Abstract:
Objective To investigate the relationship between resting heart rate (RHR) and metabolic syndrome (MS) in middle-aged and elderly individuals residing in plateau regions, and to provide new scientific evidence for elucidating the influence of RHR on the mechanism of MS.
Methods From June 2021 to December 2022, a multi-stage stratified cluster sampling method was employed to select 6 269 middle-aged and elderly individuals in Xizang Autonomous Region. Based on the quartile distribution of RHR, the participants were divided into four groups: Q1 (RHR < 66.5 beats/min), Q2 (66.5 ≤ RHR ≤ 73.0 beats/min), Q3 (73.1 ≤ RHR ≤ 80.5 beats/min), and Q4 (RHR > 80.5 beats/min). Unconditional logistic regression analysis was used to explore the potential association between RHR and MS.
Results The overall prevalence of MS among the 6 269 middle-aged and elderly individuals was 22.35%. The prevalence varied across different RHR groups: 17.12% in Q1, 20.24% in Q2, 22.77% in Q3, and 29.48% in Q4, with statistically significant differences (χ2 = 74.934, P < 0.001). After adjusting for sex, age, alcohol consumption, and body mass index (BMI), compared with the RHR < 66.5 beats/min group, the risk of MS was significantly elevated in the 73.1 ≤ RHR ≤ 80.5 beats/min group (OR = 1.371, 95%CI: 1.121 - 1.678) and substantially increased in the RHR > 80.5 beats/min group (OR = 2.027, 95%CI: 1.672 - 2.482). Stratified analysis by sex and age revealed that in males, the risk of MS increased by 37.0% (OR = 1.370, 95%CI: 1.024 - 1.832) and 137.9% (OR = 2.379, 95%CI: 1.803 - 3.139) in the 73.1 ≤ RHR ≤ 80.5 beats/min and RHR > 80.5 beats/min groups, respectively. In females, the corresponding risks increased by 36.6% (OR = 1.366, 95%CI: 1.030 - 1.810) and 76.4% (OR = 1.764, 95%CI:1.328 - 2.343), respectively. When RHR > 80.5 beats/min, the risk of MS was significantly elevated in all age groups except for the 70 - 75 age group, with the highest risk observed in the 40 - 49 age group (OR = 2.777, 95%CI: 1.922 - 4.010).
Conclusions An RHR > 80.5 beats/min significantly increases the risk of MS in middle-aged and elderly individuals in plateau regions, with higher risks observed in males and individuals aged 40 - 49. RHR may be an important predictor of MS, and further investigation into its influence mechanisms in different populations is warranted.