Parity Influence on Femur Geometry

DI GREGORIO SILVANA; DEL RIO LUIS; ZENI SUSANA N

Nashville, Tennessee. USA.

Congreso; Twenty-seventh Annual Meeting of the American Society for Bone and Mineral Research; 2005

American Society for Bone and Mineral Research.

Reproductive history affect bone mass in postmenopausal population. Previously we found that hip fracture prevalence in multiparous women was associated to a high bone mineral density (BMD). Although there are a general agreement about the relationship between hip fracture and proximal femur geometrical parameters, there are few data about the parity impact on femur geometry. A total  of 1074 post-menopausal women varying from 39 to 89 years  of age were included in the present study.  A standarized  interview was employed to obtain information on demographics parameters, life style and reproductive history. Patients were divided into four group according to the number of pregnancies: G0: 150 nulliparous (60 ±8 year), G1: 566 with one or two pregnancies (59±8 years), G2: 303 with three or four pregnancies (61 ±7years) and G3: 54 grand multiparous -five or more pregnancies- (63 ±8years). Femoral hip (total, neck and trochanter) were  evaluated by DXA GE-Lunar Prodigy V8.1). The bone status and femur geometry was assessed by using the femur strength analysis program (Lunar GE).The statistical analysis was performed by ANOVA and Pearson correlation. Results: When  nulliparous were comparing to parous women there was an statistical difference in the weight (61 vs  65 kg p < 0.0001), BMD at total hip area: 0.847 vs. 0.884 p<0.001; at trochanter: 0.658 vs. 0.686, p=0.006; at femoral neck: 0.809 vs. 0.830, p=0.045). Nulliparous women had a lower total eskeleton BMD. We didn’t found differences between geometry parameter. When the impact of pregnancies number was taken into account, BMD results showed a similar tendency: to be higher in women with more history of pregnancies, however CSA (p=0.019),  the femoral neck angle (p=0.02) and length (p=0.01) were larger in women with one or two pregnancies. The statistic Pearson test showed a positive correlation between weight and the following geometrical parameters: CSA: G0: R: 0.317 p <0001; G1: R:0.345 p < 0.001; G2: R =.324 p <0.001; G 3: R: 0.413 p < 0.002 ;  CSMI: G=: 0.347: p<0.001; G1: R: 0.337; p<0.001; G2: R:0.427 p: < 0.001; G3: NS.   Conclusion: pregnancy has an influence on proximal femur geometry and BMD, perhaps due to a macro-architectural adaptation.