Association between decreasing estimated glomerular filtration rate and risk of cardiac conduction defects in patients with type 2 diabetes.

AIM: We aimed to assess the association between decreasing estimated glomerular filtration rate (eGFR) or abnormal albuminuria and the risk of certain cardiac conduction defects in patients with type 2 diabetes mellitus (T2DM). METHODS: We examined a hospital-based sample of 923 patients with T2DM discharged from our Division of Endocrinology over the years 2007-2014. Standard electrocardiograms (ECGs) were performed in all patients. eGFR was estimated by using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, whilst albuminuria was measured by an immuno-nephelometric method on morning spot urine samples. RESULTS: A total of 253 (27.4%) patients had some type of cardiac conduction defects on standard ECGs (defined as at least one heart block among first-degree atrioventricular block, second-degree block, third-degree block, left bundle branch block, right bundle branch block, left anterior hemi-block or left posterior hemi-block). Prevalence of patients with eGFRCKD-EPI < 30 mL/min/1.73 m2, eGFRCKD-EPI 59-30 mL/min/1.73 m2 or abnormal albuminuria (i.e. urinary albumin-to-creatinine ratio ≥ 30 mg/g) were 7.0%, 29.4% and 41.3%, respectively. After adjustment for known cardiovascular risk factors, diabetes-related variables and potential confounders, there was a significant, graded association between decreasing eGFR values and risk of any cardiac conduction defects [adjusted-odds ratios of 2.05 (95% CI: 1.2-3.5), 2.85 (95% CI: 1.6-5.1) and 3.62 (95% CI: 1.6-8.1) for eGFRCKD-EPI 89-60, eGFRCKD-EPI 59-30 and eGFRCKD-EPI < 30 mL/min/1.73 m2, respectively]. Conversely, abnormal albuminuria was not independently associated with an increased risk of any conduction defects (adjusted-odds ratio: 1.09, 95% CI: 0.7-1.6). CONCLUSION: Decreasing eGFR is independently associated with an increased risk of cardiac conduction defects in hospitalized patients with T2DM.

Hyperuricemia is associated with an increased prevalence of paroxysmal atrial fibrillation in patients with type 2 diabetes referred for clinically indicated 24-h Holter monitoring.

PURPOSE: Several studies have reported an association between hyperuricemia and increased risk of permanent atrial fibrillation (AF) in patients with and without type 2 diabetes mellitus (T2DM). Currently, no published data are available on the relationship between hyperuricemia and risk of paroxysmal AF. METHODS: We retrospectively evaluated 245 T2DM outpatients without pre-existing AF, cancer, cirrhosis and end-stage renal disease, who underwent a 24-h ECG-Holter monitoring for various clinical indications. Hyperuricemia was defined as a serum uric acid level >7 mg/dl for men and >6 mg/dl for women or allopurinol use. The diagnosis of paroxysmal AF was confirmed in affected individuals on the basis of 24-h ECG-Holter monitoring by experienced cardiologists. RESULTS: Hyperuricemia was observed in 59 (24.1%) patients, whereas paroxysmal AF was found in 11 (4.5%) patients. The prevalence of paroxysmal AF was higher in patients with hyperuricemia than in those without hyperuricemia (10.2 vs. 2.7%, p = 0.026). Logistic regression analysis showed that hyperuricemia was associated with an increased risk of prevalent paroxysmal AF. This association remained significant even after adjustment for age, metabolic syndrome and chronic kidney disease (adjusted-odds ratio 4.01, 95% CI 1.08-14.9; p = 0.039). Similar results were found when we used serum uric acid levels as a continuous measure. CONCLUSIONS: This study shows for the first time that hyperuricemia is independently associated with an approximately fourfold increased risk of prevalent paroxysmal AF in patients with T2DM. These findings may partly explain the increased risk of permanent atrial fibrillation and cardiovascular death observed among patients with hyperuricemia.

Hyperuricemia is associated with an increased prevalence of atrial fibrillation in hospitalized patients with type 2 diabetes.

PURPOSE: Hyperuricemia/gout and atrial fibrillation (AF) are two pathological conditions that are highly prevalent in type 2 diabetes and share multiple cardiovascular risk factors. However, the relationship between elevated levels of serum uric acid and risk of AF in type 2 diabetes is currently poorly known. METHODS: We studied a hospital-based sample of 842 (male/female = 463/379) patients with type 2 diabetes discharged from our Division of Endocrinology during 2007-2011. Hyperuricemia was defined as a serum uric acid level >7 mg/dl for men and >6 mg/dl for women or allopurinol use. The diagnosis of AF was confirmed in affected participants on the basis of ECGs and medical history by experienced cardiologists. RESULTS: Overall, 243 (28.9 %) patients had hyperuricemia and 91 (10.8 %) patients had persistent or permanent AF. Compared with those with normal serum uric acid levels, patients with hyperuricemia had a remarkably greater prevalence of AF (20.6 vs. 7.1 %; p < 0.001). Hyperuricemia was significantly associated with an increased risk of prevalent AF (odds ratio 3.41, 95 % CI 2.19-5.32; p < 0.001). Adjustments for age, sex, smoking, hemoglobin A1c, hypertension status, chronic kidney disease, chronic obstructive pulmonary disease and previous histories of hyperthyroidism, ischemic heart disease and valvular heart diseases did not weaken this association (adjusted-odds ratio 6.27, 95 % CI 1.82-21.5; p < 0.01). CONCLUSIONS: These results indicate that hyperuricemia is associated with an increased prevalence of AF in hospitalized patients with type 2 diabetes, independently of multiple risk factors and potential confounders.