Lower frequency of comorbidities prior to onset of giant cell arteritis; a population-based study

To assess the frequency of comorbidities and metabolic risk factors at and prior to GCA diagnosis.Retrospective case-control study of patients with incident GCA between 1/1/2000 and 12/31/2019 in Olmsted County, MN. Two age- and sex-matched controls were identified, and each assigned an index date corresponding to an incidence date of GCA. Medical records were manually abstracted for comorbidities and laboratory data at incidence date, 5-years, and 10-years prior to incidence date. Twenty-five chronic conditions using ICD-9 diagnosis codes were also studied at incidence date and 5 years prior to incidence date.129 patients with GCA (74% female) and 253 controls were identified. At incidence date, the prevalence of diabetes mellitus (DM) was lower among GCA patients (5% vs 17%; p=0.001). At 5 years prior to incidence date, patients were less likely to have DM (2% vs 13%; p<0.001) and hypertension (27% vs 45%; p=0.002) and had a lower mean number (SD) of comorbidities [0.7 (1.0) vs [1.3 (1.4)] (p<0.001)] compared to controls. Moreover, patients had significantly lower median fasting blood glucose (FBG) (96 vs 104 mg/dL; p <0.001) and body mass index (BMI) (25.8 vs 27.7 kg/m2p=0.018) compared to controls. Multivariable logistic regression analysis revealed negative associations for FBG with GCA at 5 and 10 years prior to diagnosis/index date.DM prevalence and median FBG and BMI were lower in patients with GCA up to 5 years prior to diagnosis, suggesting that metabolic factors influence the risk of GCA.