Correlation of damage-associated molecular pattern molecules with age and body mass index

Abstract

Objective: To explore the correlation of damage-associated molecular pattern molecules(DAMPs) serum S100, C-reactive protein (CRP), serum amyloid A (SAA) and uric acid (UA) with age and body mass index (BMI) to provide direction for further study of metabolic inflammation and inflammaging. Methods: The observational study method was used,and three hundred and sixty-six healthy people (131 males and 235 females) were selected from the physical examination center of the Second People's Hospital of Hunan Province from May to October 2020. They were divided into three age groups according to the age interval of 20 years, including 156 (53 males and 103 females) aged 20-40 years, 110 (36 males and 74 females) aged 41-60 years, and 100 (42 males and 58 females) aged 61-80 years. Kruskal Wallis H test was used to compare the differences of serum S100, CRP, SAA and UA levels among different age groups. According to the Health Industry Standards of the People's Republic of China-Weight Determination for Adults, the boundary is BMI =24 kg/m2. The healthy people were divided into non overweight (BMI<24 kg/m2) and overweight (BMI ≥ 24 kg/m2) two groups. The 1∶1 propensity score was used to match the age and gender. There were 96 non overweight subjects [43 males, 53 females, age 52 (35, 66) years], 96 overweight subjects [44 males, 52 females, age 52 (36, 64) years]. The serum levels of S100, CRP, SAA and UA in different BMI groups were compared by Mann-Whitney U test. Results: The median serum UA concentrations in males and females were 356 and 277 μmol/L, and the levels of serum UA of male was significantly higher than that of female (Z=-10.428, P<0.001); the median serum SAA concentrations in males and females were 3.1 mg/L and 4.4 mg/L, while the serum SAA level of female was significantly higher than that of male (Z=3.652, P<0.001); for 20-40, 41-60, and 61-80 years old group, the median concentration of serum S100 was 0.058, 0.057, 0.070 μg/L, and the median concentration of serum CRP was 0.32, 0.58, 0.93 mg/L; the median serum SAA concentrations were 3.2, 4.0, 5.2 mg/L; serum uric acid concentrations were (301.8±61.5), (298.6±69.8), (329.0±77.8) μmol/L. The levels of serum S100, CRP, SAA, UA in 61-80 years group were significantly higher than those of 20-40 years group (H=-2.749, H=-6.731, H=-5.033, H=-2.521, P=0.018, P<0.001, P<0.001, P=0.035) and 41-60 years old group (H=-2.719, H=-2.539, H=-2.540, H=-2.486, P=0.020, P=0.033, P=0.033, P=0.039).The levels of serum CRP of 41-60 years group was significantly higher than that of 20-40 years group (H=-4.108,P<0.001). There was no significant difference in levels of serum S100, SAA and UA between 20-40 years group and 41-60 years group (H=0.189, H=-2.360, H=-0.165, P=1.000, P=0.055, P=1.000); the levels of serum CRP and SAA were positively correlated with age (rs =0.342, rs =0.301, P<0.001, P<0.001); for overweight, non-overweight group, the median concentrations of serum S100 were 0.065 μg/L, 0.059 μg/L, the median concentrations of serum CRP were 0.92 mg/L, 0.47 mg/L, the median concentrations of serum SAA were 5.0 mg/L, 4.1 mg/L, the median concentrations of serum UA were 339.5 μmol/L, 301.5 μmol/L, the levels of CRP, SAA and UA in the overweight group were higher than those in the non-overweight group (Z=4.278, Z=2.025, Z=3.787, P<0.001, P=0.043, P<0.001); the levels of S100 in the overweight group was higher than those in the non-overweight group, but there was no significant difference in S100 between the two groups (Z=0.862, P=0.388); the levels of Serum CRP and UA were positively correlated with BMI (rs =0.348, rs =0.264, P<0.001, P=0.009). Conclusions: With the increase of age, the serum S100, CRP, SAA and UA levels of healthy people may be on the rise, especially the serum CRP and SAA levels are positively correlated with age; the serum S100, CRP, SAA and UA levels of overweight people may be higher than those of non-overweight people, especially the serum CRP, UA levels are positively correlated with BMI.