Population-Level Impact and Cost-effectiveness of Continuous Glucose Monitoring and Intermittently Scanned Continuous Glucose Monitoring Technologies for Adults With Type 1 Diabetes in Canada: A Modeling Study

OBJECTIVE

Maintaining healthy glucose levels is critical for the management of type 1 diabetes (T1D), but the most efficacious and cost-effective approach (capillary self-monitoring of blood glucose [SMBG] or continuous [CGM] or intermittently scanned [isCGM] glucose monitoring) is not clear. We modeled the population-level impact of these three glucose monitoring systems on diabetes-related complications, mortality, and cost-effectiveness in adults with T1D in Canada.

RESEARCH DESIGN AND METHODS

We used a Markov cost-effectiveness model based on nine complication states for adults aged 18-64 years with T1D. We performed the cost-effectiveness analysis from a single-payer health care system perspective over a 20-year horizon, assuming a willingness-to-pay threshold of CAD 50,000 per quality-adjusted life-year (QALY). Primary outcomes were the number of complications and deaths and the incremental cost-effectiveness ratio (ICER) of CGM and isCGM relative to SMBG.

RESULTS

An initial cohort of 180,000 with baseline HbA1c of 8.1% was used to represent all Canadians aged 18-64 years with T1D. Universal SMBG use was associated with ∼11,200 people (6.2%) living without complications and ∼89,400 (49.7%) deaths after 20 years. Universal CGM use was associated with an additional ∼7,400 (4.1%) people living complications free and ∼11,500 (6.4%) fewer deaths compared with SMBG, while universal isCGM use was associated with ∼3,400 (1.9%) more people living complications free and ∼4,600 (2.6%) fewer deaths. Relative to SMBG, CGM and isCGM had ICERs of CAD 35,017/QALY and 17,488/QALY, respectively.

CONCLUSIONS

Universal use of CGM or isCGM in the Canadian T1D population is anticipated to reduce diabetes-related complications and mortality at an acceptable cost-effectiveness threshold.

Assessing Mealtime Macronutrient Content: Patient Perceptions Versus Expert Analyses via a Novel Phone App

Background: People with type 1 diabetes estimate meal carbohydrate content to accurately dose insulin, yet, protein and fat content of meals also influences postprandial glycemia. We examined accuracy of macronutrient content estimation via a novel phone app. Participant estimates were compared with expert nutrition analyses performed via the Remote Food Photography Method© (RFPM©). Methods: Data were collected through a novel phone app. Participants were asked to take photos of meals/snacks on the day of and day after scheduled exercise, enter carbohydrate estimates, and categorize meals as low, typical, or high protein and fat. Glycemia was measured via continuous glucose monitoring. Results: Participants (n = 48) were 15-68 years (34 ± 14 years); 40% were female. The phone app plus RFPM© analysis captured 88% ± 29% of participants' estimated total energy expenditure. The majority (70%) of both low-protein and low-fat meals were accurately classified. Only 22% of high-protein meals and 17% of high-fat meals were accurately classified. Forty-nine percent of meals with <30 g of carbohydrates were overestimated by an average of 25.7 ± 17.2 g. The majority (64%) of large carbohydrate meals (≥60 g) were underestimated by an average of 53.6 ± 33.8 g. Glycemic response to large carbohydrate meals was similar between participants who underestimated or overestimated carbohydrate content, suggesting that factors beyond carbohydrate counting may impact postprandial glycemic response. Conclusions: Accurate estimation of total macronutrients in meals could be leveraged to improve insulin decision support tools and closed loop insulin delivery systems; development of tools to improve macronutrient estimation skills should be considered.

Acute glycaemic management before, during and after exercise for cardiac rehabilitation participants with diabetes mellitus: a joint statement of the British and Canadian Associations of Cardiovascular Prevention and Rehabilitation, the International Council for Cardiovascular Prevention and Rehabilitation and the British Association of Sport and Exercise Sciences

Type 1 (T1) and type 2 (T2) diabetes mellitus (DM) are significant precursors and comorbidities to cardiovascular disease and prevalence of both types is still rising globally. Currently,~25% of participants (and rising) attending cardiac rehabilitation in Europe, North America and Australia have been reported to have DM (>90% have T2DM). While there is some debate over whether improving glycaemic control in those with heart disease can independently improve future cardiovascular health-related outcomes, for the individual patient whose blood glucose is well controlled, it can aid the exercise programme in being more efficacious. Good glycaemic management not only helps to mitigate the risk of acute glycaemic events during exercising, it also aids in achieving the requisite physiological and psycho-social aims of the exercise component of cardiac rehabilitation (CR). These benefits are strongly associated with effective behaviour change, including increased enjoyment, adherence and self-efficacy. It is known that CR participants with DM have lower uptake and adherence rates compared with those without DM. This expert statement provides CR practitioners with nine recommendations aimed to aid in the participant's improved blood glucose control before, during and after exercise so as to prevent the risk of glycaemic events that could mitigate their beneficial participation.

MON-LB115 Ready-To-Use Glucagon for the Prevention of Exercise-Induced Hypoglycemia in a Clinical Research Setting

OBJECTIVE: A mini-dose of a novel ready-to-use liquid stable glucagon (RTUG; Xeris Pharmaceuticals) was evaluated for the prevention of exercise-induced hypoglycemia (EIH) during and after moderate-to-high intensity aerobic exercise, in both a clinical research center (CRC) and outpatient setting. The observations from the CRC setting are reported here.

METHOD: A Phase 2 randomized, placebo-controlled, double-blind, two-treatment, crossover study enrolled 48 adults with Type 1 diabetes (T1D) treated with continuous subcutaneous insulin infusion, to evaluate the efficacy of pre-exercise RTUG in addition to standard of care basal insulin rate reduction. The CRC setting included 2 separate daytime exercise sessions 2 to 28 days apart. At 5 minutes prior to each exercise session, subjects reduced their basal rate of insulin infusion by 50% and self-administered placebo or RTUG 150 micrograms (μg) before performing 45 minutes of moderate-to-high intensity, aerobic exercise with a target of 80% maximum heart rate. Blood glucose was measured before, during, and after exercise to evaluate the incidence and severity of hypoglycemia.

RESULT: Of the 45 subjects (93.8%) that completed both exercise sessions in the CRC, EIH occurred more in placebo (n=8) compared to RTUG (n=1). More subjects used glucose tablets to treat EIH in placebo (n=4) compared to RTUG (n=1). Placebo-treated participants consumed 7-fold greater glucose tablets during and after exercise, and experienced more episodes of post-exercise hyperglycemia (blood glucose >250 mg/dL), compared to RTUG. Treatment emergent adverse events with RTUG were comparable to placebo. RTUG 150 μg caused no edema, erythema, nor injection site reactions. RTUG was safe and well tolerated and no serious adverse events occurred.

CONCLUSION:RTUG 150 μg adequately maintained euglycemia during and following prolonged, continuous, moderate-to-high intense aerobic exercise in the controlled CRC setting. When used prior to moderate-to-high intensity aerobic exercise, RTUG may reduce exercise-induced hypoglycemia in adults with T1D. These findings support the continued evaluation in the outpatient setting.

Differences between Pygmy and Non-Pygmy Hunting in Congo Basin Forests

We use data on game harvest from 60 Pygmy and non-Pygmy settlements in the Congo Basin forests to examine whether hunting patterns and prey profiles differ between the two hunter groups. For each group, we calculate hunted animal numbers and biomass available per inhabitant, P, per year (harvest rates) and killed per hunter, H, per year (extraction rates). We assess the impact of hunting of both hunter groups from estimates of numbers and biomass of prey species killed per square kilometre, and by examining the proportion of hunted taxa of low, medium and high population growth rates as a measure of their vulnerability to overhunting. We then map harvested biomass (kg-1P-1Yr-1) of bushmeat by Pygmies and non-Pygmies throughout the Congo Basin. Hunting patterns differ between Pygmies and non-Pygmies; Pygmies take larger and different prey and non-Pygmies sell more for profit. We show that non-Pygmies have a potentially more severe impact on prey populations than Pygmies. This is because non-Pygmies hunt a wider range of species, and twice as many animals are taken per square kilometre. Moreover, in non-Pygmy settlements there was a larger proportion of game taken of low population growth rate. Our harvest map shows that the non-Pygmy population may be responsible for 27 times more animals harvested than the Pygmy population. Such differences indicate that the intense competition that may arise from the more widespread commercial hunting by non-Pygmies is a far more important constraint and source of conflict than are protected areas.

Caspase activation is not required for villous cytotrophoblast fusion into syncytiotrophoblasts

The villous trophoblast renews itself by fusion of individual stem cells (cytotrophoblasts, CT) with a functional syncytium (syncytiotrophoblast, ST). The literature indicates that fusion occurs with limited activation (proteolytic cleavage) of caspase-8 in CT and is inhibited either by blocking caspase-8 synthesis or inhibiting activation with a caspase-8-specific inhibitor, zIETD. We challenge part of this evidence: inhibition of differentiation with caspase-8 inhibitors. Br-cAMP-stimulated differentiation of isolated CT into multinucleated syncytia in culture is not blocked with three different low molecular weight inhibitors of caspase-8: broad caspase inhibitors zVAD-fmk and qVD-OPh and the caspase-8-specific inhibitor zIETD-fmk. Syncytialization was determined by desmoplakin staining of intracellular boundaries surrounding >2 nuclei and by diffusion within fused cells of long-lived cytoplasmic staining from half of original CT to the unstained half. Differentiation of isolated CT into hCGβ-secreting syncytiotrophoblast was also not blocked by the inhibitors nor was upregulation of hCGβ secretion blocked in ST-stripped and regenerated 5 day explant cultures. The ratio of CT to ST nuclei present was also not changed in explant cultures by caspase inhibitors. The effectiveness of caspase inhibitors was demonstrated by their ability to completely block TNFα-induced apoptosis. We conclude that activation of caspases in general, and caspase-8 in particular, is not required for villous CT differentiation into ST. However, another role of intact caspase-8 (proform) in CT differentiation remains possible.

The aetiology, clinical presentations and outcome of febrile encephalopathy in children in Papua New Guinea

BACKGROUND

Febrile encephalopathy, defined as fever, seizures and/or altered consciousness, is a common presentation in children in tropical developing countries. Outcomes range from complete recovery through varying degrees of neurological disability which slowly resolve or remain permanent to death from either the acute illness or complications. Whilst bacterial meningitis accounts for a proportion of children affected, the aetiology in many remains unclear but includes malaria and probably viral encephalitis.

AIM

To understand the aetiology, presentation and outcome of febrile encephalopathy in children in Papua New Guinea.

METHODS

Children aged between 1 month and 12 years presenting to Port Moresby General Hospital with febrile encephalopathy were studied prospectively. A detailed history and examination and the following laboratory investigations were undertaken as appropriate: cerebrospinal fluid (CSF) microscopy and bacterial culture, gram stain, measurement of protein and glucose and latex agglutination testing for Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitides; Ziehl-Neelsen staining and india ink examination on selected samples; IgM for Japanese encephalitis, dengue, rubella and measles; PCR testing and mycobacterial culture for Mycobacterium tuberculosis. Blood was tested for flavivirus, measles and rubella IgM and IgG.

RESULTS

149 children were enrolled in the study. 129 had a lumbar puncture and CSF examination; 66 had a normal CSF white cell count. A clinical or laboratory-based diagnosis was possible for 140 children, but a definite pathogen was identifiable for only 55 (37%). The diagnoses included bacterial meningitis in 33 (S. pneumonia 16, H. influenza 13 and N. meningitides 4), tuberculous meningitis (5), probable tuberculous meningitis (18), malaria (10), cryptococcal meningitis (1), flavivirus encephalitis (5), rubella encephalitis (1), hepatic encephalopathy (1) and HIV encephalopathy (1). There were 28 cases of meningitis of unspecified aetiology. Of the five children with IgM-confirmed flavivirus encephalitis, one had dengue serotype 1 and two had Japanese encephalitis. Twenty-five children (including three of the five children with CSF flavivirus IgM) had serological IgG evidence of previous flavivirus infection. A history of multiple convulsions, the presence of neck stiffness and use of the Glasgow coma score (GCS) and TB score chart helped to identify children with bacterial meningitis and an adverse outcome and those with febrile convulsions.

CONCLUSION

The study confirms the importance of S. pneumonia and H. influenza as major causes of febrile encephalopathy in children in Papua New Guinea. Flaviviruses including Japanese encephalitis are a cause of the febrile encephalopathy syndrome, as is Mycobacterium tuberculosis. All children with febrile encephalopathy should have their GCS and TB scores recorded and should be examined for neck stiffness, and a history of the frequency of convulsions should be recorded. These basic clinical data can help to discriminate aetiology, to guide treatment and monitoring and to identify the children at highest risk of adverse outcome.

WHO criteria for measles elimination: a critique with reference to criteria for polio elimination

Smallpox was formally declared as eradicated in 1979. Smallpox is the only infectious disease of humans that has ever been eradicated. Poliomyelitis has been eliminated from three of the six World Health Organization (WHO) regions although not all countries within those regions always meet the elimination criteria. Elimination criteria for measles are being discussed. We use poliomyelitis and measles as examples to illustrate our assertion that the current approach to documenting measles elimination relies too heavily on criteria for surveillance quality, disadvantaging countries with long established and relatively inflexible surveillance systems. We propose an alternative approach to documenting measles elimination, with the two key criteria being molecular evidence to confirm the lack of a circulating endemic genotype for at least one year and maintenance of 95% coverage of one dose of measles-containing vaccine, with an opportunity for a second dose. Elimination status should be reviewed annually. We suggest four principles that should guide development of final criteria to document measles elimination: countries that have eliminated measles should be able to meet the elimination criteria; quality surveillance criteria are necessary but not sufficient to define elimination; quality surveillance criteria should be guided by elimination criteria, not the other way around; and elimination criteria should not differ between the WHO regions without good reason.

WHO criteria for measles elimination: a critique with reference to criteria for polio elimination

Smallpox was formally declared as eradicated in 1979. Smallpox is the only infectious disease of humans that has ever been eradicated. Poliomyelitis has been eliminated from three of the six World Health Organization (WHO) regions although not all countries within those regions always meet the elimination criteria. Elimination criteria for measles are being discussed. We use poliomyelitis and measles as examples to illustrate our assertion that the current approach to documenting measles elimination relies too heavily on criteria for surveillance quality, disadvantaging countries with long established and relatively inflexible surveillance systems. We propose an alternative approach to documenting measles elimination, with the two key criteria being molecular evidence to confirm the lack of a circulating endemic genotype for at least one year and maintenance of 95% coverage of one dose of measles-containing vaccine, with an opportunity for a second dose. Elimination status should be reviewed annually. We suggest four principles that should guide development of final criteria to document measles elimination: countries that have eliminated measles should be able to meet the elimination criteria; quality surveillance criteria are necessary but not sufficient to define elimination; quality surveillance criteria should be guided by elimination criteria, not the other way around; and elimination criteria should not differ between the WHO regions without good reason.

Exercise and glucose metabolism in persons with diabetes mellitus: perspectives on the role for continuous glucose monitoring

Exercise causes profound changes in glucose homeostasis. For people with type 1 diabetes, aerobic exercise usually causes blood glucose concentration to drop rapidly, while anaerobic exercise may cause it to rise, thereby making glycemic control challenging. Having the capacity to know their glucose levels and the direction of change during exercise increases self-efficacy in these persons who are prone to hypo- and hyperglycemia. For people with type 2 diabetes, learning first hand that regular exercise improves glucose levels may be a motivating factor in getting them to be more active. Continuous glucose monitoring is a potentially useful adjunct to diabetes management for the active person with either forms of diabetes. This review aims to guide the reader to use this technology to its maximum advantage by providing an overview of technical features, performance characteristics, and clinical utility, all balanced against the limitations that may be more prominent during physical activity.

Prevalence of Theileriosis in Red Hartebeest (Alcelaphus buselaphus caama) in Namibia

A total of 23 blood samples from Red Hartebeest and 28 ticks of the subspecies Rhipicephalus evertsi were collected in Namibia during the summer 2003. For a Piroplasmida species, Theileria sp 95.7% of blood and 50.0% of tick samples (all R. e. mimeticus, none of R. e. evertsi were carrying the pathogen) were PCR positive. Sequencing showed infection from a re-emerging mild species of Theileria phylogenetically different from other African Theileria species such as Theileria parva, T. buffeli, T. annulata, T. taurotragi or T. mutans.

Serological profile of sporadic acute viral hepatitis in an area of hyper-endemic hepatitis B virus infection

BACKGROUND

Located in the south western part of Saudi Arabia, the Gizan region is largely a rural community in which hepatitis B and chronic liver disease including hepatocellular carcinoma are highly prevalent.

AIM OF STUDY

To determine the relative frequencies of acute hepatitis A, B, C and E in acute viral hepatitis in an area of hyperendemic hepatitis B infection.

METHODS AND MATERIALS

In a prospective study 246 consecutive patients (179 males and 67 females) diagnosed in a 2-year period were tested for markers of Hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C (HCV) and hepatitis E virus (HEV).

RESULTS

Of the patients tested, 131 (53.3%) were children ( < 10 years), and 42 (17%) were 11 - 20 years in age. Ig M anti -HAV, IgM anti-HBV, anti- HCV and IgM anti-HEV were positive in 37%, 19.1%, 3.7% and 13.7% respectively. Markers of these viruses were absent in 24.4%. Among 131 children (< 10 years) the commonest cause of AVH was HAV occurring in 57.3% of the cases. In adults (> 21 years) HBV was found in 35.6% and IgM anti -HAV was detected in only 6.8%. In contrast to the age- related decline in the frequency of acute HA, the proportion of acute HE were similar in all age groups (13.7% in children, 16.7% in adolescents and 11.0% in adults).

CONCLUSION

The study indicated that HAV is still a common cause of AVH particularly among children in Gizan. Acute 1-113 had a low occurrence among the children, evidently as a consequence of the integration of HB vaccine into the Saudi Arabian national EPI, 10 years ago. With the availability of combined HB and HA vaccines, It should be possible to graft the vaccination against HAV on to the existing program in Saudi Arabia. Affecting 13.4% of the group studied, sporadic HEV constitute a significant cause of AVH in this population. Until HEV vaccine becomes widely available, its prevention would be mainly by the improvement of socio - economic and hygienic standards of the population.

Perception of social value predicts participation in school-based research

OBJECTIVE

To investigate factors affecting the participation of schools in a serosurvey.

METHODS

A telephone interview was conducted with a representative of 80 schools (response rate 92%). The schools had been randomly selected to participate in a seroprevalence survey evaluating a measles vaccination campaign of Victorian school-aged children in 1998.

RESULTS

Univariate analysis suggested that responses to the interview were not influenced by school level (primary/secondary), geographic location, funding source or participation in the seroprevalence survey. There was, however, a strong association of participation in the seroprevalence survey with the perception of value to students and the value to the community. Factor analysis identified two issues: the societal value and practical issues, which explained most of the variance in participation (pseudo R2 = 0.84).

CONCLUSION

The perception of the benefits of the study strongly influenced the decision by school representatives to participate in the seroprevalence survey.

IMPLICATIONS

Recruitment of schools for health-related research may be improved if the number of research projects in schools is monitored and possibly restricted, and the social value of the research is emphasised.

ELISA for IgG-class antibody to hepatitis E virus based on a highly conserved, conformational epitope expressed in Escherichia coli

In assays based on most recombinant hepatitis E virus (HEV) antigens, the IgG antibody responses to HEV are observed commonly to wane or disappear after the acute phase of infection. Such IgG assays have therefore been used for the diagnosis of acute HEV infection, but they have limited usefulness in seroepidemiological studies. Using western immunoblotting, it was shown previously that the open reading frame (ORF) 2.1 antigen, representing the carboxy-terminal 267 amino acids (aa) of the capsid protein, exposes a conformational epitope which allows optimal detection of convalescent antibody compared to other proteins expressed in Escherichia coli. This conformational epitope is shown to be highly conserved between divergent human HEV isolates, and the development of a sensitive and highly specific enzyme immunoassay (ELISA) based on this recombinant antigen is described. The ORF2.1 ELISA allows the detection and quantitation of both acute- and convalescent phase HEV-specific IgG, and will help to define better the antibody responses to the virus and the prevalence of HEV infection worldwide.

Washing and trypsin treatment of in vitro derived bovine embryos exposed to bovine viral diarrhea virus

Gametes, somatic cells and materials of animal origin in media are potential sources for introducing bovine viral diarrhea virus (BVDV) into systems for production of IVF bovine embryos. Further, the efficacy of washing and trypsin treatment for removal of BVDV from IVF embryos is questionable. Washing and trypsin treatments recommended by the International Embryo Transfer Society for in vivo-derived embryos were applied to in vitro-derived, virus-exposed, bovine embryos in this side-by-side comparison of treatments. Embryos for the study were produced in a virus-free system in which follicular oocytes were matured and fertilized in vitro and presumptive zygotes were co-cultured with bovine uterine tubal cells for 7 d. A total of 18 trials was performed, 9 using a noncytopathic BVDV and 9 using a cytopathic BVDV. In each trial, 4 equal groups of 10 or less, zona pellucida-intact embryos/ova were assembled, including 2 groups of morulae and blastocysts (M/B) and 2 groups of nonfertile or degenerated ova (NFD). Each group was prewashed and exposed to 10(4) to 10(6) TCID50/mL of either noncytopathic (SD-1) or cytopathic (NADL) BVDV for 2 h. Following in vitro viral exposure, one group of M/B and one group of NFD were washed. The other groups of M/B and NFD were trypsin-treated. Both treatments were consistent with IETS guidelines. After in vitro exposure to noncytopathic BVDV and washing, viral assays of 100% (9/9) and 78% (7/9) of the groups of M/B and NFD ova, respectively, were positive. After in vitro exposure to cytopathic BVDV and washing, viral assay of 33% (3/9) of the groups of both M/B and NFD ova were positive. After in vitro exposure to noncytopathic BVDV and trypsin treatment, viral assay of 44% (4/9) of groups of M/B and 67% (6/9) of groups of NFD ova were positive. Finally, after in vitro exposure to cytopathic BVDV and trypsin treatment, viral assay of 22% (2/9) of the groups of M/B and 44% (4/9) of the groups of NFD ova were positive. Contingency table analysis, in which data was stratified by embryo type and virus biotype, was used to compare results. While a difference existed between results of the 2 treatments of groups of M/B within the noncytopathic biotype (P = 0.01, Mantel Haenszel Chi-square), no difference was observed between comparison of treatment between all groups in both biotypes (P > 0.05).

Climate-related corrections for improved estimation of energy expenditure from heart rate in children

The purpose of this study was to determine the relationship between children's heart rate (HR) and climatic heat stress at several O2 uptake (Vo2) levels and to construct equations and nomograms for an improved estimation of energy expenditure (EE) from HR monitoring. On four occasions 12 boys and 8 girls (8-11 yr) cycled for 5 min each at 35, 55, and 75% of peak Vo2 (random order), with rest periods in between, in a climatic chamber. The randomly assigned conditions were 22 degrees C dry bulb temperature, 50% relative humidity (RH); 28 degrees C, 55% RH; 32 degrees C, 52% RH; or 35 degrees C, 58% RH. HR and Vo2 were determined during the final 2 min of rest and exercise bouts. HR measured at a dry bulb temperature (T) (HRmeas) was then related to a HR at 22 degrees C that would have been expected to occur at an identical Vo2 (HRcalc22) by using individual 22 degrees C HR-Vo2 regression lines. HRcalc22 could be estimated from HRmeas.[1.175032-(0.007956.T)], with a mean error of prediction for the entire group < 1.5 beats/min for each temperature. The following conclusions were drawn: 1) children's HR at a given Vo2 increases linearly with ambient temperature at 22-35 degrees C, 50-60% RH; and 2) HR can be corrected for the influence of climate in groups of children resting and exercising at the above conditions, thereby reducing the error of estimating EE from HR.