Sarcopenic obesity and the risk of atrial fibrillation in non-diabetic older adults: A prospective cohort study

Abstract

Background

Evidence of an association between sarcopenic obesity (SO) and the risk of long-term atrial fibrillation (AF) is lacking, and the underlying involvement of insulin resistance (IR) and inflammation is not clear.

Methods

This community-based prospective cohort study evaluated sarcopenia, obesity, and baseline clinical characteristics in 4321 non-diabetic older adults between 2007 and 2011. Sarcopenia was identified using skeletal muscle mass/body weight (SMM/BW), appendicular lean mass (ALM)/BW, and handgrip strength (HGS), and obesity was identified by fat mass (FM)/BW. The association of sarcopenia and obesity with AF risk was determined by Kaplan–Meier analysis and a Cox proportional hazards model. Interaction analysis, a restricted cubic splines model, mediation analysis, and a Fine–Gray competing-risk model were also used.

Results

Over an average of 10.9 years of follow-up, 546 (11.98 per 1000 person-years) participants developed AF. Low SMM/BW, low ALM/BW, low HGS, high FM/BW, sarcopenia and obesity, were significantly associated with an increased AF risk. There was a significant synergistic relationship between sarcopenia and obesity in the increased AF risk [hazard ratio (HR): 2.029, 95 % confidence interval (CI): 1.639–2.512]. Compared with participants without sarcopenia and obesity, AF risk was the highest in those with SO (HR: 2.669, 95 % CI: 2.110–3.377], followed by sarcopenia alone (HR: 1.980, 95%CI: 1.453–2.699) and obesity (HR: 1.839, 95%CI: 1.475–2.292). Mediation analysis found that estimated glucose disposal rate (a surrogate marker of IR), high-sensitivity C-reactive protein, and galectin-3 were mediating factors in the increased AF risk caused by SO, accounting for 34.87 %, 27.56 %, and 21.05 % of the total effect, respectively.

Conclusions

SO significantly increased AF risk in these non-diabetic older individuals. Sarcopenia and obesity not only acted alone but also exhibit had a synergistic relationship to increase AF risk. IR and inflammation mediated the increased AF risk associated with SO.