Metformin and Cancer: Solutions to a Real-World Evidence Failure

The quest to repurpose metformin, an antidiabetes drug, as an agent for cancer prevention and treatment, which began in 2005 with an observational study that reported a reduction in cancer incidence among metformin users, generated extensive experimental, observational, and clinical research. Experimental studies revealed that metformin has anticancer effects via various pathways, potentially inhibiting cancer cell proliferation. Concurrently, multiple nonrandomized observational studies reported remarkable reductions in cancer incidence and outcomes with metformin use. However, these studies were shown, in 2012, to be affected by time-related biases, such as immortal time bias, which tend to greatly exaggerate the benefit of a drug. The observational studies that avoided these biases did not find an association. Subsequently, the randomized trials of metformin for the treatment of type 2 diabetes and as adjuvant therapy for the treatment of various cancers, advanced or metastatic, did not find reductions in cancer incidence or outcomes. Most recently, the largest phase 3 randomized trial of metformin as adjuvant therapy for breast cancer, which enrolled 3,649 women with a 5-year follow-up, found no benefit for disease-free survival or overall survival with metformin. This major failure of observational real-world evidence studies in correctly assessing the effects of metformin on cancer incidence and outcomes was caused by preventable biases which, surprisingly, are still prominent in 2022. Rigorous approaches for observational studies that emulate randomized trials, such as the incident and prevalent new-user designs along with propensity scores, avoid these biases and can provide more accurate real-world evidence for the repurposing of drugs such as metformin.

Occupation as a gendered-role and outcome in systemic sclerosis

Objective:

Sex and gender are of growing scientific interest in disease onset and course. While sex differences have been shown to exist in systemic sclerosis, there is a paucity of data on gender. Our objective was to examine the association between occupation, a gender-related role and outcomes in systemic sclerosis.

Methods:

An occupation score ranging from 0 to 100, with lower scores representing occupations traditionally held by men and higher scores traditionally held by women, was constructed using the National Occupational Classification 2016 and data from Statistics Canada. Subjects in the Canadian Scleroderma Research Group registry were assigned an occupation score based on self-reported occupation. Multivariate models, adjusted for sex, age, smoking and education were used to estimate the independent effect of occupation score on systemic sclerosis outcomes.

Results:

We included 1104 subjects, of which 961 were females (87%) and 143 (13%) males. There were differences between females versus males: disease duration (9.9 vs 7.6 years, p = 0.002), diffuse disease (35% vs 54%, p < 0.001), interstitial lung disease (28% vs 37%, p = 0.021) and pulmonary hypertension (10% vs 4%, p = 0.033), but not pain, response to treatment and mortality. The median occupation scores differed between females and males (84.3 (interquartile range 56.8, 89.4) vs 24.9 (4.3, 54.1), p < 0.001). The Spearman correlation between sex and occupation score was 0.44, indicating a weak correlation. In adjusted analyses, occupation score was not an independent predictor of disease subset (diffuse vs limited), interstitial lung disease, pulmonary hypertension, pain, response to treatment or mortality.

Conclusion:

We did not find independent associations between an occupation score, a gender-related role and outcomes in systemic sclerosis. These results should be interpreted with caution as occupation may be a poor measure of gender. Future research using a validated measure of gender will be needed to generate robust data on the effect of gender in systemic sclerosis.

Selective serotonin reuptake inhibitors and the risk of type 2 diabetes mellitus in youths

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) have been associated with type 2 diabetes mellitus (T2DM) in youths, possibly via 5-HT_2C, H₁ receptors and serotonin transporter (SERT). SSRIs have similar affinity for SERT but variable affinity for 5-HT_2C and H₁. This study assessed whether SSRIs with strong affinity for 5-HT_2C and H₁ (relative to SERT) were associated with T2DM risk compared with weak-affinity SSRIs.

METHODS

Using the UK Clinical Practice Research Datalink, we assembled a cohort of patients aged 5-24, newly prescribed a strong-affinity SSRI (citalopram, escitalopram, fluoxetine) or weak affinity (paroxetine, sertraline, fluvoxamine) between 1990 and 2019. We controlled for confounding using standardized mortality ratio weighting, estimated from calendar time-specific propensity scores. We used weighted Cox proportional hazards models to estimate hazard ratios (HRs) of incident T2DM with 95 % confidence intervals (CIs).

RESULTS

The cohort included 347,368 new users of strong-affinity SSRIs and 131,359 of weak-affinity SSRIs. Strong-affinity SSRIs were not associated with an increased T2DM risk compared with weak-affinity SSRIs (incidence rate 2.8 vs 2.7 per 1000 person-years; HR 1.03, 95 % CI 0.85-1.25). T2DM risk did not vary with duration of use, age or sex. However, the HR was numerically higher in youths with normal or low weight (HR 1.30, 95 % CI 0.85-1.98) and with prior antipsychotic use (HR 1.62, 95 % CI 0.83-3.18).

LIMITATIONS

Median duration of SSRI use, in line with real-world SSRI prescribing, was relatively short.

CONCLUSION

T2DM risk did not differ between strong- and weak-affinity SSRIs, providing reassurance for clinicians when choosing between SSRIs in youths.

The association of long-acting insulin analogue use versus neutral protamine Hagedorn insulin use and the risk of major adverse cardiovascular events among individuals with type 2 diabetes: A population-based cohort study

AIMS

To compare the risk of cardiovascular outcomes associated with long-acting insulin analogues versus neutral protamine Hagedorn (NPH) insulin among patients with type 2 diabetes.

MATERIALS AND METHODS

We conducted a population-based retrospective cohort study using the UK Clinical Practice Research Datalink Aurum, linked with hospitalization and vital statistics data. Patients with type 2 diabetes who initiated basal insulin treatment between 2002 and 2018 were included in the study. Exposure was defined as current use of long-acting insulin analogues or NPH insulin, defined using a time-varying approach. The primary outcome was major adverse cardiovascular events (MACE; a composite endpoint of myocardial infarction, ischaemic stroke and cardiovascular death). We used a marginal structural Cox proportional hazards model to estimate the hazard ratio (HR) and 95% confidence interval (CI) for MACE with current use of long-acting insulin analogues versus NPH insulin, and in secondary analyses, by long-acting insulin molecule.

RESULTS

Our cohort included 57 334 patients. A total of 3494 MACE occurred over a mean follow-up of 1.6 years (incidence rate 37.4, 95% CI 36.2 to 38.7 per 1000 person-years). Long-acting insulin analogues were associated with a decreased risk of MACE compared to NPH insulin (HR 0.89, 95% CI 0.83 to 0.96).

CONCLUSIONS

Current use of long-acting insulin analogues is associated with a modestly reduced risk of MACE compared to current use of NPH insulin among patients with type 2 diabetes. This study could have important implications for drug plan managers and guideline-writing committees for recommendations of insulin treatment for type 2 diabetes.

Long-term clinical outcomes of oral antidiabetic drugs as fixed-dose combinations: A nationwide retrospective cohort study

AIM

To compare treatment patterns and clinical outcomes of single-pill fixed-dose combination (FDC) and two-pill combination (TPC) therapies using real-world data.

METHODS

We conducted a nationwide retrospective cohort study using South Korea's healthcare database (2002-2015). We identified two cohorts of incident patients with type 2 diabetes who initiated FDC or TPC therapy within 4 months of their first prescription for metformin or sulphonylurea. We examined persistence and adherence patterns and the clinical outcome of a composite endpoint of death or hospitalization for acute myocardial infarction, heart failure or stroke and compared the differences in treatment patterns and clinical outcomes using Cox models.

RESULTS

Of 5143 and 10 973 patients who initiated FDC and TPC therapy, respectively, we identified 5143 patient pairs after propensity score matching. The FDC group exhibited greater median time to treatment discontinuation (163 vs. 146 days), and proportion of days covered at 12 months (mean 0.60 vs. 0.57, P < .0001) and at 24 months (0.53 vs. 0.51, P = .014) than the TPC group. The FDC group, compared with the TPC group, had reduced risks of the composite clinical outcome (hazard ratio 0.86, 95% confidence intervals 0.77-0.97) and hospitalization for stroke (0.80, 0.67-0.96).

CONCLUSION

FDC therapy may provide favourable cardiovascular benefits, especially reducing the risk of hospitalization for stroke, and has better medication adherence among patients with type 2 diabetes.

Atorvastatin lowers serum calcium levels in lithium-users: results from a randomized controlled trial

BACKGROUND

Although lithium is considered the gold-standard treatment for bipolar disorder (BD), it is associated with a variety of major endocrine and metabolic side effects, including parathyroid hormone (PTH) dependent hypercalcemia. Aside from surgery and medication discontinuation, there are limited treatments for hypercalcemia. This paper will assess data from a randomized controlled trial (RCT).

METHODS

This is a secondary analysis of an RCT that explored the effects of atorvastatin (n = 27) versus placebo (n = 33) on lithium-induced nephrogenic diabetes insipidus (NDI) in patients with BD and major depressive disorder (MDD) using lithium (n = 60), over a 12-week period. This secondary analysis will explore serum calcium levels and thyroid stimulating hormone (TSH) measured at baseline, week 4, and week 12.

RESULTS

At 12-weeks follow-up while adjusting results for baseline, linear regression analyses found that corrected serum calcium levels were significantly lower in the treatment group (mean (M) = 2.30 mmol/L, standard deviation (SD) = 0.07) compared to the placebo group (M = 2.33 mmol/L, SD = 0.07) (β = - 0.03 (95% C.I.; - 0.0662, - 0.0035), p = 0.03) for lithium users. There were no significant changes in TSH.

CONCLUSION

In lithium users with relatively normal calcium levels, receiving atorvastatin was associated with a decrease in serum calcium levels. Although exciting, this is a preliminary finding that needs further investigation with hypercalcemic patients. Future RCTs could examine whether atorvastatin can treat PTH dependent hypercalcemia due to lithium and other causes.

Effectiveness and safety of apixaban vs. rivaroxaban in patients with atrial fibrillation and type 2 diabetes mellitus

AIMS

To evaluate the effectiveness and safety of apixaban vs. rivaroxaban among patients with non-valvular atrial fibrillation (NVAF) and type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

Using the United Kingdom's Clinical Practice Research Datalink linked to the Hospital Episode Statistics repository, and the Office for National Statistics database, we identified a cohort of patients with NVAF and T2DM newly treated with apixaban or rivaroxaban between 2013 and 2020. Propensity scores with standardised mortality ratio weighting were used to control for confounding. We used weighted Cox proportional hazards models to estimate separately the hazard ratios (HRs) with 95% confidence intervals (CIs) of ischemic stroke, major bleeding, and major adverse limb events associated with use of apixaban compared with rivaroxaban. We also evaluated whether the risk was modified by age, sex, duration of diabetes, microvascular and macrovascular complications of diabetes, nephropathy, CHA2DS2-VASc and HAS-BLED scores, and by dose (standard vs low dose).

RESULTS

The cohort included 11,561 apixaban and 8,265 rivaroxaban users. Apixaban was associated with a similar risk of stroke (HR 0.99, 95% CI 0.79-1.23), and a 32% reduced risk of major bleeding (HR 0.68, 95% CI 0.59-0.78), compared with rivaroxaban. The risk of major adverse limb events was similar between apixaban and rivaroxaban (HR 0.75, 95% CI 0.54-1.04). Overall, the risk of ischemic stroke and major bleeding was consistent in stratified analyses.

CONCLUSIONS

Among patients with NVAF and T2DM, apixaban was associated with a similar risk of stroke, and a lower risk of major bleeding compared with rivaroxaban.

The association between glycaemic control during hospitalization and risk of adverse events: A retrospective cohort study

Introduction

Hyperglycaemia is common during hospitalization; glycaemic targets in non‐critical care settings have not been well studied. We assessed associations between inpatient glycaemic control and adverse events.

Methods

We conducted a retrospective cohort study on non‐critically ill medical patients hospitalized in a tertiary care hospital between 2015 and 2018. Mean glycaemia during the first four days of hospitalization was categorized as 4.0–7.0 mmol/L, 7.1–10.0 mmol/L and >10.0 mmol/L. The primary outcome was a composite of adverse events including mortality, infections, acute kidney injury, thromboembolic and cardiovascular events. The secondary outcome was hypoglycaemia, defined as any glycaemia <4.0 mmol/L. Logistic regression was used to assess adverse events, and a Cox proportional hazards model was used to estimate hypoglycaemia risk.

Results

Our cohort included 1,368 patients, of whom 407 (29.8%) experienced an adverse event. We did not find associations between glycaemia of 4.0–7.0 mmol/L (adjusted odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.63–1.23) or glycaemia of >10.0 mmol/L (adjusted OR: 0.98, 95% CI: 0.75–1.28) and the occurrence of adverse events, compared to a glycaemia of 7.1–10.0 mmol/L. Glycaemia of >10.0 mmol/L was associated with an increased risk of hypoglycaemia (adjusted hazard ratio [HR]: 1.72, 95% CI: 1.21–2.45). Hypoglycaemia was associated with adverse events (adjusted OR 1.85, 95% CI 1.31–2.60).

Conclusions

Neither glycaemia of 4.0–7.0 mmol/L nor glycaemia of >10.0mmol/L during non‐critical care hospitalization was associated with increased adverse events. Glycaemia of >10.0 mmol/L was associated with increased hypoglycaemia, likely due to aggressive glucose lowering. These findings highlight the need for further studies to discern optimal inpatient glycaemic targets.

Levothyroxine and the risk of adverse pregnancy outcomes in women with subclinical hypothyroidism: a systematic review and meta-analysis

BACKGROUND

Levothyroxine replacement therapy may decrease the risk of adverse pregnancy outcomes among women with subclinical hypothyroidism (SCH). The aim of this study is to conduct a systematic review and meta-analysis to examine the risk of adverse pregnancy, perinatal, and early childhood outcomes among women with SCH treated with levothyroxine.

METHODS

A systematic literature search was conducted using Ovid-Medline, Ovid-EMBASE, Pubmed (non-Medline), Ebsco-CINAHL Plus with full text and Cochrane Library databases. Randomized controlled studies (RCTs) and observational studies examining the association between treatment of SCH during pregnancy and our outcomes of interest were included. Studies that compared levothyroxine treatment versus no treatment were eligible for inclusion. Data from included studies were extracted and quality assessment was performed by two independent reviewers.

RESULTS

Seven RCTs and six observational studies met our inclusion criteria. A total of 7342 individuals were included in these studies. RCTs demonstrated several sources of bias, with lack of blinding of the participants or research personnel; only one study was fully blinded. In the observational studies, there was moderate to serious risk of bias due to lack of adjustment for certain confounding variables, participant selection, and selective reporting of results. Pooled analyses showed decreased risk of pregnancy loss (RR: 0.79; 95% CI: 0.67 to 0.93) and neonatal death (RR: 0.35; 95% CI: 0.17 to 0.72) associated with levothyroxine treatment during pregnancy among women with SCH. There were no associations between levothyroxine treatment and outcomes during labour and delivery, or cognitive status in children at 3 or 5 years of age.

CONCLUSION

Treatment of SCH with levothyroxine during pregnancy is associated with decreased risks of pregnancy loss and neonatal death. Given the paucity of available data and heterogeneity of included studies, additional studies are needed to address the benefits of levothyroxine use among pregnant women with SCH.

SGLT-2 inhibitors and the risk of hospitalization for community-acquired pneumonia: A population-based cohort study

PURPOSE

Sodium-glucose co-transporter 2 inhibitors (SGLT-2i) have been associated with an increased risk of genitourinary tract infections. Through similar biological mechanisms, they may also increase the risk of community-acquired pneumonia. Our objective was to compare the rate of hospitalization for community-acquired pneumonia (HCAP) with SGLT-2i compared to dipeptidyl peptidase-4 inhibitors (DPP-4i) among patients with type 2 diabetes.

METHODS

We used the United Kingdom's Clinical Practice Research Datalink Gold, linked to hospitalization data, to construct a cohort of patients with type 2 diabetes. Using a time-dependent Cox proportional hazards model, we estimated the adjusted hazard ratio (HR) for HCAP with current use of SGLT-2i versus DPP-4i.

RESULTS

Among 29 896 patients, 705 HCAPs occurred over a mean follow-up of 1.7 years (SD: 1.2). Incidence rates for SGLT-2i and DPP-4i users were 6.2 (95% confidence interval [CI]: 3.7, 10.2) and 17.8 (95% CI: 15.3, 20.7) per 1000 person-years, respectively. Current use of SGLT-2i was associated with a decreased risk of HCAP compared to current use of DPP-4i (adjusted HR: 0.48, 95% CI: 0.28, 0.82). However, a comparison of SGLT-2i versus glucagon-like peptide-1 receptor agonists (GLP-1 RA) found no difference in risk of HCAP (adjusted HR: 0.94, 95% CI: 0.44, 1.89).

CONCLUSIONS

SGLT-2i are associated with a decreased rate of HCAP compared to DPP-4i, but not when compared to GLP-1 RA, among patients with type 2 diabetes.

Type 2 diabetes mellitus and risk of community-acquired pneumonia: a systematic review and meta-analysis of observational studies

BACKGROUND

People with type 2 diabetes are at greater risk for infections than those without type 2 diabetes. Our objective was to examine the association between type 2 diabetes and the risk of community-acquired pneumonia (CAP).

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, CINAHL, ProQuest theses and dissertations, Global Health, the Global Index Medicus of the World Health Organization, and Google Scholar. We included observational studies published in English or French between Jan. 1, 1946 (start of MEDLINE) and July 18, 2020. Two independent reviewers extracted data and assessed quality using the ROBINS-I tool. DerSimonian-Laird random-effects models were used to pool estimates of the association between type 2 diabetes and CAP.

RESULTS

Our systematic review included 15 articles, reporting on 13 cohort studies and 4 case-control studies (14 538 968 patients). All studies reported an increased risk of pneumonia among patients with type 2 diabetes, and all were at serious risk of bias. When estimates were pooled across studies, the pooled relative risk was 1.64 (95% confidence interval [CI] 1.55-1.73); although there was a substantial amount of relative heterogeneity (I 2 94.2), the amount of absolute heterogeneity was more modest (T2 0.008). The relative risk was 1.70 (95% CI 1.63-1.77, I 2 85.2%, T2 0.002) among cohort studies (n = 13), and the odds ratio was 1.54 (95% CI 1.14-2.09, I 2 92.7%, T2 0.07) among case-control studies (n = 4).

INTERPRETATION

Type 2 diabetes may be associated with an increased risk of CAP; however, the available evidence is from studies at serious risk of bias, and additional, high-quality studies are needed to confirm these findings.

PROSPERO REGISTRATION

CRD42018116409.

Sodium-Glucose Cotransporter 2 Inhibitors and the Risk of Below-Knee Amputation: A Multicenter Observational Study

OBJECTIVE

Reports of amputations associated with sodium-glucose cotransporter 2 (SGLT2) inhibitors have been inconsistent. We aimed to compare the risk of below-knee amputation with SGLT2 inhibitors versus dipeptidyl peptidase 4 (DPP-4) inhibitors among patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

This multicenter observational study used administrative health care databases from seven Canadian provinces and the U.K. Incident SGLT2 inhibitor users were matched to DPP-4 inhibitor users using a prevalent new-user design and time-conditional propensity scores. Cox proportional hazards models were used to estimate site-specific adjusted hazard ratios (HR) and corresponding 95% CIs of incident below-knee amputation for SGLT2 inhibitor versus DPP-4 inhibitor users. Random effects meta-analyses were used to pool the site-specific results.

RESULTS

The study cohort included 207,817 incident SGLT2 inhibitor users matched to 207,817 DPP-4 inhibitor users. During a mean exposed follow-up time of 11 months, the amputation rate was 1.3 per 1,000 person-years among SGLT2 inhibitor users and 1.5 per 1,000 person-years among DPP-4 inhibitor users. The adjusted HR of below-knee amputations associated with SGLT2 inhibitor use compared with DPP-4 inhibitor use was 0.88 (95% CI 0.71-1.09). Similar results were obtained in stratified analyses by specific SGLT2 inhibitor molecule.

CONCLUSIONS

In this large multicenter observational study, there was no association between SGLT2 inhibitor use and incident below-knee amputations among patients with type 2 diabetes compared with DPP-4 inhibitor use. While these findings provide some reassurance, studies with a longer duration of follow-up are needed to assess potential long-term effects.

Subclinical hypothyroidism and the risk of cancer incidence and cancer mortality: a systematic review

BACKGROUND

Thyroid hormone has been shown to be involved in carcinogenesis via its effects on cell proliferation pathways. The objective of this study is to determine the association between subclinical hypothyroidism (SCH) and the risk of incident cancer and cancer mortality via systematic review.

METHODS

A systematic search was performed on Medline and Pubmed to identify relevant studies. Randomized controlled trials, and observational studies assessing SCH or its treatment and the risk of incident cancer or cancer mortality were identified.

RESULTS

A total of 7 cohort and 2 case-control studies met our inclusion criteria. In general, these studies were of medium to good quality. Overall, studies revealed no association between SCH and breast and prostate cancer. One study found that untreated SCH may be associated with an increased risk of colorectal cancer (adjusted odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.08-1.24). One study showed an increased risk in thyroid cancer incidence (adjusted OR: 3.38; 95% CI: 2.05-5.59) associated with elevation of a thyroid stimulating hormone (TSH) of > 1.64mIU/L. Two studies found an increase in cancer mortality among patients with SCH compared to euthyroid individuals; in contrast one study found no association between subclinical hypothyroidism and cancer mortality among aging men.

CONCLUSION

The number of studies examining thyroid dysfunction and cancer risk and mortality is limited. Future studies assessing the association between thyroid dysfunction and cancer risk and mortality are needed, which will further address the need to treat subclinical hypothyroidism.

Incretin-based drugs and risk of lung cancer among individuals with type 2 diabetes

AIM

To assess whether dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists are associated with an increased lung cancer risk among individuals with type 2 diabetes.

METHODS

We conducted a population-based cohort study using the UK Clinical Practice Research Datalink. We identified 130 340 individuals newly treated with antidiabetes drugs between January 2007 and March 2017, with follow-up until March 2018. We used a time-varying approach to model use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists compared with use of other second- or third-line antidiabetes drugs. We used Cox proportional hazards models to estimate the adjusted hazard ratios, with 95% CIs, of incident lung cancer associated with use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists, separately, by cumulative duration of use, and by time since initiation.

RESULTS

A total of 790 individuals were newly diagnosed with lung cancer (median follow-up 4.6 years, incidence rate 1.5/1000 person-years, 95% CI 1.4-1.6). Compared with use of second-/third-line drugs, use of dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists was not associated with an increased lung cancer risk (hazard ratio 1.07, 95% CI 0.87-1.32, and hazard ratio 1.02, 95% CI 0.68-1.54, respectively). There was no evidence of duration-response relationships.

CONCLUSIONS

In individuals with type 2 diabetes, use of incretin-based drugs was not associated with increased lung cancer risk.

Comparative cardiovascular and hypoglycaemic safety of glimepiride in type 2 diabetes: A population-based cohort study

AIM

To assess the incidence of cardiovascular and hypoglycaemic adverse events associated with glimepiride compared with other second-generation sulphonylureas among patients with type 2 diabetes in a real-world clinical setting.

MATERIALS AND METHODS

We identified all sulphonylurea initiators between 1998 and 2017 in the UK Clinical Practice Research Datalink. Using a prevalent new-user design, glimepiride initiators were matched 1:4 with initiators of other second-generation sulphonylureas on calendar time, prior sulphonylurea use, and time-conditional high-dimensional propensity score. Cox proportional hazards models yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for myocardial infarction, ischaemic stroke, severe hypoglycaemia, cardiovascular death, and all-cause mortality.

RESULTS

Among 66 032 sulphonylurea new users, 6438 initiated glimepiride and were matched to up to 20 582 initiators of other second-generation sulphonylureas. During a mean follow-up of 1.3 years, glimepiride was associated with a similar incidence of myocardial infarction (HR 0.99, 95% CI 0.75-1.30) and ischaemic stroke (HR 0.96, 95% CI 0.72-1.27) compared with other second-generation sulphonylureas, while there was a non-significant trend towards a higher incidence of severe hypoglycaemia (HR 1.24, 95% CI 0.92-1.68). Glimepiride was also associated with a lower incidence of all-cause mortality (HR 0.77, 95% CI 0.67-0.89), and a non-significant but similar trend for cardiovascular death (HR 0.83, 95% CI 0.65-1.05).

CONCLUSIONS

Glimepiride was associated with a lower incidence of all-cause mortality compared with other second-generation sulphonylureas.

Cardiovascular and Cerebrovascular Safety of Testosterone Replacement Therapy Among Aging Men with Low Testosterone Levels: A Cohort Study

PURPOSE

We assessed the risk of ischemic stroke, transient ischemic attack, and myocardial infarction associated with testosterone replacement therapy (TRT) among aging men with low testosterone levels.

METHODS

Using the UK Clinical Practice Research Datalink, we formed a cohort of men aged 45 years or older with low testosterone levels and no evidence of hypogonadotropic or testicular disease, between 1995 and 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) of a composite of ischemic stroke/transient ischemic attack and myocardial infarction were estimated using time-dependent Cox proportional hazards models, comparing current use of TRT with nonuse.

RESULTS

The cohort included 15,401 men. During 71,541 person-years of follow-up, 850 patients experienced an ischemic stroke/transient ischemic attack/myocardial infarction (crude incidence rate 1.19 [95% confidence interval (CI), 1.11-1.27] per 100 persons per year). Compared with nonuse, current use of TRT was associated with an increased risk of the composite outcome (HR 1.21; 95% CI, 1.00-1.46). This risk was highest in the first 6 months to 2 years of continuous TRT use (HR 1.35; 95% CI, 1.01-1.79), as well as among men aged 45-59 years (HR 1.44; 95% CI, 1.07-1.92).

CONCLUSIONS

TRT may increase the risk of cardiovascular events in aging men with low testosterone levels, particularly in the first 2 years of use. In the absence of identifiable causes of hypogonadism, TRT should be initiated with caution among aging men with low testosterone levels.

Dipeptidyl Peptidase 4 Inhibitors and the Risk of Bullous Pemphigoid Among Patients With Type 2 Diabetes

OBJECTIVE

There are uncertainties regarding the association between dipeptidyl peptidase 4 (DPP-4) inhibitors and bullous pemphigoid (BP), a potentially severe autoimmune skin disease. Thus, we conducted a population-based study to determine whether use of DPP-4 inhibitors, when compared with other second- to third-line antidiabetic drugs, is associated with an increased risk of BP in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Using the U.K. Clinical Practice Research Datalink, we conducted a cohort study among 168,774 patients initiating antidiabetic drugs between January 2007 and March 2018. Using time-dependent Cox proportional hazards models, we estimated adjusted hazard ratios (HRs) with 95% CIs of incident BP associated with current use of DPP-4 inhibitors, compared with current use of other second- to third-line antidiabetic drugs. We also conducted a propensity score-matched analysis to assess the impact of residual confounding.

RESULTS

During 711,311 person-years of follow-up, 150 patients were newly diagnosed with BP (crude incidence rate, 21.1 per 100,000 person-years). Current use of DPP-4 inhibitors was associated with an increased risk of BP (47.3 vs. 20.0 per 100,000 person-years; HR 2.21 [95% CI 1.45-3.38]). HRs gradually increased with longer durations of use, reaching a peak after 20 months (HR 3.60 [95% CI 2.11-6.16]). Similar results were obtained in the propensity score-matched analysis (HR 2.40 [95% CI 1.13-4.66]).

CONCLUSIONS

In this large population-based study, use of DPP-4 inhibitors was associated with an at least doubling of the risk of BP in patients with type 2 diabetes, albeit the absolute risk was low.

Sulfonylureas as second line drugs in type 2 diabetes and the risk of cardiovascular and hypoglycaemic events: population based cohort study

OBJECTIVE

To assess whether adding or switching to sulfonylureas is associated with an increased risk of myocardial infarction, ischaemic stroke, cardiovascular death, all cause mortality, and severe hypoglycaemia, compared with remaining on metformin monotherapy in patients with type 2 diabetes.

DESIGN

Population based cohort study.

SETTING

General practices contributing data to the UK Clinical Practice Research Datalink.

PARTICIPANTS

Patients with type 2 diabetes initiating metformin monotherapy between 1998 and 2013.

MAIN OUTCOME MEASURES

Using the prevalent new-user cohort design we matched 1:1 patients adding or switching to sulfonylureas with those remaining on metformin monotherapy on high-dimensional propensity score, haemoglobin A1c, and number of previous metformin prescriptions. The two groups were compared using Cox proportional hazards models to estimate adjusted hazard ratios and 95% confidence intervals for the study outcomes.

RESULTS

Among 77 138 metformin initiators, 25 699 added or switched to sulfonylureas during the study period. During a mean follow-up of 1.1 years, sulfonylureas were associated with an increased risk of myocardial infarction (incidence rate 7.8 v 6.2 per 1000 person years, hazard ratio 1.26, 95% confidence interval 1.01 to 1.56), all cause mortality (27.3 v 21.5, 1.28, 1.15 to 1.44), and severe hypoglycaemia (5.5 v 0.7, 7.60, 4.64 to 12.44) compared with continuing metformin monotherapy. There was a trend towards increased risks of ischaemic stroke (6.7 v 5.5, 1.24, 0.99 to 1.56) and cardiovascular death (9.4 v 8.1, 1.18, 0.98 to 1.43). Compared with adding sulfonylureas, switching to sulfonylureas was associated with an increased risk of myocardial infarction (hazard ratio 1.51, 95% confidence interval, 1.03 to 2.24) and all-cause mortality (1.23, 1.00 to 1.50). No differences were observed for ischaemic stroke, cardiovascular death, or severe hypoglycaemia.

CONCLUSIONS

Sulfonylureas as second line drugs are associated with an increased risk of myocardial infarction, all cause mortality, and severe hypoglycaemia, compared with remaining on metformin monotherapy. Continuing metformin when introducing sulfonylureas appears to be safer than switching.

Dipeptidyl peptidase-4 inhibitors and incidence of inflammatory bowel disease among patients with type 2 diabetes: population based cohort study

OBJECTIVE

To assess whether the use of dipeptidyl peptidase-4 inhibitors is associated with the incidence of inflammatory bowel disease in patients with type 2 diabetes.

DESIGN

Population based cohort study.

SETTING

More than 700 general practices contributing data to the United Kingdom Clinical Practice Research Datalink.

PARTICIPANTS

A cohort of 141 170 patients, at least 18 years of age, starting antidiabetic drugs between 1 January 2007 and 31 December 2016, with follow-up until 30 June 2017.

MAIN OUTCOME MEASURES

Adjusted hazard ratios for incident inflammatory bowel disease associated with use of dipeptidyl peptidase-4 inhibitors overall, by cumulative duration of use, and by time since initiation, estimated using time dependent Cox proportional hazards models. Use of dipeptidyl peptidase-4 inhibitors was modelled as a time varying variable and compared with use of other antidiabetic drugs, with exposures lagged by six months to account for latency and diagnostic delays.

RESULTS

During 552 413 person years of follow-up, 208 incident inflammatory bowel disease events occurred (crude incidence rate of 37.7 (95% confidence interval 32.7 to 43.1) per 100 000 person years). Overall, use of dipeptidyl peptidase-4 inhibitors was associated with an increased risk of inflammatory bowel disease (53.4 v 34.5 per 100 000 person years; hazard ratio 1.75, 95% confidence interval 1.22 to 2.49). Hazard ratios gradually increased with longer durations of use, reaching a peak after three to four years of use (hazard ratio 2.90, 1.31 to 6.41) and decreasing after more than four years of use (1.45, 0.44 to 4.76). A similar pattern was observed with time since starting dipeptidyl peptidase-4 inhibitors. These findings remained consistent in several sensitivity analyses.

CONCLUSIONS

In this first population based study, the use of dipeptidyl peptidase-4 inhibitors was associated with an increased risk of inflammatory bowel disease. Although these findings need to be replicated, physicians should be aware of this possible association.

Pharmacologic Differences of Sulfonylureas and the Risk of Adverse Cardiovascular and Hypoglycemic Events

OBJECTIVE

Sulfonylureas have been associated with an increased risk of cardiovascular adverse events and hypoglycemia, but it is unclear if these risks vary with different agents. We assessed whether the risks of acute myocardial infarction, ischemic stroke, cardiovascular death, all-cause mortality, and severe hypoglycemia differ between sulfonylureas grouped according to pancreas specificity and duration of action.

RESEARCH DESIGN AND METHODS

Using the U.K. Clinical Practice Research Datalink, linked with the Hospital Episodes Statistics and the Office for National Statistics databases, we conducted a cohort study among patients with type 2 diabetes initiating monotherapy with sulfonylureas between 1998 and 2013. Adjusted hazard ratios (HRs) and 95% CIs were estimated using Cox proportional hazards models, comparing use of pancreas-nonspecific, long-acting sulfonylureas (glyburide/glimepiride) to pancreas-specific, short-acting sulfonylureas (gliclazide/glipizide/tolbutamide).

RESULTS

The cohort included 17,604 sulfonylurea initiators (mean [SD] follow-up 1.2 [1.5] years). Compared with specific, short-acting sulfonylureas (15,741 initiators), nonspecific, long-acting sulfonylureas (1,863 initiators) were not associated with an increased risk of acute myocardial infarction (HR 0.86; CI 0.55-1.34), ischemic stroke (HR 0.92; CI 0.59-1.45), cardiovascular death (HR 1.01; CI 0.72-1.40), or all-cause mortality (HR 0.81; CI 0.66-1.003), but with an increased risk of severe hypoglycemia (HR 2.83; CI 1.64-4.88).

CONCLUSIONS

The nonspecific, long-acting sulfonylureas glyburide and glimepiride do not have an increased risk of cardiovascular adverse events compared with the specific, short-acting sulfonylureas gliclazide, glipizide, and tolbutamide. However, nonspecific, long-acting sulfonylureas glyburide and glimepiride have an increased risk of severe hypoglycemia.

Testosterone replacement therapy and the risk of stroke in men: A systematic review

In recent years, questions have been raised regarding the cardiovascular safety of testosterone replacement therapy (TRT). The objective of this study was to systematically review the available evidence on TRT safety in men, specifically with respect to the risk of stroke. We identified publications from MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials up to May 2017. Articles eligible for review included observational studies evaluating TRT and the risk of stroke among men aged 18 or older. Randomized controlled trials (RCTs) comparing testosterone to placebo in men were also eligible, provided stroke was identified as an adverse event. Among seven cohort studies of hypogonadal men, one study reported that TRT was associated with a significant decrease in the risk of ischemic stroke (hazard ratio (HR) 0.64; 95% confidence interval (CI) 0.52-0.80). Another reported a similar decrease in risk (HR 0.64; 95% CI 0.43-0.96) among treated men who achieved normalized levels of testosterone. Limitations in study design, including immortal time bias and residual confounding, may have influenced both of these results. The remaining observational studies did not report measures of association to estimate the independent risk of stroke associated with TRT. Among eight RCTs, a low frequency of stroke events (<5) was observed across both testosterone and control groups, thus precluding any definitive conclusions. Based on these findings, the association between TRT and the risk of stroke in men remains unclear, and further large and methodologically robust studies are needed to establish this relationship.

The association between sclerostin and incident type 2 diabetes risk: a cohort study

OBJECTIVE

To determine whether sclerostin is associated with fasting glucose, insulin levels, insulin resistance or increased risk of incident type 2 diabetes.

BACKGROUND

Type 2 diabetic patients have a higher risk of fractures. Recent studies suggest sclerostin, a regulator of osteoblast activity, is associated with diabetes.

MATERIALS AND METHODS

Sclerostin levels were obtained from 1778 individuals with no history of type 2 diabetes participating in the population-based Canadian Multicentre Osteoporosis Study (CaMos) cohort. Participants were followed until diagnosis of type 2 diabetes, death or end of the study period (31 December 2013). The relationship of sclerostin with fasting glucose, insulin levels and homoeostatic model assessment-insulin resistance (HOMA-IR) was studied in linear regression models. Cox proportional hazards models were used to determine the association of sclerostin levels and the risk of incident type 2 diabetes during a mean 7·5 years of follow-up.

RESULTS

Fasting glucose, fasting insulin levels and HOMA-IR were weakly correlated with sclerostin levels (Spearman's correlation coefficient: 0·11, P < 0·05; -0·09, P < 0·05; and -0·07, P = 0·02, respectively). Multiple linear regression analyses confirmed a significant association between sclerostin and fasting insulin and HOMA-IR but no significant association with fasting glucose levels. Sclerostin levels were not found to be significantly associated with the risk of incident type 2 diabetes (HR: 1·30; 95% CI: 0·37-4·57).

CONCLUSIONS

We observed an association between sclerostin levels with fasting insulin levels and HOMA-IR, but there was no clear association with type 2 diabetes risk. Further studies are needed to understand the role of sclerostin in type 2 diabetes.

Blood lipids and prostate cancer: a Mendelian randomization analysis

Genetic risk scores were used as unconfounded instruments for specific lipid traits (Mendelian randomization) to assess whether circulating lipids causally influence prostate cancer risk. Data from 22,249 prostate cancer cases and 22,133 controls from 22 studies within the international PRACTICAL consortium were analyzed. Allele scores based on single nucleotide polymorphisms (SNPs) previously reported to be uniquely associated with each of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) levels, were first validated in an independent dataset, and then entered into logistic regression models to estimate the presence (and direction) of any causal effect of each lipid trait on prostate cancer risk. There was weak evidence for an association between the LDL genetic score and cancer grade: the odds ratio (OR) per genetically instrumented standard deviation (SD) in LDL, comparing high- (≥7 Gleason score) versus low-grade (<7 Gleason score) cancers was 1.50 (95% CI: 0.92, 2.46; P = 0.11). A genetically instrumented SD increase in TGs was weakly associated with stage: the OR for advanced versus localized cancer per unit increase in genetic risk score was 1.68 (95% CI: 0.95, 3.00; P = 0.08). The rs12916-T variant in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) was inversely associated with prostate cancer (OR: 0.97; 95% CI: 0.94, 1.00; P = 0.03). In conclusion, circulating lipids, instrumented by our genetic risk scores, did not appear to alter prostate cancer risk. We found weak evidence that higher LDL and TG levels increase aggressive prostate cancer risk, and that a variant in HMGCR (that mimics the LDL lowering effect of statin drugs) reduces risk. However, inferences are limited by sample size and evidence of pleiotropy.

The combination of DPP-4 inhibitors versus sulfonylureas with metformin after failure of first-line treatment in the risk for major cardiovascular events and death

OBJECTIVE

To determine whether the combination of dipeptidyl-peptidase 4 (DPP-4) inhibitors vs. sulfonylureas with metformin after failure of first-line treatment is associated with a decreased risk for major adverse cardiovascular events (myocardial infarction and stroke) and for all-cause mortality.

METHOD

Using the UK Clinical Practice Research Datalink, a cohort of patients newly treated with metformin or sulfonylurea monotherapy between January 1, 1988, and December 31, 2011, was identified and was followed until December 31, 2012. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models to compare the DPP-4 inhibitor-metformin combination to the sulfonylurea-metformin combination so as to study the risk for a composite endpoint consisting of myocardial infarction, stroke and all-cause mortality. The models were adjusted for high-dimensional propensity score deciles.

RESULTS

The cohort consisted of 11,807 patients that included 2286 on a DPP-4 inhibitor-metformin combination and 9521 on a sulfonylurea-metformin combination. The crude incidence rates (95% CIs) of the composite endpoint were 1.2% (0.8% to 1.7%) and 2.2% (1.9% to 2.5%) per year for the DPP-4 inhibitor-metformin and sulfonylurea-metformin combinations, respectively. In the high-dimensional propensity score-adjusted model, the use of the DPP-4 inhibitor-metformin combination was associated with a 38% decreased risk for the composite endpoint (adjusted HR: 0.62; 95% CI 0.40 to 0.98), compared with the sulfonylurea-metformin combination.

CONCLUSIONS

The use of a DPP-4 inhibitor combination with metformin, compared with a sulfonylurea-metformin combination, was associated with decreased risks for major cardiovascular events and all-cause mortality.

Incretin-based drugs and the risk of congestive heart failure

OBJECTIVE

To determine whether the use of incretin-based drugs, including GLP-1 analogs and dipeptidyl peptidase-4 inhibitors, is associated with an increased risk of congestive heart failure (CHF) among patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

The U.K. Clinical Practice Research Datalink, linked to the Hospital Episode Statistics database, was used to conduct a cohort study with a nested case-control analysis among patients newly prescribed antidiabetic drugs between 1 January 2007 and 31 March 2012 and no prior history of CHF. Case subjects were defined as patients hospitalized for a first CHF and matched with up to 20 control subjects on age, duration of treated diabetes, calendar year, and time since cohort entry. Conditional logistic regression was used to estimate odds ratios (ORs) with corresponding 95% CIs of incident CHF comparing current use of incretin-based drugs with current use of two or more oral antidiabetic drugs.

RESULTS

The cohort consisted of 57,737 patients followed for a mean 2.4 years, during which time 1,118 incident cases of hospitalized CHF were identified (incidence rate 8.1/1,000 person-years). Current use of incretin-based drugs was not associated with an increased risk of CHF (adjusted OR 0.85 [95% CI 0.62-1.16]). Secondary analyses revealed no duration-response relationship (P trend = 0.39).

CONCLUSIONS

In our population-based study, incretin-based drug use was not associated with an increased risk of CHF among patients with type 2 diabetes. These findings provide some reassurance, but will need to be replicated in other large-scale studies.

Metformin and low levels of thyroid-stimulating hormone in patients with type 2 diabetes mellitus

BACKGROUND

Small cross-sectional studies have suggested that metformin, a first-line oral hypoglycemic agent, may lower thyroid-stimulating hormone (TSH) levels. Our objective was to determine whether the use of metformin monotherapy, when compared with sulfonylurea monotherapy, is associated with an increased risk of low TSH levels (<0.4 mIU/L) in patients with type 2 diabetes mellitus.

METHODS

Using the Clinical Practice Research Datalink, we identified patients who began receiving metformin or sulfonylurea monotherapy between Jan. 1, 1988, and Dec. 31, 2012. We assembled 2 subcohorts of patients with treated hypothyroidism or euthyroidism, and followed them until Mar. 31, 2013. We used Cox proportional hazards models to evaluate the association of low TSH levels with metformin monotherapy, compared with sulfonylurea monotherapy, in each subcohort.

RESULTS

A total of 5689 patients with treated hypothyroidism and 59,937 euthyroid patients were included in the subcohorts. Among patients with treated hypothyroidism, 495 events of low TSH levels were observed during follow-up (incidence rate 119.7/1000 person-years). In the euthyroid group, 322 events of low TSH levels were observed (incidence rate 4.5/1000 person-years). Compared with sulfonylurea monotherapy, metformin monotherapy was associated with a 55% increased risk of low TSH levels in patients with treated hypothyroidism (incidence rate 79.5/1000 person-years v. 125.2/1000 person-years, adjusted hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.09-2.20), with the highest risk in the 90-180 days after initiation (adjusted HR 2.30, 95% CI 1.00-5.29). No association was observed in euthyroid patients (adjusted HR 0.97, 95% CI 0.69-1.36).

INTERPRETATION

In this longitudinal population-based study, metformin use was associated with an increased incidence of low TSH levels in patients with treated hypothyroidism, but not in euthyroid patients. The clinical consequences of this need further investigation.

An assessment of the shared allelic architecture between type II diabetes and prostate cancer

BACKGROUND

To determine whether the alleles that influence type II diabetes risk and glycemic traits also influence prostate cancer risk.

METHODS

We used a multiple single-nucleotide polymorphisms (SNP) genotypic risk score to assess the average effect of alleles that increase type II diabetes risk or worsen glycemic traits on risk of prostate cancer in 19,662 prostate cancer cases and 19,715 controls from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortium and 5,504 prostate cancer cases and 5,834 controls from the Cancer Research UK (CRUK) prostate cancer study.

RESULTS

Calculating the average additive effect of type II diabetes or glycemic trait risk alleles on prostate cancer risk using a logistic model revealed no evidence of a shared allelic architecture between type II diabetes, or worsened glycemic status, with prostate cancer risk [OR for type II diabetes alleles: 1.00 (P = 0.58), fasting glycemia alleles: 1.00 (P = 0.67), HbA1c alleles: 1.00 (P = 0.93), 2-hour OGTT alleles: 1.01 (P = 0.14), and HOMA-B alleles: 0.99 (P = 0.57)].

CONCLUSIONS

Using genetic data from large consortia, we found no evidence for a shared genetic etiology of type II diabetes or glycemic risk with prostate cancer.

IMPACT

Our results showed that alleles influencing type II diabetes and related glycemic traits were not found to be associated with the risk of prostate cancer.

Articular aspergillosis: case report and review of the literature

The incidence of invasive aspergillosis is increasing due to more frequent use of immunosuppressant agents in patients with autoimmune diseases, hematological malignancies, and solid organ and hematopoietic stem cell transplants. Invasive aspergillosis most commonly affects the lungs, sinuses, and brain. Aspergillosis affecting the musculoskeletal system is rare. We describe here a case of articular aspergillosis in a febrile neutropenic patient successfully treated with voriconazole and caspofungin, and briefly review the 10 cases of articular aspergillosis that have previously been described in the literature.