The Study On The Relationship Between Bone Mineral Density And Osteocalcin And Coronary Atherosclerotic Plaque Load And Coronary Calcification

Background:Cardiovascular diseases and osteoporotic fractures are both the main causes of death in old patients.In past years,the two diseases were supposed to be unrelated and independent processes associated with human aging.However in recent studies had shown there were many similar risks between atherosclerotic diseases and osteoporosis during pathogenesis and pathophysiologic progression.Although a number of prospective longitudinal cohort and epidemiological studies showed people with low bone mineral density(BMD)had a higher cardiovascular events and mortality.The association between BMD and atherosclerosis was still not clearly studied by most cross-sectional studies.Nevertheless some researches indicated the correlation between atherosclerosis and bone loss was different by ethnic or racial factors,but the relationship was still not well studied in China.Objective:1)To study the correlation between BMD,biochemical indicators of bone metabolism(such as osteocalcin)and the severity of coronary atherosclerosis,calcification.2)To find the potential novel indicators by analyzing the controversial results in previous studies.Methods:Part one:a total of 459 patients who suspected coronary heart disease(CAD),admitted for the first time coronary angiography(CAG)were selected to analyze the relationship among BMD,multivessel coronary disease,modified coronary Gensini score and severity score.Part two:Regarding to gender stratification,a total of 635 patients who suspected or diagnosed CAD,admitted for selective CAG were included to analyze the relationship between BMD and modified coronary Gensini score,and then to find the difference with the correlation between modified Gensini score and BMD.Part three:a total of 267 stable CAD patients admitted for CAG were selected to analyze the relationship between serum osteocalcin levels and severity of coronary artery stenosis.Results:1.Patients with low BMD had a higher risk of multi-vessel CAD;Both the modified Gensini score and the severity score increased with the decreased BMD,suggesting a negative correlation between coronary plaque burden and BMD.2.With the decreased BMD,coronary artery calcification score increased in postmenopausal females,but not males.There was still a significantly negative correlation between BMD and the modified Gensini score in patients without calcified coronary plaque.3.In postmenopausal females and age-matched males,serum osteocalcin levels were negatively correlated with the risk of CAD,even if it was adjusted by age and gender.However it was not significantly related when more cardiovascular risk factors were included.Conclusion:1.Our study showed that bone loss was associated with coronary atherosclerotic lesions;Patients with low BMD had more severe coronary atherosclerosis and calcification(the latter only found in females).2.Regarding to the association between atherosclerosis and bone loss,the overall coronary atherosclerotic plaque burden and distribution indicated in CAG were significantly sensitive compared with coronary calcification.3.This study indicated the serum osteocalcin levels was not an independent cardiovascular risk factor,although it had shown the negatively correlated with the severity of coronary artery stenosis.The role of osteocalcin in the progression of atherosclerosis should be evaluated by further investigations.