RESUMO
BACKGROUND: Effects of estrogen on bone metabolism and its protective role on prevention of osteoporosis are well documented. However, the efficacy of estrogen treatment on bone healing is not well investigated. The drug can be delivered both systemically or locally to the bone with differences in concentrations and side effects. The aim of this study was to investigate the effect of local and systemic administration of estrogen on the fracture healing process. METHODS: Standardized tibial fractures with 4 millimeter gaps were created in twenty four adult male Dutch rabbits. Fractures were fixed using intramedullary wires and long leg casts. Rabbits were randomly divided into three groups. Group A was treated with twice a week administration of long acting systemic estrogen; group B was treated with a similar regimen given locally at the fracture gap; and group C received sham normal saline injections (control). Fracture healing was assessed at six weeks post fracture by gross examination, radiographic and histomorphometric analysis. RESULTS: Group B had significantly higher gross stability, radiographic union and gap reduction than the two other groups. Histomorphometric analysis showed higher cartilaginous proportion of periosteal callus area in the control group. CONCLUSIONS: Our results showed that estrogen may enhance fracture healing of long bone in rabbits. Furthermore, local estrogen treatment might have better effect than systemic treatment.
RESUMO
BACKGROUND: This study aimed to evaluate some of the major risk factors of myocardial infarction including dehydroepiandrosterone sulfate in patients with premature myocardial infarction (age <50 years old) and myocardial infarction (age ≥50 years). METHODS: This is a parallel case-control study on 50 premature myocardial infarction patients and 50 myocardial infarction patients. We also recruited 50 matched participants for each of the two groups. Patients and their control groups were assessed for dehydroepiandrosterone sulfate serum level, diabetes mellitus, hyperlipidemia, hypertriglyceridemia, and hypertension. In addition, family history of cardiovascular disease and current smoking was recorded. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of premature myocardial infarction and myocardial infarction. RESULTS: No significant differences were observed between the demographic data of patients and their controls. The dehydroepiandrosterone sulfate serum level was significantly higher in patients with premature myocardial infarction compared with controls. Multivariate logistic regression analysis revealed only serum dehydroepiandrosterone sulfate dehydroepiandrosterone sulfate level to be significantly associated with premature myocardial infarction (odds ratio, 2.65; 95% confidence interval, 1.44 to 4.877; P = 0.002). Additionally, hypertension was found to be associated with myocardial infarction. CONCLUSION: Higher levels of serum dehydroepiandrosterone sulfate level are associated with premature myocardial infarction but not with myocardial infarction, and this association is independent of the effects of other risk factors.
