The Relationship Between Bone Mineral Density And Cardiovascular Risk Factors In Elderly Women With Metabolic Syndrome

Background and Objective Metabolic syndrome (MS) is a complex metabolic disorder syndrome, including a variety of cardiovascular diseases and diabetes risk factors. The main components of the metabolic syndrome is obesity, diabetes or impaired glucose regulation, lipid hyperlipidemia disorders and hypertension. With the development of economy, the diet structure and lifestyle of Chinese people have changed remarkably. As a result, the prevalence of obesity, dyslipidemia and other diseases, especially central obesity are significantly increasing, which has drawn domestic and foreign scholars’attention.Osteoporosis (OP), a series of bone metabolic disorders characterized by reduced bone mass, destructive bone microstructure. It is the main reason for the morbidity and mortality among postmenopausal women and elderly men. Osteoporotic fractures usually cause pain, deformity, reduced activity, seriously affecting the quality of life of patients.Currently, the association between metabolic syndrome and OP is inconsistent. Studies about the relationship of cardiovascular risk factors, bone mineral density in elderly women with metabolic syndrome are also rare. In this study, we measured the blood pressure, blood sugar, lipid and biochemical markers of bone turnover of the elderly female population with osteoporosis, osteopenia or normal bone density. By exploring the effect of cardiovascular risk factors on the bone mineral density and their correlation among elderly female patients with metabolic syndrome, we aimed to provide a theoretical basis for the prevention of osteoporosis.Methods In this study,168 outpatient and inpatient female participants diagnosed as metabolic syndrome according to the criteria of 2005 International Diabetes Federation in Qi Lu Hospital of Shandong University from September 2011 to October 2014 were analyzed. The age ranges from 71 to 91 (mean age:77.5±5.7). The patients with secondary osteoporosis caused by diseases such as endocrine or metabolic diseases, connective tissue disease, malignant bone tumor, severe malnutrition, calcium or vitamin D malabsorption were excluded. Also, the patients with history of bone fracture or under the treatment of osteoporosis or taking drugs prone to cause osteoporosis such as glucocorticoid, immunosuppressive agents were excluded. All the participants were detected lumbar spine and hip bone mineral density by the Dual-energy X-ray absorptiometry and divided into 3 groups according to the diagnostic criteria for osteoporosis of the 1999 World Health Organization (WHO):osteoporosis group (n=68), osteopenia group (n=70), normal mineral density group (n=30). All clinical research objects were documented about the history of chronic and genetic diseases. Meanwhile, height, weight, waist circumference(WC), body mass index (BMI) and Osteoporosis Self-assessment Tool for Asians(OSTA), blood pressure, fasting plasma glucose (FPG), glycosylated hemoglobin (HbAlc), calcium(Ca), phosphorus(P), magnesium(Mg), uric acid (UA), blood urea nitrogen(BUN), creatinine(Cr), triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol(HDL-C), alkaline phosphatase(AKP), thyroid parathyroid hormone(PTH) and N-MID osteocalcin (N-MIDOs), serum beta-collagen degradation (β-CROSS), total N-terminal propeptide of type I collagen (T-P1NP) were determined. SPSS 22.0 statistical software was applied for the data analysis.Results Among osteoporosis group, osteopenia group and normal mineral density group, the height, weight, BMI, OSTA, pulse pressure, FPG, UA, HbA1c, TG, TC, LDL-C, N-MIDOs, β-CROSS, T-P1NP were significantly different(P<0.05).Compared with the normal mineral density group, the systolic blood pressure, pulse pressure FPG、HbAlc、LDL-C、N-MIDOs、β-CROSS、T-P1NP are significantly higher in osteoporosis group, while height、weight、BMI、OSTA、UA is significantly decreased than the normal group. Compared with normal mineral density group, the FPG, HbAlc, LDL-C, N-MIDOs, β-CROSS, T-P1NP significantly increased (P<0.05), and the weight, BMI, TC significantly decreased (P<0.05) in osteopenia group.The pulse pressure, FPG, TG, LDL-C, N-MIDOs,β-CROSS, T-P1NP in osteoporosis group were higher than those of ML group (P<0.05), while the weight and UA in osteoporosis group were lower than those of ML group (P<0.05).According to the Pearson correlation analysis, lumber spine bone mineral density, were positively correlated with UA, weight, BMI (r=0.45、0.40,0.42, P<0.05), and negatively with pulse pressure, FPG, HbAlc, LDL-C, N-MIDOs, β-CROSS,T-P1NP(r=--0.19、-0.25、-0.25、-0.39、-0.22、-0.25、-0.27, P<0.05). Multiple linear return analysis indicated that BMI、UA、FPG、LDL-C were independent factors for lumber spine bone mineral density.According to the Pearson correlation analysis, the bone mineral density of hip joint has a positive correlation with UA, weight, BMI, TG (r=0.35、0.35、0.34、0.15, P<0.05), while a negative correlation with pulse pressure, FPG, HbAlc, LDL-C, N-MIDOs, p-CROSS, T-P1NP (r=-0.28、-0.19、-0.23、-0.29.-0.28、-0.22,-0.29, P<0.05). Multiple linear return analysis showed that weight, pulse pressure, LDL-C were independent factors for lumber spine bone mineral density.Conclusion The bone mineral density of elderly women with metabolic syndrome is closely correlated with weight, BMI, blood pressure, blood glucose, serum lipid and uric acid. Proper control of blood pressure, blood glucose, serum lipid is in favor of prevention of osteoporosis for elderly women with metabolic syndrome.