Associations of non-traditional cardiovascular risk factors and body mass index with metabolic syndrome in the Chinese elderly population

Abstract

Background: Metabolic syndrome (MetS), a clustering of traditional cardiovascular risk factors (CVRF), is currently one of the major global public health burdens. However, associations between MetS and non-traditional CVRF represented by uric acid (UA), homocysteine (HCY) and hypersensitive C-reactive protein (HsCRP) have not been well explored in the elderly population, especially when considering body mass index (BMI).

Methods: Participants from the Shanghai Elderly Cardiovascular Health (SHECH) study cohort in 2017 were analyzed. MetS was defined using the modified American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Logistic regression models were used to assess associations of non-traditional CVRF, BMI with MetS.

Results: Of the 4360 participants analyzed, 2378 (54.5%) had MetS, the mean (SD) UA was 331 (86) µmol/L, and the median (IQR) HCY and HsCRP were 15 (13-18) µmol/L and 1.0 (0.5-2.1) mg/L, respectively. Participants with higher non-traditional CVRF tended to have a higher significant risk of MetS (P < 0.001), which did not changed substantially in most population subgroups (P-interaction > 0.05). BMI mediated 43.89% (95%CI: 30.38-57.40%), 37.34% (95% CI: 13.86-60.83%) and 30.99% (95%CI: 13.16-48.83%) of associations of hyperuricemia (HUA), hyperhomocysteinemia (HHCY) and high HsCRP (HHsCRP) with MetS, respectively. Abnormal non-traditional CVRF combined with overweight/obesity greatly increased MetS risk (adjusted OR(95%CI): HUA + Overweight: 5.860(4.059-8.461); 6.148(3.707-10.194); HHCY + Overweight: 3.989(3.107-5.121); HHCY + Obese: 5.746(4.064-8.123); HHsCRP + Overweight: 4.026(2.906-5.580); HHsCRP + Obese: 7.717(4.508-13.210)).

Conclusions: In the Chinese elderly population, HUA, HHCY, and HHsCRP were all significantly and independently associated with MetS, supporting the potential of focusing on non-traditional CVRF interventions for preventing and controlling MetS. BMI played moderate mediating roles in associations between non-traditional CVRF and MetS, and abnormal non-traditional CVRF combined with overweight/obesity had significant synergistic effects on MetS risk, highlighting the importance of better weight management in the elderly population.

Keywords: Body mass index; Cardiovascular disease; Metabolic syndrome; Non-traditional cardiovascular risk factors; The elderly population.