Cardiovascular, Renal Outcomes in Type 1 Diabetes
More awareness for afib risk factors including age, severity of complications, and glycemic status are needed.
Patients with type 1 diabetes are at an increased risk for atrial fibrillation (AF), and the risk is greater in women than in men, according to a recent study published in the Lancet Diabetes and Endocrinology.
In the first prospective study investigating the connection between AF and type 1 diabetes, Sofia Dahlqvist, from the Department of Medicine at the NU Hospital Group in Uddevalla, Sweden, and colleagues gathered data on 36,258 patients with type 1 diabetes and 179,980 individuals without diabetes from the Swedish National Diabetes Register and the Swedish National Patient Registry. Researchers calculated the incidences of AF through sex, age, glycemic control (as measured by mean glycated hemoglobin [HbA1C]), and renal complication (assessed via normoaluminuria and microaluminuria) variables.
During the follow-up period of 9.7 years for the type 1 diabetes group and 10.2 years for the control group, 749 participants with diabetes (2%) and 2882 control participants (2%) were diagnosed with AF, with an adjusted hazard ratio (HR) of 1.13 in men (95% CI, 1.01-1.25; P =.029) and an HR of 1.50 in women (95% CI, 1.30-1.72; P <.0001).
The researchers noted differences between increased risk and sex and completed further analyses for men and women separately. In an age-adjusted analysis, the HR for AF was 1.29 in men with type 1 diabetes (95% CI, 1.16-1.43; P <.0001) and 1.74 in women with type 1 diabetes (95% CI, 1.52-1.98; P <.0001). The risk for AF in men aged 35 to 49 years was 1.42 (95% CI, 1.10-1.84; P =.0075), which was higher than in men aged 18 to 34 years, 50 to 64 years, or 65 years or older. Women aged 50 to 64 years (95% CI, 1.60; 95% CI, 1.27-2.03; P <.0001) and 65 years and older (HR, 1.34; 95% CI, 1.12-1.62; P =.0019) had higher risk for AF, whereas younger women had no increased risk.
Patients with worsening glycemic control or higher HbA1C (defined as values of ≥9.7% [≥83 mmol/mol]) also had an increased risk for AF; in men, the HR was 2.20 (95% CI, 1.60-3.02; P <.0001) vs 2.62 in women (95% CI, 1.72-3.98; P <.0001).
AF risk was significantly increased for women with renal complications. Individuals with normoalbuminuria had an increased HR of 1.32 (95% CI, 1.10-1.57; P =.0023), and those with microalbuminuria had an increased HR of 1.58 (95% CI, 1.17-2.12; P =.0028). AF risk was not increased in men with normoalbuminuria or microalbuminuria.
"[C]linicians should be more aware of risk factors for atrial fibrillation such as older age, severity of renal complications, poor glycemic control, hypertension, and coexisting cardiovascular disease," the researchers recommended.
These findings may be limited because of the difficulty of determining AF onset as well as the probability that patients with type 1 diabetes have more regularly schedule clinic visits where AF can be detected.
Disclosures: This study was funded by grants from the Novo Nordisk Foundation, among other organizations. The researchers report receiving financial support from the Novo Nordisk Foundation, Novo Nordisk, AstraZeneca, Dexcom, Eli Lily, Rubin Medical, Boehringer Ingelheim, Amgen, Merck, GlaxoSmithKline, and Sanofi, among others.
Dahlqvist S, Rosengren A, Gudbjörnsdottir S, et al. Risk of atrial fibrillation in people with type 1 diabetes compared with matched controls from the general population: a prospective case-control study [published online August 21, 2017]. Lancet Diabetes Encdocrinol. doi:10.1016/S2213-8587(17)30262-0