Osteoporosis Modifies the Association between Breastfeeding and Remaining Teeth in Postmenopausal Women

This study aimed to examine the association between osteoporosis, cumulative breastfeeding duration, and remaining teeth in postmenopausal women and to investigate whether osteoporosis status modifies the relationship between breastfeeding duration and oral health outcomes.

We analyzed cross-sectional data from 1,788 Korean women aged ≥50 y who participated in the 2010 to 2011 Korea National Health and Nutrition Examination Survey. Complete data were available for participants on breastfeeding duration, bone mineral density, and oral health examinations. Multiple linear regression analysis was used to assess the association between breastfeeding duration and the number of remaining teeth, stratified by osteoporosis status. Interaction analysis was conducted to examine the combined effects of osteoporosis and breastfeeding duration on tooth retention. Analyses were adjusted for potential confounding variables including age, socioeconomic factors, health behaviors, reproductive history, and oral hygiene practices.

Among participants, 36.8% (n = 658) had osteoporosis and 63.2% (n = 1,130) had normal bone mineral density. Women with osteoporosis had a significantly longer duration of breastfeeding (6.42 vs 4.09 years) and fewer remaining teeth (20.16 vs 25.42) compared with those with normal bone density. Each additional year of breastfeeding was significantly associated with fewer remaining teeth in both the normal bone density group (β = -0.39, 95% confidence interval [CI]: -0.70 to -0.08, P = 0.015) and the osteoporosis group (β = -0.52, 95% CI: -0.85 to -0.20, P = 0.002). A significant interaction between osteoporosis status and breastfeeding duration was identified (β = -0.34, P < 0.05), indicating a stronger inverse association between breastfeeding duration and remaining teeth in women with osteoporosis.

These findings suggest statistical associations between prolonged breastfeeding duration and fewer remaining teeth in postmenopausal women, with stronger associations in those with osteoporosis. The interaction effect indicates that osteoporosis status may modify this relationship, highlighting the potential need for targeted oral health monitoring in this population.Knowledge Transfer Statement:Osteoporosis modifies the association between breastfeeding and remaining teeth in postmenopausal women. Health care providers should monitor oral health in women with osteoporosis and very prolonged breastfeeding histories, although clinical relevance remains limited.