Body mass index is associated with prognosis in Japanese elderly patients with atrial fibrillation: an observational study from the outpatient clinic

Abstract

The relationship between body mass index (BMI) and the prognosis of elderly patients with atrial fibrillation (AF) is unknown. We aimed to examine the association of body weight with the clinical outcomes among Japanese elderly patients with a history of documented AF. This observational study of AF patients from an outpatients clinic in Nagoya University Hospital included 413 patients ≥70 years old (99 obese: BMI ≥25 kg/m(2); 256 normal weight: BMI 18.5-24.9 kg/m(2); and 58 underweight patients: BMI <18.5 kg/m(2)). The mean age was 77.5 ± 5.6 years. During a mean follow-up of 19.0 months, all-cause death occurred in 23 patients (obese 1 %, normal weight 5.1 %, and underweight 16 %). The major adverse events including all-cause death, stroke or transient ischemic attack, heart failure requiring admission, and acute coronary syndrome were observed in 53 patients (obese 5.1 %, normal weight 13 %, and underweight 26 %). After adjusting for confounding factors, the underweight group had a significantly greater risk for all-cause death [hazard ratio (HR) 2.91, 95 % confidence interval (CI) 1.12-7.60, p = 0.029], and major adverse events (HR 2.45, 95 % CI 1.25-4.78, p = 0.009) than the normal weight group. In contrast, the obese group had a better prognosis in major adverse events compared with the normal weight group (HR 0.34, 95 % CI 0.13-0.89, p = 0.029). In conclusion, lower BMI was independently associated with poor outcomes among older AF patients. The association between obesity and better prognosis in elderly AF patients was also found.

Is There an Obesity Paradox for Outcomes in Atrial Fibrillation?

“…18 In this study, underweight patients were at higher risk for both major adverse events and allcause death. 18 In a subgroup analysis from the Japanese Rhythm Management Trial for Atrial Fibrillation (J-RHYTHM) registry, underweight patients were at higher risk for both cardiovascular death (HR, 2.91; 95% CI, 1.47-5.75; P=0.002) and all-cause death (HR, 2.40; 95% CI, 1.59-3.63; P<0.001), whereas overweight patients had lower risk for all-cause death (HR, 0.60; 95% CI, 0.37-0.95). 23 No significant association was found for the obese patients nor any influence of body weight in determining thromboembolism and major bleeding.…”

“…21 Four observational studies were based on Asian populations. [17][18][19]23 In 12 out of 13 studies, the mean age progressively decreased with higher BMI categories, with the study by Overvad et al 16 being the exception (Table). In 2016 alone, 6 other studies were published examining the relationship of BMI with outcomes in AF.…”

“…19 Another Japanese elderly cohort showed that being overweight resulted in a higher risk of death, but no influence was found between all-cause death and overweight/obese category. 18 However, there was an inverse association with the combined end point of all-cause death, stroke/transient ischemic attack, heart failure admission, and acute coronary syndrome (HR, 0.39; 95% CI, 0.13-0.89; P=0.009). 18 In this study, underweight patients were at higher risk for both major adverse events and allcause death.…”

“…18 However, there was an inverse association with the combined end point of all-cause death, stroke/transient ischemic attack, heart failure admission, and acute coronary syndrome (HR, 0.39; 95% CI, 0.13-0.89; P=0.009). 18 In this study, underweight patients were at higher risk for both major adverse events and allcause death. 18 In a subgroup analysis from the Japanese Rhythm Management Trial for Atrial Fibrillation (J-RHYTHM) registry, underweight patients were at higher risk for both cardiovascular death (HR, 2.91; 95% CI, 1.47-5.75; P=0.002) and all-cause death (HR, 2.40; 95% CI, 1.59-3.63; P<0.001), whereas overweight patients had lower risk for all-cause death (HR, 0.60; 95% CI, 0.37-0.95).…”

“…[16][17][18][19][20][21][22][23] One study included AF patients who underwent an ablation procedure for rhythm control strategy. 21 Four observational studies were based on Asian populations.…”