Analysis of the relationship between complement and lipid metabolism and bone mineral density in elderly population

Abstract

Objective To investigate the diagnostic value of serum complement level and lipid metabolism level detection in senile osteoporosis. Methods A total of 215 elderly people who underwent physical examination and bone mineral density test in Beijing Jishuitan Hospital from January 2016 to June 2016 were divided into osteoporotic group(74) and non-osteoporotic group (141) according to bone mineral density classification. The relationship between serum complement C3, complement C4, low density lipoprotein cholesterol (LDL), high density lipoprotein cholesterol (HDL), triglyceride (TG), total cholesterol (CHO) and bone mineral density were analyzed. The data were analyzed by t-test, non-parametric test, binary Logistic regression and the receiver operating characteristic (ROC) curve. Results The age and CHO,LDL, HDL, complement C3 and C4 in the osteoporosis group[(80.6±8.2)years, (4.43±1.25)mmol/L, (2.27±0.73) mmol/L, (1.33±0.39) mmol/L, (1.12±0.22) g/L, (0.29±0.09)g/L], were significantly higher than those in the non-osteoporosis group[(77.5±8.3)years,(4.04±1.02)mmol/L,(1.97±0.59)mmol/L,(1.19±0.32)mmol/L,(0.86±0.25)g/L,(0.21±0.06)g/L,t-value were 2.571,-3.848,-4.483,-3.951,-1.249,-1.185,P<0.05], and the the BMI bone mineral density T-Score value of DXA and in the osteoporosis group were significantly lower than those in the non-osteoporosis group[(22.33±3.8)kg/m2, -2.74±0.78 and (25.03±4.2)kg/m2, 0.14±0.9, while the t value was 6.151 and 4.624, respectively, P<0.05]. The level of TG in osteoporotic group was significantly lower than that in non-osteoporotic group[the median (quartile) was 1.21(0.67,1.44)mmol/L and 1.37(0.86,1.67)mmol/L, respectively, Z=-2.51, P<0.01].Gender and serum levels of HDL, LDL, C3 and C4 were independent risk factors for senile osteoporosis(OR=2.476,P=0.004;OR=1.305,P=0.038;OR=1.564,P=0.028; OR=1.018, P=0.025; OR=1.023, P=0.015, respectively). The risk of osteoporosis in women was 2.476 times higher than that in men of the same age. The corresponding risk of osteoporosis increased by1.305,1.564, 1.018 and 1.023 times as HDL, LDL, C3 and C4 increased by one unit. The areas under the ROC curve detected separately by HDL, LDL, C3 and C4 were 0.623,0.595,0.673 and 0.731 respectively, and the area under the ROC curve of the four items was 0.864. Conclusions The levels of blood lipids and complements play a great role in bone metabolism. The combined detection of blood lipid metabolism and complement can improve the diagnostic efficacy of senile osteoporosis. Key words: Bone density; Complement C3; Complement C4; Lipoproteins; Triglycerides; Osteoporosis