Persistence of immune responses after heterologous and homologous third COVID-19 vaccine dose schedules in the UK: eight-month analyses of the COV-BOOST trial

BACKGROUND

COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose in June 2021. Monovalent messenger RNA (mRNA) COVID-19 vaccines were subsequently widely used for the third and fourth-dose vaccination campaigns in high-income countries. Real-world vaccine effectiveness against symptomatic infections following third doses declined during the Omicron wave. This report compares the immunogenicity and kinetics of responses to third doses of vaccines from day (D) 28 to D242 following third doses in seven study arms.

METHODS

The trial initially included ten experimental vaccine arms (seven full-dose, three half-dose) delivered at three groups of six sites. Participants in each site group were randomised to three or four experimental vaccines, or MenACWY control. The trial was stratified such that half of participants had previously received two primary doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd) and half had received two doses of BNT162b2 (Pfizer-BioNtech, hereafter referred to as BNT). The D242 follow-up was done in seven arms (five full-dose, two half-dose). The BNT vaccine was used as the reference as it was the most commonly deployed third-dose vaccine in clinical practice in high-income countries. The primary analysis was conducted using all randomised and baseline seronegative participants who were SARS-CoV-2 naïve during the study and who had not received a further COVID-19 vaccine for any reason since third dose randomisation.

RESULTS

Among the 817 participants included in this report, the median age was 72 years (IQR: 55-78) with 50.7% being female. The decay rates of anti-spike IgG between vaccines are different among both populations who received initial doses of ChAd/ChAd and BNT/BNT. In the population that previously received ChAd/ChAd, mRNA vaccines had the highest titre at D242 following their vaccine dose although Ad26. COV2. S (Janssen; hereafter referred to as Ad26) showed slower decay. For people who received BNT/BNT as their initial doses, a slower decay was also seen in the Ad26 and ChAd arms. The anti-spike IgG became significantly higher in the Ad26 arm compared to the BNT arm as early as 3 months following vaccination. Similar decay rates were seen between BNT and half-BNT; the geometric mean ratios ranged from 0.76 to 0.94 at different time points. The difference in decay rates between vaccines was similar for wild-type live virus-neutralising antibodies and that seen for anti-spike IgG. For cellular responses, the persistence was similar between study arms.

CONCLUSIONS

Heterologous third doses with viral vector vaccines following two doses of mRNA achieve more durable humoral responses compared with three doses of mRNA vaccines. Lower doses of mRNA vaccines could be considered for future booster campaigns.

Safety, immunogenicity, and reactogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines given as fourth-dose boosters following two doses of ChAdOx1 nCoV-19 or BNT162b2 and a third dose of BNT162b2 (COV-BOOST): a multicentre, blinded, phase 2, randomised trial

BACKGROUND

Some high-income countries have deployed fourth doses of COVID-19 vaccines, but the clinical need, effectiveness, timing, and dose of a fourth dose remain uncertain. We aimed to investigate the safety, reactogenicity, and immunogenicity of fourth-dose boosters against COVID-19.

METHODS

The COV-BOOST trial is a multicentre, blinded, phase 2, randomised controlled trial of seven COVID-19 vaccines given as third-dose boosters at 18 sites in the UK. This sub-study enrolled participants who had received BNT162b2 (Pfizer-BioNTech) as their third dose in COV-BOOST and randomly assigned them (1:1) to receive a fourth dose of either BNT162b2 (30 μg in 0·30 mL; full dose) or mRNA-1273 (Moderna; 50 μg in 0·25 mL; half dose) via intramuscular injection into the upper arm. The computer-generated randomisation list was created by the study statisticians with random block sizes of two or four. Participants and all study staff not delivering the vaccines were masked to treatment allocation. The coprimary outcomes were safety and reactogenicity, and immunogenicity (anti-spike protein IgG titres by ELISA and cellular immune response by ELISpot). We compared immunogenicity at 28 days after the third dose versus 14 days after the fourth dose and at day 0 versus day 14 relative to the fourth dose. Safety and reactogenicity were assessed in the per-protocol population, which comprised all participants who received a fourth-dose booster regardless of their SARS-CoV-2 serostatus. Immunogenicity was primarily analysed in a modified intention-to-treat population comprising seronegative participants who had received a fourth-dose booster and had available endpoint data. This trial is registered with ISRCTN, 73765130, and is ongoing.

FINDINGS

Between Jan 11 and Jan 25, 2022, 166 participants were screened, randomly assigned, and received either full-dose BNT162b2 (n=83) or half-dose mRNA-1273 (n=83) as a fourth dose. The median age of these participants was 70·1 years (IQR 51·6-77·5) and 86 (52%) of 166 participants were female and 80 (48%) were male. The median interval between the third and fourth doses was 208·5 days (IQR 203·3-214·8). Pain was the most common local solicited adverse event and fatigue was the most common systemic solicited adverse event after BNT162b2 or mRNA-1273 booster doses. None of three serious adverse events reported after a fourth dose with BNT162b2 were related to the study vaccine. In the BNT162b2 group, geometric mean anti-spike protein IgG concentration at day 28 after the third dose was 23 325 ELISA laboratory units (ELU)/mL (95% CI 20 030-27 162), which increased to 37 460 ELU/mL (31 996-43 857) at day 14 after the fourth dose, representing a significant fold change (geometric mean 1·59, 95% CI 1·41-1·78). There was a significant increase in geometric mean anti-spike protein IgG concentration from 28 days after the third dose (25 317 ELU/mL, 95% CI 20 996-30 528) to 14 days after a fourth dose of mRNA-1273 (54 936 ELU/mL, 46 826-64 452), with a geometric mean fold change of 2·19 (1·90-2·52). The fold changes in anti-spike protein IgG titres from before (day 0) to after (day 14) the fourth dose were 12·19 (95% CI 10·37-14·32) and 15·90 (12·92-19·58) in the BNT162b2 and mRNA-1273 groups, respectively. T-cell responses were also boosted after the fourth dose (eg, the fold changes for the wild-type variant from before to after the fourth dose were 7·32 [95% CI 3·24-16·54] in the BNT162b2 group and 6·22 [3·90-9·92] in the mRNA-1273 group).

INTERPRETATION

Fourth-dose COVID-19 mRNA booster vaccines are well tolerated and boost cellular and humoral immunity. Peak responses after the fourth dose were similar to, and possibly better than, peak responses after the third dose.

FUNDING

UK Vaccine Task Force and National Institute for Health Research.

Persistence of immunogenicity after seven COVID-19 vaccines given as third dose boosters following two doses of ChAdOx1 nCov-19 or BNT162b2 in the UK: Three month analyses of the COV-BOOST trial

OBJECTIVES

To evaluate the persistence of immunogenicity three months after third dose boosters.

METHODS

COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose. The analysis was conducted using all randomised participants who were SARS-CoV-2 naïve during the study.

RESULTS

Amongst the 2883 participants randomised, there were 2422 SARS-CoV-2 naïve participants until D84 visit included in the analysis with median age of 70 (IQR: 30-94) years. In the participants who had two initial doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd), schedules using mRNA vaccines as third dose have the highest anti-spike IgG at D84 (e.g. geometric mean concentration of 8674 ELU/ml (95% CI: 7461-10,085) following ChAd/ChAd/BNT162b2 (Pfizer-BioNtech, hearafter referred to as BNT)). However, in people who had two initial doses of BNT there was no significant difference at D84 in people given ChAd versus BNT (geometric mean ratio (GMR) of 0.95 (95%CI: 0.78, 1.15). Also, people given Ad26.COV2.S (Janssen; hereafter referred to as Ad26) as a third dose had significantly higher anti-spike IgG at D84 than BNT (GMR of 1.20, 95%CI: 1.01,1.43). Responses at D84 between people who received BNT (15 μg) or BNT (30 μg) after ChAd/ChAd or BNT/BNT were similar, with anti-spike IgG GMRs of half-BNT (15 μg) versus BNT (30 μg) ranging between 0.74-0.86. The decay rate of cellular responses were similar between all the vaccine schedules and doses.

CONCLUSIONS

84 days after a third dose of COVID-19 vaccine the decay rates of humoral response were different between vaccines. Adenoviral vector vaccine anti-spike IgG concentrations at D84 following BNT/BNT initial doses were similar to or even higher than for a three dose (BNT/BNT/BNT) schedule. Half dose BNT immune responses were similar to full dose responses. While high antibody tires are desirable in situations of high transmission of new variants of concern, the maintenance of immune responses that confer long-lasting protection against severe disease or death is also of critical importance. Policymakers may also consider adenoviral vector, fractional dose of mRNA, or other non-mRNA vaccines as third doses.

Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial

BACKGROUND

Older adults (aged ≥70 years) are at increased risk of severe disease and death if they develop COVID-19 and are therefore a priority for immunisation should an efficacious vaccine be developed. Immunogenicity of vaccines is often worse in older adults as a result of immunosenescence. We have reported the immunogenicity of a novel chimpanzee adenovirus-vectored vaccine, ChAdOx1 nCoV-19 (AZD1222), in young adults, and now describe the safety and immunogenicity of this vaccine in a wider range of participants, including adults aged 70 years and older.

METHODS

In this report of the phase 2 component of a single-blind, randomised, controlled, phase 2/3 trial (COV002), healthy adults aged 18 years and older were enrolled at two UK clinical research facilities, in an age-escalation manner, into 18-55 years, 56-69 years, and 70 years and older immunogenicity subgroups. Participants were eligible if they did not have severe or uncontrolled medical comorbidities or a high frailty score (if aged ≥65 years). First, participants were recruited to a low-dose cohort, and within each age group, participants were randomly assigned to receive either intramuscular ChAdOx1 nCoV-19 (2·2 × 1010 virus particles) or a control vaccine, MenACWY, using block randomisation and stratified by age and dose group and study site, using the following ratios: in the 18-55 years group, 1:1 to either two doses of ChAdOx1 nCoV-19 or two doses of MenACWY; in the 56-69 years group, 3:1:3:1 to one dose of ChAdOx1 nCoV-19, one dose of MenACWY, two doses of ChAdOx1 nCoV-19, or two doses of MenACWY; and in the 70 years and older, 5:1:5:1 to one dose of ChAdOx1 nCoV-19, one dose of MenACWY, two doses of ChAdOx1 nCoV-19, or two doses of MenACWY. Prime-booster regimens were given 28 days apart. Participants were then recruited to the standard-dose cohort (3·5-6·5 × 1010 virus particles of ChAdOx1 nCoV-19) and the same randomisation procedures were followed, except the 18-55 years group was assigned in a 5:1 ratio to two doses of ChAdOx1 nCoV-19 or two doses of MenACWY. Participants and investigators, but not staff administering the vaccine, were masked to vaccine allocation. The specific objectives of this report were to assess the safety and humoral and cellular immunogenicity of a single-dose and two-dose schedule in adults older than 55 years. Humoral responses at baseline and after each vaccination until 1 year after the booster were assessed using an in-house standardised ELISA, a multiplex immunoassay, and a live severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) microneutralisation assay (MNA80). Cellular responses were assessed using an ex-vivo IFN-γ enzyme-linked immunospot assay. The coprimary outcomes of the trial were efficacy, as measured by the number of cases of symptomatic, virologically confirmed COVID-19, and safety, as measured by the occurrence of serious adverse events. Analyses were by group allocation in participants who received the vaccine. Here, we report the preliminary findings on safety, reactogenicity, and cellular and humoral immune responses. This study is ongoing and is registered with ClinicalTrials.gov, NCT04400838, and ISRCTN, 15281137.

FINDINGS

Between May 30 and Aug 8, 2020, 560 participants were enrolled: 160 aged 18-55 years (100 assigned to ChAdOx1 nCoV-19, 60 assigned to MenACWY), 160 aged 56-69 years (120 assigned to ChAdOx1 nCoV-19: 40 assigned to MenACWY), and 240 aged 70 years and older (200 assigned to ChAdOx1 nCoV-19: 40 assigned to MenACWY). Seven participants did not receive the boost dose of their assigned two-dose regimen, one participant received the incorrect vaccine, and three were excluded from immunogenicity analyses due to incorrectly labelled samples. 280 (50%) of 552 analysable participants were female. Local and systemic reactions were more common in participants given ChAdOx1 nCoV-19 than in those given the control vaccine, and similar in nature to those previously reported (injection-site pain, feeling feverish, muscle ache, headache), but were less common in older adults (aged ≥56 years) than younger adults. In those receiving two standard doses of ChAdOx1 nCoV-19, after the prime vaccination local reactions were reported in 43 (88%) of 49 participants in the 18-55 years group, 22 (73%) of 30 in the 56-69 years group, and 30 (61%) of 49 in the 70 years and older group, and systemic reactions in 42 (86%) participants in the 18-55 years group, 23 (77%) in the 56-69 years group, and 32 (65%) in the 70 years and older group. As of Oct 26, 2020, 13 serious adverse events occurred during the study period, none of which were considered to be related to either study vaccine. In participants who received two doses of vaccine, median anti-spike SARS-CoV-2 IgG responses 28 days after the boost dose were similar across the three age cohorts (standard-dose groups: 18-55 years, 20 713 arbitrary units [AU]/mL [IQR 13 898-33 550], n=39; 56-69 years, 16 170 AU/mL [10 233-40 353], n=26; and ≥70 years 17 561 AU/mL [9705-37 796], n=47; p=0·68). Neutralising antibody titres after a boost dose were similar across all age groups (median MNA80 at day 42 in the standard-dose groups: 18-55 years, 193 [IQR 113-238], n=39; 56-69 years, 144 [119-347], n=20; and ≥70 years, 161 [73-323], n=47; p=0·40). By 14 days after the boost dose, 208 (>99%) of 209 boosted participants had neutralising antibody responses. T-cell responses peaked at day 14 after a single standard dose of ChAdOx1 nCoV-19 (18-55 years: median 1187 spot-forming cells [SFCs] per million peripheral blood mononuclear cells [IQR 841-2428], n=24; 56-69 years: 797 SFCs [383-1817], n=29; and ≥70 years: 977 SFCs [458-1914], n=48).

INTERPRETATION

ChAdOx1 nCoV-19 appears to be better tolerated in older adults than in younger adults and has similar immunogenicity across all age groups after a boost dose. Further assessment of the efficacy of this vaccine is warranted in all age groups and individuals with comorbidities.

FUNDING

UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midlands NIHR Clinical Research Network, and AstraZeneca.

Safety and immunogenicity of seven COVID-19 vaccines as a third dose (booster) following two doses of ChAdOx1 nCov-19 or BNT162b2 in the UK (COV-BOOST): a blinded, multicentre, randomised, controlled, phase 2 trial

BACKGROUND

Few data exist on the comparative safety and immunogenicity of different COVID-19 vaccines given as a third (booster) dose. To generate data to optimise selection of booster vaccines, we investigated the reactogenicity and immunogenicity of seven different COVID-19 vaccines as a third dose after two doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd) or BNT162b2 (Pfizer-BioNtech, hearafter referred to as BNT).

METHODS

COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of third dose booster vaccination against COVID-19. Participants were aged older than 30 years, and were at least 70 days post two doses of ChAd or at least 84 days post two doses of BNT primary COVID-19 immunisation course, with no history of laboratory-confirmed SARS-CoV-2 infection. 18 sites were split into three groups (A, B, and C). Within each site group (A, B, or C), participants were randomly assigned to an experimental vaccine or control. Group A received NVX-CoV2373 (Novavax; hereafter referred to as NVX), a half dose of NVX, ChAd, or quadrivalent meningococcal conjugate vaccine (MenACWY)control (1:1:1:1). Group B received BNT, VLA2001 (Valneva; hereafter referred to as VLA), a half dose of VLA, Ad26.COV2.S (Janssen; hereafter referred to as Ad26) or MenACWY (1:1:1:1:1). Group C received mRNA1273 (Moderna; hereafter referred to as m1273), CVnCov (CureVac; hereafter referred to as CVn), a half dose of BNT, or MenACWY (1:1:1:1). Participants and all investigatory staff were blinded to treatment allocation. Coprimary outcomes were safety and reactogenicity and immunogenicity of anti-spike IgG measured by ELISA. The primary analysis for immunogenicity was on a modified intention-to-treat basis; safety and reactogenicity were assessed in the intention-to-treat population. Secondary outcomes included assessment of viral neutralisation and cellular responses. This trial is registered with ISRCTN, number 73765130.

FINDINGS

Between June 1 and June 30, 2021, 3498 people were screened. 2878 participants met eligibility criteria and received COVID-19 vaccine or control. The median ages of ChAd/ChAd-primed participants were 53 years (IQR 44-61) in the younger age group and 76 years (73-78) in the older age group. In the BNT/BNT-primed participants, the median ages were 51 years (41-59) in the younger age group and 78 years (75-82) in the older age group. In the ChAd/ChAD-primed group, 676 (46·7%) participants were female and 1380 (95·4%) were White, and in the BNT/BNT-primed group 770 (53·6%) participants were female and 1321 (91·9%) were White. Three vaccines showed overall increased reactogenicity: m1273 after ChAd/ChAd or BNT/BNT; and ChAd and Ad26 after BNT/BNT. For ChAd/ChAd-primed individuals, spike IgG geometric mean ratios (GMRs) between study vaccines and controls ranged from 1·8 (99% CI 1·5-2·3) in the half VLA group to 32·3 (24·8-42·0) in the m1273 group. GMRs for wild-type cellular responses compared with controls ranged from 1·1 (95% CI 0·7-1·6) for ChAd to 3·6 (2·4-5·5) for m1273. For BNT/BNT-primed individuals, spike IgG GMRs ranged from 1·3 (99% CI 1·0-1·5) in the half VLA group to 11·5 (9·4-14·1) in the m1273 group. GMRs for wild-type cellular responses compared with controls ranged from 1·0 (95% CI 0·7-1·6) for half VLA to 4·7 (3·1-7·1) for m1273. The results were similar between those aged 30-69 years and those aged 70 years and older. Fatigue and pain were the most common solicited local and systemic adverse events, experienced more in people aged 30-69 years than those aged 70 years or older. Serious adverse events were uncommon, similar in active vaccine and control groups. In total, there were 24 serious adverse events: five in the control group (two in control group A, three in control group B, and zero in control group C), two in Ad26, five in VLA, one in VLA-half, one in BNT, two in BNT-half, two in ChAd, one in CVn, two in NVX, two in NVX-half, and one in m1273.

INTERPRETATION

All study vaccines boosted antibody and neutralising responses after ChAd/ChAd initial course and all except one after BNT/BNT, with no safety concerns. Substantial differences in humoral and cellular responses, and vaccine availability will influence policy choices for booster vaccination.

FUNDING

UK Vaccine Taskforce and National Institute for Health Research.

The Effect of Haematocrit on Measurement of the Mid-Infrared Refractive Index of Plasma in Whole Blood

Recent advances suggest that miniaturised mid-infrared (MIR) devices could replace more time-consuming, laboratory-based techniques for clinical diagnostics. This work uses Fourier transform infrared spectroscopy to show that the MIR complex refractive index of whole blood varies across a range of haematocrit. This indicates that the use of an evanescent measurement is not sufficient to optically exclude the cellular content of blood in the MIR, as previously assumed. Here, spectral refractive index data is presented in two ways. First, it is given as whole blood with varying haematocrit. Second, it is given as the percentage error that haematocrit introduces to plasma. The maximum error in the effective plasma refractive index due to the haematocrit of healthy adults was 0.25% for the real part n and 11% for the imaginary part k. This implies that calibration measurements of haematocrit can be used to account for errors introduced by the cellular content, enabling plasma spectra and analyte concentrations to be indirectly calculated from a whole blood sample. This methodological advance is of clinical importance as plasma concentration of analytes such as drugs can be determined using MIR without the preprocessing of whole blood.

Problem-solving in clinical practice: Persisting respiratory distress in a premature infant

The deterioration of a previously stable preterm infant is a common scenario on the neonatal unit. The the most common bacterial causes of deterioration are nosocomial infections, such as coagulase-negative Staphylococcus and Staphylococcus aureus Non-infective conditions such as pulmonary haemorrhage, anaemia of prematurity and necrotising enterocolitis may also cause preterm infants to deteriorate. This case chronicles the unusual diagnostic journey of an infant born at 27+1 weeks who deteriorated at 26 days of life and did not respond to antimicrobial therapy as anticipated.

COVID-19 symptom surveillance in immunocompromised children and young people in the UK: a prospective observational cohort study

OBJECTIVES

To describe the frequency of symptoms compatible with SARS-CoV-2 infection in immunocompromised children and young people in the UK during the SARS-CoV-2 pandemic. To describe patient/parent anxiety regarding SARS-CoV-2 infection in this cohort.

DESIGN

A prospective observational cohort study.

SETTING

46 centres across the UK between 16 March and 4 July 2020. A weekly online questionnaire based on the International Severe Acute Respiratory and emerging Infections Consortium-WHO Case Report Form was used to collect participant reported data on symptoms, test results, National Health Service attendance, hospital admission and impact on daily life.

PARTICIPANTS

1490 immunocompromised children, defined as those requiring an annual influenza vaccination due to their underlying condition or medication.

MAIN OUTCOME MEASURES

Incidence of SARS-CoV-2-like symptoms and patient/parent anxiety score.

RESULTS

Over 16 weeks during the first wave of the pandemic, no SARS-CoV-2 infection was diagnosed in this large immunocompromised paediatric cohort (median age 11 years, 54.4% female). 110 symptomatic participants underwent a test for SARS-CoV-2; all were negative. 922 (67.4%) participants reported at least one symptom consistent with suspected SARS-CoV-2 infection over the study period. 476 (34.8%) reported three or more symptoms. The most frequently reported symptoms included joint pain, fatigue, headache, nausea and muscle pain. SARS-CoV-2 testing during this period was performed on admitted patients only. 137 participants had their medication suspended or changed during the study period due to assumed COVID-19 disease risk. 62% reported high levels of anxiety (scores of 7-10 out of 10) at the start of the study, with anxiety levels remaining high throughout the study period.

CONCLUSIONS

Although symptoms related to SARS-CoV-2 infection in children were common, there were no positive tests in this large immunocompromised cohort. Symptom-based screening to facilitate early detection of SARS-CoV-2 infection may not be helpful in these individuals. Patient/parent anxiety about SARS-CoV-2 infection was high.

TRIAL REGISTRATION NUMBER

NCT04382508.

High frequency of paediatric facial nerve palsy due to Lyme disease in a geographically endemic region

INTRODUCTION

Idiopathic facial nerve palsy (FNP) is an uncommon but important presentation in children, with Lyme disease known to be a common cause. The UK county of Hampshire is a high incidence area of Lyme disease. We conducted a retrospective review of the investigation and management of paediatric FNP at a large University hospital, including serologic testing and treatment of Lyme disease.

METHODS

We conducted a retrospective chart review of children under 18 presenting between January 1st^, 2010 and December 31st^, 2017 with a diagnosis of FNP. Patients with clear non-Lyme aetiology at presentation were excluded. Data was collected on demographics, initial presentation, investigations including Lyme serology, and management.

RESULTS

A total of 93 children were identified, with an even proportion of male to female and median age 9.3 years (IQR 4.6-12 years). A history of rash was present in 5.4%, tick bite in 14% and recent travel to, or residence in the New Forest in 22.6%. Lyme serology was performed in 81.7% of patients, of which 29% were positive. Antibiotics were prescribed for 73.1% of patients, oral steroids for 44% and aciclovir for 17.2%.

CONCLUSION

Lyme disease is a significant cause of FNP in this endemic area of the UK, and there was a large degree of variability in management prior to national guideline publication. Areas with endemic Lyme disease should consider introducing local guidelines supporting routine investigation and management for FNP, including empiric treatment for Lyme disease in accordance with NICE guidelines to improve care and reduce variability.

IDF Diabetes Atlas: A review of studies utilising retinal photography on the global prevalence of diabetes related retinopathy between 2015 and 2018

AIMS

The purpose of this study is to assess the prevalence of diabetic retinopathy (DR) world-wide from articles published since 2015 where the assessment of the presence and severity of DR was based on retinal images.

METHODS

A total of 4 databases were searched for the MESH terms diabetic retinopathy and prevalence. Of 112 publications 32 studies were included and individual data pooled for analysis. The presence of any DR or diabetic macular edema (DME) was recorded and severity as mild, moderate or severe non-proliferative DR (NPDR), proliferative DR (PDR) and DME and/or clinically significant macular edema (CSME). The level of severity of DR reported refer to persons with diabetes and not individual eyes.

RESULTS

The global prevalence of DR and DME, for the period 2015 to 2019 were 27.0% for any DR comprising of 25.2%, NPDR, 1.4% PDR and 4.6% DME. The lowest prevalence was in Europe at 20.6% and South East Asia at 12.5% and highest in Africa at 33.8%, Middle East and North Africa 33.8%, and the Western Pacific region at 36.2%.

CONCLUSIONS

This study illustrated difficulties in deriving a meaningful global prevalence rate for DR and DME due to the lack of uniformity in defining the study populations, methodological differences, retinal image capture and grading criteria. Therefore, international consensus is required using a minimal data set for future studies.

The application of simple metrics in the assessment of glycaemic variability

The assessment of glycaemic variability (GV) remains a subject of debate with many indices proposed to represent either short- (acute glucose fluctuations) or long-term GV (variations of HbA_1c). For the assessment of short-term within-day GV, the coefficient of variation for glucose (%CV) defined as the standard deviation adjusted on the 24-h mean glucose concentration is easy to perform and with a threshold of 36%, recently adopted by the international consensus on use of continuous glucose monitoring, separating stable from labile glycaemic states. More complex metrics such as the Low Blood Glucose Index (LBGI) or High Blood Glucose Index (HBGI) allow the risk of hypo or hyperglycaemic episodes, respectively to be assessed although in clinical practice its application is limited due to the need for more complex computation. This also applies to other indices of short-term intraday GV including the mean amplitude of glycemic excursions (MAGE), Shlichtkrull's M-value and CONGA. GV is important clinically as exaggerated glucose fluctuations are associated with an enhanced risk of adverse cardiovascular outcomes due primarily to hypoglycaemia. In contrast, there is at present no compelling evidence that elevated short-term GV is an independent risk factor of microvascular complications of diabetes. Concerning long-term GV there are numerous studies supporting its association with an enhanced risk of cardiovascular events. However, this association raises the question as to whether the impact of long-term variability is not simply the consequence of repeated exposure to short-term GV or ambient chronic hyperglycaemia. The renewed emphasis on glucose monitoring with the introduction of continuous glucose monitoring technologies can benefit from the introduction and application of simple metrics for describing GV along with supporting recommendations.

Near normal HbA1c with stable glucose homeostasis: the ultimate target/aim of diabetes therapy

Achieving near normal glucose homeostasis implies that all components of dysglycemia that are present in diabetes states be eliminated. Reducing ambient/overall hyperglycemia is a pre-requisite to eliminate the risk of development and progression of diabetes complications. More controversially however, are the relative and related contributions of postprandial glucose excursions, glucose variability, hypoglycemia and the dawn phenomenon across the spectrum of dysglycemia. For instance, it is likely that the dawn phenomenon contributes to ambient hyperglycemia and that postprandial glucose excursions are at the cross road of ambient hyperglycemia and glucose variability with glucose fluctuations as causative risk factors for hypoglycemia. Proof-of-concept trials such as the ongoing FLAT-SUGAR study are necessary for gaining further insight into the possible harmful effects of some of these features such as excessive glycemic variability and glucose excursions, still considered to be of minor relevance by several diabetologists. Whether their role will be more thoroughly proven through further intervention trials with "hard" endpoints, remains to be seen. In the meantime more consideration should be given to medications aimed at concomitantly reducing ambient/overall hyperglycemia and those additional abnormal glycemic features of dysglycemia.

Lixisenatide, a novel GLP-1 receptor agonist: efficacy, safety and clinical implications for type 2 diabetes mellitus

Recent advances in therapies for the treatment of type 2 diabetes mellitus (T2DM) have led to the development of glucagon-like peptide-1 receptor agonists (GLP-1 RAs), which, unlike insulin and sulphonylurea, are effective, with a low risk of hypoglycaemia. Lixisenatide is recommended as a once-daily GLP-1 RA for the treatment of T2DM. In persons with T2DM, lixisenatide 20 µg once-daily given by bolus subcutaneous injection improves insulin secretion and suppresses glucagon secretion in a glucose-dependent manner. Compared with the longer-acting GLP-1 RA liraglutide, lixisenatide achieved a significantly greater reduction in postprandial plasma glucose (PPG) during a standardized test breakfast in persons with T2DM otherwise insufficiently controlled on metformin alone. This is primarily due to the greater inhibition of gastric motility by lixisenatide compared with liraglutide. The efficacy and safety of lixisenatide was evaluated across a spectrum of T2DM in a series of phase III, randomized, placebo-controlled trials known as the GetGoal programme. Lixisenatide monotherapy or as add-on to oral antidiabetic agents or basal insulin achieved significant reductions in glycated haemoglobin, PPG and fasting plasma glucose, with either weight loss or no weight gain. The most frequent adverse events were gastrointestinal and transient in nature. Lixisenatide provides an easy, once-daily, single-dose, add-on treatment to oral antidiabetic agents or basal insulin for the management of T2DM, with little or no increased risk of hypoglycaemia and a potential beneficial effect on body weight.

Linagliptin treatment in subjects with type 2 diabetes with and without mild-to-moderate renal impairment

AIMS

Renal disease is a frequent comorbidity of type 2 diabetes mellitus (T2DM) and an important factor complicating the choice of glucose-lowering drugs. The aim of this analysis was to evaluate the efficacy and safety of the dipeptidyl peptidase (DPP)-4 inhibitor linagliptin (5 mg/day) in mono, dual or triple oral glucose-lowering regimens in subjects with T2DM and mild or moderate renal impairment (RI).

METHODS

In this pooled analysis of three 24-week, placebo-controlled, phase 3 trials, subjects with mild (estimated glomerular filtration rate (eGFR) 60-<90 ml/min/1.73 m(2) , n = 838) or moderate RI (30-<60 ml/min/1.73 m(2), n = 93) were compared with subjects with normal renal function (≥90 ml/min/1.73 m(2), n = 1212).

RESULTS

Subjects with RI were older, had longer duration of diabetes, and increased prevalence of diabetes-related comorbidities. After 24 weeks, linagliptin achieved consistent placebo-corrected mean glycated haemoglobin (HbA1c) changes across the three renal function categories: normal (-0.63%; p < 0.0001), mild RI (-0.67%; p < 0.0001) and moderate RI (-0.53%; p < 0.01), with no inter-group difference (p = 0.74). Renal function with linagliptin remained stable across all categories. In linagliptin-treated subjects, overall adverse event (AE) rates and serious AE rates were similar to placebo. The incidence of hypoglycaemia with linagliptin and placebo was 11.1 versus 6.9%, 11.9 versus 9.0% and 15.9 versus 12.0% in the normal, mild RI and moderate RI categories, respectively.

CONCLUSIONS

This pooled analysis provides evidence that linagliptin is an effective, well-tolerated and convenient treatment in subjects with T2DM and mild or moderate RI.

Differential effects of GLP-1 receptor agonists on components of dysglycaemia in individuals with type 2 diabetes mellitus

Metabolic consequences of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are the result of enhanced glucose-stimulated insulin secretion, inhibition of glucagon release, delayed gastric emptying and increased satiety. These attributes make GLP-1 agonists a treatment option in type 2 diabetes mellitus (T2DM). To optimise treatment choice, a detailed understanding of the effects of GLP-1 RAs on glucose homeostasis in individuals with T2DM is necessary. Although the various GLP-1 RAs share the same basic mechanisms of action, differences in pharmacokinetic/pharmacodynamic characteristics translate into differential effects on parameters of glycaemia. Head-to-head comparisons between long-acting non-prandial (liraglutide once daily and exenatide once weekly) and shorter-acting prandial (exenatide twice daily and lixisenatide once daily prandial) GLP-1 RAs confirm their differential effects on fasting plasma glucose (FPG) and post-prandial glucose (PPG). Liraglutide once daily and exenatide once weekly demonstrate greater reductions in FPG but lesser impacts on PPG excursions plasma than exenatide twice daily. Prandial GLP-1 RAs have a profound effect on post-prandial glycaemia, mediated by delaying gastric emptying, which is not subject to the tachyphylaxis occurring due to the sustained elevated plasma GLP-1 concentrations after treatment with long-acting GLP-1 RAs. Lixisenatide once-daily prandial, in contrast to liraglutide, strongly suppresses post-prandial glucagon secretion, further contributing to the more pronounced PPG-lowering effect found with lixisenatide. Evidence suggests that the GLP-1 RAs that predominantly target the prandial glucose excursions, such as exenatide twice daily and lixisenatide once-daily prandial, are therefore best used as combination therapy with basal insulin and will form an important new treatment option for individuals with T2DM.

Estimates of the relative and absolute diurnal contributions of fasting and post-prandial plasma glucose over a range of hyperglycaemia in type 2 diabetes

AIMS

To re-examine the relative and absolute contributions of fasting/pre-prandial glucose (FPG) and post-prandial glucose (PPG) to 24-h hyperglycaemia and HbA1c respectively in non-insulin treated subjects with type 2 diabetes (T2DM).

MATERIALS AND METHODS

A total of 52 T2DM subjects (37 men) had daytime 12h plasma glucose (PG) profiles determined in response to three serial identical test meals commencing at 08 00h with pre-prandial and frequent post-prandial blood samples collected. The overnight PG profile was derived by projecting the 20 00h glucose concentration to the pre-breakfast value at 08 00h. PPG exposure was calculated above fasting/pre-prandial value for each meal. Excess hyperglycaemia was calculated based on a PG>5.5mmol/L with fasting hyperglycaemia being the difference between the two measurements. The subjects were divided into five groups according to the HbA1c (Group 1<7.0%; Group 2: 7.0-<7.5; Group 3: 7.5-<8.0%; Group 4: 8.0-<9.0%; Group 5:≥9.0%). The 24h relative contribution of PPG exposure and fasting hyperglycaemia to excess hyperglycaemia and the absolute contribution of PPG and fasting hyperglycaemia to excess HbA1c (HbA1c - 5.1%) was calculated.

RESULTS

With deteriorating glycaemia, the relative contribution of PPG exposure decreased across the groups from 43.5% (HbA1c<7.0%) to 17.8% (HbA1c≥9.0%), whilst the contributions of fasting hyperglycaemia increased from 56.5% to 82.2% (P=0.004), respectively. The absolute contributions of PPG to excess HbA1c was 0.7%, which remained relatively stable across the spectrum of HbA1c, whilst fasting hyperglycaemia increased significantly from groups 1 to 5 (P<0.001).

CONCLUSIONS

Fasting hyperglycaemia contributes substantially in all groups, increasing as HbA1c deteriorates. The absolute contribution of PPG to excess HbA1c did not vary across the range of HbA1c, representing a significant relative contribution even in well-controlled subjects with a HbA1c<7.0%.

Does feeding by Halyomorpha halys (Hemiptera: Pentatomidae) reduce soybean seed quality and yield?

The nonnative brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), has become an abundant pest of mid-Atlantic soybean since its introduction in the mid-1990s. Currently, there is little information indicating how this new pest should be managed in soybean or if economic thresholds developed for native stink bugs should be adjusted. In 2010 and 2011, field cage studies were conducted in Beltsville, MD, and Suffolk, VA, to evaluate H. halys injury to three different soybean reproductive development stages. Cages were infested for 2 wk using densities of zero, one, two, four, or eight stink bugs (fifth instars and adults) per 0.3 row-m. Cage plots were harvested, and subsamples were taken to determine pod losses and seed quality. Feeding injury to soybean caused by H. halys was similar to that of native stink bugs, as evidenced by seed destruction, punctures, and destroyed pods. Densities of four stink bugs per 0.3 row-m resulted in significant seed damage in three of four experiments. The full flowering (R2) soybean development stage was least affected by H. halys feeding. The full pod (R4) and the full seed (R6) stage were similarly sensitive to injury. There was no significant yield loss was associated with stink bug densities at either location, although there were significant differences among stages in two of four experiments. The data do not indicate that threshold densities for H. halys should be different than for the native stink bugs.

Stepwise intensification of insulin therapy in type 2 diabetes management--exploring the concept of the basal-plus approach in clinical practice

Basal insulin provides an effective method for initiating insulin therapy in people with Type 2 diabetes, resulting in significant improvements in glycaemic control, lower rates of hypoglycaemia and less weight gain than either prandial or premixed insulin regimens. However, the progressive nature of Type 2 diabetes and the inability of basal insulin to correct excessive postprandial glucose excursions mean that insulin therapy will eventually need to be intensified, typically by adding prandial insulin as part of a basal-bolus or premixed insulin regimen. The aim of this review is to summarize recent clinical evidence for a staged 'basal-plus' strategy for insulin intensification where one, two or three prandial insulin injections are added to basal insulin according to individual need. In the early stages of insulin therapy, most individuals seem to achieve favourable glycaemic control with basal insulin alone, or in combination with a single prandial insulin injection. The addition of a single prandial insulin injection at the largest meal is well tolerated and associated with significant improvements in glycated haemoglobin (HbA(1c)), low rates of hypoglycaemia and limited weight gain. More people achieve recommended HbA(1c) targets with a basal-plus strategy, compared with twice-daily premixed insulin therapy, with lower rates of hypoglycaemia. The data indicate that a step-by-step approach with the basal-plus strategy is a promising alternative method of insulin intensification that allows for individualization of treatment and may delay progression to a full basal-bolus insulin replacement therapy for many individuals.

Modified release terbutaline (SKP1052) for hypoglycaemia prevention: a proof-of-concept study in people with type 1 diabetes mellitus

AIMS

In this randomized, single blind, cross-over study 2.5 mg and 5 mg of the modified-release terbutaline formulation (SKP-1052) were compared with conventional immediate-release terbutaline (IRT, 5 mg) and placebo on overnight blood glucose (BG) and hypoglycaemia in 30 subjects with type 1 diabetes mellitus.

METHODS

Subjects received subcutaneous injections of insulin glargine (individualized doses) before dinner. SKP-1052, IRT or placebo was administered around 21:00 hours. BG and terbutaline concentrations were monitored overnight for 10 h post-dosing. Endpoints comprised of the nadir BG (BGn 0-10 h, primary endpoint), mean overnight BG (BGmean), morning BG (BGmorning) and hypoglycaemia rates as well as pharmacokinetic (PK) endpoints.

RESULTS

SKP-1052 delayed release of terbutaline by 2 h [PK-tmax (mean ± SD) 5.0 ± 2.1 h (2.5 mg) and 4.7 ± 1.7 h (5 mg) vs. 2.6 ± 1.3 h with IRT, p < 0.01, respectively]. Compared with placebo, no significant differences were observed for BGn 0-10 h across treatments, but both 5 mg formulations showed less hypoglycaemic events [10 (IRT), 16 (SKP-1052) vs. 33], higher BGmean (120, 114 and 95 mg/dl) and BGmorning (126, 126 and 101 mg/dl, all comparisons p < 0.05 vs. placebo). Numerically higher BG-levels between 3 and 8 h post-dosing were observed with 2.5 mg SKP-1052 vs. placebo.

CONCLUSIONS

Compared with IRT SKP-1052 delays release of terbutaline. 2.5 mg SKP-1052 led to numerically higher BG 3 to 8 h post-dose without fasting hyperglycaemia while 5 mg SKP-1052 resulted in fasting hyperglycaemia vs. placebo. Future studies will investigate optimized doses of SKP-1052 for nocturnal hypoglycaemia prevention.

Long-term safety and efficacy of linagliptin as monotherapy or in combination with other oral glucose-lowering agents in 2121 subjects with type 2 diabetes: up to 2 years exposure in 24-week phase III trials followed by a 78-week open-label extension

Aim:  The aim of this study was to evaluate the long-term safety, tolerability and efficacy of the dipeptidyl peptidase-4 inhibitor linagliptin given either alone or in combination with other oral glucose-lowering agents in persons with type 2 diabetes. Methods:  A 78-week open-label extension study evaluated subjects who participated in one of four preceding 24-week, randomised, double-blind, placebo-controlled parent trials and who received linagliptin, linagliptin + metformin, linagliptin + metformin + a sulphonylurea or linagliptin + pioglitazone (all with linagliptin administered orally once daily). Individuals receiving one of these treatments during a previous trial continued the same treatment (n = 1532) for up to a total of 102 weeks, whereas those previously receiving placebo were switched to linagliptin (n = 589). All 2121 participants received at least one dose of the trial medication and were included in the primary safety analysis. Results:  In subjects previously receiving active treatment, the glycosylated haemoglobin A(1c) reduction achieved during the 24-week parent trials was sustained through the 78-week extension period (change from baseline to week 102: -0.8%). Drug-related adverse events were experienced by 14.3% of participants. Hypoglycaemia occurred in 13.9% of participants and was similar between those previously receiving treatment (13.6%) and those switching from placebo to linagliptin (14.6%). Hypoglycaemia occurred most frequently with the use of metformin + a sulphonylurea background therapy (11%). Overall, no clinically relevant changes in body weight were observed. Conclusion:  Long-term treatment with linagliptin was well tolerated with no change in the safety profile observed during the extension study. Sustained long-term glycaemic control was maintained for up to 102 weeks with either linagliptin monotherapy or linagliptin in combination with other oral glucose-lowering agents.

Diabetic retinopathy screening: perspectives of people with diabetes, screening intervals and costs of attending screening

AIMS

To obtain the views of people with diabetes about the provision of diabetic retinopathy screening services; and the interval of screening.

METHODS

Between October 2009 and January 2010, people with diabetes attending diabetic retinopathy screening clinics across Wales were asked to complete a questionnaire comprising of two parts: the first asking about their health, diabetes history, demographic characteristics and views about the diabetic retinopathy screening service, and the second asking about the costs of attending the screening.

RESULTS

The response rate was 40% (n = 621) from 1550 questionnaires distributed at diabetic retinopathy clinics, with 600 complete responses analysed. Respondents had a mean known duration of diabetes of 8.5 years (sd 7.8) and had attended for screening on average 3.2 times (sd 1.6) in the last 5 years. Sixty-eight per cent (n = 408) of respondents reported having their eyes screened approximately once a year. Eighty-five per cent (n = 507) felt that they should have their eyes screened every year. However, 65% (n = 390) of respondents would accept screening at 2- or 3-year intervals if medical evidence showed that it was safe. The reported personal costs incurred by respondents attending diabetic retinopathy screening were low.

CONCLUSION

Our study suggests that people with diabetes undergoing diabetic retinopathy screening would accept a greater screening interval, provided that adequate clinical evidence and medical reassurance were given.

Preferences of people with diabetes for diabetic retinopathy screening: a discrete choice experiment

AIMS

The ever-increasing prevalence of diabetes places pressure on the provision of diabetic retinopathy screening services. As the first study of its kind, we aimed to determine preferences for diabetic retinopathy screening in people with diabetes and to examine the trade-offs between frequency of screening and other service attributes.

METHODS

A questionnaire including a discrete choice experiment was administered to people (n = 198) attending diabetic retinopathy screening at eight clinics across Wales, United Kingdom. The discrete choice experiment contained eight pairwise choices in which screening provision was described by five attributes: frequency of screening; travel time; results time; ability of screening to detect other changes; and explanation of results. Data were analysed using logistic regression techniques.

RESULTS

We gained a response rate of 86.4% from the 198 questionnaires administered at clinics; 160 complete responses were analysed. Respondents valued four out of the five attributes [ability of screening to detect other changes (P = 0.000), explanation of results (P = 0.024), frequency of screening (P = 0.000) and travel time (P = 0.007)]. Results time was insignificant (P = 0.122). Respondents were willing to wait an additional 12, 2 and 1 month between screening tests to have a test that was able to detect additional changes, to have their results explained in person rather than by letter and to have a 15-min reduction in travel time, respectively.

CONCLUSIONS

Respondents were willing to accept a longer screening interval, as long as preferences for other attributes of service provision (ability of screening to detect other changes, explanation of results and travel time) were made available.

Paediatric nutrition risk scores in clinical practice: children with inflammatory bowel disease

BACKGROUND

There has been increasing interest in the use of nutrition risk assessment tools in paediatrics to identify those who need nutrition support. Four non-disease specific screening tools have been developed, although there is a paucity of data on their application in clinical practice and the degree of inter-tool agreement.

METHODS

The concurrent validity of four nutrition screening tools [Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP), Screening Tool for Risk On Nutritional status and Growth (STRONGkids), Paediatric Yorkhill Malnutrition Score (PYMS) and Simple Paediatric Nutrition Risk Score (PNRS)] was examined in 46 children with inflammatory bowel disease. Degree of malnutrition was determined by anthropometry alone using World Health Organization International Classification of Diseases (ICD-10) criteria.

RESULTS

There was good agreement between STAMP, STRONGkids and PNRS (kappa > 0.6) but there was only modest agreement between PYMS and the other scores (kappa = 0.3). No children scored low risk with STAMP, STRONGkids or PNRS; however, 23 children scored low risk with PYMS. There was no agreement between the risk tools and the degree of malnutrition based on anthropometric data (kappa < 0.1). Three children had anthropometry consistent with malnutrition and these were all scored high risk. Four children had body mass index SD scores < -2, one of which was scored at low nutrition risk.

CONCLUSIONS

The relevance of nutrition screening tools for children with chronic disease is unclear. In addition, there is the potential to under recognise nutritional impairment (and therefore nutritional risk) in children with inflammatory bowel disease.

Ten-year experience of home parenteral nutrition in a single centre

AIM

Recent data are scarce on the provision of home parenteral nutrition (HPN) in children from the UK but would help to commission intestinal failure services. Our aim was to describe 10 years of HPN experience in our centre, which serves a population of 650,000 children.

METHODS

Outcome and complication data were collected retrospectively from hospital records of children receiving HPN from April 2001. Data from other centres were used to compare complications and outcomes in the provision of HPN.

RESULTS

Nineteen children (12 females) received 10,213 days (28 years) of HPN. In this group, incidence of blood culture positive sepsis was four episodes/1000 days PN. Two children had early intestinal failure-associated liver disease. Of the 19, seven still receive HPN at our centre, six survived PN, three were transferred to other services while still on HPN and three died.

CONCLUSION

Outcome and complication data for HPN from a single UK regional paediatric centre are similar to larger centres. These data provide recent evidence of the disease burden of HPN, which are important for the commissioning of intestinal failure services.

Incidence of diabetic retinopathy in people with type 2 diabetes mellitus attending the Diabetic Retinopathy Screening Service for Wales: retrospective analysis

OBJECTIVES

To determine the incidence of any and referable diabetic retinopathy in people with type 2 diabetes mellitus attending an annual screening service for retinopathy and whose first screening episode indicated no evidence of retinopathy.

DESIGN

Retrospective four year analysis.

SETTING

Screenings at the community based Diabetic Retinopathy Screening Service for Wales, United Kingdom.

PARTICIPANTS

57,199 people with type 2 diabetes mellitus, who were diagnosed at age 30 years or older and who had no evidence of diabetic retinopathy at their first screening event between 2005 and 2009. 49,763 (87%) had at least one further screening event within the study period and were included in the analysis.

MAIN OUTCOME MEASURES

Annual incidence and cumulative incidence after four years of any and referable diabetic retinopathy. Relations between available putative risk factors and the onset and progression of retinopathy.

RESULTS

Cumulative incidence of any and referable retinopathy at four years was 360.27 and 11.64 per 1000 people, respectively. From the first to fourth year, the annual incidence of any retinopathy fell from 124.94 to 66.59 per 1000 people, compared with referable retinopathy, which increased slightly from 2.02 to 3.54 per 1000 people. Incidence of referable retinopathy was independently associated with known duration of diabetes, age at diagnosis, and use of insulin treatment. For participants needing insulin treatment with a duration of diabetes of 10 years or more, cumulative incidence of referable retinopathy at one and four years was 9.61 and 30.99 per 1000 people, respectively.

CONCLUSIONS

Our analysis supports the extension of the screening interval for people with type 2 diabetes mellitus beyond the currently recommended 12 months, with the possible exception of those with diabetes duration of 10 years or more and on insulin treatment.

Effects of initiation and titration of a single pre-prandial dose of insulin glulisine while continuing titrated insulin glargine in type 2 diabetes: a 6-month 'proof-of-concept' study

AIM

Stepwise intensification of insulin treatment to match the progressive decline of endogenous insulin secretion has been shown to be an effective management strategy in type 2 diabetes mellitus (T2DM). The efficacy of initiating and titrating a single bolus dose of insulin glulisine to baseline insulin glargine plus oral hypoglycaemic agents (OHAs) was investigated.

METHODS

This was a 6-month, parallel-group, randomized, open-label, Phase IV study conducted in the US, UK and Russia. People with T2DM (HbA(1c) 7.5-9.5%) using any basal insulin underwent a 3-month run-in period on insulin glargine titrated to optimize fasting blood glucose (BG) control. Those with HbA(1c) >7.0% were randomized to either continue prior therapy (n = 57) or to add a single dose of insulin glulisine (n = 49) immediately prior to the main meal for a further 3 months. Two different titration algorithms were employed for the bolus dose, targeting 2-h postprandial BG ≤135 mg/dL (≤7.5 mmol/l; Russia and UK) or pre-meal/bedtime BG 100-120 mg/dl (5.5-6.7 mmol/l; US).

RESULTS

HbA(1c) and fasting plasma glucose levels decreased during the run-in period. In the 3 months after randomization, more participants in the basal-plus-bolus group reached HbA(1c) <7.0% than the basal-only control group (22.4 vs. 8.8%; p < 0.05), with significantly greater reduction of HbA(1c) (-0.37 vs. -0.11%; p = 0.0290). Rates of hypoglycaemia and mean weight change were comparable between the treatment groups.

CONCLUSIONS

In people with T2DM inadequately controlled on basal insulin plus OHAs, adding a single injection of insulin glulisine prior to the main meal significantly improves glucose control without undesired side effects.

Efficacy and safety of linagliptin in persons with type 2 diabetes inadequately controlled by a combination of metformin and sulphonylurea: a 24-week randomized study

AIMS

To examine the efficacy and safety of the dipeptidyl peptidase-4 inhibitor linagliptin in persons with Type 2 diabetes mellitus inadequately controlled [HbA(1c) 53-86 mmol/mol (7.0-10.0%)] by metformin and sulphonylurea combination treatment.

METHODS

A multi-centre, 24-week, randomized, double-blind, parallel-group study in 1058 patients comparing linagliptin (5 mg once daily) and placebo when added to metformin plus sulphonylurea. The primary endpoint was the change in HbA(1c) after 24 weeks.

RESULTS

At week 24, the linagliptin placebo-corrected HbA(1c) adjusted mean change from baseline was -7 mmol/mol (-0.62%) [95% CI -8 to -6 mmol/mol (-0.73 to -0.50%); P < 0.0001]. More participants with baseline HbA(1c) ≥ 53 mmol/mol (≥ 7.0%) achieved an HbA(1c) < 53 mmol/mol (<7.0%) with linagliptin compared with placebo (29.2% vs. 8.1%, P< 0.0001). Fasting plasma glucose was reduced with linagliptin relative to placebo (-0.7 mmol/l, 95% CI -1.0 to -0.4; P<0.0001). Improvements in homeostasis model assessment of β-cell function were seen with linagliptin (P<0.001). The proportion of patients who reported a severe adverse event was low in both groups (linagliptin 2.4%; placebo 1.5%). Symptomatic hypoglycaemia occurred in 16.7 and 10.3% of the linagliptin and placebo groups, respectively. Hypoglycaemia was generally mild or moderate; severe hypoglycaemia was reported in 2.7 and 4.8% of the participants experiencing hypoglycaemic episodes in the linagliptin and placebo groups, respectively. No significant weight changes were noted.

CONCLUSIONS

In patients with Type 2 diabetes, adding linagliptin to metformin given in combination with a sulphonylurea significantly improved glycaemic control and this was well tolerated. Linagliptin could provide a valuable treatment option for individuals with inadequate glycaemic control despite ongoing combination therapy with metformin and a sulphonylurea.

Comparative pharmacodynamic and pharmacokinetic characteristics of subcutaneous insulin glulisine and insulin aspart prior to a standard meal in obese subjects with type 2 diabetes

AIMS

A multinational, randomized, double-blind, two-way crossover trial to compare the pharmacokinetic and pharmacodynamic properties of bolus, subcutaneously administered insulin glulisine (glulisine) and insulin aspart (aspart) in insulin-naÏve, obese subjects with type 2 diabetes.

METHODS

Thirty subjects [9/21 females/males; mean ± SD age: 60.7 ± 7.7 years; body mass index (BMI): 33.5 ± 3.3 kg/m(2) ; duration of diabetes: 6.8 ± 4.6 years; HbA1c: 7.1 ± 0.8%] were included in the analysis. They fasted overnight and then received a 0.2 U/kg subcutaneous dose of glulisine or aspart 2 min before starting a standardized test meal, 7 days apart, according to a randomization schedule. Blood samples were taken every 15 min, starting 20 min before the meal and ending 6 h postprandially.

RESULTS

The area under the absolute glucose concentration-time curve between 0 and 1 h after insulin injection and maximal glucose concentration was significantly lower with glulisine than with aspart (p = 0.0455 and 0.0337, respectively). However, for the total study period, plasma glucose concentration was similar for glulisine and aspart. Peak insulin concentration was significantly higher for glulisine than for insulin aspart (p < 0.0001). Hypoglycaemic events (≤ 70 mg/dl with or without symptoms) occurred in 13 and 16 subjects treated with glulisine and aspart, respectively, but there were no cases of severe hypoglycaemia requiring intervention.

CONCLUSIONS

Glulisine was associated with lower glucose levels during the first hour after a standard meal; the remaining glucose profiles were otherwise equivalent, with higher insulin levels observed throughout the study period.

A longitudinal study into the new and long-term use of self-monitoring blood glucose strips in the UK

AIMS

To determine the impact of self-monitoring blood glucose (SMBG) strip use in patients with type 2 diabetes in the UK.

METHODS

The study period was April 1, 2004 to July 31, 2005. Data from primary care was extracted from The Health Improvement Network database. Patients identified with diabetes and matching the inclusion criteria were defined as new users of SMBG, prevalent users, or non-users. Patients were also defined as treated with insulin, with oral agents (OA), or not pharmacologically treated. Change in glycosylated hemoglobin (HbA(1c)) at baseline and after 12 months was compared.

RESULTS

2559 patients met the inclusion criteria. For new users, HbA(1c) fell by 0.59% (P=0.399) for those treated with insulin, 1.52% (P<0.001) for those treated with OA, and 0.51% (P<0.001) for no treatment. In prevalent users, changes were 0.31% (P<0.001), 0.34% (P<0.001), and 0.09% (P=0.456), respectively. In non-users, changes were 0.28% (P=0.618), 0.42% (P<0.001), and an increase of 0.05% (P=0.043), respectively. A significant decrease in mean HbA(1c) was associated with increasing strip use in OA patients newly initiated on strips.

CONCLUSION

This observational study showed a significant decrease in HbA(1c) for new users of SMBG treated either non-pharmacologically or with OA, and for prevalent users treated with insulin or OA. Reduced HbA(1c) with increasing strip use was observed but was only significant for OA-treated new users. This suggests that SMBG use has a role in the treatment of non-insulin treated patients with type 2 diabetes.

Daytime variability of postprandial glucose tolerance and pancreatic B-cell function using 12-h profiles in persons with Type 2 diabetes

AIMS

To study the variation in daytime glucose tolerance and pancreatic B-cell function at different levels of glycated haemoglobin (HbA(1c)) in subjects with Type 2 diabetes (T2DM).

METHODS

T2DM subjects (n = 49; 34 men) had 12-h daytime plasma glucose (PG), insulin (PI), total (PTp) and intact proinsulin (PIp) profiles determined in response to three identical test meals at 4-h intervals. Subjects were divided into three groups according to HbA(1c)--group 1: < 7.3% (n = 18); group 2: 7.3-8.0% (n = 17); group 3: > 8.0% (n = 14). Fasting and preprandial (prior to meals 2 and 3) concentrations, total area under the curve (AUC), AUC above fasting (dAUC) and maximum postprandial metabolic concentrations (C(max)) were compared between the three meals and across the groups.

RESULTS

Subjects in group 1 had significantly higher fasting plasma glucose (FPG) compared with preprandial PG concentrations (7.1 +/- 0.2 vs. 5.9 +/- 0.3 vs. 5.4 +/- 0.2; P < 0.01). Subjects in groups 2 and 3 had significantly higher FPG compared with preprandial PG levels prior to meal 3. PG.dAUC was highest in response to meal 1 and lowest following meal 2 (P < 0.05). FPI concentrations were significantly lower compared with preprandial PI concentrations. Subjects in group 1 had significantly higher PI prior to meal 2 compared with meal 3. PI.dAUC was highest in response to meal 1. Subjects in group 1 had lowest PI.dAUC following meal 2. FTp and FIp concentrations were also significantly lower compared with preprandial concentrations. PTp.dAUC and PIp.dAUC was highest in response to meal 1.

CONCLUSIONS

There appears to be a shift in diurnal variation in glucose homeostasis and pancreatic B-cell function. Subjects had decreased glucose tolerance in response to the first and third meal of the day irrespective of glycaemic control. The variability in glucose tolerance was reflected by both quantitative and qualitative dysfunction of the pancreatic B-cell.

Regulation of oxidative stress by glycaemic control: evidence for an independent inhibitory effect of insulin therapy

AIMS/HYPOTHESIS

We examined whether type of diabetes and/or insulin treatment can modulate the impact of sustained hyperglycaemia and glycaemic variability as activators of oxidative stress.

METHODS

This was an observational study in 139 patients with diabetes, 48 with type 1, 60 with type 2 treated by oral hypoglycaemic agents (OHAs) alone and 31 with type 2 treated with insulin plus OHAs. In addition, two groups of ten patients with type 2 diabetes were investigated either before and after introducing insulin treatment (add-on insulin group) or before and after add-on OHA therapy to metformin (add-on OHA group). Oxidative stress was estimated from 24 h urinary excretion rates of 8-isoprostaglandin F2alpha (8-iso-PGF2alpha). HbA(1c) was assessed and mean amplitude of glycaemic excursions (MAGE) was estimated by continuous monitoring.

RESULTS

The 24 h excretion rate of 8-iso-PGF2alpha (median [range] picomoles per millimole of creatinine) was much higher (p < 0.0001) in type 2 diabetes patients treated with OHAs alone (112 [26-329]) than in the type 1 diabetes group (65 [29-193]) and the type 2 diabetes group treated with insulin (69 [30-198]). It was associated with HbA(1c) (F = 12.9, p = 0.0008) and MAGE (F = 7.7, p = 0.008) in non-insulin-treated, but not in insulin-treated patients. A significant reduction in 24 h excretion rate of 8-iso-PGF2alpha from 126 (47-248) to 62 (35-111] pmol/mmol of creatinine was observed in the add-on insulin group (p = 0.005) but not in the add-on OHA group.

CONCLUSIONS/INTERPRETATION

In type 1 and type 2 diabetes, insulin exerts an inhibitory effect on oxidative stress, a metabolic disorder that is significantly activated by sustained hyperglycaemia and glucose variability in non-insulin-treated type 2 diabetes.

The glucose lowering effect of an oral insulin (Capsulin) during an isoglycaemic clamp study in persons with type 2 diabetes

AIM

Randomized, open, single-centre, two-way crossover study comparing the pharmacokinetic (PK) and pharmacodynamic (PD) properties of subcutaneous (sc) regular human insulin (Actrapid) and oral insulin in a capsule form (Capsulin).

METHODS

Sixteen persons (12 males) with type 2 diabetes on oral hypoglycaemic agents (OHAs) participated. Mean (s.d.) age 60.2 (5.5) years, BMI 28.3 (3.4) kg/m(2), haemoglobin A(1c) (HbA(1c)) 7.4% (1.1). Two 6-h isoglycaemic glucose clamp studies were conducted 11 days apart. All subjects received in random order 12U sc Actrapid on one clamp study day and either 150U or 300U Capsulin (Cap) on the other day. Glucose infusion rates (GIRs), plasma insulin and C-peptide concentrations were determined throughout each 6-h isoglycaemic clamp. Between the clamp study days, all patients received 150U Capsulin twice daily, dropping all their standard OHAs apart from metformin. Self-monitored blood glucose (SMBG) levels were taken four times a day between the clamp study days.

RESULTS

Administration of either Actrapid or Capsulin (150 and 300U) increased GIRs reaching a maximum values at approximately 280-330 min. Overall values for maximum GIR values were higher for Actrapid than either dose of Capsulin (p < 0.05). The significantly greater systemic insulin concentrations following Actrapid were reflected in the AUC(0-6 h) (910 +/- 270 vs. 472 +/- 245 pmol h/L; 950 +/- 446 vs. 433 +/- 218 pmol h/L; both p < 0.05 for Actrapid vs. 150U Capsulin and 300U Capsulin respectively). No difference was observed between 150U and 300U Capsulin. During the repeat-dosing period, good safety and tolerability were observed with Capsulin, and SMBG levels remained stable. At the poststudy visit, significant falls in HbA(1c), weight and triglycerides were observed.

CONCLUSIONS

Administration of the oral insulin Capsulin preparation demonstrated a significant hypoglycaemic action over a period of 6 h associated with only a small increase in circulating plasma insulin concentrations.

Relative and absolute contributions of postprandial and fasting plasma glucose to daytime hyperglycaemia and HbA(1c) in subjects with Type 2 diabetes

AIMS

To determine the relative and absolute contributions of postprandial glucose (PPG) and fasting or preprandial plasma glucose (FPG) to daytime hyperglycaemia and HbA(1c) respectively, in persons with type 2 diabetes (T2DM).

METHODS

Subjects (n = 52; 37 men) had 12hr plasma glucose (PG) profiles determined in response to three serial identical test meals. PPG exposure was calculated for each meal. Excess hyperglycaemia was calculated above a PG concentration of 5.5 mmol/l. Fasting hyperglycaemia was the difference between excess hyperglycaemia and PPG exposure. Subjects were divided into three groups according to HbA(1c)-(Gp1:<7.3%;Gp2:7.3%-8.0%;Gp3:>8.0%) and the relative contribution of PPG exposure and fasting hyperglycaemia to excess hyperglycaemia calculated for each meal. The absolute contribution of PPG and fasting hyperglycaemia to excess HbA(1c) (mean HbA(1c)-5.1%) was also calculated.

RESULTS

The relative contributions of PPG exposure to excess hyperglycaemia for the three groups were: 58.3%, 54.3% and 35.4% (P = 0.483-Group 1 vs. Group 2; P = 0.002-Group 2 vs. Group 3) for meal 1; 69.8%, 54.7% and 23.7% (P = 0.163-Group 1 vs. Group 2; P = 0.005-Group 2 vs. Group 3) for meal 2; 85.8%, 70.2% and 48.6% (P = 0.153-Group 1 vs. Group 2; P = 0.046-Group 2 vs. Group 3) for meal 3. Absolute contributions of PPG to excess HbA(1c) in the three groups were 1.4%, 1.6% and 1.3% (P = NS).

CONCLUSION

The relative contribution of postprandial glucose to excess hyperglycaemia decreases as glycaemic control deteriorates, being dominant with HbA(1c)</= 7.3%, irrespective of the timing of the meal during the day. However, the absolute contribution of postprandial glucose to excess HbA(1c) does not differ significantly ( approximately 1.5%) with varying glycaemic control.

Use of cystatin C-based estimations of glomerular filtration rate in patients with type 2 diabetes

AIMS/HYPOTHESIS

The Modification of Diet in Renal Disease (MDRD) equation has recognised limitations when using estimated GFR in persons at risk of chronic kidney disease. Equations based on cystatin C provide an alternative method. We compared performance of the MDRD equation with a selection of cystatin C-based formulae for estimation of GFR in normoalbuminuric patients with type 2 diabetes.

METHODS

Estimated GFR was calculated using the MDRD equation and the cystatin C formulae proposed by several investigator teams. Isotopic GFR was measured using plasma clearance of (51)Cr-EDTA.

RESULTS

We studied 106 participants, of whom 83 (78%) were men with the following characteristics, mean (SD): age 61 (9) years, HbA(1c) 7.10 (1.27)%, creatinine 89.0 (12.7) micromol/l, cystatin C 0.859 (0.234) mg/l and isotopic GFR 104.5 (20.1) ml min(-1) 1.73 m(-2). MDRD estimated GFR was 77.4 (13.6) ml min(-1) 1.73 m(-2) (p < 0.05 for difference from isotopic GFR). Cystatin C-based calculations of estimated GFR were: Perkins 124.5 (31.8), Rule 90.0 (30.0), Stevens (age) 96.0 (30.4) and Stevens (creatinine) 85.6 (19.0) ml min(-1) 1.73 m(-2) (p < 0.05 for difference with isotopic GFR). For Arnal's, MacIsaac's and Tan's formulae cystatin-C estimated GFR were 101.7 (34.8), 102.1 (27.0) and 101.6 (27.8) ml min(-1) 1.73 m(-2), respectively (p = NS for difference with isotopic GFR). Cystatin C-based formulae were less biased and, with the exception of Perkins' formula, more accurate to within 10% of isotopic GFR than MDRD.

CONCLUSIONS/INTERPRETATION

Performance of cystatin C equations was superior to MDRD in normoalbuminuric patients with type 2 diabetes. These results support further evaluation of cystatin C for estimation of GFR in persons at risk of chronic kidney disease.

Beyond the era of NPH insulin--long-acting insulin analogs: chemistry, comparative pharmacology, and clinical application

The new rDNA and DNA-derived "basal" insulin analogs, glargine and detemir, represent significant advancement in the treatment of diabetes compared with conventional NPH insulin. This review describes blood glucose homeostasis by insulin in people without diabetes and outlines the physiological application of exogenous insulin in patients with type 1 and type 2 diabetes. The requirements for optimal basal insulin treatment are discussed and the methods used in the evaluation of basal insulins are presented. An essential criterion in the development of an "ideal" basal insulin preparation is that the molecular modifications made to the human insulin molecule do not compromise safety. It is also necessary to obtain a clear understanding of the pharmacokinetic and pharmacodynamic characteristics of the two currently available basal insulin analogs. When comparing glargine and detemir, the different molar concentration ratios of the two insulin formulations should be considered along with the nonspecificity of assay systems used to determine insulin concentrations. However, euglycemic clamp studies in crossover study design provide a good basis for comparing the pharmacodynamic responses. When the latter is analyzed by results of intervention clinical trials, it is concluded that both glargine and detemir are superior to NPH in type 1 and type 2 diabetes. However, there is sufficient evidence to demonstrate that these two long-acting insulin analogs are different in both their pharmacokinetic and pharmacodynamic profiles. These differences should be taken into consideration when the individual analogs are introduced to provide basal insulin supplementation to optimize blood glucose control in patients with type 1 and type 2 diabetes as well. PubMed-Medline was searched for articles relating to pharmacokinetics and pharmacodynamics of glargine and detemir. Articles retrieved were reviewed and selected for inclusion if (1) the euglycemic clamp method was used with a duration >or=24 h, (2) a single subcutaneous dose of glargine/detemir was used, and (3) area under the curve for insulin concentrations or glucose infusion rates were calculated.

Performance of the revised '175' Modification of Diet in Renal Disease equation in patients with type 2 diabetes

AIMS/HYPOTHESIS

Estimation of GFR (eGFR) is recommended for the assessment of kidney function in all patients with diabetes. We studied performance of the traditional '186' Modification of Diet in Renal Disease (MDRD) equation, and the 2005 revised '175' MDRD equation in patients with type 2 diabetes.

METHODS

Two hundred and ninety-three mainly normoalbuminuric (267/293) patients were recruited. Patients were classified as having mild renal impairment (group 1, GFR <90 ml min(-1) 1.73 m(-2)) or normal renal function (group 2, GFR >or=90 ml min(-1) 1.73 m(-2)). eGFR was calculated by the traditional 186 MDRD equation using traditional creatinine values and the revised 175 MDRD equation using isotope dilution mass spectrometry-standardised creatinine values. Isotopic GFR was measured by the four-sample plasma clearance of (51)Cr-EDTA.

RESULTS

For patients in group 1, mean +/- SD isotopic (51)Cr-EDTA GFR (iGFR) was 83.8 +/- 4.3 ml min(-1) 1.73 m(-2), and eGFR was 73.2 +/- 11.9 and 75.8 +/- 13.7 ml min(-1) 1.73 m(-2) using the 186 and 175 MDRD equations, respectively. Method bias was -10.6 with the 186 MDRD and -7.9 ml min(-1) 1.73 m(-2) (p < 0.05) with the 175 MDRD equation. In group 2, iGFR was 119.4 +/- 20.2 ml min(-1) 1.73 m(-2), and eGFR was 92.3 +/- 18.6 and 97.5 +/- 21.6 ml min(-1) 1.73 m(-2) using the 186 and 175 MDRD equations, respectively. Method bias was -27.1 with the 186 MDRD equation and -21.9 ml min(-1) 1.73 m(-2) (p < 0.05) with the 175 MDRD equation.

CONCLUSIONS/INTERPRETATION

In patients newly diagnosed with type 2 diabetes, the revised 175 MDRD equation was less biased than the traditional 186 MDRD equation. Despite a continued tendency to underestimate isotopically measured GFR, use of standardised creatinine values is a positive step towards improved estimation of GFR.

Insulin resistance and inflammation - A further systemic complication of COPD

Chronic obstructive pulmonary disease (COPD) is associated with a continuous systemic inflammatory response. Furthermore, COPD is associated with an excess risk for cardiovascular disease and type II diabetes. Systemic inflammation in other populations is a factor in atherogenesis and has been associated with insulin resistance. We assessed the association between systemic inflammation and insulin resistance in non-hypoxaemic patients with COPD. Fasting plasma glucose, insulin and inflammatory mediators were measured in 56 patients and 29 healthy subjects. Body mass index (BMI) and height squared fat- and fat-free-mass index were similar between subject groups. Using homeostatic modelling techniques, mean (SD) insulin resistance was greater in the patients, 1.68 (2.58) and 1.13 (2.02) in healthy subjects, p=0.032. Fasting plasma insulin was increased in patients while glucose was similar to that in healthy subjects. Patients had increased circulating inflammatory mediators. Insulin resistance was related to interleukin-6 (IL-6), r=0.276, p=0.039, and tumour necrosis factor alpha soluble receptor I, r=0.351, p=0.008. Both IL-6 and BMI were predictive variables of insulin resistance r(2)=0.288, p<0.05. We demonstrated greater insulin resistance in non-hypoxaemic patients with COPD compared with healthy subjects, which was related to systemic inflammation. This relationship may indicate a contributory factor in the excess risk of cardiovascular disease and type II diabetes in COPD.

Results of the pilot study of DIADEM: a comprehensive disease management programme for type 2 diabetes

AIMS

The purpose of the study was to evaluate the feasibility and preliminary clinical effects of the DIADEM disease management programme for type 2 diabetic patients.

METHODS

The study was performed at two test sites (Cardiff, UK: Aachen, Germany) including 137 and 166 patients, respectively. In 16 study centres any patients with type 2 diabetes capable of communicating by phone and able to perform blood pressure, blood glucose or urine glucose self-measurements were included. The maximum programme duration was 6 months at Cardiff and 4 months at Aachen, during which patients were assessed for glycaemic control, cardiovascular risk profile and the presence of complications of diabetes. Data were entered via the internet to a central server.

RESULTS

At entry into the programme the patient group in Cardiff had significantly lower mean age (60.3+/-9.4 years versus 64.9+/-8.7 years, p<0.001) and duration of diabetes (6.1+/-5.7 years versus 7.4+/-7.0 years, p<0.05) than in Aachen, however body mass index (31.6+/-5.2 kg/m(2) versus 29.5+/-4.9 kg/m(2), p<0.01), HbA1c (7.7+/-1.2% versus 7.1+/-1.2%, p<0.001) and systolic blood pressure (138.4+/-15.1 mmHg versus 133.5+/-11.5 mmHg, p<0.001) were significantly higher. In contrast, total cholesterol (4.7+/-1.0 mmol/l versus 5.5+/-1.1 mmol/l, p<0.001) was significantly lower in Cardiff compared to Aachen. Following entry into the programme highly significant improvements in HbA1c (Cardiff from 7.7% to 7.1%, p<0.001; Aachen from 7.2% to 6.8%, p<0.05) and total cholesterol concentrations (Cardiff: 4.66-4.46 mmol/l; Aachen: 5.33-5.15 mmol/l; both p<0.05) were observed. There were no significant changes in blood pressure at either site.

CONCLUSIONS

Intensive diabetes care was delivered to DIADEM patients and relevant and significant improvements in diabetes care were achieved demonstrating that an IT-based diabetes disease management service can improve care for patients with type 2 diabetes.