To examine the population-based incidence of any-fracture and its potential risk factors in a sex-split cohort of the Iranian population.
A total of 3,477 men and 4,085 women with a mean (SD) age of 47.92(13.1) and 45.88(11.47) years, respectively were entered into the study. The age-standardized incidence rates per 100,000 person-years were reported for the whole population and each sex separately. Cox proportional hazard models were used to estimate hazard ratios (HR) for potential risk factors. Only fractures requiring inpatients’ care were considered as the outcome. We also defined major osteoporotic fractures (MOF) as the composite of the fractures that occurred in the vertebral, wrist, hip and pelvic sites among population aged ≥50 years.
During the median (IQR) follow-up of 15.9 years, 4.34%men and 3.75% women experienced at least one incident any-fracture. The annual age-standardized incidence rates (95% CI) among men and women were 330.9 (279.6-388.9) and 319.4(268.1-377.3) per 100,000 person-years, respectively; the corresponding values for incidence of MOF was 202.2(142.3-278.6) in men and 342.01(260.4-441.0) per 100,000 person-years for women. In the multivariable model, among the whole population, age groups ≥50 years, central obesity [HR: 95% CI 1.77(1.32-2.39)], current smoking [1.59(1.15-2.20)] and using steroid medications [2.20(1.04-4.67)] significantly increased the risk of incident fracture (all P <0.05); however the impact of the first two risk factors were more prominent among women (P for interaction ≤ 0.01). Moreover, being obese was associated with a lower risk of incident first fracture in the total population [HR: 95% CI: 0.61(0.40-0.92)]. Being men [HR: 95% CI: 0.54(0.30-0.99)] and prediabetes status [HR: 95% CI: 0.53(0.30-0.95)] were also associated with lower risk for MOF.
This is the first report of long-term incidence rate of any-fracture and MOF in a conducted in the metropolitan city of Tehran. Among modifiable risk factors of fracture, in the whole population smoking habit and using steroid medications and particularly for women central obesity should be considered as main risk factors for preventive strategies. Prediabetes status was associated with lower risk of MOF.