limitations of this analysis include its post hoc nature. While this analysis included a broad population of patients, including those with a history or risk of cardiovascular disease or chronic kidney disease, the longer-term safety in these patient populations was not specifically evaluated. Ongoing outcome studies will provide data on the long-term safety of canagliflozin in these populations.

CONCLUSIONS

Longer-term exposure to canagliflozin as monotherapy or in combination with other agents was generally well tolerated in patients with T2DM.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT01106625, NCT01081834, NCT01106677, NCT00968812, NCT01106651, NCT01106690, NCT01137812.

Incident Type 2 diabetes and the effect of early regression to normoglycaemia in a population with impaired glucose regulation

AIMS

To report contemporary regression rates from impaired glucose regulation to normal glucose tolerance, identify modifiable factors associated with early regression, and establish whether it affects subsequent diabetes risk in a population-based cohort.

METHODS

Participants with impaired glucose regulation (impaired fasting glucose and/or impaired glucose tolerance on a 75-g oral glucose tolerance test) at baseline in the UK-based ADDITION-Leicester study had annual Type 2 diabetes re-screens for 5 years or until diabetes diagnosis. Logistic regression models investigated modifiable risk factors for regression to normal glucose tolerance at 1 year (n = 817). Cox regression models estimated subsequent diabetes risk (n = 630).

RESULTS

At 1 year, 54% of participants had regressed to normal glucose tolerance, and 6% had progressed to diabetes. Regression to normal glucose tolerance was associated with weight loss of 0.1-3% [adjusted odds ratio 1.81 (95% CI 1.08, 3.03) compared with maintaining or gaining weight] and a waist circumference reduction of > 3 cm [adjusted odds ratio 1.78 (95% CI 1.03, 3.06) compared with maintaining or increasing waist circumference]. Those with normal glucose tolerance at 1 year subsequently had lower diabetes risk than those who remained with impaired glucose regulation [adjusted hazard ratio 0.19 (95% CI 0.10, 0.37)].

CONCLUSIONS

Early regression to normal glucose tolerance was associated with reduced diabetes incidence, and might be induced by small reductions in weight or waist circumference. If confirmed in experimental research, this could be a clear and achievable target for individuals diagnosed with impaired glucose regulation.

Effects of canagliflozin, a sodium glucose co-transporter 2 inhibitor, on blood pressure and markers of arterial stiffness in patients with type 2 diabetes mellitus: a post hoc analysis

Background

Physiologic determinants, such as pulse pressure [difference between systolic blood pressure (SBP) and diastolic BP (DBP)], mean arterial pressure (2/3 DBP + 1/3 SBP), and double product [beats per minute (bpm) × SBP], are linked to cardiovascular outcomes. The effects of canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, on pulse pressure, mean arterial pressure, and double product were assessed in patients with type 2 diabetes mellitus (T2DM).

Methods

This post hoc analysis was based on pooled data from four 26-week, randomized, double-blind, placebo-controlled studies evaluating canagliflozin in patients with T2DM (N = 2313) and a 6-week, randomized, double-blind, placebo-controlled, ambulatory BP monitoring (ABPM) study evaluating canagliflozin in patients with T2DM and hypertension (N = 169). Changes from baseline in SBP, DBP, pulse pressure, mean arterial pressure, and double product were assessed using seated BP measurements (pooled studies) or averaged 24-h BP assessments (ABPM study). Safety was assessed based on adverse event reports.

Results

In the pooled studies, canagliflozin 100 and 300 mg reduced SBP (−4.3 and −5.0 vs −0.3 mmHg) and DBP (−2.5 and −2.4 vs −0.6 mmHg) versus placebo at week 26. Reductions in pulse pressure (−1.8 and −2.6 vs 0.2 mmHg), mean arterial pressure (−3.1 and −3.3 vs −0.5 mmHg), and double product (−381 and −416 vs −30 bpm × mmHg) were also seen with canagliflozin 100 and 300 mg versus placebo. In the ABPM study, canagliflozin 100 and 300 mg reduced mean 24-h SBP (−4.5 and −6.2 vs −1.2 mmHg) and DBP (−2.2 and −3.2 vs −0.3 mmHg) versus placebo at week 6. Canagliflozin 300 mg provided reductions in pulse pressure (−3.3 vs −0.8 mmHg) and mean arterial pressure (−4.2 vs −0.6 mmHg) compared with placebo, while canagliflozin 100 mg had more modest effects on these parameters. Canagliflozin was generally well tolerated in both study populations.

Conclusions

Canagliflozin improved all three cardiovascular physiologic markers, consistent with the hypothesis that canagliflozin may have beneficial effects on some cardiovascular outcomes in patients with T2DM.

Trial registration ClinicalTrials.gov Identifier: NCT01081834 (registered March 2010); NCT01106677 (registered April 2010); NCT01106625 (registered April 2010); NCT01106690 (registered April 2010); NCT01939496 (registered September 2013)

Cost-effectiveness of a pragmatic structured education intervention for the prevention of type 2 diabetes: economic evaluation of data from the Let's Prevent Diabetes cluster-randomised controlled trial

OBJECTIVES

Prevention of type 2 diabetes mellitus (TD2M) is a priority for healthcare systems. We estimated the cost-effectiveness compared with standard care of a structured education programme (Let's Prevent) targeting lifestyle and behaviour change to prevent progression to T2DM in people with prediabetes.

DESIGN

Cost-effectiveness analysis alongside randomised controlled trial.

SETTING

44 general practices in Leicestershire, England.

PARTICIPANTS

880 participants with prediabetes randomised to receive either standard care or a 6-hour group structured education programme with follow-up sessions in a primary care setting.

MAIN OUTCOME MEASURE

Incremental cost utility from the UK National Health Service (NHS) perspective. Quality of life and resource use measured from baseline and during the 36 months follow-up using the EuroQoL EQ-5D and 15D instruments and an economic questionnaire. Outcomes measured using quality-adjusted life years (QALYs) and healthcare costs calculated in 2012-2013 prices.

RESULTS

After accounting for clustering and missing data, the intervention group was found to have a net gain of 0.046 (95% CI -0.0171 to 0.109) QALYs over 3 years, adjusted for baseline utility, at an additional cost of £168 (95% CI -395 to 732) per patient compared with the standard care group. The incremental cost-effectiveness ratio is £3643/QALY with an 86% probability of being cost-effective at a willingness to pay threshold of £20 000/QALY.

CONCLUSIONS

The education programme had higher costs and higher quality of life compared with the standard care group. The Let's Prevent programme is very likely to be cost-effective at a willingness to pay threshold of £20 000/QALY gained.

TRIAL REGISTRATION NUMBER

ISRCTN80605705.