Is Tubal Ligation a Risk Factor for a Reduction of Bone Mineral Density in Postmenopausal Women? - Revista Brasileira de Ginecologia e Obstetrícia

Is Tubal Ligation a Risk Factor for a Reduction of Bone Mineral Density in Postmenopausal Women? |

Purpose: to compare bone mineral density (BMD) of postmenopausal women with and without the antecedent of tubal ligation, as well as to evaluate the associated factors that affect the bone mineral density of femur and lumbar spine of both groups. Methods: 70 postmenopausal women in each group were analyzed at CAISM-UNICAMP, during the year of 1998. All women answered a questionnaire about some clinical and reproductive characteristics and underwent bone densitometry (Lunar DPX) to measure bone mineral density of the femur and lumbar spine. Statistical analyses were performed using Student's t-test, Fisher`s exact test, Pearson c² test, Bonferroni`s test and multiple regression analysis. Results: mean age of patients was 53.2 years and for controls it was 52.6 years. Mean age of 48 years at menopause was similar in both groups. Mean age at tubal ligation surgery was 33.7 years and time since surgery was 18 years. The multiple comparison of the average bone mineral density of femur and lumbar spine did not show statistical differences between the groups. The percentage distribution of the T-score categories of femur and lumbar spine, classified into normal and altered, also did not show statistical differences between both groups. Multiple regression analysis showed that bone mineral density of femur was directly associated with body mass index, but age was indirectly associated. The variables dark skin, parity, age at menopause, educational level and body mass index were directly associated with bone mineral density of lumbar spine, but age at menarche was inversely associated. Conclusion: these findings suggest that tubal ligation does not seem to cause an additional reduction in bone mineral density when evaluated in postmenopause.