The Changes Of Bone Density And Relevant Factors In Male Patients With Type 2 Diabetes Mellitus

Objective:Accompany with the coming of aging society, the incidence of osteoporosis is going up year by year.The mortality rate of hipbone fracture is two times higher in men than in women. Similarly, The incidences of DM have been increasing all these years with the development of economics and the change of life style. DM affects not only the metabolism of carbohydrate lipid and protein but also the metabolism of bone, so the relationship between osteoporosis and DM is mentioned more and more.Until now,many researches found Type 1 DM can make osteoporosis,but the relationship between Type 2 DM and osteoporosis is not confirmed yet. Our study is to explore the bone mineral density change in patients with T2DM and the related risk factor to provide reference for clinical prevention.Materials and Methods:We choosed 53 male patients with T2DM(1999 WHO diabetes diagnose and typing standard) hospitalized in our Endocrine Department from May 2010 to December 2010, who have got the diagonoses from 1 month to 20 years.The age of sujucets ranges from 30 to 72.Exclusion criteria were thyroid and parathyroid disease, autoimmune disease, rheumatic disease, severe renal and liver insufficiency, T1DM, long-term use of corticosteroids and thiazide diuretic, patients who are bedridden for a long time, smoke more than 15 years and other factors that can affect the metabolic of calcium and phosphorus as well as bone metabolic. All the patients' BMI are not less than 20 kg/m2. The bone mineral density (BMD) of lumbar spine, femoral neck, wards triangle,great trochanter and total proximal femur by the Dual-energy X-ray absorptionetry.All the patients is fasting more than 8 hours,and got the venous blood from ulnar.Separating the serum to mensurate fasting plasma (FPG),fasting serum insulin (FINS),glycated haemoglobin (HbA1c), total testosterone (TT), estradiol (E2), free testosterone (FT). Calculation the body mass index (BMI) by height and weight of patients:BMI=heitht/weight, and the calculation of homeostasis model assessment-insulin resistance index (HOMA-IR)=[FINS(Mu/L)×FPG(mmol/L)]/22.5. The results were statistical analysis by SPSS 13.0. The normal distribution measurement data were indicated by (x±s), and compared by t or F test, the abnomal distribution measurement data were indicated by the median and interquartile range, and compared by rank test. The relationship was analyzed by Pearson, the influence factors were analyzed by multiple stepwise regression analysis, P<0.05 means the difference has statistical significance.Results:1. Accompany with the increase of BMI,the BMD in any place was in a raising trend,and at the place of femoral neck, total proximal femur and great trochanter,the difference had statistic meaning(P<0.05).Moreover,the T score in L2,L1-4, femoral neck, total proximal femur and great trochanter were positively correlated with BMI, the difference had statistic meaning(P<0.05).2. The T stores in femur triangle area and femoral neck fell gradually with age, the difference had statistic meaning at femoral neck (P<0.05).The Z stores in any place was in a raising trend,and the difference had statistic meaning at L3,L4,L1-4 and great trochanter.The T scores in L4 were positively correlated with age.The Z scores at lumbar spine, great trochanter and total proximal femur were positively correlated with age.3. Free testosterone declined along with the bone mass reduction, the difference had statistic meaning(P<0.05).The T scores at L2,L4,L1-4, femur triangle area and total proximal femur were positively correlated with free testosterone.Multiple stepwise regression analysis showed free testosterone was the independent risk factors for BMD.4. A negative correlation was found between the Z scores in lumber spine and HOMA-IR, and between the Z scores in L4 and femur triangle area and FPG.5. No associations were observed between BMD and smoke, Duration of diabetes,HbAlc,Fins,TT and E2.Conclusion:1. The bone mass of male patients with T2DM were lower than the normal male men without diabetes.2. High body mass index was the favorable factor in maintaining bone mass. The overweight patients with T2DM should been given Appropriate calcium when they are on a diet.At the same time, optimal anti resistance movement are necessary to prevent the bone loss and reduce the incidence of fractrue.3. The measure sensitivity of BMD at hip bone are higher than lumber spine when we give the diagnosis of OP to old men.4.DM that happened on young men will make greater influence to BMD, so more attentions shoule be paid to such patients to reduce the incidence of fractrue.5. Low androgen is independent risk factors for low BMD, so the androgen measure should be tested for male patients with T2DM, and the FT may be more significative than TT.6. Except the age-related influence in the bone, a negative correlation was found between the bone mass in lumber spine and HOMA-IR, and between the bone mass in L4 and femur triangle area and FPG.So control the fasting glucose and reduce insulin resistance will help to the bone mass in lumber spine.7. No obvious associations were observed between BMD and smoke, duration of diabetes,HbA1c,FINS,TT and E2.