Prevalence of diabetes mellitus in biopsy-positive giant cell arteritis

Impact of diabetes, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker use, and statin use on presentation and outcomes in patients with giant cell arteritis

AIM

Few, separate, small retrospective studies in giant cell arteritis (GCA) reported that patients: (a) with diabetes mellitus had less positive temporal artery biopsies (TAB); (b) on angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin II receptor blockers (ARB) experienced fewer relapses; and (c) on statins experienced the same frequency of clinical complications and relapses as non-exposed patients. This retrospective chart review study simultaneously investigated the impact of these 3 factors on a cohort of patients followed in 2 large Canadian centers (Hamilton and Toronto, ON).

METHODS

One hundred and thirty-seven patients diagnosed with GCA between 1993 and 2015 were included in the study. Presenting symptoms, TAB results, disease complications and outcomes (relapses, duration of glucocorticoid use) were compared between exposed (diabetes/ACE/ARB/statin) and non-exposed patients, with adjustment for main potential confounding variables.

RESULTS

Temporal artery biopsies was less often positive in patients with pre-existing diabetes (relative risk 0.24; 95% CI: 0.069-0.81). Patients who developed diabetes after diagnosis had a lower relapse-free survival (adjusted hazards ratio [HR] 0.28; 95% CI: 0.095-0.84). Patients taking ARBs prior to diagnosis were more likely to successfully discontinue glucocorticoids without a flare in the following 3 months (adjusted HR 2.46; 95% CI: 1.2-5.3). Clinical complications and relapse rates did not differ between patients on statin therapy or not.

CONCLUSION

Diabetic patients with GCA were less likely to have a positive TAB, and more likely to relapse. ARB therapy prior to diagnosis showed an association with success at discontinuing glucocorticoids. Statin therapy did not alter the clinical presentation or course of GCA.

The relationship between glycated haemoglobin levels and the risk of giant cell arteritis - a case-control study

Objectives

The EULAR core dataset for observational studies in GCA does not include glycated haemoglobin (HbA_1c). A multivariable score to stratify the pre-test probability of GCA also does not include HbA_1c. There have been contradictory reports about diabetes mellitus being a risk factor for GCA. We report the first study analysing the relationship of pre-diagnosis HbA_1c with the risk of GCA.

Methods

This was a single-centre retrospective case–control study conducted in Norfolk, UK. All GCA cases were diagnosed with imaging or biopsy. Each case was assigned two age- and sex-matched controls. The primary outcome measure was the glycaemic status (HbA_1c categorized into euglycaemia, pre-diabetes or diabetes mellitus) at diagnosis between cases and controls. The HbA_1c was compared between two groups using the Mann–Whitney U test. The glycaemic categorization was compared using the χ² test.

Results

One hundred and twelve cases and 224 controls were included. The median (interquartile range) of HbA_1c of cases and controls was 40 (37, 43) and 41 (39, 47) mmol/mol (P < 0.001), respectively. Ten of 112 cases and 52 of 224 controls had diabetes mellitus. The χ² test demonstrated a significant interaction between glycaemic state and GCA (P = 0.006). Individuals with diabetes mellitus had an odds ratio (95% CI) of 0.32 (0.13, 0.74) (P = 0.008) of having GCA compared with euglycaemic individuals.

Conclusion

HbA_1c in the diabetic range reduces the probability of GCA. HbA_1c should be considered in any multivariable score to calculate the risk of GCA, and in future development of diagnostic and classification criteria. There is a need for an epidemiological study looking at the possibility of a protective nature of diabetes mellitus against GCA or whether it is only a mimic.

Association between glucocorticoid therapy and incidence of diabetes mellitus in polymyalgia rheumatica and giant cell arteritis: a systematic review and meta-analysis

Background

Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are almost always treated with glucocorticoids (GCs), but long-term GC use is associated with diabetes mellitus (DM). The absolute incidence of this complication in this patient group remains unclear.

Objective

To quantify the absolute risk of GC-induced DM in PMR and GCA from published literature.

Methods

We identified literature from inception to February 2017 reporting diabetes following exposure to oral GC in patients with PMR and/or GCA without pre-existing diabetes. A random-effects meta-analysis was performed to summarise the findings.

Results

25 eligible publications were identified. In studies of patients with GCA, mean cumulative GC dose was almost 1.5 times higher than in studies of PMR (8.2 g vs 5.6 g), with slightly longer treatment duration and longer duration of follow-up (6.4 years vs 4.4 years). The incidence proportion (cumulative incidence) of patients who developed new-onset DM was 6% (95% CI 3% to 9%) for PMR and 13% (95% CI 9% to 17%) for GCA. Based on UK data on incidence rate of DM in the general population, the expected background incidence rate of DM over 4.4 years in patients with PMR and 6.4 years in patients with GCA (follow-up duration) would be 4.8% and 7.0%, respectively. Heterogeneity between studies was high (I²=79.1%), as there were differences in study designs, patient population, geographical locations and treatment. Little information on predictors of DM was found.

Conclusion

Our meta-analysis produced plausible estimates of DM incidence in patients with PMR and GCA, but there is insufficient published data to allow precise quantification of DM risk.

Giant cell arteritis and vascular disease-risk factors and outcomes: a cohort study using UK Clinical Practice Research Datalink

Objective

To evaluate the associations between GCA and vascular diseases and other comorbidities in patients with GCA compared with non-vasculitis patients.

Methods

Using the UK-based Clinical Practice Research Datalink we identified 9778 newly diagnosed GCA patients in 1990-2014, and up to 10 non-vasculitis patients randomly matched to each case on age, sex, practice and years of history before cohort entry. We compared the distributions of 9 different pre-existing vascular diseases and 11 other comorbidities, and risks of incident vascular diseases and other comorbidities after cohort entry between GCA and non-vasculitis patients.

Results

Patients with GCA were more likely to have a history of vascular diseases and other comorbidities except myocardial infarction, type 2 diabetes, obesity and cancer, compared with non-vasculitis patients. Patients with GCA had increased risks for all types of incident vascular disease compared with non-vasculitis patients: adjusted hazard ratios were 1.57 (95% CI: 1.36, 1.82) for myocardial infarction, 1.41 (95% CI: 1.29, 1.55) for stroke, 1.75 (95% CI: 1.49, 2.06) for peripheral vascular disease, 1.98 (95% CI: 1.50, 2.62) for aortic aneurysm and 2.03 (95% CI: 1.77, 2.33) for venous thromboembolism. Patients with GCA also had increased risks for other incident comorbidities (type 2 diabetes, depression, etc.), but not for cancer.

Conclusion

Patients with GCA had more prior vascular diseases and other comorbidities before the diagnosis and they also had increased risks for incident vascular diseases and many other incident comorbidities after the diagnosis compared with non-vasculitis population.

Diagnostic Algorithm for Patients With Suspected Giant Cell Arteritis

BACKGROUND

To identify clinical and laboratory factors contributing to the diagnosis of giant cell arteritis (GCA) and develop a diagnostic algorithm for the evaluation of GCA.

METHODS

Retrospective review of 213 consecutive cases of temporal artery biopsy (TAB) seen at a single academic center over a 10-year period (2000-2009). Pathologic specimens were re-reviewed and agreement between the original and second readings was assessed. A composite clinical suspicion score was created by adding 1 point for each of the following criteria: anterior extracranial circulation ischemia, new onset headache, abnormal laboratory results (erythrocyte sedimentation rate, C-reactive protein (CRP), or platelet count), jaw claudication, abnormal or tender superficial temporal artery, constitutional symptoms, and polymyalgia rheumatica; one point was subtracted if a comorbid condition could explain a criterion.

RESULTS

Of the 204 TABs analyzed, pathologic findings were confirmatory in 49 (24.0%) and suggestive in 12 (5.9%). TAB-positive patients were more likely to be older (age 75.2 ± 7.8 vs 69.7 ± 11.0 years, P = 0.0002), complain of jaw claudication (relative-risk = 3.26, P = 0.0014), and have thrombocytosis (relative-risk = 3.3, P = 0.0072) and elevated CRP (relative-risk = 1.8, P = 0.037). None of the patients with a clinical score less than 2 had a positive TAB. Diabetes mellitus and kidney disease were often the explanation for the symptoms and abnormal clinical finding(s) that led to a negative TAB.

CONCLUSIONS

We propose a clinical algorithm that is highly predictive for a positive TAB and can be valuable in the evaluation process of suspected cases of GCA.

Effect of diabetes mellitus on giant cell arteritis

BACKGROUND

To determine if Type 2 diabetes mellitus (DM) is protective against giant cell arteritis (GCA) and to estimate the incidence of GCA diagnosis from Medicare claims.

METHODS

Medicare 5% claims files from 1991 to 2011 were used to identify beneficiaries diagnosed with DM, but not GCA, within a 3-year ascertainment period. Propensity score matching was used to define a control group of nondiabetics with comparable demographic covariates. Competing risk regression was then used to assess the impact of DM diagnosis on GCA diagnosis. To allow for a 3-year ascertainment period, the analysis sample was limited to beneficiaries older than 68 years at baseline.

RESULTS

A total of 151,041 beneficiaries diagnosed with DM were matched to an equal number of controls. Mean study follow-up was 67.75 months. GCA was diagnosed among 1116 beneficiaries with DM (0.73%) vs 465 (0.30%) controls. The risk of receiving a GCA diagnosis among patients with DM was increased by 100% (subhazard ratio, 2.00; 95% confidence interval, 1.78-2.25). The annual incidence of GCA diagnosis among claims for US Medicare beneficiaries older than 68 years old was 93 in 100,000.

CONCLUSIONS

A DM diagnosis is not protective against a GCA diagnosis in the Medicare population. Our data suggest that a DM diagnosis increases the risk of GCA diagnosis within 5.7 years for Medicare beneficiaries older than 68 years.

Lower body mass index is associated with a higher risk of giant cell arteritis: a systematic review and meta-analysis

OBJECTIVE

To characterize the possible association between body mass index (BMI) and risk of giant cell arteritis (GCA).

METHODS

We conducted a systematic review of observational studies (case-control or cohort study) that (I) reported BMI of patients with GCA prior to the diagnosis of GCA compared with subjects without GCA and (II) provided relative risk (RR), odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) from its regression analysis. Meta-analysis of the included studies was then performed to estimate the pooled effect using generic variance method of DerSimonian and Laird.

RESULTS

Three studies encompassing 141 patients with GCA and 85,736 controls met our eligibility criteria and were included in the data analyses. We demonstrated a statistically significant inverse relationship between BMI and risk of subsequent development of GCA as the risk increased by 8% when BMI was reduced by 1.0 kg/m(2) (pooled OR of 0.92/kg/m(2); 95% CI, 0.88-0.96).

CONCLUSIONS

Our study demonstrated a statistically significant inverse relationship between BMI and risk of subsequent development GCA. The pathophysiologic link behind this negative correlation is not well-characterized and further investigation is required.

Patients with giant cell arteritis have a lower prevalence of diabetes mellitus: A systematic review and meta-analysis

OBJECTIVE

The aim of this study is to compare the prevalence of diabetes mellitus (DM) in patients who are recently diagnosed with giant cell arteritis (GCA) with age- and sex-matched controls.

METHODS

We conducted a systematic review and meta-analysis of observational studies that (1) consisted of GCA cohort and non-GCA cohort that was randomly selected from the same population and (2) provided prevalences of DM at the time of diagnosis for patients with GCA and at the index date for controls. Pooled odds ratios and 95% confidence intervals (CIs) were calculated using a random-effect, Mantel-Haenszel analysis.

RESULTS

Five studies with 903 patients with GCA and 1064 controls were identified and included in our data analysis. We demonstrated a statistically significant lower prevalence of DM among patients with GCA with the pooled OR of 0.74 (95% CI, 0.57-0.97).

CONCLUSION

At diagnosis, patients with GCA had a lower prevalence of DM. Whether DM could be a protective factor against the development of GCA needs further investigations.

Cardiovascular risk and acute coronary syndrome in giant cell arteritis: a population-based retrospective cohort study

OBJECTIVE

To assess the occurrence of acute coronary syndrome (ACS) in patients with giant cell arteritis (GCA) compared to subjects without GCA.

METHODS

We retrospectively reviewed a population-based incidence cohort of Olmsted County, Minnesota residents with GCA diagnosed in 1950-2009. We compared this cohort with a cohort of patients without GCA of similar age, sex, and calendar year from the same population.

RESULTS

The study included 245 patients with GCA and 245 non-GCA subjects. The mean ± SD Framingham cardiovascular risk score was 30% ± 19% in GCA patients and 34% ± 23% in non-GCA subjects (P = 0.096) at the incidence/index date. Diabetes mellitus was significantly less common in GCA patients than non-GCA subjects at the index date. The mean high-density lipoprotein was higher and triglycerides were lower, with fewer patients taking lipid-lowering medications in the GCA cohort compared to the non-GCA cohort at the index date. During followup, no difference between the 2 cohorts was noted in the overall rate of ACS events (hazard ratio 0.74, 95% confidence interval 0.44-1.26). Overall thrombosis in myocardial infarction scores were similar in both cohorts. Revascularization procedures were done less frequently in GCA than in non-GCA subjects (19% versus 50%; P = 0.015). Post-ACS hospital length of stays and complications were similar in both cohorts.

CONCLUSION

Multiple cardiovascular risk factors are less atherogenic at incidence of GCA. There is no overall increased risk of ACS in patients with GCA.

Hospitalization rates and utilization among patients with giant cell arteritis: A population-based study from 1987 to 2012

BACKGROUND

Patients with giant cell arteritis (GCA) may experience serious vascular and visual complications. It is unknown, however, to what extent the difficulties of the disease may lead to hospitalization. The goal of this study is to discern whether patients with GCA are at greater risk for all-cause hospitalizations when compared to the general population.

METHODS

This retrospective, population-based cohort study utilized patients with large vessel or visual involvement who were diagnosed with GCA (as defined by the 1990 ACR criteria) between 1/1/1950 and 12/31/2009, and a reference cohort of patients without GCA matched on age, sex, and calendar year. Each patients' medical record was examined for hospitalizations from 1987 through 2012. For this analysis, follow-up began with the latter of index date or 1/1/1987 and ended at the earlier of death, emigration from Olmsted County, or 12/31/2012. Discharge diagnoses were grouped together using the Clinical Classifications Software (CCS) for ICD-9-CM from Healthcare Cost and Utilization Project (HCUP). Data were analyzed using person-year methods and rate ratios comparing GCA to non-GCA.

RESULTS

The GCA cohort consists of 199 patients with a mean age of 76.2 (79.9% female) and follow-up of 8.2 years. The non-GCA cohort is comprised of 194 patients with a mean age of 75.7 (78.9% female) and follow-up of 8.6 years. The patients with GCA had 816 hospitalizations and the non-GCA patients had 737 hospitalizations. GCA patients proved to be at a marginally greater risk for all causes of hospitalization [rate ratio (RR) = 1.13; 95% confidence interval (CI): 1.02-1.25]; however, the rate of hospitalization for patients with and without GCA decreased significantly from 1987 to 2012. Two specific discharge categories are of interest. First, transient cerebral ischemia is a greater risk of hospitalization for patients with GCA who had 16 hospitalizations compared to patients without GCA who only had 5 hospitalizations (RR = 3.06; 95% CI: 1.27-9.47). Second, patients with GCA (21 hospitalizations) are at greater risk of hospitalization for syncope than patients without GCA (5 hospitalizations) (RR = 3.98; 95% CI: 1.72-12.14).

CONCLUSION

In this first ever analysis of all-cause hospitalizations in a population-based cohort, patients with GCA appear to be at a marginally greater risk for hospitalization than patients without GCA, although the rate of hospitalization for GCA patients decreased from 1987 to 2012. Patients with GCA are at increased risk of hospitalization for both transient cerebral ischemia and syncope.

Coronary artery disease in giant cell arteritis: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between giant cell arteritis (GCA) and risk of coronary artery disease (CAD).

METHODS

We conducted a systematic review and meta-analysis of observational studies that reported relative risks, hazard ratios, or standardized incidence ratios with 95% confidence interval comparing CAD risk in patients with GCA versus non-GCA controls. Pooled risk ratios and 95% confidence intervals were calculated using a random-effect, generic inverse variance of DerSimonian and Laird.

RESULT

Six studies with 10,868 patients with GCA and 245,323 controls were identified and included in our data analysis. The pooled risk ratio of CAD in patients with GCA was 1.51 and did not achieve statistical significance (95% CI: 0.88-2.61). The statistical heterogeneity was high with an I(2) of 97%.

CONCLUSION

In contrast to other chronic systemic inflammatory disorders, our meta-analysis did not show any statistically significant increased risk of CAD among patients with GCA.

Hospitalized infections in giant cell arteritis: a population-based retrospective cohort study

OBJECTIVE

To assess the occurrence of infections requiring or acquired during hospitalization in patients with giant cell arteritis (GCA).

METHODS

We retrospectively reviewed a population-based incidence cohort of patients with GCA diagnosed between 1950 and 2009 and compared this cohort with a non-GCA one matched for age, sex, and calendar year from the same population.

RESULTS

We identified 245 patients in the GCA cohort and 245 patients in the non-GCA cohort. Seventy-four GCA subjects (134 episodes) and 79 non-GCA (153 episodes) had infections requiring or acquired during hospitalization [rate ratio (RR) 0.94; 95% CI 0.74, 1.18]. Sixty-seven subjects (107 episodes) in the GCA cohort and 63 subjects (110 episodes) in non-GCA cohort required hospitalization secondary to an infection (RR 1.04; CI 0.80, 1.36). Pneumonia, urinary tract infections (UTI), skin and soft tissue infections accounted for the majority of infections requiring hospitalization and had similar occurrence in both cohorts. UTI accounted for the majority of infections requiring hospitalization in the first 6 months after GCA incidence (RR 3.93; CI 0.85, 56.52). No difference between the 2 cohorts was noted in overall infections acquired during hospitalization (RR 0.68; CI 0.41, 1.08).

CONCLUSION

There is no overall increased risk of infections requiring or acquired during hospitalization in patients with GCA who are taking glucocorticoid therapy. There may be an increased risk of infections requiring hospitalization, especially of the urinary tract, in the first 6 months after GCA incidence, although this did not achieve statistical significance in our study.