Peso, distribución de grasa y densidad mamográfica en españolas antes y después de la menopausia

Título: Adult weight gain, fat distribution and mammographic density in Spanish pre- and post-menopausal women

Resumen:

High mammographic density (MD) is a phenotype risk marker for breast cancer. Body mass index (BMI) is inversely associated with MD, with the breast being a fat storage site. We investigated the influence of abdominal fat distribution and adult weight gain on MD, taking age, BMI and other confounders into account. Because visceral adiposity and BMI are associated with breast cancer only after menopause, differences in pre- and post-menopausal women were also explored. We recruited 3,584 women aged 45-68 years within the Spanish breast cancer screening network. Demographic, reproductive, family and personal history data were collected by purpose-trained staff, who measured current weight, height, waist and hip circumferences under the same protocol and with the same tools. MD was assessed in the left craniocaudal view using Boyd's Semiquantitative Scale. Association between waist-to-hip ratio, adult weight gain (difference between current weight and self-reported weight at 18 years) and MD was quantified by ordinal logistic regression, with random center-specific intercepts. Models were adjusted for age, BMI, breast size, time since menopause, parity, family history of breast cancer and hormonal replacement therapy use. Natural splines were used to describe the shape of the relationship between these two variables and MD. Waist-to-hip ratio was inversely associated with MD, and the effect was more pronounced in pre-menopausal (OR = 0.53 per 0.1 units; 95 % CI = 0.42-0.66) than in post-menopausal women (OR = 0.73; 95 % CI = 0.65-0.82) (P of heterogeneity = 0.010). In contrast, adult weight gain displayed a positive association with MD, which was similar in both groups (OR = 1.17 per 6 kg; 95 % CI = 1.11-1.23). Women who had gained more than 24 kg displayed higher MD (OR = 2.05; 95 % CI = 1.53-2.73). MD was also evaluated using Wolfe's and Tabar's classifications, with similar results being obtained. Once BMI, fat distribution and other confounders were considered, our results showed a clear dose-response gradient between the number of kg gained during adulthood and the proportion of dense tissue in the breast.

Direcciones:

1. Instituto de Salud Carlos III, Ctr Nacl Epidemiol, Madrid 28029 (España)

2. Dirección General de Salud Pública, Programa de Prevención del Cáncer de Mama de Valencia (España)

3. Centro Superior de Investigación en Salud Pública (CSISP), Valencia (España)

4. Instituto de Salud Pública, Programa de Detección del Cáncer de Mama, Pamplona (España)

5. Dirección General de Salud Pública SACYL, Programa de Detección Precoz del Cáncer de Mama de Castilla y León, Burgos (España)

6. Dirección General de Salud, Programa de Detección Precoz del Cáncer de Mama de las Islas Baleares (España)

7. Programa Gallego de Detección Precoz del Cáncer de Mama, La Coruña (España)

8. Servicio de Salud de Aragón, Programa de Detección Precoz del Cáncer de Mama de Aragón, Zaragoza (España)

9. Instituto Catalán de Oncología (ICO), Unidad de Prevención y Control del Cáncer, Barcelona (España)