Vascular protection in people with diabetes

Comparison of the effects of triglyceride variability and exposure estimate on clinical prognosis in diabetic patients

BACKGROUND

Hypertriglyceridemia is an important feature of dyslipidemia in type 1 and type 2 diabetic patients and associated with the development of atherosclerotic cardiovascular disease. Recently, variability of lipid profile has been suggested as a residual risk factor for cardiovascular disease. This study compared the clinical impact of serum triglyceride variability, and their cumulative exposure estimates on cardiovascular prognosis in diabetic patients.

METHODS

A total of 25,933 diabetic patients who had serum triglyceride levels measured at least 3 times and did not have underlying malignancy, myocardial infarction (MI), and stroke during the initial 3 years (modeling phase) were selected from three tertiary hospitals. They were divided into a high/low group depending on their coefficient of variation (CV) and cumulative exposure estimate (CEE). Incidence of major adverse event (MAE), a composite of all-cause death, MI, and stroke during the following 5 years were compared between groups by multivariable analysis after propensity score matching.

RESULTS

Although there was a slight difference, both the high CV group and the high CEE group had a higher cardiovascular risk profile including male-dominance, smoking, alcohol, dyslipidemia, and chronic kidney disease compared to the low groups. After the propensity score matching, the high CV group showed higher MAE incidence compared to the low CV group (9.1% vs 7.7%, p = 0.01). In contrast, there was no significant difference of MAE incidence between the high CEE group and the low CEE group (8.6% vs 9.1%, p = 0.44). After the multivariable analysis with further adjustment for potential residual confounding factors, the high CV was suggested as an independent risk predictor for MAE (HR 1.19 [95% CI 1.03-1.37]).

CONCLUSION

Visit-to-visit variability of triglyceride rather than their cumulative exposure is more strongly related to the incidence of MAE in diabetic patients.

Analysis of Cardiovascular Hemodynamic and Autonomic Variables in Individuals with Systemic Arterial Hypertension, Type 2 Diabetes Mellitus, and Parkinson's Disease: A Comparative Study

BACKGROUND

Systemic arterial hypertension (SAH), type 2 diabetes mellitus (T2DM), and Parkinson's disease (PD) are highly prevalent chronic diseases that can significantly impact the cardiovascular system.

AIM

The aim of this study was to compare hemodynamic and autonomic variables at rest in individuals with SAH, T2DM, or PD.

METHODS

Fifty sedentary or insufficiently active individuals (22 men) with SAH (age = 66 ± 5.0 yr), T2DM (age = 52 ± 10 yr) or PD (age = 68 ± 8.0 yr) had their resting blood pressure (BP), arterial stiffness, endothelial function, and heart rate variability (HRV) assessed and compared.

RESULTS

Systolic and diastolic BP were higher in SAH (130 ± 10 / 80 ± 10 mmHg) than T2DM (110 ± 14 / 75 ± 11 mmHg) and PD, and (123 ± 20 / 70 ± 11 mmHg) respectively. T2DM individuals showed lower arterial stiffness (8.4 ± 1.1 m/s), when compared to SAH (10.3 ± 2.3 m/s) and PD (10.6 ± 3.0 m/s). T2DM had greater resting tachycardia showed by the mean RR (759 ± 79 ms), than SAH (962 ± 169 ms) and PD (976 ± 134 ms), which was accompanied by higher sympathetic modulation (low frequency [LF]: 62 ± 19 nu) and lower parasympathetic modulation (high frequency [HF]: 32 ± 16 nu) when compared to SAH (LF: 40 ± 16 nu; HF: 61 ± 33 nu). No differences among groups were found on non-linear HRV markers and endothelial reactivity indexes.

CONCLUSIONS

Individuals with T2DM showed impaired levels of cardiac autonomic markers when compared to individuals with SAH and PD, despite of having lower levels of BP and arterial stiffness.

Adults With Type 2 Diabetes Mellitus Exhibit a Greater Exercise-Induced Increase in Arterial Stiffness and Vessel Hemodynamics

Individuals with type 2 diabetes mellitus (T2DM) have a greater blood pressure (BP) response to acute maximal exercise compared to those without T2DM; however, whether they exhibit a different arterial stiffness response to maximal exercise has yet to be explored. Adults with (n=66) and without T2DM (n=61) underwent an arterial stress test: at rest and immediately postexercise, carotid-femoral pulse wave velocity, the gold standard measure of arterial stiffness, brachial BP, heart rate, and other hemodynamic measurements were assessed. Linear regression models were used to evaluate between-group differences at rest, and the response to exercise (postexercise value), adjusting for covariates including BP and heart rate when relevant, and the corresponding baseline value of each parameter. All participants (mean±SD: age 59.3±10.6 years; body mass index 31.2±3.9 kg/m 2 ) had hypertension (mean BP 130±14/80±9 mm Hg). At rest, participants with T2DM had significantly higher carotid-femoral pulse wave velocity (10.3±2.7 versus 9.1±1.9 m/s), heart rate (69±11 versus 66±10 beats/min), and lower diastolic BP (79±9 versus 83±9 mm Hg), but systolic BP (129±15 versus 131±13 mm Hg) was similar. In response to exercise, participants with T2DM showed greater increases in carotid-femoral pulse wave velocity (1.6 [95% CI, 0.4–2.9 m/s]) and systolic BP (9 [95% CI, 1–17 mm Hg]) than participants without T2DM. A greater proportion of participants with T2DM had a hypertensive response to exercise compared to participants without T2DM (n=23, 35% versus n=11, 18%; P =0.033). By incorporating exercise as a vascular stressor, we provide evidence of a greater increase in arterial stiffness in individuals with T2DM, independently of resting arterial stiffness, and the BP postexercise.

Impact of the diabetes Canada guideline dissemination strategy on dispensed vascular protective medications for older patients in Ontario, Canada: a linked EMR and administrative data study

BACKGROUND

The 2013 Diabetes Canada guidelines recommended routinely using vascular protective medications for most patients with diabetes. These medications included statins and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs). Antiplatelet agents were only recommended for secondary prevention of cardiovascular disease. Using Electronic Medical Record (EMR) data, we previously found that guideline dissemination efforts were not associated with an increase in the rate of primary care prescriptions of these medications. However, this needs confirmation: patients can receive prescriptions from different sources including specialists and they may not always fill these prescriptions. Using both EMR and administrative health data, we examined whether guideline dissemination impacted the dispensing of vascular protective medications to patients.

METHODS

The study population included patients with diabetes aged 66 or over in Ontario, Canada. We created two cohorts using two different approaches: an Electronic Medical Record (EMR) algorithm for diabetes using linked EMR-administrative data and an administrative algorithm using population level administrative data. We examined data from January 2010 to December 2016. Patients with diabetes were deemed to be likely taking a medication (or covered) during a quarter if the daily amount for a dispensed medication would last for at least 75% of days in any given quarter. An interrupted time series analysis was used to assess the proportion of patients covered by each medication class. Proton pump inhibitors (PPIs) were used as a reference.

RESULTS

There was no increase in the rate of change for medication coverage following guideline release in either the EMR or the administrative diabetes cohorts. For statins, the change in trend was - 0.03, p = 0.7 (EMR) and - 0.12, p = 0.04(administrative). For ACEI/ARBs, this was 0.03, p = 0.6 (EMR) and 0, p = 1(administrative). For antiplatelets, this was 0.001, P = .97 (EMR) and - 0.03, p = 0.03 (administrative). The comparator PPI was - 0.07, p = 0.4 (EMR) and - 0.11, p = 0.002 (administrative).

CONCLUSIONS

Using both EMR and administrative health data, we confirmed that the Diabetes Canada 2013 guideline dissemination strategy did not lead to an increased rate of coverage for vascular protective medications. Alternative strategies are needed to effect change in practice.

Impact of the Diabetes Canada Guideline Dissemination Strategy on the Prescription of Vascular Protective Medications: A Retrospective Cohort Study, 2010-2015

OBJECTIVE

The 2013 Diabetes Canada guidelines launched targeted dissemination tools and a simple assessment for vascular protection. We aimed to 1) examine changes associated with the launch of the 2013 guidelines and additional dissemination efforts in the rates of vascular protective medications prescribed in primary care for older patients with diabetes and 2) examine differences in the rates of prescriptions of vascular protective medications by patient and provider characteristics.

RESEARCH DESIGN AND METHODS

The study population included patients (≥40 years of age) from the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) with type 2 diabetes and at least one clinic visit from April 2010 to December 2015. An interrupted time series analysis was used to assess the proportion of eligible patients prescribed a statin, ACE inhibitor (ACEI)/angiotensin receptor blocker (ARB), or antiplatelet prescription in each quarter. Proton pump inhibitor (PPI) prescriptions were the reference control.

RESULTS

A dynamic cohort was used where participants were enrolled each quarter using a prespecified set of conditions (range 25,985-70,693 per quarter). There were no significant changes in statin (P = 0.43), ACEI/ARB (P = 0.42), antiplatelet (P = 0.39), or PPI (P = 0.16) prescriptions at baseline (guideline intervention). After guideline publication, there was a significant change in slope for statin (-0.52% per quarter, SE 0.15, P < 0.05), ACEI/ARB (-0.38% per quarter, SE 0.13, P < 0.05), and reference PPI (-0.18% per quarter, SE 0.05, P < 0.05) prescriptions.

CONCLUSIONS

There was a decrease in prescribing trends over time that was not specific to vascular protective medications. More effective knowledge translation strategies are needed to improve vascular protection in diabetes in order for patients to receive the most effective interventions.

Evaluation of Healthy User Effects With Metformin and Other Oral Antihyperglycemia Medication Users in Adult Patients With Type 2 Diabetes

OBJECTIVES

Healthy user bias, whereby health-seeking patients are more likely to initiate preventive therapies and engage in healthy lifestyle behaviours, is well known in observational studies, particularly with statins. However, its influence in studies of oral antihyperglycemic therapies is unknown. We sought to explore the healthy user effects in metformin users vs. nonusers on various health outcomes that should not be associated with metformin use.

METHODS

We conducted a retrospective cohort study using data from Alberta, between 2008 and 2015, to examine the association between metformin use and various health outcomes.

RESULTS

We identified 135,301 new users of oral antihyperglycemic agents. The mean age was 55 years, 75,949 (56%) were men and 130,725 (97%) had had at least 1 metformin prescription during a mean follow-up period of 3.4 years. Metformin users were less likely to be involved in accident-related events (adjusted hazard ratio [aHR] 0.90; 95% CI 0.85 to 0.96), were more likely to have preventive screening services (aHR 1.16; 95% CI 1.11 to 1.21), were less likely to experience other clinical events, such as asthma and gout attacks (aHR 0.90; 95% CI 0.84 to 0.97), and had lower risks for all-cause mortality (aHR 0.57; 95% CI 0.51 to 0.63) compared to nonusers.

CONCLUSIONS

Our results suggest that metformin users are more likely to initiate preventive therapies and engage in other healthy behaviours. Failure to account for these behaviours may introduce healthy user bias into studies evaluating the effects of oral antihyperglycemic therapies.

Surgery for Diabetes: Clinical and Mechanistic Aspects

According to the most recent publication by the Canadian Public Health Agency, obesity affects 25% of adults. In addition, there is a clear association between the recent rise in obesity and the increased prevalence of type 2 diabetes. Medical therapy for obesity has shown limited long-term effectiveness, and surgical treatment is now recognized by medical authorities as part of the armamentarium for the management of type 2 diabetes in severely obese patients. The current indications for obesity surgery and postoperative management are reviewed. The choice of surgery should balance expected benefits associated with weight loss (including remission rate of type 2 diabetes), side effects and the risks for early and long-term complications. Long-term outcomes of metabolic surgery for diabetes vary according to the type of surgery (ranging between 20% and 90% remission rates) and the underlying metabolic changes. Several controlled trials have been published in recent years confirming the superiority of metabolic surgery over medical treatment for the management of type 2 diabetes associated with severe obesity. Some of the known underlying mechanisms of action include a combination of caloric restriction, hormonal changes, decreased nutrient absorption and changes in bile acids, microbiota and incretins. Further research is needed to clarify the mechanistic changes associated with each surgical procedure and their respective long-term outcomes.

Is YouTube Useful as a Source of Health Information for Adults With Type 2 Diabetes? A South Asian Perspective

OBJECTIVES

To investigate the content, quality and popularity of information about type 2 diabetes available on YouTube.

METHODS

We searched YouTube with the terms Diabetes, Diabetes type 2, Diabetes South Asians, Diabetes Punjabi and Diabetes Hindi to identify videos concerning type 2 diabetes. A team of health-care providers independently classified the first 20 videos from each search as useful, misleading, or personal experience, rated them on a 5-point global quality scale (GQS) and categorized their content on a 26-point scale in duplicate. Useful videos were rated for reliability by using a 5-point modified DISCERN scale. Higher scores represent better quality, reliability and comprehensiveness.

RESULTS

Of 100 videos, 71 met the inclusion criteria; 45 (63.4%) were rated as useful (median GQS, 3; interquartile range [IQR], 2 to 4); and 23 (32.4%) were deemed misleading (median GQS, 1; IQR, 1 to 2). Median reliability and content scores for useful videos were 3 (IQR, 2 to 3) and 5 (IQR, 3 to 10), respectively, and 6 videos met ≥ 4 of 5 reliability criteria. Overall, misleading videos were more popular than useful videos (median, 233 views/day; IQR, 26 to 523; vs. 8.3 views/day; IQR, 0.4 to 134.6; p<0.01). Culturally tailored videos were just as likely to be misleading and had similar GQS scores in comparison to nonculturally tailored videos (32.1% vs. 32.6% and 3 vs. 3, respectively).

CONCLUSIONS

The quality of identified videos concerning type 2 diabetes was variable, and misleading videos were popular. Further creation and curation of high-quality video resources is required.

Thresholds and Targets for Hypertension Management in Adults With Type 2 Diabetes Should Remain at 130/80 mmHg: What's the Evidence?

Hypertension and diabetes are common comorbidities and are both modifiable risk factors for cardiovascular disease and death. Lowering blood pressure reduces target organ damage and prevents cardiovascular disease outcomes. The harmonized Canadian clinical practice guidelines for managing hypertension in people with diabetes provides health-behaviour advice and medical therapy recommendations for a threshold blood pressure of 130/80 mmHg and above and to target blood pressure to below 130/80 mmHg. We have reviewed the studies supporting these recommendations and others, and they appear to be at odds with the guidelines, including those for elderly people and patients with pre-existing cardiovascular disease.

Natural Health Products and Diabetes: A Practical Review

The prevalence of natural health product (NHP) use in Canada is extensive. Patients with chronic diseases, including diabetes, use NHPs at a higher rate than the general population. Many NHPs exert hypoglycemic effects, among other effects relevant to diabetes management. To provide a practical, clinical review of NHPs with such effects targeted to pharmacists, a literature search was performed to collect data on the efficacy and safety profiles of 10 commonly used NHPs that exert antidiabetic properties. The following NHPs are included in this clinical review: alpha-lipoic acid, chromium, magnesium, bitter melon, cinnamon, fenugreek, gymnema, milk thistle, Reishi mushroom and white mulberry. Given the potential of NHPs to additively cause hypoglycemia when used concurrently with conventional medications, pharmacists should be up to date with current evidence around NHPs that may affect diabetes care to prevent adverse reactions and interactions. In addition, effective and respectful communication with patients around NHP use and collaboration with various health-care providers are essential in the patient care process.

Use of Evidence-Based Therapy for Cardiovascular Risk Factors in Canadian Outpatients With Atrial Fibrillation: From the Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation (FREEDOM AF) and Co-ordinated National Network to Engage Physicians in the Care and Treatment of Patients With Atrial Fibrillation (CONNECT AF)

Using data collected from 2 national atrial fibrillation (AF) primary care physician chart audits (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation [FREEDOM AF] and Co-ordinated National Network to Engage Physicians in the Care and Treatment of Patients With Atrial Fibrillation [CONNECT AF]), we evaluated the frequency of, and factors associated with, the use of cardiovascular (CV) evidence-based therapies in Canadian AF outpatients with at least 1 CV risk factor or co-morbidity. Of the 11,264 patients enrolled, 9,495 (84.3%) were eligible for one or more CV evidence-based therapies. The proportions of patients with AF receiving all eligible guideline-recommended therapies were 40.8% of patients with coronary artery disease, 48.9% of patients with diabetes mellitus, 40.2% of patients with heart failure, 96.7% of patients with hypertension, and 55.1% of patients with peripheral arterial disease. Factors that were independently associated with nonreceipt of all indicated evidence-based therapies included sinus rhythm rather than AF at baseline and liver disease. In conclusion, although most Canadian outpatients with AF have CV risk factors or co-morbidities, a substantial portion of these patients did not receive all guideline-recommended therapies. These findings suggest that there is an opportunity to improve the quality of care for patients with AF in Canada.

Community Pharmacy-Based Inducement Programs Associated With Better Medication Adherence: A Cohort Study

BACKGROUND

Inducement programs can promote customer loyalty; however, the clinical effects of these programs are unknown.

OBJECTIVE

To examine relationships among inducement program use, medication adherence, and health outcomes.

METHODS

Alberta residents with ≥ 1 physician visit for diabetes or hypertension between April 2008 and March 2014 were eligible for this study and included if they were new statin users and alive at least 455 days after the first statin dispensation. Group assignment was based on whether all statin dispensations in the first year were obtained from pharmacies with or without inducement programs. Discontinuation was defined as no statin dispensations between 275 and 455 days after the first statin dispensation. Acute coronary syndrome (ACS) hospitalizations or deaths were identified between 456 days and 3 years after the first statin dispensation. Multivariable regression analyses were conducted to examine relationships among inducement program use, discontinuation, and ACS events.

RESULTS

Among the 159 998 new statin users, mean age was 60.2 (±13.7) years and 67 534 (42%) were women. Statin discontinuation occurred in 22 455 (28.9%) of 77 803 inducement group participants and 25 816 (31.4%) of 82 195 noninducement group participants (adjusted odds ratio = 0.88; 95% CI = 0.86-0.90). Risk of an ACS event was similar between groups (adjusted hazard ratio = 1.00; 95% CI 0.92-1.08); however, discontinuing statin therapy was associated with a higher risk of an ACS event (adjusted hazard ratio = 1.27; 95% CI = 1.16-1.39).

CONCLUSIONS

Inducement programs are associated with better adherence and not directly associated with risk of health outcomes.

Sex and gender considerations in Canadian clinical practice guidelines: a systematic review

BACKGROUND

The importance of sex and gender in the diagnosis and management of health conditions is well established, but the extent to which this evidence is integrated into clinical practice guidelines remains unknown. We aimed to determine the proportion of Canadian clinical practice guidelines that integrate evidence on sex and gender considerations.

METHODS

We searched the Canadian Medical Association's CPG Infobase, PubMed, all provincial/territorial websites and websites of professional organizations for English- and French-language Canadian clinical practice guidelines published between January 2013 and June 2015 on selected conditions identified as priorities by policy-makers and practitioners. Citations and text were searched electronically using keyword terms related to sex and gender. Three investigators independently analyzed and categorized the content of text-positive clinical practice guidelines based on clinical relevance for practitioners.

RESULTS

Of the 118 clinical practice guidelines that met the inclusion criteria, 79 (66.9%) were text-positive for sex and/or gender keywords; 8 (10%) of the 79 used the keywords only in relation to pregnancy. Of the remaining 71 guidelines, 25 (35%) contained sex-related diagnostic or management recommendations. An additional 5 (7%) contained recommendations for sex-specific laboratory reference values, 29 (41%) referred to differences in epidemiologic features or risk factors only, and 12 (17%) contained nonrelevant mentions of search keywords. Twenty-five (35%) of the text-positive guidelines used the terms "sex" and/or "gender" correctly.

INTERPRETATION

Recommendations related to sex and gender are inconsistently reported in Canadian clinical practice guidelines. Guidelines such as the Sex and Gender Equity in Research guidelines may help inform the meaningful inclusion of sex and gender evidence in the development of clinical practice guidelines.

Lipid Management in Diabetes with a Focus on Emerging Therapies

We reviewed the current and potential future management of dyslipidemia in patients with diabetes, with a focus on reduction of risk for macrovascular disease. We considered novel dyslipidemia therapies, in particular, inhibitors of proprotein convertase subtilisin kexin 9 (PCSK9), which have been approved in Canada for reducing low-density lipoprotein (LDL) cholesterol in certain patient groups. We searched for English-language randomized clinical trials (RCTs) of lipid-lowering modalities, mainly since 2012, that included patients with diabetes. The results from some RCTs may have future impacts on the approach to patients with diabetes. In particular, ezetimibe added to statins in the context of acute coronary syndromes seems to have particular benefits in patients with diabetes. Also, patients with diabetes show no differences, so far, from patients without diabetes with respect to efficacy of PCSK9 inhibitors in LDL cholesterol reduction and also in the frequency of adverse effects. RCTs of clinical outcomes with PCSK9 inhibitors performed exclusively in patients with diabetes are desirable, but approval of these agents for use in Canada has occurred before the availability of such results. Clinicians will have to gauge whether certain subjects with diabetes might benefit from this therapy, such as those with superimposed familial dyslipidemia, those with recurrent cardiovascular events and recalcitrant LDL cholesterol levels despite maximally tolerated statin therapy and those with high cardiovascular risk who cannot tolerate any dose of statins.

Community pharmacy-based A1c screening: a Canadian model for diabetes care

Objectives

Point-of-care HbA1c screening devices are a valuable tool that community pharmacists can use to monitor patients with diabetes and improve their overall management. We previously reported our experiences using these devices to assess glycaemic control in diabetic patients at three community pharmacy locations in Toronto, Ontario. Here, we report data from screening of over 1000 patients at clinics held across Canada.

Methods

Community pharmacies across Canada offering A1c screening as part of their professional programmes were invited to upload screening data to a central database. A1c analysis was performed using the Bayer A1c Now. Patient recruitment and approach to A1c screening were at the discretion of the participating pharmacies and were not standardized. Data collection took place over a period of 8 months.

Key findings

The majority of patients screened (59.1%) had A1c values above target, indicating inadequate glycaemic control. Glycaemic control was generally poorer among patients on more intensive treatment regimens. A total of 1711 clinical interventions were performed by pharmacists. An average of two interventions were performed per patient, and we observed a trend towards increased numbers of interventions in patients with poorer glycaemic control. The prevalence of specific types of interventions showed an apparent shift from predominantly pharmacist-directed interventions in patients with better glycaemic control towards an increased prevalence of physician-directed interventions in patients with poorer glycaemic control.

Conclusions

These results illustrate the prevalence of suboptimal glycaemic control among diabetic patients in the community, which represents a significant opportunity for pharmacists to use point-of-care screening to detect hyperglycaemia and intervene to improve disease management when warranted.

Connexin-Based Therapeutics and Tissue Engineering Approaches to the Amelioration of Chronic Pancreatitis and Type I Diabetes: Construction and Characterization of a Novel Prevascularized Bioartificial Pancreas

Total pancreatectomy and islet autotransplantation is a cutting-edge technique to treat chronic pancreatitis and postoperative diabetes. A major obstacle has been low islet cell survival due largely to the innate inflammatory response. Connexin43 (Cx43) channels play a key role in early inflammation and have proven to be viable therapeutic targets. Even if cell death due to early inflammation is avoided, insufficient vascularization is a primary obstacle to maintaining the viability of implanted cells. We have invented technologies targeting the inflammatory response and poor vascularization: a Cx43 mimetic peptide that inhibits inflammation and a novel prevascularized tissue engineered construct. We combined these technologies with isolated islets to create a prevascularized bioartificial pancreas that is resistant to the innate inflammatory response. Immunoconfocal microscopy showed that constructs containing islets express insulin and possess a vascular network similar to constructs without islets. Glucose stimulated islet-containing constructs displayed reduced insulin secretion compared to islets alone. However, labeling for insulin post-glucose stimulation revealed that the constructs expressed abundant levels of insulin. This discrepancy was found to be due to the expression of insulin degrading enzyme. These results suggest that the prevascularized bioartificial pancreas is potentially a tool for improving long-term islet cell survival in vivo.

Prevalence of high on-treatment platelet reactivity in diabetic patients treated with aspirin

BACKGROUND

Randomized controlled trials have shown that ≤ 100 mg aspirin daily is not effective for primary prevention of cardiovascular events in diabetes; however, clinical and pharmacologic evidence suggests these patients need >100 mg for adequate antiplatelet activity. Although high on-treatment platelet reactivity (HTPR) could explain the lack of benefit, prevalence of HTPR in diabetes is not known. This systematic review examined the relationship between daily aspirin dose and prevalence of HTPR in patients with diabetes.

METHODS

Three electronic databases were searched until May 2013 using database-appropriate terms for aspirin, resistance, and diabetes. Studies were included if prevalence of HTPR was reported according to daily dose and diabetes status. Patients were stratified by daily aspirin dose and the weighted mean prevalence across studies was calculated. Where appropriate, pooled relative risks (RR) were calculated using a random-effects model.

RESULTS

Data were available from 31 studies that enrolled 2147 diabetic patients. Overall, prevalence of HTPR was 21.9% (95% confidence interval [CI], 15.2%-28.5%) in diabetic patients and 15.8% (95% CI, 11.4%-20.3%) in nondiabetic patients (pooled RR 1.36; 95% CI, 1.08-1.71; I(2) 56%). Prevalence appeared to be dose related, with 398 (23.6%) of 1689 diabetic patients using ≤ 100 mg daily having HTPR compared with 64 (12.3%) of 518 diabetic patients using 101-325 mg daily (pooled RR 1.70; 95% CI, 1.07-2.72; I(2) 0%).

CONCLUSIONS

Although these observations should be verified in a clinical trial, the possibility that 1 in 4 patients have HTPR with doses commonly used in diabetes could have significant implications on overall effectiveness of aspirin.